| Summary: | 碩士 === 中原大學 === 醫學工程學系 === 83 === Polyesters based on lactic acid have been reported safty and
biodegradation in the human beings for two decades. The
greatest advantage of the material is its degradatio only
conducted by the hydrolysis, where the ester backbones are
supposed to be unchained in the aqueous condition. The final
degradable product are carbon dioxide and water that can be
metabolized and digest- ed in the physiological environment.
The goal of this study was aim to develope a composite combined
with poly-DL-lactide(PDLLA) and tricalcium phosphate(TCP)
ceramic particles as orthopaedic application. The TCP
particles in a range of 0-60wt%(with 5wt% increment) were doped
into the PDLLA matrix for the reinforcement, which were
prepared by the melting and hot pressing technique. The
basic mechanical strength, biodegradable behavior, and bio-
logical response of the composites will be investigated in the
study. Various techniques, such as pH meter, UV, FTIR, XRD
etc., were used to examine and record the degradable process
of the composites soaked in the Ringer''s solution for 1-12
weeks. The cell culture, rats subcutaneous implant and rabbit
femur con- dyle fracture fixation test were used to
evaluatethe cytotocity , tissue compatability, and effects of
bone fracture fixation of the composites, respectively, The
histological observation and x-ray photography were applied
for investigating assistance. The mechanical strength of the
composites initially with TCP additions upto 50wt%,
thgereafter, showed no significant differ- ence(p>0.05). The
composite with 50wt% TCP addition showed high mechanical
strength and had a great agreement with cortical bone in
elastic modulus of 37MPa. The weight loss of the pure PDLLA
soaked in the Ringer''s solution was started at 4 weeks and
reac- hed to 80wt% after 12 weeks. The composites compared
with pure PDLLA, however, showed no apparent evidence for
degradation after soaked for 12 weeks.
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