Combining in the melt physical and biological properties of poly(caprolactone) and chlorhexidine to obtain antimicrobial surgical monofilaments

Abstract

Bacterial infections on a sutured wound represent a critical problem, and the preparation of suture threads possessing antimicrobial properties is valuable. In this work, poly(caprolactone) (PCL) monofilaments were compounded at the concentration of 1, 2 and 4 % (w/w), respectively, to the antiseptic chlorhexidine diacetate (CHX). The incorporation was carried out in the melt by a single-step methodology, i.e. "online" approach. Mechanical tests revealed that the incorporation of CHX does not significantly change tensile properties of PCL fibres as the thermal profile adopted to prepare the compounded fibres does not compromise the antibacterial activity of CHX. In fact, CHX confers to compounded PCL fibres' antimicrobial property even at the lowest CHX concentration as revealed by microbiological assays performed on Escherichia coli, Micrococcus luteus and Bacillus subtilis strains. The scanning electron microscope micrographs and energy-dispersive X-ray analysis of compounded threads revealed that CHX is uniformly distributed on fibre surface and that the overall amount of superficial CHX increases by increasing compounded CHX concentration. This distribution determines a biphasic CHX release kinetics characterized by an initial rapid solubilisation of superficial CHX micro-crystals, followed by a slow and gradual release of CHX incorporated in the bulk. Interestingly, the compounded threads did not show any toxic effect compromising cell viability of human fibroblasts in vitro, differently from that observed using an equal amount of pure CHX. Thus, this study originally demonstrated the effectiveness of an "online" approach to confer antimicrobial properties to an organic thermoplastic polymeric material commonly used for medical devices.

PHB-PEO electrospun fiber membranes containing chlorhexidine for drug delivery applications

“…This drug has been widely used in a largely range of applications due to its antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi, and non-toxicity toward mammalian cells [11,12]. It is used in several products for oral protection and, in general, for dentistry applications due to its antiseptic and disinfectant action on wounds [13]. Various studies [11,12,[14][15][16] have been conducted on CHX release, however, only a few works are devoted to CHX release with electrospun fibers.…”

Mechanical behavior of polylactic acid/polycaprolactone porous layered functional composites

“…The real porosity was calculated as the reciprocal of the ratio between the apparent densities of the laminate and of the non-porous polymeric material, by using expression (2). It expresses the ratio between the empty volume and the overall volume of the laminate (empty þ full).…”

Incorporation of an Antibiotic in Poly(Lactic Acid) and Polypropylene by Melt Processing

“…The incorporation of antimicrobials, or other molecules, into a polymer matrix by melt processing is a method that has been widely adopted in the recent past since it has the advantage of using equipment already commonly used to process thermoplastic materials (23)(24)(25)(26)(27)(28)(29)(30)(31)(32). This method also ensures large production volumes and solventless systems with obvious positive implications for environmental and economic factors.…”

“…Nevertheless, the high temperatures involved in melt processing may lead to the melting and/or decomposition of the antimicrobial agent, with consequent deactivation. Thus, it is mandatory to know both the melt and decomposition temperatures of the biocide additives in order to avoid their degradation.In our previous works, we successfully prepared different antimicrobial polymeric systems by melt compounding (24)(25)(26)(27)(29)(30)(31)(32). In particular, we incorporated different antibacterial additives into an appropriate polymeric matrix, taking both the final application and the processing temperature of the polymeric sample into account when choosing the polymer-antibacterial pairing.…”