Antimicrobial PDMS Surfaces Prepared through Fast and Oxygen-Tolerant SI-SARA-ATRP, Using Na₂SO₃ as a Reducing Agent

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Science

Background:

• Poly(dimethylsiloxane) (PDMS) is widely used in biomedical devices due to its favorable properties.
• The inherent hydrophobicity of PDMS leads to microbial colonization, necessitating antimicrobial surfaces.
• Existing surface modification methods for PDMS are limited in scope and scalability.

Purpose of the Study:

• To develop a simple, scalable method for creating antimicrobial PDMS surfaces.
• To functionalize PDMS surfaces with poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) brushes.
• To investigate the antimicrobial properties of the modified surfaces based on charge density and amphiphilicity.

Main Methods:

• Grafting of a novel atom transfer radical polymerization (ATRP) initiator onto the PDMS surface.
• Surface-initiated supplemental activator and reducing agent ATRP (SI-SARA-ATRP) using sodium sulfite.
• Quaternization of the grafted PDMAEMA brushes with alkyl halides.

Main Results:

• Successful grafting of PDMAEMA brushes onto PDMS surfaces with fast and linear polymer growth (400 nm in 120 min).
• The SI-SARA-ATRP method demonstrated high oxygen tolerance and robustness.
• Antimicrobial activity was significantly influenced by the charge density and amphiphilicity of the quaternized surfaces.

Conclusions:

• The developed method provides a facile and scalable route to antimicrobial PDMS surfaces.
• The functionalized PDMS surfaces exhibit tunable antimicrobial properties.
• This advancement facilitates the broader application of PDMS in infection-prone biomedical devices.