Objectives. Human breast milk contains a heterogeneous population of cells that have the potential to provide a noninvasive source of cells for cell therapy in many neurodegenerative diseases without any ethical concern. The objectives of this study were to differentiate the breast milk-derived stem cells (BMDSC) toward neural stem cells and then into the neurons and neuroglia. Materials and Methods. To do this, the BMDSC were isolated from human breast milk and cultured in Dulbecco's modified Eagle medium/F12 (DMEM/F12) containing fibroblast growth factor (bFGF). The cells were then characterized by evaluation of the embryonic and stem cell markers. Then, the cells were exposed to culture medium containing 1% B27 and 2% N2 for 7–10 days followed by medium supplemented with B27, N2, bFGF 10 µg/mL, and endothelial growth factor (EGF) 20 µg/mL. Then, the sphere-forming assay was performed. The spheres were then differentiated into three neural lineages by withdrawing growth factor in the presence of 5% FBS (fetal bovine serum). The immunofluorescence was done for β-tubulin III, O4, and GFAP (glial fibrillary acidic protein). Results. The results indicated that the cells expressed both embryonic and mesenchymal stem cell (MSC) markers. They also showed neurospheres formation that was nestin-positive. The cells were also differentiated into all three neural lineages. Conclusion. The BMDSC can behave in the same way with neural stem cells. They were differentiated into oligodendrocytes, and astrocytes as well as neurons.

To improve transfection of plasmid DNA as well as serum protein stability of polyionic complex nanoparticles of branched polyethyleneimine (bPEI), poly(ethylene glycol) (PEG)-stabilized nanoparticles were made from L-histidine substituted bPEI (PEI-Histidine) synthesized by Fmoc chemistry. The polymer was characterized by TNBS assay, 1 H NMR, GFC, potentiometric titration and elemental analysis of carbon and nitrogen, DNA condensation, and the stability against extracellular matrix (heparin sulfate) was investigated by dye exclusion and agarose gel retardation assays. The nanoparticles were characterized by dynamic light scattering-zeta potential analyzer. Cytotoxicity and expression of enhanced green fluorescent protein (EGFP) were determined in hepatocellular carcinoma by MTT assay and fluorescent techniques. PEI-Histidine showed a reduced pK a without any significant loss of total primary amines. Plasmid DNA was condensed almost thoroughly with PEGylated polymers, either bPEI or PEI-Histidine, at lower critical N/P ratios. PEGylated PEI-Histidine showed the better resistance to heparin induced displacement and the lower cytotoxicity when it was compared to bPEI. Interestingly unlike bPEI, smaller and less positively charged nanoparticles were obtained from PEGylated PEI-Histidine at N/P ratio=2 that resulted in about 4 folds higher EGFP expression than bPEI without any significant cytotoxicity. These properties are consistent with the higher serum protein resistance and buffer capacity of PEGylated PEI-Histidine at endosomal acidic pH.

Uropathogenic Escherichia coli (UPEC) strains are found in high numbers in the gut of patients with urinary tract infections (UTIs). We hypothesised that in hospitalised patients, UPEC strains might translocate from the gut to the blood stream and that this could be due to the presence of virulence genes (VGs) that are not commonly found in UPEC strains that cause UTI only. To test this, E. coli strains representing 75 dominant clonal groups of UPEC isolated from the blood of hospitalised patients with UTI (urosepsis) (n = 22), hospital-acquired (HA) UTI without blood infection (n = 24) and strains isolated from patients with community-acquired (CA)-UTIs (n = 29) were tested for their adhesion to, invasion and translocation through Caco-2 cells, in addition to the presence of 34 VGs associated with UPEC. Although there were no differences in the rate and degree of translocation among the groups, urosepsis and HA-UTI strains showed significantly higher abilities to adhere (P = 0.0095 and P < 0.0001 respectively) and invade Caco-2 cells than CA-UTI isolates (P = 0.0044, P = 0.0048 respectively). Urosepsis strains also carried significantly more VGs than strains isolated from patients with only UTI and/or CA-UTI isolates. In contrast, the antigen 43 allele RS218 was found more commonly among CA-UTI strains than in the other two groups. These data indicate that UPEC strains, irrespective of their source, are capable of translocating through gut epithelium. However, urosepsis and HA-UTI strains have a much better ability to interact with gut epithelia and have a greater virulence potential than CA-UPEC, which allows them to cause blood infection.

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