Biomass‐Derived Multilayer‐Structured Microparticles for Accelerated Hemostasis and Bone Repair

It is very desirable to develop advanced sustainable biomedical materials with superior biosafety and bioactivity for clinical applications. Herein, biomass‐derived multilayer‐structured absorbable microparticles (MQ(x)T(y)) composed of starches and plant polyphenols are readily constructed for the safe and effective treatment of bone defects with intractable bleeding by coating multiple layers of quaternized starch (Q(+)) and tannic acid onto microporous starch microparticles via facile layer‐by‐layer assembly. MQ(x)T(y) microparticles exhibit efficient degradability, low cytotoxicity, and good blood compatibility. Among various MQ(x)T(y) microparticles with distinct Q(+)/T(−) double layers, MQ(2)T(2) with outmost polyphenol layer possess the unique properties of platelet adhesion/activation and red blood cell aggregation, resulting in the best hemostatic performance. In a mouse cancellous‐bone‐defect model, MQ(2)T(2) exhibits the favorable hemostatic effect, low inflammation/immune responses, high biodegradability, and promoted bone repair. A proof‐of‐concept study of beagles further confirms the good performance of MQ(2)T(2) in controlling intractable bleeding of bone defects. The present work demonstrates that such biomass‐based multilayer‐structured microparticles are very promising biomedical materials for clinical use.