Size discrimination of colloidal nanoparticles by thiol-functionalized MCM-41 mesoporous molecular sieves

Thiol-functionalized MCM-41 mesoporous materials with a well-defined pore size of 40 Å may be used to discriminate between colloidal gold and silver particles in a mixture. More specifically, the thiol-functionalized MCM-41 material selectively entraps colloidal gold particles (size 35 Å) in the pores from a mixture of the gold and silver particles of size 70 Å. The gold particles are held in the matrix via thiolate linkages and this process has been studied using UV-vis spectroscopy and thermogravimetry/differential thermal analysis. This approach is promising for application in bioseparation methodologies as well as in the generation of one-dimensional superstructure assemblies

Entrapment and catalytic activity of gold nanoparticles in amine-functionalized MCM-41 matrices synthesized by spontaneous reduction of aqueous chloroaurate ions

There is tremendous current interest in the generation of nano-hybrid materials using silicate mesoporous materials. We describe herein a new process for the synthesis of gold nanoparticle-amine functionalized MCM-41 hybrid materials by the spontaneous reduction of chloroaurate ions within the silicate matrix. The gold nanoparticles thus formed are bound to the pores of the MCM-41 framework by amine functional groups and show excellent catalytic activity in hydrogenation reactions

Inorganic phosphate nanorods are a novel fluorescent label in cell biology

We report the first use of inorganic fluorescent lanthanide (europium and terbium) ortho phosphate [LnPO(4)·H(2)O, Ln = Eu and Tb] nanorods as a novel fluorescent label in cell biology. These nanorods, synthesized by the microwave technique, retain their fluorescent properties after internalization into human umbilical vein endothelial cells (HUVEC), 786-O cells, or renal carcinoma cells (RCC). The cellular internalization of these nanorods and their fluorescence properties were characterized by fluorescence spectroscopy (FS), differential interference contrast (DIC) microscopy, confocal microscopy, and transmission electron microscopy (TEM). At concentrations up to 50 μg/ml, the use of [(3)H]-thymidine incorporation assays, apoptosis assays (TUNEL), and trypan blue exclusion illustrated the non-toxic nature of these nanorods, a major advantage over traditional organic dye

Intracellular gold nanoparticles enhance non-invasive radiofrequency thermal destruction of human gastrointestinal cancer cells

<p>Abstract</p> <p>Background</p> <p>Novel approaches to treat human cancer that are effective with minimal toxicity profiles are needed. We evaluated gold nanoparticles (GNPs) in human hepatocellular and pancreatic cancer cells to determine: 1) absence of intrinsic cytotoxicity of the GNPs and 2) external radiofrequency (RF) field-induced heating of intracellular GNPs to produce thermal destruction of malignant cells. GNPs (5 nm diameter) were added to 2 human cancer cell lines (Panc-1, Hep3B). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and propidium iodide-fluorescence associated cell sorting (PI-FACS) assessed cell proliferation and GNP-related cytotoxicity. Other GNP-treated cells were exposed to a 13.56 MHz RF field for 1, 2, or 5 minutes, and then incubated for 24 hours. PI-FACS measured RF-induced cytotoxicity.</p> <p>Results</p> <p>GNPs had no impact on cellular proliferation by MTT assay. PI-FACS confirmed that GNPs alone produced no cytotoxicity. A GNP dose-dependent RF-induced cytotoxicity was observed. For Hep3B cells treated with a 67 μM/L dose of GNPs, cytotoxicity at 1, 2 and 5 minutes of RF was 99.0%, 98.5%, and 99.8%. For Panc-1 cells treated at the 67 μM/L dose, cytotoxicity at 1, 2, and 5 minutes of RF was 98.5%, 98.7%, and 96.5%. Lower doses of GNPs were associated with significantly lower rates of RF-induced thermal cytotoxicity for each cell line (P < 0.01). Cells not treated with GNPs but treated with RF for identical time-points had less cytotoxicity (Hep3B: 17.6%, 21%, and 75%; Panc-1: 15.3%, 26.4%, and 39.8%, all P < 0.01).</p> <p>Conclusion</p> <p>We demonstrate that GNPs 1) have no intrinsic cytotoxicity or anti-proliferative effects in two human cancer cell lines <it>in vitro </it>and 2) GNPs release heat in a focused external RF field. This RF-induced heat release is lethal to cancer cells bearing intracellular GNPs <it>in vitro</it>.</p

Hydrochemical Evaluation of Water Quality and Trophic State Status of Saheb Bandh Lake, Purulia

Saheb bandh lake is an important wetland ecosystem of Purulia district and is well known for its biological diversity, aesthetic beauty, recreation and multipurpose features. In the present study an attempt is made to evaluate water quality as well as trophic state status of the lake. Lake water is mostly of Mg-HCO3 type. Relationship between different ionic ratios indicates that weathering of silicate minerals is generally considered to be the major source of alkalis in the lake water. Regarding drinking and irrigation water suitability criteria all the samples are moderately suitable. According to United States Salinity Laboratory (USSL) classifications lake water falls in medium salinity – low sodium category. Trophic State Index (TSI) indicates that the eutrophic nature exhibit in this lake.  The ratio of total nitrogen and total phosphorus reflects that the lake is phosphorus dominant in respect of nutrient.

Nano-ablative immunotherapy for cancer treatment

Immunotherapy has provided a new avenue to treat metastatic cancers, which result in ∼90% of cancer related deaths. However, current immunotherapies, such as immune checkpoint therapy (ICT), have met with limited success, primarily due to tumor intrinsic and extrinsic factors that inhibit antitumor immune responses. To overcome the immune suppression of the tumor microenvironment (TME) and enhance the tumoricidal activity of ICT, phototherapy, particularly photothermal therapy (PTT), combined with nanomedicine has become a viable option. PTT disrupts target tumor homeostasis, releasing tumor associated antigens (TAAs), tumor specific antigens (TSAs), danger associated molecular patterns (DAMPs), and scarce nutrients required to “feed” activated antitumor immune cells. While nanoparticles localize and specify the phototherapeutic effect, they can also be loaded with immune stimulants, TME modulators, and/or chemotherapeutic agents to greatly enhance immune stimulation and tumor killing. Combining these three technologies, which we term nano-ablative immunotherapy (NAIT), with ICT can greatly enhance their therapeutic effects. In this review, we will discuss the successes and limitations of NAIT + ICT. Specifically, we will discuss how the TME limits tumoricidal activity and what should be considered to overcome these limitations.This work was supported in part by grants R01CA205348 from the National Cancer Institution (doi.org/10.13039/100008569) and HR16-085 and HF20-019 from the Oklahoma Center for the Advancement of Science and Technology (doi.org/10.13039/100008569). Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Potential therapeutic application of gold nanoparticles in B-chronic lymphocytic leukemia (BCLL): enhancing apoptosis

B-Chronic Lymphocytic Leukemia (CLL) is an incurable disease predominantly characterized by apoptosis resistance. We have previously described a VEGF signaling pathway that generates apoptosis resistance in CLL B cells. We found induction of significantly more apoptosis in CLL B cells by co-culture with an anti-VEGF antibody. To increase the efficacy of these agents in CLL therapy we have focused on the use of gold nanoparticles (GNP). Gold nanoparticles were chosen based on their biocompatibility, very high surface area, ease of characterization and surface functionalization. We attached VEGF antibody (AbVF) to the gold nanoparticles and determined their ability to kill CLL B cells. Gold nanoparticles and their nanoconjugates were characterized using UV-Visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). All the patient samples studied (N = 7) responded to the gold-AbVF treatment with a dose dependent apoptosis of CLL B cells. The induction of apoptosis with gold-AbVF was significantly higher than the CLL cells exposed to only AbVF or GNP. The gold-AbVF treated cells showed significant down regulation of anti-apoptotic proteins and exhibited PARP cleavage. Gold-AbVF treated and GNP treated cells showed internalization of the nanoparticles in early and late endosomes and in multivesicular bodies. Non-coated gold nanoparticles alone were able to induce some levels of apoptosis in CLL B cells. This paper opens up new opportunities in the treatment of CLL-B using gold nanoparticles and integrates nanoscience with therapy in CLL. In future, potential opportunities exist to harness the optoelectronic properties of gold nanoparticles in the treatment of CLL

Designing Nanoconjugates to Effectively Target Pancreatic Cancer Cells In Vitro and In Vivo

Pancreatic cancer is the fourth leading cause of cancer related deaths in America. Monoclonal antibodies are a viable treatment option for inhibiting cancer growth. Tumor specific drug delivery could be achieved utilizing these monoclonal antibodies as targeting agents. This type of designer therapeutic is evolving and with the use of gold nanoparticles it is a promising approach to selectively deliver chemotherapeutics to malignant cells. Gold nanoparticles (GNPs) are showing extreme promise in current medicinal research. GNPs have been shown to non-invasively kill tumor cells by hyperthermia using radiofrequency. They have also been implemented as early detection agents due to their unique X-ray contrast properties; success was revealed with clear delineation of blood capillaries in a preclinical model by CT (computer tomography). The fundamental parameters for intelligent design of nanoconjugates are on the forefront. The goal of this study is to define the necessary design parameters to successfully target pancreatic cancer cells.The nanoconjugates described in this study were characterized with various physico-chemical techniques. We demonstrate that the number of cetuximab molecules (targeting agent) on a GNP, the hydrodynamic size of the nanoconjugates, available reactive surface area and the ability of the nanoconjugates to sequester EGFR (epidermal growth factor receptor), all play critical roles in effectively targeting tumor cells in vitro and in vivo in an orthotopic model of pancreatic cancer.Our results suggest the specific targeting of tumor cells depends on a number of crucial components 1) targeting agent to nanoparticle ratio 2) availability of reactive surface area on the nanoparticle 3) ability of the nanoconjugate to bind the target and 4) hydrodynamic diameter of the nanoconjugate. We believe this study will help define the design parameters for formulating better strategies for specifically targeting tumors with nanoparticle conjugates

Modulating Pharmacokinetics, Tumor Uptake and Biodistribution by Engineered Nanoparticles

Inorganic nanoparticles provide promising tools for biomedical applications including detection, diagnosis and therapy. While surface properties such as charge are expected to play an important role in their in vivo behavior, very little is known how the surface chemistry of nanoparticles influences their pharmacokinetics, tumor uptake, and biodistribution.Using a family of structurally homologous nanoparticles we have investigated how pharmacological properties including tumor uptake and biodistribution are influenced by surface charge using neutral (TEGOH), zwitterionic (Tzwit), negative (TCOOH) and positive (TTMA) nanoparticles. Nanoparticles were injected into mice (normal and athymic) either in the tail vein or into the peritoneum.Neutral and zwitterionic nanoparticles demonstrated longer circulation time via both i.p. and i.v. administration, whereas negatively and positively charged nanoparticles possessed relatively short half-lives. These pharmacological characteristics were reflected on the tumor uptake and biodistribution of the respective nanoparticles, with enhanced tumor uptake by neutral and zwitterionic nanoparticles via passive targeting