The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infan...The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infancy and there are significant challenges to overcome.In the modern era,the scientific community is increasingly turned to natural substances due to their superior biological ability,lower cost,biodegradability,and lower toxicity than synthetic lab-made products.Chitosan is a well-known polysaccharide that has recently garnered a high amount of attention for its biological activities,especially in 3D bone tissue engineering.Chitosan closely matches the native tissues and thus stands out as a popular candidate for bioprinting.This review focuses on the potential of chitosan-based scaffolds for advancements and the drawbacks in bone treatment.Chitosan-based nanocomposites have exhibited strong mechanical strength,water-trapping ability,cellular interaction,and biodegradability.Chitosan derivatives have also encouraged and provided different routes for treatment and enhanced biological activities.3D tailored bioprinting has opened new doors for designing and manufacturing scaffolds with biological,mechanical,and topographical properties.展开更多
The combination of solar disinfection and photocatalysis technology presents a viable solution for eliminating harmful pathogenic microorganisms from water.However,some photocatalysts(e.g.,zinc oxide-based composites)...The combination of solar disinfection and photocatalysis technology presents a viable solution for eliminating harmful pathogenic microorganisms from water.However,some photocatalysts(e.g.,zinc oxide-based composites)are susceptible to pH-dependent dissolution in water,which can result in the loss of photocatalysts and additional environ-mental pollution.To obtain zinc oxide-based composites with low dissolution and high antibacterial efficiency for pho-tocatalytic water disinfection,we prepared MoS_(2)/ZnO@CS composites via a precipitation method to encapsulate chitosan(CS)around MoS_(2)/ZnO.The amino groups in the CS molecules act as storerooms for hydrogen ions,which inhibits the dissolution of zinc oxide.In addition,the MoS_(2)/ZnO@CS composites exhibit high production of reactive oxygen species(ROS)and broad-spectrum antibacterial activity under simulated solar irradiation(0.1 W·cm^(-2)).This makes it an excellent antibacterial agent for solar disinfection in water treatment.展开更多
Electrospinning has gained significant importance across various fields,including biomedicine,filtration,and packaging due to the control it provides over the properties of the resulting materials,such as fiber diamet...Electrospinning has gained significant importance across various fields,including biomedicine,filtration,and packaging due to the control it provides over the properties of the resulting materials,such as fiber diameter and membrane thickness.Chitosan is a biopolymer that can be utilized with both natural and synthetic copolymers,owing to its therapeutic potential,biocompatibility,and biodegradability.However,producing electrospun chitosan is challenging due to its high solution viscosity,which often results in the formation of beads instead of uniform fibers.To address this issue,the spinnability of chitosan is significantly enhanced,and the production of continuous nanofibers is facilitated by combining it with polymers such as polyethylene oxide(PEO)in suitable ratios.These chitosan–PEO nanofibers are primarily used in biomedical applications,including wound healing,drug delivery systems,and tissue engineering scaffolds.Additionally,they have shown promise in water treatment,filtration membranes,and packaging.Among all the nanofiber mats,chitosan/PEO-AC had the smallest fiber diameter(83±12.5 nm),chitosan/PEO_45S5 had the highest tensile strength(1611±678 MPa).This comprehensive review highlights recent advancements,ongoing challenges,and future directions in the electrospinning of chitosan-based fibers assisted by PEO.展开更多
CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS a...CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.展开更多
MicroRNAs(miRNAs)are abundant in the brain and mounting evidence suggests their involvement in the critical processes such as neurodevelopment,synaptic plasticity,and the development of neurodegenerative diseases.Thus...MicroRNAs(miRNAs)are abundant in the brain and mounting evidence suggests their involvement in the critical processes such as neurodevelopment,synaptic plasticity,and the development of neurodegenerative diseases.Thus,miRNAs may be promising therapeutic drugs for the treatment of neurodegenerative disorders.However,naked miRNAs are not able to enter cells directly,especially brain cells.Therefore,suitable carriers for safe and efficient miRNA delivery to brain cells are of great importance.Chitosan nanoparticles,with the excellent properties such as good compatibility and brilliant degradability,may act as a promising carrier for miRNA drug delivery.In this study,chitosan nanoparticles were prepared and their properties such as particle size,zeta potential and encapsulation efficiency were optimized to encapsulate miRNAs.The delivery efficiency of miRNA-loaded nanoparticles was then evaluated in both neuronal and microglia cells.The results demonstrated chitosan nanoparticles encapsulated miRNAs efficiently and showed excellent sustained releasing in vitro.Moreover,chitosan nanoparticles delivered miRNA to both neurons and microglia with very low toxicity and high efficiency.In conclusion,chitosan nanoparticles are promising carriers for the delivery of miRNAs to brain cells,which may be used for the early intervention and treatment of neurodegenerative disorders.展开更多
Objective:To develop chitosan-silver nanoparticles targeting Pseudomonas aeruginosa biofilms and verify their antibacterial performance through animal experiments.Methods:Chitosan,silver nitrate,glacial acetic acid,an...Objective:To develop chitosan-silver nanoparticles targeting Pseudomonas aeruginosa biofilms and verify their antibacterial performance through animal experiments.Methods:Chitosan,silver nitrate,glacial acetic acid,and other chemical reagents were used to synthesize chitosan-silver nanoparticles.The characterization,minimum inhibitory concentration,and biofilm inhibition rate of the chitosan-silver nanoparticles were tested.A total of 40 SD rats were randomly divided into four groups.After routine adaptive feeding,the control group received intraperitoneal injection of normal saline;the model group received intraperitoneal injection of Pseudomonas aeruginosa suspension;the positive group received intraperitoneal injection of Pseudomonas aeruginosa suspension mixed with ampicillin at a volume ratio of 1∶1;the observation group received intraperitoneal injection of Pseudomonas aeruginosa suspension mixed with chitosan-silver nanoparticles(at minimum inhibitory concentration)at a volume ratio of 1∶1.Bacterial load,inflammatory factors,and liver and kidney function indicators in tissues were observed and compared among the four groups on the 3^(rd)day after treatment.Results:When the concentration of chitosansilver nanoparticles reached 8μg/mL or above,the OD value of the experimental wells was close to that of the control wells,indicating that 8μg/mL was the minimum inhibitory concentration of the chitosan-silver nanoparticles;at concentrations of 8μg/mL or above,the biofilm inhibition rate was greater than 80%.The bacterial load in the observation group was significantly lower than that in the model and positive groups(P<0.05).The expression levels of interleukin-6,interferon-γ,and tumor necrosis factor-αin the observation group were significantly lower than those in the model and positive groups(P<0.05).There were no statistically significant differences in alanine aminotransferase,aspartate aminotransferase,blood urea nitrogen,and creatinine levels among the four groups(P>0.05).Conclusion:The chitosan-silver nanoparticles targeting Pseudomonas aeruginosa biofilms constructed in this study exhibit good antibacterial effects against Pseudomonas aeruginosa and have good safety.展开更多
The continuous increase in petroleum-based plastic food packaging has led to numerous environmental concerns.One effort to reduce the use of plastic packaging in food is through preservation using biopolymer-based pac...The continuous increase in petroleum-based plastic food packaging has led to numerous environmental concerns.One effort to reduce the use of plastic packaging in food is through preservation using biopolymer-based packaging.Among the many types of biopolymers,chitosan is widely used and researched due to its non-toxic,antimicrobial,and antifungal properties.Chitosan is widely available since it is a compound extracted from seafood waste,especially shrimps and crabs.The biodegradability and biocompatibility of chitosan also showed good potential for various applications.These characteristics and propertiesmake chitosan an attractive biopolymer to be implemented as food packaging in films and coatings.Chitosan has been tested in maintaining and increasing the shelf life of food,especially seafood such as fish and shrimp,and post-harvest products such as fruits and vegetables.In addition to its various advantages,the properties and characteristics of chitosan need to be improved to produce optimal preservation.The properties and characteristics of chitosan are improved by adding various types of additive materials such as biopolymers,plant extracts,essential oils,and metal nanoparticles.Research shows that material additives and nanotechnology can improve the quality of chitosan-based food packaging for various types of food by enhancing mechanical properties,thermal stability,antimicrobial activity,and antioxidant activity.This review provides a perspective on the recent development and properties enhancement of chitosan composite with additives and nanotechnology,as well as this material’s challenges and prospects as food packaging.展开更多
Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materia...Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.展开更多
Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,...Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,and the competing hydrogen evolution reaction.To address these issues,we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes(CNTs)with chitosan through a simple and scalable scraping process.The CNTs ensure uniform electric field distribution due to their high electrical conductivity,while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface.The chitosan/CNTs composite layer also facilitates smooth Zn^(2+)deposition,enhancing the stability and reversibility of the Zn anode.As a result,the chitosan/CNTs@Zn anode demonstrates exceptional cycling stability,achieving over 3000 h of plating/stripping with minimal degradation.When paired with a V_(2)O_(5)cathode,the composite-protected anode significantly improves the cycle stability and energy density of the full cell.Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions.This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries,paving the way for their practical application in next-generation energy storage systems.展开更多
Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.T...Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.This study was conducted to evaluate the protective efficiency of cinnamaldehyde-loaded chitosan nanoparticles(Cin@CSNPs)against oxidative damage and genotoxicity of ZnO-NPs in mice.ZnO-NPs were biosynthesized using the extract of fresh leaves of Mentha pulegium L.Cin was extracted from cinnamon essential oil,and was loaded into chitosan nanoparticle(Cin@CSNPs).Both ZnO-NPs,Cin@CSNPs and CSNPs were characterized.The in vitro release of Cin@CSNPs was determined.In the biological study,6 groups of male BALB/c mice were treated by gavage for 3 weeks as follows,control group,the group received ZnO-NPs(25 mg/kg b.w),the groups received Cin@CSNPs at low dose(50 mg/kg b.w)or high dose(100 mg/kg b.w),and the groups received ZnO-NPs plus Cin@CSNPs at the 2 tested doses.Blood and tissue samples were collected for different biochemical,genetical and histological studies.The particle size of ZnO-NPs,CSNPs,and Cin@CSNPs were(20.78±2.60),(170.0±3.7),and(218.23±2.90)nm,andξ-potential were(32.7±4.6),(8.32±0.27)and(4.80±0.21)mV,respectively.ZnO-NPs disturbed the biochemical and oxidative stress indices,AFP,CEA,TNF-α,chromosomal aberrations in somatic and germ cells,and sperm abnormality along with severe pathological changes in the hepatic,renal,and testicular tissues.Cin@CSNPs improved significantly all the parameters tested and the histological picture in a dose-dependent.Therefore,the biosynthesized ZnO-NPs exhibit oxidative damage and genotoxicity,and Cin@CSNPs have potential protective effects against the risks of ZnO-NPs and may be a promising tool to overcome the challenges of using Cin in food and pharmaceuticals applications.展开更多
Objective:To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch.(G.uralensis)and to improve the quality of cultivated G.uralensis for both medicine and food and aid in...Objective:To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch.(G.uralensis)and to improve the quality of cultivated G.uralensis for both medicine and food and aid in the increase in the content of effective components in G.uralensis.Methods:In this study,whole G.uralensis plants were treated with exogenous chitosan,and compre-hensive analyses of secondary metabolites and proteins were conducted using liquid chromatography with tandem mass spectrometry and isobaric tag for relative and absolute quantitation,respectively.Effects of chitosan induction on endogenous hormones of G.uralensis were analyzed using an enzyme-linked immunosorbent assay.Gene ontology function annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation were conducted to study the effect of chitosan induction on the proteome.Results:Chitosan induction significantly increased the levels of flavonoids in G.uralensis;however,the variation in triterpenoids was not substantial.Biological processes,including photosynthesis,secondary metabolism,and abiotic stress responses,were significantly enriched.Additionally,the photosynthetic pathway,photosynthesis-antenna protein pathway,and plant hormone signal transduction pathway were significantly enriched.In the flavonoid biosynthesis pathway,the upstream-related enzyme phenylalanine ammonia-lyase(PAL)and the downstream-related enzymes chalcone synthase(CHS),polyketide reductase(PKR),chalcone isomerase(CHI),and vestitone reductase(VR)were significantly upregulated.Conclusions:Our findings suggest that chitosan induction may promote the tricarboxylic acid(TCA)cycle,and the TCA cycle enhancement significantly upregulated PAL,CHS,PKR,CHI,and VR,the five key enzymes involved in flavonoid synthesis of G.uralensis,indicating that chitosan induction activated the entire metabolic pathway associated with flavonoids in G.uralensis.Our findings provide a reference for improving the quality of cultivated G.uralensis from the perspective of pharmacodynamic components.展开更多
Polylactic acid(PLA),a biodegradable polymer,exhibits superior mechanical strength and processability.However,its broader adoption is hindered by inherent brittleness,low hydrophilicity,and sluggish crystallization ki...Polylactic acid(PLA),a biodegradable polymer,exhibits superior mechanical strength and processability.However,its broader adoption is hindered by inherent brittleness,low hydrophilicity,and sluggish crystallization kinetics.Chitosan(CS),a natural polysaccharide renowned for its biocompatibility and biodegradability,offers potential to address these limitations.While both materials have garnered significant attention in materials science,research on their integration via melt blending and the resulting performance enhancements for food-contact plastics remains understudied.This research comprehensively explores how different levels of CS content,from 0% to 10%,impact the characteristics of chitosan/polylactic acid(CS/PLA)composites.It specifically analyzes the influence of various CS concentrations on the mechanical attributes,crystallization behavior,thermomechanical properties,and rheological performance of these composites.The study concludes that a CS content of 4% in the CS/PLA composite results in the best overall properties.At this point,its elongation at break and impact strength reached theirmaximum values(16.16% and 20.63 kJ/m^(2)),representing increases of 23.9% and 15.7% compared to pure PLA.At this particular concentration,CS is evenly distributed throughout the PLA matrix,acting as a heterogeneous nucleating agent.It facilitates the crystallization of the composite material and offers effective reinforcement.This study presents a promising approach for developing environmentally friendly and sustainable alternatives to fossil-based plastics,highlighting significant research value and practical application potential.展开更多
Aqueous zinc-ion batteries encounter enormous challenges such as Zn dendrites and parasitic reactions.Separator modification is a highly effective strategy to address these issues.With the advantages of low cost,nonto...Aqueous zinc-ion batteries encounter enormous challenges such as Zn dendrites and parasitic reactions.Separator modification is a highly effective strategy to address these issues.With the advantages of low cost,nontoxicity,biodegradability,good film-forming ability,superior hydro phi licity,and rich functional groups,chitosan is an ideal matrix for constructing separators.However,the presence of positive charges within chitosan in weakly acidic electrolytes is unfavorable for dendrite inhibition.Herein,Schiff base reaction is introduced to modify chitosan matrix,transforming its charge polarity from positive to negative.Additionally,NbN with excellent zincophilicity is coated onto chitosan matrix,forming a Janus separator with low thickness of 19μm and considerably improved mechanical properties.The resultant separator can promote the transport of Zn^(2+)ions while triggering a repulsive shielding effect against anions,therefore dramatically enhancing Zn^(2+)ion transfer number from 0.28 to 0.49.This separator can also facilitate desolvation process,improve exchange current density,restrict two-dimensional Zn^(2+)ion diffusion,and enhance electrochemical kinetics,contributing to significantly inhibited dendrite growth,by-product formation,and hydrogen evolution.Consequently,stable and reversible Zn stripping/plating process is enabled for over 2500 h at 2 mA cm^(-2)and 2 mAh cm^(-2).And great rate capability and excellent cyclability can be achieved for full batteries even under harsh conditions.This work provides new insights into separator design for Zn-based batteries.展开更多
The purpose of this research work is to determine the removal efficiency of Cu^(2+)and Pb^(2+)ions using polyvinyl alcohol/neem leaf extract/chitosan(PVA/NLE/CS)composite films as adsorbent materials from an aqueous m...The purpose of this research work is to determine the removal efficiency of Cu^(2+)and Pb^(2+)ions using polyvinyl alcohol/neem leaf extract/chitosan(PVA/NLE/CS)composite films as adsorbent materials from an aqueous medium,with respect to pH,contact time,and adsorbent dosage.The synthesized composite material was characterized using Fourier Transform Infrared(FTIR)spectroscopy,thermogravimetric analysis-Derivative Thermogravimetry(TGA-DTG),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy-Energy Dispersive X-ray Spectroscopy(SEM-EDX).The antibacterial activity and swelling response of the material were studied using suitable methodologies.The FTIR study confirmed the interactions among PVA,chitosan,and neem leaf extract.The TGA data reveal the excellent thermal stability of the developed composite films.The SEM micrograph indicates a homogeneous phase morphology with good compatibility among chitosan,the monomer,and the leaf extract.The antibacterial study revealed that the prepared PVA/NLE/CS films exhibit improved antibacterial activity against bacterial growth.It was found that at pH 6.0,the adsorption capacity for both toxic metal ions is maximum,and decreases with a further rise in pH.At this pH,the adsorption capacity of PVA/NLE/CS films increases with a gradual increase in adsorbent dosage,and at a specific pH,the adsorption capacity for Cu^(2+)is greater than that for Pb^(2+).The adsorption efficiency is a function of contact time and was found to be maximal at 180 min.Hence,the developed composite material is effective for the removal of metal ions from wastewater.展开更多
It is well known that adsorbent material is the key to determine the CO_(2)adsorption performance.Herein,ZIF-8 derived porous carbon(ZIF-8-C)is anchored into the framework of a novel composite aerogel(ZCPx),which util...It is well known that adsorbent material is the key to determine the CO_(2)adsorption performance.Herein,ZIF-8 derived porous carbon(ZIF-8-C)is anchored into the framework of a novel composite aerogel(ZCPx),which utilizes chitosan(CS)and polyvinyl alcohol(PVA)as raw materials.By controlling the ratio of ZIF-8-C,the developed hierarchical porous structures combine the advantages of micropores,mesopores,and macropores.Besides,the ligand material of ZIF-8-C and the amino group from CS are two sources of the high nitrogen content of ZCPx.The optimized sample ZCP4 shows a high nitrogen content of 6.78%,which can create more active centers and supply basic sites,thereby enhancing the CO_(2)adsorption capacity.Moreover,ZC P4 composite aerogel presents a CO_(2)adsorption capacity of2.26 mmol·g^(-1)(298 K,0.1 MPa)and CO_(2)/N_(2)selectivity(S_(CO_(2))/N_(2))can reach 20.02,and the dynamic breakthrough experiment is performed to confirm the feasibility of CO_(2)/N_(2)actual separation performance,proving that the composite aerogel is potential candidates for CO_(2)adsorption.展开更多
Adipose-derived stem cell,one type of mesenchymal stem cells,is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery.However,its application has been limited b...Adipose-derived stem cell,one type of mesenchymal stem cells,is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery.However,its application has been limited by the complexities of the ischemic microenvironment.Hydrogel scaffolds,which are composed of hyaluronic acid and chitosan,exhibit excellent biocompatibility and biodegradability,making them promising candidates as cell carriers.Vascular endothelial growth factor is a crucial regulatory factor for stem cells.Both hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells,thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of stroke.Here,we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem cells.Subsequently,we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemiareperfusion injury.When loaded with adipose-derived stem cells,this vascular endothelial growth factor–loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon morphology.Further in vivo experiments revealed that this vascular endothelial growth factor–loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells,leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery occlusion.It also helped maintain mitochondrial integrity and axonal morphology,greatly improving rat motor function and angiogenesis.Therefore,utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment on transplanted stem cells and enhance the therapeutic effect of stem cells in the context of stroke.展开更多
Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse...Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse model of Parkinson's disease and found that it effectively reduced dopamine neuron injury, neurotransmitter dopamine release, and motor symptoms. These neuroprotective effects of chitosan were related to bacterial metabolites, specifically shortchain fatty acids, and chitosan administration altered intestinal microbial diversity and decreased short-chain fatty acid production in the gut. Furthermore, chitosan effectively reduced damage to the intestinal barrier and the blood–brain barrier. Finally, we demonstrated that chitosan improved intestinal barrier function and alleviated inflammation in both the peripheral nervous system and the central nervous system by reducing acetate levels. Based on these findings, we suggest a molecular mechanism by which chitosan decreases inflammation through reducing acetate levels and repairing the intestinal and blood–brain barriers, thereby alleviating symptoms of Parkinson's disease.展开更多
Background:Chitosan oligosaccharide(COS)is the major degradation product of chitosan by enzymatic processes.COS,with complete water solubility,exerts significant biological effects,including anti-cancer activity.We in...Background:Chitosan oligosaccharide(COS)is the major degradation product of chitosan by enzymatic processes.COS,with complete water solubility,exerts significant biological effects,including anti-cancer activity.We investigated the anti-tumor effects of COS on colorectal cancer as effective therapeutic methods with low side effects are lacking.Methods:COS was obtained from low molecular weight chitosan by an enzymatic method and the anticancer effects were measured by cell viability assay,flow cytometry analysis,Western blotting,and xenograft.Results:COS suppressed the proliferation of SNU-C5 cells compared to other colorectal cancer cells,but higher concentrations were required in the xenograft model.Co-treatment with 5-fluorouracil(5-FU)and COS enhanced the anti-cancer effects of 5-FU in SNU-C5 cells in vitro and in vivo.Flow cytometry revealed that COS induced cell cycle arrest at the G0/G1 phase without 5-FU or at the S and G2/M phases with 5-FU but did not affect cell death pathways.COS increased extracellular signal-regulated protein kinase(ERK)activation with or without 5-FU,whereas 5-FU treatment increased p53 activation.A low-dose of an ERK inhibitor suppressed COS-induced ERK activation and resulted in higher proliferation compared with COS.Conclusions:These results suggest that COS might enhance the anti-cancer effects of 5-FU in SNU-C5 colorectal cancer cells by activating ERK.展开更多
Attempts have been made to use cell transplantation and biomaterials to promote cell proliferation,differentiation,migration,and survival,as well as angiogenesis,in the context of brain injury.However,whether bioactiv...Attempts have been made to use cell transplantation and biomaterials to promote cell proliferation,differentiation,migration,and survival,as well as angiogenesis,in the context of brain injury.However,whether bioactive materials can repair the damage caused by ischemic stroke by activating endogenous neurogenesis and angiogenesis is still unknown.In this study,we applied chitosan gel loaded with basic fibroblast growth factor to the stroke cavity 7 days after ischemic stroke in rats.The gel slowly released basic fibroblast growth factor,which improved the local microenvironment,activated endogenous neural stem/progenitor cells,and recruited these cells to migrate toward the penumbra and stroke cavity and subsequently differentiate into neurons,while enhancing angiogenesis in the penumbra and stroke cavity and ultimately leading to partial functional recovery.This study revealed the mechanism by which bioactive materials repair ischemic strokes,thus providing a new strategy for the clinical application of bioactive materials in the treatment of ischemic stroke.展开更多
Chitooligosaccharides(COS)find numerous applications due to their exceptional properties.Enzymatic hydrolysis of chitosan by chitosanase is considered an advantageous route for COS production.Heterologous expression o...Chitooligosaccharides(COS)find numerous applications due to their exceptional properties.Enzymatic hydrolysis of chitosan by chitosanase is considered an advantageous route for COS production.Heterologous expression of chitosanase holds significant promise,yet studies using commonly employed Escherichia coli and Pichia pasto-ris strains encounter challenges in subsequent handling and industrial scalability.In this investigation,we opted for using the safe yeast strain Saccharomyces cerevisiae(GRAS),obviating the need for methanol induction,resulting in successful expression.Ultimately,utilizing the GTR-CRISPR editing system,shake flask enzyme activity reached 2 U/ml.The optimal chitosanase activity was achieved at 55℃and pH 5,with favorable stability between 30 and 50°C.Following a 2-h catalytic reaction,the product primarily consisted of chitobiose to chitotetraose,predominantly at the chitotriose position,with a slight increase in chitobiose content observed during the later stages of enzymatic hydrolysis.The results affirm the feasibility of heterologous chitosanase expression through Saccharomyces cerevisiae,underscoring its significant industrial potential.展开更多
文摘The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infancy and there are significant challenges to overcome.In the modern era,the scientific community is increasingly turned to natural substances due to their superior biological ability,lower cost,biodegradability,and lower toxicity than synthetic lab-made products.Chitosan is a well-known polysaccharide that has recently garnered a high amount of attention for its biological activities,especially in 3D bone tissue engineering.Chitosan closely matches the native tissues and thus stands out as a popular candidate for bioprinting.This review focuses on the potential of chitosan-based scaffolds for advancements and the drawbacks in bone treatment.Chitosan-based nanocomposites have exhibited strong mechanical strength,water-trapping ability,cellular interaction,and biodegradability.Chitosan derivatives have also encouraged and provided different routes for treatment and enhanced biological activities.3D tailored bioprinting has opened new doors for designing and manufacturing scaffolds with biological,mechanical,and topographical properties.
基金supported in part by the National Natural Science Foundation of China(12174366)Fundamental Re-search Funds for the Central Universities(WK3450000005)the Anhui Provincial Natural Science Foundation(2108085MC93).
文摘The combination of solar disinfection and photocatalysis technology presents a viable solution for eliminating harmful pathogenic microorganisms from water.However,some photocatalysts(e.g.,zinc oxide-based composites)are susceptible to pH-dependent dissolution in water,which can result in the loss of photocatalysts and additional environ-mental pollution.To obtain zinc oxide-based composites with low dissolution and high antibacterial efficiency for pho-tocatalytic water disinfection,we prepared MoS_(2)/ZnO@CS composites via a precipitation method to encapsulate chitosan(CS)around MoS_(2)/ZnO.The amino groups in the CS molecules act as storerooms for hydrogen ions,which inhibits the dissolution of zinc oxide.In addition,the MoS_(2)/ZnO@CS composites exhibit high production of reactive oxygen species(ROS)and broad-spectrum antibacterial activity under simulated solar irradiation(0.1 W·cm^(-2)).This makes it an excellent antibacterial agent for solar disinfection in water treatment.
文摘Electrospinning has gained significant importance across various fields,including biomedicine,filtration,and packaging due to the control it provides over the properties of the resulting materials,such as fiber diameter and membrane thickness.Chitosan is a biopolymer that can be utilized with both natural and synthetic copolymers,owing to its therapeutic potential,biocompatibility,and biodegradability.However,producing electrospun chitosan is challenging due to its high solution viscosity,which often results in the formation of beads instead of uniform fibers.To address this issue,the spinnability of chitosan is significantly enhanced,and the production of continuous nanofibers is facilitated by combining it with polymers such as polyethylene oxide(PEO)in suitable ratios.These chitosan–PEO nanofibers are primarily used in biomedical applications,including wound healing,drug delivery systems,and tissue engineering scaffolds.Additionally,they have shown promise in water treatment,filtration membranes,and packaging.Among all the nanofiber mats,chitosan/PEO-AC had the smallest fiber diameter(83±12.5 nm),chitosan/PEO_45S5 had the highest tensile strength(1611±678 MPa).This comprehensive review highlights recent advancements,ongoing challenges,and future directions in the electrospinning of chitosan-based fibers assisted by PEO.
基金MOHE (FRGS/1/2023/STG05/UITM/01/3) for funding support
文摘CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.
基金supported financially by the NSFC(Nos.62075098 and 62071119)the National Key Research and Development Program of China(Nos.2017YFA0205301 and 2018YFC1602905)。
文摘MicroRNAs(miRNAs)are abundant in the brain and mounting evidence suggests their involvement in the critical processes such as neurodevelopment,synaptic plasticity,and the development of neurodegenerative diseases.Thus,miRNAs may be promising therapeutic drugs for the treatment of neurodegenerative disorders.However,naked miRNAs are not able to enter cells directly,especially brain cells.Therefore,suitable carriers for safe and efficient miRNA delivery to brain cells are of great importance.Chitosan nanoparticles,with the excellent properties such as good compatibility and brilliant degradability,may act as a promising carrier for miRNA drug delivery.In this study,chitosan nanoparticles were prepared and their properties such as particle size,zeta potential and encapsulation efficiency were optimized to encapsulate miRNAs.The delivery efficiency of miRNA-loaded nanoparticles was then evaluated in both neuronal and microglia cells.The results demonstrated chitosan nanoparticles encapsulated miRNAs efficiently and showed excellent sustained releasing in vitro.Moreover,chitosan nanoparticles delivered miRNA to both neurons and microglia with very low toxicity and high efficiency.In conclusion,chitosan nanoparticles are promising carriers for the delivery of miRNAs to brain cells,which may be used for the early intervention and treatment of neurodegenerative disorders.
文摘Objective:To develop chitosan-silver nanoparticles targeting Pseudomonas aeruginosa biofilms and verify their antibacterial performance through animal experiments.Methods:Chitosan,silver nitrate,glacial acetic acid,and other chemical reagents were used to synthesize chitosan-silver nanoparticles.The characterization,minimum inhibitory concentration,and biofilm inhibition rate of the chitosan-silver nanoparticles were tested.A total of 40 SD rats were randomly divided into four groups.After routine adaptive feeding,the control group received intraperitoneal injection of normal saline;the model group received intraperitoneal injection of Pseudomonas aeruginosa suspension;the positive group received intraperitoneal injection of Pseudomonas aeruginosa suspension mixed with ampicillin at a volume ratio of 1∶1;the observation group received intraperitoneal injection of Pseudomonas aeruginosa suspension mixed with chitosan-silver nanoparticles(at minimum inhibitory concentration)at a volume ratio of 1∶1.Bacterial load,inflammatory factors,and liver and kidney function indicators in tissues were observed and compared among the four groups on the 3^(rd)day after treatment.Results:When the concentration of chitosansilver nanoparticles reached 8μg/mL or above,the OD value of the experimental wells was close to that of the control wells,indicating that 8μg/mL was the minimum inhibitory concentration of the chitosan-silver nanoparticles;at concentrations of 8μg/mL or above,the biofilm inhibition rate was greater than 80%.The bacterial load in the observation group was significantly lower than that in the model and positive groups(P<0.05).The expression levels of interleukin-6,interferon-γ,and tumor necrosis factor-αin the observation group were significantly lower than those in the model and positive groups(P<0.05).There were no statistically significant differences in alanine aminotransferase,aspartate aminotransferase,blood urea nitrogen,and creatinine levels among the four groups(P>0.05).Conclusion:The chitosan-silver nanoparticles targeting Pseudomonas aeruginosa biofilms constructed in this study exhibit good antibacterial effects against Pseudomonas aeruginosa and have good safety.
基金Penelitian Tesis Magister(PTM)Research Grant from Indonesian Government Kemdikbudristek with contract number 036/E5/PG.02.00.PL/2024.PPM1 2024 Research Grant from Faculty of Industrial Technology,ITB.
文摘The continuous increase in petroleum-based plastic food packaging has led to numerous environmental concerns.One effort to reduce the use of plastic packaging in food is through preservation using biopolymer-based packaging.Among the many types of biopolymers,chitosan is widely used and researched due to its non-toxic,antimicrobial,and antifungal properties.Chitosan is widely available since it is a compound extracted from seafood waste,especially shrimps and crabs.The biodegradability and biocompatibility of chitosan also showed good potential for various applications.These characteristics and propertiesmake chitosan an attractive biopolymer to be implemented as food packaging in films and coatings.Chitosan has been tested in maintaining and increasing the shelf life of food,especially seafood such as fish and shrimp,and post-harvest products such as fruits and vegetables.In addition to its various advantages,the properties and characteristics of chitosan need to be improved to produce optimal preservation.The properties and characteristics of chitosan are improved by adding various types of additive materials such as biopolymers,plant extracts,essential oils,and metal nanoparticles.Research shows that material additives and nanotechnology can improve the quality of chitosan-based food packaging for various types of food by enhancing mechanical properties,thermal stability,antimicrobial activity,and antioxidant activity.This review provides a perspective on the recent development and properties enhancement of chitosan composite with additives and nanotechnology,as well as this material’s challenges and prospects as food packaging.
基金funded by the joint research collaboration of the Research Organization of Agriculture and Food National Research and Innovation Agency(BRIN)FY 2024(Grant number:6/III.11/HK/2024),with Widya Fatriasari as the Principal Investigator.
文摘Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.
基金supported by the National Natural Science Foundation of China(22279139,62227815,22465026,22469015)the National Key R&D Program of China(2022YFA1504500)+1 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region of China(2024JQ06,2022MS2010,2024MS05005)Inner Mongolia University Postgraduate Scientific Research Innovation Project(11200-5223737)。
文摘Rechargeable aqueous zinc(Zn)-metal batteries hold great promise for next-generation energy storage systems.However,their practical application is hindered by several challenges,including dendrite formation,corrosion,and the competing hydrogen evolution reaction.To address these issues,we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes(CNTs)with chitosan through a simple and scalable scraping process.The CNTs ensure uniform electric field distribution due to their high electrical conductivity,while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface.The chitosan/CNTs composite layer also facilitates smooth Zn^(2+)deposition,enhancing the stability and reversibility of the Zn anode.As a result,the chitosan/CNTs@Zn anode demonstrates exceptional cycling stability,achieving over 3000 h of plating/stripping with minimal degradation.When paired with a V_(2)O_(5)cathode,the composite-protected anode significantly improves the cycle stability and energy density of the full cell.Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions.This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries,paving the way for their practical application in next-generation energy storage systems.
基金supported by the National Research Centre,Dokki,Cairo,Egypt project#13050302.
文摘Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.This study was conducted to evaluate the protective efficiency of cinnamaldehyde-loaded chitosan nanoparticles(Cin@CSNPs)against oxidative damage and genotoxicity of ZnO-NPs in mice.ZnO-NPs were biosynthesized using the extract of fresh leaves of Mentha pulegium L.Cin was extracted from cinnamon essential oil,and was loaded into chitosan nanoparticle(Cin@CSNPs).Both ZnO-NPs,Cin@CSNPs and CSNPs were characterized.The in vitro release of Cin@CSNPs was determined.In the biological study,6 groups of male BALB/c mice were treated by gavage for 3 weeks as follows,control group,the group received ZnO-NPs(25 mg/kg b.w),the groups received Cin@CSNPs at low dose(50 mg/kg b.w)or high dose(100 mg/kg b.w),and the groups received ZnO-NPs plus Cin@CSNPs at the 2 tested doses.Blood and tissue samples were collected for different biochemical,genetical and histological studies.The particle size of ZnO-NPs,CSNPs,and Cin@CSNPs were(20.78±2.60),(170.0±3.7),and(218.23±2.90)nm,andξ-potential were(32.7±4.6),(8.32±0.27)and(4.80±0.21)mV,respectively.ZnO-NPs disturbed the biochemical and oxidative stress indices,AFP,CEA,TNF-α,chromosomal aberrations in somatic and germ cells,and sperm abnormality along with severe pathological changes in the hepatic,renal,and testicular tissues.Cin@CSNPs improved significantly all the parameters tested and the histological picture in a dose-dependent.Therefore,the biosynthesized ZnO-NPs exhibit oxidative damage and genotoxicity,and Cin@CSNPs have potential protective effects against the risks of ZnO-NPs and may be a promising tool to overcome the challenges of using Cin in food and pharmaceuticals applications.
基金supported by grants from the National Natural Science Foundation of China(81773838).
文摘Objective:To explore the impact of exogenous chitosan on the growth and metabolism of Glycyrrhiza uralensis Fisch.(G.uralensis)and to improve the quality of cultivated G.uralensis for both medicine and food and aid in the increase in the content of effective components in G.uralensis.Methods:In this study,whole G.uralensis plants were treated with exogenous chitosan,and compre-hensive analyses of secondary metabolites and proteins were conducted using liquid chromatography with tandem mass spectrometry and isobaric tag for relative and absolute quantitation,respectively.Effects of chitosan induction on endogenous hormones of G.uralensis were analyzed using an enzyme-linked immunosorbent assay.Gene ontology function annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation were conducted to study the effect of chitosan induction on the proteome.Results:Chitosan induction significantly increased the levels of flavonoids in G.uralensis;however,the variation in triterpenoids was not substantial.Biological processes,including photosynthesis,secondary metabolism,and abiotic stress responses,were significantly enriched.Additionally,the photosynthetic pathway,photosynthesis-antenna protein pathway,and plant hormone signal transduction pathway were significantly enriched.In the flavonoid biosynthesis pathway,the upstream-related enzyme phenylalanine ammonia-lyase(PAL)and the downstream-related enzymes chalcone synthase(CHS),polyketide reductase(PKR),chalcone isomerase(CHI),and vestitone reductase(VR)were significantly upregulated.Conclusions:Our findings suggest that chitosan induction may promote the tricarboxylic acid(TCA)cycle,and the TCA cycle enhancement significantly upregulated PAL,CHS,PKR,CHI,and VR,the five key enzymes involved in flavonoid synthesis of G.uralensis,indicating that chitosan induction activated the entire metabolic pathway associated with flavonoids in G.uralensis.Our findings provide a reference for improving the quality of cultivated G.uralensis from the perspective of pharmacodynamic components.
基金funded by National Natural Science Foundation of China(NSFC),grant number(No.U2341237).
文摘Polylactic acid(PLA),a biodegradable polymer,exhibits superior mechanical strength and processability.However,its broader adoption is hindered by inherent brittleness,low hydrophilicity,and sluggish crystallization kinetics.Chitosan(CS),a natural polysaccharide renowned for its biocompatibility and biodegradability,offers potential to address these limitations.While both materials have garnered significant attention in materials science,research on their integration via melt blending and the resulting performance enhancements for food-contact plastics remains understudied.This research comprehensively explores how different levels of CS content,from 0% to 10%,impact the characteristics of chitosan/polylactic acid(CS/PLA)composites.It specifically analyzes the influence of various CS concentrations on the mechanical attributes,crystallization behavior,thermomechanical properties,and rheological performance of these composites.The study concludes that a CS content of 4% in the CS/PLA composite results in the best overall properties.At this point,its elongation at break and impact strength reached theirmaximum values(16.16% and 20.63 kJ/m^(2)),representing increases of 23.9% and 15.7% compared to pure PLA.At this particular concentration,CS is evenly distributed throughout the PLA matrix,acting as a heterogeneous nucleating agent.It facilitates the crystallization of the composite material and offers effective reinforcement.This study presents a promising approach for developing environmentally friendly and sustainable alternatives to fossil-based plastics,highlighting significant research value and practical application potential.
基金the financial support from the Natural Science Foundation of Jiangsu Province(BK20231292)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(24)3091)+2 种基金the National Natural Science Foundation of China(12464032)the Natural Science Foundation of Jiangxi Province(20232BAB201032)supported by the high performance computing university-level public platform of Jinggangshan University.
文摘Aqueous zinc-ion batteries encounter enormous challenges such as Zn dendrites and parasitic reactions.Separator modification is a highly effective strategy to address these issues.With the advantages of low cost,nontoxicity,biodegradability,good film-forming ability,superior hydro phi licity,and rich functional groups,chitosan is an ideal matrix for constructing separators.However,the presence of positive charges within chitosan in weakly acidic electrolytes is unfavorable for dendrite inhibition.Herein,Schiff base reaction is introduced to modify chitosan matrix,transforming its charge polarity from positive to negative.Additionally,NbN with excellent zincophilicity is coated onto chitosan matrix,forming a Janus separator with low thickness of 19μm and considerably improved mechanical properties.The resultant separator can promote the transport of Zn^(2+)ions while triggering a repulsive shielding effect against anions,therefore dramatically enhancing Zn^(2+)ion transfer number from 0.28 to 0.49.This separator can also facilitate desolvation process,improve exchange current density,restrict two-dimensional Zn^(2+)ion diffusion,and enhance electrochemical kinetics,contributing to significantly inhibited dendrite growth,by-product formation,and hydrogen evolution.Consequently,stable and reversible Zn stripping/plating process is enabled for over 2500 h at 2 mA cm^(-2)and 2 mAh cm^(-2).And great rate capability and excellent cyclability can be achieved for full batteries even under harsh conditions.This work provides new insights into separator design for Zn-based batteries.
文摘The purpose of this research work is to determine the removal efficiency of Cu^(2+)and Pb^(2+)ions using polyvinyl alcohol/neem leaf extract/chitosan(PVA/NLE/CS)composite films as adsorbent materials from an aqueous medium,with respect to pH,contact time,and adsorbent dosage.The synthesized composite material was characterized using Fourier Transform Infrared(FTIR)spectroscopy,thermogravimetric analysis-Derivative Thermogravimetry(TGA-DTG),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy-Energy Dispersive X-ray Spectroscopy(SEM-EDX).The antibacterial activity and swelling response of the material were studied using suitable methodologies.The FTIR study confirmed the interactions among PVA,chitosan,and neem leaf extract.The TGA data reveal the excellent thermal stability of the developed composite films.The SEM micrograph indicates a homogeneous phase morphology with good compatibility among chitosan,the monomer,and the leaf extract.The antibacterial study revealed that the prepared PVA/NLE/CS films exhibit improved antibacterial activity against bacterial growth.It was found that at pH 6.0,the adsorption capacity for both toxic metal ions is maximum,and decreases with a further rise in pH.At this pH,the adsorption capacity of PVA/NLE/CS films increases with a gradual increase in adsorbent dosage,and at a specific pH,the adsorption capacity for Cu^(2+)is greater than that for Pb^(2+).The adsorption efficiency is a function of contact time and was found to be maximal at 180 min.Hence,the developed composite material is effective for the removal of metal ions from wastewater.
基金supported by the Natural Science Foundation of Shandong Province(ZR2021ME124,ZR2023ME033)Science-Education-Industry Integration Innovation Pilot Project of Qilu University of Technology(2024GH09)+2 种基金Innovation Capacity Improvement Project of Small and Medium-Sized Technology-Based Enterprise of Shandong Province(2023TSGC0706,2022TSGC1022)Technological Innovation Projects of Shandong Province(202350700179,202351600213)Science and technology plan project of Shandong Railway Investment Holding Group(TTKJ2023-01)。
文摘It is well known that adsorbent material is the key to determine the CO_(2)adsorption performance.Herein,ZIF-8 derived porous carbon(ZIF-8-C)is anchored into the framework of a novel composite aerogel(ZCPx),which utilizes chitosan(CS)and polyvinyl alcohol(PVA)as raw materials.By controlling the ratio of ZIF-8-C,the developed hierarchical porous structures combine the advantages of micropores,mesopores,and macropores.Besides,the ligand material of ZIF-8-C and the amino group from CS are two sources of the high nitrogen content of ZCPx.The optimized sample ZCP4 shows a high nitrogen content of 6.78%,which can create more active centers and supply basic sites,thereby enhancing the CO_(2)adsorption capacity.Moreover,ZC P4 composite aerogel presents a CO_(2)adsorption capacity of2.26 mmol·g^(-1)(298 K,0.1 MPa)and CO_(2)/N_(2)selectivity(S_(CO_(2))/N_(2))can reach 20.02,and the dynamic breakthrough experiment is performed to confirm the feasibility of CO_(2)/N_(2)actual separation performance,proving that the composite aerogel is potential candidates for CO_(2)adsorption.
基金supported by a grant from the Excellent Young Scholars Cultivation Project of Fujian Medical University Union Hospital,No.2022XH026(to HC)Joint Funds for the Innovation of Science and Technology in Fujian Province,No.2019Y9058(to XL)the Natural Science Foundation of Fujian Province,No.2020J011017(to XL)。
文摘Adipose-derived stem cell,one type of mesenchymal stem cells,is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery.However,its application has been limited by the complexities of the ischemic microenvironment.Hydrogel scaffolds,which are composed of hyaluronic acid and chitosan,exhibit excellent biocompatibility and biodegradability,making them promising candidates as cell carriers.Vascular endothelial growth factor is a crucial regulatory factor for stem cells.Both hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells,thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of stroke.Here,we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem cells.Subsequently,we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemiareperfusion injury.When loaded with adipose-derived stem cells,this vascular endothelial growth factor–loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon morphology.Further in vivo experiments revealed that this vascular endothelial growth factor–loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells,leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery occlusion.It also helped maintain mitochondrial integrity and axonal morphology,greatly improving rat motor function and angiogenesis.Therefore,utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment on transplanted stem cells and enhance the therapeutic effect of stem cells in the context of stroke.
基金supported by the National Natural Science Foundation of China,Nos. 32260196 (to JY), 81860646 (to ZY) and 31860274 (to JY)a grant from Yunnan Department of Science and Technology,Nos. 202101AT070251 (to JY), 202201AS070084 (to ZY), 202301AY070001-239 (to JY), 202101AZ070001-012, and 2019FI016 (to ZY)。
文摘Studies have shown that chitosan protects against neurodegenerative diseases. However, the precise mechanism remains poorly understood. In this study, we administered chitosan intragastrically to an MPTP-induced mouse model of Parkinson's disease and found that it effectively reduced dopamine neuron injury, neurotransmitter dopamine release, and motor symptoms. These neuroprotective effects of chitosan were related to bacterial metabolites, specifically shortchain fatty acids, and chitosan administration altered intestinal microbial diversity and decreased short-chain fatty acid production in the gut. Furthermore, chitosan effectively reduced damage to the intestinal barrier and the blood–brain barrier. Finally, we demonstrated that chitosan improved intestinal barrier function and alleviated inflammation in both the peripheral nervous system and the central nervous system by reducing acetate levels. Based on these findings, we suggest a molecular mechanism by which chitosan decreases inflammation through reducing acetate levels and repairing the intestinal and blood–brain barriers, thereby alleviating symptoms of Parkinson's disease.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Korea government(2021R1F1A1063023)by the Ministry of Education(RS-2023-00270936).
文摘Background:Chitosan oligosaccharide(COS)is the major degradation product of chitosan by enzymatic processes.COS,with complete water solubility,exerts significant biological effects,including anti-cancer activity.We investigated the anti-tumor effects of COS on colorectal cancer as effective therapeutic methods with low side effects are lacking.Methods:COS was obtained from low molecular weight chitosan by an enzymatic method and the anticancer effects were measured by cell viability assay,flow cytometry analysis,Western blotting,and xenograft.Results:COS suppressed the proliferation of SNU-C5 cells compared to other colorectal cancer cells,but higher concentrations were required in the xenograft model.Co-treatment with 5-fluorouracil(5-FU)and COS enhanced the anti-cancer effects of 5-FU in SNU-C5 cells in vitro and in vivo.Flow cytometry revealed that COS induced cell cycle arrest at the G0/G1 phase without 5-FU or at the S and G2/M phases with 5-FU but did not affect cell death pathways.COS increased extracellular signal-regulated protein kinase(ERK)activation with or without 5-FU,whereas 5-FU treatment increased p53 activation.A low-dose of an ERK inhibitor suppressed COS-induced ERK activation and resulted in higher proliferation compared with COS.Conclusions:These results suggest that COS might enhance the anti-cancer effects of 5-FU in SNU-C5 colorectal cancer cells by activating ERK.
基金supported by the National Natural Science Foundation of China,Nos.81941011(to XL),31771053(to HD),31730030(to XL),31971279(to ZY),31900749(to PH),31650001(to XL),31320103903(to XL),31670988(to ZY)the Natural Science Foundation of Beijing,Nos.7222004(to HD)+1 种基金a grant from Ministry of Science and Technology of China,Nos.2017YFC1104002(to ZY),2017YFC1104001(to XL)a grant from Beihang University,No.JKF-YG-22-B001(to FH)。
文摘Attempts have been made to use cell transplantation and biomaterials to promote cell proliferation,differentiation,migration,and survival,as well as angiogenesis,in the context of brain injury.However,whether bioactive materials can repair the damage caused by ischemic stroke by activating endogenous neurogenesis and angiogenesis is still unknown.In this study,we applied chitosan gel loaded with basic fibroblast growth factor to the stroke cavity 7 days after ischemic stroke in rats.The gel slowly released basic fibroblast growth factor,which improved the local microenvironment,activated endogenous neural stem/progenitor cells,and recruited these cells to migrate toward the penumbra and stroke cavity and subsequently differentiate into neurons,while enhancing angiogenesis in the penumbra and stroke cavity and ultimately leading to partial functional recovery.This study revealed the mechanism by which bioactive materials repair ischemic strokes,thus providing a new strategy for the clinical application of bioactive materials in the treatment of ischemic stroke.
基金supported by the National Key Research and Development Program of China(2021YFF0600703).
文摘Chitooligosaccharides(COS)find numerous applications due to their exceptional properties.Enzymatic hydrolysis of chitosan by chitosanase is considered an advantageous route for COS production.Heterologous expression of chitosanase holds significant promise,yet studies using commonly employed Escherichia coli and Pichia pasto-ris strains encounter challenges in subsequent handling and industrial scalability.In this investigation,we opted for using the safe yeast strain Saccharomyces cerevisiae(GRAS),obviating the need for methanol induction,resulting in successful expression.Ultimately,utilizing the GTR-CRISPR editing system,shake flask enzyme activity reached 2 U/ml.The optimal chitosanase activity was achieved at 55℃and pH 5,with favorable stability between 30 and 50°C.Following a 2-h catalytic reaction,the product primarily consisted of chitobiose to chitotetraose,predominantly at the chitotriose position,with a slight increase in chitobiose content observed during the later stages of enzymatic hydrolysis.The results affirm the feasibility of heterologous chitosanase expression through Saccharomyces cerevisiae,underscoring its significant industrial potential.
