骨软骨组织具有独特生物力学特性,通过机械生物学策略可显著促进骨软骨再生。组织工程是一种极具临床应用潜力的方案,但目前缺乏自适应于修复中动态力学微环境变化的支架。基于此,本团队设计了酶响应动态聚氨基酸水凝胶以提供时空生物...骨软骨组织具有独特生物力学特性,通过机械生物学策略可显著促进骨软骨再生。组织工程是一种极具临床应用潜力的方案,但目前缺乏自适应于修复中动态力学微环境变化的支架。基于此,本团队设计了酶响应动态聚氨基酸水凝胶以提供时空生物力学动态的机械线索给干细胞,诱导其在不同阶段、不同层有不同增殖、分化行为。本文通过双交联网络结构设计提供动态力学线索。基于测定骨软骨微环境中碱性磷酸酶(ALP)活性梯度,在光交联第一网络基础上,ALP响应化学交联网络作为第二网络,在时间尺度上,满足在初期细胞增殖需求,较低硬度利于细胞增殖,在后期细胞分化阶段,软骨层能保持较低硬度促成软骨,而在软骨下骨层能动态增强力学性能成硬凝胶来调控成骨分化,形成空间尺度上自生梯度支架可精准高效促进骨软骨全层修复。酶响应聚氨基酸水凝胶在ALP作用下,储能模量随着酶催化时间的增加而增加(3 k Pa增至10 k Pa),这主要由于去磷酸化后生物正交化学交联度增加,第二交联网络形成,力学性能增加。在植入于兔膝关节骨软骨缺损部位8周,相比较于空白组和光交联单网络水凝胶组相比,酶响应双网络水凝胶组实现了全层高效再生修复,验证了动态自适应的力学梯度支架更有利于骨软骨全层再生。展开更多
Novel physically cross-linked hydrogels, composed of PVA and hydroxy-terminated polyamidoamine(PAMAM) dendrimer G6-OH, were prepared by cyclic freezing/thawing treatment of aqueous solutions containing PVA and G6-OH. ...Novel physically cross-linked hydrogels, composed of PVA and hydroxy-terminated polyamidoamine(PAMAM) dendrimer G6-OH, were prepared by cyclic freezing/thawing treatment of aqueous solutions containing PVA and G6-OH. FTIR analysis indicates that PAMAM dendrimer G6-OH was successfully introduced into PVA hydrogels. Higher contents of G6-OH in PVA/G6-OH hydrogels resulted in higher swelling ratios, and faster reswelling rates. With the increase of freezing/thawing cyclic times, the swelling ratios and reswelling rates of PVA/G6-OH hydrogels decreased, which is similar to that of physically cross-linked PVA hydrogel.展开更多
In this paper, the polypseudorotaxanes were synthesized from α-cyclodextrins(α-CDs) threaded onto PCL-PEG-PCL macromers terminated with acrylate groups. Then, supramolecular-structured hydrogels were prepared from t...In this paper, the polypseudorotaxanes were synthesized from α-cyclodextrins(α-CDs) threaded onto PCL-PEG-PCL macromers terminated with acrylate groups. Then, supramolecular-structured hydrogels were prepared from the polyseudorotaxanes in a mixed solvent of H 2O and DMSO via in-situ polymerization photoinitiated under UV. The structure and properties of the supramolecular-structured hydrogels were characterized by FTIR, TGA and WAXD. The results showed that α-CDs were threaded and immobilized on the network of the hydrogel by rapid photopolymerization, and the feed ratio of α-CDs affected the structure of hydrogels, water absorption, the distribution and states of water, etc..展开更多
文摘骨软骨组织具有独特生物力学特性,通过机械生物学策略可显著促进骨软骨再生。组织工程是一种极具临床应用潜力的方案,但目前缺乏自适应于修复中动态力学微环境变化的支架。基于此,本团队设计了酶响应动态聚氨基酸水凝胶以提供时空生物力学动态的机械线索给干细胞,诱导其在不同阶段、不同层有不同增殖、分化行为。本文通过双交联网络结构设计提供动态力学线索。基于测定骨软骨微环境中碱性磷酸酶(ALP)活性梯度,在光交联第一网络基础上,ALP响应化学交联网络作为第二网络,在时间尺度上,满足在初期细胞增殖需求,较低硬度利于细胞增殖,在后期细胞分化阶段,软骨层能保持较低硬度促成软骨,而在软骨下骨层能动态增强力学性能成硬凝胶来调控成骨分化,形成空间尺度上自生梯度支架可精准高效促进骨软骨全层修复。酶响应聚氨基酸水凝胶在ALP作用下,储能模量随着酶催化时间的增加而增加(3 k Pa增至10 k Pa),这主要由于去磷酸化后生物正交化学交联度增加,第二交联网络形成,力学性能增加。在植入于兔膝关节骨软骨缺损部位8周,相比较于空白组和光交联单网络水凝胶组相比,酶响应双网络水凝胶组实现了全层高效再生修复,验证了动态自适应的力学梯度支架更有利于骨软骨全层再生。
文摘Novel physically cross-linked hydrogels, composed of PVA and hydroxy-terminated polyamidoamine(PAMAM) dendrimer G6-OH, were prepared by cyclic freezing/thawing treatment of aqueous solutions containing PVA and G6-OH. FTIR analysis indicates that PAMAM dendrimer G6-OH was successfully introduced into PVA hydrogels. Higher contents of G6-OH in PVA/G6-OH hydrogels resulted in higher swelling ratios, and faster reswelling rates. With the increase of freezing/thawing cyclic times, the swelling ratios and reswelling rates of PVA/G6-OH hydrogels decreased, which is similar to that of physically cross-linked PVA hydrogel.
文摘In this paper, the polypseudorotaxanes were synthesized from α-cyclodextrins(α-CDs) threaded onto PCL-PEG-PCL macromers terminated with acrylate groups. Then, supramolecular-structured hydrogels were prepared from the polyseudorotaxanes in a mixed solvent of H 2O and DMSO via in-situ polymerization photoinitiated under UV. The structure and properties of the supramolecular-structured hydrogels were characterized by FTIR, TGA and WAXD. The results showed that α-CDs were threaded and immobilized on the network of the hydrogel by rapid photopolymerization, and the feed ratio of α-CDs affected the structure of hydrogels, water absorption, the distribution and states of water, etc..
