Alzheimers Research Center at Regions Hospital

Saint Paul, MN, United States

Alzheimers Research Center at Regions Hospital

Saint Paul, MN, United States
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Dhuria S.V.,University of Minnesota | Dhuria S.V.,Alzheimers Research Center at Regions Hospital | Hanson L.R.,Alzheimers Research Center at Regions Hospital | Frey II W.H.,University of Minnesota | Frey II W.H.,Alzheimers Research Center at Regions Hospital
Journal of Pharmaceutical Sciences | Year: 2010

The blood-brain barrier (BBB) limits the distribution of systemically administered therapeutics to the central nervous system (CNS), posing a significant challenge to drug development efforts to treat neurological and psychiatric diseases and disorders. Intranasal delivery is a noninvasive and convenient method that rapidly targets therapeutics to the CNS, bypassing the BBB and minimizing systemic exposure. This review focuses on the current understanding of the mechanisms underlying intranasal delivery to the CNS, with a discussion of pathways from the nasal cavity to the CNS involving the olfactory and trigeminal nerves, the vasculature, the cerebrospinal fluid, and the lymphatic system. In addition to the properties of the therapeutic, deposition of the drug formulation within the nasal passages and composition of the formulation can influence the pathway a therapeutic follows into the CNS after intranasal administration. Experimental factors, such as head position, volume, and method of administration, and formulation parameters, such as pH, osmolarity, or inclusion of permeation enhancers or mucoadhesives, can influence formulation deposition within the nasal passages and pathways followed into the CNS. Significant research will be required to develop and improve current intranasal treatments and careful consideration should be given to the factors discussed in this review. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

Liu Z.,Ford Motor Company | Li Y.,Ford Motor Company | Zhang L.,Ford Motor Company | Xin H.,Ford Motor Company | And 5 more authors.
Neurobiology of Disease | Year: 2012

As a thrombolytic agent, application of recombinant tissue plasminogen activator (tPA) to ischemic stroke is limited by the narrow time window and side effects on brain edema and hemorrhage. This study examined whether tPA, administered by intranasal delivery directly targeting the brain and spinal cord, provides therapeutic benefit during the subacute phase after stroke. Adult male Wistar rats were subjected to permanent right middle cerebral artery occlusion (MCAo). Animals were treated intranasally with saline, 60μg or 600μg recombinant human tPA at 7 and 14. days after MCAo (n = 8/group), respectively. An adhesive-removal test and a foot-fault test were used to monitor functional recovery. Biotinylated dextran amine (BDA) was injected into the left motor cortex to anterogradely label the corticorubral tract (CRT) and the corticospinal tract (CST). Naive rats (n = 6) were employed as normal control. Animals were euthanized 8. weeks after stroke. Compared with saline treated animals, significant functional improvements were evident in rats treated with 600μg tPA (p < 0.05), but not in 60μg tPA treated rats. Furthermore, 600μg tPA treatment significantly enhanced both CRT and CST sprouting originating from the contralesional cortex into the denervated side of the red nucleus and cervical gray matter compared with control group (p < 0.01), respectively. The behavioral outcomes were highly correlated with CRT and CST axonal remodeling. Our data suggest that delayed tPA intranasal treatment provides therapeutic benefits for neurological recovery after stroke by, at least in part, promoting neuronal remodeling in the brain and spinal cord. © 2011 Elsevier Inc.

Renner D.B.,Alzheimers Research Center at Regions Hospital | Frey W.H.,Alzheimers Research Center at Regions Hospital | Hanson L.R.,Alzheimers Research Center at Regions Hospital
Neuroscience Letters | Year: 2012

Adopting RNAi technology for targeted manipulation of gene expression in the central nervous system (CNS) will require delivery of RNAi constructs to the CNS followed by cellular transfection and induction of the RNAi machinery. Significant strides have been made in enhancing RNAi transfection and tailoring knockdown toward specific gene targets, however, delivery of the RNAi constructs to the CNS remains a significant challenge. One possible solution for targeting siRNA to the CNS is intranasal administration, which noninvasively delivers a variety of compounds to the CNS. The current study examined delivery of fluorescently labeled siRNA from the nasal cavity to the olfactory bulbs via the olfactory nerve pathway. siRNA was observed along the length of the olfactory nerve bundles, from the olfactory mucosa of the nasal cavity to the anterior regions of the olfactory bulbs. In the olfactory mucosa, labeled siRNA was found within the olfactory epithelium, Bowman's glands, and associated with blood vessels and bundles of olfactory nerves. In the olfactory bulbs, siRNA was observed in the olfactory nerve, glomerular and mitral cell layers. These results demonstrate a role of the olfactory nerve pathway in targeting siRNA to the olfactory bulbs. Additional investigations will be required to assess the distribution of intranasal siRNA to additional regions of the brain and explore the capacity of the delivered siRNA to silence gene expression in the CNS. © 2012 Elsevier Ireland Ltd.

Renner D.B.,Alzheimers Research Center at Regions Hospital | Svitak A.L.,Alzheimers Research Center at Regions Hospital | Gallus N.J.,Alzheimers Research Center at Regions Hospital | Ericson M.E.,Alzheimers Research Center at Regions Hospital | And 2 more authors.
Journal of Pharmacy and Pharmacology | Year: 2012

Objectives Intranasal delivery has been shown to target peptide therapeutics to the central nervous system (CNS) of animal models and induce specific neurological responses. In an investigation into the pathways by which intranasal administration delivers insulin to the CNS, this study has focused on the direct delivery of insulin from the olfactory mucosa to the olfactory bulbs via the olfactory nerve pathway. Methods Nasal and olfactory tissues of mice were imaged with fluorescent and electron microscopy 30 min following intranasal administration. Key findings Macroscopic analysis confirmed delivery to the anterior regions of the olfactory bulbs. Confocal microscopy captured delivery along the olfactory nerve bundles exiting the nasal mucosa, traversing the cribriform plate and entering the bulbs. With electron microscopy, insulin was found within cells of the olfactory nerve layer and glomerular layer of the olfactory bulbs. Conclusions These results demonstrated that intranasal administration of labelled insulin targeted the CNS through the olfactory nerve pathway in mice. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Schioth H.B.,Uppsala University | Craft S.,University of Washington | Brooks S.J.,Uppsala University | Frey II W.H.,Alzheimers Research Center at Regions Hospital | Benedict C.,Uppsala University
Molecular Neurobiology | Year: 2012

Insulin receptors in the brain are found in high densities in the hippocampus, a region that is fundamentally involved in the acquisition, consolidation, and recollection of new information. Using the intranasal method, which effectively bypasses the blood-brain barrier to deliver and target insulin directly from the nose to the brain, a series of experiments involving healthy humans has shown that increased central nervous system (CNS) insulin action enhances learning and memory processes associated with the hippocampus. Since Alzheimer's disease (AD) is linked to CNS insulin resistance, decreased expression of insulin and insulin receptor genes and attenuated permeation of bloodborne insulin across the blood-brain barrier, impaired brain insulin signaling could partially account for the cognitive deficits associated with this disease. Considering that insulin mitigates hippocampal synapse vulnerability to amyloid beta and inhibits the phosphorylation of tau, pharmacological strategies bolstering brain insulin signaling, such as intranasal insulin, could have significant therapeutic potential to deter AD pathogenesis. © Springer Science+Business Media, LLC 2012.

Benedict C.,Uppsala University | Benedict C.,University of Lübeck | Frey W.H.,Alzheimers Research Center at Regions Hospital | Schioth H.B.,Uppsala University | And 3 more authors.
Experimental Gerontology | Year: 2011

The brain is a major target of circulating insulin. Enhancing central nervous insulin action has been shown to improve memory functions in animals as well as in humans, benefitting in particular hippocampus-dependent (declarative) memory. As Alzheimer's disease (AD) is associated with reduced central nervous insulin signaling and attenuated permeation of blood-borne insulin across the blood-brain-barrier, the cognitive decline in AD patients may at least in part be derived from impaired brain insulin signaling. Thus, therapeutic strategies to overcome central nervous system insulin deficiency and resistance might be an attractive option in the treatment of cognitive impairments like AD. Insulin can be effectively delivered directly to the brain via the intranasal route that enables the hormone to bypass the blood-brain barrier and modulate central nervous functions. This review summarizes a series of studies demonstrating beneficial effects of intranasal insulin on memory functions both in healthy humans and in patients with cognitive impairments such as AD. These experiments in humans consistently indicate that enhancing brain insulin signaling by intranasal administration of the hormone improves hippocampus-dependent memory in the absence of adverse side effects. Considering that insulin also acts as a neuroprotective signal, up-regulating brain insulin levels by intranasal insulin administration appears to be a promising approach in the treatment and prevention of central nervous system insulin deficiency and resistance as found in AD. © 2010 Elsevier Inc.

Wolf D.A.,University of Minnesota | Hanson L.R.,Alzheimers Research Center at Regions Hospital | Aronovich E.L.,University of Minnesota | Nan Z.,University of Minnesota | And 3 more authors.
Molecular Genetics and Metabolism | Year: 2012

Here we provide the first evidence that therapeutic levels of a lysosomal enzyme can bypass the blood-brain barrier following intranasal administration α-l-iduronidase (IDUA) activity was detected throughout the brains of IDUA-deficient mice following a single intranasal treatment with concentrated Aldurazyme® (laronidase) and was also detected after intranasal treatment with an adeno-associated virus (AAV) vector expressing human IDUA. These results suggest that intranasal routes of delivery may be efficacious in the treatment of lysosomal storage disorders. © 2012.

Johnson N.J.,Alzheimers Research Center at Regions Hospital | Hanson L.R.,Alzheimers Research Center at Regions Hospital | Frey W.H.,Alzheimers Research Center at Regions Hospital
Molecular Pharmaceutics | Year: 2010

Intranasal delivery has been shown to noninvasively deliver drugs from the nose to the brain in minutes along the olfactory and trigeminal nerve pathways, bypassing the blood-brain barrier. However, no one has investigated whether nasally applied drugs target orofacial structures, despite high concentrations observed in the trigeminal nerve innervating these tissues. Following intranasal administration of lidocaine to rats, trigeminally innervated structures (teeth, temporomandibular joint (TMJ), and masseter muscle) were found to have up to 20-fold higher tissue concentrations of lidocaine than the brain and blood as measured by ELISA. This concentration difference could allow intranasally administered therapeutics to treat disorders of orofacial structures (i.e., teeth, TMJ, and masseter muscle) without causing unwanted side effects in the brain and the rest of the body. In this study, an intranasally administered infrared dye reached the brain within 10 minutes. Distribution of dye is consistent with dye entering the trigeminal nerve after intranasal administration through three regions with high drug concentrations in the nasal cavity: the middle concha, the maxillary sinus, and the choana. In humans the trigeminal nerve passes through the maxillary sinus to innervate the maxillary teeth. Delivering lidocaine intranasally may provide an effective anesthetic technique for a noninvasive maxillary nerve block. Intranasal delivery could be used to target vaccinations and treat disorders with fewer side effects such as tooth pain, TMJ disorder, trigeminal neuralgia, headache, and brain diseases. © 2010 American Chemical Society.

Toth C.C.,University of Calgary | Jedrzejewski N.M.,University of Calgary | Ellis C.L.,University of Calgary | Frey II W.H.,Alzheimers Research Center at Regions Hospital
Molecular Pain | Year: 2010

Background: Despite the frequency of diabetes mellitus and its relationship to diabetic peripheral neuropathy (DPN) and neuropathic pain (NeP), our understanding of underlying mechanisms leading to chronic pain in diabetes remains poor. Recent evidence has demonstated a prominent role of microglial cells in neuropathic pain states. One potential therapeutic option gaining clinical acceptance is the cannabinoids, for which cannabinoid receptors (CB) are expressed on neurons and microglia. We studied the accumulation and activation of spinal and thalamic microglia in streptozotocin (STZ)-diabetic CD1 mice and the impact of cannabinoid receptor agonism/antagonism during the development of a chronic NeP state. We provided either intranasal or intraperitoneal cannabinoid agonists/antagonists at multiple doses both at the initiation of diabetes as well as after establishment of diabetes and its related NeP state.Results: Tactile allodynia and thermal hypersensitivity were observed over 8 months in diabetic mice without intervention. Microglial density increases were seen in the dorsal spinal cord and in thalamic nuclei and were accompanied by elevation of phosphorylated p38 MAPK, a marker of microglial activation. When initiated coincidentally with diabetes, moderate-high doses of intranasal cannabidiol (cannaboid receptor 2 agonist) and intraperitoneal cannabidiol attenuated the development of an NeP state, even after their discontinuation and without modification of the diabetic state. Cannabidiol was also associated with restriction in elevation of microglial density in the dorsal spinal cord and elevation in phosphorylated p38 MAPK. When initiated in an established DPN NeP state, both CB1 and CB2 agonists demonstrated an antinociceptive effect until their discontinuation. There were no pronociceptive effects demonstated for either CB1 or CB2 antagonists.Conclusions: The prevention of microglial accumulation and activation in the dorsal spinal cord was associated with limited development of a neuropathic pain state. Cannabinoids demonstrated antinociceptive effects in this mouse model of DPN. These results suggest that such interventions may also benefit humans with DPN, and their early introduction may also modify the development of the NeP state. © 2010 Toth et al; licensee BioMed Central Ltd.

Hanson L.R.,Alzheimers Research Center at Regions Hospital
Journal of visualized experiments : JoVE | Year: 2013

Intranasal administration is a method of delivering therapeutic agents to the central nervous system (CNS). It is non-invasive and allows large molecules that do not cross the blood-brain barrier access to the CNS. Drugs are directly targeted to the CNS with intranasal delivery, reducing systemic exposure and thus unwanted systemic side effects. Delivery from the nose to the CNS occurs within minutes along both the olfactory and trigeminal neural pathways via an extracellular route and does not require drug to bind to any receptor or axonal transport. Intranasal delivery is a widely publicized method and is currently being used in human clinical trials. Intranasal delivery of drugs in animal models allows for initial evaluation of pharmacokinetic distribution and efficacy. With mice, it is possible to administer drugs to awake (non-anesthetized) animals on a regular basis using a specialized intranasal grip. Awake delivery is beneficial because it allows for long-term chronic dosing without anesthesia, it takes less time than with anesthesia, and can be learned and done by many people so that teams of technicians can dose large numbers of mice in short periods. Efficacy of therapeutics administered intranasally in this way to mice has been demonstrated in a number of studies including insulin in diabetic mouse models and deferoxamine in Alzheimer's mouse models. The intranasal grip for mice can be learned, but is not easy and requires practice, skill, and a precise grip to effectively deliver drug to the brain and avoid drainage to the lung and stomach. Mice are restrained by hand using a modified scruff in the non-dominant hand with the neck held parallel to the floor, while drug is delivered with a pipettor using the dominant hand. It usually takes 3-4 weeks of acclimating to handling before mice can be held with this grip without a stress response. We have prepared this JoVE video to make this intranasal delivery technique more accessible.

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