Fabrication of Kidney Proximal Tubule Grafts Using Biofunctionalized Electrospun Polymer Scaffolds

• Published in: Macromolecular bioscience 2019-02, Vol.19 (2), p.e1800412-n/a
• Main Authors: Jansen, Katja, Castilho, Miguel, Aarts, Sanne, Kaminski, Michael M., Lienkamp, Soeren S., Pichler, Roman, Malda, Jos, Vermonden, Tina, Jansen, Jitske, Masereeuw, Rosalinde
• Format: Article
• Language: English
• Subjects: Biocompatible Materials - therapeutic use; Caproates - chemistry; Cell Proliferation; Cells, Cultured; Chloroform; Collagen (type IV); Dialysis; Dihydroxyphenylalanine; Dimethylformamide; Epithelial Cells - cytology; Fabrication; Grafts; Humans; Implantation; Kidney Failure, Chronic - surgery; Kidney transplantation; Kidney Tubules, Proximal - cytology; Kidney Tubules, Proximal - surgery; Kidneys; Lactones - chemistry; Mechanical properties; Microfibers; Monolayers; Nanofibers; Organs; polycaprolactone; Polymers; Proteins; regenerative medicine; renal replacement therapy; renal transport; Scaffolds; Secretion; Sodium; Solutes; tissue engineering; Tissue Engineering - methods; Tissue Scaffolds; Transplants - growth & development
• ISSN: 1616-5187; 1616-5195
• DOI: 10.1002/mabi.201800412

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. A new concept to create stand‐alone tubular constructs is described for renal replacement therapies: biofunctionalized electrospun polymer scaffolds enable luminal epithelialization with proximal tubule epithelial cells to construct kidney tubule grafts. The suitability of scaffold morphologies is examined with two cell lines of different cell sizes and origin by investigating tight junction formation, long‐term viability and transport functionality.