Drug repurposing-based nanoplatform via modulating autophagy to enhance chemo-phototherapy against colorectal cancer.

Multi-modal combination therapy is regarded as a promising approach to cancer treatment. Combining chemotherapy and phototherapy is an essential multi-modal combination therapy endeavor. Ivermectin (IVM) is a potent antiparasitic agent identified as having potential antitumor properties. However, the fact that it induces protective autophagy while killing tumor cells poses a challenge to its further application. IR780 iodide (IR780) is a near-infrared (NIR) dye with outstanding photothermal therapy (PTT) and photodynamic therapy (PDT) effects. However, the hydrophobicity, instability, and low tumor uptake of IR780 limit its clinical applications. Here, we have structurally modified IR780 with hydroxychloroquine, an autophagy inhibitor, to synthesize a novel compound H780. H780 and IVM can form H780-IVM nanoparticles (H-I NPs) via self-assembly. Using hyaluronic acid (HA) to modify the H-I NPs, a novel nano-delivery system HA/H780-IVM nanoparticles (HA/H-I NPs) was synthesized for chemotherapy-phototherapy of colorectal cancer (CRC). Under NIR laser irradiation, HA/H-I NPs effectively overcame the limitations of IR780 and IVM and exhibited potent cytotoxicity. In vitro and in vivo experiment results showed that HA/H-I NPs exhibited excellent anti-CRC effects. Therefore, our study provides a novel strategy for CRC treatment that could enhance chemo-phototherapy by modulating autophagy.

In vitro ion channel profile and ex vivo cardiac electrophysiology properties of the R(-) and S(+) enantiomers of hydroxychloroquine.

Hydroxychloroquine (HCQ) is a derivative of the antimalaria drug chloroquine primarily prescribed for autoimmune diseases. Recent attempts to repurpose HCQ in the treatment of corona virus disease 2019 has raised concerns because of its propensity to prolong the QT-segment on the electrocardiogram, an effect associated with increased pro-arrhythmic risk. Since chirality can affect drug pharmacological properties, we have evaluated the functional effects of the R(-) and S(+) enantiomers of HCQ on six ion channels contributing to the cardiac action potential and on electrophysiological parameters of isolated Purkinje fibers. We found that R(-)HCQ and S(+)HCQ block human Kir2.1 and hERG potassium channels in the 1 µM-100 µM range with a 2-4 fold enantiomeric separation. NaV1.5 sodium currents and CaV1.2 calcium currents, as well as KV4.3 and KV7.1 potassium currents remained unaffected at up to 90 µM. In rabbit Purkinje fibers, R(-)HCQ prominently depolarized the membrane resting potential, inducing autogenic activity at 10 µM and 30 µM, while S(+)HCQ primarily increased the action potential duration, inducing occasional early afterdepolarization at these concentrations. These data suggest that both enantiomers of HCQ can alter cardiac tissue electrophysiology at concentrations above their plasmatic levels at therapeutic doses, and that chirality does not substantially influence their arrhythmogenic potential in vitro.

Novel drug delivery of dual acting prodrugs of hydroxychloroquine with aryl acetic acid NSAIDs: Design, kinetics and pharmacological study.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by restricted movements of joints of hand, feet, elbow, knees and neck but principally the synovial joints. Though etiopathology is not exactly known, treatment paradigms are evolving to provide a tighter control over symptoms and disease progression. Current trend is introduction of disease modifying anti-rheumatoid drugs (DMARDs) at early stages. Hydroxychloroquine (HCQ) and nonsteroidal anti-inflammatory drugs (NSAIDs) are two mechanistically different categories widely used in the management of RA where the first arrests the disease progression while the latter offers symptomatic relief. Present work aims at minimizing problems of slow onset and accumulation of HCQ in non-targeted sites and local gastric intolerance to NSAIDs by designing their mutual ester prodrugs. Synthesis of prodrugs was achieved by CDI coupling and structures were confirmed by IR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analysis. Prodrugs resisted hydrolysis in acidic environment of the stomach but exhibited significant release in small intestine. Upon oral administration of prodrugs to rats, 40.5-49% HCQ and 53.4-66.8% of NSAIDs were recovered in 8.5-10 h in blood. Urine and feces samples pooled over a period of 24 h exhibited 2.3-3.5% and 0.75-0.9% of HCQ, respectively, without any presence of intact prodrugs or NSAIDs. Prodrugs were pharmacologically evaluated for analgesic and anti-inflammatory activities using standard animal models. Among all, prodrugs of HCQ with licofelone (HL) and aceclofenac (HA) produced superior analgesia, improved weight gain, normalization of joint diameter/paw volume than HCQ and physical mixtures of HCQ and NSAIDs. Hematological and biochemical studies indicated significant step up in RBC, Hb, platelet count, total protein nutrient (TPN) levels and step down in WBC, serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) by the treatment with HL and HA. Through these novel codrugs, problems of slow onset and accumulation of HCQ in non-targeted sites and local gastric intolerance to NSAIDs were well addressed. These dual acting mutual prodrugs of two mechanistically different anti-arthritic agents could be explored further as promising strategy for effective management of RA.

Viewing dynamic interactions of proteins and a model lipid membrane with atomic force microscopy.

The information covered in this chapter will present a model homogenous membrane preparation technique and dynamic imaging procedure that can be successfully applied to more than one type of lipid study and atomic force microscope (AFM) instrument setup. The basic procedural steps have been used with an Asylum Research MFP-3D BIO and the Bruker (formerly, Veeco) BioScope. The AFM imaging protocol has been supplemented by procedures (not to be presented in this chapter) of ellipsometry, standardized western blotting, and dot-blots to verify appropriate purity and activity of all experimental molecular components; excellent purity and activity level of the lipids, proteins, and drug(s) greatly influence the success of imaging experiments in the scanning probe microscopy field. The major goal of the chapter is to provide detailed procedures for sample preparation and operation of the Asylum Research MFP-3D BIO AFM. In addition, one should be cognizant that our comprehensive description in the use of the MFP-3D BIO's functions for successful image acquisitions and analyses is greatly enhanced by Asylum Research's (AR's) accompanying extensive manual(s), technical notes, and AR's users forum. Ultimately, the stepwise protocol and information will allow novice personnel to begin acquiring quality images for processing and analysis with minimal supervision.