Wahl, P. | Search bioRxiv

bioRxiv2024

Enabling Hydrogel Coating on Silicone Breast Implants with Poly(Vinyl Acetate) Primer Layer

Implant-associated infection is a major cause for breast implant re-operation. A practical method to reduce this risk is yet to be established. Hydrogel coating represents one promising approach. However, the adhesion of the hydrogel layer onto the silicone implant surface presents a significant challenge due to the intrinsic hydrophobicity of silicone surfaces. In this study, we described a surface-priming strategy involving poly(vinyl acetate) (PVAc) polymers to facilitate hydrogel adhesion to silicone implant surfaces. Miniature silicone implants with identical surface properties to clinical implants were custom-made for this study. We demonstrated that a PVAc primer layer can easily be deposited on the implant surface via a dip-coating procedure. The wettability of the implant surface was increased by this primer layer, as confirmed by contact angle measurements. The improved wettability allowed the application of a model hydrogel precursor solution (alginate) on the primed implant surface. The effectiveness of such a priming strategy in facilitating hydrogel coating was validated by testing two commercially available hydrogels on the silicone implant surface. Specifically, DAC (Defensive Antibacterial Coating) and Coseal hydrogels, representing paintable and sprayable hydrogels respectively, were successfully coated on the primed surface, as confirmed by ATR-FTIR analysis. Our surface priming strategy, which avoids surface treatments like chemical reactions and plasma irradiation that are impractical for clinical use, opens up new opportunities for exploring intraoperative hydrogel applications on silicone implants.

bioengineering↗

bioRxiv2023

The role of ion dissolution in metal and metal oxide surface inactivation of SARS-CoV-2

Antiviral surface coatings are under development to prevent viral fomite transmission from high-traffic touch surfaces in public spaces. Coppers antiviral properties have been widely documented; but the antiviral mechanism of copper surfaces is not fully understood. We screened a series of metal and metal oxide surfaces for antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19). Copper and copper oxide surfaces exhibited superior anti-SARS-CoV-2 activity; however, level of antiviral activity was dependent upon the composition of the carrier solution used to deliver virus inoculum. We demonstrate that copper ions released into solution from test surfaces can mediate virus inactivation, indicating a copper ion dissolution-dependent antiviral mechanism. Level of antiviral activity is, however, not dependent on the amount of copper ions released into solution per se. Instead, our findings suggest that degree of virus inactivation is dependent upon copper ion complexation with other biomolecules (e.g., proteins/metabolites) in the virus carrier solution that compete with viral components. Although using tissue culture-derived virus inoculum is experimentally convenient to evaluate the antiviral activity of copper-derived test surfaces, we propose that the high organic content of tissue culture medium reduces the availability of "uncomplexed" copper ions to interact with the virus, negatively affecting virus inactivation and hence surface antiviral performance. We propose that laboratory antiviral surface testing should include virus delivered in a physiologically relevant carrier solution (saliva or nasal secretions when testing respiratory viruses) to accurately predict real-life surface antiviral performance when deployed in public spaces. ImportanceThe purpose of evaluating antiviral activity of test surfaces in the laboratory is to identify surfaces that will perform efficiently in preventing fomite transmission when deployed on high-traffic touch surfaces in public spaces. The conventional method in laboratory testing is to use tissue culture-derived virus inoculum, however this study demonstrates that antiviral performance of test copper-containing surfaces is dependent on the composition of the carrier solution in which the virus inoculum is delivered to test surfaces. Therefore, we recommend that laboratory surface testing should include virus delivered in a physiologically relevant carrier solution, to accurately predict real-life test surface performance in public spaces. Understanding the mechanism of virus inactivation is key to future rational design of improved antiviral surfaces. Here, we demonstrate that copper ions released from copper surfaces into small liquid droplets containing SARS-CoV-2, is a mechanism by which the virus that causes COVID-19 can be inactivated.

microbiology↗