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Neurotherapeutics logoLink to Neurotherapeutics
. 2009 Apr;6(2):359–371. doi: 10.1016/j.nurt.2009.02.001

Attenuation of kindled seizures by intranasal delivery of neuropeptide-loaded nanoparticles

Michael J Kubek 1,2,3,, Abraham J Domb 4, Michael C Veronesi 3
PMCID: PMC5084215  PMID: 19332331

Summary

Thyrotropin-releasing hormone (TRH; Protirelin), an endogenous neuropeptide, is known to have anticonvulsant effects in animal seizure models and certain intractable epileptic patients. Its duration of action, however, is limited by rapid tissue metabolism and the blood—brain barrier. Direct nose-to-brain delivery of neuropeptides in sustained-release biodegradable nanoparticles (NPs) is a promising mode of therapy for enhancing CNS neuropeptide bioavailability. To provide proof of principle for this delivery approach, we used the kindling model of temporal lobe epilepsy to show that 1) TRH-loaded copolymer microdisks implanted in a seizure focus can attenuate kindling development in terms of behavioral stage, after-discharge duration (ADD), and clonus duration; 2) intranasal administration of an unprotected TRH analog can acutely suppress fully kindled seizures in a concentration-dependent manner in terms of ADD and seizure stage; and 3) intranasal administration of polylactide nanoparticles (PLA-NPs) containing TRH (TRH-NPs) can impede kindling development in terms of behavioral stage, ADD, and clonus duration. Additionally, we used intranasal delivery of fluorescent dye-loaded PLA-NPs in rats and application of dye-loaded or dye-attached NPs to cortical neurons in culture to demonstrate NP uptake and distribution over time in vivo and in vitro respectively. Also, a nanoparticle immunostaining method was developed as a procedure for directly visualizing the tissue level and distribution of neuropeptide-loaded nanoparticles. Collectively, the data provide proof of concept for intranasal delivery of TRH-NPs as a viable means to 1) suppress seizures and perhaps epileptogenesis and 2) become the lead compound for intranasal anticonvulsant nanoparticle therapeutics.

Key Words: TRH, drug delivery, intranasal, kindling, thyrotropin-releasing hormone, epilepsy therapy

References

  • 1.Kubek MJ, Lorincz MA, Wilber JF. The identification of thyrotropin releasing hormone (TRH) in hypothalamic and extrahypothalamic loci of the human nervous system. Brain Res. 1977;126:196–200. doi: 10.1016/0006-8993(77)90230-X. [DOI] [PubMed] [Google Scholar]
  • 2.Kubek MJ. Thyrotropin-releasing hormone: localization of specific hypothalamic and extrahypothalamic sites of CNS modulation. In: Frederickson RCA, Hendrie H, Hingtgen JN, Aprison MH, editors. Neuroregulation of autonomic, endocrine and, immune systems. Boston: Martinus-Nijhoff; 1986. pp. 265–301. [Google Scholar]
  • 3.Manaker S, Engber TM, Knight PB, Winokur A. Intraventricular 5,7-dihydroxytryptamine increases thyrotropin-releasing hormone content in regions of rat brain. J Neurochem. 1985;45:1315–1318. doi: 10.1111/j.1471-4159.1985.tb05561.x. [DOI] [PubMed] [Google Scholar]
  • 4.Nillni EA, Sevarino KA. The biology of pro-thyrotropin-releasing hormone-derived peptides. Endocr Rev. 1999;20:599–648. doi: 10.1210/er.20.5.599. [DOI] [PubMed] [Google Scholar]
  • 5.Heuer H, Schäfer MK, O’Donnell D, Walker P, Bauer K. Expression of thyrotropin-releasing hormone receptor 2 (TRH-R2) in the central nervous system of rats. J Comp Neurol. 2000;428:319–336. doi: 10.1002/1096-9861(20001211)428:2<319::AID-CNE10>3.0.CO;2-9. [DOI] [PubMed] [Google Scholar]
  • 6.Gary KA, Sevarino KA, Yarbrough GG, Range AJ, Winokur A. The thyrotropin-releasing hormone (TRH) hypothesis of homeostatic regulation: implications for TRH-based therapeutics. J Pharmacol Exp Ther. 2003;305:410–416. doi: 10.1124/jpet.102.044040. [DOI] [PubMed] [Google Scholar]
  • 7.Manaker S, Rainbow TC, Winokur A. Thyrotropin-releasing hormone (TRH) receptors: localization in rat and human central nervous system. In: Boast C, Snowhill E, Altar CA, editors. Quantitative receptor autoradiography. New York: Alan R. Liss; 1986. pp. 103–135. [Google Scholar]
  • 8.Kubek MJ, Sattin A. Effect of electroconvulsive shock on the content of thyrotropin-releasing hormone in rat brain. Life Sci. 1984;34:1149–1152. doi: 10.1016/0024-3205(84)90086-9. [DOI] [PubMed] [Google Scholar]
  • 9.Kubek MJ, Meyerhoff JL, Hill TG, Norton JA, Sattin A. Effects of subconvulsive and repeated electroconvulsive shock on thyrotropin-releasing hormone in rat brain. Life Sci. 1985;36:315–320. doi: 10.1016/0024-3205(85)90116-X. [DOI] [PubMed] [Google Scholar]
  • 10.Rosen JB, Abramowitz J, Post RM. Colocalization of TRH mRNA and Fos-like immunoreactivity in limbic structures following amygdala kindling. Mol Cell Neurosci. 1993;4:335–342. doi: 10.1006/mcne.1993.1043. [DOI] [PubMed] [Google Scholar]
  • 11.Knoblach SM, Kubek MJ. Thyrotropin-releasing hormone release is enhanced in hippocampal slices after electroconvulsive shock. J Neurochem. 1994;62:119–125. doi: 10.1046/j.1471-4159.1994.62010119.x. [DOI] [PubMed] [Google Scholar]
  • 12.Knoblach SM, Kubek MJ. Increases in thyrotropin-releasing hormone messenger RNA expression induced by a model of human temporal lobe epilepsy: effect of partial and complete kindling. Neuroscience. 1997;76:85–95. doi: 10.1016/S0306-4522(96)00361-2. [DOI] [PubMed] [Google Scholar]
  • 13.Gu J, Lynch BA, Anderson D, et al. The antiepileptic drug leve-tiracetam selectively modifies kindling-induced alterations in gene expression in the temporal lobe of rats. Eur J Neurosci. 2004;19:334–345. doi: 10.1111/j.0953-816X.2003.03106.x. [DOI] [PubMed] [Google Scholar]
  • 14.Wilson DN, Chung H, Elliott RC, Bremer E, George D, Koh S. Microarray analysis of postictal transcriptional regulation of neuropeptides. J Mol Neurosci. 2005;25:285–298. doi: 10.1385/JMN:25:3:285. [DOI] [PubMed] [Google Scholar]
  • 15.Kubek MJ, Low WC, Sattin A, Morzorati SL, Meyerhoff JL, Larsen SH. Role of TRH in seizure modulation. Ann N Y Acad Sci. 1989;553:286–303. doi: 10.1111/j.1749-6632.1989.tb46650.x. [DOI] [PubMed] [Google Scholar]
  • 16.Kubek MJ, Liang D, Byrd KE, Domb AJ. Prolonged seizure suppression by a single implantable polymeric-TRH microdisk preparation. Brain Res. 1998;809:189–197. doi: 10.1016/S0006-8993(98)00860-9. [DOI] [PubMed] [Google Scholar]
  • 17.Wan RQ, Noguera EC, Weiss SR. Anticonvulsant effects of intra-hippocampal injection of TRH in amygdala kindled rats. Neuroreport. 1998;9:677–682. doi: 10.1097/00001756-199803090-00021. [DOI] [PubMed] [Google Scholar]
  • 18.Jaworska-Feil L, Kajta M, Budziszewska B, Leskiewicz M, Lasoń W. Protective effects of TRH and its stable analogue, RGH-2202, on kainate-induced seizures and neurotoxicity in rodents. Epilepsy Res. 2001;43:67–73. doi: 10.1016/S0920-1211(00)00178-9. [DOI] [PubMed] [Google Scholar]
  • 19.Veronesi MC, Kubek DJ, Kubek MJ. Intranasal delivery of a thyrotropin-releasing hormone analog attenuates seizures in the amygdala-kindled rat. Epilepsia. 2007;48:2280–2286. doi: 10.1111/j.1528-1167.2007.01218.x. [DOI] [PubMed] [Google Scholar]
  • 20.Rajput SK, Krishnamoorthy S, Pawar C, et al. Antiepileptic potential and behavioral profile of L-pGlu-(2-propyl)-l-His-l-ProNH2, a newer thyrotropin-releasing hormone analog. Epilepsy Behav. 2009;14:48–53. doi: 10.1016/j.yebeh.2008.10.006. [DOI] [PubMed] [Google Scholar]
  • 21.Kubek MJ, Garg BP. Thyrotropin-releasing hormone (TRH) in the treatment of intractable epilepsy. Pediatr Neurol. 2002;26:9–17. doi: 10.1016/S0887-8994(01)00321-6. [DOI] [PubMed] [Google Scholar]
  • 22.Takeuchi Y. Thyrotropin-releasing hormone (protirelin): role in the treatment of epilepsy. CNS Drugs. 1996;6:341–350. doi: 10.2165/00023210-199606050-00001. [DOI] [Google Scholar]
  • 23.Takeuchi Y, Takano T, Abe J, Takikita S, Ohno M. Thyrotropin-releasing hormone: role in the treatment of West syndrome and related epileptic encephalopathies. Brain Dev. 2001;23:662–667. doi: 10.1016/S0387-7604(01)00303-5. [DOI] [PubMed] [Google Scholar]
  • 24.Matsumoto A, Kumagai T, Takeuchi T, Miyazaki S, Watanabe K. Factors influencing effectiveness of thyrotropin-releasing hormone therapy for severe epilepsy in childhood: significance of serum prolactin levels. Epilepsia. 1989;30:45–49. doi: 10.1111/j.1528-1157.1989.tb05279.x. [DOI] [PubMed] [Google Scholar]
  • 25.Nie Y, Schoepp DD, Klaunig JE, Yard M, Lahiri DK, Kubek MJ. Thyrotropin-releasing hormone (protirelin) inhibits potassium-stimulated glutamate and aspartate release from hippocampal slices in vitro. Brain Res. 2005;1054:45–54. doi: 10.1016/j.brainres.2005.06.077. [DOI] [PubMed] [Google Scholar]
  • 26.Veronesi MC, Yard M, Jackson J, Lahiri DK, Kubek MJ. An analog of thyrotropin-releasing hormone (TRH) is neuroprotective against glutamate-induced toxicity in fetal rat hippocampal neurons in vitro. Brain Res. 2007;1128:79–85. doi: 10.1016/j.brainres.2006.10.047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Schomburg L, Turwitt S, Prescher G, Lohmann D, Horsthemke B, Bauer K. Human TRH-degrading ectoenzyme cDNA cloning, functional expression, genomic structure and chromosomal assignment. Eur J Biochem. 1999;265:415–422. doi: 10.1046/j.1432-1327.1999.00753.x. [DOI] [PubMed] [Google Scholar]
  • 28.Heuer H, Schäfer MKH, Bauer K. The thyrotropin-releasing hormone-degrading ectoenzyme: the third element of the thyrotropin-releasing hormone-signaling system. Thyroid. 1998;8:915–920. doi: 10.1089/thy.1998.8.915. [DOI] [PubMed] [Google Scholar]
  • 29.Bom J, Lange T, Kern W, McGregor GP, Bickel U, Fehm HL. Sniffing neuropeptides: a transnasal approach to the human brain. Nat Neurosci. 2002;5:514–516. doi: 10.1038/nn0602-849. [DOI] [PubMed] [Google Scholar]
  • 30.Smolnik R, Molle M, Fehm HL, Bom J. Brain potentials and attention after acute and subchronic intranasal administration of ACTH 4–10 and desacetyl-α-MSH in humans. Neuroendocrinology. 1999;70:63–72. doi: 10.1159/000054460. [DOI] [PubMed] [Google Scholar]
  • 31.Ilium L. Nasal drug delivery: possibilities, problems and solutions. J Control Release. 2003;87:187–198. doi: 10.1016/S0168-3659(02)00363-2. [DOI] [PubMed] [Google Scholar]
  • 32.Kubek MJ, Yard M, Lahiri DK, Domb AJ. Characterization of novel intranasal sustained-release nanoparticles for delivery of neuropeptides to the brain. In: Domb AJ, Tabata Y, Ravi Kumar MNV, Farber S, editors. Nanoparticles for pharmaceutical applications. New York: American Scientific Publishers; 2007. pp. 73–84. [Google Scholar]
  • 33.Shipley MT. Transport of molecules from nose to brain: transneuronal anterograde and retrograde labeling in the rat olfactory system by wheat germ agglutinin—horseradish peroxidase applied to the nasal epithelium. Brain Res Bull. 1985;15:129–142. doi: 10.1016/0361-9230(85)90129-7. [DOI] [PubMed] [Google Scholar]
  • 34.Broadwell RD, Balin BJ, Salcman M. Transcytotic pathway for blood-borne protein through the blood-brain barrier. Proc Natl Acad Sci U S A. 1988;85:632–636. doi: 10.1073/pnas.85.2.632. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.Balin BJ, Broadwell RD. Transcytosis of protein through the mammalian cerebral epithelium and endothelium: I. Choroid plexus and the blood-cerebrospinal fluid barrier. J Neurocytol. 1988;17:809–826. doi: 10.1007/BF01216708. [DOI] [PubMed] [Google Scholar]
  • 36.Morrison EE, Moran DT. Anatomy and ultrastructure of the human olfactory neuroepithelium. In: Doty RL, editor. Handbook of olfaction and gustation. New York: Marcel Dekker; 1995. pp. 75–101. [Google Scholar]
  • 37.Mathison S, Nagilla R, Kompella UB. Nasal route for direct delivery of solutes to the central nervous system: fact or fiction? J Drug Target. 1998;5:415–441. doi: 10.3109/10611869808997870. [DOI] [PubMed] [Google Scholar]
  • 38.Thome RG, Emory CR, Ala TA, Frey WH. Quantitative analysis of the olfactory pathway for drug delivery to the brain. Brain Res. 1995;692:278–282. doi: 10.1016/0006-8993(95)00637-6. [DOI] [PubMed] [Google Scholar]
  • 39.Ilium L. Transport of drugs from the nasal cavity to the central nervous system. Eur J Pharm Sci. 2000;11:1–18. doi: 10.1016/S0928-0987(00)00087-7. [DOI] [PubMed] [Google Scholar]
  • 40.Löscher W. Animal models of epilepsy for the development of antiepileptogenic and disease-modifying drugs: a comparison of the pharmacology of kindling and post-status epilepticus models of temporal lobe epilepsy. Epilepsy Res. 2002;50:105–123. doi: 10.1016/S0920-1211(02)00073-6. [DOI] [PubMed] [Google Scholar]
  • 41.Goddard GV, McIntyre DC, Leech CK. A permanent change in brain function resulting from daily electrical stimulation. Exp Neurol. 1969;25:295–330. doi: 10.1016/0014-4886(69)90128-9. [DOI] [PubMed] [Google Scholar]
  • 42.Racine RJ. Modification of seizure activity by electrical stimulation: I. after-discharge threshold. Electroencephalogr Clin Neurophysiol. 1972;32:269–279. doi: 10.1016/0013-4694(72)90176-9. [DOI] [PubMed] [Google Scholar]
  • 43.Paxinos G, Watson C. The rat brain in stereotaxic coordinates. 2nd ed. New York: Academic Press; 1986. [DOI] [PubMed] [Google Scholar]
  • 44.Brem H, Piantadosi S, Burger PC, the Polymer-Brain Tumor Treatment Group et al. Placebo-controlled trial of safety and efficacy of intraoperative controlled delivery by biodegradable polymers of chemotherapy for recurrent gliomas. Lancet. 1995;345:1008–1012. doi: 10.1016/S0140-6736(95)90755-6. [DOI] [PubMed] [Google Scholar]
  • 45.O’Dowd BF, Lee DK, Huang W, et al. TRH-R2 exhibits similar binding and acute signaling but distinct regulation and anatomic distribution compared with TRH-R1. Mol Endocrinol. 2000;14:183–193. doi: 10.1210/me.14.1.183. [DOI] [PubMed] [Google Scholar]
  • 46.Calzá L, Giardino L, Ceccatelli S, Zanni M, Elde R, Hökfelt T. Distribution of thyrotropin-releasing hormone receptor messenger RNA in the rat brain: an in situ hybridization study. Neuroscience. 1992;51:891–909. doi: 10.1016/0306-4522(92)90528-A. [DOI] [PubMed] [Google Scholar]
  • 47.Przewlocka B, Labuz D, Mika J, et al. Protective effects of TRH and its analogues in chemical and genetic models of seizures. Pol J Pharmacol. 1997;49:373–378. [PubMed] [Google Scholar]
  • 48.Wermeling DP, Miller JL, Rudy AC. Systemic intranasal drug delivery: concepts and applications. Drug Deliv Technol. 2002;2:22–30. [Google Scholar]
  • 49.Wermeling DP, Record KA, Archer SM, Rudy AC. A pharmacokinetic and pharmacodynamic study, in healthy volunteers, of a rapidly absorbed intranasal midazolam formulation. Epilepsy Res. 2009;83:124–132. doi: 10.1016/j.eplepsyres.2008.10.005. [DOI] [PubMed] [Google Scholar]
  • 50.Hanson LR, Frey WH. Intranasal delivery bypasses the blood-brain barrier to target therapeutic agents to the central nervous system and treat neurodegenerative disease. BMC Neurosci. 2008;9(Suppl 3):S5–S5. doi: 10.1186/1471-2202-9-S3-S5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 51.Chen XQ, Fawcett JR, Rahman YE, Ala TA, Frey WH. Delivery of nerve growth factor to the brain via the olfactory pathway. J Alzheimers Disease. 1998;1:35–44. doi: 10.3233/jad-1998-1102. [DOI] [PubMed] [Google Scholar]
  • 52.Frey WH, Liu J, Chen XQ, et al. Delivery of 125I-NGF to the brain via the olfactory route. Drug Delivery. 1997;4:87–92. doi: 10.3109/10717549709051878. [DOI] [Google Scholar]
  • 53.Thome RG, Hanson LR, Ross TM, Tung D, Frey WH. Delivery of interferon-β to the monkey nervous system following intranasal administration. Neuroscience. 2008;152:785–797. doi: 10.1016/j.neuroscience.2008.01.013. [DOI] [PubMed] [Google Scholar]
  • 54.Alcalay RN, Giladi E, Pick CG, Gozes I. Intranasal administration of NAP, a neuroprotective peptide, decreases anxiety-like behavior in aging mice in the elevated plus maze. Neurosci Lett. 2004;361:128–131. doi: 10.1016/j.neulet.2003.12.005. [DOI] [PubMed] [Google Scholar]
  • 55.Matsuoka Y, Gray AJ, Hirata-Fukae C, et al. Intranasal NAP administration reduces accumulation of amyloid peptide and tau hyperphosphorylation in a transgenic mouse model of Alzheimer’s disease at early pathological stage. J Mol Neurosci. 2007;31:165–170. doi: 10.1385/jmn/31:02:165. [DOI] [PubMed] [Google Scholar]
  • 56.Chepurnov SA, Chepurnova NE, Abbasova KR, Goncharov OB. Neuropeptide thyroliberin—an endogenous anticonvulsant in the brain [In Russian] Usp Fiziol Nauk. 2002;33:29–39. [PubMed] [Google Scholar]
  • 57.Schmutz M, Klebs K. Kindling and antiepileptic drugs. In: Bolwig TG, Trimble MR, editors. The clinical relevance of kindling. New York: John Wiley & Sons; 1989. pp. 55–68. [Google Scholar]
  • 58.Domb AJ. Implantable biodegradable polymers for site-specific drug delivery. In: Domb AJ, editor. Polymeric site-specific pharmacotherapy. Chichester, England: John Wiley & Sons; 1994. pp. 1–26. [Google Scholar]
  • 59.Domb A, Maniar M, Bogdansky S, Chasin M. Drug delivery to the brain using polymers. Crit Rev Ther Drag Carrier Syst. 1991;8:1–17. [PubMed] [Google Scholar]
  • 60.Domb AJ, Kubek MJ. Synthesis of Poly(carboxyphenoxypropanesebacic anhydride) for the delivery of drugs to the brain. In: Kobiler D, Lustig S, Shapira S, editors. Blood-brain barrier: drug delivery and brain pathology. New York: Kluwer Academic/Plenum Publishers; 2001. pp. 351–362. [Google Scholar]
  • 61.Hashimoto T, Wada T, Fukuda N, Nagaoka A. Effect of thyrotropin-releasing hormone on pentobarbitone-induced sleep in rats: continuous treatment with a sustained release injectable formulation. J Pharm Pharmacol. 1993;45:94–97. doi: 10.1111/j.2042-7158.1993.tb03690.x. [DOI] [PubMed] [Google Scholar]
  • 62.Ogata A, Nagashima K, Yasui K, Matsuura T, Tashiro K. Sustained release dosage of thyrotropin-releasing hormone improves experimental Japanese encephalitis virus-induced parkinsonism in rats. J Neurol Sci. 1998;159:135–139. doi: 10.1016/S0022-510X(98)00150-6. [DOI] [PubMed] [Google Scholar]
  • 63.Lockman PR, Mumper RJ, Khan MA, Allen DD. Nanoparticle technology for drug delivery across the blood-brain barrier. Drug Dev Ind Pharm. 2002;28:1–13. doi: 10.1081/DDC-120001481. [DOI] [PubMed] [Google Scholar]
  • 64.Gao X, Tao W, Lu W, et al. Lectin-conjugated PEG-PLA nano-particles: preparation and brain delivery after intranasal administration. Biomaterials. 2006;27:3482–3490. doi: 10.1016/j.biomaterials.2006.01.038. [DOI] [PubMed] [Google Scholar]
  • 65.Veronesi MC, Weinert AD, Aldouby Y, Domb AJ, Kubek MJ. Intranasal delivery of thyrotropin-releasing hormone D,L polylactide nanoparticles (TRH-NPs) suppresses kindling development in the rat. Submitted. [DOI] [PubMed]
  • 66.Kubek MJ, Domb AJ, Kubek DJ, Veronesi MC. Thyrotropin-releasing hormone nanoparticles (TRH-NPs): effects on glutamate toxicity, in vitro, and kindled seizures, in vivo. Soc Neurosci Abstr 2008.451.14 (abstract).
  • 67.Bishara A, Domb AJ. PLA stereocomplexes for controlled release of somatostatin analogue. J Control Release. 2005;107:474–483. doi: 10.1016/j.jconrel.2005.05.026. [DOI] [PubMed] [Google Scholar]
  • 68.Veronesi MC, Kubek DJ, Domb AJ, Kubek MJ. Uptake, subregional distribution and time course of intranasally delivered Nile red sustained-release nanoparticles in the rat brain. Soc Neurosci Abstr 2007.166.19 (abstract).
  • 69.Kubek MJ, Hill TG. Methods of thyrotropin-releasing hormone measurement. In: Hingtgen JN, Hellhammer D, Huppmann G, editors. Advanced methods in psychobiology. Toronto: Hogrefe; 1987. pp. 261–279. [Google Scholar]
  • 70.Kissel T, Werner U. Nasal delivery of peptides: an in vitro cell culture model for the investigation of transport and metabolism in human nasal epithelium. J Control Rel. 1998;53:195–203. doi: 10.1016/S0168-3659(97)00253-8. [DOI] [PubMed] [Google Scholar]
  • 71.Vinogradov SV, Bronich TK, Kabanov AV. Nanosized cationic hydrogels for drug delivery: preparation, properties and interactions with cells. Adv Drug Deliv Rev. 2002;54:135–147. doi: 10.1016/S0169-409X(01)00245-9. [DOI] [PubMed] [Google Scholar]
  • 72.Vila A, Sánchez A, Evora C, Soriano I, McCallion O, Alonso MJ. PLA-PEG particles as nasal protein carriers: the influence of the particle size. Int J Pharm. 2005;292:43–52. doi: 10.1016/j.ijpharm.2004.09.002. [DOI] [PubMed] [Google Scholar]
  • 73.Panyam J, Labhasetwar V. Biodegradable nanoparticles for drug and gene delivery to cells and tissue. Adv Drug Deliv Rev. 2003;55:329–347. doi: 10.1016/S0169-409X(02)00228-4. [DOI] [PubMed] [Google Scholar]
  • 74.Gombotz WR, Pettit DK. Biodegradable polymers for protein and peptide drug delivery. Bioconjug Chem. 1995;6:332–351. doi: 10.1021/bc00034a002. [DOI] [PubMed] [Google Scholar]
  • 75.Baker H. Transport phenomena within the olfactory system. In: Doty RL, editor. Handbook of olfaction and gustation. New York: Marcel Dekker; 1995. pp. 173–190. [Google Scholar]
  • 76.Gozes I, Brenneman DE, Geppetti P, et al. Neuropeptides: brain messengers of many faces. Trends Neurosci. 2001;24:687–690. doi: 10.1016/S0166-2236(00)02001-4. [DOI] [PubMed] [Google Scholar]
  • 77.Ilium L. Is nose-to-brain transport of drugs in man a reality? J Pharmacy Pharmacology. 2004;56:3–17. doi: 10.1211/0022357022539. [DOI] [PubMed] [Google Scholar]
  • 78.Agarwal V, Mishra B. Recent trends in drug delivery systems: intranasal drug delivery. Indian J Exp Biol. 1999;37:6–16. [PubMed] [Google Scholar]
  • 79.Kubek MJ, Ringel I, Domb AJ. Issues related to intranasal delivery of neuropeptides to temporal lobe targets. In: Kobiler D, Lustig S, Shapira S, editors. Blood-brain barrier: drug delivery and brain pathology. New York: Kluwer Academic/Plenum Publishers; 2001. pp. 323–350. [Google Scholar]

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