Chitosan-based polyelectrolyte complex scaffolds with antibacterial properties for treating dental bone defects

The aim of this study was to develop an antibacterial polyelectrolyte complex (PEC) scaffold for treating dental bone defects. The PEC scaffold was composed of chitosan (CS), γ-polyglutamic acid (γ-PGA), and carboxy-methyl-cellulose (CMC). The resulted network structures formed via electrostatic crosslinking were characterized by using FTIR, gel content, equilibrium swelling ratio, volume change, and SEM test. The antibacterial property, cell cytotoxicity, and in vivo biocompatibility tests were conducted according to an agar diffusion method, ISO10993-5, and ISO 10993-6, respectively. The resulted specimens showed an interconnected pore structure with pore sizes ranging 100-500 μm. The equilibrium swelling ratio, volume change, and antibacterial property were inversely proportional to the gel content. The PEC-2 scaffold composed of 8 wt.% CS, and 2 wt.% γ-PGA + 2 wt.% CMC had more-suitable gel properties (gel content of 55.3 ± 1.1 wt.% and volume change of 97.7 ± 1.4 v/v%) with inhibition zones of 14.4 ± 0.3 mm for Escherichia coli and 13.0 ± 0.7 mm for Staphylococcus aureus. The cytotoxicity and cell attachment tests of the PEC scaffolds showed satisfactory cell compatibility. Moreover, the in vivo biocompatibility test of the PEC scaffolds revealed little foreign body reaction. For this reason, the newly developed antibacterial PEC scaffold may be a good alternative for dental applications.