Plasma-deposited membranes for controlled release of antibiotic to prevent bacterial adhesion and biofilm formation

Abstract

Bacterial infection on implanted medical devices is a significant clinical problem caused by the adhesion of bacteria to the biomaterial surface followed by biofilm formation and recruitment of other cells lines such as blood platelets, leading to potential thrombosis and thromboembolisms. To minimize biofilm formation and potential device-based infections, a polyurethane (Biospan) matrix was developed to release, in a controlled manner, an antibiotic (ciprofloxacin) locally at the implant interface. One material set consisted of the polyetherurethane (PEU) base matrix radiofrequency glow discharge plasma deposited with triethylene glycol dimethyl ether (triglyme); the other set had an additional coating of poly(butyl methyacrylate) (pBMA). Triglyme served as a nonfouling coating, whereas the pBMA served as a controlled porosity release membrane. The pBMA-coated PEU contained and released ciprofloxacin in a controlled manner. The efficacy of the modified PEU polymers against Pseudomonas aeruginosa suspensions was evaluated under flow conditions in a parallel plate flow cell. Bacterial adhesion and colonization, if any, to the test polymers were examined by direct microscopic image analysis and corroborated with destructive sampling, followed by direct cell counting. The rate of initial bacterial cell adhesion to triglyme-coated PEU was 0. 77%, and to the pBMA-coated PEU releasing ciprofloxacin was 6% of the observed adhesion rates for the control PEU. However, the rate of adherent cell accumulation due to cell growth and replication was approximately the same for the triglyme-coated PEU and the PEU controls, but was zero for the pBMA-coated PEU releasing ciprofloxacin.

Surface Treatments to Modulate Bioadhesion: A Critical Review

“…From research such as this, it is possible to foresee that plasma-based technologies could potentially be used for polymeric biomaterials in order to improve upon their bioactivity for use in biological environments. Plasma surface treatments have also been extensively used in the production of surfaces to control and investigate bacterial adhesion on numerous material types [148][149][150][151][152][153][154][155]. Plasma immersion ion implantation has been applied to surface treat poly(vinyl chloride) (PVC) [153] to successfully improve the antibacterial properties with specific regard to Staphylococcus aureus and E. coli.…”

Small-molecule-hosting nanocomposite films with multiple bacteria-triggered responses

“…To circumvent electrostatic repulsion between film components, assembly was performed at pH 2.2, at which PAA carries no negative charge (pK a of PAA is B6.8). AFM measurements of film thickness by scanning the AFM tip over a razor scratch in the film confirmed that, similar to other clay-polyelectrolyte multilayers, 15,19 the dry thickness increased linearly with the number of deposited layers (Figure 1a), suggesting a low diffusivity of film components during deposition. The bilayer thickness for the MMT/PAA system of B15 nm is not unusual for polyelectrolyte/MMT, for which larger bilayer thicknesses have been reported, 32 with differential thicknesses of 11 ± 1 nm for clay and 4 ± 1 nm for PAA.…”

“…To alleviate this problem, a number of approaches 15 have been proposed to modify surfaces with polymer coatings that are anti-adhesive, 16,17 kill bacteria on contact, 18 elute antimicrobial compounds with time 19 or provide antibacterial protection through enzymatic degradation of a biofilm matrix. 20 The assembly of surface coatings via LbL deposition enables the inclusion of a broad range of components within conformal coatings and has been explored to construct contact-killing 21 or release-killing films.…”

Application of Low-Temperature Plasma Processes for Biomaterials

“…Changing the deposition time length resulted in different coating thickness which, like the molecular weight of the drug, was found to influence the drug-release rate. A comparable approach was used on polyetherurethane onto which a plasma-deposited poly(butyl methyacrylate) membrane with controlled porosity was applied to control the release of ciprofloxacin (Hendricks et al, 2000). Adhesion and colonization of Pseudomonas aeruginosa was evaluated to assess the antimicriobial effectiveness.…”