聚乳酸甘醇酸（poly(lactic-co-glycolic acid)，PLGA）為FDA認可並運用在藥物載體方面行之有年。PLGA是一種具有無毒性、良好生物相容性（biocompatible）和生物降解性（biodegradable）的高分子材料。PLGA可以透過體內的檸檬酸循環（citric acid cycle）將乳酸和甘醇酸轉化為二氧化碳和水而排出體外。
本實驗室合成出五個鉑化合物，包括sulfoplatin和其衍生物。分別將sulfoplatin中的DMSO配位基的部分替換為sulindac （2）和sulfinpyrazone（3），還有將sulfoplatin中的 -Cl配位基的部分替換為1-(2-tetrahydrofuryl)-5-fluorouracil ( tegafur )（4）和5-fluorouracil （5-FU）（5）等5個鉑化合物。利用24.4–40.6KD、40.6–57.8KD和49.67–69.58KD三種不同分子量大小的PLGA做為包覆材料，並利用奈米沉澱法（nanoprecipitation）合成具有奈米大小且包含鉑化合物的PLGA，利用紫外暨可見光譜分析儀計算產率（yield）、藥物含量（drug content）和有效包覆率（encapsulation efficiency，EE）。其數據分佈yield：1.54%–12.3%；drug content：0.915%–14.6%；EE值為：0.337%–23.0 %。

不同分子量大小的PLGA和鉑化合物會影響EE值。我們發現其EE值與鉑化合物及PLGA材料之關係有兩個趨勢，其一以分子量較大的PLGA包覆有鉑化合物可得較佳的EE值；同分子量大小的PLGA包覆脂溶性佳的鉑化合物有較佳的EE值。Drug content值會受到鉑化合物物理性質的影響，以脂溶性佳的鉑化合物有較高的drug content值。另一方面，形成奈米粒子之效率yield 值受到回收奈米粒子方法的影響，包括離心時間、轉速和次數等。在49.67–69.58KD分子量大小的PLGA且包含sulindac的鉑化合物2表現最好，其EE值為23.0%，drug content和yield分別為14.6%與5.65%。
進行提高奈米粒子EE值的實驗中，當增加鉑化合物對PLGA重量比例時(drug/polymer, w/w % )，drug content值會提高，但對EE值和產率沒有明顯的影響。產率較高時EE值也較高，所以有效地回收形成的奈米粒子可有助於EE值的提高。以49.67–69.58KD分子量大小的PLGA包覆含有sulfinpyrazone鉑化合物3，當藥物量為10.0%時，表現較佳，其EE值為37.6%，包覆率上升，drug content和yield為21.5%與17.6%。
另外，當改變有機溶劑對水溶劑的比例（organic to aqueous phase ratio）時，提高有機溶劑的比例會增加drug content值，若降低有機溶劑則會有助於EE值和yield的提升。以49.67–69.58KD分子量大小的PLGA包覆含有sulindac的鉑化合物2，當有機溶劑對水溶劑的比例為1：20，表現較佳，其EE值為30.2%，drug content和yield為8.19%與18.3%。
藉由改變實驗條件下，可有效提升藥物包覆率。透過我們的實驗結果，可用於未來包覆鉑藥物之參考資料，增加藥物投遞效果，以提昇癌症治療效果。

Poly (lactide-co-glycolide) (PLGA), one of the FDA approved polymer, has widely applied in the drug delivery system for many years. PLGA is a non-toxicity, good biocompatibility and biodegradability polymer. The PLGA polymer biodegrades into lactic and glycolic acids. Lactic acid enters the tricarboxylic acid cycle and is metabolized and subsequently eliminated from the body as carbon dioxide and water. Our group synthesizes five platinum complexes, including sulfoplatin and its derivative, PtCl(sulindac-S=O)[η2-C5H4SN(O)], PtCl(sulfinpyrazone)[η2- C5H4SN(O)], Pt(1-(2-tetrahydrofuryl)-5-fluorouracil-3-yl)(DMSO)[η2-C5H4S- N(O)] and [Κ-(5-fluorouracil-3-yl)]Pt2(DMSO)2[η2-C5H4SN(O)]2. In this study we applied three kinds of molecular weight size polymer and nanoprecipitation method to prepare PLGA nanoparticles loaded with platinum complexes. The yield, drug content, entrapment efficiency determined by UV-Vis spectrophotometer. The yield were 1.54%–12.3%; drug content were 0.915%–14.6% and entrapment efficiency were 0.337%–23.0%. The effect of different size molecular weight polymer and platinum complexes on entrapment efficiency was investigated. The larger molecular weight polymer and more lipophilic platinum complexes has the better entrapment efficiency. The physical property of platinum complexes has the affect on drug content. The nanoparticle recovery step however needs further mprovements, since bridges between particles which cause focculation could be observed. It was found that a molecular weight of 49.67-69.58KD and loaded with platinum complex 2 PLGA nanoparticles has the yield 5.65%, drug content 14.6% and entrapment efficiency 23.0%. Approaches investigated for the enhancement of drug entrapment efficiency included the infuence of initial platinum complexes content and organic to aqueous phase volume ratio. Increase in platinum complexes content resulted in increase in drug content, but no effect on yield and entrapment efficiency. It was found that a molecular weight of 49.67-69.58KD and loaded with platinum complex 3 PLGA nanoparticles, when platinum complexes content was 10.0% has the yield 17.6%, drug content 21.5% and entrapment efficiency 37.6%. Increase in organic to aqueous phase volume ratio resulted in increase in drug content but decrease in yield and entrapment effciency. It was found that a molecular weight of 49.67-69.58KD and loaded with platinum complex 2 PLGA nanoparticles, when organic to aqueous phase volume ratio was 0.05 has the yield 17.6%, drug content 21.5% and entrapment efficiency 37.6%. The formulation variable could be exploited in order to enhance the incorporation of platinum complexes into PLGA nanoparticles. Hence the developed platinum complexes loaded PLGA is suitable for drug delivery in treatment of cancer.

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