Subcategory: Biomedical Engineering
Natalie Faciane - Xavier University of Louisiana
Co-Author(s): Nsoki Phambu, University of Tennessee, TN Anderson Sunda-Meya, Xavier University of Louisiana, LA
The main problem of drug delivery lies in the penetration of cellular membranes. In recent years, the development of agents that can cross the membranes and deliver therapeutic agents inside the cell has attracted increased attention. Peptides have been used as delivery agents capable of crossing the membrane barriers. These cell penetrating peptides (CPPs) are cationic peptides which, when linked to proteins, genes, or nanoparticles, facilitate the transport of these entities across the cell membrane. They are short peptides (fewer than 30 residues) with a net positive charge and acting in a receptor- and energy-independent manner. They have been previously shown to be powerful transport vector tools for the intracellular delivery of a large variety of cargoes through the cell membrane. They have been successfully applied for in vitro and in vivo delivery of a variety of therapeutic molecules plasmid DNA (pDNA), oligonucleotides, small interfering RNAs (siRNAs), proteins and peptides, contrast agents, drugs, as well as various nanoparticulate pharmaceutical carriers (e.g., liposomes, micelles). The objective of this study is to measure the effects of the cell penetrating peptide Pep-1 on vesicles from Escherichia coli (E. coli) membranes using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The interaction was performed in a wide range of peptide-to-lipid molar ratios in liquid and freeze-dried states. E coli membrane sample presents large particles of undefined shapes and sizes. Upon Pep-1 addition, elongated fibrils of a few micron sizes appear. SEM and AFM images suggest that Pep-1 disrupt E coli mimicking membranes. Pep-1 have a similar effect on E coli vesicles and these effects do not depend on peptide concentration. Overall, SEM and AFM are able to give information at the microscopic/macroscopic level. Further studies using techniques such as Fourier transform (TFIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are needed to provide information at the molecular level.
Funder Acknowledgement(s): This research was funded, in part, under the grant # HRD 1411209 a grant from the National Science Foundation awarded to Anderson Sunda-Meya.
Faculty Advisor: Anderson Sunda-Meya, firstname.lastname@example.org
Role: I prepared the samples, ran the experiment, and ran measurments on the SEM. In addition I processed and analyzed the images.