Pharmacy Division Birla Institute of Technology and Science, Pilani-Hyderabad Campus Jawahar Nagar Shameerpet Mandal, Hyderabad 500078, Andhra Pradesh, India.
Pharm Res. 2011 Sep;28(9):2246-60. doi: 10.1007/s11095-011-0455-0. Epub 2011 Jun 2.
To investigate skin penetration of poly (amidoamine) (PAMAM) dendrimers as a function of surface charge and molecular weight in presence and absence of iontophoresis.
Dendrimers were labeled with fluoroisothiocynate (FITC); skin penetration of dendrimers was studied using excised porcine skin in-vitro. Skin penetration of FITC-labeled dendrimers was quantified using confocal laser scanning microscope (CLSM). G2-G6 NH(2), G3.5-COOH and G4-OH dendrimers were used.
Cationic dendrimers showed higher skin penetration than neutral and anionic dendrimers. Skin penetration of cationic dendrimer increased linearly with increase in treatment time. Iontophoresis enhanced skin penetration of cationic and neutral dendrimers. Increase in current strength and current duration increased skin transport of dendrimers. Passive and iontophoretic skin penetration of cationic dendrimers was inversely related to their molecular weight. Dendrimer penetrated the skin through intercellular lipids and hair follicles. With iontophoresis, dendrimer was also found in localized skin regions.
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.
研究聚酰胺-胺（PAMAM）树枝状大分子的表面电荷和分子量对其经皮渗透的影响，以及有无离子导入的情况下的影响。
用荧光异硫氰酸酯（FITC）标记树枝状大分子；采用离体猪皮研究 FITC 标记的树枝状大分子的经皮渗透情况。使用共聚焦激光扫描显微镜（CLSM）定量测定 FITC 标记的树枝状大分子的经皮渗透。使用 G2-G6 NH（2）、G3.5-COOH 和 G4-OH 树枝状大分子。
阳离子树枝状大分子的皮肤穿透性高于中性和阴离子树枝状大分子。阳离子树枝状大分子的皮肤穿透性随处理时间的增加而线性增加。离子导入增强了阳离子和中性树枝状大分子的皮肤穿透性。增加电流强度和电流持续时间增加了树枝状大分子的皮肤转运。阳离子树枝状大分子的被动和离子导入皮肤渗透与其分子量呈反比。树枝状大分子通过细胞间脂质和毛囊渗透皮肤。通过离子导入，也可以在局部皮肤区域找到树枝状大分子。
该研究表明，树枝状大分子的物理化学性质影响其皮肤转运。这些发现可用于设计基于树枝状大分子的纳米载体，以将药物递送至皮肤。
