Hydrogel Based on Decellularized Bovine Trabecular Extracellular Matrix Enriched with Type I Collagen

Biomaterials are increasingly important in addressing the demand for biomimetic, biocompatible, and biodegradable materials for tissue replacement, treatment, or coexistence. Biocomposites enhance chemical and mechanical properties, supporting biological integration and mechanical stability at implantation sites. This study aimed to develop a thermosensitive biocomposite hydrogel using a decellularized extracellular matrix (ECM) from bovine trabecular bone and type I collagen from bovine tendon. Tendon-derived collagen increased total collagen concentration, improving cross-linking. Bovine bones were fragmented, decellularized, lyophilized, and pulverized. Type I collagen was extracted from tendons via solubilization in acetic acid, salt precipitation, and dialysis. ECM digestion was conducted in 0.01 N HCl with pepsin (1:10 ratio) at 37 °C for 96 h. The final collagen concentration was set at 10 mg/mL, with ECM-to-tendon collagen at a 1:10 ratio. Gelation was induced by temperature and pH changes. The ECM-collagen solution was neutralized (pH 7.0-7.6) using 0.1 M NaOH (1/10 digestion volume) and 10× PBS (1/9 digestion volume) to form a pregel, which was incubated at 37 °C for gelation. Gelation time, analyzed by turbidimetry at 405 nm, showed completion in ∼50 min. Collagen incorporation was 96.7%, while glycosaminoglycans (GAGs) incorporation reached 109%. Scanning electron microscopy (SEM) confirmed a porous, reticulated structure. These results indicate the successful incorporation of bone ECM components, thermosensitivity, and potential for Tissue Engineering and Regenerative Medicine applications in bone repair.