0000000000146232
AUTHOR
E. Di Leonardo
Formulation of Different Chitosan Hydrogels for Cartilage Tissue Repair
Different formulations of Chitosan/sulphate and Chitosan/PEGDE were produced by physical and chemical reticulation to obtain hydrogels with better physiochemical properties. The hydrogels were analyzed – in terms of their non-toxicity, proliferative, differentiative, inflammatory and immunology responses. Commercial grade Chitosan (Sigma) was solubilized and purified by progressive filtrations. Then, the polymer was freeze-dried in a water soluble cationic form. A physical hydrogel was prepared by mixing a 3 % w/w water solution of the a.m. polymer with different stoichiometric ratios of (SO4=) 1/0.5;1/0.75;1/1 respectively. The hydrogels were cross-linked in multiwells. The chemical hydrog…
Differentiative pathway activated by 3-aminobenzamide, an inhibitor of PARP, in human osteosarcoma MG-63 cells
AbstractThis study describes the molecular mechanism by which treatment with 3-AB, a potent inhibitor of PARP, allows human osteosarcoma MG-63 cells to restrict growth and enter differentiation. Our findings show that in MG-63 cells, aberrant gene expression keeps Rb protein constitutively inactivated through hyperphosphorylation and this promotes uncontrolled proliferation of the cells. After 3-AB-treatment, the poly(ADP-ribosyl)ation of nuclear proteins markedly decreases and this results in an increase in both the hypophosphorylated active form of Rb and pRb/E2F complexes. These effects are accompanied by G1 arrest, downregulation of gene products required for proliferation (cyclin D1, β…
Histone deacetylase inhibitors induce in human hepatoma HepG2 cells acetylation of p53 and histones in correlation with apoptotic effects
This report shows that histone deacetylase inhibitors (HDACIs) induced apoptosis in human hepatoma HepG2 cells in a dose- and time-dependent manner. Trichostatin A (TSA), ITF2357 and suberoylanilide hydroxamic acid (SAHA), which were very effective agents, caused apoptotic effects after a lag phase of 12-16 h. In order to elucidate the mechanism of HDACIs action in HepG2 cells we have studied the effects of TSA, ITF2357 and SAHA on acetylation of p53 and histones H2A, H2B, H3 and H4. It was observed that HDACIs rapidly induced acetylation of these proteins, being the effects clearly visible already at 30 min of treatment at the same doses which caused apoptosis. Analysis of the immunocomple…