LAUSR

Polymicrobial infections are one of the most common reasons for inflammation of surrounding tissues and failure of implanted biomaterials. Because microorganism adhesion is the first step for biofilm formation, physical-chemical modifications of biomaterials have been proposed to reduce initial microbial attachment. Thus, the use of superhydrophobic coatings has emerged because of its anti-biofilm properties. However, these coatings on titanium (Ti) surface have been developed mainly by dual-step syrface modification techniques and have not been tested using polymicrobial biofilms. Therefore, we developed a one-step superhydrophobic coating on Ti surface by using low pressure plasma technology to create a biocompatible coating that reduces polymicrobial biofilms adhesion and formation. The superhydrophobic coating on Ti was created by the glow discharge plasma using Ar, O2 and hexamethyldisiloxane (HMDSO) gases, and after full physical, chemical and biological characterizations, we evaluated its properties regarding oral biofilm inhibition. The newly developed coating presented an increased surface roughness and, consequently, superhydrophobicity (contact angle over 150); and enhanced corrosion resistance (p<0.05) of Ti surface. Futhermore, proteomic analysis showed a unique pattern of protein adsorption on the superhydrophobic coating without drastically changing the biologic processes mediated by proteins. Additionally, superhydrophobic treatment did not present cytotoxic effect on fibroblasts or reduction of proliferation; however, it significantly reduced (8-fold change) polymicrobial adhesion (bacterial and fungal) and biofilm formation in vitro. Interestingly, superhydrophobic coating shifted the microbiological profile of biofilms formed in situ in the oral cavity, reducing by up to 7 fold pathogens associated with peri-implant disease. Thus, this new superhydrophobic coating developed by one-step glow discharge plasma technique is a promising biocompatible strategy to drastically reduce microbial adhesion and biofilm formation on Ti-based biomedical implants.