Raman excitation profiles of actinomycin-DNA complex

Label-Free Monitoring of Drug-Induced Cytotoxicity and Its Molecular Fingerprint by Live-Cell Raman and Autofluorescence Imaging

Simultaneous observation of drug distribution at the effector site and subsequent cell response are essential in the drug development process. However, few studies have visualized the drug itself and biomolecular interactions in living cells. Here, we used label-free Raman microscopy to investigate drug-induced cytotoxicity and visualize drug uptake and subcellular localization by its specific molecular fingerprint. A redox-sensitive Raman microscope detected the decrease of reduced cytochrome c (cyt c) after Actinomycin D (ActD) treatment in a time-dependent and dose-dependent format. Immunofluorescence staining of cyt c suggested that the release of cyt c was not the major cause. Combining Raman microscopy with conventional biological methods, we reported that the oxidization of cyt c is an early cytotoxicity marker prior to the release of cyt c. Moreover, as the spectral properties of ActD are sensitive to the surrounding environment, subcellular localization of ActD was visualized sensitively by the weak autofluorescence, and the intercalation of ActD into DNA was detected by shifted Raman peaks, allowing for parallel observation of drug uptake and the mechanism of action. In this research, we achieved simultaneous observation of cytotoxicity and cellular drug uptake by Raman microscopy, which could facilitate a precise understanding of pharmacological effects and predict potential drug toxicity in the future.

One pot synthesis of doxorubicin loaded gold nanoparticles for sustained drug release

Here, we report a facile, versatile and simple one-pot synthesis of doxorubicin (Dox) loaded gold nanoparticles (Dox–GNP conjugate), where Dox can act both as a reducing as well as a capping agent.

Actinomycins like anti-cancer photo-sensitizers

Spectroscopic and microscopic study on application of actinomycins as anti-tumor photo-sensitizing drugs was carried out in this work. It has been shown that 7-aminoactinomycin (7AAMD) and actinomycin D (AMD) inside cells of line HeLa bind not only with DNA, but also with proteins. Fluorescence of 7AAMD in HeLa cells and destruction of these cells by photosensitizing with actinomycin D were detected. When photo-destruction occurs, the antibiotic is released out from destroyed cells.