Multifunctional Recombinant Human Collagen‐Based Janus Membrane to Tailor Cell Microenvironment for Guided Bone Regeneration

Commercially available collagen membranes encounter challenges in guided bone regeneration (GBR) owing to the lack of hierarchical structural design, suboptimal mechanical properties, bacterial infiltration, and limited bioactivity. Herein, a Janus membrane designated as TA@hCJM is developed, featuring a porous surface to augment osteogenic activity and a dense face to preserve barrier functionality. Specifically, the hydrophilic down layer is composed of composite nanofibers integrating recombinant human type I collagen (rhCol I), poly (lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), and tannic acid (TA). This configuration facilitates cellular adhesion, proliferation, and osteogenic differentiation by activating the TGF-β/BMP-Smad signaling pathway. The hydrophobic upper layer consists of a dense PLGA barrier that effectively prevents fibroblast infiltration and maintains a stable regeneration space. Concurrently, TA@hCJM effectively enhances osteogenesis through recruiting stem cells and confers antioxidant and antibacterial properties, facilitating bone regeneration in a favorable microenvironment. An in vivo investigation confirmed that the bone defect area guided by TA@hCJM was completely repaired by generating new bone tissue. Collectively, TA@hCJM offers versatile approaches to fabricating recombinant human collagen-based biomaterials for hard tissue regeneration, as well as effective material design for advanced GBR applications.