What samples are suitable for monitoring antimicrobial-resistant genes? Using NGS technology, a comparison between eDNA and mrDNA analysis from environmental water.

Introduction: The rise in antimicrobial resistance (AMR) that is affecting humans, animals, and the environment, compromises the human immune system and represents a significant threat to public health. Regarding the impact on water sanitation, the risk that antimicrobial-resistant genes (ARGs) and antimicrobial-resistant bacteria in surface water in cities pose to human health remains unclear. To determine the prevalence of AMR in environmental surface water in Japan, we used DNA sequencing techniques on environmental water DNA (eDNA) and the DNA of multidrug-resistant bacteria (mrDNA). Methods: The eDNA was extracted from four surface water samples obtained from the Tokyo area and subjected to high- throughput next-generation DNA sequencing using Illumina-derived shotgun metagenome analysis. The sequence data were analyzed using the AmrPlusPlus pipeline and the MEGARes database. Multidrug-resistant bacteria were isolated using a culture-based method from water samples and were screened by antimicrobial susceptibility testing (for tetracycline, ampicillin-sulbactam, amikacin, levofloxacin, imipenem, and clarithromycin). Of the 284 isolates, 22 were identified as multidrug-resistant bacteria. The mrDNA was sequenced using the Oxford nanopore MinION system and analyzed by NanoARG, a web service for detecting and contextualizing ARGs. Results and discussion: The results from eDNA and mrDNA revealed that ARGs encoding beta-lactams and multidrug resistance, including multidrug efflux pump genes, were frequently detected in surface water samples. However, mrDNA also revealed many sequence reads from multidrug-resistant bacteria, as well as nonspecific ARGs, whereas eDNA revealed specific ARGs such as pathogenic OXA-type and New Delhi metallo (NDM)-beta-lactamase ARGs. Conclusion: To estimate potential AMR pollution, our findings suggested that eDNA is preferable for detecting pathogen ARGs.

Development and Evaluation of Polyvinylpyrrolidone K90 and Poloxamer 407 Self-Assembled Nanomicelles: Enhanced Topical Ocular Delivery of Artemisinin.

Age-related macular degeneration is a multifactorial disease affecting the posterior segment of the eye and is characterized by aberrant nascent blood vessels that leak blood and fluid. It ends with vision loss. In the present study, artemisinin which is poorly water-soluble and has potent anti-angiogenic and anti-inflammatory properties was formulated into nanomicelles and characterized for its ocular application and anti-angiogenic activity using a CAM assay. Artemisinin-loaded nanomicelles were prepared by varying the concentrations of PVP k90 and poloxamer 407 at different ratios and showed spherical shape particles in the size range of 41-51 nm. The transparency and cloud point of the developed artemisinin-loaded nanomicelles was found to be 99-94% and 68-70 °C, respectively. The in vitro release of artemisinin from the nanomicelles was found to be 96.0-99.0% within 8 h. The trans-corneal permeation studies exhibited a 1.717-2.169 µg permeation of the artemisinin from nanomicelles through the excised rabbit eye cornea for 2 h. Drug-free nanomicelles did not exhibit noticeable DNA damage and showed an acceptable level of hemolytic potential. Artemisinin-loaded nanomicelles exhibited remarkable anti-angiogenic activity compared to artemisinin suspension. Hence, the formulated artemisinin-loaded nanomicelles might have the potential for the treatment of AMD.

Tannic acid prevents macrophage-induced pro-fibrotic response in lung epithelial cells via suppressing TLR4-mediated macrophage polarization.

BACKGROUND: Polarized macrophages induce fibrosis through multiple mechanisms, including a process termed epithelial-to-mesenchymal transition (EMT). Mesenchymal cells contribute to the excessive accumulation of fibrous connective tissues, leading to organ failure. This study was aimed to investigate the effect of tannic acid (TA), a natural dietary polyphenol on M1 macrophage-induced EMT and its underlying mechanisms. MATERIALS: First, we induced M1 polarization in macrophage cell lines (RAW 264.7 and THP-1). Then, the conditioned-medium (CM) from these polarized macrophages was used to induce EMT in the human adenocarcinomic alveolar epithelial (A549) cells. We also analysed the role of TA on macrophage polarization. RESULTS: We found that TA pre-treated CM did not induce EMT in epithelial cells. Further, TA pre-treated CM showed diminished activation of MAPK in epithelial cells. Subsequently, TA was shown to inhibit LPS-induced M1 polarization in macrophages by directly targeting toll-like receptor 4 (TLR4), thereby repressing LPS binding to TLR4/MD2 complex and subsequent signal transduction. CONCLUSION: It was concluded that TA prevented M1 macrophage-induced EMT by suppressing the macrophage polarization possibly through inhibiting the formation of LPS-TLR4/MD2 complex and blockage of subsequent downstream signal activation. Further, our findings may provide beneficial information to develop new therapeutic strategies against chronic inflammatory diseases.

Tannic acid protects against experimental acute lung injury through downregulation of TLR4 and MAPK.

Acute lung injury (ALI) and its severe form acute respiratory distress syndrome (ARDS) remain a major cause of morbidity and mortality in critically ill patients, and no specific therapies are still available to control the mortality rate. Thus, we explored the preventive and therapeutic effects of tannic acid (TA), a natural polyphenol in the context of ALI. We used in vivo and in vitro models, respectively, using lipopolysaccharide (LPS) to induce ALI in mice and exposing J774 and BEAS-2B cells to LPS. In both preventive and therapeutic approaches, TA attenuated LPS-induced histopathological alterations, lipid peroxidation, lung permeability, infiltration of inflammatory cells, and the expression of proinflammatory mediators. In addition, in-vitro study showed that TA treatment could reduce the expression of proinflammatory mediators. Further studies revealed that TA-dampened inflammatory responses by downregulating the LPS-induced toll-like receptor 4 (TLR4) expression and inhibiting extracellular-signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) activation. Furthermore, cells treated with the inhibitors of ERK1/2 (PD98059) and p38 (SB203580) mitigated the expression of cytokines induced by LPS, thus suggesting that ERK1/2 and p38 activity are required for the inflammatory response. In conclusion, TA could attenuate LPS-induced inflammation and may be a potential therapeutic agent for ALI-associated inflammation in clinical settings.

Tannic acid modulates fibroblast proliferation and differentiation in response to pro-fibrotic stimuli.

In response to tissue injury, fibroblasts migrate into the wound, where they undergo proliferation and differentiation. The persistence of these differentiated fibroblasts (myofibroblasts) is associated with excessive scarring in various organs. We aimed to investigate the effects of Tannic acid (TA) on fibroblast proliferation and differentiation, and found that TA inhibited fibroblast differentiation as assessed by reduced expression of α-smooth muscle actin, N-cadherin, and type-1-collagen. TA also prevented the TGF-ß1-induced alteration in the expression of two classes of genes involved in the remodeling of extracellular matrix (ECM) proteins, namely matrix metalloproteinases (Mmp-2 and -9) and tissue inhibitors of metalloproteinases (Timp-1 and -3). Further, TA suppressed TGF-ß1-induced cell proliferation and induced cell cycle arrest at G0/G1 phase via targeting Cyclins expression. Finally, TA exerted its inhibitory effects by decreasing the phosphorylation of Smad and ERK signaling. In sum, our results suggesting that TA may be a potential therapeutic agent for pathological fibrosis.

Nepafenac loaded silica nanoparticles dispersed in-situ gel systems: Development and characterization.

This research was aimed to develop and evaluate nepafenac loaded silica nanoparticles dispersed in-situ gel system for the improved treatment of ocular diseases. The blank silica nanoparticles prepared by stober's process showed the particle size of 151 nm to 285 nm with the zeta potential of -19.6 to -31.9 mV. The nepafenac loaded silica nanoparticles were spherical in shape with smooth outer surface. The nepafenac loaded silica nanoparticles dispersed in poloxamer - chitosan in-situ gelling system showed gelling temperature of 32 °C with sustained release of nepafenac and higher permeation (58.79 µg) across the goat cornea than poloxamer - poloxamer (21.18 µg) in-situ gelling system. Hence the developed in-situ gelling system containing nepafenac loaded silica nanoparticle could be a promising tool for the topical delivery of drugs to the eye.

Tannic acid attenuates TGF-ß1-induced epithelial-to-mesenchymal transition by effectively intervening TGF-ß signaling in lung epithelial cells.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and an irreversible lung disorder characterized by the accumulation of fibroblasts and myofibroblasts in the extracellular matrix. The transforming growth factor-ß1 (TGF-ß1)-induced epithelial-to-mesenchymal transition (EMT) is thought to be one of the possible sources for a substantial increase in the number of fibroblasts/myofibroblasts in IPF lungs. Tannic acid (TA), a natural dietary polyphenolic compound has been shown to possess diverse pharmacological effects. However, whether TA can inhibit TGF-ß1-mediated EMT in lung epithelial cells remains enigmatic. Both the human adenocarcinomic alveolar epithelial (A549) and normal bronchial epithelial (BEAS-2B) cells were treated with TGF-ß1 with or without TA. Results showed that TA addition, markedly inhibited TGF-ß1-induced EMT as assessed by reduced expression of N-cadherin, type-1-collagen, fibronectin, and vimentin. Furthermore, TA inhibited TGF-ß1-induced cell proliferation through inducing cell cycle arrest at G0/G1 phase. TGF-ß1-induced increase in the phosphorylation of Smad (Smad2 and 3), Akt as well as that of mitogen activated protein kinase (ERK1/2, JNK1/2, and p38) mediators was effectively inhibited by TA. On the other hand, TA reduced the TGF-ß1-induced increase in TGF-ß receptors expression. Using molecular docking approach, FTIR, HPLC and Western blot analyses, we further identified the direct binding of TA to TGF-ß1. Finally, we conclude that TA might directly interact with TGF-ß1, thereby repressing TGF-ß signaling and subsequent EMT process in lung epithelial cells. Further animal studies are needed to clarify its potential therapeutic benefit in pulmonary fibrosis.

Development of copolymeric nanoparticles of hypocrellin B: Enhanced phototoxic effect and ocular distribution.

In the present work, we have developed a photosensitizer hypocrellin B (HB) and nano silver loaded PLGA-TPGS nanoparticles with improved singlet oxygen production for enhanced photodynamic effect for the efficient treatment of age related macular degeneration. Random copolymer (PLGA-TPGS) synthesized by ring opening and bulk polymerization was characterized by IR, 1H NMR and TGA analysis. HBS-CP-NPs prepared by nanoprecipitation techniques were spherical shaped 89.6-753.6nm size particles with negative zeta potential. The average encapsulation efficiency was 84.06±11.43% and HB release from the HBS-CP-NPs was found to be biphasic with a slow release of 1.41% in the first 8h and 48.91% during 3days as measured by RP-HPLC. DSC thermograms indicate that HB was dispersed as amorphous form in HBS-CP-NPs. The ROS generation level of HBS-CP-NPs was significantly higher than that of HB/HB-CP-NPs. The production of 1O2 of HBS-CP-NPs has been assessed using EPR spectrometer. The 1O2 generating efficiency follows the order of nano silver>HB-CP-NPs>HBS-CP-NPs>pure HB drug solution. The superior phototoxic effect of HBS-CP-NPs (85.5% at 50µM) was attained at 2h irradiation in A549 cells. Significant anti angiogenic effect of HBS-CP-NPs was observed in treated CAM embryos. Following intravenous injection of HBS-CP-NPs to rabbits, the maximum amount of HB was found in retina (3h), iris (9h), aqueous humour (9h) and vitreous humour (9h).

Development and evaluation of camptothecin loaded polymer stabilized nanoemulsion: Targeting potential in 4T1-breast tumour xenograft model.

Targeted delivery of anticancer agents is poised to improve cancer therapy, for which polymers can serve as targeting ligands or nanocarriers for chemotherapeutic agents. In this study, we have developed and evaluated the efficacy of a camptothecin (CPT)-loaded polymer stabilized nanoemulsion (PSNE) for the passive targeted delivery to breast cancer. Based on the pseudo-ternary phase diagrams, PSNEs were developed using capmul MCM:poloxamer 407 (4:1), solutol HS 15:simulsol P23 (1:2) and water. CPT polymer mixture was developed by solvent evaporation technique. The PSNEs were characterized for droplet size distribution, plasma protein adsorption, drug release, in-vivo targeting potential, hemolytic potential, cytotoxicity, genotoxicity, in-vivo biodistribution and CPT lactone ring stability. The developed PSNEs showed uniform droplet distribution, extended drug release (76.59±6.12% at 24h), acceptable hemolytic potential, significant cytotoxicity (IC50=176±4.3ng/mL) and genotoxicity against MCF-7 cancer cells but low DNA damage potential in human peripheral blood lymphocytes. The efficiency of PSNEs for the targeted delivery of CPT into the tumour regions was documented in 4T1-breast tumour xenografted BALB/c mice. In-vivo biodistribution study shows that 7105.84±568.46ng/g of CPT was passively targeted from PSNE to breast cancer tissue. About 80% of the lactone form was stable for 24h. Taken together, our study provides a promising strategy for developing PSNE-targeted drug delivery system for the breast cancer therapy.

Co-encapsulated resveratrol and quercetin in chitosan and peg modified chitosan nanoparticles: For efficient intra ocular pressure reduction.

Natural anti-oxidants resveratrol (RES) and quercetin (QUR) posses the ability to reduce intra ocular pressure efficiently. Concurrent administration of RES and QUR was able to enhance the bioavailability of RES. Present research work describes upsurge of QUR in RES loaded chitosan (CS) nanoparticles (NPs) and polyethylene glycol (PEG) modified CS NPs for improved delivery and synergic effects on reducing intra ocular pressure for the treatment of glaucoma. CS NPs and PEG modified CS NPs were prepared by ionic gelation of tripolyphosphate and CS. The synthesised NPs were spherical in shape and RES entrapment and loading efficiency in the formulation decreased with increasing PEG concentration. Particle size of the formulation increased while incorporating PEG and drugs. The crystalline nature of RES and QUR changed in the NPs and that was confirmed by XRD study. Free radical neutralising efficiency improved while incorporating QUR in the formulation. Ex-vivo corneal permeation of RES was higher from RES and QUR loaded formulation than RES alone containing NPs and free RES dispersion. RES and QUR loaded PEG modified CS NPs showed sustained and enhanced reduction of intra ocular pressure (5.5±0.5mmHg) in normotensive rabbits.

Chitosan stabilized camptothecin nanoemulsions: Development, evaluation and biodistribution in preclinical breast cancer animal mode.

Clinical use of camptothecin (CPT) is hindered due to its poor water and oil solubility, active lactone ring instability and non-targeted toxicity. Recently we reported formulation of camptothecin microemulsions with increased solubility for the improved treatment of breast cancer. In this research chitosan stabilized camptothecin nanoemulsions (CHI-CPT-NEs) were formulated improve the cancer targeting efficiency of CPT. The developed NEs were characterized for their droplet size distribution, stability in plasma and evaluated for in-vitro drug release, in-vivo targeting potential, in-vitro hemolytic potential, cytotoxicity, genotoxicity and in-vivo biodistribution. The CHI-CPT-NEs showed uniform droplet size distribution, extended drug release (61.65±1.57% at 24h), tolerable hemolytic potential (16.4±1.4%), significant cytotoxicity (178±4.3ng/ml) against MCF-7 cancer cells and low DNA damage to lymphocytes. In-vivo biodistribution study conducted in 4T1-breast tumor xenograft BALB/c mice showed that 2495.22±174.66ng/gm of camptothecin was passively targeted to breast cancer by CHI-CPT-NEs compared to the non-stabilized nanoemulsion (1677.58±134.21ng/gm). Thus, passive targeting of developed CHI-CPT-NEs may provide a promising approach for the efficient breast cancer therapy.

Artemisinin loaded chitosan magnetic nanoparticles for the efficient targeting to the breast cancer.

Artemisinin, a natural anti-malarial agent, also possesses anti-proliferative and anti-angiogenic activity in cancer cells with very low toxicity to normal healthy cells. Drug loaded magnetic nanoparticles by using external magnetic field could selectively accumulate the drug at the target site and thereby reduce the doses required to achieve therapeutic concentration which may otherwise produce serious side effects on healthy cells. In the present study the artemisinin magnetic nanoparticles were successfully formulated using chitosan by ionic-gelation method. The developed magnetic nanoparticles of artemisinin were smooth and spherical in nature and their size was in the range of 349-445nm. The polydispersity index (PDI) and zeta potential of the formulated nanoparticles were in the range of 0.373-0.908 and -9.34 to -33.3 respectively. They showed 55% to 62.5% of drug encapsulation efficiency and 20% to 25% drug loading capacity. Around 62% to 78% of artemisinin was released from the artemisinin magnetic nanoparticles over the period of 48h. On application of physiologically acceptable external magnetic field, FITC conjugated artemisinin magnetic nanoparticles showed an enhanced accumulation of nanoparticles in the 4T1 breast tumour tissues of BALB/c mice model.

C-phycocyanin suppresses transforming growth factor-ß1-induced epithelial mesenchymal transition in human epithelial cells.

BACKGROUND: Epithelial mesenchymal transition (EMT) is a process through which epithelial cells undergo multiple biochemical changes, causing them to differentiate into a mesenchymal-cell phenotype. This process has been shown to contribute to the development of fibrotic diseases. C-phycocyanin (C-PC) is a phycobiliprotein extracted from Spirulina platensis. This study was done to investigate the effect of C-PC on transforming growth factor-ß1 (TGF-ß1)-induced EMT and an EMT associated proliferation in human epithelial cell lines. METHODS: Human adenocarcinoma cell line, A549 and breast cancer cell line, MCF-7 were treated with TGF-ß1, and EMT-related genes expression, cell proliferation and cell cycle arrest were examined. RESULTS: C-PC suppressed the EMT as assessed by reduced expression of vimentin, type-1-collagen and fibronectin, and increased E-cadherin expression in TGF-ß1 treated cells. Further, TGF-ß1 treatment induced cell cycle arrest in S and G2/M phase in A549 cells. However, TGF-ß1-mediated cell cycle arrest was significantly reversed by combined treatment with C-PC. CONCLUSIONS: The overall data suggested that C-PC suppresses TGF- ß1-induced EMT and warrants further in vivo studies for future evaluation of C-PC as a potential antifibrotic agent.

Development and evaluation of magnetic microemulsion: tool for targeted delivery of camptothecin to BALB/c mice-bearing breast cancer.

PURPOSE: Development and evaluation of camptothecin-loaded-microemulsion (ME) and -magnetic microemulsion (MME) for passive/active-targeted delivery to BALB/c mice-bearing breast cancer. METHODS: Based on the pseudo-ternary phase diagrams camptothecin-loaded-MEs and -MMEs were developed using benzyl alcohol:Captex 300 (3:1), TPGS:Tween 80 (2:1) and water. Furthermore, characterized for their droplet size distribution, magnetic susceptibility and effect of droplet size in plasma and evaluated for in vitro and in vivo targeting potential, drug release, haemolytic potential, cytotoxicity, genotoxicity, in vivo biodistribution and lactone ring stability. RESULTS: Drug-loaded MEs showed uniform droplet distribution, extended drug release (76.07 ± 4.30% at 24 h), acceptable level of haemolytic activity (<20%), significant cytotoxicity (129 ± 3.9 ng/mL) against MCF-7 cancer cells and low DNA damage in lymphocytes. Targeting potential of MMEs was documented in 4T1 breast cancer-induced BALB/c mice. MMEs were concentrated more at the target tissue on introduction of external magnetic field. In vivo biodistribution study documented the active targeting of 5067.56 ± 354.72 ng/gm and passive targeting of 1677.58 ± 134.20 ng/gm camptothecin to breast cancer from MME and ME, respectively. Lactone stability study shows around 80% of the lactone stable at 24 h. CONCLUSIONS: Developed ME and MME may act as a promising nanocarrier for efficient targeting of breast cancer tissues.