Friction behaviour of hydrophilic lubricious coatings for medical device applications

Abstract

The friction behaviour of new chitosan derivative coatings obtained by chemical modification of chitosan with fatty acids (linoleic and dilinoleic acid) has been investigated in order to explore their potential as endovascular catheter coatings and to benchmark them against commercially available coatings used in endovascular catheter applications. An in vitro tribological system was developed that was intended to represent to a limited extent the in vivo tribological conditions of a typical endovascular catheterization procedure. Continuous reciprocating sliding tests were carried out with uncoated and coated polymer specimens. The results showed that all of the coatings tested decreased the coefficient of friction compared to the uncoated polymer. Compared to a neat chitosan coating, the chitosan derivative coatings showed a clear reduction in the coefficient of friction to levels similar to those of the commercially-available coatings. A comparison between the friction results and contact angle measurements carried out on the coatings indicated that a range of contact angle values exists for which the friction coefficient is at a minimum. The reason for this is unclear and further studies are required in order to confirm and investigate the trend, especially within the context of hydrophilic lubricious coating development.

Measurement of Friction-induced Changes in Pig Aorta Fibre Organization by Non-invasive Imaging as a Model for Detecting the Tissue Response to Endovascular Catheters

“…The techniques of SHG and TPEF have been previously used to investigate collagen and elastin networks, respectively, in arteries [10,20] heart valves [12,21] porcine cartilage [22] and skin [23].…”

“…To mimic the in vivo state of the unpressurised aorta, a tissue sample holder was developed by Philips Research, Eindhoven, Netherlands and the West Pomeranian University of Technology, Szczecin, Poland to hold the aorta sample during the friction test and maintain uniaxial tension. This device has been described elsewhere [12]. The fresh pig aorta was flattened in the longitudinal direction, the sample length increased by 15 %, reflecting the degree of stretching observed during normal blood flow, and the sample held in place.…”

The influence of the nylon balloon stiffness on the efficiency of the intra‐aortic balloon occlusion

“…The technique significantly lowers the friction ratio. For instance, as may be found in the paper of Niemczyk et al, for nylon‐33 and nylon‐69, the friction ratios were deceased from 0.28 to 0.06 and from 0.180 to 0.015, respectively. The reduced values were obtained when the nylon materials with the commercially used hydrophilic coatings were tested.…”

Evaluation of catheter-induced tribological damage to porcine aorta using infra-red spectroscopy

“…It is important to note here that there are several possible approaches that could be used to damage the aortic wall. The two most relevant to catheterization are incisions and friction (i.e., abrasion) [47]. In this study emphasis is placed on abrasion as it produces more even (i.e., uniform) mechanical damage of the arterial wall structure.…”