Preparation and investigation of hydrolyzed polyacrylonitrile as a preliminary biomedical hydrogel

Trackability of a high-strength thromboresistant hydrogel catheter: An In vitro analysis comparing venous catheter forces in a simulated use pathway

As the need for vascular access devices (VADs) continues to increase, so does the need for innovative designs and materials that can improve placement and optimize patient outcomes. Commercially available peripherally inserted central venous catheters (PICCs) are in high demand due to their ease of use and low cost. However, they are constructed of materials that can contribute to vascular injury and result in complications such as clotting, catheter failure, and infection. This study investigated the surface and frictional properties of a HydroPICC® device constructed of a novel, inherently lubricious bulk hydrogel. Investigators posited that these materials would lower the forces required to advance and retract the HydroPICC® devices and that the measured forces are significantly lower than those of two commercially available PICCs made of conventional thermoplastic polyurethane. The HydroPICC® device had a lower insertion and retraction force compared to both the PowerPICC^TM and BioFlo^TM control devices based on an unpaired, two-sided t-test (P < .001). The HydroPICC® also exhibited a statistically significant decrease in average force when compared to both conventional PICCs (P < .001 and P = .001). When compared to PowerPICC^TM, the lubricious high-strength HydroPICC® hydrogel device exhibited an 84% ± 25% reduction in average tracking force; additionally, when compared to a fluoro-oligomer modified TPU catheter (BioFlo^TM), the HydroPICC® device exhibited a 90 ± 32% reduction in average tracking force. The HydroPICC® technology represents a new method to reduce frictional forces of implantable devices. Clinical trials are needed to determine whether the differences in frictional properties between conventional VADs and HydroPICC® devices translate into improved clinical outcomes.

Preparation of mango peel-waste pectin-based nanofibers by solution blow spinning (SBS)

An essential prerequisite for successful solution blow spinning (SBS) is the presence of effective molecular entanglements of polymers in the solution. However, the fabrication of biopolymer fibers is not as straightforward as synthetic polymers. Particularly for biopolymers such as pectin, molecular entanglements are essential but insufficient for successful spinning through the SBS production method. Such a challenge is due to the biopolymer's complex nature. However, incorporating an easily spinnable polymer precursor, such as polyacrylonitrile (PAN), to pectin effectively enabled the production of fibers from the SBS process. In this process, PAN-assisted pectin nanofibers are produced with average diameters ranging from 410.75 ± 3.73 to 477.09 ± 6.60 nm using a feed flow rate of 5 ml h^-1, air pressure of 3 bars, syringe tip to collector distance at 30 cm, and spinning time of 10 min. PAN in DMSO solvent at different volume ratios (i.e. 35%-55% v/v) was critical in assisting pectin to produce nanofibers. The addition of a high molecular weight polymer, PAN, to pectin also improved the viscoelasticity of the solution, eventually contributing to its successful SBS process. Furthermore, the composite SBS-spun fibers obtained suggest that its formation is concentration-dependent.

Novel high-strength thromboresistant poly(vinyl alcohol)-based hydrogel for vascular access applications

Adherence of proteins, cells, and microorganisms to the surface of biomaterials used for vascular access contribute to device failure by thrombosis, occlusions, and infections. Current technologies for inhibiting these complications are limited to coatings and additives that are limited in duration of efficacy and often induce adverse side effects. In this work, we developed a novel composite hydrogel structure comprising of a porous poly(vinyl alcohol) (PVA) that is impregnated with poly(acrylic acid) (PAA) and heat treated to create a physically cross-linked high-strength hydrogel material. The swelling and mechanical properties can be controlled by the temperature and duration of heat treatment to increase the cross-link density of the matrix. The heat treated composite PVA/PAA hydrogel exhibits both the mechanical strength and durability of thermoplastic polyurethanes (TPUs) and the inherently non-thrombogenic surface functionality of PVA-based hydrogels without the use of chemical cross-linking agents. The composite hydrogels were found to maintain their mechanical integrity and surface functionality after accelerated aging in a simulated-use in vitro model for 162.5 days real-time equivalent. Relative to commercial catheter materials, the composite PVA/PAA hydrogel exhibited up to an average of 97% reduction in platelet adhesion when exposed to an in vitro blood loop model and a lower rate of tip occlusion due to thrombosis. This high-strength thromboresistant hydrogel could have a major impact as a novel biomaterial for use in vascular access applications to improve patient health.