Biophysical and Transfection Studies of an Amine-Modified Poly(vinyl alcohol) for Gene Delivery

Abstract

Novel, multifunctional polymers remain an attractive objective for drug delivery, especially for hydrophilic macromolecular drugs candidates such as peptides, proteins, RNA, and DNA. To facilitate intracellular delivery of DNA, new amine-modified poly(vinyl alcohol)s (PVAs) were synthesized by a two-step process using carbonyl diimidazole activated diamines to produce PVAs with different degrees of amine substitution. The resulting polymers were characterized using NMR, thermogravimetric analysis (TGA), and gelpermation chromatography (GPC). Atomic force microscopy (AFM), dynamic light scattering photon correlation spectroscopy (PCS), and zeta-potential were used to investigate polyplexes of DNA with PVA copolymers. These studies suggest an influence of the polycation structure on the morphology of condensed DNA in polyplexes. Significant differences were observed by changing both the degrees of amine substitution and the structure of the PVA backbone, demonstrating that both electrostatic and hydrophobic interactions affect DNA condensation. DNA condensation measured by an ethidium bromide intercalation assay showed a higher degree of condensation with pDNA with increasing degrees of amine substitution and more hydrophobic functional groups. These findings are in line with transfection experiments, in which a good uptake of these polymer DNA complexes was noted, unfortunately, with little endosomal escape. Co-administration of chloroquine resulted in increased endosomal escape and higher transfection efficiencies, due to disruption of the endosomal membrane. In this study, the structural requirements for DNA complexation and condensation were characterized to provide a basis for rational design of nonviral gene delivery systems.

Enhanced gene expression through temperature profile‐induced variations in molecular architecture of thermoresponsive polymer vectors

“…This methodology was used so as to obtain as representative random samples of the population of complexes as possible [20].…”

Uptake efficiency of surface modified gold nanoparticles does not correlate with functional changes and cytokine secretion in human dendritic cells in vitro

“…It also has been shown by Wittmar and Nguyen that aminated PVA can cause cytotoxicity in L929 mouse fibroblasts and SKOV-luc human ovary cancer cells. 41,42 The potential for AuNPs to cause a (pro-)inflammatory cellular response was addressed by measuring cytokine secretion. TNF-α and IL-1β have been investigated, since they are involved in lung diseases by the activation of different (pro-)inflammation pathways and the inflammasome activation pathway.…”

Functional Polymers for Drug Delivery Systems in Nanomedicines

“…Various other synthetic polymer vectors are currently being tested for gene delivery research including poly(4-vinylimidazole) (Ihm et al 2003), poly(vinyl alcohol) (Wittmar et al 2005), polyallylamine derivatives (Boussif et al 1999), etc. These polymers showed promising properties for gene delivery (Table II).…”

“…Kissel's group presented the biophysical and transfection studies of an amine modified poly(vinyl alcohol) for gene delivery (Wittmar et al 2005). Significant differences in physicochemical properties of the polyplex with DNA were observed by changing both the degrees of amine substitution and the structure of the PVA backbone, demonstrating that both electrostatic and hydrophobic interactions affected DNA condensation.…”