Tissue engineering in urology

Abstract

Tissue engineering encompasses a multidisciplinary approach geared toward the development of biological substitutes designed to restore and maintain normal function in diseased or injured tissues. This article reviews the basic technology that is used to generate implantable tissue-engineered grafts in vitro that will exhibit characteristics in vivo consistent with the physiology and function of the equivalent healthy tissue. We also examine the current trends in tissue engineering designed to tailor scaffold construction, promote angiogenesis and identify an optimal seeded cell source. Finally, we describe several currently applied therapeutic modalities that use a tissue-engineered construct. While notable progress has clearly been demonstrated in this emerging field, these efforts have not yet translated into widespread clinical applicability. With continued development and innovation, there is optimism that the tremendous potential of this field will be realized.Can Urol Assoc J 2009;3(5):403-8 Résumé L'ingénierie tissulaire englobe une approche multidisciplinaire axée sur le développement de substituts biologiques en vue de rétablir et de maintenir la fonction normale de tissus lésés. L'article qui suit passe en revue la technologie fondamentale utilisée pour générer des greffons implantables produits par ingénierie in vitro et possédant des caractéristiques in vivo correspondant aux tissus sains équivalents sur les plans physiologique et fonctionnel. Nous examinons également les tendances actuelles en ingénierie tissulaire visant à adapter des échafaudages tissulaires, à promouvoir l'angiogenèse et à dégager une source optimale de cellules implantables. Enfin, nous décrivons plusieurs modalités thérapeu-tiques actuellement mises en application utilisant un échafaudage créé par ingénierie tissulaire. En dépit de progrès remarquables dans ce domaine en effervescence, les efforts déployés ne se sont pas encore traduits par une applicabilité clinique étendue. Des développements et des percées continus permettent d'être optimiste face au potentiel prodigieux de ce domaine.

Autologous urothelial cells transplantation onto a prefabricated capsular stent for tissue engineered ureteral reconstruction

“…Ureterostenosis may happen when disorganized scar formation occurs resulting from inability of native cells to regenerate over the defect region or inadequate blood supply before fibrosis takes place [10,11]. In order to deal with this situation, the prevailing concept in urinary tissue engineering is cell-based [34,35]. ECM is a complex mixture and difficult to simulate completely by artificial means, could serve as a micro-environment for cells survival.…”

Urinary Bladder vs Gastrointestinal Tissue: A Comparative Study of Their Biomechanical Properties for Urinary Tract Reconstruction

“…Ileal tissue is the most frequently utilised bowel segment for reconstructing the urinary bladder; however, it is considerably stiffer compared to stomach, transverse colon and descending colon tissue, figure 3. . However, porcine tissue samples were initially selected because their biomechanical properties closely resemble those of human tissue 11,12 . It is also arguable that mechanical properties may have been altered due to the ex vivo nature of the experimentation.…”

“…Knowledge on the biomechanical properties of normal bladder tissue and 'gold-standard' GI segments may improve development opportunities for more suitable urological reconstructive biomaterials in the future.Recently, there has been extensive interest in developing tissue-engineered urological scaffolds derived from biodegradable synthetic meshes and decellularized extracellular matrices (ECMs). ECMs are decellularized, biocompatible, biodegradable biomaterials usually derived from porcine organs11,12 . They are prepared by mechanical, chemical and enzymatic treatments to yield tissue that is minimally immunogenic and retains its basic structural elements13 .…”

Tissue Engineering of the Urinary Bladder: Current Concepts and Future Perspectives

“…Currently, the most commonly used synthetic polymers are poly-α-esters, such as poly(Llactide) (PLLA), PGA, and poly(lactide-co-glycolic acid) (PLGA). These polymers are biodegradable and exhibit good cell and tissue compatibility [24]. The advantage of using these scaffolds lies in the fact that their physical properties can be closely controlled [25].…”