Biohybrid elastin-like venous valve with potential for in situ tissue engineering.

Chronic venous insufficiency (CVI) is a leading vascular disease whose clinical manifestations include varicose veins, edemas, venous ulcers, and venous hypertension, among others. Therapies targeting this medical issue are scarce, and so far, no single venous valve prosthesis is clinically available. Herein, we have designed a bi-leaflet transcatheter venous valve that consists of (i) elastin-like recombinamers, (ii) a textile mesh reinforcement, and (iii) a bioabsorbable magnesium stent structure. Mechanical characterization of the resulting biohybrid elastin-like venous valves (EVV) showed an anisotropic behavior equivalent to the native bovine saphenous vein valves and mechanical strength suitable for vascular implantation. The EVV also featured minimal hemolysis and platelet adhesion, besides actively supporting endothelialization in vitro, thus setting the basis for its application as an in situ tissue engineering implant. In addition, the hydrodynamic testing in a pulsatile bioreactor demonstrated excellent hemodynamic valve performance, with minimal regurgitation (<10%) and pressure drop (<5 mmHg). No stagnation points were detected and an in vitro simulated transcatheter delivery showed the ability of the venous valve to withstand the implantation procedure. These results present a promising concept of a biohybrid transcatheter venous valve as an off-the-shelf implant, with great potential to provide clinical solutions for CVI treatment.

Primary Design Concept for Non-metallic Needle for MRI Guided Spinal Applications.

This work describes an initial design concept for a spinal needle using new materials to optimize their visualization in magnetic resonance imaging. Common MRI needles made of Nickel-Titanium alloys still show poor visibility in imaging because they generate susceptibility artifacts due to material's interactions with the magnetic environment. The use of non-metallic materials can reduce these artifacts. However, so far no non-metallic needle design has made it to clinical routine due to sharpness and cost issues. We propose a design of a coaxial needle with a fiber enforced inner core and an outer hollow sheet. The concept has been evaluated in the MRI environment. Additionally, mechanical tests were performed to examine and quantify the variation between a conventional spinal needle and our proposed design.