Abstract:

Objective Dendrimer, a new class polymeric materials of highly branched, symmetric and nanoscale, are considered as potential drug delivery vehicle for their particular structure and character. The capability of G4.0 Polyamidoamie (PAMAM) dendrimer as anticancer drug methotrexate (MTX) carrier were studied.Methods UV has been employed to monitor the in vitro release of MTX from G4.0 PAMAM in different buffers. We discuss mechanism of complex by ¹H and ¹³ C NMR.Results Each G4.0 PAMAM could conjugated 14 MTX molecules; An electronic interaction between G4.0 PAMAM primary amine groups and MTX carboxylic groups was demonstrated by ¹H and ¹³ C NMR. It took 200 h to release 80% MTX from the G4.0 PAMAM-MTX complex in 10 mmol/L, pH 7.4 Tris-HCl buffer solution, while 20 h for pure MTX under same condition; With the increasing of ionic strength in Tris-HCl buffer solution, the G4.0 PAMAM-MTX complex released MTX fast and the stability of the G4.0 PAMAM-MTX system decreased.Conclusion ¹H and ¹³ C NMR data demonstrated the interaction between G4.0 PAMAM dendrimer primary amine groups and MTX carboxylic groups is due to the electrostatic force; G4.0 PAMAM dendrimer could load 14 MTX molecules; the controlled release ability of G4.0 PAMAM-MTX complex was 10 times better than the control (pure MTX) in 10 mmol/L(pH 7.4) Tris-HCl buffer solution.

Key words: G4.0PAMAM, methotrexate (MTX), conjugation, release