RESUMO
Here, scaffolds as cell and tissue carriers are approached from an engineering point of view, emphasizing material superstructuring in the design of supports. Superstructure engineering provides optimal spatial and nutritional conditions for cell maintenance by the arrangement of structural elements (e.g. pores or fibres) so as to vary the order of cell to cell contact. This approach is illustrated in the design of several scaffolds: knitted fabrics as three-dimensional superstructures for optimized osteosynthesis implants, a new injectable open porous implant system, an angiopolar non-degradable ceramic cell carrier, and an injectable or microsurgically implantable entangled carrier system. The implications for tissue engineering are discussed.
Assuntos
Materiais Biocompatíveis/normas , Transplante de Células/métodos , Transplante de Tecidos/métodos , Anisotropia , Benzofenonas , Materiais Biocompatíveis/química , Biotecnologia , Cimentos Ósseos/química , Comunicação Celular , Cerâmica/normas , Cetonas/química , Metilmetacrilatos/química , Microscopia Eletrônica de Varredura , Peso Molecular , Polietilenoglicóis/química , Polímeros , Álcool de Polivinil/química , Porosidade , Próteses e ImplantesRESUMO
Microporous alumina was used to develop implantable cell carriers shaped as a hollow-sphere with a central opening to allow ingrowth of vascularised tissues. The carriers were produced by suspending the ceramic raw materials in water, homogenising and dropping the resulting slurry onto a heated plate (hot plate moulding, HPM). Morphological characteristics of the cell carriers were investigated by SEM and optical microscopy. Produced carriers had an average diameter of 4.9 mm. The material was highly porous (56 +/- 8%). For in vivo testing the cell carriers were implanted into abdominal wall of Zur: SIV rats for up to 50 weeks and investigated by light microscopy, SEM and TEM. The surface of the hollow carriers was in close contact with unirritated muscle tissue; no inflammation or capsule formation was observed. Loose connective tissue had grown into the hollow cell carrier, and after prolonged implantation >20 weeks adipocytes were observed. The absence of scar tissue formation around the implant and the vitality within the cavity of the hollow carriers indicate that porous alumina may be used for cell transplantation devices.
Assuntos
Óxido de Alumínio , Materiais Biocompatíveis , Transplante de Células/métodos , Cerâmica , Implantes Experimentais , Animais , Células do Tecido Conjuntivo/transplante , Células do Tecido Conjuntivo/ultraestrutura , Feminino , Fibroblastos/transplante , Fibroblastos/ultraestrutura , Leucócitos Mononucleares/transplante , Leucócitos Mononucleares/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Varredura , Porosidade , RatosRESUMO
Biomaterials and related process engineering in order to obtain optimal surface and structural biocompatibility of implants and devices are presented. Vital-avital composites for tissue engineering, cell culture models, porous ceramics and degradable polymers are introduced as examples. Emphasis is laid on the conversion of basic research results into clinical applications and on the exchange of technologies from the non-medical into the medical field and vice versa.