Bioresorbable microspheres by spinning disk atomization as injectable cell carrier: from preparation to in vitro evaluation

• Published in: Biomaterials Vol. 21; no. 11; pp. 1135 - 1144
• Main Authors: Senuma, Y, Franceschin, S, Hilborn, J.G, Tissières, P, Bisson, I, Frey, P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2000; Elsevier Science
• Subjects: Absorbable Implants; Animals; Atomization; Biocompatibility; Biocompatible Materials; Biological and medical sciences; Biopolymers; Bioresorbable polymer; Cell carrier; Cells, Cultured; Evaluation Studies as Topic; Living systems studies; Male; Medical sciences; Microscopy, Electron, Scanning; Microspheres; Muscle; Porous microspheres; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Rats; Rats, Wistar; Spinning disk atomization; Technology. Biomaterials. Equipments. Material. Instrumentation; Temperature control; Thermal effects; Tissue engineering; Urinary Bladder - cytology; Vesico-ureteral reflux; Cell carrier; Bioresorbable polymer; Vesico-ureteral reflux; Tissue engineering; Porous microspheres; Spinning disk atomization; Cell culture; Injectable form; Urinary system disease; Microsphere; Biodegradability; Control release polymer; Urinary tract disease; In vitro; Lactic acid polymer; Treatment; Manufacturing process; Vesicoureteral reflux; Bladder disease; Atomization; Biomedical engineering
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/S0142-9612(99)00276-8

Vesico-ureteral reflux, a common pathology in children, can be treated cystoscopically by injection of a bulking material underneath the most distal, intramural ureter, which forces the latter to do a detour, increasing its submucosal path. This increase of the length of the submucosal path of the ureter within the bladder is directly responsible for the anti-reflux effect. So far Teflon and collagen paste have been commonly used as bulking materials. We suggest replacing these materials by living tissue consisting of bladder smooth muscle, normally present at this location. The aim of this work is to provide a long-term effective treatment by producing bioresorbable microspheres which can act as a support matrix and an entrapment substance for bladder smooth muscle cells, with the goal of an in vivo transfer of the in vitro cultured cells with a minimal surgical procedure. By the use of Spinning Disk Atomization, which has specifically been developed for this purpose, we have shown two methods for the preparation of porous poly(lactic acid) microspheres with tunable sizes from 160 to 320
μm. The controlled solvent burst method has shown the advantage over the crystal leaching method in the direct creation of microspheres with large closed pores, by atomizing the polymer solution in controlled temperature conditions. Microspheres with various closed pore structures have thus been prepared. The innovation of this work is in the direct and rapid formation of porous microspheres with a pore morphology which is designed to create cavities suitable for adherence and growth of cells by adapting the temperature conditions of atomization. Injection tests have shown promising results in using these cell-loaded microspheres for future non-invasive tissue engineering.