Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability propertie...Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability properties.It is well known that PBAT suffers a series of natural weathering,mechanical wear,hydrolysis,photochemical transformation,and other abiotic degradation processes before being biodegraded.Therefore,it is particularly important to understand the role of abiotic degradation in the life cycle of PBAT.Since the abiotic degradation of PBAT has not been systematically summarized,this review aims to summarize the mechanisms and main factors of the three major abiotic degradation pathways(hydrolysis,photochemical transformation,and thermochemical degradation)of PBAT.It was found that all of them preferentially destroy the chemical bonds with higher energy(especially C-O and C=O)of PBAT,which eventually leads to the shortening of the polymer chain and then leads to reduction in molecular weight.The main factors affecting these abiotic degradations are closely related to the energy or PBAT structure.These findings provide important theoretical and practical guidance for identifying effective methods for PBAT waste management and proposing advanced schemes to regulate the degradation rate of PBAT.展开更多
In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were inve...In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.展开更多
Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification ...Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification and good biocompatibility.However,as a result of the poor biodegradability of MsNs,their biomedical applications are limited.To break the bottleneck of limited biomedical applications of MSNs,more and more researchers tend to design biodegradable MSNs(b-MSNs)nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers.In this review,we focused on sum-marizing strategies to improve the degradability of MsNs and innovatively proposed a series of advan-tages of b-MsNs,including controlled cargo release behavior,multifunctional frameworks,nano-catalysis,bio-imaging capabilities and enhanced therapeutic effects.Based on these advantages,we have inno-vatively summarized the applications of b-MsNs for enhanced tumor theranostics,including enhanced chemotherapy,delivery of nanosensitizers,gas molecules and biomacromolecules,initiation of immune response,synergistic therapies and image-guided tumor diagnostics.Finally,the challenges and further clinical translation potential of nanosystems based on b-MsNs are fully discussed and prospected.We believe that such b-MsNs delivery carriers will provide a timely reference for further applications in tu-mor theranostics.展开更多
Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible...Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible part of crops.This forces bioplastics to competewith food production because the crops that produce bioplastics can also be used for human nutrition.That is why the article’s main focus is on creating bioplastics using renewable,non-food raw materials(cellulose,lignin,etc.).Eco-friendly composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)with reed and hemp waste as a filler.The physic-chemical features of the structure and surface,as well as the technological characteristics of reed and hemp waste as the organic fillers for renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid),were studied.Theeffect of the fractional composition analysis,morphology,and nature of reed and hempwaste on the quality of the design of eco-friendly biodegradable composites and their ability to disperse in the matrix of renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch and poly(lactic acid)was carried out.The influence of different content and morphology of reed and hemp waste on the composite characteristics was investigated.It is shown that the most optimal direction for obtaining strong eco-friendly biodegradable composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)is associated with the use of waste reed stalks,with its optimal content at the level of 50 wt.%.展开更多
This study aimed to develop and characterize biodegradable packaging film from blends of two natural polysaccharides,i.e.,agar and glucomannan.The glucomannan used was derived from the specific tuber plant Amorphophal...This study aimed to develop and characterize biodegradable packaging film from blends of two natural polysaccharides,i.e.,agar and glucomannan.The glucomannan used was derived from the specific tuber plant Amorphophallus oncophyllus(locally known as“porang”),which grows abundantly in Indonesian forests and remains underutilized.Various ratios of agar and porang-glucomannan(PG)proportions were formulated to produce a food packaging film,which was subsequently tested for its mechanical,physical,chemical,and thermal properties.The results showed that the inclusion of PG to the film formulations notably enhanced the stretchability of agar films,achieving maximum a twofold increase,while concurrently reducing their water resistance such as increased water solubility and water swelling for up to 125%and 105%,respectively.The mechanical and thermal properties,as well as the water vapor permeability of the resulting film,were significantly affected by the polymer matrix structure formed by the varying proportions of the two biopolymers.The enhancement of these properties was associated with a more solid/compact film structure,as corroborated by cross-sectional images obtained through SEM analysis.The study’s findings suggest that utilizing agar and porang biomass has significant potential for further development as an environmentally friendly food packaging material.展开更多
The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activate...The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.展开更多
Background: The full-thickness excision of malignant lower-eyelid tumors,particularly those with posterior lamellar involvement,presents a reconstructive challenge.Traditional grafts often have limitations,prompting i...Background: The full-thickness excision of malignant lower-eyelid tumors,particularly those with posterior lamellar involvement,presents a reconstructive challenge.Traditional grafts often have limitations,prompting interest in biocompatible alternatives,such as biodegradable diplene membranes.This study introduces a novel modification to the standard protocol: the use of diplene membranes enriched with Solcoseryl,a metabolically active agent that enhances angiogenesis,reduces inflammation,and accelerates epithelialization.Methods: Twenty-seven patients(mean age,68.96 ± 8.09 years) with histologically confirmed malignant lowereyelid tumors underwent reconstruction using diplene membranes combined with Solcoseryl.The outcomes were compared with those of a previously reported cohort treated with Diplene alone.The follow-up period ranged from 3 to 12 months.Results: All patients achieved successful restoration of eyelid support with high aesthetic satisfaction.The Solcoseryl group demonstrated significantly faster epithelialization(mean 9.8 ± 1.2 days),improved microcirculatory parameters,and no serious complications.Minor hematomas occurred in two cases(7.4%).Conclusion: The modified Diplene–Solcoseryl membrane enhanced wound healing and biocompatibility during lower-eyelid reconstruction by transforming the membrane into a bioactive scaffold.This innovation offers superior functional and aesthetic outcomes compared to standard diplene use and represents a significant advancement in oculoplastic and oncological reconstructive surgery.展开更多
Due to its excellent biocompatibility and biodegradability,Mg has received widespread attention in biomaterials as implants and even biobatteries.However,the poor corrosion resistance makes it difficult to meet the gr...Due to its excellent biocompatibility and biodegradability,Mg has received widespread attention in biomaterials as implants and even biobatteries.However,the poor corrosion resistance makes it difficult to meet the growing demand for implant materials.This study developed a biodegradable nano-heterogeneous Mg(48 wt%)-Zn(52 wt%)-based metal(NHMZ)comprising nanocrystalline matrix phase Mg_(51)Zn_(20) and nanoscale MgZn_(2) precipitates.The unique microstructure of NHMZ enhances its corrosion resistance.The spherical aberration-corrected transmission electron microscope(AC-TEM)and precession electron diffraction(PED)characterized the microstructures.The corrosion rate of NHMZ is about 0.21 mm y^(-1) after soaking for 4 weeks,approximately 58% of high pure Mg.In addition,the anode discharge of NHMZ is more stable than Mg,indicating it has great potential in biological batteries.This work hopes to broaden the development direction of biodegradable metallic materials and break through the performance limitation of current biodegradable Mg alloys.展开更多
[Objectives]This study was conducted to investigate the effects of lignin-based fully biodegradable plastic film on the growth and quality of lettuce under open-field cultivation conditions.[Methods]In this experiment...[Objectives]This study was conducted to investigate the effects of lignin-based fully biodegradable plastic film on the growth and quality of lettuce under open-field cultivation conditions.[Methods]In this experiment,compared with bare soil,a polyethylene plastic film(PE)treatment and two lignin-based fully biodegradable plastic film treatments(LBF-0.01 and LBF-0.008)with different thicknesses were set to study the effects on the growth and quality of lettuce.[Results]During autumn cultivation in Shanghai,the thermal insulation performance and yield-increasing effect of the two degradable plastic films were consistent with those of PE film,and effectively met lettuce growth requirements,but treatment LBF-0.01was better than treatment LBF-0.008.Moreover,lignin-based fully biodegradable plastic film could significantly increase the contents of Vc,soluble sugar and carotenoids in lettuce,and treatment LBF-0.008 showed the best effect.It could be seen that under the experimental conditions,the two kinds of lignin-based biodegradable plastic films with different thicknesses could be applied to the cultivation of lettuce in the open field in Shanghai in autumn,and LBF-0.01 had the best effect of increasing temperature and increasing yield,while LBF-0.008 had the best effect of improving quality.[Conclusions]This study provides theoretical basis and technical support for the further application of lignin-based fully biodegradable plastic film.展开更多
Polymeric materials,known for their lightweight and strength,are widely used today.However,their non-biodegradable nature poses significant environmental challenges.This research aimed to develop biodegradable films f...Polymeric materials,known for their lightweight and strength,are widely used today.However,their non-biodegradable nature poses significant environmental challenges.This research aimed to develop biodegradable films from fruits and vegetables,using alginate as a binding agent.Using a completely randomized design,seven experimental sets were prepared with carrots,Kimju guava,and Namwa banana peel fibers as the primary materials and alginate as the secondary material at three levels:1.2,1.8,and 2.4 by weight.The solution technique was employed to create the samples.Upon testing mechanical and physical properties,experimental set 3,consisting of 60%guava and 1.8%alginate,emerged as the optimal ratio.This combination exhibited favorable physical properties,including a thickness of 0.26±0.02 mm,meeting the standards for food packaging films.Additionally,the tensile strength was 0.50±0.01 N/m²,and the elongation at break was 55.60±0.44%.Regarding chemical properties,the moisture content of 5.64±0.03%fell within the acceptable range for dried food.Furthermore,a 30-day soil burial test revealed that the sample from experimental set 3 exhibited the highest degradation rate.In conclusion,these findings suggest that guava can be a promising raw material for producing biodegradable plastics suitable for packaging applications.展开更多
Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the e...Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the essential prerequisites for their successful clinical translation.Subsequently,a detailed review of magnesium-based materials is presented from five critical areas of alloying,fabrication techniques,purification,surface modification,and structural design,systematically addressing their progress in biodegradation rate retardation,mechanical reinforcement,and biocompatibility enhancement.Furthermore,recent breakthroughs in vivo animal experiments and clinical translation of magnesium alloys are summarized.Finally,this review concludes with a critical assessment of the achievements and challenges encountered in the clinical application of these materials,and proposes practical strategies to address current limitations and guide future research perspectives.展开更多
In response to the interest in degradable magnesium staples for oral and maxillofacial surgical procedures,high-performance Mg−3Zn−0.2Ca−2Ag alloy wires were reported.The impact of annealing temperature on the mechani...In response to the interest in degradable magnesium staples for oral and maxillofacial surgical procedures,high-performance Mg−3Zn−0.2Ca−2Ag alloy wires were reported.The impact of annealing temperature on the mechanical properties and corrosion behavior of the alloy wires was investigated.Results indicated that an increased annealing temperature led to grain growth,reduced the volume fraction of the second phase,and lowered dislocation density,causing decreased strength.The alloy annealed at 150℃exhibited the highest elongation(19.6%)due to uniform and fine grains,along with lower dislocation density.Microscopic observation,and electrochemical and immersion tests highlighted the significant influence of annealing temperature on corrosion rates.Alloy wires annealed at 150℃demonstrated superior corrosion resistance,which is attributed to small and uniform grains,low stress,and a well-distributed nano-second phase.Finally,the alloy wires annealed at 150℃exhibited enhanced comprehensive properties,making them good candidates for degradable staples.展开更多
In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhy...In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhydroxyalkanoate(PHA),on soil sulfamethoxazole(SMX)degradation and sul genes development were comparatively studied based on the type,dosage,and state.The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT>PHA and high dose>low dose.Meanwhile virgin PBAT significantly reduced soil pH.In general,the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes,with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes.The driving effects of BMPs on soil microbial diversity following the same order as that on DOC.Specific bacteria stimulated by BMPs,such as Arthrobacter and two genera affiliated with phylum TM7,accounted for the accelerated degradation of SMX.Intriguingly,UV-aging hindered the release of DOC from BMPs and the reduction in pH,mitigated the stimulation of microbial communities,and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation.Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.展开更多
The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.T...The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.This paper investigates the efects of pore structure and matrix composition on the corrosion behavior and mechanical properties of pure Zn.Porous Zn alloys with varying pore sizes were prepared via vacuum infltration casting.The results showed that addition of Mg elements and an increase in pore size were observed to enhance the strength and elastic modulus of the porous Zn alloy(41.34±0.113 MPa and 0.58±0.02 GPa of the C-Z3AM).However,corrosion tests indicated that specimens with smaller pores and the addition of Mg elements exhibited accelerated corrosion of porous Zn alloys in Hank’s solution.Electrochemical test results show the corrosion resistance rank in order of C-Z5A>C-Z3AM>N-Z5A>N-Z3AM.Additionally,the mechanical retention of porous Zn alloys in simulated body fuids was found to be signifcantly reduced by the incorporation of Mg elements and smaller pore sizes,the yield strength declines rates of C-Z5A,C-Z3AM and N-Z3AM after 30 days of immersion were 16.7%,63.7%and 78.2%,respectively.The objective is to establish the role of the material-structurecorrosion-mechanics relationship,which can provide a theoretical and experimental basis for the design and evaluation of Zn and its alloy implanted devices.展开更多
The management of agricultural wastes is essential for resource conservation and environmental sustainability.Due to escalating worries regarding plastic pollution and the surging expenses linked to petroleum-based pl...The management of agricultural wastes is essential for resource conservation and environmental sustainability.Due to escalating worries regarding plastic pollution and the surging expenses linked to petroleum-based plastics,there has been a notable transition towards the creation of biodegradable alternatives sourced from natural materials.Biofibres and bioplastics,especially those derived from agricultural waste,have garnered significant attention for their prospective uses in food packaging,biomedical sciences,and sustainable manufacturing.This study examines the viability of employing banana peel as a natural and environmentally sustainable raw material for the production of biodegradable bioplastic sheets.Due to its abundant polysaccharides and lignocellulosic fibers,banana peel presents advantageous structural and mechanical characteristics for bioplastic manufacturing.Experimental findings demonstrate that bioplastic derived from banana peels has enhanced biodegradability and environmental compatibility relative to traditional synthetic plastics,positioning it as a feasible alternative to mitigate the worldwide plastic waste epidemic.An optimal formulation was constructed using Design Expert software,comprising 55.38 g of banana peel,27.63 g of fish scales,and 20 g of chitosan powder.This formulation improves the film’s tensile strength,flexibility,and degradation rate,ensuring its efficacy in industrial applications including food packaging and molding.The study’s results highlight the promise of bioplastics made from banana peels as an economical and sustainable alternative,decreasing dependence on petroleum-based plastics and alleviating environmental pollution.展开更多
Photocatalysis holds great promise for the conversion of plastic waste into valuable chemicals.However,the conversion efficiency is constrained by the poor carriers’separation efficiency over the single component pho...Photocatalysis holds great promise for the conversion of plastic waste into valuable chemicals.However,the conversion efficiency is constrained by the poor carriers’separation efficiency over the single component photocatalyst.Herein,we synthesized a novel typeⅡNb_(2)O_(5)/GCN heterojunction to investigate its efficiency in the photocatalytic upcycling of polybutylene adipate/terephthalate(PBAT)microplastics(MPs)into acids and alcohols under visible light irradiation(100mW/cm^(2)).The findings indicate that the charge transfer within the typeⅡNb_(2)O_(5)/GCN occurs from the conduction band of GCN to the conduction band of Nb_(2)O_(5),thereby enhancing the separation efficiency of carriers Notably,the rates of ethanol and acetic acid generation from 1.5mg/mL PBAT MPs treated with the 60%Nb_(2)O_(5)/GCN photocatalyst were 21.8-fold and 1.8-fold higher,respectively,compared to those by Nb_(2)O_(5) alone.Density functional theory calculations demonstrate that the hydroxyl radicals(·OH)produced by the Nb_(2)O_(5)/GCN heterojunction cleaves the ester bond(O-C=O)of PBAT MP into the monomer.These monomers are subsequently converted into acids and alcohols through various reactions,including C-C bond cleavage,hydrodeoxygenation,and C-C bond coupling.This study highlights the effectiveness of heterojunction photocatalyst in converting PBAT MPs into valuable chemicals,thus significantly promoting advancements in bioplastics recycling.展开更多
Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristi...Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristics,interventional operation mode and postoperative management strategy.This article gives expert consensus on the selection of clinical indications and standardized operating procedures,so as to standardize the clinical application of biodegradable patent foramen ovale occluders.展开更多
Magnesium(Mg)alloys with biodegradability and excellent mechanical properties are in high demand for applications in guided bone regeneration(GBR).However,the clinical application of Mg alloys is hindered by infection...Magnesium(Mg)alloys with biodegradability and excellent mechanical properties are in high demand for applications in guided bone regeneration(GBR).However,the clinical application of Mg alloys is hindered by infection risks and limited osteogenesis.Herein,a structure-functional integrated Mg-Ca/Mg-Cu bilayer membrane was rolled at 150℃through various single-pass reductions by using online heating rolling.The Mg-Cu layer was specifically engineered to exhibit antibacterial properties tailored for gingival tissue,while the Mg-Ca layer was designed to support bone regeneration within the defect cavity.The bilayer membrane demonstrated a flexural yield strength of 421.0 MPa and a modulus of 58.6 GPa,indicating exceptional deformation resistance.Furthermore,it maintained notable structural stability by retaining 86.4%of its volume after 21 days in Hanks'solution.In vitro results revealed that the bilayer membrane exhibited favorable biocompatibility and promoted osteogenesis via the synergetic effect of released Mg^(2+)and Ca^(2+)ions.The rapid release of Cu^(2+)ions and the creation of an alkaline environment further improved antibacterial properties,potentially preventing postoperative infections.Additionally,in an in vivo rat calvarial defect model,the membrane demonstrated its capability to stimulate new bone formation.In summary,the Mg-Ca/Mg-Cu bilayer membrane exhibited outstanding mechanical stability,favorable corrosion rates,extraordinary osteogenic and antibacterial activity simultaneously.Consequently,it holds promise as a robust barrier membrane in GBR applications.展开更多
Biodegradable polylactic acid(PLA)melt-blown nonwovens are attractive candidates to replace nondegradable polypropylene melt-blown nonwovens.However,it is still an extremely challenging task to prepare PLA melt-blown ...Biodegradable polylactic acid(PLA)melt-blown nonwovens are attractive candidates to replace nondegradable polypropylene melt-blown nonwovens.However,it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application.Herein,we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)melt-blown nonwovens with high strength and excellent toughness.In this process,a small amount of PHBV is added to PLA to improve the latter’s crystallization rate and crystallinity.In addition,when the PHBV content increases from 0 to 7.5 wt%,the diameters of the PLA/PHBV melt-blown fibers decrease significantly(with the proportion of nanofibers increasing from 7.7%to 42.9%).The resultant PLA/PHBV(5 wt%PHBV)melt-blown nonwovens exhibit the highest mechanical properties.The tensile stress,elongation,and toughness of PLA/PHBV(5 wt%PHBV)melt-blown nonwovens reach 2.5 MPa,45%,and 1.0 MJm3,respectively.More importantly,PLA/PHBV melt-blown nonwovens can be completely degraded into carbon dioxide and water after four months in the soil,making them environmentally friendly.A general tensile-failure model of melt-blown nonwovens is proposed in this study,which may shed light on mechanical performance enhancement for nonwovens.展开更多
Biodegradable magnesium(Mg)alloys exhibit excellent biocompatibility,adequate mechanical properties,and osteogenic effect.They can contribute to complete recovery of damaged tissues without concerns about a second sur...Biodegradable magnesium(Mg)alloys exhibit excellent biocompatibility,adequate mechanical properties,and osteogenic effect.They can contribute to complete recovery of damaged tissues without concerns about a second surgery and have achieved clinical applications in orthopedic and cardiovascular fields.Porous scaffolds can provide functions such as bone integration and adjustable mechanical properties,thus widely used for bone repair.Additive manufacturing(AM)offers the advantages of design freedom and high precision,enabling the reliable production of porous scaffolds with customized structures.The combination of biodegradable Mg alloys,porous scaffolds,and AM processes has created tremendous opportunities for the precision treatment of bone defects.This article reviews the current development in the additive manufacturing process and design of Mg alloy biodegradable orthopedic implants,fo-cusing on chemical compositions,structural design,surface treatment,and their effects on mechanical properties,degradation behavior,and biocompatibility.Finally,the future perspective of porous Mg alloy biodegradable orthopedic implants is proposed.展开更多
基金supported by the National Key R&D Program of China(No.2022YFC3901800)the National Natural Science Foundation of China(No.22176041)Guangzhou Science and Technology Planning Project(No.2023A04J0918)。
文摘Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability properties.It is well known that PBAT suffers a series of natural weathering,mechanical wear,hydrolysis,photochemical transformation,and other abiotic degradation processes before being biodegraded.Therefore,it is particularly important to understand the role of abiotic degradation in the life cycle of PBAT.Since the abiotic degradation of PBAT has not been systematically summarized,this review aims to summarize the mechanisms and main factors of the three major abiotic degradation pathways(hydrolysis,photochemical transformation,and thermochemical degradation)of PBAT.It was found that all of them preferentially destroy the chemical bonds with higher energy(especially C-O and C=O)of PBAT,which eventually leads to the shortening of the polymer chain and then leads to reduction in molecular weight.The main factors affecting these abiotic degradations are closely related to the energy or PBAT structure.These findings provide important theoretical and practical guidance for identifying effective methods for PBAT waste management and proposing advanced schemes to regulate the degradation rate of PBAT.
文摘In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.
基金from"XingLiao Talent Program"of Liaoning Province(No.XLYC2203156)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(No.RC220397)are greatly acknowledged。
文摘Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification and good biocompatibility.However,as a result of the poor biodegradability of MsNs,their biomedical applications are limited.To break the bottleneck of limited biomedical applications of MSNs,more and more researchers tend to design biodegradable MSNs(b-MSNs)nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers.In this review,we focused on sum-marizing strategies to improve the degradability of MsNs and innovatively proposed a series of advan-tages of b-MsNs,including controlled cargo release behavior,multifunctional frameworks,nano-catalysis,bio-imaging capabilities and enhanced therapeutic effects.Based on these advantages,we have inno-vatively summarized the applications of b-MsNs for enhanced tumor theranostics,including enhanced chemotherapy,delivery of nanosensitizers,gas molecules and biomacromolecules,initiation of immune response,synergistic therapies and image-guided tumor diagnostics.Finally,the challenges and further clinical translation potential of nanosystems based on b-MsNs are fully discussed and prospected.We believe that such b-MsNs delivery carriers will provide a timely reference for further applications in tu-mor theranostics.
文摘Nowadays,the development of effective bioplastics aims to combine traditional plastics’functionality with environmentally friendly properties.The most effective and durable modern bioplastics are made from the edible part of crops.This forces bioplastics to competewith food production because the crops that produce bioplastics can also be used for human nutrition.That is why the article’s main focus is on creating bioplastics using renewable,non-food raw materials(cellulose,lignin,etc.).Eco-friendly composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)with reed and hemp waste as a filler.The physic-chemical features of the structure and surface,as well as the technological characteristics of reed and hemp waste as the organic fillers for renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid),were studied.Theeffect of the fractional composition analysis,morphology,and nature of reed and hempwaste on the quality of the design of eco-friendly biodegradable composites and their ability to disperse in the matrix of renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch and poly(lactic acid)was carried out.The influence of different content and morphology of reed and hemp waste on the composite characteristics was investigated.It is shown that the most optimal direction for obtaining strong eco-friendly biodegradable composites based on a renewable bioplastic blend of polybutylene adipate-co-terephthalate,corn starch,and poly(lactic acid)is associated with the use of waste reed stalks,with its optimal content at the level of 50 wt.%.
基金funded by a research grant from the Lembaga Pengelola Dana Pendidikan-Ministry of Finance Republic of Indonesia(https://risprolpdp.kemenkeu.go.id/)(accessed on 13 September 2024)awarded under the Riset dan Inovasi untuk Indonesia Maju program with grant number 82/II.7/HK/2022.
文摘This study aimed to develop and characterize biodegradable packaging film from blends of two natural polysaccharides,i.e.,agar and glucomannan.The glucomannan used was derived from the specific tuber plant Amorphophallus oncophyllus(locally known as“porang”),which grows abundantly in Indonesian forests and remains underutilized.Various ratios of agar and porang-glucomannan(PG)proportions were formulated to produce a food packaging film,which was subsequently tested for its mechanical,physical,chemical,and thermal properties.The results showed that the inclusion of PG to the film formulations notably enhanced the stretchability of agar films,achieving maximum a twofold increase,while concurrently reducing their water resistance such as increased water solubility and water swelling for up to 125%and 105%,respectively.The mechanical and thermal properties,as well as the water vapor permeability of the resulting film,were significantly affected by the polymer matrix structure formed by the varying proportions of the two biopolymers.The enhancement of these properties was associated with a more solid/compact film structure,as corroborated by cross-sectional images obtained through SEM analysis.The study’s findings suggest that utilizing agar and porang biomass has significant potential for further development as an environmentally friendly food packaging material.
基金supported by the Opening Project of National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,and the National Natural Science Foundation of China(No.52270017).
文摘The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.
文摘Background: The full-thickness excision of malignant lower-eyelid tumors,particularly those with posterior lamellar involvement,presents a reconstructive challenge.Traditional grafts often have limitations,prompting interest in biocompatible alternatives,such as biodegradable diplene membranes.This study introduces a novel modification to the standard protocol: the use of diplene membranes enriched with Solcoseryl,a metabolically active agent that enhances angiogenesis,reduces inflammation,and accelerates epithelialization.Methods: Twenty-seven patients(mean age,68.96 ± 8.09 years) with histologically confirmed malignant lowereyelid tumors underwent reconstruction using diplene membranes combined with Solcoseryl.The outcomes were compared with those of a previously reported cohort treated with Diplene alone.The follow-up period ranged from 3 to 12 months.Results: All patients achieved successful restoration of eyelid support with high aesthetic satisfaction.The Solcoseryl group demonstrated significantly faster epithelialization(mean 9.8 ± 1.2 days),improved microcirculatory parameters,and no serious complications.Minor hematomas occurred in two cases(7.4%).Conclusion: The modified Diplene–Solcoseryl membrane enhanced wound healing and biocompatibility during lower-eyelid reconstruction by transforming the membrane into a bioactive scaffold.This innovation offers superior functional and aesthetic outcomes compared to standard diplene use and represents a significant advancement in oculoplastic and oncological reconstructive surgery.
基金supported by grants from the National Natural Science Foundation of China(No.52201300)the National Key R&D Program of China(No.2023YFC2416800)+1 种基金China Postdoctoral Science Foundation(No.2021M702090)Changshu Science and Technology Program(Industrial)Project(No.CG202107).
文摘Due to its excellent biocompatibility and biodegradability,Mg has received widespread attention in biomaterials as implants and even biobatteries.However,the poor corrosion resistance makes it difficult to meet the growing demand for implant materials.This study developed a biodegradable nano-heterogeneous Mg(48 wt%)-Zn(52 wt%)-based metal(NHMZ)comprising nanocrystalline matrix phase Mg_(51)Zn_(20) and nanoscale MgZn_(2) precipitates.The unique microstructure of NHMZ enhances its corrosion resistance.The spherical aberration-corrected transmission electron microscope(AC-TEM)and precession electron diffraction(PED)characterized the microstructures.The corrosion rate of NHMZ is about 0.21 mm y^(-1) after soaking for 4 weeks,approximately 58% of high pure Mg.In addition,the anode discharge of NHMZ is more stable than Mg,indicating it has great potential in biological batteries.This work hopes to broaden the development direction of biodegradable metallic materials and break through the performance limitation of current biodegradable Mg alloys.
基金Supported by Shanghai Science and Technology Innovation Action Plan,China(22N51900900).
文摘[Objectives]This study was conducted to investigate the effects of lignin-based fully biodegradable plastic film on the growth and quality of lettuce under open-field cultivation conditions.[Methods]In this experiment,compared with bare soil,a polyethylene plastic film(PE)treatment and two lignin-based fully biodegradable plastic film treatments(LBF-0.01 and LBF-0.008)with different thicknesses were set to study the effects on the growth and quality of lettuce.[Results]During autumn cultivation in Shanghai,the thermal insulation performance and yield-increasing effect of the two degradable plastic films were consistent with those of PE film,and effectively met lettuce growth requirements,but treatment LBF-0.01was better than treatment LBF-0.008.Moreover,lignin-based fully biodegradable plastic film could significantly increase the contents of Vc,soluble sugar and carotenoids in lettuce,and treatment LBF-0.008 showed the best effect.It could be seen that under the experimental conditions,the two kinds of lignin-based biodegradable plastic films with different thicknesses could be applied to the cultivation of lettuce in the open field in Shanghai in autumn,and LBF-0.01 had the best effect of increasing temperature and increasing yield,while LBF-0.008 had the best effect of improving quality.[Conclusions]This study provides theoretical basis and technical support for the further application of lignin-based fully biodegradable plastic film.
基金funding from the Environmental Science Program for Academic Excellence and Community Research for Fiscal Year 2024,a financial resource of the Environmental Science and Technology Program,Faculty of Science,Buriram Rajabhat University.Additionally,Buriram Rajabhat University provided a publication budget.
文摘Polymeric materials,known for their lightweight and strength,are widely used today.However,their non-biodegradable nature poses significant environmental challenges.This research aimed to develop biodegradable films from fruits and vegetables,using alginate as a binding agent.Using a completely randomized design,seven experimental sets were prepared with carrots,Kimju guava,and Namwa banana peel fibers as the primary materials and alginate as the secondary material at three levels:1.2,1.8,and 2.4 by weight.The solution technique was employed to create the samples.Upon testing mechanical and physical properties,experimental set 3,consisting of 60%guava and 1.8%alginate,emerged as the optimal ratio.This combination exhibited favorable physical properties,including a thickness of 0.26±0.02 mm,meeting the standards for food packaging films.Additionally,the tensile strength was 0.50±0.01 N/m²,and the elongation at break was 55.60±0.44%.Regarding chemical properties,the moisture content of 5.64±0.03%fell within the acceptable range for dried food.Furthermore,a 30-day soil burial test revealed that the sample from experimental set 3 exhibited the highest degradation rate.In conclusion,these findings suggest that guava can be a promising raw material for producing biodegradable plastics suitable for packaging applications.
基金supported by the Science and Technology Planning Project of Guangdong Province(Nos.2024A0505040016 and 2023A0505050148)National Key Research and Development Project of China(2023YFB3809900/2023YFB3809902)Natural Science Foundation of Guangdong Province(No.2025A1515010026)。
文摘Biodegradable metals have garnered considerable interest owing to their capacity for self-degradation following the repair of damaged tissues.This review commences with their historical development and clarifies the essential prerequisites for their successful clinical translation.Subsequently,a detailed review of magnesium-based materials is presented from five critical areas of alloying,fabrication techniques,purification,surface modification,and structural design,systematically addressing their progress in biodegradation rate retardation,mechanical reinforcement,and biocompatibility enhancement.Furthermore,recent breakthroughs in vivo animal experiments and clinical translation of magnesium alloys are summarized.Finally,this review concludes with a critical assessment of the achievements and challenges encountered in the clinical application of these materials,and proposes practical strategies to address current limitations and guide future research perspectives.
基金The National Natural Science Foundation of China(Nos.51971020,52171097)the Major State Research and Development Program of China(No.2021YFB3701100)+1 种基金Key Scientific Research Project in Shanxi Province,China(No.202102050201003)the Opening Research Fund of State Key Laboratory for Advanced Metals and Materials,China(No.2023-Z03).
文摘In response to the interest in degradable magnesium staples for oral and maxillofacial surgical procedures,high-performance Mg−3Zn−0.2Ca−2Ag alloy wires were reported.The impact of annealing temperature on the mechanical properties and corrosion behavior of the alloy wires was investigated.Results indicated that an increased annealing temperature led to grain growth,reduced the volume fraction of the second phase,and lowered dislocation density,causing decreased strength.The alloy annealed at 150℃exhibited the highest elongation(19.6%)due to uniform and fine grains,along with lower dislocation density.Microscopic observation,and electrochemical and immersion tests highlighted the significant influence of annealing temperature on corrosion rates.Alloy wires annealed at 150℃demonstrated superior corrosion resistance,which is attributed to small and uniform grains,low stress,and a well-distributed nano-second phase.Finally,the alloy wires annealed at 150℃exhibited enhanced comprehensive properties,making them good candidates for degradable staples.
基金supported by the National Key Plan for Research and Development of China(Nos.2022YFE0120300 and 2020YFC1806902)the National Natural Science Foundation of China(Nos.42161134002,81991535,and 41877058)the Natural Science Foundation of Fujian Province,China(No.2022J01509).
文摘In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhydroxyalkanoate(PHA),on soil sulfamethoxazole(SMX)degradation and sul genes development were comparatively studied based on the type,dosage,and state.The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT>PHA and high dose>low dose.Meanwhile virgin PBAT significantly reduced soil pH.In general,the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes,with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes.The driving effects of BMPs on soil microbial diversity following the same order as that on DOC.Specific bacteria stimulated by BMPs,such as Arthrobacter and two genera affiliated with phylum TM7,accounted for the accelerated degradation of SMX.Intriguingly,UV-aging hindered the release of DOC from BMPs and the reduction in pH,mitigated the stimulation of microbial communities,and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation.Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.
基金supported by the Shaanxi Qinchuangyuan Cited High-level Innovation and Entrepreneurial Talents Project(Nos.QCYRCXM-2022-156,QCYRCXM-2022-52,QCYRCXM-2023-181)the Fundamental Research Funds for the Central Universities(N2225010)+2 种基金the Yingkou Enterprise Doctoral Innovation and Entrepreneurship Plan(YKSCJH2023-007)the Natural Science Basic Research Program of Shaanxi Province(2023-JC-QN-0378,2023-YBSF-561)the Shaanxi Provincial Key R&D Program(2024SF-YBXM-442).
文摘The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.This paper investigates the efects of pore structure and matrix composition on the corrosion behavior and mechanical properties of pure Zn.Porous Zn alloys with varying pore sizes were prepared via vacuum infltration casting.The results showed that addition of Mg elements and an increase in pore size were observed to enhance the strength and elastic modulus of the porous Zn alloy(41.34±0.113 MPa and 0.58±0.02 GPa of the C-Z3AM).However,corrosion tests indicated that specimens with smaller pores and the addition of Mg elements exhibited accelerated corrosion of porous Zn alloys in Hank’s solution.Electrochemical test results show the corrosion resistance rank in order of C-Z5A>C-Z3AM>N-Z5A>N-Z3AM.Additionally,the mechanical retention of porous Zn alloys in simulated body fuids was found to be signifcantly reduced by the incorporation of Mg elements and smaller pore sizes,the yield strength declines rates of C-Z5A,C-Z3AM and N-Z3AM after 30 days of immersion were 16.7%,63.7%and 78.2%,respectively.The objective is to establish the role of the material-structurecorrosion-mechanics relationship,which can provide a theoretical and experimental basis for the design and evaluation of Zn and its alloy implanted devices.
文摘The management of agricultural wastes is essential for resource conservation and environmental sustainability.Due to escalating worries regarding plastic pollution and the surging expenses linked to petroleum-based plastics,there has been a notable transition towards the creation of biodegradable alternatives sourced from natural materials.Biofibres and bioplastics,especially those derived from agricultural waste,have garnered significant attention for their prospective uses in food packaging,biomedical sciences,and sustainable manufacturing.This study examines the viability of employing banana peel as a natural and environmentally sustainable raw material for the production of biodegradable bioplastic sheets.Due to its abundant polysaccharides and lignocellulosic fibers,banana peel presents advantageous structural and mechanical characteristics for bioplastic manufacturing.Experimental findings demonstrate that bioplastic derived from banana peels has enhanced biodegradability and environmental compatibility relative to traditional synthetic plastics,positioning it as a feasible alternative to mitigate the worldwide plastic waste epidemic.An optimal formulation was constructed using Design Expert software,comprising 55.38 g of banana peel,27.63 g of fish scales,and 20 g of chitosan powder.This formulation improves the film’s tensile strength,flexibility,and degradation rate,ensuring its efficacy in industrial applications including food packaging and molding.The study’s results highlight the promise of bioplastics made from banana peels as an economical and sustainable alternative,decreasing dependence on petroleum-based plastics and alleviating environmental pollution.
基金financially supported by the National Natural Science Foundation of China(Nos.52170024,T2421005,and 22006031).
文摘Photocatalysis holds great promise for the conversion of plastic waste into valuable chemicals.However,the conversion efficiency is constrained by the poor carriers’separation efficiency over the single component photocatalyst.Herein,we synthesized a novel typeⅡNb_(2)O_(5)/GCN heterojunction to investigate its efficiency in the photocatalytic upcycling of polybutylene adipate/terephthalate(PBAT)microplastics(MPs)into acids and alcohols under visible light irradiation(100mW/cm^(2)).The findings indicate that the charge transfer within the typeⅡNb_(2)O_(5)/GCN occurs from the conduction band of GCN to the conduction band of Nb_(2)O_(5),thereby enhancing the separation efficiency of carriers Notably,the rates of ethanol and acetic acid generation from 1.5mg/mL PBAT MPs treated with the 60%Nb_(2)O_(5)/GCN photocatalyst were 21.8-fold and 1.8-fold higher,respectively,compared to those by Nb_(2)O_(5) alone.Density functional theory calculations demonstrate that the hydroxyl radicals(·OH)produced by the Nb_(2)O_(5)/GCN heterojunction cleaves the ester bond(O-C=O)of PBAT MP into the monomer.These monomers are subsequently converted into acids and alcohols through various reactions,including C-C bond cleavage,hydrodeoxygenation,and C-C bond coupling.This study highlights the effectiveness of heterojunction photocatalyst in converting PBAT MPs into valuable chemicals,thus significantly promoting advancements in bioplastics recycling.
基金Chinese Academy of Medical Sciences Fuwai Hospital High Level Hospital clinical research fund(2022-GSPGG-18).
文摘Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristics,interventional operation mode and postoperative management strategy.This article gives expert consensus on the selection of clinical indications and standardized operating procedures,so as to standardize the clinical application of biodegradable patent foramen ovale occluders.
基金supported by the National Natural Science Foundation of China(51972339,52072023,and 51802350)the National Natural Science Found for Distinguished Young Scholars(52225101)+3 种基金the China Postdoctoral Science Foundation(2022M720551)the Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0527,cstc2021jcyj-msxmX0993)the Chongqing Academician Special Fund(2022YSZX-JCX0014CSTB)the Chongqing Science and Technology Commission(CSTB2022NSCQ-MSX0416).
文摘Magnesium(Mg)alloys with biodegradability and excellent mechanical properties are in high demand for applications in guided bone regeneration(GBR).However,the clinical application of Mg alloys is hindered by infection risks and limited osteogenesis.Herein,a structure-functional integrated Mg-Ca/Mg-Cu bilayer membrane was rolled at 150℃through various single-pass reductions by using online heating rolling.The Mg-Cu layer was specifically engineered to exhibit antibacterial properties tailored for gingival tissue,while the Mg-Ca layer was designed to support bone regeneration within the defect cavity.The bilayer membrane demonstrated a flexural yield strength of 421.0 MPa and a modulus of 58.6 GPa,indicating exceptional deformation resistance.Furthermore,it maintained notable structural stability by retaining 86.4%of its volume after 21 days in Hanks'solution.In vitro results revealed that the bilayer membrane exhibited favorable biocompatibility and promoted osteogenesis via the synergetic effect of released Mg^(2+)and Ca^(2+)ions.The rapid release of Cu^(2+)ions and the creation of an alkaline environment further improved antibacterial properties,potentially preventing postoperative infections.Additionally,in an in vivo rat calvarial defect model,the membrane demonstrated its capability to stimulate new bone formation.In summary,the Mg-Ca/Mg-Cu bilayer membrane exhibited outstanding mechanical stability,favorable corrosion rates,extraordinary osteogenic and antibacterial activity simultaneously.Consequently,it holds promise as a robust barrier membrane in GBR applications.
基金supported by the National Key Research and Development Program of China(2022YFB3804903 and 2022YFB3804900)the National Natural Science Foundation of China(52273052)+1 种基金the Program of Shanghai Academic/Technology Research Leader(21XD1420100)the International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(21130750100).
文摘Biodegradable polylactic acid(PLA)melt-blown nonwovens are attractive candidates to replace nondegradable polypropylene melt-blown nonwovens.However,it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application.Herein,we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)melt-blown nonwovens with high strength and excellent toughness.In this process,a small amount of PHBV is added to PLA to improve the latter’s crystallization rate and crystallinity.In addition,when the PHBV content increases from 0 to 7.5 wt%,the diameters of the PLA/PHBV melt-blown fibers decrease significantly(with the proportion of nanofibers increasing from 7.7%to 42.9%).The resultant PLA/PHBV(5 wt%PHBV)melt-blown nonwovens exhibit the highest mechanical properties.The tensile stress,elongation,and toughness of PLA/PHBV(5 wt%PHBV)melt-blown nonwovens reach 2.5 MPa,45%,and 1.0 MJm3,respectively.More importantly,PLA/PHBV melt-blown nonwovens can be completely degraded into carbon dioxide and water after four months in the soil,making them environmentally friendly.A general tensile-failure model of melt-blown nonwovens is proposed in this study,which may shed light on mechanical performance enhancement for nonwovens.
基金funded by the National Key Research and Devel-opment Program of China(2018YFE0104200)the National Natural Science Foundation of China(52175274,82172065,and 51875310)+1 种基金the Tsinghua-Toyota Joint Research Fund,the Tsinghua Precision Medicine Foundationthe Cross-Strait Tsinghua Research Insti-tute Fund.
文摘Biodegradable magnesium(Mg)alloys exhibit excellent biocompatibility,adequate mechanical properties,and osteogenic effect.They can contribute to complete recovery of damaged tissues without concerns about a second surgery and have achieved clinical applications in orthopedic and cardiovascular fields.Porous scaffolds can provide functions such as bone integration and adjustable mechanical properties,thus widely used for bone repair.Additive manufacturing(AM)offers the advantages of design freedom and high precision,enabling the reliable production of porous scaffolds with customized structures.The combination of biodegradable Mg alloys,porous scaffolds,and AM processes has created tremendous opportunities for the precision treatment of bone defects.This article reviews the current development in the additive manufacturing process and design of Mg alloy biodegradable orthopedic implants,fo-cusing on chemical compositions,structural design,surface treatment,and their effects on mechanical properties,degradation behavior,and biocompatibility.Finally,the future perspective of porous Mg alloy biodegradable orthopedic implants is proposed.
