| Summary: | 碩士 === 國立臺北科技大學 === 化學工程與生物科技系化學工程碩士班（碩士在職專班） === 105 === For people aged 50 years or over, osteoporosis caused by spinal compression fractures is a common cause of pain. In recent years, percutaneous vertebroplasty and percutaneus balloon kyphoplasty become the most accepted treatments for these fractures. The main concern with percutaneous kyphoplasty is high incidence of bone cement leakage and other resulting complications; therefore, this experiment aimed to make a biodegradable film casing to replace the conventional balloon to improve the leakage problem.
Polylactic acid is a biomaterial with good bioabsorbability, biodegradability and good environmental affinity, as a polymeric material, it attracts considerable attention in recent years. Poly-L-lactic acid (PLLA), an optical isomer of polylactic acid, is often used in different industrial or medical applications. Tricalcium silicate (C3S) is the main component of Portland cement, with good biocompatibility and rapid hydration ability, widely used in biomaterials. PLLA was first dissolved in chloroform, and calcium silicate was then added to the polymer solution. The composite film with anti-permeation property was prepared by the solution casting method.
In this study, we first explored the effects of different concentrations of tricalcium silicate (C3S) on the mechanical properties of the film. It was found that the addition of 1wt% C3S powder worked best in poly-L-lactic acid solution balancing all parameters. With an increase of C3S content, the Young s modulus of the composite film also increased. The maximum stress of PLLA/C3S film was 13.03 MPa and the fractural strain was 157%. TGA and DSC thermal properties of the film showed no residual chloroform on the film, the thermal cracking temperatures of both PLLA and PLLA/C3S films were around 385°C. The addition of C3S to the film was non-homogeneous nucleation. The cold crystallization peak appeared before Tg point could promote the film to the melting point state. The film was immersed in artificial simulated body fluid (SBF), whereas the pH value was maintained at about 7.4, and the apatite deposited on the material after 8 hours of soaking. Release of silicon from PLLA/C3S film was 15 ppm after 21 days of soaking in SBF. By considering the mechanical properties, in vitro test, cell experiments and other experimental results of the material, this PLLA/C3S film has good biocompatible and anti-leakage potential to be applied to percutaneous balloon kyphoplasty.
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