Study On Carbon Black Oxidized By Plasma Grafting Antitumour Etoposide (VP-16)

In this paper,the nanometer carbon blacks of high oxygenous functional groups were used for carrier of target antitumor medicine,it was studied that the nanometer carbon black was oxidized by two ways and that the oxidized carbon black was used to graft antitumour etoposide(VP-16) by two ways also. Firstly,it was contrastively studied that the nanometer carbon black was oxidized by two kind of oxygen plasma:radio frequency discharge(RF) and dielectric barrier discharge(DBD).The results of analysis showed that the DBD was more suitable for oxidizing carbon black than RF. Because carbon black oxidized by DBD had a lot of single oxygenous functional group,carboxyl,which could be used to graft antitumour medicine and could be well dispersed in water. Moreover the operations of DBD are very simple and could be controlled easily. In this paper the optimal conditions of DBD were 0.5g carbon black, 19.0KV AC high electric pressure, 625ml/min oxygen gas flow and two hour discharge time. Next,according to the performances of oxidized carbon black as well as the chemical structure and properties of etoposide(VP-16),two grafting routes:pyridine route and Hemxamethyl phosphoramide(HAMPT) route were selected. Pyridine route was that the surface carboxyl of oxidized carbon black was acylchloridized by thionychloride and then was esterified in pyridine to graft antitumour etoposide; HAMPT route was that the surface carboxyl of oxidized carbon black was acylchloridized by thionychloride and then was esterified in HAMPT to graft antitumour etoposide. The results of IR spectrometry and element analysis showed the HAMPT route was more suitable for grafting medicine etoposide than Pyridine route. The optimum conditions of HAMPT were: acylchlorine temperature—50~55℃,acyl temperature—RT,n (carbon black carboxyl ) : n (etoposide) =1 :0.5. The yield of HAMPT was 33%.