Bioinspired Alginate/α‐TCP Organic–Inorganic Interpenetrating Network Microspheres for Bone Repair

Abstract Minimally invasive regenerative therapies based on bone cement hold significant application value in the field of bone defect repair. However, existing materials such as calcium phosphate cement (CPC) suffer from limitations including insufficient mechanical strength, susceptibility to disintegration, and lack of porous structure. In this study, a dual‐bionic alginate (Alg)/α‐tricalcium phosphate (α‐TCP) composite microsphere is developed that mimics both the physical structure and biological activity of natural bone. Structurally, the microspheres feature an organic–inorganic interpenetrating network, making it less prone to collapse and fragmentation compared to pure α‐TCP microspheres. Biologically, the microspheres are modified with Dba Y K Y ‐DM ₅₀ CO ₅₀ , a β‐amino acid polymer mimicking extracellular matrix (ECM) peptides, to promote cell adhesion. Notably, the Alg/α‐TCP composite microspheres enable integrated cell cryopreservation, recovery, and expansion, expanding their potential for downstream bone repair applications. Additionally, in a rat femoral condyle defect model, the composite microspheres exhibit exceptional bone regeneration efficacy, implying a promising strategy in designing materials for minimally invasive bone regeneration therapies.