Mechanisms and Impact of Biofilms and Targeting of Biofilms Using Bioactive Compounds-A Review.

Biofilms comprising aggregates of microorganisms or multicellular communities have been a major issue as they cause resistance against antimicrobial agents and biofouling. To date, numerous biofilm-forming microorganisms have been identified, which have been shown to result in major effects including biofouling and biofilm-related infections. Quorum sensing (which describes the cell communication within biofilms) plays a vital role in the regulation of biofilm formation and its virulence. As such, elucidating the various mechanisms responsible for biofilm resistance (including quorum sensing) will assist in developing strategies to inhibit and control the formation of biofilms in nature. Employing biological control measures (such as the use of bioactive compounds) in targeting biofilms is of great interest since they naturally possess antimicrobial activity among other favorable attributes and can also possibly act as potent antibiofilm agents. As an effort to re-establish the current notion and understanding of biofilms, the present review discuss the stages involved in biofilm formation, the factors contributing to its development, the effects of biofilms in various industries, and the use of various bioactive compounds and their strategies in biofilm inhibition.

Sodium alginate encapsulated iron oxide decorated with thymoquinone nanocomposite induces apoptosis in human breast cancer cells via PI3K-Akt-mTOR pathway.

The present study investigated the cytotoxicity and proapoptotic properties of iron oxide-sodium-alginate-thymoquinone nanocomposites against breast cancer MDA-MB-231 cells in vitro and in silico. This study used chemical synthesis to formulate the nanocomposite. Electron microscopies such as scanning (SEM) and transmission (TEM), Fourier transform infrared (FT-IR), Ultraviolet-Visible, Photoluminescence spectroscopy, selected area (electron) diffraction (SAED), energy dispersive X-ray analysis (EDX), and X-ray diffraction studies (XRD) were used to characterize the synthesized ISAT-NCs and the average size of them was found to be 55 nm. To evaluate the cytotoxic, antiproliferative, and apoptotic potentials of ISAT-NCs on MDA-MB-231 cells, MTT assays, FACS-based cell cycle studies, annexin-V-PI staining, ELISA, and qRT-PCR were used. PI3K-Akt-mTOR receptors and thymoquinone were predicted using in-silico docking studies. Cell proliferation is reduced in MDA-MB-231 cells due to ISAT-NC cytotoxicity. As a result of FACS analysis, ISAT-NCs had nuclear damage, ROS production, and elevated annexin-V levels, which resulted in cell cycle arrest in the S phase. The ISAT-NCs in MDA-MB-231 cells were found to downregulate PI3K-Akt-mTOR regulatory pathways in the presence of inhibitors of PI3K-Akt-mTOR, showing that these regulatory pathways are involved in apoptotic cell death. We also predicted the molecular interaction between thymoquinone and PI3K-Akt-mTOR receptor proteins using in-silico docking studies which also support PI3K-Akt-mTOR signaling inhibition by ISAT-NCs in MDA-MB-231 cells. As a result of this study, we can conclude that ISAT-NCs inhibit the PI3K-Akt-mTOR pathway in breast cancer cell lines, causing apoptotic cell death.

Synthesis, Characterization, and Antimicrobial and Antiproliferative Effects of CuO-TiO2-Chitosan-Escin Nanocomposites on Human Leukemic MOLT4 Cells.

Nanocomposites comprised of CuO-TiO2-chitosan-escin, which has adjustable physicochemical properties, provide a solution for therapeutic selectivity in cancer treatment. By controlling the intrinsic signaling primarily through the mitochondrial signaling pathway, we desired nanocomposites with enhanced anticancer activity by containing CuO-TiO2-chitosan-escin. The metal oxides CuO and TiO2, the natural polymer chitosan, and a phytochemical compound escin were combined to form CuO-TiO2-chitosan-escin nanocomposites. The synthesized nanocomposites were confirmed and characterized using FTIR spectroscopy, TEM, and UV-Vis absorption spectroscopy. A human leukemia cell line (MOLT-4) was used to assess the efficacy and selectivity of nanocomposites. Based on a cytotoxicity study, CuO-TiO2-chitosan-escin nanocomposites had inhibition concentrations (IC50) of 13.68, 8.9, and 7.14 µg/mL against human T lymphoblast cells after 24, 48, and 72 h of incubation, respectively. Compared with untreated MOLT-4 cells, CuO-TiO2-chitosan-escin nanocomposite-treated cells significantly increased (p < 0.05) caspase-3, -8, and -9 and decreased the levels of antioxidant enzymes GR, SOD, and GSH. Furthermore, MDA for lipid peroxidase and ROS levels significantly increased (p < 0.05) in the treated cells than in the untreated cells. Remarkably, CuO-TiO2-chitosan-escin nanocomposite-mediated control of cell cycles were mainly achieved through the activation of caspase-3, -8, and -9.

The Synthesis, Characterization and Applications of Polyhydroxyalkanoates (PHAs) and PHA-Based Nanoparticles.

Polyhydroxyalkanoates (PHAs) are storage granules found in bacteria that are essentially hydroxy fatty acid polyesters. PHA molecules appear in variety of structures, and amongst all types of PHAs, polyhydroxybutyrate (PHB) is used in versatile fields as it is a biodegradable, biocompatible, and ecologically safe thermoplastic. The unique physicochemical characteristics of these PHAs have made them applicable in nanotechnology, tissue engineering, and other biomedical applications. In this review, the optimization, extraction, and characterization of PHAs are described. Their production and application in nanotechnology are also portrayed in this review, and the precise and various production methods of PHA-based nanoparticles, such as emulsion solvent diffusion, nanoprecipitation, and dialysis are discussed. The characterization techniques such as UV-Vis, FTIR, SEM, Zeta Potential, and XRD are also elaborated.

Transient characteristics of universal cells on human-induced pluripotent stem cells and their differentiated cells derived from foetal stem cells with mixed donor sources.

INTRODUCTION: It is important to prepare 'hypoimmunogenic' or 'universal' human pluripotent stem cells (hPSCs) with gene-editing technology by knocking out or in immune-related genes, because only a few hypoimmunogenic or universal hPSC lines would be sufficient to store for their off-the-shelf use. However, these hypoimmunogenic or universal hPSCs prepared previously were all genetically edited, which makes laborious processes to check and evaluate no abnormal gene editing of hPSCs. METHODS: Universal human-induced pluripotent stem cells (hiPSCs) were generated without gene editing, which were reprogrammed from foetal stem cells (human amniotic fluid stem cells) with mixing 2-5 allogenic donors but not with single donor. We evaluated human leucocyte antigen (HLA)-expressing class Ia and class II of our hiPSCs and their differentiated cells into embryoid bodies, cardiomyocytes and mesenchymal stem cells. We further evaluated immunogenic response of transient universal hiPSCs with allogenic mononuclear cells from survival rate and cytokine production, which were generated by the cells due to immunogenic reactions. RESULTS: Our universal hiPSCs during passages 10-25 did not have immunogenic reaction from allogenic mononuclear cells even after differentiation into cardiomyocytes, embryoid bodies and mesenchymal stem cells. Furthermore, the cells including the differentiated cells did not express HLA class Ia and class II. Cardiomyocytes differentiated from transient universal hiPSCs at passage 21-22 survived and continued beating even after treatment with allogenic mononuclear cells.

Clinical trials in India: Where do we stand globally?

AIMS: To evaluate the trend of clinical trials in India over the last 4 years compared to the well-established countries using clinical trial registries since the advent of clinical trial registry of India (CTRI). MATERIALS AND METHODS: The data of clinical trials registered in India, United States (US), and European Union (EU) were obtained from websites of CTRI, clinicaltrial.gov and EU clinical trial registry, respectively from July 20, 2007 to August 29, 2011 for a period of 4 years. Trials registered in Australia, Canada, China, and Japan were obtained from WHO's international clinical trial registry platform for the same period. We used search words for the common diseases such as diabetes, hypertension, etc.. RESULTS: The total number of clinical trials registered during the study period was 67,448 across seven study nations. Clinical trials from India constituted only 2.7% of the total number of trials carried out, compared to US constituting 47% of the total number of trials registered, followed by 18% from EU and 11% from Japan. However, India, China, and Japan have been found to show an increase of 3.7%, 5.1%, and 13.1% increase in the number of trials registered in 2011 compared to 2007. In contrast, US and EU showed a decline of 11.3% and 11.95% respectively in the total number of trials registered in 2011 compared to 2007. CONCLUSIONS: Although India shows gradual increase in trials registered since the advent of CTRI, still it continues to lag behind established countries in clinical research.

The combined influence of substrate elasticity and surface-grafted molecules on the ex vivo expansion of hematopoietic stem and progenitor cells.

Umbilical cord blood (UCB) is an attractive source of hematopoietic stem and progenitor cells (HSPCs) for transplantation. However, the low number of HSPCs from a single UCB donor limits the direct transplantation of UCB to patients. Because little is known about the effects of the physical microenvironment on HSPC expansion, we investigated the ex vivo expansion of HSPCs cultured on biomaterials with different elasticities and grafted with different nanosegments. Polyvinylalcohol-co-itaconic acid (PVA-IA)-coated dishes with different stiffnesses ranging from a 3.7 kPa to 30.4 kPa storage modulus were used. Fibronectin or an oligopeptide (CS1, EILDVPST) was grafted onto the PVA-IA substrates. High ex vivo fold expansion of HSPCs was observed in the PVA-IA dishes grafted with fibronectin or CS1, which displayed an intermediate stiffness ranging from 12.2 kPa to 30.4 kPa. The fold expansion was more than 1.4 times higher than that cultured in tissue culture polystyrene dishes (TCPS, 12 GPa). Furthermore, HSPCs cultured in fibronectin or CS1-grafted PVA-IA-coated dishes with a stiffness of 12.2-30.4 kPa generated more pluripotent colony-forming units (CFU-GM and CFU-GEMM) than those in TCPS dishes. This result indicates that both the physical and biological properties of biomaterials affect the ex vivo expansion of HSPCs.

Primary tuberculous appendicitis presented with caecal perforation: a case report.

Gastrointestinal tuberculosis accounts for 3% of the extrapulmonary tuberculosis with ileocaecal region being the common site of involvement up to 75%. Primary involvement of appendix is very rare and accounts for only 0.6% to 2.9% of gastrointestinal tuberculosis in the absence tubercular focus elsewhere. The pre-operative investigations usually give non-specific results. The diagnosis in most instances made only after histopathology. Here we report a case of primary appendicular tuberculosis in a patient presented with caecal perforation.

Postoperative hypertension following radical neck dissection.

Baroreflex failure results in wide excursions of blood pressure and heart rate. We report two cases that developed severe postoperative hypertension after radical neck dissection. Carotid sinus denervation during neck dissection may be the cause of the reflex hypertension once general anesthesia-induced vasodilatation has ended.