However, DSPE is not charged under neutral conditions, but the preparation process cannot be completely neutral, so DSPE is negatively charged.
In acidic media (pH <6.2), the surface of TiO2 is positively charged, whereas it is negatively charged under alkaline conditions (pH >6.2).
To investigate the effect on cellular uptake upon derivatization of the PEI layer, we also capped the terminal primary amino groups with either uncharged acetyl groups or acidic (negatively charged under neutral conditions) succinic acid groups.
The PLH segment would become positively charged under acidic conditions, imparting the PLGA-PLH-PEG NP surface an overall positive zeta potential, facilitating interactions with the negatively charged elements of the fungal cell wall leading to strong multivalent electrostatic-mediated binding.
The compounds in the present work bind with a 2∶1 stoichiometry to AT-rich oligonucleotides, despite being pyrrole rich and being potentially multiply charged under the conditions employed.
This is important because the carboxyl groups of acidic peptides are fully charged under these conditions.
Fusion proteins encoding D20 were shown to form a complex with a cationic polymer, polyethylenimine, by electrostatic interaction because the aspartic acid-rich domain is negatively charged under physiological conditions [ 10, 11].
Indeed, the b2 trend for lactoferrin shows that this protein also follows an inverse Hofmeister series at this pH, which is not unexpected as lactoferrin is positively charged under these conditions.
However, as biotin is negatively charged under the conditions used for polymerization of PPy, it can also be incorporated in the polymeric film when used as a doping anion.
1416 and VER have similar chemical features that are shared by other P-gp modulators, such as hydrophobicity and amphiphilcity [ 33], planar aromatic rings with N-aminoalkyl side chain [ 34], positively charged under physiological conditions [ 35].
