A dual-modified glucomannan polysaccharide selectively sequesters growth factors for skin tissue repair

Artificial dermal matrixes (ADMs) are valuable clinical options for treating large soft tissue defects, but their suboptimal bioactivities compared with the real tissue limit their therapeutic potential. For example, glycosaminoglycan (GAG) polysaccharides in the native skin vitally and differentially regulate endogenous growth factors (GFs) to maintain tissue homeostasis. However, the GAG used in the current ADMs has often lost such delicate regulation. Here, we developed a novel polysaccharide-based ADM that can promote skin tissue repair through selective modulation of specific pro-healing GFs. First, we prepared a plant-derived backbone of glucomannan (named BSP) - representing the two dominant monosaccharide components in the human body - in mass and homogenic quality. Then, we modified this backbone with sulfate and acetyl groups in a controlled manner to yield an optimized BSP derivative (S^MA^L-BSP) as a main composition to generate a new ADM. In vitro, S^MA^L-BSP enabled the ADM to selectively sequester pro-angiogenic GFs of VEGF-A and FGF-2 in situ for stimulating endothelial cell growth. Moreover, the addition of the acetyl group induced macrophages to secrete nitric oxide (NO) with antibacterial activities. Further in vivo tests in a rat model of full-thickness skin wounds indicated that S^MA^L-BSP ADM could sequester GFs in situ to promote angiogenesis and thus tissue regeneration, with superior effects than conventional chondroitin sulfate-based ADM, while showing no adverse effects often associated with animal-derived products. Our study represents a novel strategy for ADM design, targeting selective GF sequestration towards optimal skin tissue regeneration.