Mitigation of Cellular and Bacterial Adhesion on Laser Modified Poly (2-Methacryloyloxyethyl Phosphorylcholine)/Polydimethylsiloxane Surface

Abstract

Nowadays, using polymers with specific characteristics to coat the surface of a device to prevent undesired biological responses can represent an optimal strategy for developing new and more efficient implants for biomedical applications. Among them, zwitterionic phosphorylcholine-based polymers are of interest due to their properties to resist cell and bacterial adhesion. In this work, the Matrix-Assisted Laser Evaporation (MAPLE) technique was investigated as a new approach for functionalising Polydimethylsiloxane (PDMS) surfaces with zwitterionic poly(2-Methacryloyloxyethyl-Phosphorylcholine) (pMPC) polymer. Evaluation of the physical–chemical properties of the new coatings revealed that the technique proposed has the advantage of achieving uniform and homogeneous stable moderate hydrophilic pMPC thin layers onto hydrophobic PDMS without any pre-treatment, therefore avoiding the major disadvantage of hydrophobicity recovery. The capacity of modified PDMS surfaces to reduce bacterial adhesion and biofilm formation was tested for Gram-positive bacteria, Staphylococcus aureus (S. aureus), and Gram-negative bacteria, Escherichia coli (E. coli). Cell adhesion, proliferation and morphology of human THP-1 differentiated macrophages and human normal CCD-1070Sk fibroblasts on the different surfaces were also assessed. Biological in vitro investigation revealed a significantly reduced adherence on PDMS–pMPC of both E. coli (from 29 × 10 6 to 3 × 102 CFU/mL) and S. aureus (from 29 × 106 to 3 × 102 CFU/mL) bacterial strains. Additionally, coated surfaces induced a significant inhibition of biofilm formation, an effect observed mainly for E. coli. Moreover, the pMPC coatings improved the capacity of PDMS to reduce the adhesion and proliferation of human macrophages by 50% and of human fibroblast by 40% compared to unmodified scaffold, circumventing undesired cell responses such as inflammation and fibrosis. All these highlighted the potential for the new PDMS–pMPC interfaces obtained by MAPLE to be used in the biomedical field to design new PDMS-based implants exhibiting long-term hydrophilic profile stability and better mitigating foreign body response and microbial infection.

Silver/Graphene Oxide Nanostructured Coatings for Modulating the Microbial Susceptibility of Fixation Devices Used in Knee Surgery

“…Highly biocompatible nanostructured coatings with application-related biofunctional outcomes (immunomodulation, antimicrobial efficiency, antitumor activity) have been developed through the MAPLE technique [ 82 , 83 ], which represents an attractive and tunable strategy for the unaltered, stoichiometric, and stable transfer of small-molecule or macromolecule organics. With the aim to achieve the unaltered and efficient transfer of MAPLE-processed coatings, the optimal selection of laser parameters (mainly, the laser energy distribution over the effective target area) is generally required.…”

Surface pre-treatment of aluminum alloy for mechanical improvement of adhesive bonding by maple-assisted pulsed laser evaporation technique

“…To irradiate the target (practically, the frozen aqueous solutions) a Continuum Company's Surelite II pulsed Nd:YAG laser system was used, operating at a wavelength of 266 nm, with a pulse of 6 ns and a repetition rate of 10 Hz. Based on previous works on MAPLE deposition of polymers or other sensitive compounds, 25,26 as well as on the necessity to have full coverage of the 1 cm 2 areas from the Al plate, the number of pulses used was 72.000, while the chosen uence that could ensure no chemical modication was 350 mJ cm −2 . The target holder was continuously rotated (20 rpm) throughout the irradiation process to prevent the target from overheating.…”

Covalent bonding of quaternary ammonium compounds and zwitterionic polymer functional layers on polydimethylsiloxane against Escherichia Coli adhesion

“…For example, zwitterionic phosphorylcholine-based polymers grafted onto PDMS surfaces using the matrix-assisted laser evaporation technique significantly reduce E. coli and S. aureus adhesion. 14 [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) grafted onto PDMS surfaces using oxygen plasma treatment could reduce salt deposition for urinary applications. 15 To enhance the ability of materials against biofouling, surface modification using both bactericidal polymer brushes and nonfouling zwitterionic polymer brushes has been studied.…”