Mannosylated Chitosan Nanoparticles for Delivery of Antisense Oligonucleotides for Macrophage Targeting

Abstract

The therapeutic potential of antisense oligonucleotides (ASODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study focuses on designing mannosylated low molecular weight (LMW) chitosan nanoconstructs for safe ODNs delivery by macrophage targeting. Mannose groups were coupled with LMW chitosan and characterized spectroscopically. Mannosylated chitosan ODN nanoparticles (MCHODN NPs) were formulated by self-assembled method using various N/P ratio (moles of amine groups of MCH to phosphate moieties of ODNs) and characterized for gel retardation assay, physicochemical characteristics, cytotoxicity and transfection efficiency, and antisense assay. Complete complexation of MCH/ODN was achieved at charge ratio of 1:1 and above. On increasing the N/P ratio of MCH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) increased. MCHODN NPs displayed much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than Hela cells and no significant toxicity was observed at all MCH concentrations. Antisense assay revealed that reduction in lipopolysaccharide (LPS) induced serum TNF-α is due to antisense activity of TJU-2755 ODN (sequence complementary to 3′-UTR of TNF-α). These results suggest that MCHODN NPs are acceptable choice to improve transfection efficiency in vitro and in vivo.

The different ways to chitosan/hyaluronic acid nanoparticles: templated vs direct complexation. Influence of particle preparation on morphology, cell uptake and silencing efficiency

“…RAW 264.7 macrophages for other HA-based nanomaterials, such as HA-coated liposomes [36] and a library of lipid nanoparticles with surface-anchored HA [37], or chitosan-based carriers, such as mannosylated chitosan nanoparticles [38] or siRNA-entrapped chitosan nanoparticles (with or without TPP) [39]. The innocuous character of HA-coated chitosan nanoparticles in HCT-116 is also consistent with previous studies on HA-based cationic nanocarriers [40,41].…”

Overviews on the cellular uptake mechanism of polysaccharide colloidal nanoparticles

“…Observations have confirmed that the ability to bind specifically to macrophages and transfection efficiency of mannosylated CS nanoparticles containing gastrin‐releasing (pGRP) peptide were significantly higher than those of uncoated particles as macrophages (such as Kupffer cells) express a range of mannose specific membrane receptors which uptake glycoproteins bearing high mannose chains by clathrin‐coated vesicles for delivery into the endosomal system . Furthermore, mannosylated CS nanoparticles exhibited a much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than HeLa cells and successfully found as an ideal targeting gene delivery vehicle to the macrophages . Oleoyl CS nanoparticles have been employed as another promising system for the delivery of hydrophobic antitumour agents.…”

“…CS has been extensively studied as a vehicle for gene transfer into a wide range of cells because of its high efficiency to condense DNA and siRNA . Positively charged CS can compact negatively charged nucleic acids in the form of nanoscale complexes, resulting in protection of the nucleic acids from degradation and improved cellular uptake as compared to the naked nucleic acids .…”

“…After self‐assembly, the highly negative charged nature of nucleic acids becomes neutralized rapidly, and the surface charge of the obtained polyplex gets positive at higher N / P ratio. In fact, this positive charge is required for effective binding to the anionic cell surface, and consequently leading to greater cellular uptake . In addition to electrostatic complexation with the negatively charged nucleic acids, CS alone is able to promote endosomal escape of the loaded cargos into the cytosol by ‘proton sponge’ effect .…”

Nanotechnology and nanocarrier-based approaches on treatment of degenerative diseases

“…These treatment regimes are primarily based on the patternrecognition receptors which are present on the cell surface of macrophages such as the family of scavenger receptors, examples include Fc and complement receptors, mannose receptor Fig. 5 [175][176][177][178][179][180], which are used by macrophages for phagocytosis [181][182][183][184]. In many cases, receptors for amyloid-b peptide [185], high-density lipoprotein [186] and hyaluronic acid [187] were utilized as a candidate for targeted delivery of drug.…”