Effect of alkali on konjac glucomannan film and its application on wound healing

Konjac glucomannan (KGM) is widely used in the food industry because of its biocompatibility, nontoxicity, and favorable film-forming ability. However, KGM has been seldom applied to biomaterials for tissue regeneration. In this paper, we investigate the effects of Ca(OH)₂ on KGM film and evaluate its potency as a wound dressing. We successfully prepared Ca(OH)₂-treated KGM film. High Ca(OH)₂ concentrations created rough film surfaces. These rough surfaces resulted from the deposition of nanosized or microsized CaCO_3(s). Compared with commercially available 3M hydrocolloid dressings, dressings with KGM exhibited a more favorable degree of swelling and water vapor transmission rate. The film with a Ca(OH)₂/KGM weight ratio of 2.5 % exhibited the optimal tensile strength and elongation. The results of an in vitro MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] cell viability assay revealed the favorable biocompatibility of KGM films with L929 cells. For antibacterial evaluation, tetracycline-loaded KGM film exhibited strong inhibitory effects against Staphylococcus aureus with a 2.5-cm inhibition zone. In vivo animal studies have indicated that KGM films effectively promote the contractility of wounds, especially at the early healing stage. Histological examinations have also demonstrated that using KGM films to treat wounds enables considerably advanced granulation tissue and epithelial coverage to develop by the 7th and 14th days of treatment. In summary, Ca(OH)₂-treated KGM film could be considered as a promising, novel, biocompatible wound dressing.