Preparation of Stable Silver Nanoparticle Containing Glycerol-AOT [bis(2-ethylhexyl)sulfosuccinate sodium salt] Reverse Micellar Solution using Hydrogen Gas as Reducing Agent and Silver Nitrate as Precursor Material

The research paper describes the synthesis of silver nanoparticles in nonaqueous AOT [bis (2-ethylhexyl) sulfosuccinate sodium salt] reverse micellar solution. Complete description of the reverse micellar system is glycerol-AOT-n-heptane reverse micelle where AOT molecules act as surfactant molecule, glycerol as non aqueous polar core solvent and n-heptane as nonpolar hydrocarbon which acts as the dispersion medium. In this study I have used glycerol as nonaqueous polar solvent which was used to create the AOT surfactant core of the reverse micelle and then incorporated silver ion (Ag+) using silver nitrate (AgNO3) salt as precursor material responsible for metal nanoparticle formation. Freshly prepared hydrogen gas (H2) is used as reducing agent to reduce silver ion (Ag+) to silver zero (Ag0) state. Formation and precipitation of large particle was restricted by the cage like templating structure of reverse micelle. I have selected hydrogen gas as reducing agent because of its mild nature and also wanted to minimize the perturbation of natural reverse micelle environment &nbsp

Development of Novel Therapeutic Strategies for Pancreatic Cancer Treatment

Pancreatic cancer (PanCa) is the third deadliest cancer in the USA due to the late diagnosis and development of chemo-resistance, with a 5-year survival rate of less than 10%. The prognosis of patients with pancreatic ductal adenocarcinoma is extremely poor, and current therapies such as Gemcitabine, 5-FU, Nab-paclitaxel and, FOLFIRINOX alone or in combination, have displayed improved but marginal survival rates for patients. Therefore, research efforts are underway to discover new therapeutic options to treat PanCa and overcome resistance to available therapies. Mucin, MUC13 is transmembrane glycoprotein, which is aberrantly overexpressed in PanCa and promoting cancer growth. Structural domains of MUC13, lead to oncogenic characteristics during cancer progression. Our lab previously established the role of MUC13 in tumor progression and metastasis by alteration of signaling pathways. Recent observations suggest the role of MUC13 in drug resistance and apoptosis in several cancer types. Therefore, it is of great interest to explore the role of MUC13 in chemoresistance in PanCa. Unlike other cancer types, PanCa is highly resistant to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) that emerges as one of the most-promising cancer therapeutic drugs. It is a death ligand that can selectively induce apoptosis in cancer cells over normal cells. Our recent work has demonstrated that MUC13 expressing cells showed resistance to TRAIL induced cell death and MUC13 knockdown leads to TRAIL sensitivity in cells. We have also observed that MUC13 expression blocks the activation of caspase-8 and Bid in PanCa cells in response to TRAIL treatment. Further investigation showed that alpha and beta domains of MUC13 are indispensable for blocking caspase-8 activation and PARP cleavage, indicating that the MUC13 blocks TRAIL-induced signaling upstream to Bid by inhibiting caspase-8 activation. Current studies revealed a new role of MUC13 ininhibiting TRAIL mediated activation of extrinsic apoptotic pathway in pancreatic cancer. MicroRNAs (miRNA) have been identified as attractive targets for therapeutic intervention. The functional significance of lost miRNAs have been reported in several human malignancies, including PanCa. Restitution of lost miRNA function can provide a potential therapeutic benefit. Prior work has identified microRNA-145 (miR-145) as a tumor suppressor miRNA in PanCa. The restoration of miR-145 downregulates a number of oncogenes including mucin MUC13 and efficiently inhibits tumor growth in mice. Inhibition of MUC13 using miR-145 restoration resulted in TRAIL mediated increase in apoptotic cell death as evidenced by sub-G0 population and inhibition of MUC13, activation of caspase 8 and, cleavage of PARP-1. MiR-145 replacement can sensitize TRAIL therapy and counteract chemoresistance mechanism in PanCa. The main challenge for successful translation of miRNAs into clinical practice remains an effective in vivo delivery system. Hence, the focus of this study was to develop and assess the efficacy of a miR-145 based nanoparticle formulation for PanCa treatment. Magnetic nanoparticle (MNP) based nanoformulation of miR-145 (miR-145-MNPF) was developed for the intracellular delivery and sustained release of miR-145. The positively charged polyethyleneimine molecules were used to increase the loading efficiency of miR-145. Treatment of cells with miR-145-MNPF led to efficient intracellular delivery of miR-145 mimics as observed through Prussian blue staining. This led to the simultaneous upregulation of miR-145 levels in cells which resulted in significant downregulation of target oncogenes including MUC13, HER2, pAKT and p53. miR-145-MNPF efficiently restores miR-145 in PanCa cells and inhibits growth and invasion of PanCa. miR-145 restitution using miR-145-MNPF may offer a potential therapeutic strategy for pancreatic cancer. As discussed earlier that miR-145 restoration sensitized the TRAIL therapy in PanCa cells. Herein, we demonstrate the integration of novel delivery approach to reduce the delivery challenge of TRAIL. We have engineered unique superparamagnetic nanoparticles (MNPs) for co-delivering miR-145 and plasmid TRAIL for improving TRAIL response in PanCa model. MNP-miR-145-TRAIL nanoparticles were codelivered miR-145 and TRAIL to PanCa cells, which resulted in simultaneous restoration of miR-145 and inhibition of acquired resistance to TRAIL. The current study demonstrates that acquired resistance to TRAIL in PanCa cells can be minimized with the replenishment of miR-145 expression. Combined actions of miR-145 and TRAIL markedly improve TRAIL-induced apoptotic effects in PanCa cells through the activation of an extrinsic apoptosis pathway as indicated by activation of DR4, FLIP, FADD and enhanced expression of cleaved caspase-8. The co-delivery of miR-145 and TRAIL using MNP nanoparticles inhibited tumorigenic characteristics of PanCa cells. The results were reciprocated and were further confirmed with the inhibition of tumorsphere formation and in vivo tumorigenicity in xenograft mice. Immunohistochemical staining of excised tumor tissues demonstrates an activation of the death receptor pathway and subsequent expression of apoptotic markers. Pancreatic tumor microenvironment is a complex dynamic space which leads to desmoplasia and involved in metastasis and impediments against intracellular drug delivery. Despite extensive research efforts, there is not considerable progress in cancer therapeutics due to genomic complexity and heterogenicity of pancreatic cancer. Modern tumor therapy must be patient specific and customized for individual patients. It should be tailored for a patient-based response to the specific treatment. Thus, novel delivery vehicles are required that are biocompatible and non-immunogenic. This is possible by utilizing an autologous biological material as delivery vehicles that can be applied as a personalized medicine. Towards this, our lab has optimized an exosome based therapeutic approach, which utilizes exosomes isolated from the cultured tumor adjacent normal (NAT) fibroblast cells. We utilized this scaffold for safe and effective delivery of therapeutic payload. Our results demonstrated that NAT derived exosomal formulation (Exo-ORM) significantly enhanced the efficacy of ormeloxifene to inhibit stroma as indicated by decreased expression of α-SMA, desmin and hyaluronic acid. Exo-ORM formulation effectively inhibit EMT/SHH signaling in PanCa cells and in vivo models. NAT derived exosomes will be a promising therapeutic carrier with preferential size for passive targeting, proficient biophysical characteristics, biocompatible and nonimmunogenic vehicle for PanCa therapy

Short Fibre and Particulate-reinforced Rubber Composites

Particulate fillers (carbon black and silica) and short fibre (aromatic polyamide, Kevlar have been utilised to produce rubber composites based on acrylonitrile-co-butadiene rubber (NBR). Mechanical properties of these composites have been determined and compared with unfilled rubber vulcanisate. The effect of surface treatment on the improvement of strength, in case of Kevlar, has also been considered. The influence of elevated temperature on tear strength, an important failure criterion, has been evaluated. Scanning electron microscopy has been used as a tool to correlate the topographical features associated with changes in the tear strength of the composites

A Brief Overview on Ferrite (Fe3O4) Based Polymeric Nanocomposites: Recent Developments and Challenges

In this article, we have mainly discussed about ferrite (Fe3O4) and its polymer based nanocomposites. Ferrite particles have become an important research material because of their vast applications in the field of biotechnology, magnetic resonance imaging (MRI), and data storage. It has been observed that ferrite Fe3O4 particles show best performance for size less than 10-30 nm. This happens due to the super paramagnetic nature of such particles. In super paramagnetic range these particles exhibit zero remanence or coercivity. Therefore, various properties of ferrite (Fe3O4) nanoparticles and its polymer nanocomposites are very much dependent on the size, and distribution of the particles in the polymeric matrix. Moreover, it has been also observed that the shape of the nanocrystals plays important role in the determination of their fundamental properties. These particles show instability over longer times due to the formation of agglomerates generated by high surface energies. Therefore, protection strategies such as grafting and coatings with silica/carbon or polymers have been developed to stabilize them chemically. Recently, silylation technique is mainly used for the modification of nanoparticles. Experimentally, it has been observed that nanocomposites composed of polymer matrices and ferrite showed substantial improvements in stiffness, fracture toughness, sensing ability (magnetic as well as electric), impact energy absorption, and electro-catalytic activities to bio-species

Cold atmospheric plasma induces ATP-dependent endocytosis of nanoparticles and synergistic U373MG cancer cell death

Gold nanoparticles (AuNP) have potential as both diagnostic and therapeutic vehicles. However, selective targeting and uptake in cancer cells remains challenging. Cold atmospheric plasma (CAP) can be combined with AuNP to achieve synergistic anti-cancer cytotoxicity. To explore synergistic mechanisms, we demonstrate both rate of AuNP uptake and total amount accumulated in U373MG Glioblastoma multiforme (GBM) cells are significantly increased when exposed to 75 kV CAP generated by dielectric barrier discharge. No significant changes in the physical parameters of AuNP were caused by CAP but active transport mechanisms were stimulated in cells. Unlike many other biological effects of CAP, long-lived reactive species were not involved, and plasma-activated liquids did not replicate the effect. Chemical effects induced by direct and indirect exposure to CAP appears the dominant mediator of enhanced uptake. Transient physical alterations of membrane integrity played a minor role. 3D-reconstruction of deconvoluted confocal images confirmed AuNP accumulation in lysosomes and other acidic vesicles, which will be useful for future drug delivery and diagnostic strategies. Toxicity of AuNP significantly increased by 25-fold when combined with CAP. Our data indicate that direct exposure to CAP activates AuNP-dependent cytotoxicity by increasing AuNP endocytosis and trafficking to lysosomes in U373MG cells

Synthesis and characterization of Cadmium (II) complex with tetradentate N2O2- donor Schiff base and biological activity

Transition metal complex of Cd (II) with tetradentate schiff base derived from the condensation of 4-nitro-1,2-diamino benzene and 5-nitro-salicyldehyde (H2L) have been synthesized. The synthesized square planar complex was investigated using elemental analysis (C, H and N), infrared, conductivity and electronic spectroscopic tools. The interactions of cadmium (II) complex examined towards Bovine serum albumin (BSA) with the help of absorption and fluorescence spectroscopic tools. The complex is strongly binds to proteins, then we study the antibacterial activity of the Schiff base and its cadmium complex by agar disc diffusion method against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia and Bacillus cereus).The result indicated that cadmium complex was more activity than ligand due to higher lipophilicity effect. &nbsp

Antibody mediated Targeted Drug Delivery approach for Pancreatic Tumors

Background: Pancreatic ductal adenocarcinomas, originating from the epithelial cell lining of ducts, account for approximately 95% of tumors in this category, showcasing a survival rate of less than 5-7%. Unfortunately, little progress has been seen in the outcomes of patients with PDAC as tumor develops high desmoplasia and chemo-resistance to chemotherapeutic drugs, such as gemcitabine (Gem). The therapies are unable to penetrate to the fibrotic tumors leading to insufficient availability of the therapeutic drugs at the tumor site. We and others have shown that MUC13 is aberrantly expressed in pancreatic tumors but not in normal pancreas, which makes MUC13 as an excellent protein for specifically targeting pancreatic tumors. Herein, we demonstrate a unique ability of our in-house generated mouse and humanized monoclonal antibody of MUC13 to penetrate and target pancreatic cancer. Methods: These antibodies have been conjugated with our recently developed novel patented superparamagnetic iron oxide nanoparticles (SPIONS) to deliver therapeutics specifically to pancreatic tumors. In this study, we are using curcumin that depletes tumor microenvironment and gemcitabine to investigate the efficacy of the MUC13 conjugated SPION in delivery of therapeutic drugs. Results: Our results demonstrate that enhanced uptake of MUC13-SPION formulation in MUC13 positive (MUC13+) PanCa cells, compared with MUC13 null (MUC13-) cells as demonstrated by immunofluorescence, Prussian blue staining and flow cytometry experiments. Interestingly, the formulation resulted in sustained delivery of curcumin (CUR), enhanced inhibition of cell proliferation, migration and invasion in MUC13+ cells as compared with MUC13- cells, which suggests the targeting efficacy of the formulation. In PanCa orthotopic mice model, MUC13- SPION efficiently targeted pancreatic tumors resulting in significant tumor accumulation. We observed inhibition of tumor volume, metastasis, gem resistance and improved survival in mice treated with the formulation. Additionally, the tumor tissues from treated mice showed extensive downregulation of PCNA and expression of key proteins in SHH pathway, such as SHH, Gli-1, Gli-2, Patched 1, SMO, which has been associated with cancer progression and drug resistance. Conclusion: In conclusion, the results indicate high therapeutic significance of MUC13-SPIONS for achieving pancreatic tumor specific delivery of drugs

MicroRNA-145 replacement as a therapeutic tool to Improve TRAIL therapy

Pancreatic cancer (PanCa) is a third leading cause of cancer related deaths in US. Unlike other cancers, PanCa is highly resistant to TNF-related apoptosis-inducing ligand (TRAIL) that emerges as one of the most-promising therapy in clinical trials. Our group has previously identified microRNA-145 (miR-145) is downregulated in PanCa, the restoration of which inhibits tumor growth and enhances gemcitabine sensitivity. In this study, we have observed that miR-145 restoration in PanCa cells renders them sensitive to TRAIL treatment. Therefore, we have engineered unique superparamagnetic nanoparticles (Magix) for codelivering miR-145 and TRAIL in PanCa for improving their therapeutic response to TRAIL. The results in this study demonstrate that acquired resistance to TRAIL in PanCa cells can overcome with the replacement of lost levels of miR-145 expression. Our formulation was engineered to co-deliver miR-145 and TRAIL to PanCa cells, which resulted in simultaneous restoration of miR-145 and inhibition of acquired resistance to TRAIL. Combined actions of miR-145 and TRAIL markedly improve TRAIL-induced apoptotic effects in PanCa cells through the activation of an extrinsic apoptosis pathway pathway as indicated by activation of DR5, FLIP, FADD and enhanced expression of caspase-8/3. The co-delivery of miR-145 and TRAIL using Magix inhibited tumorigenic characteristics of PanCa cells, which include proliferation, invasion, migration and clonogenicity. The results were reciprocated and got further confirmed with the inhibition of tumorsphere formation and in vivo tumorigencity in xenograft mice. Immunohistochemical staining of excised tumor tissues demonstrate an activation of death receptor pathway and subsequent expression of apoptotic markers. The study provides novel insights on two facades- how resistance of cancer cells to TRAIL-based pro-apoptotic therapies can be tackled, and how efficient intracellular delivery of TRAIL can be achieved. Our results suggest that acquired resistance to TRAIL can be overcome by co-delivery of miR-145 and pEGFP-TRAIL using Magix