Table 1.
Prepared anti-microbial sutures and normalized weights of chlorhexidine.
Table 2.
Mean tensile strength values of surgical sutures (USP 1).
Figure 1.
Elution profiles of chlorhexidine coated sutures.
Released chlorhexidine in PBS buffer at 37°C for A) chlorhexidine-laurate coatings and B) chlorhexidine-palmitate coated sutures. Elution profiles were determined for each carrier at drug content 11, 22 or 33 µg/cm. The horizontal lines depict the limit of drug release for each concentration, the normalized content of chlorhexidine on coated sutures.
Figure 2.
Percentage of chlorhexidine released after 96
Percentage of chlorhexidine release related to the drug content on coated sutures per cm length at 96) chlorhexidine-laurate and B) chlorhexidine-palmitate coated sutures.
Figure 3.
Measuring anti-bacterial efficacy of coated sutures via zones of inhibition.
A) Principle of measuring inhibition zones in a longitudinal analysis on the example of a Vicryl Plus suture, in order to achieve anti-microbial effectiveness over several days. B) Anti-microbial efficacies on Agar plates with S. aureus lawns (2×108 cfu/ml) for a) chlorhexidine lauric acid and b) chlorhexidine palmitic acid coated sutures. Coated suture samples with three different chlorhexidine concentrations 11, 22 and 33 µg/cm. c) Vicryl Plus as reference for commercial anti-microbial sutures.
Figure 4.
Evaluation of biocompatibility of coated sutures in cytotoxicity tests via WST-1 assay.
Metabolic cell activity of fibroblasts in the presence of eluates from coated sutures measured with the WST-1 proliferation assay. Cells were incubated with eluates from coated sutures, suture references: lauric acid (LA), palmitic acid (PA), uncoated suture (Gunze), and Vicryl Plus. All values referred to cellular growth control, pure L-929 mouse fibroblast cultures. Dashed line at 70% pictures the level for acceptable lowering of metabolic activity according to ISO 10993-5:2009 in order to declare biocompatibility of medical devices.