Repurposing Quinacrine for Treatment of Malignant Mesothelioma: In-Vitro Therapeutic and Mechanistic Evaluation

Malignant mesothelioma (MM) is a rare type of cancer primarily affecting mesothelial cells lining the pleural cavity. In this study, we propose to repurpose quinacrine (QA), a widely approved anti-malarial drug, for Malignant Pleural Mesothelioma (MPM) treatment. QA demonstrates high degree of cytotoxicity against both immortalized and primary patient-derived cell lines with sub-micromolar 50% inhibitory concentration (IC50) values ranging from 1.2 µM (H2452) to 5.03 µM (H28). Further, QA also inhibited cellular migration and colony formation in MPM cells, demonstrated using scratch and clonogenic assays, respectively. A 3D-spheroid cell culture experiment was performed to mimic in-vivo tumor conditions, and QA was reported to be highly effective in this simulated cellular model. Anti-angiogenic properties were also discovered for QA. Autophagy inhibition assay was performed, and results revealed that QA successfully inhibited autophagy process in MPM cells, which has been cited to be one of the survival pathways for MPM. Annexin V real-time apoptosis study revealed significant apoptotic induction in MPM cells following QA treatment. Western blots confirmed inhibition of autophagy and induction of apoptosis. These studies highlight anti-mesothelioma efficacy of QA at low doses, which can be instrumental in developing it as a stand-alone treatment strategy for MPM

Development and characterization of site specific target sensitive liposomes for the delivery of thrombolytic agents

In recent times, search for potent and highly selective thrombolytic agents with minimal side effects has become a major area of research. The aim of the present study was to develop and characterize target sensitive (TS) liposomes encapsulating streptokinase, a thrombolytic agent. The developed TS liposomes were composed of dioleylphophatidyl ethanolamine (DOPE) and dipalmityl-c(RGDfK) (10:1 mol/mol). Dipalmityl-c(RGDfK) was synthesized using typical carbodiimide chemistry using palmitic acid and c(RGDfK), while lysine was used as a spacer. Liposomes were of 100–120 nm size. In vitro drug release study showed that nearly 40% drug of the entrapped drug was released in 12 h in the PBS (pH 7.4), however on incubation with activated platelet about 90% of drug was released within 45 min. The results suggested target sensitivity of the liposomes. Further, targeting potential was confirmed using fluorescent microscopy and flow cytometry. Clot lysis study revealed that TS liposomes could not only reduce the clot lysis time but also increase the extent of clot lysis as compared to non-liposomal streptokinase solution. In conclusion, the present liposomal formulation will target the thrombolytic agent to the activated platelets in the thrombus and hence will improve the therapeutic efficacy of the drug

Development and characterization of highly selective target-sensitive liposomes for the delivery of streptokinase: in vitro/in vivo studies

Streptokinase is one of the most commonly used thrombolytic agents for the treatment of thromboembolism. Short half-life of the streptokinase requires administration of higher dose which results in various side effects including systemic haemorrhage due to activation of systemic plasmin. To increase the selectivity of the streptokinase and hence to reduce side effects, various novel carriers have been developed. Among these carriers, liposomes have been emerged as versatile carrier. In the present study, highly selective target-sensitive liposomes were developed and evaluated by in vitro and in vivo studies. Prepared liposomes were found to release streptokinase in vitro following binding with activated platelets. Intravital microscopy studies in thrombosed murine model revealed higher accumulation of liposomes in the thrombus area. In vivo thrombolysis study was performed in the human clot inoculated rat model. Results of the study showed that target-sensitive liposomes dissolved 28.27 ± 1.56% thrombus as compared to 17.18 ± 1.23% of non-liposomal streptokinase. Further, it was also observed that target-sensitive liposomes reduced the clot dissolution time as compared to streptokinase solution. Studies concluded that developed liposomes might be pragmatic carriers for the treatment of thromboembolism

Brain Delivery of a Potent Opioid Receptor Agonist, Biphalin during Ischemic Stroke: Role of Organic Anion Transporting Polypeptide (OATP)

Transporters (expressed) at the blood-brain barrier (BBB) can play an essential role in the treatment of brain injury by transporting neuroprotective substance to the central nervous system. The goal of this study was to understand the role of organic anion transporting polypeptide (OATP1; OATP1A2 in humans and oatp1a4 in rodents) in the transport of a potent opioid receptor agonist, biphalin, across the BBB during ischemic stroke. Brain microvascular endothelial cells (BMECs) that were differentiated from human induced pluripotent stem cells (iPSCs) were used in the present study. The effect of oxygen-glucose deprivation (OGD) and reperfusion on the OATP1 expression, uptake, and transport of biphalin was measured in induced pluripotent stem cells differentiated brain microvascular endothelial cells (iPSC–BMECs) in the presence and absence of an OATP1 substrate, estrone-3-sulfate (E3S). Biphalin brain permeability was quantified while using a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. It was found that iPSC-BMECs expressed OATP1. In vitro studies showed that biphalin BBB uptake and transport decreased in the presence of an OATP1 specific substrate. It was also observed that OGD and reperfusion modulate the expression and function of OATP1 in BMECs. This study strongly demonstrates that OATP1 contributes to the transport of biphalin across the BBB and increased expression of OATP1 during OGD-reperfusion could provide a novel target for improving ischemic brain drug delivery of biphalin or other potential neurotherapeutics that have affinity to this BBB transporter.Blood-Brain Barrier Research Center; Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center School of Pharmacy, Amarillo, TXOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]