Hydrophilic degraded gelatin was modified with hydrophobic poly(ε-caprolactone) (PCL) via a chemical grafting route.Firstly,PCL with one hydroxyl end group was prepared by the ring-opening polymerization of εcaprola...Hydrophilic degraded gelatin was modified with hydrophobic poly(ε-caprolactone) (PCL) via a chemical grafting route.Firstly,PCL with one hydroxyl end group was prepared by the ring-opening polymerization of εcaprolactone (ε-CL) with tin (Ⅱ) 2-ethylhexanoate as catalyst and n-butyl alcohol as initiator.Secondly,the PCL reacted with isophorone diisocyanate (IPDI) to prepare PCL with isocyanate functional group (PCL-NCO).Hydroxylamine was used to degrade gelatin by the cleavage between asparagine and glycine residues of gelatin.PCL-NCO reacted with the hydroxyl/amino groups of degraded gelatin in a homogeneous system and yielded the PCL modified gelatin copolymers.The gelatin grafted PCL copolymers were measured by means of XRD,FTIR,DSC and 1 H NMR.The results confirmed the conjugation of PCL onto gelatin chains.The PCL modified gelatin can be used as biomaterials owing to their biocompatibility and biodegradation.展开更多
A series of novel copolymers were successfully synthesized by ring-opening polymerization(ROP) of 3(S)-methyl-morpholine-2,5-dione(MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one(MBC) using stannous octoate as ...A series of novel copolymers were successfully synthesized by ring-opening polymerization(ROP) of 3(S)-methyl-morpholine-2,5-dione(MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one(MBC) using stannous octoate as catalyst.The copolymers were characterized by means of 1 H-NMR and FT-IR spectroscopy.Gel permeation chromatography(GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed.The results of differential scanning calorimetry(DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers.The copolymers of MMD and MBC are amorphous copolymers,as indicated by DSC results,while the homopolymer of MMD is semicrystalline.展开更多
Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects.Poly(α-amino acid)-b-poly(tetrahydrofuran)-b-poly(α-amino acid)(PAA-PTHF...Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects.Poly(α-amino acid)-b-poly(tetrahydrofuran)-b-poly(α-amino acid)(PAA-PTHF-PAA)is one of the copolymers.In this contribution,di-hydroxyl-ended HO-PTHF-OH is transferred into di-oxyamino-ended H2NO-PTHF-ONH2 quantitatively,which is used as a macroinitiator to polymerize sarcosine N-thiocarboxyanhydride(Sar-NTA)and N-phenyoxycarbonyl N-ε-carbobenzyloxy-D-lysine(ZDL-NPC).Well-defined triblock PAA-NHO-PTHF-ONH-PAA is produced with high molecular weight(up to 25.3 kg/mol)and narrow dispersity.The amphiphilic PSar-NHO-PTHF-ONH-PSar(STS)self-assembles into micelles with uniform diameters of 30—40 nm according to DLS.Owing to oxygen amide groups inside the backbone of these copolymers,the polyether-poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.展开更多
Antimicrobial peptides(AMPs)have been considered as an alternative to small molecule antibiotics since they are difficult to develop antimicrobial resistance.Hyperbranched polylysine(HPL),an AMP mimics,has gained atte...Antimicrobial peptides(AMPs)have been considered as an alternative to small molecule antibiotics since they are difficult to develop antimicrobial resistance.Hyperbranched polylysine(HPL),an AMP mimics,has gained attention due to its broad-spectrum antibacterial activities,but it also suffers from high toxicity.Here we report a facile strategy to engineer the toxicity of HPL by copolymerizing lysine(K)with a hydrophobic amino acid,e.g.,alanine(A),tryptophan(W)or phenylalanine(F),to afford hyperbranched random copolymers.These copolymers have comparable antibacterial activities to HPL while their cytotoxicities and in vivo toxicities are lowered when the type and content of hydrophobic amino acid and the size of copolymers are optimized.The G.mellonella infection model demonstrates that the copolymers are effective against the S.aureus infection in vivo.The copolymers kill the bacteria through the disruption of cell membranes and the bacteria do not develop resistance to the copolymers.展开更多
通过原位聚合法制备新型生物活性羟基磷灰石/二元氨基酸共聚物(BHA/PAA)复合材料。采用1 H核磁共振(1 H NMR)、红外光谱(IR)、X-ray衍射光谱(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)和差示扫描量热分析(DSC)对其组成结构、热性能、...通过原位聚合法制备新型生物活性羟基磷灰石/二元氨基酸共聚物(BHA/PAA)复合材料。采用1 H核磁共振(1 H NMR)、红外光谱(IR)、X-ray衍射光谱(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)和差示扫描量热分析(DSC)对其组成结构、热性能、力学性能和体外降解性能进行研究。结果表明:BHA颗粒均匀分散在PAA基质中,形成的复合材料具有良好的均一性;复合材料的无机相和有机相之间存在着一定的化学键相互作用;由于BHA的引入,复合材料的结晶速率加快,整体结晶度下降;复合材料具有良好的力学性能,其抗压强度随着BHA含量的增加而明显提高,抗弯强度略有减小,当BHA含量为30%(质量分数)时,复合材料的抗压强度和抗弯强度分别为141.02MPa和86.32MPa,力学性能与人体皮质骨相匹配;体外降解实验结果表明,随着BHA含量的增加,材料的降解速率加快,且在降解过程中保持良好的力学性能稳定性,在骨修复方面具有潜在的应用。展开更多
基金Supported by International Cooperation from Ministry of Science and Technology of China(No.2008DFA51170)
文摘Hydrophilic degraded gelatin was modified with hydrophobic poly(ε-caprolactone) (PCL) via a chemical grafting route.Firstly,PCL with one hydroxyl end group was prepared by the ring-opening polymerization of εcaprolactone (ε-CL) with tin (Ⅱ) 2-ethylhexanoate as catalyst and n-butyl alcohol as initiator.Secondly,the PCL reacted with isophorone diisocyanate (IPDI) to prepare PCL with isocyanate functional group (PCL-NCO).Hydroxylamine was used to degrade gelatin by the cleavage between asparagine and glycine residues of gelatin.PCL-NCO reacted with the hydroxyl/amino groups of degraded gelatin in a homogeneous system and yielded the PCL modified gelatin copolymers.The gelatin grafted PCL copolymers were measured by means of XRD,FTIR,DSC and 1 H NMR.The results confirmed the conjugation of PCL onto gelatin chains.The PCL modified gelatin can be used as biomaterials owing to their biocompatibility and biodegradation.
基金Supported by Chinese Program for New Century Excellent Talents in University "NCET",Ministry of Education of P.R. China(No.2008DFA51170)
文摘A series of novel copolymers were successfully synthesized by ring-opening polymerization(ROP) of 3(S)-methyl-morpholine-2,5-dione(MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one(MBC) using stannous octoate as catalyst.The copolymers were characterized by means of 1 H-NMR and FT-IR spectroscopy.Gel permeation chromatography(GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed.The results of differential scanning calorimetry(DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers.The copolymers of MMD and MBC are amorphous copolymers,as indicated by DSC results,while the homopolymer of MMD is semicrystalline.
基金supported by the Joint Foundation of Shaanxi Province Natural Science Basic Research Program and Shaanxi Coal Chemical Group Cov Ltd.(No.2019JLM-46)the National Natural Science Foundation of China(No.21674091).
文摘Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects.Poly(α-amino acid)-b-poly(tetrahydrofuran)-b-poly(α-amino acid)(PAA-PTHF-PAA)is one of the copolymers.In this contribution,di-hydroxyl-ended HO-PTHF-OH is transferred into di-oxyamino-ended H2NO-PTHF-ONH2 quantitatively,which is used as a macroinitiator to polymerize sarcosine N-thiocarboxyanhydride(Sar-NTA)and N-phenyoxycarbonyl N-ε-carbobenzyloxy-D-lysine(ZDL-NPC).Well-defined triblock PAA-NHO-PTHF-ONH-PAA is produced with high molecular weight(up to 25.3 kg/mol)and narrow dispersity.The amphiphilic PSar-NHO-PTHF-ONH-PSar(STS)self-assembles into micelles with uniform diameters of 30—40 nm according to DLS.Owing to oxygen amide groups inside the backbone of these copolymers,the polyether-poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.
基金financially supported by the National Natural Science Foundation of China(No.51973212)Department of Science and Technology of Jilin Province(Nos.20210203119SF and 20210203173SF)。
文摘Antimicrobial peptides(AMPs)have been considered as an alternative to small molecule antibiotics since they are difficult to develop antimicrobial resistance.Hyperbranched polylysine(HPL),an AMP mimics,has gained attention due to its broad-spectrum antibacterial activities,but it also suffers from high toxicity.Here we report a facile strategy to engineer the toxicity of HPL by copolymerizing lysine(K)with a hydrophobic amino acid,e.g.,alanine(A),tryptophan(W)or phenylalanine(F),to afford hyperbranched random copolymers.These copolymers have comparable antibacterial activities to HPL while their cytotoxicities and in vivo toxicities are lowered when the type and content of hydrophobic amino acid and the size of copolymers are optimized.The G.mellonella infection model demonstrates that the copolymers are effective against the S.aureus infection in vivo.The copolymers kill the bacteria through the disruption of cell membranes and the bacteria do not develop resistance to the copolymers.
文摘通过原位聚合法制备新型生物活性羟基磷灰石/二元氨基酸共聚物(BHA/PAA)复合材料。采用1 H核磁共振(1 H NMR)、红外光谱(IR)、X-ray衍射光谱(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)和差示扫描量热分析(DSC)对其组成结构、热性能、力学性能和体外降解性能进行研究。结果表明:BHA颗粒均匀分散在PAA基质中,形成的复合材料具有良好的均一性;复合材料的无机相和有机相之间存在着一定的化学键相互作用;由于BHA的引入,复合材料的结晶速率加快,整体结晶度下降;复合材料具有良好的力学性能,其抗压强度随着BHA含量的增加而明显提高,抗弯强度略有减小,当BHA含量为30%(质量分数)时,复合材料的抗压强度和抗弯强度分别为141.02MPa和86.32MPa,力学性能与人体皮质骨相匹配;体外降解实验结果表明,随着BHA含量的增加,材料的降解速率加快,且在降解过程中保持良好的力学性能稳定性,在骨修复方面具有潜在的应用。
