Toxicity of CdSe Nanoparticles in Caco-2 Cell Cultures

<p>Abstract</p> <p>Background</p> <p>Potential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied.</p> <p>Results</p> <p>Commercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment were studied after 24 hours of incubation. It was found that cytotoxicity of CdSe QDs was modulated by surface coating, as PEG coated CdSe QDs had less of an effect on Caco-2 cell viability and attachment. Acid treatment increased the toxicity of PEG coated QDs, most likely due to damage or removal of the surface coating and exposure of CdSe core material. Incubation with un-dialyzed in-house prepared CdSe QD preparations, which contained an excess amount of free Cd²⁺, resulted in dramatically reduced cell viability.</p> <p>Conclusion</p> <p>Exposure to CdSe QDs resulted in cultured intestinal cell detachment and death; cytotoxicity depended largely, however, on the QD coating and treatment (e.g. acid treatment, dialysis). Experimental results generally indicated that Caco-2 cell viability correlated with concentration of free Cd²⁺ions present in cell culture medium. Exposure to low (gastric) pH affected cytotoxicity of CdSe QDs, indicating that route of exposure may be an important factor in QD cytotoxicity.</p

Toxicity of CdSe Nanoparticles in Caco-2 Cell Cultures

<p>Abstract</p> <p>Background</p> <p>Potential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied.</p> <p>Results</p> <p>Commercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment were studied after 24 hours of incubation. It was found that cytotoxicity of CdSe QDs was modulated by surface coating, as PEG coated CdSe QDs had less of an effect on Caco-2 cell viability and attachment. Acid treatment increased the toxicity of PEG coated QDs, most likely due to damage or removal of the surface coating and exposure of CdSe core material. Incubation with un-dialyzed in-house prepared CdSe QD preparations, which contained an excess amount of free Cd²⁺, resulted in dramatically reduced cell viability.</p> <p>Conclusion</p> <p>Exposure to CdSe QDs resulted in cultured intestinal cell detachment and death; cytotoxicity depended largely, however, on the QD coating and treatment (e.g. acid treatment, dialysis). Experimental results generally indicated that Caco-2 cell viability correlated with concentration of free Cd²⁺ions present in cell culture medium. Exposure to low (gastric) pH affected cytotoxicity of CdSe QDs, indicating that route of exposure may be an important factor in QD cytotoxicity.</p

FORMULATION, CHARACTERIZATION AND EVALUATION OF ANTI-INFLAMMATORY AND ANTI-ANGIOGENIC ACTIVITIES OF MEMECYLAENE NANOEMULSION

The present study was undertaken to formulate and evaluate the anti-inflammatory, anti-oxidant and anti-angiogenic activities of nanoemulsion of Memecylaene.&nbsp; Memecylaene was isolated from the leaves of Memecylon malabaricum by using various chromatographic methods. An oil-in-water (O/W) nanoemulsion of Memecylaene was formulated by sonication method using sunflower oil (oil phase), Tween 80 (Surfactant) and Ethanol (co-surfactant). The prepared nanoemulsion was characterized for its droplet size, poly dispersity index and zeta potential. Stability studies were performed and the nanoemulsions were subjected to different biological activities. The formulated nanoemulsion had a particle size range of 52.02 nm to 59.47 nm and zeta potential of -1.27 mV. The enhanced activity of Memecylaene, encapsulated in O/W emulsions is evidenced by the inhibition of phospholipase (PLA2) enzyme and H+, K+ -ATPase and thus showing anti-inflammatory and anti-secretagogues effects. The in vitro anti-oxidant activity was evaluated by DPPH radical and Nitric oxide radical scavenging activity. Further, the inhibition of the growth of neo vessels formation in the in-vivo model system of chick chorioallantoic membrane (CAM) assay, which is angiogenesis dependent, was also observed. The above findings would help in understanding the putative potential of Memecylaene-loaded nanoemulsion as a therapeutic agent. Keywords: Anti-angiogenesis, Anti-oxidant, Gastric (H+ K+), Memecylaene, Nanoemulsion, Phospholipase A2 (PLA2)

In Vitro Evaluation of Theranostic Polymeric Micelles for Imaging and Drug Delivery in Cancer

<p>For the past decade engineered nanoplatforms have seen a momentous progress in developing a multimodal theranostic formulation which can be simultaneously used for imaging and therapy. In this report we describe the synthesis and application of theranostic phospholipid based polymeric micelles for optical fluorescence imaging and controlled drug delivery. CdSe quantum dots (QDs) and anti-cancer drug, doxorubicin (Dox), were co-encapsulated into the hydrophobic core of the micelles. The micelles are characterized using optical spectroscopy for characteristic absorbance and fluorescence features of QDs and Dox. TEM and DLS studies yielded a size of &#60;50 nm for the micellar formulations with very narrow size distribution. A sustained release of the drug was observed from the co-encapsulated micellar formulation. In vitro optical fluorescence imaging and cytotoxicity studies with HeLa cell line demonstrated the potential of these micellar systems as efficient optical imaging and therapeutic probes.</p