EFFECT OF SIZE AT THE NANOSCALE AND BILAYER RIGIDITY ON SKIN DIFFUSION OF LIPOSOMES.

• TR Number: 520
• Keywords: EPI-606-X, EpiDerm, Lamellar bilayers, Lipid bilayers, Liposome particle size, Liposomes, Particle size, Permeation, Skin diffusion

This study by researchers at Drexel University’s School of Biomedical Engineering and the Dept. of Dermatology and Cutaneous Biology at Jefferson Medical College (Thomas Jefferson Univ.) demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent can be used to determine the permeation characteristics of liposomes by their particle size at the nanoscale level. This study reports the effect of liposome particle size at the nanoscale and bilayer deformability on the permeation through Mattek human skin equivalents and provides a comparative quantitative measure through calculation of diffusion coefficients. Exploring DOPC and DPPC fluorescent liposomes, our results demonstrate the faster diffusion of 50 nm liposomes compared with 100 and 200 nm liposomes when the lipid bilayer remains the same. Diffusion kinetics of the 50 nm particles appear not to depend on the rigidity of the lipid layer, whereas diffusion of particles larger than 100 nm is significantly affected by the rigidity of the bilayer, and DOPC liposomes diffuse faster than their DDPC equivalents. Our results suggest that liposomes composed of a rigid bilayer can be expected to remain intact after passing through the stratum corneum.