Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 101 === The simple preparation strategy and self-assembly behavior of poly(L-lysine)-graft-decanoyl (PLD) and poly(L-lysine)-graft-tetradecanoyl (PLT) have been demonstrated. In the study, we synthesized three different poly(L-lysine) (PLL) chain length (Mw = 97800, 40600, 19100) and incorporated with two different acyl chain in various substitution levels by reacting with acyl anhydride. The experimental data revealed that the interplay between hydrophobic fatty chain and the secondary conformational changes determined the self-assembed nanostructures of PLD and PLT. The micellar nanostructures were formed with the mean sizes between 70 and 325 nm in acidic and neutral aqueous solution. The critical aggregation concentration (CAC) were in the range of 5.2×10-2~1.0×10-3 mg/mL, which is smaller than our previous report on poly(L-lysine)-graft-hexanoyl (PLH). The chain conformational changes were observed the increase of relative content of helix, sheet and turn conformations as a result of incorporation of acyl chains and different pH value. The as-prepared particles were employed for natural hydrophobic drug encapsulation. The curcumin were used as a model drug with the encapsulation efficiency higher than 90% and loading capacity up to 43%, which is higher than most of the related studies. The sizes of curcumin-loaded micelles were range between 90 and 165 nm, and would increase to 100~190 nm when further crosslinking by genipin. With versatility of this synthesis strategy, additional functionality can be incorporated on PLD and PLT, which can allow these amphiphilic copolypeptides to be useful as targeted drug carriers, nanoencapsulants in the biomedical fields.
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