本研究利用燒結的方法製作多孔性的氫氧基磷灰石(HA)燒結體,加入聚乳酸(PLLA)及由高分子量聚乳酸降解的乳酸寡聚物製作成PLLA/HA複合材,以作為硬組織生物可吸收性修補材之用。目前得到,使用砂糖及食鹽當作填充劑,以HA比砂糖比食鹽為1比1比1,5-45 kgf/cm2的壓力壓製成形,再以220°C下加熱使砂糖溶解,並且在1345°C燒結10小時的燒結物的強度以及孔隙度為最佳。高分子聚乳酸會隨著酸的濃度以及降解時間而分子量降低,分子數目上升,結果可由黏度值、GPC、DSC、FT-IR、X-ray、及接觸角的測定證實。從毒性測試的結果可知未洗過的HA對細胞造成的毒性最高,而使用氯仿洗過的HA毒性最低。由廣角X-ray的結果顯示,HA的燒結時間越久,或是成型壓力越大,其結晶程度越高。PLLA/HA複合材的機械性質測定結果顯示加入的聚乳酸濃度越高,其機械性質越強。
The porously sintered hydroxyapatite (HA) and poly(L-lactide) (PLLA) oligomer were used to prepare a series porous poly(L-lactide)/hydroxyapatide (PLLA/HA) composites as a biodegradable hard tissue repair material, and its physical-chemical properties were studied in this investigation. The used PLLA oligomer, mentioned above, was prepared via acidic hydrolytic reaction. The HA sinter with optimal strength and porosity could be obtained when HA was mixed with 1 of fold sucrose which was used as filler while binder and 1 of fold salt as filler, pressed under 5-45 kgf/cm2 force, dissolved the sucrose at 220°C, and then sintered under 1345°C for 10h. The all results of viscosity, gel permeation chromatography, thermal properties, IR spectra, X-ray diffraction pattern, and contact angle wholly reveal that the PLLA molecular weight decreasing with the acid amount and degradation time increasing. HA without any purification have a highest toxicity and HA washed with chloroform have a lowest toxicity against gingival fibroblast were found. The results of X-ray diffraction pattern present that the crystallinity increasing with sintered time and the pressure. The MTS data appear the more PLLA the higher mechanical strength.