Key Features in the Design and Function of Nanocarriers for Intranasal Administration of Gene Therapy in Huntington Disease.

A major obstacle to fulfilling the therapeutic promise of gene therapies for hereditary brain diseases, such as Huntington' Disease (HD), is the requirement for viral vectors and/or an invasive delivery system (stereotaxic injection into brain or infusion into the intrathecal space). HD is an autosomal dominant neurodegenerative disease for which several clinical trials have demonstrated gene-lowering effects following intrathecal administration. These technical limitations have given impetus to the development of alternative non-invasive delivery systems for gene therapy of brain diseases. The overall objective of this review is to discuss the key features in the design of nanocarriers for intranasal administration of gene-therapy for HD, focusing primarily on our series of published work on the use of nanocarriers for gene therapy. Design and development of nanocarriers packaged with gene-lowering agents represents a significant advance towards non-invasive nose-to-brain delivery of gene therapy for HD and other hereditary brain disorders.

Multi-Targeting Intranasal Nanoformulation as a Therapeutic for Alzheimer's Disease.

Melatonin, insulin, and Δ9-tetrahydrocannabinol (THC) have been shown to reverse cognitive deficits and attenuate neuropathologies in transgenic mouse models of Alzheimer's disease (AD) when used individually. Here, we evaluated the therapeutic properties of long-term intranasal treatment with a novel nanoformulation containing melatonin, insulin, and THC in aged APPswe/PS1ΔE9 (APP/PS1) mice, a transgenic model of AD. Transgenic mice at the age of 12 months were intranasally administered with a new nanoformulation containing melatonin, insulin, and THC at doses of 0.04, 0.008, and 0.02 mg/kg, respectively, once daily for 3 months. The spatial memory of the mice was assessed using the radial arm water maze (RAWM) test before and after drug treatment. Brain tissues were collected at the end of the treatment period for the assessment of Aß load, tauopathy state, and markers of mitochondrial function. The RAWM test revealed that the treatment with the melatonin-insulin-THC (MIT) nasal spray improved the spatial learning memory of APP/PS1 mice significantly. Results of protein analyses of brain homogenates indicated that MIT treatment significantly decreased the tau phosphorylation implicated in tau toxicity (p < 0.05) and the expression of CKMT1 associated with mitochondrial dysfunction. Moreover, MIT significantly decreased the expression of two mitochondrial fusion-related proteins, Mfn2 and Opa1 (p < 0.01 for both), while increasing the expression of a mitophagy regulator, Parkin, suggesting a compensatory enhancement of mitophagy due to MIT-promoted mitochondrial fusion. In conclusion, this study was the first to demonstrate the ability of an MIT nanoformulation to improve spatial memory in AD mice through its multi-targeting effects on Aß production, tau phosphorylation, and mitochondrial dynamics. Thus, MIT may be a safe and effective therapeutic for AD.

Measurement of Δ9THC and metabolites in the brain and peripheral tissues after intranasal instillation of a nanoformulation.

BACKGROUND: Comparative bioavailability of cannabinoids following their administration by dosing routes has been studied previously, but there are no quantitative reports of distribution of Δ9THC, nor its metabolites, across various brain regions following intranasal (i.n.) administration. The aim of the present study was to determine the time course of Δ9THC transport from nose to brain and to quantify the distribution of Δ9THC and its metabolites in four brain regions. METHODS: Δ9THC was formulated as a lipophilic nano-emulsion and instilled i.n. to three groups of adult mice and euthanized after 2, 4, and 8 h. Brains were dissected into 4 regions. Sensitive analytical methods (HPLC-MS) were utilized to quantify levels of Δ9THC and metabolites in brain regions and peripheral tissues. Data was expressed as mean concentrations (± SEM) of Δ9THC and metabolites in brain regions, blood, plasma, urine, and liver. Two-way analysis of variance was performed followed by post hoc multiple comparisons. RESULTS: Peak concentrations of Δ9THC were reached at 2 h in the brain (15.9 ng/mg), blood (4.54 µg/mL), and plasma (4.56 µg /mL). The percentage of administered dose of Δ9THC transported to the brain (5.9%) was greater than in blood (1.7%), plasma (1.6%), urine (0.4%), and liver (0.1%). Concentrations of Δ9THC and its THC-COOH metabolite in the liver reached their highest levels at 8 h. DISCUSSION: The present study is the first to report the uptake and distribution across brain regions of Δ9THC and its principal metabolites following i.n. administration. The systemic bioavailability (absorption into the blood) of intranasal Δ9THC was 1.7% of the administered dose, much lower than that reported by others after oral ingestion (7-10%) and inhalation (20-35%), but those prior studies did not measure the transport of Δ9THC into brain regions. Others have reported Δ9THC in the whole brain following i.n. instillation in a different species (rats) to be twice (5.9%) that following i.p. injections, while metabolites of Δ9THC in rat brain were lower after i.n. administration. CONCLUSIONS: The intranasal route of a Δ9THC nanoformulation is an effective way to deliver cannabinoids to the brain, especially in those who cannot take the medication orally. Going forward, a metered dosing nasal spray will provide accurate and consistent doses.

Dual-function hybrid nanoparticles with gene silencing and anti-inflammatory effects.

Background: Nanocarriers loaded with siRNA can be administered intranasally to provide a noninvasive, safe alternative to direct intracerebral or intrathecal infusions. Dual-function nanocarriers can also be designed to deliver several payloads that address different components of the pathological process. Aim: To design and test a hybrid nanocarrier with the capacity to lower Huntington's Disease gene (HTT) expression and prevent or diminish inflammation. Methods: Novel hybrid nanoparticles were fabricated using a chitosan-based matrix core loaded with siRNA and an outer shell consisting of a lipid composition containing cannabidiol. Results: Incubation of hybrid nanoparticles in mesenchymal stem cell cultures obtained from a YAC128 transgenic mouse modeling Huntington's disease resulted in effective lowering of mutant HTT gene expression and reduced levels of expression of the proinflammatory cytokine IL-6. Conclusion: A novel hybrid nanocarrier system with dual actions is effective in lowering HTT gene expression and attenuating inflammatory processes.

The Memory Benefit to Aged APP/PS1 Mice from Long-Term Intranasal Treatment of Low-Dose THC.

THC has been used as a promising treatment approach for neurological disorders, but the highly psychoactive effects have largely warned off many scientists from pursuing it further. We conducted an intranasal treatment using low-dose THC on 12-month-old APP/PS1 mice daily for 3 months to overcome any potential psychoactive response induced by the systemic delivery. Our results demonstrate that the THC nasal treatment at 0.002 and 0.02 mg/kg significantly slowed the memory decline compared to that in the vehicle-treated transgenic mouse control group. An enzyme-linked immunosorbent assay showed that the Aß1-40 and 1-42 peptides decreased in the THC-treated groups. The Western blot data indicate that long-term low-dose THC intranasal administration promoted p-tau level reduction and mitochondrial function marker redistribution. The blood biochemical parameter data demonstrate some insignificant changes in cytokine, immunoglobulin, and immune cell profiles during intranasal THC treatment. Intranasal delivery is a non-invasive and convenient method that rapidly targets therapeutics to the brain, minimizing systemic exposure to avoid unwanted adverse effects. Our study provides new insights into the role of low-dose THC intranasal treatment as a pharmacological strategy to counteract alterations in Alzheimer's disease-related cognitive performance.

Data on enrichment of chitosan nanoparticles for intranasal delivery of oligonucleotides to the brain.

Data on preparation and characterization of chitosan-based nanoparticles (NP) carrying small interfering RNA (siRNA) for non-invasive gene therapy is presented. Polyelectrolyte complexation method was carried out in diluted concentrations to obtain relatively small (less than 200 nm) NP. To provide substantial dose of siRNA within tolerable volume of intranasal administration the NP were subjected to enrichment process. Offered here NP fabrication does two steps process comprise provisional and enriched preparations? The differences between these preparations were analyzed with hydrodynamic size distribution and zeta potential measurements. The effect of siRNA lipophilicity on NP physical instability was also tested. Biological evaluation of nanoparticles is described in our published article [1].

Enriched chitosan nanoparticles loaded with siRNA are effective in lowering Huntington's disease gene expression following intranasal administration.

Therapies to lower gene expression in brain disease currently require chronic administration into the cerebrospinal fluid (CSF) by intrathecal infusions or direct intracerebral injections. Though well-tolerated in the short-term, this approach is not tenable for a life-time of administration. Nose-to-brain delivery of enriched chitosan-based nanoparticles loaded with anti-HTT siRNA was studied in a transgenic YAC128 mouse model of Huntington's Disease (HD). A series of chitosan-based nanoparticle (NP) formulations encapsulating anti-HTT small interfering RNA (siRNA) was designed to protect the payload from degradation "en route" to the target. Factors to improve production of effective nanocarriers of anti-HTT siRNA were identified and tested in a YAC128 mouse model of Huntington's disease. Four formulations of nanocarriers were identified to be effective in lowering HTT mRNA expression by at least 50%. Intranasal administration of nanoparticles carrying siRNA is a promising therapeutic alternative for safe and effective lowering of mutant HTT expression.

Optimizing Nanoparticle Design for Gene Therapy: Protection of Oligonucleotides from Degradation Without Impeding Release of Cargo.

Gene therapy delivery systems that rely on synthetic nanocarriers can be optimized by assays of nucleic acid protection and kinetic studies of nucleic acid release. These empirical measurements ensure nanoparticle stability and predict potential in vivo efficacy. Quantitative methods for assessment of the capacity of nanoparticles to protect oligonucleotide cargo and to measure the rate of release of the cargo were developed and tested based on six commercial cationic matrices. in vitro study of drug release kinetics provides predictable release rates under a variety of conditions which can be adapted to appropriate physiological factors that affect release in vivo. In brief, in vitro DNA release and DNase I degradation assays described here will be useful for optimization of nanocarrier-mediated gene therapy administration by various routes.