Browsing by Subject "Tissue Engineering"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Open Access
    Bioartificial human corneas generated by tissue engineering. A historical and technical review
    (2026) Pascual-Vicente Crespo; José-Manuel García; Maria-Carmen Sánchez-Quevedo; Antonio Campos; Miguel Alaminos; Biología Celular e Histología
    Different types of bioartificial corneas have been generated by tissue engineering through combining cells, biomaterials, and bioactive molecules. Orthotypical corneal cells can be obtained from corneal biopsies, and include epithelial, stromal, and endothelial cells, whereas heterotypical cells are obtained from alternative cell sources with corneal differentiation potential, such as mesenchymal stem cells. In turn, two main types of biomaterials have been applied to corneal tissue engineering: those generated by the de-cellularization of natural tissues and biomaterials generated de novo using synthetic or natural biomaterials, especially collagen, fibrin, and agarose. Cells and biomaterials are combined with bioactive factors, inducing cell proliferation and differentiation. A review of previous studies revealed that most bioartificial corneas were not able to fulfill the complex requirements required for clinical translation, which include a thorough preclinical characterization, generation of the tissue as an advanced therapy medicinal product, a clinical research phase, and a final authorization by the European Medicines Agency or another competent regulatory agency. Most authorized products correspond to partial corneal substitutes consisting of one cell type associated or not with a scaffold, and only one product consisting of a human bioartificial cornea containing a fibrin-agarose scaffold and two corneal cell lineages (epithelial and stromal cells) called NANOULCOR was evaluated in patients in the context of an advanced therapy medicinal product. These findings confirm the existence of a bottleneck between basic and clinical research and suggest the need to implement novel clinical studies to develop new therapies that can improve the results of current corneal therapies.
  • Thumbnail Image
    Publication
    Open Access
    Differentiation of human mesenchymal stromal cells cultured on collagen sponges for cartilage repair
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Sanjurjo Rodríguez, Clara; Martínez Sánchez, Adela Helvia; Hermida Gómez, Tamara; Fuentes Boquete, Isaac; Díaz Prado, Silvia; Blanco, Francisco J.
    y. Aim: The aim of this study was to evaluate proliferation and chondrogenic differentiation of human bone-marrow mesenchymal stromal cells (hBMSCs) cultured on collagen biomaterials. Materials and Methods: hBMSCs were seeded on five different collagen (Col) sponges: C1C2 (types I and II Col), C1C2HS (types I and II Col plus heparan sulphate (HS)), C1C2CHS (types I and II Col plus chondroitin sulphate (CHS)), C1-OLH3 (type I Col plus low molecular weight heparin) and C1CHS (type I Col plus CHS). The resulting constructs were analyzed by histological and immunohistochemical staining, molecular biology and electron microscopy. Col released into culture media was measured by a dye-binding method. Results: hBMSCs on biomaterials C1C2, C1C2HS and C1C2CHS had more capacity to attach, proliferate and synthesize Col II and proteoglycans in the extracellular matrix (ECM) than on C1-OLH3 and C1CHS. The presence of aggrecan was detected only at the gene level. Total Col liberated by the cells in the supernatants in all scaffold cultures was detected. The level of Col I in the ECM was lower in C1-OLH3 and that of Col II was highest in C1C2 and C1C2HS. Electron microscopy showed differently shaped cells, from rounded to flattened, in all constructs. Col fibers in bundles were observed in C1C2CHS by transmission electron microscopy. Conclusions: The results show that Col I and Col II (C1C2, C1C2HS and C1C2CHS) biomaterials allowed cell proliferation and chondrogenic-like differentiation of hBMSCs at an early stage. Constructs cultured on C1C2HS and C1C2CHS showed better cartilage-like phenotype than the other ones.
  • Thumbnail Image
    Publication
    Open Access
    The multilayered structure of the human corpus spongiosum
    (2018) De Graaf, P.; Ramadan, R.; Linssen, E.C.; Staller, N.A.; Hendrickx, A.P.A.; Pigot, G.L.S.; Meuleman, E.J.H.; Bouman, M.; Özer, M.; Bosch, J.L.H.R.; de Kort, L.M.O.
    Purpose. Urethral reconstruction is performed in patients with urethral strictures or for correction of congenital disorders. In the case of shortage of tissue, engineered tissue may enhance urethral reconstruction. As the corpus spongiosum (CS) is important in supporting the function of the urethra, tissue engineering of the urethra should be combined with reconstruction of a CS. For that purpose, detailed knowledge of the composition of the CS, more specifically its extracellular matrix (ECM) and vascularization is needed for scaffold design. The objective of this study is to analyze the microarchitecture of the CS through (immuno) histology and scanning electron microscopy (SEM). Methods. The CS including the urethra of patients undergoing male-to-female genital confirming surgery was harvested. This CS was fixed and processed for either (immuno) histology or for SEM. Results. Four layers could be distinguished in the CS; first a transition zone from urethra epithelium to a collagen rich layer, which was highly vascularized, followed by a second, elastin rich layer. The third layer was formed by veins, arteries and vascular spaces and the last layer showed the transition from this vascular rich region to the collagen rich tunica albuginea. In this layer collagen bundles intertwined with elastic fibres. In the CS different components of the ECM were visible and distinguishable. Conclusion. This study provides novel and detailed information on the microarchitecture of the CS and the distribution of vascularization, which is important for scaffold design in tissue engineering.