Synthesis and characterization of collagen/calcium phosphate scaffolds incorporating antibacterial agent for bone tissue engineering application

In the present study, we developed a novel niosomal nanocarrier embedded into a collagen/beta- tricalcium phosphate (Col/beta-TCP) scaffold for the local delivery of thymol as a natural anti-bacterial reagent. The niosomal Col/beta-TCP (N-Col/beta-TCP) scaffolds with different weight ratios of beta-TCP to Col were prepared by freeze-drying. The antimicrobial activities of the prepared samples against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were assessed by agar diffusion method. The release profile of niosomal thymol from the optimized composite scaffolds showed a sustained profile where 66% of the loaded thymol was released over 30 days. The compressive modulus of niosome added scaffolds with an equal ratio of beta-TCP and Col was calculated as 972 +/- 1.3KPa. This scaffold showed significantly higher values of cell viability (as evaluated by an MTT assay) against L929 fibroblasts than a scaffold without niosomal thymol after 24 and 72 h. Among synthesized samples, Col/beta-TCP1 showed the greatest effectiveness of anti-bacterial activity toward Gram-positive and Gram-negative bacteria with higher activity against Gram-positive ones. The results of this study highlight the potential of niosomal-thymol loaded Col/beta-TCP1 scaffold as an anti-bacterial bone substitute for possible osteomyelitis treatment.