Evaluation of cystamine-modified hyaluronic acid/chitosan polyplex as retinal gene vector

Abstract

Purpose: A successful gene therapy approach can prevent or treat congenital and acquired diseases. However, there is still no ideal non-viral vector for gene delivery in a safe and timely manner. In this report the anionic polymer hyaluronic acid (HA) was investigated as a potential vector for gene therapy. Due to its intrinsic characteristics it constitutes an excellent candidate to deliver therapeutic genes, pending the modification of its surface charge. Methods: To modify its charge, HA was modified with cystamine. Several formulations were prepared using modified HA combined with sodium sulfate, sodium triphosphate, K-carrageenan and chitosan. Vectors were characterized with respect to size, charge, DNA load and its protection, and effect on cell viability. The better performing formulations were further evaluated in vitro for their transfection efficiency in HEK293T and ARPE-19 cells. Results: Cell viability assays showed low cytotoxicity for both polymers. Gene transfer efficiency depended on cell line and formulation, but no increased transfection efficiency was observed with the modified polymer. Conclusions: HA has great potential as a gene therapy vector, but further optimization, including incorporation of a higher percentage of positive groups in HA, is needed before its use as a gene delivery vector.

Hyaluronic acid coating of gold nanoparticles for intraocular drug delivery: Evaluation of the surface properties and effect on their distribution

“…Thiol-functionalized HA (MW 5K, Lifecore™ Biomedical, USA) was prepared by carboxylic acid crosslinking following the procedure previously described elsewhere (Oliveira et al, 2016) with some modifications. Briefly, 100 mg HA5K, a half molar excess of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC, 75.6 mg, pH 4, Sigma-Aldrich Chemie GmbH, Munich, Germany) and 177.8 mg cystamine dihydrochloride (Sigma-Aldrich Chemie GmbH, Munich, Germany) were incubated for 72 h at room temperature under continuous agitation, the reaction was stopped by addition of 4M NaOH.…”

The Landscape of Non-Viral Gene Augmentation Strategies for Inherited Retinal Diseases

“…Subretinal injections of 5.7 kb-long GFP plasmid DNA glycol chitosan nanoparticles in albino wild-type mice resulted in GFP expression in the RPE cells, without any safety concerns [ 46 ]. The safe profile of chitosan-derived nanoparticles makes them a strategy of interest for retinal gene therapy; however, modification and optimization still need to be explored to improve the low efficiency [ 47 , 48 ].…”

Human-derived NLS enhance the gene transfer efficiency of chitosan

“…Parameters as N:P ratio, molecular weight, mixing technique, among others, have been widely investigated on CS-DNA complexes [30,[32][33][34], and described as factors that influence the binding affinity between chitosan and DNA, size and charge of polyplexes, cellular uptake and dissociation of DNA, and thus, transfection efficiency [35][36][37]. Based on our previous work [10][11][12][13][14], an amine to phosphate (N:P) ratio of 15:1 was chosen to promote the formation of positively charged polyplexes and avoid repulsion by the negative cell surface.…”