CD44 mediated colon cancer targeting mutlifaceted lignin nanoparticles: Synthesis, in vitro characterization and in vivo efficacy studies.

Hyaluronic acid (HA) coated irinotecan loaded lignin nanoparticles (HDLNPs) were synthesized using ionic interaction method. Optimized nanoparticles were characterized for their active chemotherapeutic targeting potential to CD44 receptors overly-expressed on cancer cells. Blood component interaction studies supported hemocompatible nature of HDLNPs and also demonstrated their sustained plasma residence property. Cell anti-proliferation and mitochondrial depolarization studies on HT-29 cells suggest significantly (p < 0.01) improved chemotherapeutic efficacy of HDLNPs. In vitro cell based studies showed that nanoparticles have retained antioxidant activity of lignin that can prevent cancer relapse. In vivo biodistribution studies in tumor-bearing Balb/c mice confirmed improved drug localization in tumor site for longer duration. Tumor regression and histopathological studies indicated the efficacy ofligand-assisted targeting chemotherapy over the conventional therapy. Hematological and biochemical estimation suggested that irinotecan-associated myelosuppression, liver steatosis and rare kidney failure can be avoided by its encapsulation in HA-coated lignin nanoparticles. HDLNPs were found to be stable over a period of 12 months.

Base-mediated ynone-isocyanide [3+2] cycloaddition: a general method to 2,3,4-tri-substituted 1-H-pyrroles and bis-pyrroles.

A transition-metal-free and base-promoted one-pot synthesis of 2,3,4-trisubstituted 1-H-pyrroles has been developed. The reaction occurs through the [3+2] cycloaddition of differently functionalized ynones and isocyanides. The reaction's advantageous features are operational simplicity, atom economy, and functional group tolerance with broad substrate scope. In addition, 1,3-bis-pyrrole formation and gram-scale synthesis were also achieved. Furthermore, the synthetic utility of the products was also investigated via isocyanide insertion and pyrrole-triazole hybrid formation in good yield.

2-Alkynylarylnitrile: An Emerging Precursor for the Generation of Carbo- and Heterocycles.

In the pursuit of a coherent synthetic route for the synthesis of carbo- and heterocycles, 2-alkynylarylnitrile has been recognized as a useful and versatile building block in organic synthesis due to the dual capacity of this precursor to act with a nucleophilic of electrophilic nature. The alkynes implanted at the ortho position improved the reactivity of the substrate for tandem cyclization and annulations, which led to the synthesis of diverse and complex cyclic compounds. This mini review summarizes the literature on the synthetic transformations of 2-alkynylarylnitrile into biologically relevant heterocycles as well as carbocycles such as isoindoles, isoquinolines, naphthalenes, and indenones as well as building blocks for the synthesis of various natural products. We hope that this concise review will be a promissory entry for future research in this area.

BF3-Etherate-catalyzed tandem reaction of 2-formylarylketones with electron-rich arenes/heteroarenes: an assembly of isobenzofurans.

An efficient and BF3·Et2O-catalyzed chemoselective synthesis of diversified 1,3-diarylisobenzofuran in a high yield has been described. The reaction proceeds through sequential hydroarylation-cyclization between 2-formylarylketones and electron-rich arenes/heteroarenes. Advantageous features of the developed methodology include operational simplicity, a broad substrate scope, and applicability towards gram scale synthesis. The utility of isobenzofuran derivatives as the diene was extended to the synthesis of [4+2] cyclo-adducts with DMAD and the synthesis of 1,2-dicarbonylarenes in good yields.

Assessing the potential of lignin nanoparticles as drug carrier: Synthesis, cytotoxicity and genotoxicity studies.

Lignin nanoparticles synthesis is among recent developments in lignin valorization especially for biomedical applications. In this study, a new technique where complete self-assembling of lignin was ensured by simultaneous solvent displacement and flash pH change was used to optimize particle size of blank lignin nanoparticles (BLNPs) for suitability in cell uptake along with maximized yield. To establish BLNPs as drug carrier, safety studies including hemocompatibility, cytotoxicity and elaborate genotoxicity studies on Drosophila melanogaster as a model organism were done. Finally, irinotecan loaded lignin nanoparticles (DLNPs) were synthesized to establish their drug carrying potential and thorough in vitro characterization was performed. BLNPs with controllable size (⁓152 nm), low polydispersity (<0.2), maximized yield (>65%), negative surface charge (-22 to -23 mV), spherical shape and smooth surface were obtained with acceptable %hemolysis (<2%). In vitro cytotoxicity studies revealed that BLNPs were significantly toxic (74.38 ± 4.74%) in human breast adenocarcinoma (MCF-7), slightly toxic (38.8 ± 4.70%) in human alveolar epithelial adenocarcinoma (A-549) and insignificantly toxic (15.89 ± 2.84%) to human embryonic kidney (HEK-293) cells. BLNPs showed concentration dependent early neuronal defects in Drosophila, but nuclei fragmentation and gut cell damage were absent. Sustained release DLNPs with high drug loading reduced the IC50 value of irinotecan by almost 3 folds.

Structure, Genome, Infection Cycle and Clinical Manifestations Associated with Human Papillomavirus.

A small, non-enveloped, obligatory parasite, Human papillomavirus (HPV) is known to be the cause of a range of malignancies. These entail benign infections like genital warts as well as malignant, life-threatening conditions such as cervical cancer. Since a very high mortality rate is associated with HPV caused cancers (cervical cancer is a 2nd leading cause of death caused due to cancer among women globally), there is an escalating need to understand and search for ways to combat such medical conditions. Under the same light, the given article provides an insight into the world of this versatile pathogen. Distinct aspects related to HPV have been discussed here. Emphasis has been laid upon the composition, function and assembly of capsid proteins (structural studies) and various genetic elements and their gene products (genomic studies). The essence of the mechanism behind the development of persistent infection and modes responsible for the transmission of the infectious particles has been briefly covered. Finally, the review outlines various infections and diseases caused by HPV with a major focus on their clinical and histological manifestations.

Mechanistic insights of Cu(ii)-mediated ortho-C-H amination of arenes by capturing fleeting intermediates and theoretical calculations.

The capture of reactive intermediates empowers chemists to conjecture the detail of a chemical transformation. Here we explore the mechanism of a C-H amination by intercepting short-lived intermediates in real time using online mass spectrometry. Computational study unravels the favorable pathway of the proposed dual mechanism of the reaction.

Harnessing the reactivity of ortho-formyl-arylketones: base-promoted regiospecific synthesis of functionalized isoquinolines.

An efficient and base-mediated one-pot regiospecific synthesis of structurally diversified isoquinolines and benzo[h] isoquinolines from easily accessible ortho-formyl-arylketones and aryl/(het)arylmethanamines has been described. Challenging 3-alkynyl/alkenyl isoquinolines and bis-isoquinolines were easily attained through this developed chemistry, which can be further used for various organic transformations. Operational simplicity, high atom-economy, broad substrate scope, functional group tolerance and applicability towards large scale synthesis are the advantageous features of this developed methodology.

Metal-Free Carbonyl-Assisted Regioselective Hydration of Alkynes: An Access to Dicarbonyls.

Metal-free regioselective hydration of o-alkynylaldehydes with the assistance of neighboring carbonyl oxygen is disclosed. The developed protocol provides a facile route to synthesize a series of multisubstituted carbonyl containing scaffolds that enable the potential application toward the synthesis of highly diversified 5-azaindoles. γ-Carbolines and 2,8-diazacarbazoles can also be accessed directly without isolating the dicarbonyl compounds. The developed methodology is operationally simple and environment-friendly, tolerates a wide variety of functional groups, and is applicable toward large scale synthesis.

Cu(II)-Mediated Ortho-C-H Amination of Arenes with Free Amines.

Copper-mediated direct ortho-C-H amination of arenes has been accomplished with the aid of easily removable bidentate pyridine N-oxide as a directing group. The use of free cyclic secondary amines and anilines as aminating agents and inexpensive copper acetate makes the strategy more effective and favorable from the economic point of view. This reaction is compatible with a wide range of functional groups to synthesize a variety of amine-containing products of high interest. This method also allows the short synthesis of the central scaffold of pharmaceutically relevant Staphylococcus aureus Sortase A inhibitors.

Base-Mediated Direct Transformation of N-Propargylamines into 2,3,5-Trisubstituted 1 H-Pyrroles.

An efficient and base-mediated intramolecular cyclization of N-propargylamines for the synthesis of structurally diversified pyrroles in high yield has been described. The developed methodology is broadly applicable and is tolerated by a variety of functional groups. Key intermediates of natural product discoipyrrole C as well as HMG-CoA-reductase inhibitor have been successfully synthesized using developed chemistry. The proposed mechanism was supported by control experiments.

Melanoma treatment: from conventional to nanotechnology.

INTRODUCTION: Melanoma is the most serious form of skin cancer causing most of the skin cancer-related deaths. The incidence of melanoma has risen so dramatically over past few years that no other solid or blood malignancy comes close to it in terms of increased incidence. The main problem associated with the treatment of melanoma is low response rate to the existing treatment modalities, which in turn is due to the incomplete response by chemotherapeutic agents and inherent resistance of melanoma cells. MATERIALS AND METHODS: Conventional therapeutic strategies, as well as, recent literature on melanoma have been thoroughly studied. This review summarizes the base of anti-melanoma treatment with conventional chemotherapeutic drugs, followed by an account of recent studies which explored the potential of nanotechnology and newer strategies and agents in melanoma treatment. CONCLUSION: Although melanoma is curable if detected in its early localized form, metastatic melanoma continues to be a therapeutic challenge. Metastatic melanoma has a very poor prognosis and conventional therapies have not improved the outcomes of the treatment so far. For this reason, newer combinations of anti-melanoma drugs and newer strategies utilizing nanotechnology have been constantly explored.

Transition-Metal-Free Access to Pyridocarbazoles from 2-Alkynylindole-3-carbaldehydes via Azomethine Ylide.

An efficient approach for the synthesis of functionalized tetrahydro-pyrido/quinolinocarbazoles from 2-alkynylindole-3-carbaldehydes and l-proline utilizing a metal-free decarboxylative cyclization, ring expansion, and ring contraction strategy via the generation of azomethine ylide was developed. The reaction of 2-alkynylindole-3-carbaldehydes with l-thioproline leads to the formation of γ-carbolines. By virtue of this expedient method, a diverse range of biologically active heteroannulated carbazoles can be synthesized efficiently.

Zinc oxide nanoparticles: a promising nanomaterial for biomedical applications.

Zinc oxide (ZnO) nanoparticles (NPs) are a promising platform for use in biomedical research, especially given their anticancer and antimicrobial activities. These activities are associated with the ability of ZnO NPs to generate reactive oxygen species (ROS) and induce apoptosis. In addition, ZnO NPs have been successfully exploited as drug carriers for loading and transporting drugs to target sites, thereby reducing unwanted toxicity and off-target effects, and resulting in amplified synergistic effects. Here, we discuss the synthesis and biomedical applications of ZnO NPs.

Development and characterization of metal oxide nanoparticles for the delivery of anticancer drug.

The aim of the study was to prepare chemotherapeutic agent-loaded zinc oxide nanoparticles for the intracellular delivery of drug, for better therapeutic activity. Zinc oxide nanoparticles have inherent anticancer properties, hence it was envisaged that by loading the anticancer drug into zinc oxide nanoparticles, enhanced anticancer activity might be observed. Zinc oxide nanoparticles were prepared using zinc nitrate and sodium hydroxide. Starch was used as the stabilizing agent. The nanoparticles prepared were characterized for size, shape, entrapment efficiency, and drug release. Further, cell line studies were performed to evaluate cellular uptake and cytotoxicity profile using MCF-7 cells. A hemolysis study was performed to check the acute toxicity of the nanoparticles. The nanoparticles were found to be 476.4 ± 2.51 nm in size, with low PDI (0.312 ± 0.02) and high entrapment efficiency (> 85%). The nanoparticles were stable, and did not form aggregates on storage in the dispersed form. A cytotoxicity study demonstrated that drug-loaded zinc oxide nanoparticles exhibited higher anticancer activity as compared to either blank zinc oxide nanoparticles and doxorubicin (DOX) alone, or their mixture. A hemolytic test revealed that the prepared zinc oxide nanoparticles caused negligible hemolysis. Thus, it can be concluded that zinc oxide nanoparticles loaded with DOX resulted in better uptake of the chemotherapeutic agent, and at the same time, showed low toxicity towards normal cells.

Metal nanoparticles: a theranostic nanotool against cancer.

Cancer remains one of the most deadly diseases worldwide, but conventional anticancer therapies come with several drawbacks. Therefore, there is a need to develop new anticancer strategies. Theranostics is a strategy that combines treatment with diagnosis and monitoring. Metal nanoparticles are proposed as one of the most promising theranostic agents for the treatment of cancer. Thus, metals including iron, gold (Au), silver (Ag), zinc (Zn), and titanium, have potential as anticancer agents, either inherently or as a result of surface modifications. As a functional component of theranostic tools, metal nanoparticles have crucial dual roles as a diagnostic and active therapeutic agent for the treatment of cancer.