Abstract
There has been a significant increase in the demand of polymeric scaffolds with promising affects in bone regeneration. However, inflammation is still a problem in transplantations to overcome with local antibiotic therapy. In this study, it is aimed to develop a functional POSS nanocage reinforced chitosan scaffold (CS/POSS) coated with drug loaded chitosan composite nanospheres to provide a controlled antibianyiotic delivery at the defect site. Gentamicin and vancomycin were selected as model antibiotic drugs. Drug loaded nanospheres were fabricated with electrospray method and characterized in terms of morphology, hydrodynamic size, surface charge, FT-IR, in vitro drug release, antimicrobial activity and cytotoxicity. CS/POSS scaffolds were fabricated via lyophilisation and characterized with mechanic, swelling test, SEM and micro CT analyses. Positively charged nanospheres with uniform morphology were obtained. High drug encapsulation efficiency (80–95%) and sustained release profile up to 25 days were achieved with a cumulative release of 80–90%. In addition, the release media of the nanospheres (in 6 hours, 24 hours and 25 days of incubation period) showed a strong antimicrobial activity against S.aureus and E.coli, and did not show any cytotoxic effect to 3T3 and SaOS-2 cell lines. CS/POSS scaffolds were obtained with high porosity (89%) and 223.3±55.2μm average pore size. POSS reinforcement increased the compression modulus from 755.7 to 846.1Pa for 10 % POSS addition. In vitro studies of nanosphere coated bilayer scaffolds have showed high cell viability. Besides ALP activity results showed that POSS incorporation significantly increased the ALP activity of Saos-2 cells cultured on the scaffold. In conclusion, these composites can be considered as a potential candidate in view of its enhanced physico-chemical properties as well as biological activities for infection preventive bone tissue engineering applications.
