Free radical scavenging injectable hydrogels for regenerative therapy

Mater Sci Eng C Mater Biol Appl. 2017 Feb 1:71:100-110. doi: 10.1016/j.msec.2016.09.087. Epub 2016 Sep 30.

Abstract

Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy.

Keywords: Antioxidant; Free radical scavenging; Injectable hydrogel; Pathological free radicals; Regenerative therapy.

MeSH terms

  • Animals
  • Cell Line
  • Free Radical Scavengers* / chemical synthesis
  • Free Radical Scavengers* / chemistry
  • Free Radical Scavengers* / pharmacokinetics
  • Free Radical Scavengers* / pharmacology
  • Hydrogels* / chemical synthesis
  • Hydrogels* / chemistry
  • Hydrogels* / pharmacokinetics
  • Hydrogels* / pharmacology
  • Myoblasts, Cardiac / cytology
  • Myoblasts, Cardiac / metabolism*
  • Rats
  • Regenerative Medicine / methods*

Substances

  • Free Radical Scavengers
  • Hydrogels