Fabrication of a Vitamin B12-Loaded Carbon Dot/Mixed-Ligand Metal Organic Framework Encapsulated within the Gelatin Microsphere for pH Sensing and In Vitro Wound Healing Assessment

Abstract

Bacterial invasion is a serious concern during the wound healing process. The colonization of bacteria is mainly responsible for the pH fluctuation at the wound site. Therefore, the fabrication of a proper wound dressing material with antibacterial activity and pH monitoring ability is necessary to acquire a fast healing process. Therefore, this work is dedicated to designing a vitamin B12-loaded gelatin microsphere (MS) decorated with a carbon dot (CD) metal−organic framework (MOF) for simultaneous pH sensing and advanced wound closure application. The resultant MS portrayed a high specific surface area and a hierarchically porous structure. Furthermore, the surface of the resultant MS contained numerous carboxyl groups and amine groups whose deprotonation and protonation with the pH alternation are accountable for the pH-sensitive properties. The vitamin B12 release study was speedy from the MOF structure in an acidic medium, which was checked by gelatin coating, and a controlled drug release behavior was observed. The system showed excellent cytocompatibility toward the L929 cell line and remarkable antibacterial performance against Gramnegative Escherichia coli and Gram-positive Staphylococcus aureus. Furthermore, the combined effect of Zn 2+ , the imidazole unit, and CDs produces an outstanding bactericidal effect on the injury sites. Finally, the in vitro wound model suggests that the presence of the vitamin B12-loaded gelatin MS accelerates the proliferation of resident fibroblast L929 cells and causes tissue regeneration in a time-dependent manner. The relative wound area, % of wound closure, and wound healing speed values are remarkable and suggest the requirement for assessing the response of the system before exploiting its prospective in vivo application.

Facile synthesis of zinc acetate/niacin MOFs for use in wound healing

“…Local delivery of B vitamins has shown beneficial effects on the wound healing process [9,10]. Vitamin B3, also known as niacin or nicotinic acid, has been reported by several groups to effectively support wound healing [9,11,12].…”

“…Silver MOFs have substantial antimicrobial properties [18]. However, silver is expensive and may cause environmental hazards which makes zinc a better alternative as a nontoxic, low-cost metal with antibacterial properties, making it an attractive candidate for wound healing applications [10,19].…”