Adipose-derived stem cells (ADSCs) loaded gelatin-sericin-laminin cryogels for tissue regeneration in diabetic wounds.

Abstract

Healing in wounds like pressure ulcers, diabetic ulcers, venous ulcers, and arterial insufficiency ulcers is immensely hampered and causes both economic burden and morbidity to patients. These wounds face plethora of hostile conditions like elevated reactive oxygen species (ROS), impaired angiogenesis, senescent fibroblast and deficient stem cells that significantly diminish the probability of self-healing in these wounds. Adipose-derived stem cell therapy (ADSC) presents a promising approach to achieve efficient healing in such cases. To address the complex scenario of chronic wounds, we propose a combinatorial approach of delivering ADSCs on antioxidant gelatin-sericin (GS) scaffolds coated with laminin (GSL), an endothelial basement protein to improve angiogenesis. The synthesized GS scaffolds showed values of compression modulus, pore size, porosity, and the swelling ratio in the range of 65 kPa, 158±48.8 µm, 91.1% ±1.25, and 28±2.5 respectively. DPPH assay revealed GS scaffolds exhibit around 20% more scavenging as against gelatin (G) scaffolds and better protection against free radical assault thus enhancing cell viability and metabolic index of fibroblast cells. Different cells viz fibroblast, keratinocytes and ADSCs cultured on GS scaffolds had better metabolic activity as compared to G scaffolds. Laminin coating onto the scaffolds leads to improved attachment and tube formation of endothelial cells as depicted in scanning electron microscopy images (SEM). Finally, we validated the applicability of the ADSCs loaded laminin-coated GS scaffolds in diabetic ulcer rat model. Hematoxylin & Eosin, Masson s trichrome and Picrosirius red staining showed better regeneration and collagen remodeling in ADSCs loaded GSL scaffolds. Immunostaining of CD31 staining demonstrate enhanced angiogenesis in GSL-ADSC as compared to other groups. Key words: Adipose derived stem cells, cryogels, gelatin-sericin-laminin scaffolds, diabetic wounds, tissue regeneration.