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In this investigation, quantum dots of cadmium sulfide semiconductor crystals capped with dextrin and bioconjugated with doxorubicin were used to target and provide imaging of HeLa cells, which play a critical role in cervical cancer. These dextrin-capped cadmium sulfide nanoparticles/semiconductor quantum dots bioconjugated with doxorubicin are in the range of 5 nm in size and exhibit an intense fluorescence emission in the green and red spectrum, which benefited fluorescence imaging on HeLa cells. Results obtained showed that dextrin-capped cadmium sulfide nanoparticles/semiconductor quantum dots bioconjugated with doxorubicin have a large accumulation time in cells distributed in the cytoplasm and nucleus, where the pharmacological effects of drugs are enhanced. Cells treated with dextrin-capped cadmium sulfide nanoparticles/semiconductor quantum dots bioconjugated with doxorubicin also showed a major increase in size, including cytoplasm and nucleus, as compared to cells treated with doxorubicin alone. Additionally, binucleated cells and membrane blebbing was also found. Therefore, dextrin-capped cadmium sulfide nanoparticles/semiconductor quantum dots bioconjugated with doxorubicin could be used as probes for simultaneous cell cancer-targeted fluorescent imaging, tracking and monitoring cell viability with the advantage of improving the clinical effects of antineoplastic drugs with increasing apoptosis. [ABSTRACT FROM AUTHOR]

Abstract: Contagious ecthyma virus (CEV) is a disease caused by a parapoxvirus, also is a potent genetic carrier with the capacity for regulating apoptosis in the cells of infected skin, a mechanism that serves for evading the immune response of the host. It has been suggested that the virus may remain in the skin and be able to cause repeated infections in the same flock. The effect of infection as well as the presence of contagious ecthyma virus was evaluated in terms of lesions and apoptosis in the skin of animals, infected both naturally and experimentally. Samples used were obtained from a naturally infected sheep, 5 goats inoculated with CEV and a negative control. Samples obtained were longitudinally sectioned and processed using photon and electron microscopy, and embedded in paraffin and araldite. Samples embedded in paraffin were sectioned in 5μm of thickness and dyed with orange eosin–hematoxilin G and Gomori''s trichrom stain, apoptosis was demonstrated by the TUNEL assay, the viral antigen was revealed using polyclonal antibodies, and the presence of lymphocytes CD4+ and CD8+, with monoclonal antibodies. The samples processed in resin were cut to obtain semi-fine sections and dyed with toluidine blue-borax, and the ultra-fine sections were impregnated with lead citrate and uranyl acetate. Observations were similar in both, the natural infected animal and the experimental group. Infiltration was observed as well as images suggestive of a process of apoptosis. The TUNEL assay demonstrated that the number of epithelial cells undergoing apoptosis diminished during the process and increased among defense cells, until they almost disappeared at the beginning of healing. Cells undergoing apoptosis were located near the sebaceous glands and pilose follicles. The infiltrated lymphocytes gradually diminished. The viral antigen was observed in cells with morphology suggestive of apoptosis, located in sebaceous glands and pilose follicles. Using electron microscopy, cells with morphology compatible with that of lymphocytes were observed to be undergoing apoptosis, but there was little evidence of viral particles. [Copyright &y& Elsevier]