Polymeric Propranolol Nanoparticles for Intraocular Delivery: Formulation, Characterization, and Vitreous Pharmacokinetics.

Purpose: Recent studies have reported the promising effect of intravitreal propranolol on retinal neovascularization. However, rapid clearance and short half-life of the drug in the vitreous are the main drawbacks of this therapeutic approach. This study investigates the extension of the residence time of propranolol in the vitreous by polymeric nanoparticles (NPs) with the prospect of improving choroidal neovascularization treatment. Methods: The poly (lactic-co-glycolic) acid (PLGA) NPs were fabricated by a modified double emulsion solvent evaporation method and the obtained NPs were characterized for their size, poly dispersity index (PDI), and surface image. The in vitro release, cell cytotoxicity, and uptake of NPs were also evaluated. To investigate the effect of the vitreous pharmacokinetic drug loaded NPs versus that of the free propranolol, they were intravitreally injected into the rabbits' eyes and the drug vitreous concentrations in defined intervals were analyzed by high performance liquid chromatography (HPLC). Results: The spherical NPs with about 230 nm size, and almost 10% drug loading were obtained. Based on the 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium Bromide (MTT) outcomes, 30 µg/ml of propranolol was considered as the guide dosage in the intravitreal injection. Confocal microscopy images verified the presence of labeled NPs in the posterior segment after five days of receiving the injection. In vivo assay revealed that the vanishing rate of propranolol in rabbits treated with propranolol NPs was reduced at twice the rate as compared to that of the vanishing rate experienced with only the free drug. Conclusion: PLGA NPs can prolong the existence of propranolol in both vitreous and posterior ocular tissues, and thus, may provide an effective approach in treatment of posterior segment neovascularization.

Trimethyl chitosan-hyaluronic acid nano-polyplexes for intravitreal VEGFR-2 siRNA delivery: Formulation and in vivo efficacy evaluation.

As vascular endothelial growth factor in choroidal neovascularization is a major cause of visual loss of the elderlies and diabetics, gene therapy may offer an alternative treatment. However, siRNA instability and inefficient delivery are the main hindrances. To address this issue, we developed a nano-sized siRNA loaded therapeutic delivery system. The chitosan-hyaluronic acid nano-polyplexes were prepared by the modified ionic gelation method. The obtained nano-polyplex with a narrow size distribution, indicated no significant cytotoxicity in the MTT test and proper cellular uptake in confocal images. The RT-PCR analysis indicated remarkable gene silencing on HUVEC cells. The intravitreally administered nano-polyplexes in rabbits overcame both the vitreous and retina barriers and reached the posterior tissues efficiently. Intravitreal injections of the VEGFR-2 siRNA nano-polyplexes significantly reduced the size of the laser-induced choroidal neovascularization, compared to the control group. Consequently, the developed formulation can be a promising candidate for intravitreal delivery of siRNA.

Formulation and in vitro evaluation of curcumin-lactoferrin conjugated nanostructures for cancerous cells.

Curcumin, a natural polyphenol, exhibits anti-oxidant, anti-inflammatory, anti-neoplastic and chemopreventive properties. In fact, targeting of this natural anticancer agent has received a great deal of attention during the recent years. In this study, we proposed that curcumin conjugation with lactoferrin molecules may lead to a potential drug delivery system targeted toward cancerous cells through both active and passive targeting. In this regard, curcumin conjugated lactoferrin was developed via a carbodiimide-based coupling reaction and the resulting conjugates were appraised for their molecular properties as a potential targeted drug delivery system. The mean diameter of the designed nanostructure was about 165 ± 26 nm with a PDI of 0.308 ± 0.045. The conjugated nanostructures showed a considerably improved cytotoxicity on HCT116 cells as illustrated by MTT assay along with a higher level of cellular uptake. Cellular uptake and targeting capability of conjugated samples were further investigated by confocal microscopy and the conjugated curcumin nanostructures showed an enhanced efficacy compared to curcumin. Furthermore, flow cytometry analysis proved that early apoptosis occurred in HCT116 cell line, after 24 h incubation with conjugated curcumin.

Cationic albumin-conjugated chelating agent as a novel brain drug delivery system in neurodegeneration.

The critical role of metal ions and in particular iron in oxidative stress and protein aggregation offers chelation therapy as a sensible pharmaceutical strategy in oxidative stress-induced neuronal damages. In this research, we conjugated an iron-chelating agent, deferasirox, to cationized human serum albumin molecules in order to develop a novel brain delivery system for the management of neurodegenerative disorders due to the significant role of oxidative stress-induced neuronal injury in such diseases. Cationized albumin is known to be able to transport to brain tissue via adsorptive-mediated transcytosis. The developed structures were molecularly characterized, and their conjugation ratio was determined. PC12 cell line was utilized to evaluate the neuroprotective features of these newly developed molecules in the presence of hydrogen peroxide neuronal damage and to identify the mechanisms behind the observed neuronal protection including apoptotic and autophagic pathways. Furthermore, a rat model of Alzheimer's disease was utilized to evaluate the impact of conjugated structures in vivo. Data analysis revealed that the conjugated species were able to hinder apoptotic cell death while enhancing autophagic process. The developed conjugated species were also able to attenuate amyloid beta-induced learning deficits when administered peripherally.