Multifunctional stimuli-responsive self-healing polyvinyl alcohol/tannic acid/thyme-honey/aloe vera hydrogel as promising antibacterial drug delivery platforms: Physicochemical and in vitro biological assays

Abstract

The utilization of hydrogels in biomedical applications has been on the rise due to their capability to create a moist wound environment and composite with a diverse range of organic and mineral compounds. Our objective was to prepare a pH-responsive system with self-healing and excellent antibacterial properties, capable of releasing active agents at the wound site. Polyvinyl alcohol/tannic acid/thyme-honey/aloe vera hydrogels were synthesized through a freeze-thaw method and characterized for structural, chemical, morphological, antibacterial, and cytotoxicity properties. The hydrogels exhibited remarkable mechanical properties, including tensile strength ranging from 2.51 to 331.44 kPa and compression strength from 2.55 to 16.54 kPa, with viscoelastic behavior suitable for various body tissues. They demonstrated an average healing efficiency of 81 % within 10 min, enduring mechanical stress commonly encountered in wound dressings. The study evaluated their swelling behavior and pH responsiveness, revealing their potential for maintaining a well-hydrated wound environment. The release profiles of tannic acid, thyme-honey, and aloe vera were 82 %, 100 %, and 88 % within 23 days, respectively. The hydrogels demonstrated outstanding antibacterial efficacy, with an average inhibition rate exceeding 98 % against both E. coli and S. aureus, and up to 99 % with thyme-honey and aloe vera, enhancing cell proliferation capacity. Overall, the samples are non-toxic, antibacterial, and cost-effective, making them suitable for wound healing and drug delivery.