Fabrication, characterization and evaluation of the efficacy of gelatin/hyaluronic acid microporous scaffolds suffused with aloe-vera in a rat burn model

Abstract

Burn induced injuries are commonly encountered in civilian and military settings, leading to severe morbidity and mortality. Objective of this study was to construct microporous bioactive scaffolds of gelatin-hyaluronic acid suffused with aloe-vera gel (Gela/HA/AvG), and to evaluate their efficacy in healing partial-thickness burn wounds. Scaffolds were characterized using Fourier transform-infrared spectroscopy, Scanning electron microscopy, and Thermo-gravimetric analysis to understand intermolecular interactions and morphological characteristics. In-vitro fluid uptake ability and hemolytic index of test scaffolds were also determined. In-vitro collagenase digestion was done to assess biodegradability of scaffolds. Wound retraction studies were carried out in Sprague Dawley rats inflicted with partial-thickness burn wounds to assess and compare efficacy of optimized scaffolds with respect to negative and positive control groups. In-vivo gamma scintigraphy using Technetium-99m labeled Immunoglobulin-G ( 99m Tc-IgG) as imaging agent was also performed to validate efficacy results. Histological and immunohistochemical comparison between groups was also made. Scaffolds exhibited mircoporous structure, with pore size getting reduced from 41.3 ± 4.3 µm to 30.49 ± 5.7 µm when gelatin conc. was varied from 1% to 5%. Optimized test scaffolds showed sustained in-vitro swelling behavior, were biodegradable and showed hemolytic index in range of 2.4–4.3%. Wound retraction study along with in-vivo gamma scintigraphy indicated that Gela/HA/AvG scaffolds were not only able to reduce local inflammation faster but also accelerated dermis regeneration. Immunohistochemical analysis, in terms of expression levels of epidermal growth factor and fibroblast growth factor-2 also corroborated in-vivo efficacy findings. Gela/HA/AvG scaffolds, therefore, can potentially be developed into an effective dermal regeneration template for partial-thickness burn wounds.