RESUMEN
The major goal of bone tissue engineering is to develop bioconstructs which substitute the functionality of damaged natural bone structures as much as possible if critical-sized defects occur. Scaffolds that mimic the structure and composition of bone tissue and cells play a pivotal role in bone tissue engineering applications. First, composition, properties and in vivo synthesis of bone tissue are presented for the understanding of bone formation. Second, potential sources of osteoprogenitor cells have been investigated for their capacity to induce bone repair and regeneration. Third, taking into account that the main property to qualify one scaffold as a future bioconstruct for bone tissue engineering is the biocompatibility, the assessments which prove it are reviewed in this paper. Forth, various types of natural polymer- based scaffolds consisting in proteins, polysaccharides, minerals, growth factors etc, are discussed, and interaction between scaffolds and cells which proved bone tissue engineering concept are highlighted. Finally, the future perspectives of natural polymer-based scaffolds for bone tissue engineering are considered.
Asunto(s)
Materiales Biomiméticos/farmacología , Huesos/efectos de los fármacos , Polímeros/farmacología , Ingeniería de Tejidos/métodos , Andamios del Tejido , Materiales Biomiméticos/química , Huesos/lesiones , Carbonato de Calcio/química , Carbonato de Calcio/farmacología , Diferenciación Celular , Quitosano/química , Quitosano/farmacología , Durapatita/química , Durapatita/farmacología , Humanos , Ensayo de Materiales , Osteoblastos/citología , Osteoblastos/fisiología , Osteogénesis/genética , Polímeros/química , Dióxido de Silicio/química , Dióxido de Silicio/farmacología , Células Madre/citología , Células Madre/fisiologíaRESUMEN
Various TiO2 nanofibers on Ti surface have been fabricated via electrospinning and calcination. Due to different elaboration conditions the electrospun fibers have different surface feature morphologies, characterized by scanning electronic microscopy, surface roughness, and contact angle measurements. The results have indicated that the average sample diameters are between 32 and 44 nm, roughness between 61 and 416 nm, and all samples are hydrophilic. As biological evaluation, cell culture with MG63 cell line originally derived from a human osteosarcoma was performed and correlation between nanofibers elaboration, properties and cell response was established. The cell adherence and growth are more evident on Ti samples with more aligned fibers, higher roughness and strong hydrophilic character and such fibers have been elaborated with a high speed rotating cylinder collector, confirming the idea that nanostructure elaboration conditions guide the cells' growth.
Asunto(s)
Nanofibras/química , Titanio/química , Citoesqueleto de Actina/química , Citoesqueleto de Actina/metabolismo , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Nanofibras/toxicidad , Nanofibras/ultraestructura , Propiedades de SuperficieRESUMEN
Various TiO2 nanotubes on Ti50Zr alloy have been fabricated via a two step anodization method in glycol with 15vol.% H2O and 0.2M NH4F under anodization controlled voltages of 15, 30 and 45V. A new sonication treatment in deionized water with three steps and total sonication time as 1min was performed after the first anodization step in order to remove the oxide layer grown during 2h. The second step of anodization was for 1h and took place at the same conditions. The role of removed layer as a nano-prepatterned surface was evidenced in the formation of highly ordered nanotubular structures and morphological features were analyzed by SEM, AFM and surface wettability. The voltage-controlled anodization leads to various nanoarhitectures, with diameters in between 20 and 80nm. As biological assay, cell culture tests with MG63 cell line originally derived from a human osteosarcoma were performed. A correlation between nanostructure morphological properties as a result of voltage-controlled anodization and cell response was established.
Asunto(s)
Aleaciones/química , Materiales Biocompatibles/química , Proliferación Celular/fisiología , Nanotecnología/métodos , Nanotubos/química , Actinas/genética , Adhesión Celular/fisiología , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Supervivencia Celular/fisiología , Expresión Génica , Humanos , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteocalcina/genética , Osteonectina/genética , Tamaño de la Partícula , Propiedades de Superficie , Titanio/química , Humectabilidad , Zinc/químicaRESUMEN
Osteoblasts are specialized mesenchyme-derived cells accountable for bone synthesis, remodelling and healing. Differentiation of osteoblasts from mesenchymal stem cells (MSC) towards osteocytes is a multi-step process strictly controlled by various genes, transcription factors and signalling proteins. The aim of this review is to provide an update on the nature of bone-forming osteoblastic cells, highlighting recent data on MSC-osteoblast-osteocyte transformation from a molecular perspective and to discuss osteoblast malfunctions in various bone diseases. We present here the consecutive stages occurring in the differentiation of osteoblasts from MSC, the transcription factors involved and the role of miRNAs in the process. Recent data concerning the pathogenic mechanisms underlying the loss of bone mass and architecture caused by malfunctions in the synthetic activity and metabolism of osteoblasts in osteoporosis, osteogenesis imperfecta, osteoarthritis and rheumatoid arthritis are discussed. The newly acquired knowledge of the ontogeny of osteoblasts will assist in unravelling the abnormalities taking place during their differentiation and will facilitate the prevention and/or treatment of bone diseases by therapy directed against altered molecules and mechanisms.