Super-sensitive bifunctional nanoprobe: Self-assembly of peptide-driven nanoparticles demonstrating tumor fluorescence imaging and therapy

The development of nanomedicine has recently achieved several breakthroughs in the field of cancer treatment; however, biocompatibility and targeted penetration of these nanomaterials remain as limitations, which lead to serious side effects and significantly narrow the scope of their application. The self-assembly of intermediate filaments with arginine-glycine-aspartate (RGD) peptide (RGD-IFP) was triggered by the hydrophobic cationic molecule 7-amino actinomycin D (7-AAD) to synthesize a bifunctional nanoparticle that could serve as a fluorescent imaging probe to visualize tumor treatment. The designed RGD-IFP peptide possessed the ability to encapsulate 7-AAD molecules through the formation of hydrogen bonds and hydrophobic interactions by a one-step method. This fluorescent nanoprobe with RGD peptide could be targeted for delivery into tumor cells and released in acidic environments such as endosomes/lysosomes, ultimately inducing cytotoxicity by arresting tumor cell cycling with inserted DNA. It is noteworthy that the RGD-IFP/7-AAD nanoprobe tail-vein injection approach demonstrated not only high tumor-targeted imaging potential, but also potent antitumor therapeutic effects in vivo. The proposed strategy may be used in peptide-driven bifunctional nanoparticles for precise imaging and cancer therapy.

Simultaneous Three Color Detection of Surface Antigen (My 7), Intracellular Antigen (c-myc), and DNA Content using Single Laser Flow Cytometry / 대한산부인과학회잡지

Flow cytometry, a useful tool for measuring DNA content and cell differentiation as expressed by cell surface markers, is utilized to measure multiple antigens, especially surface antigen, intracellular oncoprotein, and DNA content, simultaneously. For this simultaneous detection, several methods off ixation and permeabilization have been used with limited values. In this study, 20 ng/ml of lysolecithin in 1% paraformaldehyde solution was utilized for fixation and permeabilization of cultured promyelocytic leukemic cells(HL 60). The cells were first stained with phycoerythrin (PE)-conjugated monoclonal antibody to the cell surface My 7 antigen and then were fixed and permeabilized with 20 ng/ml of lysolecithin in 1% partormaldehyde solution. After incubation, the fixed and permeabilized cells were stained with monoclonal antibody to intracellular c-myc antigen, which were followed by fluorescein isothiocyanate (FITC)-conjugated secondary antibody. The c-myc stained cells were finally stained for DNA content with 7-amino-actinomycin D(7-AAD). This procedure permits excellent staining for intracellular oncoproteins and preservation of surface antigens with relatively low cofficients of variation (CV) for the G0G1 peak of the DNA histograms and suggests that the sequential staining procedure of surface antigen, intracellular antigen, and DNA content will be extended for the study of correlations with cellular differentiation, expression of oncoproteins, and cell cycle analysis in the cells which are obtained from human malignant diseases using a 488 nm single laser flow cytometry.