Rapidly separating dissolving microneedles with sustained-release colchicine and stabilized uricase for simplified long-term gout management

Despite growing prevalence and incidence, the management of gout remains suboptimal. The intermittent nature of the gout makes the long-term urate-lowering therapy (ULT) particularly important for gout management. However, patients are reluctant to take medication day after day to manage incurable occasional gout flares, and suffer from possible long-term toxicity. Therefore, a safe and easy-to-operate drug delivery system with simple preparation for the long-term management of gout is very necessary. Here, a chitosan-containing sustained-release microneedle system co-loaded with colchicine and uricase liposomes were fabricated to achieve this goal. This microneedle system was confirmed to successfully deliver the drug to the skin and maintain a one-week drug retention. Furthermore, its powerful therapeutic potency to manage gout was investigated in both acute gouty and chronic gouty models. Besides, the drug co-delivery system could help avoid long-term daily oral colchicine, a drug with a narrow therapeutic index. This system also avoids mass injection of uricase by improving its stability, enhancing the clinical application value of uricase. In general, this two-drug system reduces the dosage of uricase and colchicine and improves the patient's compliance, which has a strong clinical translation.

Disulfide stabilization reveals conserved dynamic features between SARS-CoV-1 and SARS-CoV-2 spikes.

SARS-CoV-2 spike protein (S) is structurally dynamic and has been observed by cryo-EM to adopt a variety of prefusion conformations that can be categorized as locked, closed and open. The locked conformations feature tightly packed trimers with structural elements incompatible with RBD in "up" position. For SARS-CoV-2 S, it has been shown that the locked conformations are transient under neutral pH. Probably due to their transience, locked conformations remain largely uncharacterized for SARS-CoV-1 S. Intriguingly, locked conformations were the only conformations captured for S proteins of bat and pangolin origin SARS-related coronaviruses. In this study, we introduced x1, x2, and x3 disulfides into SARS-CoV-1 S. Some of these disulfides have been shown to preserve rare locked conformations when introduced to SARS-CoV-2 S. Introduction of these disulfides allowed us to image a variety of locked and other rare conformations for SARS-CoV-1 S by cryo-EM. We identified bound cofactors and structural features that are associated with SARS-CoV-1 S locked conformations. We compare newly determined structures to other available spike structures of Sarbecoviruses to identify conserved features and discuss their possible functions.

D ifferent cytotoxic effects of hydroxycamptothecin on human lung cancer cells and human embryo lung fibroblast cells / 中国药理学与毒理学杂志

OBJECTIVE Toinvestigatethedifferenceofcytotoxiceffectsofhydroxycamptothecin(HCPT)onhuman lungcancercelsA549andhumanembryolungfibroblastcelsMRC-5.METHODS A549celsandMRC-5celswere treated with HCPT 20-200 μmol·L-1 for 24,48 and 72 h,or pulse treated with HCPT 50-400 μmol·L-1 for 24 h along with 5 d release.cellsurvival was detected by MTT assay.Morphological changes for both types of cells were observed under an inverted phase-contrast microscope.cellcycle and apoptosis in both cells treated with HCPT 50 μmol·L-1 for 48 h weredeterminedbyflowcytometry.RESULTS HCPT20-200μmol·L-1inhibitedthesurvivalofbothcelsinaconcen-tration-dependent manner and more cytotoxicity was observed in A549 cells for 48 h.The concentration-effect correlation coefficient(r)of HCPT in A549 and MRC-5 cells for 48 h was 0.898 (P=0.015)and 0.996 (P=2.56E-5)respectively. The inhibition rates were significantly different between A549 and MRC-5 cells with treatment of HCPT 20,50,80,1 00, 1 60 and 200 μmol·L-1 for 48 h (P<0.05).The IC50 of HCPT on A549 and MRC-5 cells was (24.00 ±0.69)μmol·L-1 and (1 23.63 ±3.89)μmol·L-1 respectively,indicating that A549 cells were 5-fold more sensitive to HCPT than MRC-5 cells at 48 h.After exposure to HCPT 50 μmol·L-1 for 48 h,some A549 cells were rounded up and shrank dramatical y, and some cells underwent membrane blebbing or lysing while MRC-5 cells had no obvious changes.cellcycle and apop-tosis analysis showed that A549 cells were arrested at both S and G2/M phases and apoptosis occurred but MRC-5 cells were just arrested at S phase.In the recovery growth curve,the growth of A549 cells was inhibited to a larger extent than MRC-5 cells and the growth retardation stil existed for 24 h in both cells.The survival of MRC-5 cells was faster than that ofA549cels,althoughtherewasnocompleterecoveryineithercel.CONCLUSION A549celsaremoresensitiveto HCPT than MRC-5 cells due to the fact that HCPT induces cellcycle arrest at both S and G2/M phases and apoptosis in A549 cells,but only triggers S phase arrest in the MRC-5 cells.