RESUMO
A composite is a material made of more than one component, and the bond between the components is on a scale larger than the atomic scale. The objective of the present study was to synthesize and perform the structural characterization and biological evaluation of a new biocomposite (BCO) based on a novel combination of an organic and an inorganic phase, for bone tissue engineering applications. The organic phase consisted of Wharton's jelly (WJ), which was obtained from embryonic tissue following a protocol developed by our laboratory. The inorganic phase consisted of bioceramic particles (BC), produced by sintering hydroxyapatite (HA) with ß- tricalcium phosphate (ß-TCP), and bioactive glass particles (BG). Each phase of the BCO was fully characterized by SEM, EDS, XRD, and FTIR. Biocompatibility was evaluated in vivo in the tibiae of Wistar rats (n = 40). Histological evaluation was performed at 0, 1, 7, 14, 30, and 60 days. XRD showed the phases corresponding to HA and ß-TCP, whereas diffractogram of BG showed it to have an amorphous structure. EDS showed mainly Si and Na, Ca, P in BG, and Ca and P in HA and ß-TCP. FTIR identified bonds between the organic and inorganic phases. From a mechanical viewpoint, the composite showed high flexural strength of 40.3 ± 0.8 MPa. The synthesized BCO exhibited adequate biocompatibility as shown by formation of lamellar type bone linked by BG and BC particles. The biomaterial presented here showed excellent mechanical and biocompatibility properties for its potential clinical use. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1034-1045, 2017.
Assuntos
Fosfatos de Cálcio/química , Durapatita/química , Teste de Materiais , Engenharia Tecidual , Alicerces Teciduais/química , Geleia de Wharton/química , Animais , Masculino , Ratos , Ratos WistarRESUMO
Disorders in skin wound healing are a major health problem that requires the development of innovative treatments. The use of biomaterials as an alternative of skin replacement has become relevant, but its use is still limited due to poor vascularization inside the scaffolds, resulting in insufficient oxygen and growth factors at the wound site. In this study, we have developed a cell-based wound therapy consisting of the application of collagen-based dermal scaffolds containing mesenchymal stem cells from Wharton's jelly (WJ-MSC) in an immunocompetent mouse model of angiogenesis. From our comparative study on the secretion profile between WJ-MSC and adipose tissue-derived MSC, we found a stronger expression of several well-characterized growth factors, such as VEGF-A, angiopoietin-1 and aFGF, which are directly linked to angiogenesis, in the culture supernatant of WJ-MSC, both on monolayer and 3D culture conditions. WJ-MSC proved to be angiogenic both in vitro and in vivo, through tubule formation and CAM assays, respectively. Moreover, WJ-MSC consistently improved the healing response in vivo in a mouse model of human-like dermal repair, by triggering angiogenesis and further providing a suitable matrix for wound repair, without altering the inflammatory response in the animals. Since these cells can be easily isolated, cultured with high expansion rates and cryopreserved, they represent an attractive stem cell source for their use in allogeneic cell transplant and tissue engineering.