Kneadable dough-type hydrogel transforming from dynamic to rigid network to repair irregular bone defects

Irregular bone defects,characterized by unpredictable size,shape,and depth,pose a major challenge to clinical treatment.Although various bone grafts are available,none can fully meet the repair needs of the defective area.Here,this study fabricates a dough-type hydrogel(DR-Net),in which the first dynamic network is generated by coordination between thiol groups and silver ions,thereby possessing kneadability to adapt to various irregular bone defects.The second rigid covalent network is formed through photocrosslinking,maintaining the osteogenic space under external forces and achieving a better match with the bone regeneration process.In vitro,an irregular alveolar bone defect is established in the fresh porcine mandible,and the dough-type hydrogel exhibits outstanding shape adaptability,perfectly matching the morphology of the bone defect.After photocuring,the storage modulus of the hydrogel increases 8.6 times,from 3.7 kPa(before irradiation)to 32 kPa(after irradiation).Furthermore,this hydrogel enables effective loading of P24 peptide,which potently accelerates bone repair in Sprague–Dawley(SD)rats with critical calvarial defects.Overall,the dough-type hydrogel with kneadability,space-maintaining capability,and osteogenic activity exhibits exceptional potential for clinical translation in treating irregular bone defects.

不同生态环境下对新疆冬小麦品种面团流变学特性的影响

【目的】了解生态环境对新疆冬小麦品种面团流变学特性的影响。【方法】选择用新疆7个冬小麦品种于2009、2010年在6个海拔区(473～1 422 m)种植,探讨生态环境对冬小麦品种面团流变学特性的影响。【结果】面团流变学特性指标在基因型、环境(除形成时间外)间呈显著或极显著差异。不同品质类型品种间、不同地点间冬小麦面团流变学特性变化不同。三种筋型冬麦品种在稳定时间、评价值、最大拉伸阻力间的差异均显著;中强筋类和中弱筋类的形成时间、延伸性差异不显著,与强筋类差异显著;强筋类和中强筋类的吸水率、弱化度差异不显著,与弱筋类差异显著。随着海拔递增,三种筋型小麦弱化度升高,最大拉伸阻力、拉伸面积则降低。强筋类面团流变学特性主要指标在乌鲁木齐点表现最好,于田点最差。生态因子与面团流变学特性的分析表明,海拔高度与吸水率、弱化度呈极显著正相关,与延伸性、最大拉伸阻力、拉伸面积呈极显著负相关。平均温度与吸水率、形成时间、评价值呈显著或极显著负相关;与延伸性、拉伸面积、最大拉伸阻力呈显著或极显著正相关。光照对吸水率、形成时间呈显著正效应,与弱化度、最大拉伸阻力、拉伸面积呈显著或极显著负效应。而降水量与面团流变学特性的相关性均不显著。【结论】强筋类品种在新疆北部地区的表现好于南部地区;而中强筋和中弱筋类在上述区域均适宜种植。

淀粉种类对重组粉面团的流变学特性的影响

选取7种不同淀粉与谷朊粉重组,对重组粉面团的流变学特性和微观结构进行研究,探讨淀粉种类是否是影响重组粉面团性质的主要原因。研究表明:淀粉类型能明显影响重组粉面团的流变学特性和微观结构。各重组面团的动态频率扫描的恒定应变值为0. 05%,弹性、黏性模量和角频率的关系与Power-law方程的拟合度良好。各淀粉重组面团的弹性:大米最大,依次为红薯、土豆、豌豆、小麦、玉米和青稞淀粉重组面团。黏性与弹性的趋势类似,前3位依次是红薯、土豆和大米,其余顺序不变。流动性强弱的顺序为:青稞、土豆>红薯、豌豆、小麦>玉米>大米淀粉重组面团。各面团的蠕变-恢复试验中,青稞的形变最大,土豆、小麦、玉米、红薯和豌豆面团次之,大米淀粉重组面团的形变最小。面团内淀粉结合的紧密程度:小麦、青稞>玉米、红薯>豌豆、土豆和大米淀粉重组面团。