甲氨蝶呤-G4.0聚酰胺胺树状大分子体外释放初探

Preliminary study on methotrexate-G4.0 PAMAM dendrimer release in vitro

目的探讨新型纳米级生物材料G4 0聚酰胺胺(polyamidoamine ,PAMAM )树状大分子对抗癌药物甲氨蝶呤(methotrexate ,MTX)体外释放的影响及释药机理。方法用紫外分光光度法测定G4 0聚酰胺胺树状大分子与甲氨蝶呤复合物在不同浓度和离子强度缓冲溶液( 37℃、pH =7 4 )中甲氨蝶呤的释放行为。结果确定了一个G4 0聚酰胺胺树状大分子可复合14个甲氨蝶呤,在37℃、pH为7 4的10mmol·L-1Tris HCl缓冲溶液中释放甲氨蝶呤80 %需2 0 0h ,但这种缓释作用随离子强度的增加而减弱。结论G4 0聚酰胺胺树状大分子对甲氨蝶呤具有明显的缓释作用,二者的复合作用是聚酰胺胺树状大分子的氨基阳离子与甲氨蝶呤的羧基阴离子之间形成的静电作用导致的。

Objective To investigate the effect of G4.0 polyamidoamine (PAMAM) on in vitro release of encapsulated anticancer drug methotrexate (MTX).Method UV was employed to monitor the in vitro release of MTX from G4.0 PAMAM in different buffers.Results Each G4.0 PAMAM could attach about 14 MTX molecules and in vitro release rate of those attached MTX molecules is much slower than that of the free MTX.However,such controlled release is effected by the ionic strength of the buffer.Conclusion G4.0 PAMAM is proved to have controlled release ability for MTX because of the electrostatic interation between PAMAM and MTX.