Biomimetic hybrid porous scaffolds immobilized with platelet derived growth factor-BB promote cellularization and vascularization in tissue engineering.

Development of hybrid scaffolds with synergistic combination of growth factor is a promising approach to promote early in vivo wound repair and tissue regeneration. Here, we show the rapid wound healing in Wistar albino rats using biomimetic collagen-poly(dialdehyde) guar gum based hybrid porous scaffolds covalently immobilized with platelet derived growth factor-BB. The immobilized platelet derived growth factor in the hybrid scaffolds not only enhance the total protein, collagen, hexosamine, and uronic acid contents in the granulation tissue but also provide stronger tissues. The wound closure analysis reveal that the complete epithelialization period is 15.4 ± 0.9 days for collagen-poly(dialdehyde) guar gum-platelet derived growth factor hybrid scaffolds, whereas it is significantly higher for control, collagen, collagen- poly(dialdehyde) guar gum and povidine-iodine treated groups. Further, the histological evaluation shows that the immobilized platelet derived growth factor in the hybrid scaffolds induced a more robust cellular and vascular response in the implanted site. Hence, we demonstrate that the collagen-poly(dialdehyde) guar gum hybrid scaffolds loaded with platelet derived growth factor stimulates chemotactic effects in the implanted site to promote rapid tissue regeneration and wound repair without the assistance of antibacterial agents.

Highly biocompatible collagen-Delonix regia seed polysaccharide hybrid scaffolds for antimicrobial wound dressing.

Biomaterials based entirely on biological resources are ideal for tissue engineering applications. Here we report the preparation of hybrid collagen scaffolds comprising gulmohar seed polysaccharide (GSP) and cinnamon bark extract as cross-linking agent. (1)H NMR spectrum of GSP confirms the presence of galactose and mannose in the ratio of 1:1.54, which was further corroborated using FT-IR. The hybrid scaffolds show better enzyme and thermal stability in contrast to pure collagen scaffold probably due to weak interactions from GSP and covalent interaction through cinnamaldehyde. Gas permeability and scanning electron microscopic analysis show that the porosity of the hybrid scaffolds is slightly reduced with the increase in the concentration of GSP. The infrared and circular dichroic spectral studies show that the secondary structure of the collagen did not change after the interaction with GSP and cinnamaldehyde. The hybrid scaffolds stabilized with cinnamaldehyde show good antimicrobial activity against the common multi-drug resistant wound pathogens. These results suggest that the prepared hybrid scaffolds have great potential for antimicrobial wound dressing applications.

Melatonin in functionalized biomimetic constructs promotes rapid tissue regeneration in Wistar albino rats.

The development of hybrid scaffolds mimicking the extracellular matrix with bioactive factors has great potential to regenerate tissues in tissue engineering and wound-healing applications. Herein, poly(dialdehyde) gum acacia was synthesized by the selective oxidation of gum acacia and was blended with collagen and melatonin to fabricate biomimetic hybrid scaffolds. The inclusion of poly(dialdehyde) gum acacia improved the stability of collagen and immobilized the melatonin in the hybrid scaffolds. The prepared hybrid scaffolds showed significant biocompatibility when cultured with the Swiss 3T6 mouse fibroblast cell lines in vitro. When subjected to open excisional skin wounds in Wistar albino rats in vivo, the collagen-poly(dialdehyde) gum acacia-melatonin hybrid scaffolds accelerated re-epithelialization and collagen deposition. The results indicate that the melatonin-immobilized hybrid scaffold promotes rapid tissue regeneration and wound repair owing to its antioxidant and anti-inflammatory properties, thereby demonstrating its potential for application in burns and chronic wounds.