Assessment of Irinotecan Loading and Releasing Profiles of a Novel Drug-Eluting Microsphere (CalliSpheres) In Vitro.

Background: This study investigated irinotecan loading efficiency and release profiles of CalliSpheres in vitro. Materials and Methods: CalliSpheres with size of 50-150, 100-300, and 300-500 µm and irinotecan at different amounts (20, 40, 80, and 100 mg) and concentrations (5 and 10 mg/mL) were prepared for experiments. Dynamic light scattering and Agilent 1260 high-performance liquid chromatography system were used to quantify bead diameters and the efficiency of irinotecan loading and releasing properties, respectively. Results: The diameters of CalliSpheres with all sizes were reduced after being loaded with irinotecan compared with unloaded ones with shrinkage rate ranging from 8.5% to 16.2%. Above 80% irinotecan was incorporated with CalliSpheres with all sizes when being loaded with irinotecan 20, 40, and 80 mg, while loading efficiencies were 70%-80% when being loaded with irinotecan 100 mg. Besides, elevated loading efficiency was observed at a higher concentration of irinotecan solutions (10 mg/mL) compared with a lower concentration (5 mg/mL) for CalliSpheres with all sizes. As to release profiles, irinotecan was released from CalliSpheres very quickly, and irinotecan release rate was elevated in CalliSpheres with smaller size than CalliSpheres with larger size within the first 12 h, whereas it was similar among CalliSpheres with different sizes at 24 and 48 h with maximum release rate ∼100%. In addition, fetal bovine serum seemed to have an effect on the accelerating irinotecan release. Conclusion: CalliSpheres exhibits good physical characteristics, satisfied irinotecan loading efficiency, and acceptable releasing profiles.

Biocompatibility of a New Kind of Polyvinyl Alcohol Embolic Microspheres: In Vitro and In Vivo Evaluation.

The aim of this study is to investigate the biocompatibility of polyvinyl alcohol (PVA) embolic microspheres by in vivo and in vitro evaluations. Two specifications of PVA microspheres including colorless microspheres (1 g microspheres with 7 mL 0.9% sodium chloride (SC) per vial, size: 500-700 µm) and blue microspheres (2 g microspheres with 7 mL 0.9% SC per vial, size: 500-700 µm) were assessed for biocompatibility. The vitro cytotoxicity was evaluated in L929 cells by MTT assay. Acute systemic toxicity and 28-repeat dose intravenous subchronic toxicity were assessed in 20 ICR mice and 40 SD rates, respectively. Skin sensitization was conducted in 30 adult albino guinea pigs by maximization test, in addition, intracutaneous reaction test was performed in New Zealand white rabbits. Hemolysis ratio of PVA microspheres was evaluated with rabbit blood. Moreover, test for genotoxicity was assessed by bacterial reverse mutation test and mouse lymphoma mutagenesis assay. No cytotoxicity, hemolysis, or acute toxicity of PVA microspheres was found, and slight fluctuations of biochemical indexes were observed in test of 28-day repeat dose intravenous subchronic toxicity, while these changes remained within our historical permitted range. Maximization test and intracutaneous reactivity test disclosed no irritation to skin or tissues. According to bacterial reverse mutation test and mouse lymphoma mutagenesis assay, no genotoxicity of PVA microspheres was observed. PVA microspheres showed excellent biocompatibility both in vivo and in vitro, and they were promising embolic materials for drug-eluting beads transarterial chemoembolization (DEB-TACE) therapy.

Coexisted components of Salvia miltiorrhiza enhance intestinal absorption of cryptotanshinone via inhibition of the intestinal P-gp.

Cryptotanshinone, derived from the roots of Salvia miltiorrhiza Bge and Salvia przewalskii Maxim, is the major active component and possesses significant antibacterial, antidermatophytic, antioxidant, anti-inflammatory and anticancer activities. The objective of this study was to investigate the intestinal absorptive characteristics of cryptotanshinone as well as the absorptive behavior influenced by co-administration of the diterpenoid tanshinones and danxingfang using an in vitro everted rat gut sac model. The results showed a good linear correlation between cryptotanshinone of absorption and the incubation time from 10 to 70min. The concentration dependence showed that a non-linear correlation existed between the cryptotanshinone absorption and the concentration at 100 µg/ml. Coexisting diterpenoid tanshinones and danxingfang could significantly enhance the absorption of cryptotanshinone. Coexisting diterpenoid tanshinones and danxingfang, which influenced cryptotanshinone's absorption, manifested as similar to that of the P-glycoprotein inhibitor. The underlying mechanism of the improvement of oral bioavailability was proposed that coexisting diterpenoid tanshinones and danxingfang could decrease the efflux transport of cryptotanshinone by P-glycoprotein.

Structural elucidation of metabolites of tanshinone I and its analogue dihydrotanshinone I in rats by HPLC-ESI-MSn.

Tanshinone I and its analogue dihydrotanshinone I are the major active components isolated from Salvia miltiorrhiza Bunge and Salvia Przewalskii Maxim. These compounds have been found to possess significant antibacterial, anti-dermatophytic, antioxidant, anti-inflammatory and anticancer activities. Fifteen phase I metabolites and two phase II metabolites of tanshinone I and dihydrotanshinone I in rat bile were elucidated and identified by a sensitive HPLC-ESI-MS(n) method. The molecular structures of the metabolites are presented on the basis of the characteristics of their precursor ions, product ions and chromatographic retention times. The results indicate that the phase I metabolites are biotransformed through four main pathways: dehydrogenation, hydroxylation, furan ring cleavage and oxidation metabolism. Phase II metabolites were mainly identified as the sulfated conjugates which showed a characteristic neutral loss of 80 Da. The biotransformed pathways of tanshinone I and dihydrotanshinone I were proposed on the basis of the investigation.

Structural elucidation of in vitro and in vivo metabolites of cryptotanshinone by HPLC-DAD-ESI-MS(n).

The structural elucidation of the in vivo and in vitro metabolites of cryptotanshinone which was the major active component isolated from rhizome of Salvia miltiorrhiza Bunge and possessed significant antibacterial, anti-dermatophytic, antioxidant, anti-inflammatory and anticancer activities was described. Nineteen phase I metabolites and six phase II metabolites of cryptotanshinone were elucidated and identified by a sensitive LC-DAD-ESI-MS(n) method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, chromatographic retention time and ultraviolet spectra. The in vivo and in vitro phase I metabolites were mainly biotransformed by four main routes, which were dehydrogenation, hydroxylation, furan ring cleavage and oxidation metabolism, and among these phase I reactions, dehydrogenation was the predominant metabolic pathway. Six in vivo phase II metabolites were identified as the glucuronided and the sulfated conjugates which showed a neutral loss of 176 and 80 Da, respectively. The biotransformation pathways of cryptotanshinone were proposed on the basis of this research.