Safety, Tolerability, Pharmacokinetics, and Food Effects on TAC-302 in Healthy Participants: Randomized, Double-Blind, Placebo-Controlled, Single-Dose and Multiple-Dose Studies.

TAC-302 stimulates neurite outgrowth activity and is expected to restore urinary function in patients with lower urinary tract dysfunction. We conducted 2 phase 1, randomized, placebo-controlled studies to confirm the safety and pharmacokinetics (PK) of TAC-302 in healthy adult Japanese male volunteers. In the first-in-human single-dose study (n = 60), TAC-302 was administered at doses from 100 to 1200 mg after an overnight fast. The effects of a meal on the PK of TAC-302 400 mg were also examined. A multiple-dose study (n = 36) evaluated the effects of meal fat content on the PK of single doses of TAC-302 (100, 200, or 400 mg) and multiple doses of TAC-302 administered for 5 days (100, 200, and 400 mg twice daily). TAC-302 showed linear PK up to doses of 1200 mg in the fasting state, and across the dose range of 100-400 mg in the fed state. No accumulation of TAC-302 was observed. Food, particularly with high fat content, increased TAC-302 plasma concentrations. No differences were observed in the adverse event incidence between the TAC-302 and placebo groups in either study. TAC-302 showed a wide safety margin.

Pharmacokinetics and tissue distribution of neurotrophin 3 after intracochlear delivery.

Neurotrophin therapy has potential to reverse some forms of hearing loss. However, cochlear pharmacokinetic studies are challenging due to small fluid volumes. Here a radioactive tracer was used to determine neurotrophin-3 retention, distribution and clearance after intracochlear administration. 125I-neurotrophin-3 was injected into guinea pig cochleae using a sealed injection technique comparing dosing volumes, rates and concentrations up to 750 µg/mL. Retention was measured by whole-cochlear gamma counts at five time points while distribution and clearance were assessed by autoradiography. Smaller injection volumes and higher concentrations correlated with higher retention of neurotrophin-3. Distribution of neurotrophin-3 was widespread throughout the cochlear tissue, decreasing in concentration from base to apex. Tissue distribution was non-uniform, with greatest density in cells lining the scala tympani and lower density in neural target tissue. The time constant for clearance of neurotrophin-3 from cochlear tissues was 38 h but neurotrophin-3 remained detectable for at least 2 weeks. Neurotrophin-3 was evident in the semi-circular canals with minor spread to the contralateral cochlea. This study is the first comprehensive evaluation of the disposition profile for a protein therapy in the cochlea. The findings and methods in this study will provide valuable guidance for the development of protein therapies for hearing loss.

Targeting delivery of liposomes with conjugated p-aminophenyl-α-d-manno-pyranoside and apolipoprotein E for inhibiting neuronal degeneration insulted with ß-amyloid peptide.

Liposomes with conjugated p-aminophenyl-α-d-manno-pyranoside (APMP) and apolipoprotein E (ApoE) (APMP-ApoE-liposomes) were employed to carry neuron growth factor (NGF) across the blood-brain barrier (BBB) and enhance the survival of degenerated neurons. APMP-ApoE-liposomes were used to deliver NGF across a monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes (HAs) for rescuing SK-N-MC cells from an insult of ß-amyloid peptide 1-42 (Aß1-42). An increase in the APMP concentration enhanced the particle size, HBMEC and HA viability, permeability for propidium iodide (PI), and permeability for NGF, however, reduced the absolute value of zeta potential, APMP conjugation efficiency and transendothelial electrical resistance (TEER). In addition, an increase in the ApoE concentration increased the particle size, absolute value of zeta potential, HBMEC and HA viability, permeability for PI, permeability for NGF and SK-N-MC cell viability, however, decreased the ApoE conjugation efficiency and TEER. APMP and ApoE on liposomes can be promising surface moieties to carry NGF across the BBB, target degenerated neurons and inhibit Aß1-42-induced neurotoxicity in Alzheimer's disease.

Retinal ganglion cell polarization using immobilized guidance cues on a tissue-engineered scaffold.

Cell transplantation therapies to treat diseases related to dysfunction of retinal ganglion cells (RGCs) are limited in part by an inability to navigate to the optic nerve head within the retina. During development, RGCs are guided by a series of neurotrophic factors and guidance cues; however, these factors and their receptors on the RGCs are developmentally regulated and often not expressed during adulthood. Netrin-1 is a guidance factor capable of guiding RGCs in culture and relevant to guiding RGC axons toward the optic nerve head in vivo. Here we immobilized Netrin-1 using UV-initiated crosslinking to form a gradient capable of guiding the axonal growth of RGCs on a radial electrospun scaffold. Netrin-gradient scaffolds promoted both the percentage of RGCs polarized with a single axon, and also the percentage of cells polarized toward the scaffold center, from 31% to 52%. Thus, an immobilized protein gradient on a radial electrospun scaffold increases RGC axon growth in a direction consistent with developmental optic nerve head guidance, and may prove beneficial for use in cell transplant therapies for the treatment of glaucoma and other optic neuropathies.

Safety and pharmacokinetics of escalating doses of human recombinant nerve growth factor eye drops in a double-masked, randomized clinical trial.

BACKGROUND AND OBJECTIVES: Nerve growth factor (NGF) is a neurotrophin with therapeutic possibilities that extend from the nervous system to the eye. We tested the safety, maximal tolerated dose, pharmacokinetics, and antigenicity of a novel human recombinant NGF (rhNGF) eye-drop formulation in a phase I study. METHODS: This prospective, randomized, double-masked, vehicle-controlled trial, sponsored by Dompé SpA (registered as NCT01744704 at ClinicalTrials.gov), enrolled 74 healthy volunteers (24 females, 50 males, age 40.2 ± 11.8 years). Subjects were randomized in three cohorts to receive (1) a single eye-drop containing 0.0175, 0.175, or 0.7 µg rhNGF; (2) a single ascending dose of rhNGF eye drops three times a day for 1 day (total daily dose 2.1, 6.3, or 18.9 µg), or vehicle; or (3) a multiple ascending dose of rhNGF eye drops three times a day for 5 days (total dose 10.5, 31.5, or 94.5 µg), or vehicle. Outcome measures included blood chemistry, urinalyses, vital signs, electrocardiograms (ECGs), serum NGF antibodies, ocular and systemic adverse events (AEs), visual acuity, tear function, intraocular pressure, fundus oculi, and ocular symptoms. RESULTS: Administration of rhNGF eye drops did not result in a significant increase of circulating NGF levels and no antidrug antibodies were detected in serum. No serious AEs were recorded, and a few mild, transient ocular AEs related to rhNGF administration were reported only at the highest concentration. CONCLUSIONS: rhNGF eye drops were well tolerated, with no detectable clinical evidence of systemic AEs. These results pave the way for the development of clinical trials on rhNGF in ophthalmology.

Psicofarmacología y trastornos afectivos / No disponible

La depresión mayor es uno de los trastornos afectivos con mayor prevalencia en clínica. A pesar de todos los procesos neurobiológicos implicados en esta patología, el tratamiento actual de la depresión se centra en los neurotransmisores NA y 5Ht a nivel de sistema nervioso central, y en menor medida, dopamina. el tratamiento con antidepresivos y su respuesta requiere una revaloración sistemática del paciente debido a que existe un 25 % de la población que no responde al tratamiento con estos fármacos, del 26-50 % responden solo parcialmente y tan solo un 50 % responde favorablemente, o al menos, disminuyen significativamente los síntomas más graves de la enfermedad. Las estrategias usadas en pacientes resistentes a la depresión, consiste en la administración de otros agentes en combinación con antidepresivos para aumentar su efecto. La depresión es característica no solo por ser un trastorno afectivo sino que posee una dimensión somática caracterizada por la pérdida de peso, fatiga, trastornos del sueño, dolores de cabeza y estómago y otros síntomas de dolor. La teoría que explica la prevalencia de estas enfermedades se basa en el hecho de que ambas patologías comparten sustratos neurobiológicos como, por ejemplo, ocurre en el caso de los neurotransmisores implica-dos en la depresión (5Ht y NA) que, a su vez, juegan un papel fundamental en la modulación del dolor. La hipótesis neurotrófica de la depresión es otra hipótesis más reciente (que postula una disminución en la producción de nuevas neuronas en el giro dentado del hipocampo) está relacionada con la etiopatogenia de la depresión. Varios estudios han demostrado que la mayoría de los antidepresivos estimulan la neurogénesis en el giro dentado del hipocampo

Major depression is one of the affective disorders with higher prevalence in clinical. Although major depression comprises many neurobiological pro cesses, the current treatment is focusing in the increase of NA and 5Ht neurotransmitters in the cNS, and even less dopamine. Both treatment and response of patients to antidepressants require high monitoring due to the fact that 25 % of population result resistant to the treatment, 25-50 % respond partially and only the 50 % improve the symptom of depression. Another pharmacological strategies used in patients resistant to depression, involves the administration of other agents in combination with antidepressants to enhance their effect. Depression is widely known by its affective component characterized by moods, feelings of worthless-ness, diminished interest in pleasurable stimuli, and impaired decision-making abilities, although it can also have a somatic dimension characterized by weight change, fatigue, sleep disturbances, and pain. the prevalence of pain in major depression is a common situation in clinical. According to the earlier theories, the presence of pain symptoms in depression is due to the fact that both pathologies share neuroanatomical substrates such as the neurotransmitter involved in depression (NA and 5Ht) which play an important role in the modulation of pain. Major depression have been explained for many theories, one of the most important at the present is called «the neurotropic hypothesis of depression» which postulates that the production of new neurons in the dentate gyrus of the hippocampus is related to the pathogenesis of depression and accordingly to this theory, many studies have demonstrated an increase of neurogenesis in the hippocampus after antidepressant treatment

Phosphomimetic mutants of pigment epithelium-derived factor with enhanced anti-choroidal melanoma cell activity in vitro and in vivo.

PURPOSE: Currently, choroidal melanoma is chemoresistant and there is no routine adjuvant chemotherapy for it. We investigated whether pigment epithelium-derived factor (PEDF) and its triple phosphomimetic mutants could more efficiently suppress melanoma tumor growth and metastasis, as well as how the triple phosphomimetic mutants act as antitumor agents. METHODS: Phosphomimetic mutants of PEDF were constructed by site mutagenesis. Lentiviruses carrying wild type (WT) PEDF, S24E114E227A (EEA)-PEDF, and S24E114E227E (EEE)-PEDF were produced in 293 fast-growing, highly transfectable (FT) cells and used to infect human choroidal melanoma cell line (OCM-1). The growth, migration, invasion and metastasis abilities of OCM-1 cells expressing WT-PEDF, EEA-PEDF or EEE-PEDF were investigated in vitro and in vivo, while the underlying mechanism of PEDF phosphomimetic mutants were investigated via Western blotting. RESULTS: OCM-1 cells infected with lentiviruses carrying WT-PEDF, EEA-PEDF, and EEE-PEDF displayed reduced proliferation, migration and invasion abilities, and were more prone to apoptosis. Cell media containing WT-PEDF, EEA-PEDF, or EEE-PEDF protein inhibited the tube forming capacity of human umbilical vein endothelial cells (HUVEC) in vitro. OCM-1 cells expressing WT-PEDF, EEA-PEDF, or EEE-PEDF displayed significantly reduced tumor growth and metastasis in the melanoma xenograft of nude mice models, with the PEDF mutants displaying much stronger effects than the wild type. The antitumor effects of PEDF are associated with the inhibition of VEGF and nuclear factor kappa-B (NF-κB) expression, as well as further inhibition of Akt phosphorylation. CONCLUSIONS: The phosphomimetic mutants of PEDF showed enhanced anti-melanoma activity by directly affecting tumor cells and indirectly affecting angiogenesis. These findings encourage the development of PEDF mutants as innovative anticancer agents.

Encapsulated cell biodelivery of nerve growth factor to the Basal forebrain in patients with Alzheimer's disease.

BACKGROUND/AIMS: Degeneration of cholinergic neurons in the basal forebrain correlates with cognitive decline in patients with Alzheimer's disease (AD). Targeted delivery of exogenous nerve growth factor (NGF) has emerged as a potential AD therapy due to its regenerative effects on the basal forebrain cholinergic neurons in AD animal models. Here we report the results of a first-in-man study of encapsulated cell (EC) biodelivery of NGF to the basal forebrain of AD patients with the primary objective to explore safety and tolerability. METHODS: This was an open-label, 12-month study in 6 AD patients. Patients were implanted stereotactically with EC-NGF biodelivery devices targeting the basal forebrain. Patients were monitored with respect to safety, tolerability, disease progression and implant functionality. RESULTS: All patients were implanted successfully with bilateral single or double implants without complications or signs of toxicity. No adverse events were related to NGF or the device. All patients completed the study, including removal of implants at 12 months. Positive findings in cognition, EEG and nicotinic receptor binding in 2 of 6 patients were detected. CONCLUSIONS: This study demonstrates that surgical implantation and removal of EC-NGF biodelivery to the basal forebrain in AD patients is safe, well tolerated and feasible.

Intranasal administration: a potential solution for cross-BBB delivering neurotrophic factors.

Neurotrophic factors (NTFs) are endogenous polypeptides that regulate the growth, survival, differentiation, and functioning of neurons. The neuroprotective effects of NTFs in experimental animals give strong rationale for developing therapies for neurological disorders. However, when NTFs are applied in clinical trials, great expectation leads to equal disappointment. NTFs are large molecular-weighted and hydrophilic proteins, which limits their access to the central nervous system (CNS) after systemic administration, principally due to poor blood-brain barrier (BBB) permeability and unfavorable pharmacokinetic profiles. Although intracerebral infusion may transport NTFs into the CNS, the invasiveness limits its clinical application. Intranasal administration has been under research for decades and presents promising outcomes in preclinical studies for brain delivering of NTFs. After intranasal delivery, NTFs gain direct and quick access into the CNS at concentrations high enough to elicit their biological effects, bypassing the BBB and minimizing systemic exposure. Due to its invasiveness and convenience, intranasal delivery is feasible for NTFs administration. Although direct evidence of nose-to-brain pathway in human is lacking due to ethical problems, the existence of the nose-to-cerebral spinal fluid pathway has been verified in men. Furthermore, there is abundant indirect evidence for the nose-to-brain pathway as determined by the efficacy of intranasally administered neuroproteins, such as insulin, oxytocin, and vasopressin in clinical trials. Based on the solid preclinical research supporting the efficacy of intranasal NTFs, and the successful clinical application of neuroproteins (not NTFs), it is time to evaluate clinical application of NTFs in treating both acute and chronic CNS diseases.

New approaches to bridge nerve gaps: development of a novel drug-delivering nerve conduit.

Contemporary bridging techniques for repairing nerve gaps caused by trauma require autologous nerve grafts, which are difficult to harvest and handle and result in significant donor site deficit. Several nerve conduits with axon growth-enhancing potential have been proposed, developed and tested over the past fifteen years. In this work, prototypes of a nerve conduit designed to bridge large nerve gaps (≥10mm) end-to-end were incorporated with concentric drug reservoirs for constant and controlled drug delivery to enhance axon growth. These devices were designed, fabricated and tested in vitro in amber glass vials with bovine serum albumin in order to determine the drug release kinetics for future application. Our devices have shown the capability to deliver the drug of interest over a 6-day period.

Intranasal delivery of neurotrophic factors BDNF, CNTF, EPO, and NT-4 to the CNS.

Injury to the central nervous system (CNS) generally results in significant neuronal death and functional loss. In vitro experiments have demonstrated that neurotrophic factors such as brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and neurotrophin-4/5 (NT-4/5) can promote neuronal survival. However, delivery to the injured CNS is difficult as these large protein molecules do not efficiently cross the blood-brain barrier. Intranasal delivery of 70 microg [(125)I]-radiolabeled BDNF, CNTF, NT-4, or erythropoietin (EPO) resulted in 0.1-1.0 nM neurotrophin concentrations within 25 min in brain parenchyma. In addition, not only did these neurotrophic factors reach the CNS, they were present in sufficient concentrations to activate the prosurvival PI3Kinase/Akt pathway, even where lower levels of neurotrophic factors were measured. Currently traumatic, ischemic and compressive injuries to the CNS have no effective treatment. There is potential clinical relevancy of this method for rescuing injured CNS tissues in order to maintain CNS function in affected patients. The intranasal delivery method has great clinical potential due to (1) simplicity of administration, (2) noninvasive drug administration, (3) relatively rapid CNS delivery, (4) ability to repeat dosing easily, (5) no requirement for drug modification, and (6) minimal systemic exposure.

Controlled nerve growth factor release from multi-ply alginate/chitosan-based nerve conduits.

The delivery kinetics of growth factors has been suggested to play an important role in the regeneration of peripheral nerves following axotomy. In this context, we designed a nerve conduit (NC) with adjustable release kinetics of nerve growth factor (NGF). A multi-ply system was designed where NC consisting of a polyelectrolyte alginate/chitosan complex was coated with layers of poly(lactide-co-glycolide) (PLGA) to control the release of embedded NGF. Prior to assessing the in vitro NGF release from NC, various release test media, with and without stabilizers for NGF, were evaluated to ensure adequate quantification of NGF by ELISA. Citrate (pH 5.0) and acetate (pH 5.5) buffered saline solutions containing 0.05% Tween 20 yielded the most reliable results for ELISA active NGF. The in vitro release experiments revealed that the best results in terms of reproducibility and release control were achieved when the NGF was embedded between two PLGA layers and the ends of the NC tightly sealed by the PLGA coatings. The release kinetics could be efficiently adjusted by accommodating NGF at different radial locations within the NC. A sustained release of bioactive NGF in the low nanogram per day range was obtained for at least 15days. In conclusion, the developed multi-ply NGF loaded NC is considered a suitable candidate for future implantation studies to gain insight into the relationship between local growth factor availability and nerve regeneration.

Ligand-bound quantum dot probes for studying the molecular scale dynamics of receptor endocytic trafficking in live cells.

Endocytic receptor trafficking is a complex, dynamic process underlying fundamental cell function. An integrated understanding of endocytosis at the level of single or small numbers of ligand bound-receptor complexes inside live cells is currently hampered by technical limitations. Here, we develop and test ligand nerve growth factor-bound quantum dot (NGF-QD) bioconjugates for imaging discrete receptor endocytic events inside live NGF-responsive PC12 cells. Using single particle tracking, QD hybrid gel coimmunoprecipitation, and immuno-colocalization, we illustrate and validate the use of QD-receptor complexes for imaging receptor trafficking at synchronized time points after QD-ligand-receptor binding and internalization (t = 15-150 min). The unique value of these probes is illustrated by new dynamic observations: (1) that endocytosis proceeds at strikingly regulated fashion, and (2) that diffusive and active forms of transport inside cells are rapid and efficient. QDs are powerful intracellular probes that can provide biologists with new capabilities and fresh insight for studying endocytic receptor signaling events, in real time, and at the resolution of single or small numbers of receptors in live cells.

Conventional kinesin-I motors participate in the anterograde axonal transport of neurotrophins in the visual system.

Retinal ganglion cells (RGCs) anterogradely transport neurotrophins to the midbrain tectum/superior colliculus with significant downstream effects. The molecular mechanism of this type of axonal transport of neurotrophins is not well characterized. We identified kinesin-I proteins as a motor participating in the anterograde axonal movement of vesicular structures containing radiolabeled neurotrophins along the optic nerve. RT-PCR analysis of purified murine RGCs showed that adult RGCs express all known members of the kinesin-I family. After intraocular injection of (125)I-brain-derived neurotrophic factor (BDNF) into the adult mouse or (125)I-neurotrophin-3 (NT-3) into the embryonic chicken eye, radioactivity was efficiently immunoprecipitated from the optic nerve lysates by anti-kinesin heavy chain and anti-kinesin light chain monoclonal antibodies (H2 and L1). Immunoreactivity for the BDNF receptor trkB is also present in the immunoprecipitates obtained by the anti-kinesin-I antibodies. The delivery of the H2 antibody in vivo into the mouse RGCs substantially reduced anterograde axonal transport of (125)I-BDNF. Anterograde transport of BDNF was not diminished in kinesin light chain 1 (KLC1) knockout mice. However, this may be due to redundancy in functions between two different isoforms of KLC present in the RGCs, as it was described previously for kinesin heavy chains (Kanai et al. [ 2000] J Neurosci 20:6374-6384). These data indicate that kinesin-I is a protein motor that participates in the anterograde axonal transport of neurotrophins in the chicken and mouse visual pathways.

Intracerebral infusion of neurotrophic factors.

Neurotrophic factors are among the most potent neuroprotective and neuroregenerative agents known. However, they cross the adult mammalian blood-brain barrier very poorly and can have serious peripheral side effects. These problems can be solved by using chronic infusions with small pumps to directly deliver known quantities of these proteins into selected regions of the brains of small experimental animals such as rats and mice. The method consists of commercially available Alzet osmotic pumps that are placed under the skin and are connected to commercially available metal infusion cannulas whose tip can be stereotactically placed in virtually any location of the brain. Different models of pumps that fit comfortably in rodents can be selected for infusion between 1 and 28 days and at infusion rates ranging between 8 and 0.25 microL/h, respectively. Methodological details are provided for the successful use of proteins and to minimize the time of the surgery.

Pharmacokinetics and biodistribution of a small radioiodine labeled nerve growth factor fragment.

Nerve growth factor (NGF) exerts various actions on neuronal and non-neuronal tissues and has potential therapeutic utility, but difficulties in using the whole protein have stimulated interest in small NGF fragments. We radioiodinated a small cyclic peptide derived from NGF using the Bolton-Hunter method [125I-C(92-96)], and confirmed binding to high affinity NGF receptors by cross-linkage analysis. Pharmacokinetic characteristics in intravenously injected mice were T 1/2 alpha 5.2 min, T 1/2beta 121.3 min, clearance 11.8+/-0.5 ml/min, and volume of distribution 69.7+/-4.6 ml. Dose-proportionate increases in areas-under-curve and peak-concentrations indicated linear pharmacokinetics. Biodistribution data revealed that clinically relevant doses allowed C(92-96) accumulation sufficient to elicit biological responses in receptor expressing organs including the lungs, liver, spleen, and pancreas.

Inner ear therapy for neural preservation.

A gradual loss of auditory neurons often occurs following sensorineural hearing loss. Since the cochlear implant must stimulate the remaining auditory neuron population, it would be beneficial to preserve as many auditory neurons as possible. Neurotrophic factors protect auditory neurons from degradation after sensorineural hearing loss in experimental animals, but have not yet been translated into the clinical setting. Current experimental and clinical techniques for drug delivery to the inner ear are examined in this review, covering the routes for drug delivery to the cochlea and the delivery systems used to introduce them. Duration of treatment, drug diffusion, effectiveness and safety are discussed with references to how they may be translated to the implementation of neurotrophic factor treatment for neural preservation.

Stimulation of neurite outgrowth by neurotrophins delivered from degradable hydrogels.

Degradable hydrogels are useful vehicles for the delivery of growth factors to promote the regeneration of diseased or damaged tissue. In the central nervous system, there are many instances where the delivery of neurotrophins has great potential in tissue repair, especially for treatment of spinal cord injury. In this work, hydrogels based on poly(ethylene glycol) that form via a photoinitiated polymerization were investigated for the delivery of neurotrophins. The release kinetics of these factors are controlled by changes in the network crosslinking density, which influences neurotrophin diffusion and subsequent release from the gels with total release times ranging from weeks to several months. The release and activity of one neurotrophic factor, ciliary-neurotrophic factor (CNTF), was assessed with a cell-based proliferation assay and an assay for neurite outgrowth from retinal explants. CNTF released from a degradable hydrogel above an explanted retina was able to stimulate outgrowth of a significantly higher number of neurites than controls without CNTF. Finally, unique microsphere/hydrogel composites were developed to simultaneously deliver multiple neurotrophins with individual release rates.

Transport of nerve growth factor encapsulated into liposomes across the blood-brain barrier: in vitro and in vivo studies.

A nerve growth factor (NGF) was encapsulated into liposomes in order to protect it from the enzyme degradation in vivo and promote it permeability across the blood-brain barrier (BBB). RMP-7, a ligand to the B2 receptor on brain microvascular endothelial cells (BMVEC), was combined with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethylenegly-col)]-hydroxy succinamide (DSPE-PEG-NHS) to obtain DSPE-PEG-RMP-7. Then DSPE-PEG-RMP-7 was incorporated into the liposomes' surface to target sterically stabilized liposomes (SSL-T) to the brain. The highest percent of NGF encapsulated into liposomes was about 34%, and the average size of liposomes was below 100 nm. A primary model of BBB was established and evaluated by morphological, permeability, and transendothelial electrical resistance (TEER). The BBB model was employed to study the permeability of NGF liposomes in vitro. The results indicated that the liposomes could enhance transport of NGF across the BBB. The best transport rate was received with NGF-SSL-T. The brain distribution of NGF liposomes was studied in vivo, the amount of NGF in the brain was increased in the order: NGF-SSL-T>NGF-SSL+RMP-7>NGF-SSL>NGF-L. The maximum concentration of NGF was recorded in 30 min following the intravenous injection. In particular, a majority of NGF was distributed in striatum, hippocampus and cortex, and the concentration of NGF was relatively lower in olfactory bulb, cerebellum and brain stem. There was a close relationship between P(e) (permeability coefficient on in vitro BBB model) and T(e) (brain targeted coefficient in vivo) for NGF encapsulated into the liposomes.

GDNF delivery using human neural progenitor cells in a rat model of ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of spinal cord, brainstem, and cortical motor neurons. In a minority of patients, the disease is caused by mutations in the copper (2+)/zinc (2+) superoxide dismutase 1 (SOD1) gene. Recent evidence suggests that astrocytes are dysfunctional in ALS and may be a critical link in the support of motor neuron health. Furthermore, growth factors, such as glial cell line-derived neurotrophic factor (GDNF), have a high affinity for motor neurons and can prevent their death following various insults, but due to the protein's large size are difficult to directly administer to brain. In this study, human neural progenitor cells (hNPC) isolated from the cortex were expanded in culture and modified using lentivirus to secrete GDNF (hNPC(GDNF)). These cells survived up to 11 weeks following transplantation into the lumbar spinal cord of rats overexpressing the G93A SOD1 mutation (SOD1 (G93A)). Cellular integration into both gray and white matter was observed without adverse behavioral effects. All transplants secreted GDNF within the region of cell survival, but not outside this area. Fibers were seen to upregulate cholinergic markers in response to GDNF, indicating it was physiologically active. We conclude that genetically modified hNPC can survive, integrate, and release GDNF in the spinal cord of SOD1 (G93A) rats. As such, they provide an interesting source of cells for both glial replacement and trophic factor delivery in future human clinical studies.