Electrospun nanofiber/hydrogel composites combine the excellent biochemical properties of hydrogel with the biomimetic nature of electrospun fibers,and have attracted widespread attention in the last few years.Besides...Electrospun nanofiber/hydrogel composites combine the excellent biochemical properties of hydrogel with the biomimetic nature of electrospun fibers,and have attracted widespread attention in the last few years.Besides,nanofiber/hydrogel composites with tunable mechanical properties can mimic the microstructure of extracellular matrix(ECM)of various tissues and the microenvironment of different cells.These features enable electrospun fiber/hydrogel composites have uniquely advantageous for tissue repair.However,a comprehensive review of electrospun fiber/hydrogel composites as tissue engineering scaffolds is still lacking.Thus,this article systematically reviewed the preparation of electrospun fiber/hydrogel composites and their application in tissue engineering.First,the preparation strategies of electrospun fiber/hydrogel composites are classified and discussed.Second,the application of electrospun fiber/hydrogel-based scaffolds in tissue engineering,involving skin,blood vessel,nerve,bone and other tissue engineering,are summarized.Finally,future research directions for functional electrospun fiber/hydrogel scaffold materials are proposed.展开更多
Electrospun nanofibrous mats represent a new generation of medical textiles with promising applications in heart valve tissue reconstruction. It is important for biomaterials to mimic the biological and mechanical mic...Electrospun nanofibrous mats represent a new generation of medical textiles with promising applications in heart valve tissue reconstruction. It is important for biomaterials to mimic the biological and mechanical microenvironment of native extracellular matrix(ECM). However, the major challenges are still remaining for current biomedical materials, including appropriate mechanical properties,biocompatibility, and hemocompatibility. In the present work, the novel composite nanofibrous mats of poly(p-dioxanone)(PDO) and poly(ester-urethane)ureas(PEUU) are fabricated by electrospinning system. The optimal combination ratio of PDO to PEUU may balance the mechanical properties and cellular compatibility to match the newly formed tissue. In PDO/PEUU composite nanofibrous mats, PEUU can provide the biomimetic elastomeric behavior, and PDO could endow the excellent biocompatibility. In comparison to nanofibrous mat of neat PDO, the composite showed significantly improved mechanical properties, with 5-fold higher initial elongation at break.Furthermore, human umbilical vein endothelial cells(HUVECs) were cultured on the composite to evaluate its ability to rapidly endothelialize as heart valve tissue engineering. The results revealed that PDO/PEUU composite nanofibrous mats could promote cell adhesion and proliferation, especially for the ratio of 60/40. Overall, PDO/PEUU composite nanofibrous mats(60/40) show the excellent mechanical properties, appropriate biocompatibility and hemocompatibility which meet the necessary norm for tissue engineering and may be suitable for potential heart valve tissue reconstruction.展开更多
In this paper, preparation of nano-biphasic calcium phosphate （nBCP）, mechanical behavior and load-bearing of poly （lactide-co-glycolide） （PLGA） and PLGA/nBCP are presented. The nBCP with composition of 63/37 （...In this paper, preparation of nano-biphasic calcium phosphate （nBCP）, mechanical behavior and load-bearing of poly （lactide-co-glycolide） （PLGA） and PLGA/nBCP are presented. The nBCP with composition of 63/37 （w/w） HA/-TCP （hydroxyapatite/fl-tricalcium phosphate） was produced by heating of bovine bone at 700℃. Composite scaffolds were made by using PLGA matrix and 10-50 wt% nBCP powders as reinforcement material. All scaffolds were prepared by thermally induced solid-liquid phase separation （TIPS） at -60~C under 4 Pa （0.04 mbar） vacuum. The results of elastic modulus testing were adjusted with Ishai-Cohen and Narkis models for rigid polymeric matrix and compared to each other. PLGA/nBCP scaffolds with 30 wt% nBCP showed the highest value of yield strength among the scaffolds. In addition, it was found that by increasing the nBCP in scaffolds to 50 wt%, the modulus of elasticity was highly enhanced. However, the optimum value of yield strength was obtained at 30 wt% nBCP, and the agglomeration of reinforcing particles at higher percentages caused a reduction in yield strength. It is clear that the elastic modulus of matrix has the significant role in elastic modulus of scaffolds, as also the size of the filler particles in the matrix.展开更多
In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, ...In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.展开更多
The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/...The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.展开更多
In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical pr...In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical properties of the scaffolds were controlled by varying solvent ratios, quenching temperatures and carbon nanotubes concentration. In vitro cell culture of Sprague-Dawley rat’s osteoblasts was used to evaluate the phenotype expression of cells in the scaffolds. The presence of MWCNT in a chitosan matrix improving its mechanical properties and sustain osteoblast growth and differentiation that represent a potential application of the Chitosan/MWCNT as biomaterial for bone tissue engineering.展开更多
Aim: Periodontitis is caused by chronic gingival inflammation and affects a large population in the world. Although guided tissue regeneration (GTR) therapy has been proven to be an effective treatment, the deficiency...Aim: Periodontitis is caused by chronic gingival inflammation and affects a large population in the world. Although guided tissue regeneration (GTR) therapy has been proven to be an effective treatment, the deficiency in the symmetrical design of all the GTR membrane in the market leaves large space for improvement. Therefore, we designed a novel asymmetrical bi-layer PLA/gelatin composite membrane for treating periodontitis. Methods: The PLA side was fabricated by electrospinning with metronidazole (MNA) pre-mixed with the PLA solution. The gelatin side containing bioglass (BG) 45S5 was fabricated with freeze-drying process and cross-linked with PLA membrane. The bio-compatibility of the membrane was evaluated in vitro using NIH3T3 cells. The releasing of MNA was measured by spectrophotometer. The bioactivity of the membrane was evaluated by hydroxyapatite (HA) deposit and determined by FTIR spectrometer. The ionic concentration of Ca2+ and was measured by ICPOES. The expression of the osteogenesis makers was determined by qRT-PCR. Results: The bi-layer PLA/gelatin composite membrane is biocompatible and bioactive. The releasing of MNA can rapidly reach the anti-bacterial effective concentration. Interestingly, the incorporation of MNA modulated the degradation rate of PLA scaffold to meet the requirement of tissue regeneration. Meanwhile, the embedding of the BG powder in the gelatin porous layer provided a favorable Ca2+ and ion environment for the regeneration of the alveolar bone tissue. Conclusions: Taken together, this bi-layer GTR membrane is closer to the physiological structure of the periodontal. The addition of MNA and BG makes it more powerful in treating periodontitis. Moreover, this research provides an example of biomimetic design in fabricating biomaterial for clinical applications.展开更多
Novel bioactive injectable composites based on biopolymeric hydrogels reinforced with insulin-functionalized silica particles were synthesized.The insulin(INS)was immobilized on the surface of amine-modifed silica par...Novel bioactive injectable composites based on biopolymeric hydrogels reinforced with insulin-functionalized silica particles were synthesized.The insulin(INS)was immobilized on the surface of amine-modifed silica particles employing covalent attachment by EDC/NHS chemistry and via electrostatic interaction.The resulting formulations were examined for the morphology(SEM),chemical composition(FTIR,XPS)as well as protein content.To facilitate the injectability and support the bone regeneration,developed particles were dispersed in biopolymeric sol composed of collagen,chitosan and lysinemodifed hyaluronic acid and crosslinked with genipin.By means of rheological study,the sol-gel in situ transition of obtained systems was verifed.It was found in vitro study that MG-63 cells cultured on the developed composites exhibit signifcantly higher alkaline phosphatase(ALP)activity,compared to the pristine hydrogel.Furthermore,the biomineralization ability in the simulated body fluid(SBF)model was also demonstrated.Our fndings suggest that proposed herein novel hydrogel-based composites might be the promising formulation for regeneration of bone defects,especially as a less-cost effective support/alternative for BMP-2 systems.展开更多
BACKGROUND Composite tumors are neoplasms comprising two distinct,yet intermingling,cell populations.This paper reports a rare phenomenon where early gastric signet-ring cell carcinoma(SRCC)and gastric mucosa-associat...BACKGROUND Composite tumors are neoplasms comprising two distinct,yet intermingling,cell populations.This paper reports a rare phenomenon where early gastric signet-ring cell carcinoma(SRCC)and gastric mucosa-associated lymphoid tissue(MALT)lymphoma coexist within the same lesion.CASE SUMMARY A 40-year-old woman presented to the West China Hospital for examination,which revealed a whitish,shallow,and uneven mucosal lesion in the stomach.The lesion was diagnosed as a poorly differentiated adenocarcinoma,including SRCC with atypical lymphoid hyperplasia associated with Helicobacter pylori infection,based on histopathological examination of the biopsy specimen.The lesion was excised using segmental gastrectomy.However,histological exami-nation of the surgical specimen confirmed that it was a poorly differentiated gastric adenocarcinoma with features of SRCC and MALT lymphoma.These two entities were stage I and coexisted in the same lesion.CONCLUSION It is uncommon for gastric SRCC and MALT lymphoma to coexist without distinct borders.Surgical resection is effective for these lesions.展开更多
Tree knots are generally considered defects in wood,but how the surrounding structures of the defects affects strength of wood has not been studied.Here the mechanical properties of static compression and hole bearing...Tree knots are generally considered defects in wood,but how the surrounding structures of the defects affects strength of wood has not been studied.Here the mechanical properties of static compression and hole bearing tests were designed for encased knots and intergrown knots,and the strengthening mechanism of streamline tissue and connecting interface was analyzed by finite element modeling.And the two reinforced structures were applied to composite structural holes and connecting holes,which significantly improved open hole compressive strength and hole bearing strength.And the finite element models for two kinds of composite hole were created to analyze how the stress field around the reinforced structure strengthens the composite.Both the experimental results and the finite analysis results show that the streamline structure could effectively improve the compressive properties of composite structural holes,and the connecting interface provided a stable constraint for giving full play to the hole bearing properties of stronger materials.These two structures will provide reference for the structural design of lightweight composites.展开更多
Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limi...Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limited due to its poor mechanical property and structural diversity.Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties.Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel,but also expand the functionality of hydrogel.Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods.In this review,we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities.In addition,further development and application prospects of the micelle-hydrogels composites have also been addressed.展开更多
Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely use...Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely used in food,textile and paper industries;and to a lesser extent in biomedical applications as biomaterial to promote wound healing and tissue regeneration.This is evident from the rising use of alginate-based dressing for heavily exuding wound and their mass availability in the market nowadays.However,alginate also has limitation.When in contact with physiological environment,alginate could gelate into softer structure,consequently limits its potential in the soft tissue regeneration and becomes inappropriate for the usage related to load bearing body parts.To cater this problem,wide range of materials have been added to alginate structure,producing sturdy composite materials.For instance,the incorporation of adhesive peptide and natural polymer or synthetic polymer to alginate moieties creates an improved composite material,which not only possesses better mechanical properties compared to native alginate,but also grants additional healing capability and promote better tissue regeneration.In addition,drug release kinetic and cell viability can be further improved when alginate composite is used as encapsulating agent.In this review,preparation of alginate and alginate composite in various forms(fibre,bead,hydrogel,and 3D-printed matrices)used for biomedical application is described first,followed by the discussion of latest trend related to alginate composite utilization in wound dressing,drug delivery,and tissue engineering applications.展开更多
In an effort to develop biomaterials to meet guided tissue regeneration （GTR） standards for periodontal tissue recovery, a homogeneous and transparent chitosan （CS）/hydroxyapatite （HA） membrane with potential ap...In an effort to develop biomaterials to meet guided tissue regeneration （GTR） standards for periodontal tissue recovery, a homogeneous and transparent chitosan （CS）/hydroxyapatite （HA） membrane with potential applications as GTR barrier in periodontal therapy has been prepared via in situ compositing. The membrane has been designed to have a smoothrough asymmetric structure that meets the demand for GTR. Component and morphology of the membrane are characterized by XRD and SEM. It can be indicated that HA was in situ synthesized uniformly in the CS membrane. Mechanical experiments of the membranes with various HA contents show that their tensile strengths are adequate for periodontal therapy. Biological properties of the membrane have been performed by cell toxicity assays, hemolysis tests and animal experiments. Results indicate that the membrane has good biocompatibility and inductive effect for cell growth. Therefore this membrane can be potentially applied as GTR barrier membrane for periodontal tissue regeneration.展开更多
A new facile route for preparation of β-TCP/PLLA composites is reported in this letter. SEM images display that β-TCP particles with average diameter of 400 nm were well bonded and distributed within the pore walls ...A new facile route for preparation of β-TCP/PLLA composites is reported in this letter. SEM images display that β-TCP particles with average diameter of 400 nm were well bonded and distributed within the pore walls of the PLLA scaffolds. The mixture of the novel complex and human dental pulp cells was transplanted subcutaneously into the dorsal surface of a nude mouse. Two months later histological examination showed that new collagen and new dentin formed. The results revealed that the new nano β-TCP/PLLA composite combined with human pulp cells could induce dentin formation offering a new way to dental tissue engineering.展开更多
Background High-grain(HG)diets affect lipid metabolism in the liver and mammary tissue of dairy cows,but its effects on muscle and adipose tissue have not been wide evaluated.Thus,the aim of this study is to clarify t...Background High-grain(HG)diets affect lipid metabolism in the liver and mammary tissue of dairy cows,but its effects on muscle and adipose tissue have not been wide evaluated.Thus,the aim of this study is to clarify this issue.Methods Twelve Holstein cows were randomly divided into two groups:conventional diet group(CON,n=6)and the HG diet group(n=6).On day 7 of week 4,rumen fluid was sampled to measure pH,milk was sampled to meas-ure components,and blood was sampled to measure biochemical parameters and fatty acid composition.After the experiment,cows were slaughtered to collect muscle and adipose tissue for fatty acid composition and transcriptome analysis.Results HG feeding decreased the ruminal pH,milk’s fat content and long-chain fatty acid proportion(P<0.05)and increased the proportion of short-and medium-chain fatty acids in the milk(P<0.05)as compared with CON diets.The concentrations of blood cholesterol,low-density lipoprotein,and polyunsaturated fatty acids in the HG cows were lower than those in CON cows(P<0.05).In muscle tissue,HG feeding tended to increase the triacylglycerol(TG)concentration(P<0.10).Transcriptome analysis revealed changes in the biosynthesis of the unsaturated fatty acids pathway,the regulation of lipolysis in the adipocytes pathway,and the PPAR signalling pathway.In adipose tissue,HG feeding increased the concentration of TG and decreased the concentration of C18:1 cis9(P<0.05).At the transcrip-tome level,the fatty acid biosynthesis pathway,linoleic acid metabolism pathway,and PPAR signalling pathway were activated.Conclusion HG feeding leads to subacute rumen acidosis and a decreased milk fat content.The fatty acid profiles in the milk and plasma of dairy cows were changed by HG feeding.In muscle and adipose tissue,HG feeding increased TG concentration and up-regulated the expression of genes related to adipogenesis,while down-regulated the expression of genes related to lipid transport.These results complement our knowledge of the fatty acid composi-tion of muscle and adipose tissue in dairy cows and expand our understanding of the mechanisms by which HG diets affect lipid metabolism in muscle and adipose tissue.展开更多
In this study, poly（L-lactic acid）/ammonium persulfate doped-polypyrrole composite fibrous scaffolds with moderate conductivity were produced by combining electrospinning with in situ polymerization. PC12 cells were...In this study, poly（L-lactic acid）/ammonium persulfate doped-polypyrrole composite fibrous scaffolds with moderate conductivity were produced by combining electrospinning with in situ polymerization. PC12 cells were cultured on these fibrous scaffolds and their growth following electrical stimulation （0-20.0 μA stimulus intensity, for 1-4 days） was observed using inverted light microscopy, and scanning electron microscopy coupled with the MTT cell viability test. The results demonstrated that the poly（L-lactic acid）/ammonium persulfate doped-polypyrrole fibrous scaffold was a dual multi-porous micro/nano fibrous scaffold. An electrical stimulation with a current intensity 5.0- 10.0 μAfor about 2 days enhanced neuronal growth and neurite outgrowth, while a high current intensity （over 15.0 μA） suppressed them. These results indicate that electrical stimulation with a moderate current intensity for an optimum time frame can promote neuronal growth and neurite outgrowth in an intensity- and time-dependent manner.展开更多
A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds....A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection micro-porous structure is obtained. Bioeompatibility test of the scaffolds shows that PVA-GAG-COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA-GAG-COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.展开更多
Bigeye tuna is a protein-rich fish that is susceptible to spoilage during cold storage,however,there is limited information on untargeted metabolomic profiling of bigeye tuna concerning spoilage-associated enzymes and...Bigeye tuna is a protein-rich fish that is susceptible to spoilage during cold storage,however,there is limited information on untargeted metabolomic profiling of bigeye tuna concerning spoilage-associated enzymes and metabolites.This study aimed to investigate how cold storage affects enzyme activities,nutrient composition,tissue microstructures and spoilage metabolites of bigeye tuna.The activities of cathepsins B,H,L increased,while Na^(+)/K^(+)-ATPase and Mg^(2+)-ATPase decreased,α-glucosidase,lipase and lipoxygenase first increased and then decreased during cold storage,suggesting that proteins undergo degradation and ATP metabolism occurs at a faster rate during cold storage.Nutrient composition(moisture and lipid content),total amino acids decreased,suggesting that the nutritional value of bigeye tuna was reduced.Besides,a logistic regression equation has been established as a food analysis tool and assesses the dynamics and correlation of the enzyme of bigeye tuna during cold storage.Based on untargeted metabolomic profiling analysis,a total of 524 metabolites were identified in the bigeye tuna contained several spoilage metabolites involved in lipid metabolism(glycerophosphocholine and choline phosphate),amino acid metabolism(L-histidine,5-deoxy-5′-(methylthio)adenosine,5-methylthioadenosine),carbohydrate metabolism(D-gluconic acid,α-D-fructose 1,6-bisphosphate,D-glyceraldehyde 3-phosphate).The results of tissue microstructures of tuna showed a looser network and visible deterioration of tissue fiber during cold storage.Therefore,metabolomic analysis and tissue microstructures provide insight into the spoilage mechanism investigations on bigeye tuna during cold storage.展开更多
基金supported in part by the Key Research and Development Program of Shaanxi(No.2022SF-200)the Fund of Jiangsu Key Laboratory of Advanced Functional Polymers Design and Application in Soochow University(No.KJS2007).
文摘Electrospun nanofiber/hydrogel composites combine the excellent biochemical properties of hydrogel with the biomimetic nature of electrospun fibers,and have attracted widespread attention in the last few years.Besides,nanofiber/hydrogel composites with tunable mechanical properties can mimic the microstructure of extracellular matrix(ECM)of various tissues and the microenvironment of different cells.These features enable electrospun fiber/hydrogel composites have uniquely advantageous for tissue repair.However,a comprehensive review of electrospun fiber/hydrogel composites as tissue engineering scaffolds is still lacking.Thus,this article systematically reviewed the preparation of electrospun fiber/hydrogel composites and their application in tissue engineering.First,the preparation strategies of electrospun fiber/hydrogel composites are classified and discussed.Second,the application of electrospun fiber/hydrogel-based scaffolds in tissue engineering,involving skin,blood vessel,nerve,bone and other tissue engineering,are summarized.Finally,future research directions for functional electrospun fiber/hydrogel scaffold materials are proposed.
基金financially supported by the Capacity Building Project of Some Local Colleges and Universities in Shanghai (No. 17030501200)the National Natural Science Foundation of China (No. 81501595)+2 种基金Youth Foundation of Zhongshan Hospital (No. 2015ZSQN09)Talent Training Program Foundation for the Excellent Youth Supported by Zhongshan Hospital (No. 2017ZSYQ24)Innovation Fund of Zhongshan Hospital (No. 2017ZSCX05)
文摘Electrospun nanofibrous mats represent a new generation of medical textiles with promising applications in heart valve tissue reconstruction. It is important for biomaterials to mimic the biological and mechanical microenvironment of native extracellular matrix(ECM). However, the major challenges are still remaining for current biomedical materials, including appropriate mechanical properties,biocompatibility, and hemocompatibility. In the present work, the novel composite nanofibrous mats of poly(p-dioxanone)(PDO) and poly(ester-urethane)ureas(PEUU) are fabricated by electrospinning system. The optimal combination ratio of PDO to PEUU may balance the mechanical properties and cellular compatibility to match the newly formed tissue. In PDO/PEUU composite nanofibrous mats, PEUU can provide the biomimetic elastomeric behavior, and PDO could endow the excellent biocompatibility. In comparison to nanofibrous mat of neat PDO, the composite showed significantly improved mechanical properties, with 5-fold higher initial elongation at break.Furthermore, human umbilical vein endothelial cells(HUVECs) were cultured on the composite to evaluate its ability to rapidly endothelialize as heart valve tissue engineering. The results revealed that PDO/PEUU composite nanofibrous mats could promote cell adhesion and proliferation, especially for the ratio of 60/40. Overall, PDO/PEUU composite nanofibrous mats(60/40) show the excellent mechanical properties, appropriate biocompatibility and hemocompatibility which meet the necessary norm for tissue engineering and may be suitable for potential heart valve tissue reconstruction.
基金supported by Isfahan University of Technology and Ministry of Sciences, Research & Technology in Iran and Materials Science & Engineering School of Nanyang Technological University in Singapore
文摘In this paper, preparation of nano-biphasic calcium phosphate （nBCP）, mechanical behavior and load-bearing of poly （lactide-co-glycolide） （PLGA） and PLGA/nBCP are presented. The nBCP with composition of 63/37 （w/w） HA/-TCP （hydroxyapatite/fl-tricalcium phosphate） was produced by heating of bovine bone at 700℃. Composite scaffolds were made by using PLGA matrix and 10-50 wt% nBCP powders as reinforcement material. All scaffolds were prepared by thermally induced solid-liquid phase separation （TIPS） at -60~C under 4 Pa （0.04 mbar） vacuum. The results of elastic modulus testing were adjusted with Ishai-Cohen and Narkis models for rigid polymeric matrix and compared to each other. PLGA/nBCP scaffolds with 30 wt% nBCP showed the highest value of yield strength among the scaffolds. In addition, it was found that by increasing the nBCP in scaffolds to 50 wt%, the modulus of elasticity was highly enhanced. However, the optimum value of yield strength was obtained at 30 wt% nBCP, and the agglomeration of reinforcing particles at higher percentages caused a reduction in yield strength. It is clear that the elastic modulus of matrix has the significant role in elastic modulus of scaffolds, as also the size of the filler particles in the matrix.
文摘In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.
基金National Natural Science Foundations of China(Nos.31271028,31570984)Innovation Program of Shanghai Municipal Education Commission,China(No.13ZZ051)+2 种基金International Cooperation Fund of the Science and Technology Commission of Shanghai Municipality,China(No.15540723400)Open Foundation of State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LK1416)“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.
文摘In this work the influence of multiwalled carbon nanotubes (MWCNT) on mechanical properties was evaluated also the osteoinduction mechanism in Chitosan/MWCNT composite is reported. The morphology and the mechanical properties of the scaffolds were controlled by varying solvent ratios, quenching temperatures and carbon nanotubes concentration. In vitro cell culture of Sprague-Dawley rat’s osteoblasts was used to evaluate the phenotype expression of cells in the scaffolds. The presence of MWCNT in a chitosan matrix improving its mechanical properties and sustain osteoblast growth and differentiation that represent a potential application of the Chitosan/MWCNT as biomaterial for bone tissue engineering.
文摘Aim: Periodontitis is caused by chronic gingival inflammation and affects a large population in the world. Although guided tissue regeneration (GTR) therapy has been proven to be an effective treatment, the deficiency in the symmetrical design of all the GTR membrane in the market leaves large space for improvement. Therefore, we designed a novel asymmetrical bi-layer PLA/gelatin composite membrane for treating periodontitis. Methods: The PLA side was fabricated by electrospinning with metronidazole (MNA) pre-mixed with the PLA solution. The gelatin side containing bioglass (BG) 45S5 was fabricated with freeze-drying process and cross-linked with PLA membrane. The bio-compatibility of the membrane was evaluated in vitro using NIH3T3 cells. The releasing of MNA was measured by spectrophotometer. The bioactivity of the membrane was evaluated by hydroxyapatite (HA) deposit and determined by FTIR spectrometer. The ionic concentration of Ca2+ and was measured by ICPOES. The expression of the osteogenesis makers was determined by qRT-PCR. Results: The bi-layer PLA/gelatin composite membrane is biocompatible and bioactive. The releasing of MNA can rapidly reach the anti-bacterial effective concentration. Interestingly, the incorporation of MNA modulated the degradation rate of PLA scaffold to meet the requirement of tissue regeneration. Meanwhile, the embedding of the BG powder in the gelatin porous layer provided a favorable Ca2+ and ion environment for the regeneration of the alveolar bone tissue. Conclusions: Taken together, this bi-layer GTR membrane is closer to the physiological structure of the periodontal. The addition of MNA and BG makes it more powerful in treating periodontitis. Moreover, this research provides an example of biomimetic design in fabricating biomaterial for clinical applications.
基金the financial support of National Science Centre,Poland,Grant 2016/21/D/ST5/01635。
文摘Novel bioactive injectable composites based on biopolymeric hydrogels reinforced with insulin-functionalized silica particles were synthesized.The insulin(INS)was immobilized on the surface of amine-modifed silica particles employing covalent attachment by EDC/NHS chemistry and via electrostatic interaction.The resulting formulations were examined for the morphology(SEM),chemical composition(FTIR,XPS)as well as protein content.To facilitate the injectability and support the bone regeneration,developed particles were dispersed in biopolymeric sol composed of collagen,chitosan and lysinemodifed hyaluronic acid and crosslinked with genipin.By means of rheological study,the sol-gel in situ transition of obtained systems was verifed.It was found in vitro study that MG-63 cells cultured on the developed composites exhibit signifcantly higher alkaline phosphatase(ALP)activity,compared to the pristine hydrogel.Furthermore,the biomineralization ability in the simulated body fluid(SBF)model was also demonstrated.Our fndings suggest that proposed herein novel hydrogel-based composites might be the promising formulation for regeneration of bone defects,especially as a less-cost effective support/alternative for BMP-2 systems.
基金Supported by National Natural Science Foundation of China,No.82173253.
文摘BACKGROUND Composite tumors are neoplasms comprising two distinct,yet intermingling,cell populations.This paper reports a rare phenomenon where early gastric signet-ring cell carcinoma(SRCC)and gastric mucosa-associated lymphoid tissue(MALT)lymphoma coexist within the same lesion.CASE SUMMARY A 40-year-old woman presented to the West China Hospital for examination,which revealed a whitish,shallow,and uneven mucosal lesion in the stomach.The lesion was diagnosed as a poorly differentiated adenocarcinoma,including SRCC with atypical lymphoid hyperplasia associated with Helicobacter pylori infection,based on histopathological examination of the biopsy specimen.The lesion was excised using segmental gastrectomy.However,histological exami-nation of the surgical specimen confirmed that it was a poorly differentiated gastric adenocarcinoma with features of SRCC and MALT lymphoma.These two entities were stage I and coexisted in the same lesion.CONCLUSION It is uncommon for gastric SRCC and MALT lymphoma to coexist without distinct borders.Surgical resection is effective for these lesions.
文摘Tree knots are generally considered defects in wood,but how the surrounding structures of the defects affects strength of wood has not been studied.Here the mechanical properties of static compression and hole bearing tests were designed for encased knots and intergrown knots,and the strengthening mechanism of streamline tissue and connecting interface was analyzed by finite element modeling.And the two reinforced structures were applied to composite structural holes and connecting holes,which significantly improved open hole compressive strength and hole bearing strength.And the finite element models for two kinds of composite hole were created to analyze how the stress field around the reinforced structure strengthens the composite.Both the experimental results and the finite analysis results show that the streamline structure could effectively improve the compressive properties of composite structural holes,and the connecting interface provided a stable constraint for giving full play to the hole bearing properties of stronger materials.These two structures will provide reference for the structural design of lightweight composites.
基金the Natural Science Basic Research Program of Shaanxi Province(No.2023-JC-YB-101)the Basic Science Research Program of Shaanxi Basic Sciences Institute(Chemistry,Biology)(No.22JHQ079)National Natural Science Foundation of China(No.82272150).
文摘Designing advanced hydrogels with controlled mechanical properties,drug delivery manner and multifunctional properties will be beneficial for biomedical applications.However,the further development of hydrogel is limited due to its poor mechanical property and structural diversity.Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties.Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel,but also expand the functionality of hydrogel.Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods.In this review,we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities.In addition,further development and application prospects of the micelle-hydrogels composites have also been addressed.
基金The authors acknowledge the financial support received from Ministry of Education Malaysia(FRGS/1/2018/TK05/UIAM/03/3).Writing on fibre preparation,chitin,and chitosan are directly related to the said grant.
文摘Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp.and Pseudomonas sp.Owing to alginate gel forming capability,it is widely used in food,textile and paper industries;and to a lesser extent in biomedical applications as biomaterial to promote wound healing and tissue regeneration.This is evident from the rising use of alginate-based dressing for heavily exuding wound and their mass availability in the market nowadays.However,alginate also has limitation.When in contact with physiological environment,alginate could gelate into softer structure,consequently limits its potential in the soft tissue regeneration and becomes inappropriate for the usage related to load bearing body parts.To cater this problem,wide range of materials have been added to alginate structure,producing sturdy composite materials.For instance,the incorporation of adhesive peptide and natural polymer or synthetic polymer to alginate moieties creates an improved composite material,which not only possesses better mechanical properties compared to native alginate,but also grants additional healing capability and promote better tissue regeneration.In addition,drug release kinetic and cell viability can be further improved when alginate composite is used as encapsulating agent.In this review,preparation of alginate and alginate composite in various forms(fibre,bead,hydrogel,and 3D-printed matrices)used for biomedical application is described first,followed by the discussion of latest trend related to alginate composite utilization in wound dressing,drug delivery,and tissue engineering applications.
基金supported by the National Natural Science Foundation of China(No.50773070)the Key Basic Research Development Plan(Project 973) of China(No.2005CB623902)+1 种基金Grand Science and Technology Special Project of Zhejiang Province(No.2008C11087)Science and Technology Project of Zhejiang Province(No.2006C33067)
文摘In an effort to develop biomaterials to meet guided tissue regeneration （GTR） standards for periodontal tissue recovery, a homogeneous and transparent chitosan （CS）/hydroxyapatite （HA） membrane with potential applications as GTR barrier in periodontal therapy has been prepared via in situ compositing. The membrane has been designed to have a smoothrough asymmetric structure that meets the demand for GTR. Component and morphology of the membrane are characterized by XRD and SEM. It can be indicated that HA was in situ synthesized uniformly in the CS membrane. Mechanical experiments of the membranes with various HA contents show that their tensile strengths are adequate for periodontal therapy. Biological properties of the membrane have been performed by cell toxicity assays, hemolysis tests and animal experiments. Results indicate that the membrane has good biocompatibility and inductive effect for cell growth. Therefore this membrane can be potentially applied as GTR barrier membrane for periodontal tissue regeneration.
基金We gratefully acknowledge the support of this research work by National High Technology Research and Development Program of China （No. 2003AA302220, 2004AA304G50）the National Natural Science Foundation of China （No. 30471907）.
文摘A new facile route for preparation of β-TCP/PLLA composites is reported in this letter. SEM images display that β-TCP particles with average diameter of 400 nm were well bonded and distributed within the pore walls of the PLLA scaffolds. The mixture of the novel complex and human dental pulp cells was transplanted subcutaneously into the dorsal surface of a nude mouse. Two months later histological examination showed that new collagen and new dentin formed. The results revealed that the new nano β-TCP/PLLA composite combined with human pulp cells could induce dentin formation offering a new way to dental tissue engineering.
基金funded by the National Key R&D Program of China(2022YFD1301001)the Natural Science Foundation of China(32072755).
文摘Background High-grain(HG)diets affect lipid metabolism in the liver and mammary tissue of dairy cows,but its effects on muscle and adipose tissue have not been wide evaluated.Thus,the aim of this study is to clarify this issue.Methods Twelve Holstein cows were randomly divided into two groups:conventional diet group(CON,n=6)and the HG diet group(n=6).On day 7 of week 4,rumen fluid was sampled to measure pH,milk was sampled to meas-ure components,and blood was sampled to measure biochemical parameters and fatty acid composition.After the experiment,cows were slaughtered to collect muscle and adipose tissue for fatty acid composition and transcriptome analysis.Results HG feeding decreased the ruminal pH,milk’s fat content and long-chain fatty acid proportion(P<0.05)and increased the proportion of short-and medium-chain fatty acids in the milk(P<0.05)as compared with CON diets.The concentrations of blood cholesterol,low-density lipoprotein,and polyunsaturated fatty acids in the HG cows were lower than those in CON cows(P<0.05).In muscle tissue,HG feeding tended to increase the triacylglycerol(TG)concentration(P<0.10).Transcriptome analysis revealed changes in the biosynthesis of the unsaturated fatty acids pathway,the regulation of lipolysis in the adipocytes pathway,and the PPAR signalling pathway.In adipose tissue,HG feeding increased the concentration of TG and decreased the concentration of C18:1 cis9(P<0.05).At the transcrip-tome level,the fatty acid biosynthesis pathway,linoleic acid metabolism pathway,and PPAR signalling pathway were activated.Conclusion HG feeding leads to subacute rumen acidosis and a decreased milk fat content.The fatty acid profiles in the milk and plasma of dairy cows were changed by HG feeding.In muscle and adipose tissue,HG feeding increased TG concentration and up-regulated the expression of genes related to adipogenesis,while down-regulated the expression of genes related to lipid transport.These results complement our knowledge of the fatty acid composi-tion of muscle and adipose tissue in dairy cows and expand our understanding of the mechanisms by which HG diets affect lipid metabolism in muscle and adipose tissue.
基金supported by the National Natural Science Foundation of China,No.51073072the Natural Science Foundation of Zhejiang Province in China,No.Y4100745+1 种基金the Key Laboratory Open Foundation of Advanced Textile Materials&Manufacturing Technology of Zhejiang Sci-Tech University from Ministry of Education of China,No.2009007the Science and Technology Commission of Jiaxing Municipality Program,No.2010AY1089
文摘In this study, poly（L-lactic acid）/ammonium persulfate doped-polypyrrole composite fibrous scaffolds with moderate conductivity were produced by combining electrospinning with in situ polymerization. PC12 cells were cultured on these fibrous scaffolds and their growth following electrical stimulation （0-20.0 μA stimulus intensity, for 1-4 days） was observed using inverted light microscopy, and scanning electron microscopy coupled with the MTT cell viability test. The results demonstrated that the poly（L-lactic acid）/ammonium persulfate doped-polypyrrole fibrous scaffold was a dual multi-porous micro/nano fibrous scaffold. An electrical stimulation with a current intensity 5.0- 10.0 μAfor about 2 days enhanced neuronal growth and neurite outgrowth, while a high current intensity （over 15.0 μA） suppressed them. These results indicate that electrical stimulation with a moderate current intensity for an optimum time frame can promote neuronal growth and neurite outgrowth in an intensity- and time-dependent manner.
基金863 Program grant number: 2077AA09Z436+1 种基金Guangdong Province '211' Fund for Biomaterials and Tissue Engineering grantnumber: 50621030
文摘A PVA-GAG-COL composite scaffold is fabricated by polyvinyl alcohol （PVA）, glyeosaminoglycan （GAG） and collagen （COL）. Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection micro-porous structure is obtained. Bioeompatibility test of the scaffolds shows that PVA-GAG-COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA-GAG-COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.
基金supported by the Shanghai Sailing Program(22YF1416300)Youth Fund Project of National Natural Science Foundation of China(32202117)+1 种基金National Key Research and Development Program of China(2022YFD2100104)the China Agriculture Research System(CARS-47).
文摘Bigeye tuna is a protein-rich fish that is susceptible to spoilage during cold storage,however,there is limited information on untargeted metabolomic profiling of bigeye tuna concerning spoilage-associated enzymes and metabolites.This study aimed to investigate how cold storage affects enzyme activities,nutrient composition,tissue microstructures and spoilage metabolites of bigeye tuna.The activities of cathepsins B,H,L increased,while Na^(+)/K^(+)-ATPase and Mg^(2+)-ATPase decreased,α-glucosidase,lipase and lipoxygenase first increased and then decreased during cold storage,suggesting that proteins undergo degradation and ATP metabolism occurs at a faster rate during cold storage.Nutrient composition(moisture and lipid content),total amino acids decreased,suggesting that the nutritional value of bigeye tuna was reduced.Besides,a logistic regression equation has been established as a food analysis tool and assesses the dynamics and correlation of the enzyme of bigeye tuna during cold storage.Based on untargeted metabolomic profiling analysis,a total of 524 metabolites were identified in the bigeye tuna contained several spoilage metabolites involved in lipid metabolism(glycerophosphocholine and choline phosphate),amino acid metabolism(L-histidine,5-deoxy-5′-(methylthio)adenosine,5-methylthioadenosine),carbohydrate metabolism(D-gluconic acid,α-D-fructose 1,6-bisphosphate,D-glyceraldehyde 3-phosphate).The results of tissue microstructures of tuna showed a looser network and visible deterioration of tissue fiber during cold storage.Therefore,metabolomic analysis and tissue microstructures provide insight into the spoilage mechanism investigations on bigeye tuna during cold storage.
