Do bioresorbable polyesters have antimicrobial properties?

Lukas Gritsch,Wolfgang H. Goldmann,Christopher Lovell,Aldo R. Boccaccini

doi:10.1007/s10856-017-6021-5

Abstract

Biodegradable and bioresorbable polyesters (BBPEs) are a widespread class of aliphatic polymers with a plethora of applications in the medical field. Some reports speculate that these polymers have intrinsic antibacterial activity as a consequence of their acidic degradation by-products. The release of organic acids as a result of the hydrolytic degradation of BBPEs in vivo and the resulting pH drop could be an effective inhibitor of the growth of pathogens in the local environment adjacent to BBPE-based devices. However, there is no clear and conclusive evidence in the literature concerning the antibacterial activity of BBPE to support or refute this hypothesis. In this communication we address this point through an assessment of the antibacterial properties of six well-established commercially available BBPEs. Agar diffusion assays and optical density measurements at 600 nm were performed on all the polymer samples to characterize the growth of bacteria and any potential inhibition over an incubation period of 24 h. The results indicated that BBPEs do not possess an intrinsic and immediate antibacterial activity, which is consistent with the clear mismatch between the time-scales for bacterial growth and the rate of degradation of the polyesters.Graphical abstract

Highlights

Biodegradable and bioresorbable polyesters (BBPEs) possess numerous beneficial properties, which make them suitable for numerous medical applications such as surgical sutures, orthopedic clips, screws and staples, stents, tissue engineering scaffolds, coatings, and drug delivery vehicles [1, 2]
BBPEs degrade through a hydrolytic process to form by-products, which are metabolized by the body through physiological pathways [3, 4]
Films of six different commercially available BBPEs were prepared by solvent casting

Summary

Introduction

Biodegradable and bioresorbable polyesters (BBPEs) possess numerous beneficial properties (e.g., tailorable mechanical properties, tunable degradation in contact with biological fluids, high availability at competitive costs, and drug carrying/delivering capability), which make them suitable for numerous medical applications such as surgical sutures, orthopedic clips, screws and staples, stents, tissue engineering scaffolds, coatings, and drug delivery vehicles [1, 2]. BBPEs degrade through a hydrolytic process to form by-products, which are metabolized by the body through physiological pathways [3, 4]. Since these by-products are acidic (e.g., lactic acid), it has been proposed that the degradation might result in a drop of the local pH below 4, inhibiting the growth of pathogens [2, 5, 6].

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