The interaction mechanism between lipopeptide (daptomycin) and polyamidoamine (PAMAM) dendrimers.

The interaction mechanism of lipopeptide antibiotic daptomycin and polyamidoamine (PAMAM) dendrimers was studied using fluorescence spectroscopy. The fluorescence changes observed are associated with daptomycin-dendrimer interactions. The binding isotherms were constructed by plotting the fluorescence difference at 460 nm from kynurenine (Kyn-13) of daptomycin in the presence and absence of dendrimer.

Type I pro-collagen promoting and anti-collagenase activities of Phyllanthus emblica extract in mouse fibroblasts.

As part of an ongoing search for the novel pharmacological activities of Phyllanthus emblica, the present study has shown its type I collagen promoting and anti-collagenase effects on primary mouse fibroblast cells. At a concentration of 0.1 mg/ml, emblica extract significantly increased the type I pro-collagen level up to 1.

An evaluation of a fluorometric method for determining binding parameters of drug-carrier complexes using mathematical models based on total drug concentration.

A fluorescence method for determining the mode of binding and estimating binding parameters in a model drug-carrier complex was developed using the lipopeptide antibiotic daptomycin and polyamidoamine (PAMAM) dendrimer. Mathematical simulations of model equations describing fluorescence changes induced by antibiotic-carrier binding in terms of total drug concentration were used to evaluate the sensitivity of parameter variation on binding isotherms for both one- and two-site binding models. Nonlinear regression analysis was used to estimate binding parameters and to identify pH-dependent binding models.