Honey-based hydrogel: In vitro and comparative In vivo evaluation for burn wound healing

Abstract

Honey was used to treat wounds since ancient times till nowadays. The present study aimed at preparing a honey-based hydrogel and assay its antimicrobial properties and wound healing activity; in-vitro and in-vivo. Topical honey hydrogel formulations were prepared using three honey concentrations with gelling agents; chitosan and carbopol 934. The prepared formulae were evaluated for pH, spreadability, swelling index, in-vitro release and antimicrobial activity. The pH and spreadability were in the range of 4.3-6.8 and 5.7-8.6 cm, respectively. Chitosan-based hydrogel showed higher in-vitro honey release with diffusional exponent 'n ≤ 0.5 indicates Fickian diffusion mechanism. Hydrogel formulae were assessed for in-vitro antimicrobial activity using Disc Diffusion antibiotic sensitivity test against common burn infections bacteria; Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia and Streptococcus pyogenes. The 75% honey-chitosan hydrogel showed highest antimicrobial activity. This formula was tested for in-vivo burn healing using burn-induced wounds in mice. The formula was evaluated for burn healing and antibacterial activities compared to commercial product. 75% honey-chitosan hydrogel was found to possess highest healing rate of burns. The present study concludes that 75% honey-chitosan hydrogel possesses greater wound healing activity compared to commercial preparation and could be safely used as an effective natural topical wound healing treatment.

Figure 1

Honey release profile from prepared hydrogel formulae.

Figure 2

Disc Diffusion antibiotic sensitivity test against Staphylococcus aureus. (a) Pure honey, (b) Chitosan hydrogel, (c) F3 (75% honey + chitosan hydrogel).

Figure 3

Mean wound diameter (mm ± SD). N: negative control, normal saline, P: positive control, silver sulphadiazine, H: pure honey, F3: 75% honey-chitosan formula. *F3 significantly effective than either control, P or H (p < 0.001).

Figure 4

Representative photomicrographs of tissue sections stained with H&E. (a) Day 1 directly after induced third degree burn showing necrosis of the epidermal and dermal layers in focal manner with inflammatory cells infiltration in subcutaneous tissue and musculature (16x mag). (b) Day 9 after burn. Skin of mice treated with silver sulphadiazine showing focal necrosis of the epidermis with acanthosis in the adjacent one and inflammatory cells infiltration in the underlying dermis and subcutaneous tissue (16x mag). (c) Day 9 after burn. Skin of mice treated with pure honey showing few newly formed blood capillaries and few fibroblastic cell proliferation as granulation tissue in subcutaneous tissue with inflammatory cell infiltration (40x mag). (d) Day 9 after burn. Skin of mice treated with honey 75%-chitosan formula showing regeneration of the epidermal layer with separation of the necrosed areas as scales and formation of new blood capillaries. (40x mag).