Development of chitosan based hydrogels with marigold flower extract: An innovative, low cost, biodegradable and antimicrobial solution for enhanced wound healing applications

Abstract

Marigold (Tagetes erecta), constitutes a commonly utilized floral resources in craft applications, frequently facing discard despite its intrinsic potential for diverse applications. It is an ingredient in ethno medicines and contains several bioactive compounds, including essential oils, carotenoids, flavonoids, terpenoids, thiophenes, and phenolic compounds. T. erecta flower extract is well-known for its antibacterial, anti-inflammatory, and antioxidant activities, as well as wound-healing effects. Therefore, the present research aims to explore its wound-healing potential by incorporating it into a hydrogel-based matrix. Hydrogel wound dressings could create a moist environment that accelerates wound healing by providing a base for epithelial tissue development, and shielding wounds. For the first time, the chitosan-based herbal hydrogels were prepared by encapsulating the aqueous extract of TEFE using the freeze-thaw method. The flower extract was successfully incorporated into pH-sensitive chitosan herbal gels to deliver the extract to infected wounds while preserving its biological activities. The release kinetics of the hydrogels were evaluated under different environmental conditions to determine the TEFE release behaviour. The hydrogel system demonstrated a prolonged release of the floral extract for up to 7 days. Furthermore, the hydrogel formulation exhibited strong antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans. The TEFE-loaded hydrogels also demonstrated promising antidiabetic potential through inhibition of α-amylase (43.5 %) and α-glucosidase (49.3 %), suggesting applicability in diabetic wound care. The chitosan hydrogels encapsulating TEFE were biodegradable, with remarkably high degradability observed after 21 days of exposure to soil. The MTT assay of the CHS-TEFE herbal hydrogel using mouse L929 cell lines confirmed its non-toxic nature, highlighting its potential as a safe and effective delivery system for managing open skin wounds through localized application.