Abstract
Purpose: :
Biofilms are matrix-associated microbial communities adherent to either biological surfaces or abiotic (non-biological) surfaces, account for over 80% of device-associated infections, and are noteworthy for natural resistance to antimicrobial agents and the host immune defense mechanisms. Bio-prosthetic intraocular devices have a similar intrinsic risk of biofilm infections as other prosthetic materials. The Boston KeratoprosthesisTM (Boston KProTM) is able to return sight not achievable long-term by other surgical interventions, yet require life-long antibiotic prophylaxis to prevent infection. Our goal is to prevent or inhibit bacterial adherence and biofilm formation by the use of new polyethylenimines (PEI) bound to bio-prosthetic ocular-associated materials (poly methyl 2-methyl propenoate (PMMA)) using the Boston KProTM as a model system.
Methods: :
140 Staphylococcus aureus ocular-associated clinical isolates were evaluated by gentian violet staining for robust biofilm formation. By confocal laser scanning microscopy (CLSM) and electron microscopy, an assessment of S. aureus microbial biofilm formation by a linear version of N, N-dodecyl, methyl-polyethylenimine (LPEI) (217 kDa) covalently bound to PMMA (LPEI-PMMA) compared to PMMA alone has been performed. In addition, LPEI-PMMA materials were screened for corneal cell culture cytotoxicity compared to PMMA alone.
Results: :
By the use of biofilm-forming S. aureus ocular-associated clinical isolates and a hyperbiofilm laboratory mutant (MN8n), we have demonstrated a significant inhibitory effect in biofilm formation on the LPEI-PMMA materials compared to PMMA. We have also demonstrated a lack of corneal epithelial cell cytotoxicity of LPEI-PMMA compared to PMMA.
Keywords: bacterial disease • Staphylococcus • endophthalmitis