Macrophage physiological function after superparamagnetic iron oxide labeling.

Our goal was to analyze the changes in morphology and physiological function (phagocytosis, migratory capabilities, humoral and cellular response, and nitric oxide secretion) of murine macrophages after labeling with a clinically used superparamagnetic iron oxide (SPIO), ferucarbotran. In SPIO-treated macrophages, nanoparticles were taken up in the cytoplasm and accumulated in a membrane-bound organelle. Macrophage proliferation and viability were not modified after SPIO labeling.

Magnetic nanoparticle labeling of mesenchymal stem cells without transfection agent: cellular behavior and capability of detection with clinical 1.5 T magnetic resonance at the single cell level.

The purpose of this work was to evaluate the efficacy of labeling human mesenchymal stem cells (hMSCs) by ionic superparamagnetic iron oxide (SPIO) without a transfection agent and verifying its capability to be detected with clinical 1.5 T magnetic resonance (MR) at the single-cell level. Human hMSCs were incubated for 24 h with an ionic SPIO, Ferucarbotran.

Mutations in the alpha-helix directly C-terminal to the major homology region of human immunodeficiency virus type 1 capsid protein disrupt Gag multimerization and markedly impair virus particle production.

The X-ray crystallographic structure of HIV-1 capsid protein suggests that the dimer interface of the dimerization domain is mainly formed from a putative alpha-helix structure of 14 amino acids (Gag residues 311-324) and lies directly C-terminal to the capsid major homology region. We found that a deletion mutation in the alpha-helix drastically reduces virus particle production. Alanine-scanning mutagenetic analysis indicated that substitution mutations at residues Q311, V313, K314, W316, and M317 all impair virus particle production markedly.