Fabrication of Kidney Proximal Tubule Grafts Using Biofunctionalized Electrospun Polymer Scaffolds.

The increasing prevalence of end-stage renal disease and persistent shortage of donor organs call for alternative therapies for kidney patients. Dialysis remains an inferior treatment as clearance of large and protein-bound waste products depends on active tubular secretion. Biofabricated tissues could make a valuable contribution, but kidneys are highly intricate and multifunctional organs. Depending on the therapeutic objective, suitable cell sources and scaffolds must be selected. This study provides a proof-of-concept for stand-alone kidney tubule grafts with suitable mechanical properties for future implantation purposes. Porous tubular nanofiber scaffolds are fabricated by electrospinning 12%, 16%, and 20% poly-ε-caprolactone (PCL) v/w (chloroform and dimethylformamide, 1:3) around 0.7 mm needle templates. The resulting scaffolds consist of 92%, 69%, and 54% nanofibers compared to microfibers, respectively. After biofunctionalization with L-3,4-dihydroxyphenylalanine and collagen IV, 10 × 106 proximal tubule cells per mL are injected and cultured until experimental readout. A human-derived cell model can bridge all fiber-to-fiber distances to form a monolayer, whereas small-sized murine cells form monolayers on dense nanofiber meshes only. Fabricated constructs remain viable for at least 3 weeks and maintain functionality as shown by inhibitor-sensitive transport activity, which suggests clearance capacity for both negatively and positively charged solutes.

The Minimally Invasive Manipulator: an ergonomic and economic non-robotic alternative for endoscopy?

INTRODUCTION: Since the da Vinci robotic system was introduced, it has been reported to have ergonomic advantages over conventional laparoscopy (COV). High investments associated with this system challenged us to design a more economical, mechanical alternative for improvement of laparoscopic ergonomics: the Minimally Invasive Manipulator (MIM). MATERIAL AND METHODS: An earlier reported MIM prototype was investigated. Its shortcomings were input for the establishment of design criteria for a new prototype. RESULTS: A new prototype was developed, aiming at improved intuitiveness and ergonomics. The handle and instrument tip were redesigned and the parallelogram mechanism was converted from linear moving parts to mainly rotating parts. DISCUSSION: The new prototype was tested by a panel of experts and novices during an indicative ergonomic experiment. A major advantage of the MIM seems to be the possibility to perform laparoscopic surgery in a sitting position, in line with the working axis, instead of standing at the side of the patient. At an estimated cost level of 10% of the da Vinci system, the MIM can be an economical alternative for the enhancement of laparoscopy ergonomics. However, further development for clinical feasibility is necessary.