Evaluation of the antibacterial effect, cell viability and biodegradation of a new synthetic mucosal wound dressing: an in vitro study

Introduction : In surgical wounds, such as periodontal surgery, the wound dressing can be used to create better conditions for wound healing. None of the existing periodontal wound dressing such as eugenol or Non-eugenol dressing has all ideal features. One of the new approaches for wound dressing is the use of biocompatible scaffolds containing antibacterial agents, so they improve fibroblasts adhesion, growth, proliferation and differentiation and by this way accelerate the repair. The aim of the present study was evaluation of the cell viability and biodegradation of a new synthetic mucosal wound dressing. The perspective of this study is the use of zeolite-chitosan-gelatin (ZCG) scaffold as wound dressing. Methods: Scaffolds were sterilized in alcohol, washed in PBS and then were put in 20 ml vials and 10 mg/ml hen egg white (HEW) lysozyme was added. Vials were incubated in (37 C and 5% CO2/95% air) and media was replaced weekly. In each period of time four scaffolds were dehydrated by alcohol and were dried in vacuum for eight hours and were weighing on 1, 7, 14, 28, 42, 60 day. Human gingival fibroblasts were harvested by 0.25% trypsin EDTA and were seeded at 2*105 densities on scaffold. At following day culture medium (DEME) was removed and scaffolds were washed by PBS then 2% Triton-X 100 (Sigma) was added, after 50 minutes 3mM propidium iodide (PI) (Invitrogen, USA) and 10 mg/ml RNaseA(Invitrogen) was added and fluorescence intensity was measured by microplate reader(Synergy Microplate Reader-BioTek, Germany) at 535 and 617 nm on 1, 5 and 8 day. Data were analysed by two-way ANOVA and Bonferroni. In vitro antibacterial activity of the prepared scaffolds was evaluated by disc diffusion method. According to the recommended standards of National Committee for Clinical Laboratory Standards (NCCLS, 2005), agar disc diffusion method was carried out against Aggregatibacter actinomycetemcomitans(Aa). The scaffold compare with chlorhexidine and kaltostat (a commercial wound dressing). Data were analysed by one way ANOVA. Results: ZCG were more biocompatible than CG scaffolds and supported adhesion and proliferation of human gingival fibroblasts. The highest cell proliferation was in eighth day on ZCG. The difference in mean values on day 1, 5, 8 was 103.2±3.406 (Pvalue<0.0001), 287.200±3.406, (Pvalue< 0.0001), 446.400±3.406 (Pvalue< 0.0001). ZCG scaffold demonstrated more sustainability in all period of time in comparison to CG scaffold. The difference between the mean values were 0.113±0.019 (Pvalue = 0.0001), on day 1, 0.059 ±0.019 (Pvalue = 0.0001) on day 7, 0.107±0.019 (Pvalue = 0.0001) on day 14, 0.040± 0.019 (Pvalue = 0.031) on day 28, 0.110±0.019 (Pvalue = 0.0001) on day 42, 0.079 ±0.019 (Pvalue = 0.0001) on day 60. Neither ZCG scaffold nor Kaltostat have significant antibacterial effect on Aa in comparison to CHX. The mean diameter of inhibition zone difference between ZCG scaffold and Kaltostat was 1.33±0.608 with Pvalue = 0.151 and they were not significantly different. Conclusion: In this work, ZCG scaffold that previously prepared by Houshmand et al demonstrated high viability on human gingival fibroblast. It was also found that this scaffold has favorable sustainability for at least 60 days. Thus, considering its sustainability and cell proliferative properties, it can be an ideal for tissue engineering scaffold as a mucosal wound dressing. So we suggest further evaluation of its properties in clinical trials.