Structure-Skin Permeability Relationship of Dendrimers

Abstract

The study demonstrates that the physicochemical properties of dendrimers influence their skin transport. Findings can be used to design dendrimer-based nanocarriers for drug delivery to skin.

Iontophoresis-Mediated Transdermal Permeation of Peptide Dendrimers across Human Epidermis

“…This implied that peptide dendrimers have the potential to swiftly deliver conjugated/complexed drug payloads when iontophoresis is applied. Our findings of passive diffusion and iontophoresis are consistent with previous results, where surface confocal images and hematoxylin-stained skin cryosections showed that the PAMAM dendrimer (G4-NH 2 ) was mostly distributed in stratum corneum upon passive diffusion; but in presence of iontophoresis, the dendrimer was found in viable epidermis with some permeation detected in the upper dermis layer [7]. …”

“…Accordingly, the flux values decreased significantly (p < 0.05) with an increase in molecular weight of dendrimers (≈ two-fold increase from 4 + to 8 + dendrimer and 8 + to 16 + dendrimer) although the positive charge density doubled from 4 + to 8 + dendrimer and then 8 + to 16 + dendrimer. These results are in accordance with a previous report in which the extent of skin permeation of PAMAM dendrimers decreased with increasing molecular weight [7]. The isoelectric point of the skin also cannot be ruled out for the enhanced iontophoretic transdermal permeation of peptide dendrimers.…”

“…Contrasting the aforementioned carriers, very little is known about the penetration properties of dendritic carriers through skin. Dendrimers have been considered amongst some of the most promising new scaffolds for drug/gene delivery with a wider range of applications such as protein mimetics and vaccine engineering, antiviral and anticancer properties also proposed [7]. …”

“…In our previous report, we successfully carried out a preliminary study on the effect of iontophoresis on the skin permeation of peptide dendrimers and noted the importance of a positive electric charge on the peptide dendrimers in transporting dendrimers across human skin [25]. Recently, skin penetration of PAMAM dendrimers in presence and absence of iontophoresis has been investigated across excised porcine skin [7]. Key to developing peptide dendrimer-based drug carriers for skin delivery is the necessity to first understand the parameters that dictate their skin transport.…”

Biomaterials as novel penetration enhancers for transdermal and dermal drug delivery systems

“…In another study, Filipowicz et al (2011) also reported that the small-sized G2-NH 2 dendrimer might be a more potent penetration enhancer than the larger ones for the transdermal absorption of the hydrophilic drug (riboflavin) from the emulsions or hydrogels. Additionally, use of iontophoresis could further increase the skin penetration of cationic and neutral dendrimers into viable epidermis, which provided an effective method to delivery macromolecules into and across the skin (Venuganti et al, 2011).…”