Molecular insights and novel approaches for targeting tumor metastasis

Natural-product-based, carrier-free, noncovalent nanoparticles for tumor chemo-photodynamic combination therapy

Cancer, with its diversity, heterogeneity, and complexity, is a significant contributor to global morbidity, disability, and mortality, highlighting the necessity for transformative treatment approaches. Photodynamic therapy (PDT) has aroused continuous interest as a viable alternative to conventional cancer treatments that encounter drug resistance. Nanotechnology has brought new advances in medicine and has shown great potential in drug delivery and cancer treatment. For precise and efficient therapeutic utilization of such a tumor therapeutic approach with high spatiotemporal selectivity and minimal invasiveness, the carrier-free noncovalent nanoparticles (NPs) based on chemo-photodynamic combination therapy is essential. Utilizing natural products as the foundation for nanodrug development offers unparalleled advantages, including exceptional pharmacological activity, easy functionalization/modification, and well biocompatibility. The natural-product-based, carrier-free, noncovalent NPs revealed excellent synergistic anticancer activity in comparison with free photosensitizers and free bioactive natural products, representing an alternative and favorable combination therapeutic avenue to improve therapeutic efficacy. Herein, a comprehensive summary of current strategies and representative application examples of carrier-free noncovalent NPs in the past decade based on natural products (such as paclitaxel, 10-hydroxycamptothecin, doxorubicin, etoposide, combretastatin A4, epigallocatechin gallate, and curcumin) for tumor chemo-photodynamic combination therapy. We highlight the insightful design and synthesis of the smart carrier-free NPs that aim to enhance PDT efficacy. Meanwhile, we discuss the future challenges and potential opportunities associated with these NPs to provide new enlightenment, spur innovative ideas, and facilitate PDT-mediated clinical transformation.

Therapeutic Implications of Dietary Polyphenols-Loaded Nanoemulsions in Cancer Therapy

Cancer is one of the major causes of death worldwide, even the second foremost cause related to non-communicable diseases. Cancer cells typically possess several cellular and biological processes including, persistence, propagation, differentiation, cellular death, and expression of cellular-type specific functions. The molecular picture of carcinogenesis and progression is unwinding, and it appears to be a tangled combination of processes occurring within and between cancer cells and their surrounding tissue matrix. Polyphenols are plant secondary metabolites abundant in fruits, vegetables, cereals, and other natural plant sources. Natural polyphenols have implicated potential anticancer activity by various mechanisms involved in their antitumor action, including modulation of signaling pathways majorly related to cellular proliferation, differentiation, relocation, angiogenesis, metastatic processes, and cell death. The applications of polyphenols have been limited due to the hydrophobic nature and lower oral bioavailability that could be possibly overcome through encapsulating them into nanocarrier-mediated delivery systems, leading to improved anticancer activity. Nanoemulsions (NEs) possess diverse feasible properties, including greater surface area, modifiable surficial charge, higher half-life, site-specific targeting, and formulation imaging capability necessary to create a practical therapeutic impact, and have drawn increased attention in cancer therapy research. This review has summarized and discussed the basic concepts, classification, delivery approaches, and anticancer mechanism of various polyphenols and polyphenols-encapsulated nanoemulsions with improved cancer therapy.

Restoration of Antibacterial Activity of Inactive Antibiotics via Combined Treatment with AgNPs

Antimicrobial resistance poses a huge threat to human health around the world and calls for novel treatments. Combined formulations of NPs and antibiotics have emerged as a viable nanoplatform for combating bacterial resistance. The present research work was performed to investigate the effect of combined formulations of AgNPs with streptomycin, cefaclor, ciprofloxacin, and trimethoprim against multidrug-resistant (MDR) isolates of Staphylococcus aureus and Klebsiella pneumoniae. AgNPs have been synthesized by using the Nigella sativa seed extract, and their characteristics were analyzed. AgNPs depicted concentration-dependent antibacterial effects, as the highest concentration of AgNPs showed the strongest antibacterial activity. Interestingly, AgNPs in conjugation with antibiotics showed an enhanced antibacterial potential against both S. aureus and K. pneumoniae, which suggested synergism between the AgNPs and antibiotics. Against S. aureus, streptomycin and trimethoprim in conjugation with AgNPs presented a synergistic effect, while cefaclor and ciprofloxacin in combination with AgNPs showed an additive effect. However, all of the tested antibiotics depicted a synergistic effect against K. pneumoniae. The lowest value of MIC (0.78 μg/mL) was shown by AgNPs-Stp against S. aureus, whereas AgNPs-Tmp showed the lowest value of MIC (1.56 μg/mL) against K. pneumoniae. The most important point of the present study is that both organisms (S. aureus and K. pneumoniae) showed resistance to antibiotics but turned out to be highly susceptible when the same antibiotic was used in combination with AgNPs. These findings highlight the potential of nanoconjugates (the AgNPs-antibiotic complex) to mitigate the present-day crisis of antibiotic resistance and to combat antimicrobial infections efficiently.

The Chimera of TPGS and Nanoscale Lipid Carriers as Lymphatic Drug Delivery Vehicles to Fight Metastatic Cancers

The lymphatic system (LS) plays a crucial role in fluid balance, transportation of macromolecules, and immune response. Moreover, LS is a channel for microbial invasion and cancer metastasis. Particularly, solid tumors, including lung, breast, melanoma, and prostate cancers, are metastasized across highways of LS. Subsequently, the fabrication of chimeric lymphatic drug delivery systems (LDDS) is a promising strategy to fight cancer metastasis and control microbial pandemics. In this regard, LDDS, in terms of PEG-nanoscaled lipid carriers, elicited a revolution during the COVID-19 pandemic as cargoes for mRNA vaccines. The drug delivered by the lymphatic pathway escapes first-pass metabolism and enhances the drug's bioavailability. Ample approaches, including synthesis of prodrugs, trigging of chylomicron biosynthesis, and fabrication of nanocarriers, facilitate lymphatic drug delivery. Specifically, nanoscales lipid cargoes have the propensity to lymphatic trafficking. Interestingly, TPGSengineered nanoscale lipid cargoes enhance lymphatic trafficking, increase tissue permeation, and, specifically, uptake. Moreover, they overcome biological barriers, control biodistribution, and enhance organelles localization. Most anticancer agents are non-specific, have low bioavailability, and induced drug resistance. Therefore, TPGS-engineered nanoscale lipid chimeras improve the therapeutic impact of anticancer agents. This review highlights lymphatic cancer metastasis, nanoscales lipid cargoes as LDDS, and their influence on lymphatic trafficking, besides the methods of LDD studies.

Piperlongumine Induces Apoptosis and Cytoprotective Autophagy via the MAPK Signaling Pathway in Human Oral Cancer Cells

Oral cancer is a malignant tumor that primarily affects areas such as the lips, tongue, buccal mucosa, salivary gland, and gingiva and has a very high malignancy. Piperlongumine (PL), isolated from long pepper (Piper longum L.), is a natural alkaloid with pharmacological effects, such as anti-inflammatory and anti-atherosclerotic effects. The effect and mechanism of PL in oral cancer cell lines has not been explored. Therefore, this study aimed to investigate the mechanism of anticancer effects of PL in the human oral cancer cell lines MC-3 and HSC-4 in vitro. This study demonstrated that PL inhibits cell proliferation by inducing apoptosis and autophagy in human oral cancer cell lines, which was confirmed by the levels of apoptosis- and autophagy-related proteins through Western blotting. Moreover, the pharmacological blockade of autophagy activation by hydroxychloroquine (HCQ), an autophagy inhibitor, significantly improved PL-induced apoptosis in MC-3 cells, suggesting a cytoprotective effect. In addition, activation of the mitogen-activated protein kinase (MAPK) signaling pathway contributed to PL-induced apoptosis. Collectively, the study suggested that combining an autophagy inhibitor with PL treatment can exert effective anticancer properties in oral cancer cells by inducing apoptosis and cytoprotective autophagy via the JNK-mediated MAPK pathway.

Tailoring Heat Transfer and Bactericidal Response in Multifunctional Cotton Composites

Through the execution of scientific innovations, "smart materials" are shaping the future of technology by interacting and responding to changes in our environment. To make this a successful reality, proper component selection, synthesis procedures, and functional active agents must converge in practical and resource-efficient procedures to lay the foundations for a profitable and sustainable industry. Here we show how the reaction time, temperature, and surface stabilizer concentration impact the most promising functional properties in a cotton-based fabric coated with silver nanoparticles (AgNPs@cotton), i.e., the thermal and bactericidal response. The coating quality was characterized and linked to the selected synthesis parameters and correlated by a parallel description of "proof of concept" experiments for the differential heat transfer (conversion and dissipation properties) and the bactericidal response tested against reference bacteria and natural bacterial populations (from a beach, cenote, and swamp of the Yucatan Peninsula). The quantification of functional responses allowed us to establish the relationship between (i) the size and shape of the AgNPs, (ii) the collective response of their agglomerates, and (iii) the thermal barrier role of a surface modifier as PVP. The procedures and evaluations in this work enable a spectrum of synthesis coordinates that facilitate the formulation of application-modulated fabrics, with grounded examples reflected in "smart packaging", "smart clothing", and "smart dressing".

Molecular insights and therapeutic implications of nanoengineered dietary polyphenols for targeting lung carcinoma: part I

Lung cancer is the second leading cause of cancer-related mortality globally, and non-small-cell lung cancer accounts for most lung cancer cases. Nanotechnology-based drug-delivery systems have exhibited immense potential in lung cancer therapy due to their fascinating physicochemical characteristics, in vivo stability, bioavailability, prolonged and targeted delivery, gastrointestinal absorption and therapeutic efficiency of their numerous chemotherapeutic agents. However, traditional chemotherapeutics have systemic toxicity issues; therefore, dietary polyphenols might potentially replace them in lung cancer treatment. Polyphenol-based targeted nanotherapeutics have demonstrated interaction with a multitude of protein targets and cellular signaling pathways that affect major cellular processes. This review summarizes the various molecular mechanisms and targeted therapeutic potentials of nanoengineered dietary polyphenols in the effective management of lung cancer.

Polyester nanomedicines targeting inflammatory signaling pathways for cancer therapy

The growth of cancerous cells and their responses towards substantial therapeutics are primarily controlled by inflammations (acute and chronic) and inflammation-associated products, which either endorse or repress tumor progression. Additionally, major signaling pathways, including NF-κB, STAT3, inflammation-causing factors (cytokines, TNF-α, chemokines), and growth-regulating factors (VEGF, TGF-β), are vital regulators responsible for the instigation and resolution of inflammations. Moreover, the conventional chemotherapeutics have exhibited diverse limitations, including poor pharmacokinetics, unfavorable chemical properties, poor targetability to the disease-specific disease leading to toxicity; thus, their applications are restricted in inflammation-mediated cancer therapy. Furthermore, nanotechnology has demonstrated potential benefits over conventional chemotherapeutics, such as it protected the incorporated drug/bioactive moiety from enzymatic degradation within the systemic circulation, improving the physicochemical properties of poorly aqueous soluble chemotherapeutic agents, and enhancing their targetability in specified carcinogenic cells rather than accumulating in the healthy cells, leading reduced cytotoxicity. Among diverse nanomaterials, polyester-based nanoparticulate delivery systems have been extensively used to target various inflammation-mediated cancers. This review summarizes the therapeutic potentials of various polyester nanomaterials (PLGA, PCL, PLA, PHA, and others)-based delivery systems targeting multiple signaling pathways related to inflammation-mediated cancer.

Catalytic nanomedicine: a brief review of bionanocatalysts

Catalytic nanomedicine is a research area and source of disruptive technology that studies the application of bionanocatalysts (organically functionalized mesoporous nanostructured materials with catalytic properties) in diverse areas such as disinfection, tissue regeneration in chronic wounds and oncology. This paper reviews the emergence of catalytic nanomedicine in 2006, its basic principles, main achievements and future perspectives, as well as giving a summary of the knowledge gaps that need to be addressed to exploit the full potential of this novel discipline. This review intends to foster knowledge dissemination regarding catalytic nanomedicine, and to encourage further research to elucidate the mechanisms and possible applications of these nanomaterials.

Engineered Nanoscale Lipid-Based Formulation as Potential Enhancer of Gefitinib Lymphatic Delivery: Cytotoxicity and Apoptotic Studies Against the A549 Cell Line

The present study aimed to engineer a nanoscale lipid-based lymphatic drug delivery system with D-α-Tocopherol polyethylene glycol 1000 succinate to combat the lymphatic metastasis of lung cancer. The nanoscale lipid-based systems including GEF-SLN, GEF-NLC, and GEF-LE were prepared and pharmaceutically characterized. In addition, the most stable formulation (GEF-NLC) was subjected to an in vitro release study. Afterward, the optimized GEF-NLC was engineered with TPGS (GEF-TPGS-NLC) and subjected to in vitro cytotoxicity, and apoptotic studies using the A549 cells line as a surrogate model for lung cancer. The present results revealed that particle size and polydispersity index of freshly prepared formulations were ranging from 198 to 280 nm and 0.106 to 0.240, respectively, with negative zeta potential ranging from − 14 to − 27.6.mV. An in vitro release study showed that sustained drug release was attained from GEF-NLC containing a high concentration of lipid. In addition, GEF-NLC and GEF-TPGS-NLC showed remarkable entrapment efficiency above 89% and exhibited sustained release profiles. Cytotoxicity showed that IC₅₀ of pure GEF was 11.15 μg/ml which decreased to 7.05 μg/ml for GEF-TPGS-NLC. The apoptotic study revealed that GEF-TPGS-NLC significantly decreased the number of living cells from 67 to 58% when compared with pure GEF. The present results revealed that the nanoscale and lipid composition of the fabricated SLN, NLC, and LE could mediate the lymphatic uptake of GEF to combat the lymphatic tumor metastasis. Particularly, GEF-TPGS-NLC is a promising LDDS to increase the therapeutic outcomes of GEF during the treatment of metastatic lung cancer.

Abemaciclib-loaded ethylcellulose based nanosponges for sustained cytotoxicity against MCF-7 and MDA-MB-231 human breast cancer cells lines

Abemaciclib (AC) is a novel, orally available drug molecule approved for the treatment of breast cancer. Due to its low bioavailability, its administration frequency is two to three times a day that can decrease patient compliance. Sustained release formulation are needed for prolong the action and to reduce the adverse effects. The aim of current study was to develop sustained release NSs of AC. Nanosponges (NSs) was prepared by emulsion-solvent diffusion method using ethyl-cellulose (EC) and Kolliphor P-188 (KP-188) as sustained-release polymer and surfactant, respectively. Effects of varying surfactant concentration and drug: polymer proportions on the particle size (PS), polydispersity index (PDI), zeta potential (ζP), entrapment efficiency (%EE), and drug loading (%DL) were investigated. The results of AC loaded NSs (ACN1-ACN5) exhibited PS (366.3–842.2 nm), PDI (0.448–0.853), ζP (−8.21 to −19.7 mV), %EE (48.45–79.36%) and %DL (7.69–19.17%), respectively. Moreover, ACN2 showed sustained release of Abemaciclib (77.12 ± 2.54%) in 24 h Higuchi matrix as best fit kinetics model. MTT assay signified ACN2 as potentials cytotoxic nanocarrier against MCF-7 and MDA-MB-231 human breast cancer cells. Further, ACN2 displayed drug release property without variation in the % release after exposing the product at 25 °C, 5 °C, and 45 °C storage conditions for six months. This investigation proved that the developed NSs would be an efficient carrier to sustain the release of AC in order to improve efficacy against breast cancer.

Green Synthesis and Potential Antibacterial Applications of Bioactive Silver Nanoparticles: A Review

Green synthesis of silver nanoparticles (AgNPs) using biological resources is the most facile, economical, rapid, and environmentally friendly method that mitigates the drawbacks of chemical and physical methods. Various biological resources such as plants and their different parts, bacteria, fungi, algae, etc. could be utilized for the green synthesis of bioactive AgNPs. In recent years, several green approaches for non-toxic, rapid, and facile synthesis of AgNPs using biological resources have been reported. Plant extract contains various biomolecules, including flavonoids, terpenoids, alkaloids, phenolic compounds, and vitamins that act as reducing and capping agents during the biosynthesis process. Similarly, microorganisms produce different primary and secondary metabolites that play a crucial role as reducing and capping agents during synthesis. Biosynthesized AgNPs have gained significant attention from the researchers because of their potential applications in different fields of biomedical science. The widest application of AgNPs is their bactericidal activity. Due to the emergence of multidrug-resistant microorganisms, researchers are exploring the therapeutic abilities of AgNPs as potential antibacterial agents. Already, various reports have suggested that biosynthesized AgNPs have exhibited significant antibacterial action against numerous human pathogens. Because of their small size and large surface area, AgNPs have the ability to easily penetrate bacterial cell walls, damage cell membranes, produce reactive oxygen species, and interfere with DNA replication as well as protein synthesis, and result in cell death. This paper provides an overview of the green, facile, and rapid synthesis of AgNPs using biological resources and antibacterial use of biosynthesized AgNPs, highlighting their antibacterial mechanisms.

Recent development of imidazole derivatives as potential anticancer agents

Cancer, one of the key health problems globally, is a group of related diseases that share a number of characteristics primarily the uncontrolled growth and invasive to surrounding tissues. Chemotherapy is one of the ways for the treatment of cancer which uses one or more anticancer agents as per chemotherapy regimen. Limitations of most anticancer drugs due to a variety of reasons such as serious side effects, drug resistance, lack of sensitivity and efficacy etc. generate the necessity towards the designing of novel anticancer lead molecules. In this regard, the synthesis of biologically active heterocyclic molecules is an appealing research area. Among heterocyclic compounds, nitrogen containing heterocyclic molecules has fascinated tremendous consideration due to broad range of pharmaceutical activity. Imidazoles, extensively present in natural products as well as synthetic molecules, have two nitrogen atoms, and are five membered heterocyclic rings. Because of their countless physiological and pharmacological characteristics, medicinal chemists are enthused to design and synthesize new imidazole derivatives with improved pharmacodynamic and pharmacokinetic properties. The aim of this present chapter is to discuss the synthesis, chemistry, pharmacological activity, and scope of imidazole-based molecules in anticancer drug development. Finally, we have discussed the current challenges and future perspectives of imidazole-based derivatives in anticancer drug development.

A novel rapid synthesis of highly stable silver nanoparticle/carbon quantum dot nanocomposites derived from low-grade coal feedstock

Coal-based highly stable carbon quantum dot/silver nanocomposites.

The Pharmacological Activities of Crocus sativus L.: A Review Based on the Mechanisms and Therapeutic Opportunities of its Phytoconstituents

Crocus species are mainly distributed in North Africa, Southern and Central Europe, and Western Asia, used in gardens and parks as ornamental plants, while Crocus sativus L. (saffron) is the only species that is cultivated for edible purpose. The use of saffron is very ancient; besides the use as a spice, saffron has long been known also for its medical and coloring qualities. Due to its distinctive flavor and color, it is used as a spice, which imparts food preservative activity owing to its antimicrobial and antioxidant activity. This updated review discusses the biological properties of Crocus sativus L. and its phytoconstituents, their pharmacological activities, signaling pathways, and molecular targets, therefore highlighting it as a potential herbal medicine. Clinical studies regarding its pharmacologic potential in clinical therapeutics and toxicity studies were also reviewed. For this updated review, a search was performed in the PubMed, Science, and Google Scholar databases using keywords related to Crocus sativus L. and the biological properties of its phytoconstituents. From this search, only the relevant works were selected. The phytochemistry of the most important bioactive compounds in Crocus sativus L. such as crocin, crocetin, picrocrocin, and safranal and also dozens of other compounds was studied and identified by various physicochemical methods. Isolated compounds and various extracts have proven their pharmacological efficacy at the molecular level and signaling pathways both in vitro and in vivo. In addition, toxicity studies and clinical trials were analyzed. The research results highlighted the various pharmacological potentials such as antimicrobial, antioxidant, cytotoxic, cardioprotective, neuroprotective, antidepressant, hypolipidemic, and antihyperglycemic properties and protector of retinal lesions. Due to its antioxidant and antimicrobial properties, saffron has proven effective as a natural food preservative. Starting from the traditional uses for the treatment of several diseases, the bioactive compounds of Crocus sativus L. have proven their effectiveness in modern pharmacological research. However, pharmacological studies are needed in the future to identify new mechanisms of action, pharmacokinetic studies, new pharmaceutical formulations for target transport, and possible interaction with allopathic drugs.

Biodegradable self-assembly micelles significantly enhanced the solubility, biological stability and in vivo antitumor efficacy of Hexylselen

Glutaminolysis inhibitors have shown early promise in cancer therapeutics. Specifically, kidney-type glutaminase (KGA) has been a long-standing anti-tumor drug target; KGA allosteric inhibitors have attracted great attention due to their superior enzyme specificity and good drug safety profiles. However, the main issue with allosteric inhibitors—including BPTES, CB-839, and the recently developed KGA allosteric and glutamate dehydrogenase (GDH) dual inhibitor, Hexylselen (CPD-3B)—is their low solubility; it leads to limited in vivo efficacy. To optimize their formulation, various delivery carriers were screened in the present study. Soluplus® (SOL), an amphiphilic graft polymer, showed an interesting structure–solubility/activity relationship with Selen molecules containing different middle chain sizes. Among these molecules, the long chain molecule CPD-3B showed 3000-fold increased solubility with SOL, forming well-dispersed and stable micelles 60–80 nm in size. Moreover, CPD-3B@SOL micelles exhibited good metabolic stability in both blood and liver microsomes. These advantages significantly enhanced the bioavailability and in vivo antitumor efficacy of CPD-3B@SOL micelles in the H22 hepatocarcinoma xenograft mouse model. Thus, the current study provided a practical delivery system for allosteric inhibitors of glutaminase, which is one of the bottlenecks of targeting tumor glutaminolysis.

Soluplus increased the aqueous solubility of Hexylselen (CPD-3B) by about 3000-fold forming nano-sized micelles, significantly enhanced the stability in blood and liver microsomes and improved the in vivo bioavailability and antitumor efficacy.

Surface modification with cholesteryl acetyl carnitine, a novel cationic agent, elevates cancer cell uptake of the PEGylated liposomes

The present study aimed to synthesize cholesteryl acetyl carnitine (CAC), and surface modify the PEGylated liposomes with the intention of enhanced cancer cell uptake. For this, CAC synthesis was performed in amine-free esterification conditions and then four liposomal formulations of unmodified, CAC/PEG, and CAC + PEG-modified were prepared by ethanol injection method. Cytotoxicity of the liposomes was investigated in A549 cells, followed by cellular uptake assessments of coumarin 6 (C6)-loaded liposomes. The results of ATR-FTIR, ¹HNMR, and ¹³CNMR demonstrated successful formation of CAC. A molecular docking study showed efficient binding affinities rather than carnitine to the active site of four carnitine transporters. Liposomal formulations possessed spherical morphology with a mean particle size range of 112-138 nm, narrow size distribution, and negative surface charge. All formulations had low cytotoxicity at 0.5 mg/ml, but high cytotoxicity at around 2.5 mg/ml. The lowest IC50 was obtained for CAC modified liposomes. CAC + PEG-modified liposomes had the highest cellular uptake. In conclusion, CAC + PEG modification of liposomes is an effective approach for increasing A549 cellular uptake, with low cytotoxicity at commonly applied liposome concentrations. The elevated uptake may be due to the involvement of the organic cation transporter, cationic structure, and the metabolic preference of CAC in cancer cells.

Targeted combined therapy in 2D and 3D cultured MCF-7 cells using metformin and erlotinib-loaded mesoporous silica magnetic nanoparticles

AIM

This research aims to develop potential therapeutic nanostructures (NSs) encapsulating metformin (MET) and erlotinib (ER) for combinational therapy in breast cancer.

METHODS

The ER and MET, both were loaded on mesoporous silica magnetic nanoparticles conjugated with polyethylene glycol and methotrexate to achieve targeted NSs. The developed NSs were characterised using SEM, DLS, and FTIR. Afterward, MTT, Trypan blue, and DNA extraction assays were operated for biological evaluations in the 2D and 3D MCF-7 cells.

RESULTS

Physicochemical approaches indicated the mean diameter of 69.4 nm ± 9.5 (PDI = 0.64), and neutral charge (2 mv) for the developed NSs. MET and ER-loaded NSs exhibited 62.56% ± 4.41 and 67.73% ± 3.03 drug release amount in pH = 5.4, respectively. MTT assay revealed that ER- and MET-loaded NSs had less metabolic activity (≈ 20%) in comparison with non-targeted NSs.

CONCLUSION

Overall, our combined ER and MET-loaded targeted NSs result in a synergistic inhibitory impact on MCF-7 cells.

Silver Nanodot Decorated Dendritic Copper Foam As a Hydrophobic and Mechano-Chemo Bactericidal Surface

The present work investigates the time-dependent antibacterial activity of the silver nanodot decorated dendritic copper foam nanostructures against Escherichia coli (Gram-negative) and Bacillus subtilis (Gram-positive) bacteria. An advanced antibacterial and antifouling surface is fabricated utilizing the collective antibacterial properties of silver nanodots, chitosan, and dendritic copper foam nanostructures. The porous network of the Ag nanodot decorated Cu foam is made up of nanodendrites, which reduce the wettability of the surface. Hence, the surface exhibits hydrophobic nature and inhibits the growth of bacterial flora along with the elimination of dead bacterial cells. The fabricated surface exhibits a water contact angle (WCA) of 158.7 ± 0.17°. Specifically, we tested the fabricated material against both the Gram-positive and Gram-negative bacterial models. The antibacterial activity of the fabricated surface is evident from the growth inhibition percentage of bacterial strains of Escherichia coli (72.30 ± 0.60%) and Bacillus subtilis (48.30 ± 1.71%). The micrographs obtained from scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) of the treated cells show the damaged cellular structures of the bacteria, which is strong evidence of successful antibacterial action. The antibacterial effect can be attributed to the synergistic mechano-chemo mode of action involving mechanical disruption of the bacterial cell wall by the nanoprotrusions present on the Cu dendrites along with the chemical interaction of the Ag nanodots with vital intracellular components.

In-vitro evaluation of antioxidant and anticholinesterase activities of novel pyridine, quinoxaline and s-triazine derivatives

Cholinesterase enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) cause hydrolysis of acetylcholine (ACh), a neurotransmitter responsible for the cognitive functions of the brain such as acquiring knowledge and comprehension. Therefore, inhibition of these enzymes is an effective process to curb the progressive and fatal neurological Alzheimer's disease (AD). Herein, we explored the potential inhibitory activities of various pyridine, quinoxaline, and triazine derivatives (3a-k, 6a-j and 11a-h) against AChE and BuChE enzymes by following the modified Ellman's method. Further, anti-oxidant property of these libraries was monitored using DPPH (2,2'-diphenyl-1-picryl-hydrazylhydrate) radical scavenging analysis. From the studies, we identified that compounds 6e, 6f, 11b and 11f behaved as selective AChE inhibitors with IC₅₀ values ranging from 7.23 to 10.35 μM. Further studies revealed good anti-oxidant activity by these compounds with IC₅₀ values in the range of 14.80-27.22 μM. The kinetic studies of the active analogues demonstrated mixed-type of inhibition due to their interaction with both the catalytic active sites (CAS) and peripheral anionic sites (PAS) of the AChE. Additionally, molecular simulation in association with fluorescence and circular dichroism (CD) spectroscopic analyses explained strong affinities of inhibitors to bind with AChE enzyme at the physiological pH of 7.2. Binding constant values of 5.4 × 10⁴, 4.3 × 10⁴, 3.2 × 10⁴ and 4.9 × 10⁴ M^-1 corresponding to free energy changes -5.593, -6.799, -6.605 and -8.104 KcalM^-1 were obtained at 25 °C from fluorescence emission spectroscopic studies of 6e, 6f, 11b and 11f, respectively. Besides, CD spectroscopy deliberately explained the secondary structure of AChE partly unfolded upon binding with these dynamic molecules. Excellent in vitro profiles of distinct quinoxaline and triazine compounds highlighted them as the potential leads compared to pyridine derivatives, suggesting a path towards developing preventive or therapeutic targets to treat the Alzheimer's disease.

Local Anesthetic Lidocaine and Cancer: Insight Into Tumor Progression and Recurrence

Cancer is a leading contributor to deaths worldwide. Surgery is the primary treatment for resectable cancers. Nonetheless, it also results in inflammatory response, angiogenesis, and stimulated metastasis. Local anesthetic lidocaine can directly and indirectly effect different cancers. The direct mechanisms are inhibiting proliferation and inducing apoptosis via regulating PI3K/AKT/mTOR and caspase-dependent Bax/Bcl2 signaling pathways or repressing cytoskeleton formation. Repression invasion, migration, and angiogenesis through influencing the activation of TNFα-dependent, Src-induced AKT/NO/ICAM and VEGF/PI3K/AKT signaling pathways. Moreover, the indirect influences are immune regulation, anti-inflammation, and postoperative pain relief. This review summarizes the latest evidence that revealed potential clinical benefits of lidocaine in cancer treatment to explore the probable molecular mechanisms and the appropriate dose.

Computational Study on the Mechanism of the Photouncaging Reaction of Vemurafenib: Toward an Enhanced Photoprotection Approach for Photosensitive Drugs

The photochemical behavior of the photosensitive first-line anticancer drug vemurafenib (VFB) is of great interest due to the impact of such behavior on its pharmacological activity. In this work, we computationally elucidated the mechanism of the photoinduced release of VFB from the 4,5-dimethoxy-2-nitrobenzene (DMNB) photoprotecting group by employing various density functional theory (DFT)/time-dependent DFT (TD-DFT) approaches. The computational investigations included a comparative assessment of the influence of the position of the photoprotecting group as a substituent on the thermodynamics and kinetics of the photouncaging reactions of two VFB-DMNB prodrugs, namely pyrrole (N_P) and sulfonamide (N_S). With the aid of the DFT calculations concerning the activation energy barrier (∆G^‡), the obtained results suggest that the step of the photoinduced intramolecular proton transfer of the DMNB moiety is not detrimental concerning the overall reaction profile of the photouncaging reaction of both prodrugs. However, the obtained results suggested that the position of the substitution position of the DMNB photoprotecting group within the prodrug structure has a substantial impact on the photouncaging reaction. In particular, the DMNB-N_s-VFB prodrug exhibited a notable increase in ∆G^‡ for the key step of ring opining within the DMNB moiety indicative of potentially hindered kinetics of the photouncaging process compared with DMNB-N_p-VFB. Such an increase in ∆G^‡ may be attributed to the electronic influence of the N_P fragment of the prodrug. The results reported herein elaborate on the mechanism of the photoinduced release of an important anticancer drug from photoprotecting groups with the aim of enhancing our understanding of the photochemical behavior of such photosensitive pharmaceutical materials at the molecular level.

Selective targeting of cancer signaling pathways with nanomedicines: challenges and progress

Cancer is one of the leading causes of death worldwide. Regardless of advances in understanding the molecular mechanics of cancer, its treatment is still lacking and the death rates for many forms of the disease remain the same as six decades ago. Although a variety of therapeutic agents and strategies have been reported, these therapies often failed to provide efficient therapy to patients as a consequence of the inability to deliver right and adequate chemotherapeutic agents to the right place. However, the situation has started to revolutionize substantially with the advent of novel 'targeted' nanocarrier-based cancer therapies. Such therapies hold great potential in cancer management as they are biocompatible, tailored to specific needs, tolerated and deliver enough drugs at the targeted site. Their use also enhances the delivery of chemotherapeutics by improving biodistribution, lowering toxicity, inhibiting degradation and increasing cellular uptake. However, in some instances, nonselective targeting is not enough and the inclusion of a ligand moiety is required to achieve tumor targeting and enhanced drug accumulation at the tumor site. This contemporary review outlines the targeting potential of nanocarriers, highlighting the essentiality of nanoparticles, tumor-associated molecular signaling pathways, and various biological and pathophysiological barriers.