Antibacterial nanopatterned coatings for dental implants

Abstract

Dental implants, usually made of titanium, are exposed to hostile oral microflora that facilitates bacterial infections and subsequent inflammation. To mitigate these processes, we coated titanium substrates with block copolymer nanopatterns and investigated the bactericidal effect of these coatings against gram-positive and gram-negative bacteria. We found that the bactericidal efficacy of the coatings depends on their morphology and surface chemistry as well as on the bacterial strain: an optimal combination can lead to significant bacterial death for a short time, i.e. 90 % for 90 min. Human gingival fibroblasts in contact with the nanopatterned coatings showed similar cell attachment and morphology as on bare Ti. Immunostaining assays showed similar levels of CCR7 and CD206 in macrophages cultured over the nanopatterns and bare Ti, demonstrating adequate properties for tissue integration. The nanopatterns induced a small increase in macrophage aspect ratio, which might indicate early states of M2 polarization, given the absence of CD206.