Polycationic Polymers in Nucleic Acid Delivery: Membrane Interaction and Cellular Responses.
Year: 2013
Type: dissertation
Abstract: In order to optimize the design of gene delivery vector systems using polycationic polymers, their internalization pathway needs to be extensively studied. In chapter 2, Generation 7 (G7) poly(amidoamine) (PAMAM) dendrimers (G7-NH2) with amine termination were prepared to investigate polymer/cell membrane interaction. C6 cells were employed in this experiment because of their unique characteristic of inherently lacking GM1 but still possessing downstream requirements for successful GM1 mediated endocytosis. This resulted in the reported binary experiment where C6 cells without and with GM1 did not show differential G7-NH2 uptake supporting the hypothesis that GM1 mediated endocytosis is not the primary pathway for G7-NH2 internalization. In addition to understanding uptake mechanisms, efforts to improve the polymer-based vector systems have assumed that cells play a passive role and don’t actively respond to these polymer vector systems. In chapter 3, I will show how cells respond to different polymer systems by activating different levels of cytosolic nucleases and how this nuclease activity can be measured with the help of Molecular Beacon (MB). We also learn that membrane porosity is not the reason for nuclease activation. This nuclease activation decreases gene expression, ultimately decreasing polymer efficiency. In doing this, I show that it is possible to screen multiple polymer-based vector systems, thereby increasing the probability of identifying and designing an efficient polymer vector system. In chapter 4, I will concentrate on DNA degradation characteristics of these cytosolic nucleases. High-throughput sequencing was used to identify and quantify degradation patterns of these cytosolic nucleases on a plasmid. We will also see that S1 nuclease (a known nuclease) has similar degradation pattern as cytosolic nucleases. Designing polymer vector systems that protect these labile sites on DNA can improve gene expression. In chapter 6, invention of The Endocutter, a gastrointestinal device that cuts clots, cuts costs and saves lives is described. This device was designed to be compatible with both single and dual channel endoscope for easy adaptation. Endocutter is easy to use and has been shown to be safe and efficient in removing blood clots both in-vitro and in-vivo systems (http://www.youtube.com/watch?v=gxnB_kuzOsQ )
Author: Rahul Rattan
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W29314097