Increased Elasticity Modulus of Polymeric Materials Is a Source of Surface Alterations in the Human Body.

Matthias Kapischke,Igor Erlichman,Alexandra Pries

doi:10.3390/jfb12020024

Abstract

The introduction of alloplastic materials (meshes) in hernia surgery has improved patient outcome by a radical reduction of hernia recurrence rate, but discussion about the biocompatibility of these implanted materials continues since observations of surface alterations of polypropylene and other alloplastic materials were published. This study intends to investigate if additives supplemented to alloplastic mesh materials merge into the solution and become analyzable. Four polypropylene and one polyester alloplastic material were incubated in different media for three weeks: distilled water, saline solution, urea solution, formalin, and hydrogen peroxide. No swelling or other changes were observed. Infrared spectroscopy scanning of incubated alloplastic materials and NMR studies of extracted solutions were performed to investigate loss of plasticizers. The surface of the mesh materials did not show any alterations independent of the incubation medium. FT-IR spectra before and after incubation did not show any differences. NMR spectra showed leaching of different plasticizers (PEG, sterically hindered phenols, thioester), of which there was more for polypropylene less for polyester. This could be the reason for the loss of elasticity of the alloplastic materials with consecutive physically induced surface alterations. A mixture of chemical reactions (oxidative stress with additive leaching from polymer fiber) in connection with physical alterations (increased elasticity modulus by loss of plasticizers) seem to be a source of these PP and PE alterations.

Highlights

The implantation of alloplastic materials such as polypropylene (PP) or polyester (PE)in hernia repair is currently the surgical standard [1]
It is incontestable that the use of these alloplastic materials in hernia repair is superior to non-mesh repair regarding the hernia recurrence and the reoperation rate [2]
The reasons of the surface alterations are assessed differently; they range from obviously water triggered swelling and modifications due to shrinking of the isolated PP fiber [5] to the impact of lysosomal enzymes to the formation of free radicals [6,8] and oxidative stress [9]

Summary

Introduction

The implantation of alloplastic materials such as polypropylene (PP) or polyester (PE)in hernia repair is currently the surgical standard [1]. There is the fact that these alloplastic materials, which are supposed to be clinically inert [3,4], are often described as showing structural changes [5,6,7,8]. The aging processes of polymers is segmented into chemical and physical processes. Under the conditions in the human organism, the complexity of the process is not comprehended; traditionally, the chemical alteration process is the focus of interest. Within this complex occurrence, polymers undergo random chain scission, which induces embrittlement. Even though researchers had been mostly focused on chemical aspects of aging, it is noteworthy that a ductile–brittle transition can occur without chemical degradation in polymers submitted to mechanical loads [13]

Results

Discussion

Conclusion