Authors: A.M. Zaske, D. Danila, M.C. Queen, E. Golunski, J.L. Conyers
Affilation: University of Texas Health Science Center at Houston, United States
Pages: 368 - 371
Keywords: liposomes, AFM, endocytosis, gold particles, HCAEC
Engineering of non-toxic nanoparticles for tissue-specific targeting has gained widespread attention this decade. Liposomes were one of the earliest classes of engineered nanoparticles to be utilized for the purpose of delivering drugs within the human body. While many have successfully designed and tested such “nanovectors” in vivo, little is known about how these particles dynamically interact with cell membranes. Atomic Force Microscopy (AFM) is a surface analytical technique that generates nano-scale topographic images under physiological conditions. AFM combined with fluorescence microscopy, is an attractive tool for interrogating nanoparticle:cell membrane interactions and may afford the opportunity to image biological processes, such as cellular endocytosis of nanovectors, in real-time. Nevertheless, the topographical structure of the cell membrane itself is complex, rich in natural corrugations and ridges. These surface characteristics obscure the identification of extracellular structures when using AFM for membrane imaging. The aim of this project was to standardize the use of 90nm nano-gold particles as a non-toxic means to detect immuno-liposomes on the membrane of living cells to elucidate internalization processes and binding efficiency on Human Coronary Artery Endothelial Cells (HCAEC) using AFM. We established a potential method to track biological materials. The 90nm colloidal gold nanoparticles resulted in a non invasive contrast agent that efficiently improved the visual enhancement when using AFM to study biological nanoprocesses.