A Novel Fluorescent Quantum Dot Probe for the Rapid Diagnostic High Contrast Imaging of Tumor in Mice.

A simple probe - antibody conjugated silica over coated cadmium selenide quantum dots (QD-Ab probe) for efficient and rapid diagnostic in vivo imaging of tumors is developed. Compared to unconjugated quantum dots (QD), these probes underwent efficient cellular internalization and tumor targeting behavior, retaining bright emission under in vivo cancer models. Silica over coated cadmium selenide quantum dots were conjugated with Epidermal growth factor receptor (EGFR) monoclonal antibody to detect the over expression of EGFR in cancer models. The in vitro cellular internalization efficiency of QD and QD-Ab probe in cultured stem cells (RADMSCs) and cancer cells (HeLa) were assessed by ICP-OES and cLSM. Results demonstrated a greater internalization efficiency of CdSe-Silica QD-Ab probe than CdSe-Silica QDs. For in vivo imaging solid tumor bearing mice was subjected to tail vein injection of QD and QD-Ab probe. After the specific time interval of injection, mice were anesthetized and subjected into Xenogen IVIS®200 imaging system, followed by ex vivo imaging. Subsequently, ultrathin sections of tumor were imaged by using cLSM. Both in vivo and ex vivo imaging results confirmed the tumor-targeted imaging efficiency of QD-Ab probes compared to unconjugated QDs.

Embelin (2,5-dihydroxy-3-undecyl-p-benzoquinone): a bioactive molecule isolated from Embelia ribes as an effective photodynamic therapeutic candidate against tumor in vivo.

The present study was carried out to assess the photosensitizing potential of embelin, the biologically active natural product isolated from Embelia ribes in photodynamic therapy (PDT) experiments in vivo. In vitro PDT clearly indicated that embelin recorded significant cytotoxicity in Ehrlich's Ascites Carcinoma (EAC) cells, which is superior to 5-aminolevulinic acid, a known photodynamic compound. For in vivo experiments solid tumor was induced using EAC cells in the male Swiss albino mice of groups I, II, III and IV. Group I served as the control (without solid tumor), group II served as tumor bearing mice without treatment and groups III and IV served as treatments. At the completion of 4 weeks of induction, the tumor bearing mice from group III and IV were given an intraperitoneal injection with embelin (12.5mg/kg body weight). After 24h, tumor area in the Group III and IV animals was exposed to visible light from a 1,000 W halogen lamp. The mice from groups I to III were sacrificed 2 weeks after the PDT treatment and the marker enzymes (myeloperoxidase [MPO], ß-d-glucuronidase, and rhodanese) were assayed and expression of Bcl-2 and Bax were analyzed in normal and tumor tissues. Animals from group IV were sacrificed after 90 days of PDT treatment and the above mentioned parameters were recorded. Reduction in tumor volume and reversal of biochemical markers to near normal levels were observed in the treated groups. This is the first report on PDT using a natural compound for solid tumor control in vivo. The uniqueness of the mode of treatment lies in the selective uptake of the nontoxic natural compound, embelin from the medicinal plant E. ribes used in Indian system of medicine, by the solid tumor cells and their selective destruction using PDT without affecting the neighboring normal cells, which is much advantageous over radiation therapy now frequently used.

Therapeutic effect of Broussonetia papyrifera and Lonicera japonica in ovalbumin-induced murine asthma model.

Broussonetia papyrifera (L.) Vent. and Lonicera japonica Thunb. have been used in recent medicinal research for their antioxidative and anti-inflammatory properties. The present study investigated the therapeutic efficacy of B. papyrifera and L. japonica ethanolic extracts in a murine model of ovalbumin-induced asthma, in which intra-peritoneal (IP) injections and aerosol ovalbumin delivery were used to induce allergic asthma. Bronchioalveolar lavage fluid (BALF), serum samples, lungs and livers were collected from the experimental groups. In the groups treated with B. papyrifera and L. japonica extracts, CD3, CD4, serum IgE and IL-4 levels; activities of matrix metalloproteinase (MMP)-2 and MMP-9; and eotaxin levels in the BALF significantly decreased to near normal levels. Results of a histopathological analysis showed that the level of inflammation and mucous secretions reduced in the treated groups compared to the corresponding levels in the other groups. Moreover, results of a serum enzymatic analysis showed the non-toxic nature of the extracts in the B. papyrifera and L. japonica treated groups. Taken together, these results clearly indicate that the B. papyrifera and L. japonica extracts may be very effective against asthma and inflammation related diseases.

Selective photothermal efficiency of citrate capped gold nanoparticles for destruction of cancer cells.

Gold nanoparticles are recently having much attention because of their increased applications in biomedical fields. In this paper, we demonstrated the photothermal efficacy of citrate capped gold nanoparticles (AuNPs) for the destruction of A431 cancer cells. Citrate capped AuNPs were synthesized successfully and characterized by UV-visible-NIR spectrophotometry and High Resolution Transmission Electron Microscopy (HR-TEM). Further, AuNPs were conjugated with epidermal growth factor receptor antibody (anti-EGFR) and applied for the selective photothermal therapy (PTT) of human epithelial cancer cells, A431. PTT experiments were conducted in four groups, Group I--control cells, Group II--cells treated with laser light alone, Group III--cells treated with unconjugated AuNP and further laser irradiation and Group IV--anti-EGFR conjugated AuNP treated cells irradiated by laser light. After laser irradiation, cell morphology changes that were examined using phase contrast microscopy along with the relevant biochemical parameters like lactate dehydrogenase activity, reactive oxygen species generation and caspase-3 activity were studied for all the groups to determine whether cell death occurs due to necrosis or apoptosis. From these results we concluded that, these immunotargeted nanoparticles could selectively induce cell death via ROS mediated apoptosis when cells were exposed to a low power laser light.

Cellular uptake and subcellular localization of highly luminescent silica-coated CdSe quantum dots--in vitro and in vivo.

With excellent optical properties, quantum dots (QDs) have been made as attractive molecular probes for labeling cells in biological research. The purpose of the present work is to explore the possible role of silica-coated cadmium selenide (CdSe) QDs in the in vitro and in vivo cellular uptake and their subcellular localization. The in vitro uptake characteristics of silica-coated CdSe QDs were performed in cultured New Zealand rabbit adipose tissue-derived mesenchymal stem cells (RADMSCs) and Human cervical cancer cells (HeLa) using fluorescence microscopy after staining with 4,6-diamidino-2-phenylindole (DAPI). The in vitro results showed that the silica-coated CdSe QDs were efficiently taken up by the cells and it was localized in the intracellular vesicles giving strong fluorescence from the cytoplasm and nearby nucleus. Subsequently, the in vivo localization and distribution of QDs were studied by the hematoxilin stained semithin cryosections of tissues (~15 µm thickness) under fluorescence microscopy and ultrathin sections of tissues (~100 nm thickness) under confocal laser scanning microscopy at the distribution maxima. Our in vivo results confirmed the effective cellular uptake and even distribution pattern of QDs in tissues. Overall, these in vitro and in vivo results are represented with focus on internalization, subcellular localization and distribution of the QDs, in view of their potential applications in biomedical field.

Fluorescence imaging of stem cells, cancer cells and semi-thin sections of tissues using silica-coated CdSe quantum dots.

Trioctylphosphine oxide capped cadmium selenide quantum dots, synthesized in organic media were rendered water soluble by silica overcoating. Silanisation was done by a simple reverse microemulsion method using aminopropyl silane as the silica precursor. Further, the strong photoluminescence of the silica-coated CdSe quantum dots has been utilized to visualize rabbit adipose tissue-derived mesenchymal stem cells (RADMSCs) and Daltons lymphoma ascites (DLA) cancerous cells in vitro. Subsequently the in vivo fluorescence behaviours of QDs in the tissues were also demonstrated by intravenous administration of the QDs in Swiss albino mice. The fluorescence microscopic images in the stem cells, cancer cells and semi-thin sections of mice organs proved the strong luminescence property of silica-coated quantum dots under biological systems. These results establish silica-coated CdSe QDs as extremely useful tools for molecular imaging and cell tracking to study the cell division and metastasis of cancer and other diseases.

Biokinetics and in vivo distribution behaviours of silica-coated cadmium selenide quantum dots.

Recently, quantum dots derived from trace elements like cadmium and selenium have attracted widespread interest in biology and medicine. They are rapidly being used as novel tools for both diagnostic and therapeutic purposes. In this report, we evaluated the distribution of silica-coated cadmium selenide (CdSe) quantum dots (QDs) following intravenous injection into male Swiss albino mice as a model system for determining tissue localization using in vivo fluorescence and ex vivo elemental analysis by inductively coupled plasma optical emission spectroscopy (ICP-OES). Trioctylphosphine oxide-capped CdSe quantum dots were synthesized and rendered water soluble by overcoating with silica, using aminopropyl silane (APS) as silica precursor. ICP-OES was used to measure the cadmium content to indicate the concentration of QDs in blood, organs and excretion samples collected at predetermined time intervals. Meanwhile, the distribution and aggregation state of QDs in tissues were also investigated in cryosections of the organs by fluorescence microscopy. We have demonstrated that the liver and kidney were the main target organs for QDs. Our systematic investigation clearly shows that most of the QDs were metabolized in the liver and excreted via faeces and urine in vivo. A fraction of free QDs, maintaining their original form, could be filtered by glomerular capillaries and excreted via urine as small molecules within 5 days.

Broccoli regulates protein alterations and cataractogenesis in selenite models.

PURPOSE: To study the efficacy of Brassica oleracea var. italica (Broccoli) in the prevention of selenite induced biochemical changes and the incidence of cataractogenesis in vivo. METHODS: Eight day old Sprague-Dawley rat pups were divided into four groups: I-Control; II-Sodium selenite (4 mg/kg body weight) administered; III-Sodium selenite + quercetin; and IV-Sodium selenite + flavonoid fraction of broccoli (FFB). Treatment groups III and IV received quercetin and FFB intraperitoneally from 8th to 15th day at a concentration (2.0 mg/kg body weight). The development of cataract was assessed and graded by slit-lamp examination. Some relevant biochemical parameters-such as activities of superoxide dismutase (SOD), catalase, Ca(2+)ATPase, calpains, concentration of reduced glutathione (GSH), levels of calcium, lipid peroxidation product-thiobarbituric acid reacting substances (TBARS) and SDS-PAGE analysis of lens water soluble proteins (WSF) were analyzed. RESULTS: FFB modulates selenite-induced biochemical changes in albino rats. Lenses of Group I rats were clear but in Group II, all lenses developed dense opacification (grade 5 and 6), whereas mild opacifications were observed in Group III and Group IV (grade 2). Group III and Group IV lenses exhibited significantly higher values of antioxidant enzymes, Ca(2+)ATPase, and GSH, whereas lower values were obtained for TBARS, calcium, and calpains compared to Group II. Lens protein profile of water soluble proteins showed normal levels of Group III and Group IV compared to Group II lenses. CONCLUSION: FFB prevents selenite-induced cataractogenesis in albino rat pups, possibly by maintaining antioxidant status and ionic balance through Ca(2+) ATPase pump, inhibition of lipid peroxidation, calpain activation, and protein insolubilization, which have been reported in this article for the first time.