Young-Kook Shin

Hybrid Nanogels for Sustainable Positive Thermosensitive Drug Release

A hybrid nanogel has been developed based on interpenetrating networks of thermosensitive poly(N-isopropylacrylamide) gels and tailored nanoporous silica. A sustainable positive thermo-responsive drug release profile is obtained. When the temperature rises, the polymer gel shrinks, squeezing the drug into the porous channels, and at the same time, opening the pores to the outside media. The drug slowly diffuses out of the porous channels. The overall release rate can be adjusted by changing the composition of the nanogel.

Synthesis and evaluation of antitumor activity of 2- and 6-[(1,3-benzothiazol-2-yl)aminomethyl]-5,8-dimethoxy-1,4-naphthoquinone derivatives

Abstract2- or 6-Substituted BZT-N derivatives were synthesized, and their cytotoxic activity against cancer L1210 and SNU-1 cells was examined. The antitumor action was also assessed in mice bearing S-180 cells in peritoneal cavity. In a comparison, it was found that 6-substituted BZT-N derivatives exhibited higher potencies in both bioactivities than 2-substituted BZT-N derivatives against L1210 cells inin vitro and S-180in vitro tests exception of compound36. Interestingly, it was observed that 2-substituted compound36, which has methyl group at R1 position, exhibited a better antitumor activity than 6-substituted compounds against L1210 and SNU-1in vitro. The ED50 value of 2-substituted compound36 against L1210 was found to be comparable to the ED50 value of adriamycin and was even better against the solid cancer cell line SNU-1. It was also observed that 2-substituted compound36 showed better antitumor activity in mice bearing S-180 cells in the peritoneal cavity. The T/C (%) value of 2-substituted compound36 was similar to that of adriamycin. Quantitative structure-activity relationship (QSAR) tests reveal that the experimental ED50 values against SNU-1 closely correlate with both the calculated HOMO energies(Ehomo) and the measured1H-NMR chemical shift of 3-H (δH). The results suggests that a compound having higherEHOmo and δH values usually should have a lower ED50 (SNU-1) value.