Hexanoic Acid and Polyethylene Glycol Double Grafted Amphiphilic Chitosan for Enhanced Gene Delivery: Influence of Hydrophobic and Hydrophilic Substitution Degree

Abstract

Gene therapy holds immense potential as a future therapeutic strategy for the treatment of numerous genetic diseases which are incurable to date. Nevertheless, safe and efficient gene delivery remains the most challenging aspects of gene therapy. To overcome this difficulty a series of hexanoic acid (HA) and monomethoxy poly(ethylene glycol) (mPEG) double grafted chitosan-based (HPC) nanomicelles were developed as nonviral gene carrier. HPC polymers with various HA and mPEG substitution degrees were synthesized, and their chemical structures were confirmed by (1)H NMR spectroscopy. HPC nanomicelles exhibited excellent blood compatibility and cell viability, as demonstrated by in vitro hemolysis and MTT assay, respectively. The cationic HPC nanomicelles retained the plasmid DNA (pDNA) binding capacity of chitosan and formed stable HPC/pDNA polyplexes with diameters below 200 nm. Both hydrophobic and hydrophilic substitution resulted in suppressed nonspecific protein adsorption on HPC/pDNA polyplexes and increased pDNA dissociation. However, resistance against DNase I degradation was enhanced by HA conjugation while being inhibited by mPEG substitution. Amphiphilic modification resulted in 3-4.5-fold higher cellular uptake in human embryonic kidney 293 cells (HEK 293) mainly through clathrin-mediated pathway. The optimal HPC/pDNA polyplexes displayed 50-fold and 1.2-fold higher gene transfection compared to unmodified chitosan and Fugene, respectively, in HEK 293 cells. Moreover, both the cellular uptake and in vitro transfection study suggested a clear dependence of gene expression on the extent of HA and mPEG substitution. These findings demonstrate that amphiphilic HPC nanomicelles with the proper combination of HA and mPEG substitution could be used as a promising gene carrier for efficient gene therapy.

Amino Acid-Modified Polyethylenimines with Enhanced Gene Delivery Efficiency and Biocompatibility

“…The binding strength of the modified PEIs to plasmid DNA was determined by gel retardation assay at various weight ratios (polymer/DNA, w/w), and the binding ability was indicated by the ratio at which full retardation was achieved [19]. Figure 2 shows that the complete DNA retardation induced by these new materials could be observed at a w/w ratio of 0.8, and the DS did not affect the DNA condensation ability [20]. Among the five modifications, Deta-PEI shows slightly lower binding ability.…”

Linear TACN-based cationic polymers as non-viral gene vectors

“…1 MeOH-HCl solution (100 mL) was added to a stirred solution of compound 1 in anhydrous chloroform (20 mL), and then the reaction mixture was stirred for 24 h at room temperature. The resulting reaction mixture was stirred for 24 h at room temperature.…”

“…1,2 The naked DNA is highly susceptible to nuclease degradation and displays poor cellular uptake, as well as low transfection efficiency (TE). 1,2 The naked DNA is highly susceptible to nuclease degradation and displays poor cellular uptake, as well as low transfection efficiency (TE).…”

Paclitaxel and quercetin nanoparticles co-loaded in microspheres to prolong retention time for pulmonary drug delivery

“…33 Therefore, due to its cationic nature which allows ionic cross-linking with multivalent anions, CTS is particularly suitable for developing NPs, and its availability for group modification occurs through its free amino groups in acidic aqueous solutions. 34 In comparison with the unmodified CTS, OA-modified CTS shows improved DL and enhanced stability of NPs because the long hydrophobic chains in CTS could aid the increase in hydrophobic interaction with PTX and QUE. [35][36][37] Recently, pulmonary delivery has been shown to be an increasingly attractive route for chemotherapeutic drugs and increases their accumulation in tumor cells because of the enormous surface area for absorption, highly permeable epithelium compared with the gastrointestinal tract, and avoidance of the first-pass hepatic metabolism.…”