Investigation of BTZ@OSA-GelMA-BCP composite bone scaffold

Large-scale bone defects resulting from trauma, infection, aging, tumors, and other diseases present significant clinical challenges. Current treatment modalities primarily involve surgical intervention, chemotherapy, and radiotherapy. However, conventional bone repair materials exhibit limitations in addressing tumor-associated defects, including inadequate drug loading capacity, uncontrolled release kinetics, and insufficient mechanical adaptability. To address these deficiencies in existing bone repair materials, we developed a novel composite bone scaffold utilizing a biphasic calcium phosphate (BCP) osteoconductive matrix. This matrix was integrated with polyacrylamide-modified gelatin (GelMA) hydrogel to enhance mechanical strength and oxidized sodium alginate (OSA) hydrogel containing pH-sensitive acylhydrazone bonds. The incorporation of the hydrogels significantly increased the compressive strength of the composite scaffold from 1.920 MPa to 2.515 MPa. Furthermore, the scaffold was physically adsorbed with the anti-tumor drug bortezomib (BTZ), demonstrating sustained release under simulated physiological conditions (pH 7.4). Notably, the release rate accelerated under acidic conditions that mimic the tumor microenvironment (pH 5.4 and 6.8).