This paper is to study the inhibitory effect of water soluble polymers--methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC-M), poloxamer (F68) and polyvidon (PVP) on osthole (OST) crystallization and investigate the impact of polymer concentration and viscosity on crystallization behavior. Also, UV spectrophotometry method was used to determine the drug concentration at different time point to draw the OST concentration-time curve. Results show that HPMC has the most significant inhibition effect on OST crystallization, and drug concentration level is 1.61 times higher than that in control solution within 8 h followed by PVP (1.54) and MC (1.45) respectively. The kinetics of OST recrystallization can be described using first-order reaction, and the crystallization rate constants obtained by analyzing the regression equation indicate that HPMC-60SH-4000 and HPMC-60SH-10000 can greatly influence OST crystal formation. The dissolution rate of drugs precipitated from water-soluble polymer solutions is faster compared with controls in pH 1.2 HCl and pH 6.8 phosphate buffers, which demonstrated that water-soluble polymers can not only change the behavior of drug crystallization but markedly improve the dissolution rate of water insoluble drugs.

Objective:To preliminarily estimate and study the effect of nucleic acid testing in blood screening on the residual risk (RR) of transfusion transmitted HBV infection (TTI HBV).Methods:Using the NAT yield/WP ratio model and adopting the relevant data of information management system of practice comparison working party in the Mainland of China, this paper analyzed the trend of the RR of TTI HBV among 18 blood centers from 2015 to 2019 in China, and compared the impact of two kinds of blood screening strategies which were ELISA+ ID-NAT/MP-NAT (individual-donation nucleic acid testing or mini-pool nucleic acid testing) and ELISA + MP-NAT on RR in 2019.Results:The overall trends of the 5-year RR of HBV among 18 blood centers showed by trend chi square test were NAT single positive rate trend χ2= 39.42( P<0.01) and residual risk trend χ2= 279.792( P<0.01); The influence on RR from the differences of ELISA+ ID-NAT/MP-NAT and ELISA+ MP-NAT was statistically significant, and chi square test showed that χ2= 7.4( P<0.01). Conclusions:Since the implementation of nucleic acid testing in the blood screening in China from 2015, the residual risk of transfusion transmitted HBV infection has decreased year by year. The observed two blood screening strategies which dominated in China may lead to discrepancy in the residual risk of TTI.

Metastasis and resistance are main causes to affect the outcome of the current anticancer therapies. Heat shock protein 90 (Hsp90) as an ATP-dependent molecular chaperone takes important role in the tumor metastasis and resistance. Targeting Hsp90 and downregulating its expression show promising in inhibiting tumor metastasis and resistance. In this study, a redox-responsive dual-drug nanocarrier was constructed for the effective delivery of a commonly used chemotherapeutic drug PTX, and a COA-modified 4-arm PEG polymer (4PSC) was synthesized. COA, an active component in oleanolic acid that exerts strong antitumor activity by downregulating Hsp90 expression, was used as a structural and functional element to endow 4PSC with redox responsiveness and Hsp90 inhibitory activity. Our results showed that 4PSC/PTX nanomicelles efficiently delivered PTX and COA to tumor locations without inducing systemic toxicity. By blocking the Hsp90 signaling pathway, 4PSC significantly enhanced the antitumor effect of PTX, inhibiting tumor proliferation and invasiveness as well as chemotherapy-induced resistance in vitro. Remarkable results were further confirmed in vivo with two preclinical tumor models. These findings demonstrate that the COA-modified 4PSC drug delivery nanosystem provides a potential platform for enhancing the efficacy of chemotherapies.