ABSTRACT
Accurate tumor targeting, deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine. To achieve these requirements, a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer (d-SN38)-loaded nanoparticles (d-SN38@NPs/iRGD). Upon intravenous injection, d-SN38@NPs with high drug loading efficiency (33.92 ± 1.33%) could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD. The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy. The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm, which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.
ABSTRACT
To study the in situ intestinal absorption kinetics of flrubiprofen in rats, the absorption of flurbiprofen in small intestine (duodenum, jejunum and ileum) and colon of rats was investigated using in situ single-pass perfusion method and the drug content was measured by HPLC. The effects of drug concentration on the intestinal absorption were investigated. The K(a) and P(app) values of flurbiprofen in the small intestine and colon had no significant difference (P > 0.05). Drug concentration (4.0, 10.0 and 16.0 mg x L(-1)) had no significant influence on the K(a) values (P > 0.05). However, when concentration was 4.0 mg x L(-1) and 10.0 mg x L(-1), significant effect on the P(app) values (P 0.05). The K(a) and P(app) values of flurbiprofen on the perfusion flow rate had significant difference (P < 0.05). Flurbiprofen could be absorbed at all segments of the intestine in rats and had no special absorption window. The absorption of flurbiprofen complies with the facilitated diffusion in the general intestinal segments, and accompany with the cytopsistransport mechanism probably. The perfusion flow rate had significant effect on the K(a) and P(app).