Biocompatibility studies on polyaniline and polyaniline-silver nanoparticle coated polyurethane composite

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Medical-grade polyurethane (PU) is widely used but can elicit adverse biological responses.
• Surface modification is crucial for enhancing the biocompatibility and functionality of medical implants.
• Polyaniline (PANi) and its composites offer tunable electronic and biological properties.

Purpose of the Study:

• To evaluate the biocompatibility of medical-grade polyurethane coated with polyaniline (PANi) and polyaniline-silver nanoparticle composite (PANi-AgNp).
• To assess the impact of these coatings on cell viability, inflammatory response, and bacterial adhesion.
• To explore the potential applications of these modified surfaces in electrochemical biosensors.

Main Methods:

• Fabrication of PANi and PANi-AgNp coated polyurethane films.
• In vitro assessment of 3T3 L1 cell death and inflammatory cytokine gene expression (TNF-α, IL-6).
• Bacterial attachment studies using Pseudomonas and Bacillus, quantifying colony-forming units (CFU), protein, and carbohydrate adsorption.
• Biofilm thickness measurement and contact angle analysis.

Main Results:

• Modified PU films exhibited significantly lower 3T3 L1 cell death (23% for PANi, 18% for PANi-AgNp) compared to virgin PU (41%).
• Reduced expression of pro-inflammatory cytokines (TNF-α, IL-6) by 20% on modified surfaces.
• Markedly reduced bacterial attachment (Pseudomonas by 90.6%, Bacillus by 50.5%) on PANi-AgNp coated surfaces.
• A 20% reduction in biofilm thickness was observed on PANi-AgNp coated PU.
• Strong positive correlation between increased hydrophilicity (contact angle) and reduced bacterial adhesion, cell death, and inflammation.

Conclusions:

• Polyaniline and polyaniline-silver nanoparticle coatings enhance the biocompatibility of medical-grade polyurethane.
• These modified surfaces demonstrate reduced cytotoxicity, inflammation, and bacterial adhesion, making them suitable for biomedical applications.
• The conductive nature of the coatings suggests potential use in electrochemical biosensors.