منى محمد رضا محمد جعفر الشيخ راضي

The study involves preparing starch nanocrystals by acid hydrolysis of starch and to produce a new chemical crosslinking starch nanocrystals/gum Arabic blend in the presence of potassium persulfate (K2S2O8) as an initiator. The new materials were characterized and its potential utilization in controlled drug delivery and cancer therapy were investigated. Crosslinked starch nanocrystals/gum Arabic blends were loaded with hydroxyurea drug. The properties of starch nanocrystal was characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The starch nanocrystal /gum Arabic blends were analyzed in vitro drug release studies by using UV-vis spectroscopy. The swelling test and MTT assay were also investigated. The drug release and the swelling test were monitored at pH7.4 and pH4. XRD result showed that starch nanocrystal was the crystalline A-type. Starch nanocrystal showed a high degree of crystallinity compared with the native starch. The experimental results proved that starch nanocrystal/gum Arabic/hydroxyurea blends reduced the swell ability of blends which lead to slow release of hydroxyurea, and the rate of hydroxyurea release was significantly higher at pH7.4 than pH4, at constant incubation time. The swelling ratio and drug release were decreased by using starch nanocrystal/hydroxyurea while the swelling ratio and drug release using starch nanocrystal/gum Arabic/hydroxyurea blend were lowest. The results of vitro cytotoxicity study showed that the 100μg/ml hydroxyurea concentration killed ∼39% colorectal cancer cells while ∼27% of cells were killed by using starch nanocrystal/gum Arabic/hydroxyurea blends at the same concentration for 24hr of incubation. It was concluded that the hydroxyurea loaded starch nanocrystal/gum Arabic blend enhanced the controlled drug release system thereby, revealing a novels vehicle for cancer therapy.

Cancer is one of the most mortal diseases in the world .This work was planned to prepare a new chemical cross linking starch/gum Arabic hydrogel system in the presence of potassium persulfate(K2S2O8)as initiator, to describe the characteristic of the new material , and to investigate its potential utilizations in controlled drug delivery and cancer therapy. Crosslinked starch /gum Arabic hydrogel will be manufacture with changeable levels of starch and gum Arabic then were loaded with hydroxyurea. The structure of the native starch and starch/gum Arabic blends was characterized by FTIR, SEM. The starch and starch/gum Arabic blends were analyzed for in vitro drug release studies by using UV-vis spectroscopy. The swelling test, MTT assay were also investigated. The drug release and swelling test was monitored at pH 4 and pH7.4. The experimental results proved that the production of starch/gum Arabic blends was reduced the swell ability which lead to slow release of hydroxyurea, and the rate of hydroxyurea release was significantly higher at pH 7.4 than pH4, at constant incubation time. The swelling ratio and drug release of the blends was decreased with increasing gum Arabic levels. In vitro cytotoxicity study show the killing of 63% colorectal cancer cells at 500µg/ml of hydroxyurea concentration while the 49% destruction of cells require for the starch/gum Arabic/hydroxyurea blends at the same concentration and after 24hr of incubation. The sustained released of hydroxyurea-loaded starch/gum Arabic blend shows much better anticancer efficacy thereby, revealing a novels vehicle for the treatments of cancer.