Hydrophilic Polydopamine (hpda) Fueled Bioglue Enhances Tissue Adhesion and Promotes Healing of Avascular Meniscus Tears

Avascular meniscus tears exhibit minimal intrinsic healing and frequently progress to joint degeneration because of limited vascularity, poor biological repair capacity, and inadequate restoration of tissue-level mechanical continuity. Here, we report a hydrophilic polydopamine (hPDA) fueled bioglue platform that overcomes the aqueous insolubility limitations of conventional polydopamine (PDA) and enables functional repair of avascular meniscus injuries. Water soluble hPDA was synthesized through controlled depolymerization and recrystallization, yielding monomeric and oligomeric species rich in catechol, amine, and hydroxyl functionalities. Incorporation of hPDA into fibrin bioglues significantly improved both bulk mechanical and interfacial adhesive properties, producing 515-525% increases in lap-shear modulus, 165-190% increases in adhesive strength, up to 175% increases in compressive modulus, and approximately 176% increases in compressive strength relative to fibrin controls, while also improving degradation stability over 14 days. In contrast to genipin-mediated covalent crosslinking, hPDA primarily enhanced mechanical performance through catechol-mediated intermolecular interactions, improved energy dissipation, and reinforced interfacial load transfer. hPDA exhibited excellent cytocompatibility in both 2D and 3D cultures. In a bovine avascular meniscus explant model, hPDA fueled bioglues promoted tissue integration and aligned collagen remodeling, restoring interfacial mechanics with a 482-582% increase in tensile (pull-out) modulus and up to 152-285% higher pull-out strength after 6 weeks. These findings establish hPDA as a versatile bioadhesive building block with strong potential for repairing avascular meniscus tears and other mechanically demanding connective tissues.