Background: Steric stabilization of liposomes using PEGylation has been used widely in pharmaceutical research to overcome the limitations of conventional liposomes and to extend circulation time. PEGylation tended to improve the physicochemical stability and reverse the chemoresistance in multidrug-resistant (MDR) breast cancer cell lines. In this study, PEGylated formulations of disulfiram (DS) and paclitaxel (PAC) were developed using the ethanol-based proliposome technology. Methods: PEGylated liposomal formulations of disulfiram (DS) and paclitaxel (PAC) were developed using the ethanol-based proliposome approach combined with high-pressure homogenization (HPH). The liposomes were characterized for particle size, polydispersity index (PDI), zeta potential, drug loading efficiency (DLE%), and drug entrapment efficiency (DEE%). Cytotoxicity studies were performed on sensitive (MCF7, MDA-MB-231) and chemoresistant (MDA-MB-231_PAC10) breast cancer cell lines using the MTT assay to assess the anti-ancer potential of the formulations. Synergistic cytotoxic effects of DS and PAC co-delivery were also evaluated. Results: There was no significant difference in drug loading (DLE%) and drug entrapment efficiency (EE%) between conventional liposomes and the developed PEGylated vesicles. DS demonstrated higher loading in liposomes than PAC, and a greater cytotoxic effect on both sensitive (MCF7 and MDA-MB-231) and chemoresistant (MDA-MB-231_PAC10) human breast cancer cell lines. For both DS- and PAC-loaded liposomes, PEGylation did not compromise the cytotoxic effect on both sensitive and chemoresistant cells. Interestingly, the combination of DS- and PAC-loaded PEGylated liposomes had significantly higher cytotoxic effect and lower IC50 than that of each drug alone. Conclusions: Overall, PEGylated liposomal formulation of DS and PAC acted synergistically to reverse the multidrug resistance in breast cancer cells and could serve as a promising system for delivery of PAC and DS simultaneously in one formulation using an alcohol-based proliposome formulation.

Background: NAD(P)H quinone dehydrogenase 1 (NQO1), a detoxification enzyme regulated by the Nrf2 cytoprotective pathway, is overexpressed in pancreatic ductal adenocarcinoma (PDAC). NQO1 levels are also influenced by the C609T single-nucleotide polymorphism (SNP). We hypothesized that elevated NQO1 would confer chemoresistance in PDAC and predict poor patient outcome. Methods: NQO1 tumor levels and germline C609T SNP status were assessed in archival samples from the European Study Group for Pancreatic Cancer (ESPAC) trials. NQO1 expression (H-score) was treated as continuous for survival regression analyses and dichotomized for visual summaries. Nrf2 or downstream gene induction was assessed in Nrf2 reporter mice or in PDAC cells following exposure to gemcitabine (Gem), 5-fluorouracil (5-FU), or the capecitabine (Cap) metabolite 5-fluoro-5′-deoxyuridine (5’-DFUR). Colony formation following NQO1 depletion was assessed. Results: NQO1 tumor levels correlated with germline C609T SNP status (P < .001). Contrary to our hypothesis, high NQO1 expression was associated with improved survival in ESPAC-4 patients randomized to GemCap (HR = 0.87 [95% CI = 0.751 to 0.999]; P = .049), and had no association to outcome in the Gem-only treated arm (HR = 0.98 [95% CI = 0.78 to 1.23]; P = .867). Including genotype data did not improve predictive model performance. Neither Gem nor 5-FU induced Nrf2 in vivo. At high concentrations, they suppressed Nrf2/NQO1 in PDAC cells, an effect not mitigated by co-treatment with 5’-DFUR. NQO1 depletion experiments revealed that NQO1 inhibits colony formation. The strongest inhibition was observed when NQO1-positive cells were co-treated with Gem and 5’-DFUR, supporting our clinical data from ESPAC. Conclusion: High tumor NQO1 predicts better outcome following GemCap therapy.

Category: Midfoot/Forefoot; Other Introduction/Purpose: First metatarsophalangeal (MTP) arthrodesis is a common procedure for hallux MTP pathology. In the setting of prior procedures with resultant bone loss, porous titanium wedges provide an alternative to allograft or autograft. The purpose of this study was to report clinical and radiographic outcomes achieved with titanium wedges used in 1st MTP arthrodesis in a revision setting. Methods: A retrospective analysis was performed in 10 patients (mean age 65.8) with prior 1st MTP procedures who underwent 1st MTP arthrodesis with use of porous titanium wedges from February 2014 to March 2020. Outcomes were assessed using both clinical (Visual Analogue Scale, Foot and Ankle Ability Measure, Mental Health Continuum Short Form, 36-Item Short Form Survey, need for revision) and radiographic parameters. Patients were followed from a minimum of 6 months up to 6 years (mean 31.4 months). Results: Average Foot and Ankle Ability Measure (FAAM) score was 91.1 +/- 14.7 (75.1 +/- 5.3 FAAM Activities of Daily Living; 17.9 +/- 9.9 FAAM Sports). Average pain visual analogue scale was 1.9 +/- 1.7. Average Mental Health Continuum-short form score was 34.2 +/- 8.5. Postoperative computed tomography (CT) imaging demonstrated lack of osseous integration in two of six CT scans obtained. Four patients underwent subsequent revision procedures, 3 for hardware prominence and 1 for failure of fusion. Conclusion: To our knowledge, these data represent the first reported clinical and radiographic outcomes in patients undergoing revision 1st MTP arthrodesis with use of porous titanium wedges. Further research should focus on comparative data with other commonly performed operative techniques.

New approaches are urgently needed to enhance the radioiodide (RAI) ablation of aggressive and metastatic thyroid cancer. We recently discovered that valosin-containing protein inhibitors (VCPi) such as clotrimazole and disulfiram transiently block sodium iodide symporter (NIS) proteasomal degradation, hence promoting RAI uptake. However, poor bioavailability diminishes their potential impact in vivo . Following 3D modelling and iterative drug design we appraised 26 novel analogues of clotrimazole, as well as albumin nano-encapsulated copper-diethyldithiocarbamate [Cu(DDC) ₂ -alb] – a stabilised reformulation of a disulfiram metabolite. While several clotrimazole analogues specifically increased RAI uptake, the greatest impact was observed with Cu(DDC) ₂ -alb in thyroid cancer cells as well as human primary thyrocytes from patients with thyroid hyperplasia. NanoBRET assays revealed that Cu(DDC) ₂ enhanced the plasma membrane accumulation of NIS in living cells. In BALB/c mice, both intraperitoneal and intravenous administration of Cu(DDC) ₂ -alb significantly enhanced thyroidal ^99m Tc-uptake. RNA-Seq revealed the surprising observation that Cu(DDC) ₂ -alb induced key thyroid transcription factors. Accordingly, expression of PAX8 and NKX2.1 was upregulated in thyroid glands from drug treated mice, with NIS levels correlating closely to ^99m Tc-uptake. As Cu(DDC) ₂ inhibits the VCP cofactor NPL4, with VCP being critical to the proteostatic processing of NIS protein, we identify a new dual agonist of RAI uptake in vivo , with the potential to directly impact RAI therapy for patients with aggressive thyroid cancer.