κ/β-Carrageenan oligosaccharides promoting polarization of LPS-activated macrophage and their potential in diabetes wound healing.

Here we prepared a low-degree-sulfated κ/β-carrageenan oligosaccharide (L-DS-KOS) by DMSO-methanol desulfation method, and fabricated a sponge dressing for the wound healing of diabetic rats. The immunomodulatory effects of L-DS-KOS on M1-like macrophages were evaluated. Results showed that L-DS-KOS could effectively promote the secretion of anti-inflammatory factors and accelerate polarization of LPS-activated macrophages from M1 to M2 type. The gross examination result showed that the sponge dressing with the mass ratio of L-DS-KOS: collagen = 3: 7 could effectively accelerate the repair process of the full-thickness excisional wound in diabetic rats; and H&E and Masson staining results disclosed that the L-DS-KOS/collagen dressing could better shorten the inflammation period of the wound site, and improve the process of collagen deposition and epithelial formation, thereby promote the repair of skin wounds in diabetic rats. These results demonstrate that L-DS-KOS has potential to be used as a new type of immunomodulatory biomaterial for diabetic wound dressings.