HPMC-ZnO Nanorods Enhance Hydrophilicity and Contact-Killing Activity on Polypropylene Meshes and Sutures

TL;DR

A new coating made of HPMC and ZnO nanorods improves the safety of surgical meshes and sutures by reducing bacterial adhesion and killing bacteria effectively.

Contribution

A novel HPMC-ZnO nanorod coating is developed to enhance the antibacterial and anti-adhesive properties of polypropylene medical devices.

Findings

The HPMC-ZnO coating reduced water contact angles by ~41°, significantly improving hydrophilicity.

The coating inhibited bacterial attachment by up to 99.6% for Klebsiella pneumoniae and showed long-term efficacy for six months.

In vivo tests showed negligible systemic toxicity of ZnO nanorods in murine models.

Abstract

Background: Biomedical device-associated infections pose major challenges in surgical care, particularly in hernia repair where polypropylene (PP) meshes and sutures are prone to bacterial colonization and biofilm formation. The limitations of antibiotic resistance and toxicity warrants the need of developing innovative antibacterial strategies. Methods: We developed a composite coating of hydroxypropyl methylcellulose (HPMC) and zinc oxide nanorods (ZnO NP) synthesized via thermal decomposition. This coating was applied to PP meshes and sutures to enhance anti-adhesive properties. The study evaluated surface hydrophilicity through water contact angles, estimation of Zn2+ ions using inductively coupled plasma–mass spectrometry (ICP-MS), and long-term efficacy over six months. Safety was assessed via systemic toxicity studies in murine models. Results: The ZnO NPs exhibited potent antibacterial efficacy, achieving up to 99.999% killing against Klebsiella pneumoniae. When applied as an HPMC-ZnO coating, PP meshes and sutures demonstrated enhanced hydrophilicity, reducing water contact angles by ~41° and facilitating prevention of bacterial adhesion. The coated meshes inhibited bacterial attachment by 83% (Escherichia coli), 60% (Pseudomonas aeruginosa), 99.6% (K. pneumoniae), and 99% (Staphylococcus aureus). Similarly, coated sutures reduced adhesion by 67–96% across these strains. Long-term storage studies showed retained antibiofilm efficacy for up to six months. In vivo assessments indicated negligible systemic toxicity of ZnO NPs in murine models. Conclusions: Collectively, these findings highlight HPMC-ZnO NPs coatings as a safe, durable, and effective strategy to functionalize PP-based meshes and sutures, reducing the risk of surgical site infections and demonstrating the potential for broader biomedical applications.

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