Preparation and Characterization of Functionalized Surgical Meshes for Early Detection of Bacterial Infections

Isotactic polypropylene (i-PP) nonabsorbable surgi-cal meshes are modified by incorporating a conducting polymer (CP) layer to detect the adhesion and growth of bacteria by sensing the oxidation of nicotinamide adenine dinucleotide (NADH), a metabolite produced by the respiration reactions of such micro-organisms, to NAD+. A three-step process is used for such incorporation: (1) treat pristine meshes with low-pressure O-2 plasma; (2) functionalize the surface with CP nanoparticles; and (3) coat with a homogeneous layer of electropolymerized CP using the nanoparticles introduced in (2) as polymerization nuclei. The modified meshes are stable and easy to handle and also show good electrochemical response. The detection by cyclic voltammetry of NADH within the interval of concentrations reported for bacterial cultures is demonstrated for the two modified meshes. Furthermore, Staphylococcus aureus and both biofilm-positive (B+) and biofilm-negative (B-) Escherichia coli cultures are used to prove real-time monitoring of NADH coming from aerobic respiration reactions. The proposed strategy, which offers a simple and innovative process for incorporating a sensor for the electrochemical detection of bacteria metabolism to currently existing surgical meshes, holds considerable promise for the future development of a new generation of smart biomedical devices to fight against post-operative bacterial infections.

Automated summary

Isotactic polypropylene nonabsorbable surgical meshes are modified by incorporating a conducting polymer layer that can detect the presence and growth of bacteria by sensing the oxidation of NADH. This process involves treating the meshes with low-pressure plasma, functionalizing the surface with CP nanoparticles, and coating a layer of electropolymerized CP. The modified meshes show stable and easy handling properties, as well as good electrochemical response, allowing for the detection of NADH and monitoring of bacterial metabolism.