Surface Modification Using Ultraviolet-Ozone Treatment Enhances Acute Drug Transfer in Drug-Coated Balloon Therapy.

Endovascular deployment of drug-coated balloons (DCB) is an emerging strategy for the revascularization of arterial disease. Randomized clinical trials have demonstrated DCB effectiveness, but a recent meta-analysis reported increased mortality risk in humans with use of DCBs containing the common antiproliferative drug paclitaxel. While many factors could have contributed to adverse outcomes, current DCB designs have poor drug delivery efficiency, risk of systemic toxicity, and limited potential to retain therapeutic drug concentrations within the arterial wall following the procedure. Our study focuses on developing a strategy to enhance acute drug transfer from the balloon to the arterial wall over the short procedural window (∼30-120 s). We employed ultraviolet-ozone plasma (UVO) treatment to increase the hydrophilicity of a prototypical balloon material (Nylon-12) and subsequently applied a urea-paclitaxel coating previously shown to undergo favorable adhesive interactions with the arterial wall under simulated ex-vivo deployment. A series of assays were performed to characterize our experimental DCBs in terms of UVO-induced alterations in balloon surface hydrophobicity, formed coating microstructure, coating stability, and acute drug transfer to the arterial wall. Obtained results suggest that the UVO-based surface modification of angioplasty balloons is a promising design strategy and highlights the critical role of coating microstructure in determining the drug transfer efficiency in DCB therapy.

Estimation of Size and Contact Angle of Evaporating Sessile Liquid Drops Using Texture Analysis.

Size and contact angle of liquid drops are fundamental parameters in interfacial science. Accurate estimation of these parameters can provide objective information regarding several properties of the contacting surface. We leveraged principles of texture analysis to estimate the contact angle and the drop diameter from videos of evaporating sessile liquid drops deposited on solid surfaces. Specifically, we used a Harris corner detector to locate the corners and dynamically estimate the changing size and a Gabor wavelet-based approach to estimate the varying contact angle of the evaporating sessile drop. We demonstrated the ability of our approach to accurately estimate size and contact angles of drops deposited on a hydrophilic glass slide and on a paraffin film representing a hydrophobic surface. We also estimated the contact angle and size of drops deposited on horizontal and tilted surfaces to generate symmetric and asymmetric drop shapes, respectively. A software application that has the ability to analyze videos of sessile liquid drops as inputs is provided, and this tool can generate plots of the estimated contact angle and the drop diameter as a function of frame number.