Investigation of the application of polylactic acid-calcium phosphate composite materials as novel periodontal barrier membranes

QH301 Biology;TJ Mechanical engineering and machinery

Talal, Ahmed ; Tanner, Kathleen

University:University of Glasgow

Department:School of Engineering

关键词: polylactic acid, calcium phosphate, periodontal barrier membranes;   

Others  :  http://theses.gla.ac.uk/1223/1/2009talalphd.pdf

来源: University of Glasgow

【 摘 要 】

The ultimate aim of periodontal treatment is to regenerate the tissue lost during the disease process, thereby restoring the aesthetics and function of the periodontium. Guided tissue regeneration (GTR) is one technique that is used clinically to promote tissue regeneration.The technique employs a membrane to create space in the appropriate surgical site to produce periodontal regeneration.However there may be considerable potential to improve the outcomes of this technique by development of novel membrane materials. The aim of the studies described in this thesis was to investigate the potential of polylactic acid-calcium phosphate (PLA-Ca P) composite materials to be developed into a GTR membrane with increased potential for producing periodontal regeneration.Ca P materials included nano-hydroxyapatite (n-HA) and ß tri-calcium phosphate (ß-TCP).PLA-Ca P composite films were produced by the solvent casting method. The Ca P powders and the PLA-Ca P composite films were characterized.The degradation of PLA-Ca P composites was analysed in phosphate buffer saline (PBS).The bioactive potential of the composite films was determined in simulated body fluid (SBF).The growth and differentiation of PDL cells and osteoblasts were assessed on PLA-nHA composite films and the ability of these films to carry platelet derived growth factor (PDGF) and its effect on osteoblast growth was investigated.Further, fibre reinforced PLA-HA composite membranes were fabricated and their mechanical strength and kinetics of protein interactions were investigated. Finally mandibular alveolar bone profiles were analyzed to define the possible shapes required for manufacture of GTR membranes. Results showed that Ca P decreased the degradation and increased the bioactivity of the PLA-Ca P composite films.The cell proliferation on composite films containing 10 wt % nHA was high when compared to PLA films. However, cell proliferation decreased with increase in nHA concentration. The highest alkaline phosphate activity (ALP) was shown by cells on composite films containing 70 wt % nHA. The PDGF added to the PLA-nHA composite films retained its activity and increased the proliferation of osteoblasts. The flexural strength was high for the fibre reinforced PLA-HA composite membranes, containing maximum number of PLA fibres laid at 0°. The fibre reinforced membranes containing HA showed gradual and sustained protein release compared to fibre reinforced membranes without HA. The analysis of alveolar bone profiles of different patients showed marked similarities between each other, suggesting that only a few membrane shapes may be required to fit most patients in clinical use.These studies demonstrate the potential of fibre reinforced PLA-HA composite material to be used for the production of preshaped GTR membranes with favourable properties to increase periodontal regeneration