Controlled release of thymosin beta 4 using a collagen-chitosan sponge scaffold augments cutaneous wound healing and increases angiogenesis in diabetic rats with hindlimb ischemia

Tissue Eng Part A. 2015 Feb;21(3-4):541-9. doi: 10.1089/ten.TEA.2013.0750. Epub 2014 Oct 14.

Abstract

It is important to establish an efficient vascularization for the long-term acceptance of bioengineered skin equivalents treating the cutaneous wounds of diabetic rats with hindlimb ischemia. This study investigates the possible use of a collagen-chitosan sponge scaffold encapsulated with thymosin beta 4 (CCSS-eTβ4), an angiogenic factor, to accelerate cutaneous wound healing in streptozotocin (STZ)-induced diabetic rats with hindlimb ischemia. CCSSs-eTβ4 was fabricated using a freeze-drying method. The scaffolds were analyzed by scanning electron microscopy, swelling and degradation assays, mechanical properties, and scaffolds of 50:50 collagen-chitosan were selected and applied. The controlled release of Tβ4 from the scaffolds elicited localized and prolonged effects over 12 days, as shown by an enzyme-linked immunosorbent assay (ELISA). In vivo, CCSSs-eTβ4 improved diabetic cutaneous wound healing, with faster wound reepithelialization, better dermal reorganization, and higher wound vascularization. Furthermore, CCSSs-eTβ4 downregulated inflammatory genes and upregulated angiogenic genes in the wound tissue. Significant increases in CD31-positive endothelial cells and new vessel density were also observed. In vitro, Tβ4 increased the migratory and proliferative activity of high glucose (HG)-treated human umbilical vein endothelial cells (HUVECs). Meanwhile, we found that Tβ4 could promote HG-treated HUVECs migration and improve angiogenesis by activation of the VEGF/AKT pathway. Overall, these findings demonstrated the promising potential of CCSSs-eTβ4 to promote more effective wound healing and suggest its possible application for diabetic cutaneous wound treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inducing Agents / administration & dosage
  • Angiogenesis Inducing Agents / chemistry
  • Animals
  • Bandages
  • Biocompatible Materials / chemical synthesis
  • Chitosan / chemistry
  • Collagen / chemistry
  • Delayed-Action Preparations / administration & dosage
  • Delayed-Action Preparations / chemical synthesis*
  • Diabetic Foot / therapy*
  • Diffusion
  • Equipment Design
  • Equipment Failure Analysis
  • Male
  • Materials Testing
  • Neovascularization, Physiologic / drug effects*
  • Rats
  • Rats, Wistar
  • Skin, Artificial*
  • Thymosin / administration & dosage*
  • Thymosin / chemistry
  • Tissue Scaffolds
  • Treatment Outcome
  • Wound Healing / drug effects*

Substances

  • Angiogenesis Inducing Agents
  • Biocompatible Materials
  • Delayed-Action Preparations
  • thymosin beta(4)
  • Thymosin
  • Collagen
  • Chitosan