Influence of Poly(Ethylene Glycol) End Groups on Poly(Ethylene Glycol)-Albumin System Properties as a Potential Degradable Tissue Scaffold.

Robyn Overby,Dale Feldman

doi:10.3390/jfb10010001

Abstract

Chronic dermal lesions, such as pressure ulcers, are difficult to heal. Degradable tissue scaffold systems can be employed to serve as a provisional matrix for cellular ingrowth and facilitate regenerative healing during degradation. Degradable regenerative tissue scaffold matrices can be created by crosslinking albumin with functionalized poly(ethylene glycol) (PEG) polymers. The purpose of this study was to evaluate the stability of PEG-albumin scaffold systems formed using PEG polymers with three different functionalized end chemistries by quantifying in vitro system swellability to determine the most promising PEG crosslinking polymer for wound healing applications. Of the three polymers evaluated, PEG-succinimidyl glutarate (SG) exhibited consistent gelation and handling characteristics when used as the crosslinking agent with albumin. PEG-SG polymers were identified as an appropriate synthetic crosslinking moiety in a PEG-albumin scaffold system, and further in vitro and in vivo evaluation of this scaffold system is merited.

Highlights

Chronic skin wounds, such as pressure ulcers, are hard to heal due to their typical lack of adequate nutrient support, mechanical load, contamination, and underlying tissue pathology [1]
poly(ethylene glycol) (PEG)-MAL2 samples would not cure under any circumstances over any length of time
Curing problems were first attributed to the pH of the N-2-Hydroxyethylpiperazine-N’-2-ethanesulfonic acid (HEPES) buffer system since both Roberts and Veronese reported higher activity in milder or neutral conditions that collectively ranged between 6 and 8.5 pH [29,30]. This system’s inability to gel, was not dependent on the pH of the HEPES buffer used to solvate the PEG since the PEG-MAL2-albumin system still did not cure in any circumstances after any period of time when the pH was lowered to levels of 5.0, 6.0, 7.0, and 8.0 in an effort to increase activity

Summary

Introduction

Chronic skin wounds, such as pressure ulcers, are hard to heal due to their typical lack of adequate nutrient support, mechanical load, contamination, and underlying tissue pathology [1]. The medical resource, time, societal, and financial burden of these wounds is high [2]. The annual incidence of pressure ulcers in the United States is approximately 2.5 million patients with associated costs exceeding US$11 billion/year [2,3,4]. Medicare and medicaid are the primary payers in over 85% of the hospital stays associated with pressure ulcers; the taxpayer burden is high [3]. Pressure ulcers associated with hospitalizations are increasingly common with the incidence increasing nearly 80% between 1993 and 2006 [3]. Chronic wound rates will continue to rise due to an aging population, the prevalence of medically complicating conditions like diabetes and obesity, and the volume of surgical procedures performed annually [2]

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