A Simple Egg Membrane Model for Understanding Diffusion Characteristics of Nanoparticles and Amino Acids

This study reports the passive diffusion (in vitro) of silver nanoparticles (SNPs) and those of the amino acids tryptophan, phenylalanine, tyrosine across a biological membrane model. The experiments were carried out under physiological conditions at pH 7.4. Chicken egg shell outer membrane model was used to study the passive diffusion of the above materials. Passive diffusion was performed against and towards gravitation for 24 and 48 h. Fick's first law of diffusion was adopted for quantification of diffusion coefficient, permeability constant and diffusion rate. The egg shell membrane was characterized using scanning electron microscopy. The SNPs were synthesized by chemical degradation method and characterized by UV-visible spectroscopy and dynamic light scattering. An average size of nanoparticles obtained was 62 nm. The diffusion rates of amino acids were higher than those of SNPs. However, they were enhanced in their presence. Permeability coefficient and diffusion coefficient were higher for amino acids than SNPs. The possible mechanisms have been explained on the basis of molecular properties.