Antibacterial Properties of Plasma Functionalized Surfaces Immobilization with Aggregation-Induced Emission Photosensitizers for Preventing Surgical Site Infection

Author: Resmarani Sahu

  • Thesis download: available for open access on 11 Jan 2025.

Sahu, Resmarani, 2023 Antibacterial Properties of Plasma Functionalized Surfaces Immobilization with Aggregation-Induced Emission Photosensitizers for Preventing Surgical Site Infection, Flinders University, College of Medicine and Public Health

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Bacterial illnesses are major threats to human health because of the number of antibiotic-resistant bacteria causing significant mortality and morbidity in the general population. Surgical site infection (SSI) is one of the major bacterial infections that appears at the site of surgery with the entry of microorganisms. Aggregation-induced emission luminogens (AIEgens), with their distinct optical characteristics, biocompatibility, low toxicity, and target specificity, hold the potential for the treatment of SSIs as an antibacterial therapy with restricted reactive oxygen species (ROS) in their aggregation state. Herein, an AIEgen-immobilized plasma-polymerized substrate is reported to develop AIE active photosensitisers (PSs) with ROS generation ability for the successful prevention of drug-resistant bacteria at the surgical site. The plasma-polymerized surfaces are substrate-independent and it improves the binding of AIEgens to the substrate without changing the properties of either the substrate or AIEgens. However, since the cyano group and cationic charge have such strong surface binding affinities, the cationic CN-TPAQ-PF6 exhibits outstanding photodynamic killing efficiency. It eradicates >90% of S. aureus and >99.99% of P. aeruginosa bacteria, respectively, at a very low concentration of 10 -14 µg/ml under low-intensity light exposure (40 mW cm-2) for 1 hour. Further, CN-TPAQ-PF6 have enhanced ROS generation capacity in compare to TPAQ-PF6 This CN-TPAQ-PF6 immobilised plasma coated surface showed a high cell viability rate towards HacaT cell in compared to the TPAQ-PF6 immobilised plasma coated surface. Furthermore, the cationic CN-TPAQ-PF6 is immobilized on a medical device suture for effective application in the biomedical field to prevent antibiotic-resistant bacterial infections. With more in-depth in-vivo research, our work illuminates potential future directions for innovative medicinal uses of AIEgens to combat antibiotic resistance.

Keywords: aggregation-induced emission (AIE), anti-bacterial, Gram-positive, gram-negative, photosensitisers (PSs), fluorescence, Toxicity, surgical site infection.

Subject: Biotechnology thesis

Thesis type: Masters
Completed: 2023
School: College of Medicine and Public Health
Supervisor: Prof. Youhong Tang