Laser-assisted process for the deposition of nanostructured anti-microbial coatings on hydrogels

Antimicrobial coatings can inhibit the growth of microbes on hydrogel which have been used in various biomedical devices, such as contact lenses, implantable stents, and tissue substitutes. However, the expensive cleanroom is required to deposit antimicrobial coatings on hydrogel used for biomedical devices. Herein, a new laser process, matrix-assisted pulsed laser evaporation (MAPLE), has been developed to deposit nanostructured anti-microbial coatings on silicone hydrogel without the additional sterilizing process or pretreatments. Nd: YAG laser with a wavelength (lambda) of 532 nm was applied in the MAPLE system. Two different laser-assisted processes have been employed to deposit polyvinylpyrrolidone modified silver nanoparticles (PVP-Ag NPs) on silicone hydrogel (1) Process-A: PVP-Ag NPs prepared by photochemical reduction following the deposition of PVP-Ag NPs on silicone hydrogel by MAPLE; (2) Process-B. MAPLE system has been employed to directly produce and deposit PVP-Ag NPs on the surface of silicone hydrogel. The protein adsorption is 14.109 mu g/cm2 and 13.729 mu g/ cm2 to silicone hydrogels coated with PVP-Ag NPs made by Process-A and Process-B, respectively. It is observed that the protein adsorption is 16.10 +/- 0.75 mu g/cm2 to silicone hydrogels without PVP-Ag NPs coatings. In addition, Escherichia coli (E. coli) cells were cultured on silicone hydrogel with/without PVP-Ag NPs coatings. The result indicates that the growth of E. coli can be significantly inhibited when silicone hydrogel is coated with PVP-Ag NPs. The relative viability of E. coli on silicone hydrogel coated with PVP-Ag NPs decreases over 55% (made by Process-A) and 75% (made by Process-B), respectively, when culture time increases from 1 to 6 h. This study introduces a new laser-assisted process to coat antimicrobial coatings on silicone hydrogel without the cleanroom environment.

Automated summary

A new laser process called matrix-assisted pulsed laser evaporation (MAPLE) has been developed to deposit nanostructured antimicrobial coatings on silicone hydrogel without the need for additional sterilization or pretreatment. The study shows that these coatings can significantly inhibit the growth of bacteria on silicone hydrogel.