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A magnetic nanocomposite of GO-Fe3O4@CuO was fabricated via a simple sonochemical technique and successfully utilized for the ultrasound promoted synthesis of regioselective 1,4-disubstituted mono/bis/tris-1,2,3-triazoles (3a–k). This catalyst could be separated conveniently from the reaction mixture using an external magnet and reused up to eight consecutive runs without noticeable drop in the desired product yield. Other noteworthy features of this green protocol are negligible metal leaching from the support during reaction, high yield in lesser time, aqueous media and good results with gram scale synthesis. Representative compounds were also screened for their cytotoxic activity against PC-12 cell line using standard MTT assay and flow cytometry. Trifluoromethyl group containing triazole derivative (3f) displayed cytotoxic activity (IC50 8.3 µg/mL) comparable to the standard drug cisplatin (IC50 5.8 µg/mL).

The rate and extent of drug release under physiological conditions is a key factor influencing the therapeutic activity of a formulation. Real-time detection of drug release by conventional pharmacokinetics approaches is confounded by low sensitivity, particularly in the case of tissue-targeted novel drug delivery systems, where low concentrations of the drug reach systemic circulation. We present a novel fluorescence turn-on platform for real-time monitoring of drug release from nanoparticles based on reversible fluorescence quenching in fluorescein esters. Fluorescein-conjugated carbon nanotubes (CNTs) were esterified with methotrexate in solution and solid phase, followed by supramolecular functionalization with a chemoenhancer (suramin) or/and a stealth agent (dextran sulfate). Suramin was found to increase the cytotoxicity of methotrexate in A549 cells. On the other hand, dextran sulfate exhibited no effect on cytotoxicity or cellular uptake of CNTs by A549 cells, while a decrease in cellular uptake of CNTs and cytotoxicity of methotrexate was observed in macrophages (RAW 264.7 cells). Similar results were also obtained when CNTs were replaced with graphene. Docking studies revealed that the conjugates are not internalized by folate receptors/transporters. Further, docking and molecular dynamics studies revealed the conjugates do not exhibit affinity toward the methotrexate target, dihydrofolate reductase. Molecular dynamics studies also revealed that distinct features of dextran-CNT and suramin-CNT interactions, characterized by π-π interactions between CNTs and dextran/suramin. Our study provides a simple, cost-effective, and scalable method for the synthesis of nanoparticles conferred with the ability to monitor drug release in real-time. This method could also be extended to other drugs and other types of nanoparticles.

Carbon nanotubes (CNTs) are an emerging drug delivery system, but their success is thwarted by potential toxicity concerns. In vitro and in vivo studies imply toxic potential of CNTs, but their pot...

Polymeric nanoparticles (PNPs) are a promising platform for drug, gene, and vaccine delivery. Although generally regarded as safe, the toxicity of PNPs is not well documented. The present study investigated in vitro toxicity of poly-ε-caprolactone, poly(DL-lactic acid), poly(lactide-cocaprolactone), and poly(lactide-co-glycide) NPs and possible mechanism of toxicity. The concentration-dependent effect of PNPs on cell viability was determined in a macrophage (RAW 264.7), hepatocyte (Hep G2), lung epithelial (A549), kidney epithelial (A498), and neuronal (Neuro 2A) cell lines. PNPs show toxicity at high concentrations in all cell lines. PNPs were efficiently internalized by RAW 264.7 cells and stimulated reactive oxygen species and tumor necrosis factor-alpha production. However, reactive nitrogen species and interleukin-6 production as well as lysosomal and mitochondrial stability remained unaffected. The intracellular degradation of PNPs was determined by monitoring changes in osmolality of culture medium and a novel fluorescence recovery after quenching assay. Cell death showed a good correlation with osmolality of culture medium suggesting the role of increased osmolality in cell death.

Cancer cell-selective, nuclear targeting is expected to enhance the therapeutic efficacy of a myriad of antineoplastic drugs, particularly those whose pharmacodynamic site of action is the nucleus. In this study, a steroid-macromolecular bioconjugate based on PEG-linked 17β-Estradiol (E2) was appended to intrinsically cell-penetrable multiwalled carbon nanotubes (MWCNTs) for intranuclear drug delivery and effective breast cancer treatment, both in vitro and in vivo. Taking Doxorubicin (DOX) as a model anticancer agent, we tried to elucidate how E2 appendage influences the cell internalization, intracellular trafficking, and antitumor efficacy of the supramolecularly complexed drug. We observed that the combination of DOX with E2-PEG-MWCNTs not only facilitated nuclear targeting through an estrogen receptor (ER)-mediated pathway but also deciphered to a synergistic anticancer response in vivo. The antitumor efficacy of DOX@E2-PEG-MWCNTs in chemically breast cancer-induced female rats was approximately 18, 17, 5, and 2 times higher compared to the groups exposed to saline, drug-deprived E2-PEG-MWCNTs, free DOX, and DOX@m-PEG-MWCNTs, respectively. While free DOX treatment induced severe cardiotoxicity in animals, animals treated with DOX@m-PEG-MWCNTs and DOX@E2-PEG-MWCNTs were devoid of any perceivable cardiotoxicity, hepatotoxicity, and nephrotoxicity. To the best of our knowledge, this is the first instance in which cancer cell-selective, intranuclear drug delivery, and, subsequently, effective in vivo breast cancer therapy has been achieved using estrogen-appended MWCNTs as the molecular transporter.

The present study reports the design, synthesis, and biological evaluation of a novel, intravenously injectable, theranostic prodrug based on multiwalled carbon nanotubes (MWCNTs) concomitantly decorated with a fluorochrome (Alexa-fluor, AF488/647), radionucleide (Technitium-99m), tumor-targeting module (folic acid, FA), and anticancer agent (methotrexate, MTX). Specifically, MTX was conjugated to MWCNTs via a serum-stable yet intracellularly hydrolyzable ester linkage to ensure minimum drug loss in circulation. Cell uptake studies corroborated the selective internalization of AF-FA-MTX-MWCNTs (1) by folate receptor (FR) positive human lung (A549) and breast (MCF 7) cancer cells through FR mediated endocytosis. Lysosomal trafficking of 1 enabled the conjugate to exert higher anticancer activity as compared to its nontargeted counterpart that was mainly restricted to cytoplasm. Tumor-specific accumulation of 1 in Ehlrich Ascites Tumor (EAT) xenografted mice was almost 19 and 8.6 times higher than free MTX and FA-deprived MWCNTs. Subsequently, the conjugate 1 was shown to arrest tumor growth more effectively in chemically breast tumor induced rats, when compared to either free MTX or nontargeted controls. Interestingly, the anticancer activities of the ester-linked CNT-MTX conjugates (including the one deprived of FA) were significantly higher than their amide-linked counterpart, suggesting that cleavability of linkers between drug and multifunctional nanotubes critically influence their therapeutic performance. The results were also supported by in silico docking and ligand similarity analysis. Toxicity studies in mice confirmed that all CNT-MTX conjugates were devoid of any perceivable hepatotoxicity, cardiotoxicity, and nephrotoxicity. Overall, the delivery property of MWCNTs, high tumor binding avidity of FA, optical detectability of AF fluorochromes, and radio-traceability of (99m)Tc could be successfully integrated and partitioned on a single CNT-platform to augment the therapeutic efficacy of MTX against FR overexpressing cancer cells while allowing a real-time monitoring of treatment response through multimodal imaging.

A systematic, quantitative study has been conducted to elucidate the effect of oxidation protocol and time on the size, integrity and surface characteristics of multiwalled carbon nanotubes (MWCNTs). Pristine MWCNTs with initial lengths ranging between (i) 2–5 μm and (ii) 1–2 μm were selected for the study. Two oxidation protocols, sonication at 40 °C and reflux at 80 °C in a mixture of concentrated H2SO4 and HNO3 (3:1 v/v) were examined with each variety of MWCNTs. Time dependence of oxidative shortening could be correlated by two empirical, exponential relationships: (i) √L0 − √Lt = k log t (Eq. (1) ) and (ii) Lt/L0 = c × exp (kt) (Eq. (2) ), where L0 and Lt represented the initial and final length of the nanotubes oxidized separately for t hours under ultrasonication and reflux conditions respectively. Time and length dependence of surface carboxyl density was modeled using the following equations: (iii) COOH density (mmol/g, ultrasonication) = 3.088 + [0.353 × t(h)] – [1.185 × Lt (μm)] (Eq. (3) ) (iv) COOH density (mmol/g, reflux) = 2.412 + [0.604 × t(h)] – [0.662 × Lt (μm)] (Eq. (4) ), which suggest that oxidative shortening and carboxyl enrichment of MWCNTs is not only time-dependent but equally influenced by the oxidation protocol.

The present study reports the optimized synthesis, physicochemical characterization, and biological evaluation of a novel, multiwalled carbon nanotube-hyaluronic acid (MWCNT-HA) conjugate, complexed with an anticancer agent, Doxorubicin (DOX) via π-π stacking interaction. The therapeutic conjugate was concomitantly labeled with a near-infrared fluorescent dye, Alexa-Flour-647 (AF-647), and radiotracer Technetium-99m ((99m)Tc) to track its whereabouts both in vitro and in vivo via optical and scintigraphic imaging techniques. Covalent functionalization of MWCNTs with HA facilitated their internalization into human lung adenocarcinoma, A549 cells via hyaluronan receptors (HR) mediated endocytosis. Internalized nanotubes showed lysosomal trafficking, followed by low pH-triggered DOX release under endolysosomal conditions. Consequently, DOX-loaded HA-MWCNTs exhibited 3.2 times higher cytotoxicity and increased apoptotic activity than free DOX in equivalent concentrations. Organ distribution studies in Ehlrich ascites tumor (EAT) bearing mice model indicated that tumor specific localization of (99m)Tc-MWCNT-HA-DOX is significantly higher than both free drug and nontargeted MWCNTs. Pharmacodynamic studies in chemically breast-cancer-induced rats showed that the tumor-growth inhibitory effect of HA-MWCNT-DOX was 5 times higher than free DOX in equivalent concentration. DOX delivered through HA-MWCNTs was devoid of any detectable cardiotoxity, hepatotoxicity, or nephrotoxicity. All these promising attributes make HA-MWCNTs a "smart" platform for tumor-targeted delivery of anticancer agents.

The present study investigates the effect of functionalization density on the toxicity and cellular uptake of oxidized multiwalled carbon nanotubes (f-MWCNTs) in vitro. The toxicity of f-MWCNTs at varying degrees of carboxylation was assessed in a murine macrophage RAW 264.7 cell line, a model for liver Kupffer cells. In vitro cytotoxicity of oxidized MWCNTs was directly proportional to their functionalization density. The increased cytotoxicity was associated with a concurrent increase in the number of apoptotic cells and production of reactive nitrogen species (RNS). In contrast, reactive oxygen species (ROS) generation was the highest in the case of pristine MWCNTs and decreased with increased functionalization density. Quantitative cellular uptake studies indicated that endogenous ROS production was independent of the concentration of CNTs internalized by a specific cell population and was directly proportional to their surface hydrophobicity. Mechanistic studies suggested that cellular uptake of CNTs was critically charge-dependent and mediated through scavenger receptors, albeit the involvement of nonscavenger receptor mechanisms at low CNT concentrations and their saturation at the experimental concentration cannot be ruled out. A mathematical model was established to correlate between the cellular uptake of CNTs with their length and zeta potential. In an attempt to correlate the results of in vitro toxicity experiments with those of the in vivo toxicity in the mouse model, we found that the toxicity trends in vitro and in vivo are rather opposing. The apparent anomaly was explained on the basis of different experimental conditions and doses associated with cells under in vivo and in vitro culture conditions.

The present investigation consists in the development and characterization of CoQ10 loaded PLGA nanoparticles (CoQ10-NPs, size

The present investigation reports an extensive evaluation of in vitro and in vivo anticancer efficacy of orally administered doxorubicin-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Dox-NPs) in a breast cancer induced animal model. Spherically shaped Dox-NPs were prepared with an entrapment efficiency and particle size of 55.40 ± 2.30% and 160.20 ± 0.99 nm, respectively, and freeze-dried with 5% trehalose using stepwise freeze-drying. Cytotoxicity, as investigated on C127I cell line, revealed insignificant differences between the IC(50) of free Dox and Dox-NPs treated cells in the first 24 h, while higher cytotoxicity was demonstrated by Dox-NPs, following 72 h of incubation. Confocal laser scanning microscopy (CLSM) imaging corroborated that nanoparticles were efficiently localized into the nuclear region of C127I cells. The cellular uptake profile of Dox-NPs revealed both time and concentration dependent increases in the Caco-2 cell uptake as compared to the free Dox solution. Further, Dox-NPs significantly suppressed the growth of breast tumor in female Sprague-Dawley (SD) rats upon oral administration. Finally, orally administered Dox-NPs showed a marked reduction in cardiotoxicity when compared with intravenously injected free Dox as also evident by the increased level of malondialdehyde (MDA), lactate dehydrogenase (LDH), and creatine phosphokinase (CK-MB) and reduced levels of glutathione (GSH) and superoxide dismutase (SOD). The reduced cardiotoxicity of orally administered Dox-NPs was also confirmed by the major histopathological changes in the heart tissue after the treatments of intravenously injected free Dox and orally delivered Dox-NPs.

Presently available methods for determining antimicrobial activity include broth dilution and disc diffusion. However, these methods can not be employed for study of vapor phase antimicrobial activity. The present study describes a new method and a new apparatus for determination of vapor phase antimicrobial activity of volatile substances against bacteria. The method can be used for assessing effect of new and existing compounds on environmental microflora.

Livistona chinensis is used in traditional Chinese medicine as an anticancer agent. Experimental studies have shown the antiproliferative and antiangiogenic properties of extracts of L. chinensis fruits and seeds. In the present study, qualitative phytochemical composition of L. chinensis fruits was investigated. We hypothesized that the presence of high concentration of phenolic compounds with astringent properties may result in bacterial cell death. Hence, antibacterial activity of an aqueous extract of L. chinensis fruits was investigated against Staphylococcus aureus. The antibacterial activity was attributed to DNA, enzyme and protein denaturing properties of the phenolic compounds present in the extract. The extract also resulted in increased membrane permeability. The antibacterial, DNA and enzyme denaturing and membrane damaging activity was limited to an acid-precipitable fraction of the extract and these effects were abrogated in presence of proteins. The membrane damaging activity of phenolic compounds was also observed in leucocytes. In conclusion, this study reported the antibacterial activity of the fruits of L. chinensis due to their high content of phenolic compounds.

Different types of nanomaterials possess excellent physical and chemical properties. Nanoparticles (NPs) have been implicated for use in drug and gene delivery. Several in vitro and in vivo studies suggest the cytotoxic and proinflammatory potential of NPs. Further, parenteral administration of NPs results in their accumulation in several tissues. The possible mechanism of toxicity appears to be production of free radicals, mitogen activated protein kinase (MAPK) activation and translocation of transcription factors from cytoplasm to nucleus. This leads to induction of apoptosis, growth arrest, and cell death. Further, factors like nuclear factor-κB (NF-κB) lead to production of proinflammatory cytokines. The present review focuses on the cytotoxicity, biodistribution, and mechanism of NPs toxicity with special emphasis on carbon nanotubes (CNTs) toxicity.

Silver nanoparticles (Ag NPs) are used in consumer products and wound dressings due to their antimicrobial properties. However, in addition to toxic effects on microbes, Ag NPs can also induce stress responses as well as cytotoxicity in mammalian cells. We observed that Ag NPs are efficiently internalized via scavenger receptor-mediated phagocytosis in murine macrophages. Confocal and electron microscopy analysis revealed that internalized Ag NPs localize in the cytoplasm. Ag NPs cause mitochondrial damage, induce apoptosis and cell death. These effects were abrogated in presence of Ag ion-reactive, thiol-containing compounds suggesting the central of Ag ions in Ag NP toxicity. Quantitative image analysis revealed that intracellular dissolution of Ag NPs occurs about 50 times faster than in water. In conclusion, we demonstrate for the first time that Ag NPs are internalized by scavenger receptors, trafficked to cytoplasm and induce toxicity by releasing Ag ions.

The immunomodulatory effects of opioids are known in various infections. However, little is known about the effects of opioids in tuberculosis (TB). In the present study, we report the effects of morphine in Mycobacterium smegmatis infection in mice and macrophages. Morphine exerted a dose-dependent suppression of infection in vivo: 50 and 100 mg/kg morphine exerted significant (P

The present work demonstrates a novel strategy to synthesize orthogonally bio-engineered magnetonanohybrids (MNPs) through the design of versatile, biocompatible linkers whose structure includes: (i) a robust anchor to bind with metal-oxide surfaces; (ii) tailored surface groups to act as spacers and (iii) a general method to implement orthogonal functionalizations of the substrate via “click chemistry”. Ligands that possess the synthetic generality of features (i)–(iii) are categorized as “universal ligands”. Herein, we report the synthesis of a novel, azido-terminated poly(ethylene glycol) (PEG) silane that can easily self-assemble on MNPs through hetero-condensation between surface hydroxyl groups and the silane end of the ligand, and simultaneously provide multiple clickable sites for high density, chemoselective bio-conjugation. To establish the universal-ligand-strategy, we clicked alkyl-functionalized folate onto the surface of PEGylated MNPs. By further integrating a near-infrared fluorescent (NIRF) marker (Alexa-Fluor 647) with MNPs, we demonstrated their folate-receptor mediated internalization inside cancer cells and subsequent translocation into lysosomes and mitochondria. Ex vivo NIRF imaging established that the azido-PEG-silane developed in course of the study can effectively reduce the sequestration of MNPs by macrophage organs (viz. liver and spleen). These folate–PEG-MNPs were not only stealth and noncytotoxic but their dual optical and magnetic properties aided in tracking their whereabouts through combined magnetic resonance and optical imaging. Together, these results provided a strong motivation for the future use of the “universal ligand” strategy towards development of “smart” nanohybrids for theragnostic applications.