Integration of dual drugs into a collagen scaffold by a combination of apatite coating and impregnation with apatite particles for periodontal regeneration

Bioresorbable porous scaffolds capable of promoting osteoregeneration while preventing bacterial infection are needed for regenerative periodontal therapy. Previously, a porous collagen sponge coated with low-crystalline apatite has been shown to possess superior bioresorption and osteogenic properties compared to the uncoated sponge. In this study, we integrated osteogenic and antibacterial dual drugs into the sponge utilizing two types of apatite matrices to achieve further functionalization. First, the collagen sponge was coated with apatite loaded with an osteogenic drug, L-ascorbic acid 2-phosphate (AS), using a metastable supersaturated calcium phosphate (CaP) solution supplemented with AS. Second, the coated sponge was impregnated with apatite particles loaded with an antibacterial drug, ciprofloxacin (CF), which were fabricated using a labile supersaturated CaP solution supplemented with CF. The resulting dual drug-immobilized sponge demonstrated biological activities arising from both AS and CF; it enhanced proliferation of osteoblastic MC3T3-E1 cells and exhibited antibacterial activity against the oral bacterium Actinomyces naeslundii. The proposed technique to fabricate multifunctional scaffolds would offer a solution to provide more effective, patient-tailored regenerative periodontal therapy.