Optimization of chitosan-based polyelectrolyte nanoparticles for gene delivery, using design of experiment: in vitro and in vivo study.

Gene therapy is a novel approach for cancer treatment and investigation for suitable gene delivery systems is remarkable. Here, preparation of a polyelectrolyte complex containing polysaccharides: trimethyl chitosan (TMC) as the positive and hyaluronate (HA), dextran sulfate and alginate as the negative part was studied. The optimized nanoparticles (TMC: between 0.2 and 0.47 mg/ml, HA: 0.35 mg/ml (≈131 nm, nearly full gene loading)) were obtained via primary screening followed by the D-optimal method. In vitro cellular study on the MCF7 cell line confirmed the non-toxicity and high cellular uptake (>90%) of prepared nanoparticles. Notably, in vivo study indicated noticeable tumor uptake of nanoparticles while low accumulation in vital organs such as heart, liver and lungs. Moreover, although a qualitative variable was considered, the applied method restricted the number of runs by selecting spots from the spherical atmosphere. The prepared nanoparticles could be suggested as an efficient and safe delivery system for cancer gene delivery.

Controlling evolution of protein corona: a prosperous approach to improve chitosan-based nanoparticle biodistribution and half-life.

Protein corona significantly affects in vivo fate of nanoparticles including biodistribution and half-life. Without manipulating the physicochemical properties of nanoparticles with considering their biointerference, attaining effective treatment protocols is impossible. For this reason, protein corona evolution and biodistribution of different chitosan (Ch)-based nanoparticles including Ch and carboxymethyl dextran (CMD)/thiolated dextran (TD) polyelectrolyte complexes (PECs) were studied using highly precious and sensitive methods such as liquid chromatography-mass/mass (LC-MS/MS) spectroscopy and positron emission tomography/computed tomography (PET/CT) scan. The importance of serum presence/absence in culture medium with different pH and corona effect on cellular uptake of PECs investigated by in vitro study. Designed PECs have low amounts of proteins in corona mostly enriched by Apolipoproteins, protein C, hemoglobin subunits, and inter-alpha- trypsin inhibitor that beside improving uptake of nanoparticles, they have low liver uptake and notable heart blood pool accumulation that confirmed the long circulation time of the nanoparticles which is favorable for delivery of nanoparticles to the site of action and achieving required therapeutic effect.

Carboxymethyl dextran-trimethyl chitosan coated superparamagnetic iron oxide nanoparticles: An effective siRNA delivery system for HIV-1 Nef.

Gene therapy, including small interfering RNA (siRNA) technology, is one of the leading strategies that help to improve the outcomes of the current therapeutic systems against HIV-1 infection. The successful therapeutic application of siRNAs requires their safe and efficient delivery to specific cells. Here, we introduce a superparamagnetic iron oxide nanoparticle (SPION) for delivering siRNA against HIV-1 nef (anti-nef siRNA) into two cell lines, HEK293 and macrophage RAW 264.7. SPIONs were coated with trimethyl chitosan (TMC), and thereafter, different concentrations of SPION-TMC were coated with different ratios of a carboxymethyl dextran (CMD) to modify the physicochemical properties and improve the biological properties of the nanocarriers. The nanoparticles exhibited a spherical shape with an average size of 112 nm. The obtained results showed that the designed delivery route enhanced the uptake of siRNA into both HEK293 and RAW 264.7 cells compared with control groups. Moreover, CMD-TMC-SPIONs containing anti-nef siRNA significantly reduced the expression of HIV-1 nef in HEK293 stable cells. The modified siRNA-loaded SPIONs also displayed no toxicity or apoptosis-inducing effects on the cells. The CMD-TMC-SPIONs are suggested as potential nanocarriers for siRNA delivery in gene therapy of HIV-1 infection.

Glutathione responsive chitosan-thiolated dextran conjugated miR-145 nanoparticles targeted with AS1411 aptamer for cancer treatment.

miR-145 is a tumor suppressive miRNA which is abnormally reduced in different cancers. miR-145 overexpression reduces cancer migration, invasion, and cell adhesion. Increasing miR-145 level using suitable and efficient gene delivery systems could be valuable in cancer treatment. In this study, a redox-responsive miR-145 conjugated thiolated dextran (TD-miR) was prepared. Also, polyelectrolyte complexes (PECs) of TD-miR and chitosan were fabricated and decorated with anti nucleolin aptamer, AS1411 (apt-PEC). The size of the PECs was between 40-270 nm, and the zeta potential was varied according to the TD-miR to chitosan molar ratio. The outcomes of cellular studies indicated the excellence of the apt-PEC as a duel targeted delivery system and the PECs composed of chitosan 18 kDa with TD-miR to chitosan ratio of 5. TD-miR and the PECs are appropriate as the smart gene delivery systems which preserve and transfect the cargo and release it in cytoplasm.

Chitosan polyplex nanoparticle vector for miR-145 expression in MCF-7: Optimization by design of experiment.

miR-145, a tumor suppressor micro RNA (miRNA), is down regulated in cancer and can be introduced as a therapeutic agent in various cancers including breast cancer. In this study, miR-145 plasmid was transfected to MCF-7 cells using chitosan polyplex nanoparticles. The vector was prepared according to an optimized fabricating method determined by response surface analysis and D-optimal design. Effects of chitosan molecular weight (Mw) and polymer amine to DNA phosphate ratio (N/P) as the variables were investigated on size, zeta potential, stability, and transfection efficiency of the polyplex nanoparticles. The results indicated that there is an interaction between effects of Mw and N/P ratio on the size of nanoparticles. Gel retardation assay demonstrated that the stability of the complexes in serum and preparation medium during storage time depends on the formulation variables. Statistical analysis affirmed that in spite of particle size, the variables of N/P ratio, time of incubation, and zeta potential affect the gene transfection. In conclusion, by selecting the perfect formulation prepared through an optimized method, it is possible to achieve a high transfection efficacy for miR-145 as an anticancer biological macromolecule.