title: Click chemistry approach for imaging intracellular and intratissue distribution of curcumin and its nanoscale carrier.
abstract: This study was aimed at developing a fluorescence imaging approach to simultaneously characterize the delivery and distribution of a bioactive molecule, curcumin, and its micelle based nanoscale carrier in cells and tissue models. To enable imaging of curcumin, a monoalkyne derivative of curcumin was synthesized and purified using LC-MS. Intracellular uptake of curcumin was characterized using a click chemistry reaction between a monoalkyne modified curcumin and Alexa-488 azide fluorescent dye in cells and tissues. Fluorescence images of cells and tissues incubated with monoalkyne curcumin showed specific detection of intracellular delivered monoalkyne curcumin using the click chemistry reaction. The fluorescence imaging results also demonstrated significant improvement in detection sensitivity of intracellular delivered curcumin as compared to measurements based on native fluorescence of unmodified curcumin. Intracellular uptake of monoalkyne curcumin was characterized as a function of incubation time and concentration. The results show a rapid uptake of monoalkyne curcumin during the first 4 h of incubation. Modification of curcumin to its monoalkyne derivative did not impact its apoptotic activity in cancer cells. DSPE-PEG micelles labeled with Alexa-647 were selected as a representative nanoscale carrier to enhance the solubility and delivery of monoalkyne curcumin. Fluorescence images of cells and tissues incubated with fluorescently labeled micelles containing monoalkyne curcumin clearly illustrate significant differences in intracellular and intratissue localization of DSPE-PEG and encapsulated monoalkyne curcumin. The imaging approach developed in this study can be used to understand delivery and distribution of diverse bioactive compounds and their nanocarrier systems as well as in situ measurement of interactions of bioactives with cellular and tissue targets.
authors: Department of Biological Engineering and ‡Department of Food Science and Technology, University of California-Davis , Davis, California 95616, United States.
authors: Zhen
authors: Z
authors: Luo
authors: Rohan V
authors: RV
authors: Tikekar
authors: Nitin
authors: N
authors: Nitin
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D057930:Click Chemistry; D003474:Curcumin / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D006834:Hydrazines / Q000737:chemistry; D008823:Micelles; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012995:Solubility; D013329:Structure-Activity Relationship; D013499:Surface Properties; D014407:Tumor Cells, Cultured
chemical_list: C417561:Alexa 488 hydrazide; D000970:Antineoplastic Agents; D005456:Fluorescent Dyes; D006834:Hydrazines; D008823:Micelles; D003474:Curcumin