Polymeric micelles of a copolymer composed of all-trans retinoic acid, methoxy-poly(ethylene glycol), and b-poly(N-(2 hydroxypropyl) methacrylamide) as a doxorubicin-delivery platform and for combination chemotherapy in breast cancer.

Delivery of combination chemotherapeutic agents to the tumor via nanovesicles has the potential for superior tumor suppression and reduced toxicity. Herein, we prepare a block copolymer (mPH-RA) composed of methoxy-poly(ethylene glycol) (mPEG), b-poly(N-(2 hydroxypropyl) methacrylamide) (pHPMA), and all-trans retinoic acid (ATRA) by conjugating ATRA to the pre-formed copolymer, mPEG-b-pHPMA(mP-b-pH). Doxorubicin-loaded micelles, Dox@mP-b-pH, and Dox@mPH-RA were characterized by determining particle size, zeta potential, % DL, EE, Dox release, hemolysis study, and by DSC. The Dox@mPH-RA micelles (mPH-RA: Dox ratios of 10:0.5-2) displayed nano-size (36-45 nm), EE. 26-74%, and DL. 2.9-5.6%. Dox@mPH-RA micelles displayed the highest penetrability and cytotoxicity than free Dox and Dox@mP-b-pH micelles in breast cancer cell lines. Dox@mPH-RA exhibited the highest induction of apoptosis (94.1 ± 3%) than Dox (52.1 ± 4.5%), and Dox@mP-b-pH (81.7 ± 3%), and arrested cells in the highest population in G2 and S phase. Dox@mPH-RA increased the t1/2 and Cmax of Dox and demonstrated improved therapeutic efficacy and highest Dox distribution to the tumor. The Dox@mPH-RA increased the levels of apoptosis markers, caspase 3, 7, Ki-67, and caused the highest DNA fragmentation. The presence of RA improved the micelles' physicochemical properties, Dox-loading ability, and the therapeutic potential in Dox@mPH-RA via the combination therapeutic strategy.

PEGylated N-(2 hydroxypropyl) methacrylamide polymeric micelles as nanocarriers for the delivery of doxorubicin in breast cancer.

In the present study, polymeric micelles constituted of N-(2-hydroxypropyl)methacrylamide (HPMA) and methoxypoly(ethylene glycol) (mPEG)-based copolymer, mPEG-b-HPMA was studied for the delivery of an anticancer drug, doxorubicin (DOX) by physically loading the drug into its core. A series of mPEG-b-HPMA copolymers of different molecular weights (MWs, ∼4000-25,000 Da) by using various initiator: monomer feed ratios (1:25/75/125/175) were synthesized by radical polymerization technique. The DOX-loaded micelles were prepared at different drug to polymer ratios by thin film hydration method. Block copolymers were structurally characterized by gel permeation chromatography (GPC), 1H-NMR spectroscopy, fourier transform infrared spectroscopy (FTIR), and critical micelles concentration studies. The DLS and SEM studies indicated that the micelles were spherical with diameters ∼20-100 nm. The DOX-loaded mPEG-b-HPMA micelles, P6-M1, prepared by the polymer synthesized using initiator: monomer feed ratios of 1:175 and at polymer to drug ratios of 10:1 exhibited low particle sizes (∼46.8 nm), highest drug loading and encapsulation efficiencies (5.6 %, and 63.3 %, respectively) compared to the other tested formulations. Confocal microscopy study indicated that the P6-M1 was taken up by breast cancer cell lines, 4T1, MCF-7, and MDA-MB-231in a time-dependent manner. P6-M1 displayed lower half maximal inhibitory concentration (IC50) compared to free drug in all tested treatment durations compared to free DOX. P6-M1 was safe in hemolysis studies with sustained DOX residence in circulation compared to free DOX. The results indicated that mPEG-b-HPMA could be utilized to load DOX effectively, and the optimized nano-micelles, P6-M1 could serve as a promising nanomedicine to treat breast cancer.

PT3: A Novel Benzamide Class Histone Deacetylase 3 Inhibitor Improves Learning and Memory in Novel Object Recognition Mouse Model.

The importance of HDAC3 in transcriptional regulation of genes associated with long-term memory is well established. Here, we report a novel HDAC3 inhibitor, PT3, with an excellent blood-brain barrier permeability and ability to enhance long-term memory in mouse model of novel object recognition (NOR). PT3 exhibited higher selectivity for HDAC3 over HDAC1, HDAC6, and HDAC8 compared to the reference compound CI994. PT3 has significant distribution into the brain tissue with Cmax at 0.5 h and t1/2 of 2.5 h. Treatment with PT3 significantly improved the discrimination index in C57/BL6 mice in the NOR model. Brain tissue analysis of mice treated with PT3 for NOR test showed significant increase in H3K9 acetylation in hippocampus. Gene expression analysis by RT-qPCR of the hippocampus tissue revealed upregulation of CREB 1, BDNF, TRKB, Nr4a2, c-fos, PKA, GAP 43, PSD 95 and MMP9 expression in mice treated with PT3. Similar to the phenotype observed in the in vivo experiment, we found upregulation of H3K9 acetylation, CREB 1, BDNF, TRKB, Nr4a2, c-fos, PKA, GAP 43 and MMP9 expression in mouse neuronal (N2A) cells treated with PT3. Thus, our preclinical studies identify PT3 as a potential HDAC3 selective inhibitor that crosses the blood-brain barrier and improves the long-term memory formation in C57/BL6 mice. We propose PT3 as a candidate with therapeutic potential to treat age-related memory loss as well as other disorders with declined memory function like Alzheimer's disease.

Targeted Bioimaging of Cancer Cells Using Free Folic Acid-Sensitive Molybdenum Disulfide Quantum Dots through Fluorescence "Turn-Off".

In the present study, a proficient way for targeted bioimaging of folate receptor (FR)-positive cancer cells using free folic acid (FA)- and MoS2 QD-based nanoprobes is discussed along with its advantages over the preparation of orthodox direct FA-nanoprobe bioconjugates for the imaging. The water-soluble MoS2 QDs of size 4-5 nm with cysteine functionalization are synthesized by a simplistic bottom-up hydrothermal method. The as-prepared MoS2 QDs exhibit the blue emission with the highest emission intensity at 444 nm upon excitation of 370 nm. The MoS2 QDs are too sensitive toward FA to produce an effective and stable nanofiber structure through supramolecular interaction, which demonstrates ∼97% quenching of fluorescence. Moreover, the high selectivity and sensitivity of MoS2 QDs toward FA make the MoS2 QD-based nanoprobe an appropriate candidate for FA-targeted "turn-off" imaging probes for in vivo study of FA-pretreated FR-overexpressed cancer cells. It is obvious from the confocal microscopy images that the FA-pretreated B16F10 cancer cells show higher population of dimmed fluorescence compared to untreated cancer cells and HEK-293 normal cells. The flow cytometry study quantitatively reveals the significant difference of the geometric mean of fluorescence between FA-pretreated and untreated B16F10 cancer cells. Hence, these MoS2 QD-based nanoprobes can be applied as potential nanoprobes for the prediagnosis of cancer through targeted bioimaging.

Synergistic co-loading of vincristine improved chemotherapeutic potential of pegylated liposomal doxorubicin against triple negative breast cancer and non-small cell lung cancer.

The current work aims to explore the biological characteristics of vincristine synergistic co-loading into pegylated liposomal doxorubicin in non-indicated modalities of non-small cell lung cancer (NSCLC) and triple negative breast cancer (TNBC). The combinatorial liposome prepared by active co-loading of the drugs against modified ammonium ion gradient exhibited 95% encapsulation of both drugs. The cellular uptake studies using confocal microscopy and flow cytometry showed significantly increased uptake of dual drug formulation as against liposomal doxorubicin. The co-loaded liposome formulation had significantly increased cell cycle arrest in G2/M phase with subsequent apoptosis and reduced cell viability in both tumor cell lines than doxorubicin liposome. This carrier exhibited similar acute toxicity, pharmacokinetic and tissue distribution profiles with significant increase in tumor regression as compared to liposomal doxorubicin. These results indicate that co-encapsulation of vincristine into clinically used pegylated liposomal doxorubicin significantly improved in-vitro and in-vivo therapeutic efficacy against NSCLC and TNBC.

Albumin-based lipoprotein nanoparticles for improved delivery and anticancer activity of curcumin for cancer treatment.

Aim: To prepare curcumin (CUR)-loaded, dioleoyl phosphoethanolamine-conjugated human serum albumin nanoparticles (NPs) and to evaluate their effectiveness in breast cancer therapy. Materials & methods: The CUR-loaded NPs were physicochemically characterized and evaluated for their cytotoxicity in murine (4T1) and human breast cancer (MDA-MB-231) cell lines. The antitumor efficacy of the nanomedicine was evaluated in 4T1 tumor bearing mice. Results: The prepared NPs exhibited encapsulation and drug loading efficiencies of approximately 79 and 21%, respectively. The NPs were taken up efficiently and markedly hindered the proliferation of breast cancer cells compared with free drug. NPs exhibited greater suppression of tumor growth in 4T1 tumor bearing mice. Conclusion: CUR-human serum albumin-dioleoyl phosphoethanolamine NPs could be a potential treatment alternative for solid tumors, including breast cancer.

Design, synthesis, biological evaluation and molecular docking study of arylcarboxamido piperidine and piperazine-based hydroxamates as potential HDAC8 inhibitors with promising anticancer activity.

HDAC8 has been established as one of the vital targets as far as the cancer is concerned. Different compounds having potential HDAC inhibitory activity have been approved by USFDA. However, none of these compounds are selective towards specific HDAC isoform. In this current study, some new hydroxamate derivatives with alkylpiperidine and alkylpiperazine linker moieties have been designed, synthesized and biologically evaluated. All these compounds are effective HDAC8 inhibitors comprising more or less similar cytotoxic potential against different cancer cell lines. It is observed that the piperazine scaffold containing compound is more active than the compound with piperidine scaffold for exerting HDAC8 inhibitory activity. Moreover, the 4-quinolyl cap group is better than the biphenyl group which is better than the benzyl group for producing higher HDAC8 inhibition as well as cytotoxicity. These compounds displayed selective HDAC8 inhibition over HDAC3. Moreover, these compounds showed an increased caspase3/7 activity suggesting their anticancer potential through modulation of apoptotic pathways. Molecular docking study with three potent compounds was performed with both HDAC3 and HDAC8 enzymes to understand the selectivity profile of these compounds. Compound containing 4-quinolyl cap group with alkyl piperazinyl urea linker moiety has been emerged out as the lead molecule that may be further modified to design more effective and selective HDAC8 inhibitors in future.

Design, synthesis and biological evaluation of 2-(3,4-dimethoxyphenyl)-6 (1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-a]pyridine analogues as antiproliferative agents.

Two series of forty five novel 2-(3,4-dimethoxyphenyl)-6-(1,2,3,6-tetrahydropyridin-4-yl) imidazo[1,2-a]pyridine analogues (IPA 1-22, IPS 1-22 and IP-NH) have been designed, synthesized and structures confirmed by 1H NMR, 13C NMR, mass spectrometry. Furthermore, single crystal was developed for IPS-13. All the final derived conjugates were evaluated for their in vitro antiproliferative activity against a panel of diverse cancer cell lines viz., A549 (lung cancer), HeLa (cervical cancer), B16F10 (melanoma) and found to show potent anticancer activity on the tested cell lines. Many of them showed the IC50 values in the range 2.0-20.0 µM. The most active compounds (IPA 5,6,8,9,12,16,17,19 and IPS 7,8,9,22) from IPA and IPS series were screened to determine their cytotoxicity on HEK-293 (human embryonic kidney) normal cell line and were found to be nontoxic to normal human cells. The molecular interactions of the derivatised conjugates were also supported by molecular docking simulations. These derivatives may serve as lead structures for development of novel potential anticancer drug candidates.

Design, synthesis and anti-tumour activity of new pyrimidine-pyrrole appended triazoles.

The new pyrimidine-pyrrole scaffolds (7a-7m) with substituted 1,2,3-traizole moiety were synthesized in good to mild yields and subjected for anti-cancer activity against melanoma and breast cancer cell lines using MTT assay. The compounds 7f and 7m exhibited highest anti-cancer activity against both the tested cell lines in in vitro assay. The molecular docking analysis provided the insights of binding orientation of pyrimidine-pyrrole nucleus of current ligands and their crucial interactions with Cys797 and other residues of the EGFR tyrosine kinase active site. The interactions of triazole and its various substituted groups with EGFR tyrosine kinase have been discussed.

Probing the photo- and electro-catalytic degradation mechanism of methylene blue dye over ZIF-derived ZnO.

Due to the severe water pollution from effluent dyes, the need of the hour is to find a suitable dye degradation technology, and appropriate catalyst materials. Semiconducting ZnO was produced by pyrolysis of ZIF-8 template. The materials were well characterized with in situ and ex situ XRD and TGA, FE-SEM, HRTEM, UV-DRS, PL, and FRET. The results showed that upon calcination the body centered cubic ZIF-8 produces hexagonal primitive ZnO while retaining the truncated cubic shaped particles. The materials were screened for photo- and electro-catalytic oxidation of methylene blue. In both the different degradation technologies, ZnO synthesized from ZIF-8 outperformed the ZIF-8. The FRET dynamics showed significant spectral overlap of ZnO emission and the methylene blue absorption. It was found to be responsible for the better photocatalytic efficacy of ZnO samples than ZIF-8. The proposed reaction mechanism showed that the surface-bound reactive oxygen species produced either by light exposure or due to applied bias is key to dye degradation. The cytotoxicity of the untreated and ZnO and ZIF-8 treated dye over melanoma cells was evaluated, and it was found that the cytotoxicity of the degraded dye from ZIF-derived ZnO was less compared to that of ZIF-8 treated one.

Enhancement of the aqueous solubility and permeability of a poorly water soluble drug ritonavir via lyophilized milk-based solid dispersions.

In the present study, a lyophilized milk-based solid dispersion (SD) of ritonavir (RTV) was developed with the goal of improving its aqueous solubility. The SD was prepared by lyophilization, and characterized for its physicochemical and functional properties. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), photomicroscopy and powder X-ray diffraction (PXRD) were used to confirm the formation and robustness of the SD formulation. The prepared SD formulations were functionally evaluated by saturation solubility, in vitro drug release and ex vivo permeation studies. The optimized SD formulation exhibited a significantly higher (30-fold) aqueous solubility (11.36 ± 0.06 µg/mL), compared to the pure RTV (0.37 ± 0.03 µg/mL). The in vitro dissolution studies revealed a significantly higher (∼10-fold) efficiency of the optimized SD formulation in releasing the RTV, compared to the pure RTV. The ex vivo permeation studies with the everted intestine method showed that prepared SD formulation significantly improved the permeation of RTV (75.6 ± 3.09, % w/w), compared to pure RTV (20.45 ± 1.68, % w/w). Thus, SD formulation utilizing lyophilized milk as a carrier appears to be a promising alternative strategy to improve the aqueous solubility of poorly water soluble drugs.

The role of phospholipid as a solubility- and permeability-enhancing excipient for the improved delivery of the bioactive phytoconstituents of Bacopa monnieri.

In an attempt to improve the solubility and permeability of Standardized Bacopa Extract (SBE), a complexation approach based on phospholipid was employed. A solvent evaporation method was used to prepare the SBE-phospholipid complex (Bacopa Naturosome, BN). The formulation and process variables were optimized using a central-composite design. The formation of BN was confirmed by photomicroscopy, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Powder X-ray Diffraction (PXRD). The saturation solubility, the in-vitro dissolution, and the ex-vivo permeability studies were used for the functional evaluation of the prepared complex. BN exhibited a significantly higher aqueous solubility compared to the pure SBE (20-fold), or the physical mixture of SBE and the phospholipid (13-fold). Similarly, the in-vitro dissolution revealed a significantly higher efficiency of the prepared complex (BN) in releasing the SBE (>97%) in comparison to the pure SCE (~42%), or the physical mixture (~47%). The ex-vivo permeation studies showed that the prepared BN significantly improved the permeation of SBE (>90%), compared to the pure SBE (~21%), or the physical mixture (~24%). Drug-phospholipid complexation may thus be a promising strategy for solubility enhancement of bioactive phytoconstituents.