DSPE-PEG2000-NH2和甲氨蝶呤的羧基发生酰胺化反应的实验使用方法:

Synthesis & characterization Of DSPE-PEG-MTXDSPE-PEG-MTX was synthesized using DSPEPEG2000-NH2, and MTX using a protocol describedpreviously with minor modifications [36]. BriefyMTX (8.2 mg, 18 umol), dicyclohexylcarbodimide(DCC, 3.7 mg, 18 μmol) and N-hydroxysuccinimide(NHS, 2.1 mg, 18 μmol) were dissolved in anhydrousDMSO (400 ul). Thirty minutes after reaction, theresultant solution was added to a DSO solution(400 μl) containing TEA Of DSPE-PEG2000-NH2(10.1 mg, 3.6 umol). Under a nitrogen atmosphere,the resultant mixture was allowed to react for 72 hat room temperature with continuous stirring. Theresulting mixture was filtered to remove the white pre-cipitation of dicylcohexylurea and precipitated in icecold ether. The crude precipitate was further washedby dichloromethanefor six-times and then drieddialyzed againstunder vacuum. The product wasPBS solution for 24 h and against water for further24 h. The solution was passed through 0.22 um filterto remove insoluble traces, lyophilized for 24 h andstored at -20°C。