Blood brain barrier (BBB) presents a significant challenge to the delivery of therapeutic agents to the brain. Tight junctions prevent free diffusion of small polar molecules across this barrier. However, entry of large lipid soluble molecules is also limited across BBB by the presence of several ABC (ATP binding cassette) efflux transporters i.e., P- glycoprotein (P-gp) and multi-drug resistance associated proteins (MRPs). Inclusion of HIV protease inhibitors (PIs) in `highly active antiretroviral therapy'(HAART) has substantially improved clinical outcomes in AIDS patients. However, a major challenge with current anti-HIV drug regimen is the inability of PIs to attain sufficient concentrations in CNS resulting in persistent viral replication and a HIV sanctuary site in the brain parenchyma. Sub-therapeutic concentration of PIs in CNS also leads to drug resistance and AIDS related dementia. One of the major factors that limit CNS permeation of PIs is the presence of efflux proteins i.e, P-gp and MRPs on brain capillary endothelial cells. Therefore the objective of this application is to develop novel prodrug strategies to circumvent ABC transporter mediated efflux and to improve brain permeation of HIV protease inhibitors. Prodrug modification of PIs is one such promising strategy where the ligand linked PIs can bypass efflux processes by becoming substrates for influx transporters such as vitamin, and amino acid transporters present on the blood brain barrier. We hypothesize that the ligand coupled PIs will permeate CNS efficiently by binding and translocating by membrane influx transporters/receptors and bypass membrane efflux pumps like P-gp and MRP. Our preliminary results clearly indicate that prodrugs designed for influx transporters can efficiently bypass efflux pumps. We also propose a novel pro-prodrug strategy where a dipeptide prodrug moiety will be designed so that it can be identified by the peptide transporter present on the intestinal epithelium. Once the dipeptide prodrug reaches systemic circulation it will be converted to amino acid prodrug which can then be identified by the amino acid transporters on the BBB. This pro-prodrug strategy will not only result in increased oral absorption of poorly absorbed PIs but also can result in higher CNS concentrations. Rat brain endothelial cells co-cultured with astrocytes will be employed as a model mimicking BBB to study permeation of the synthesized prodrugs. Finally, in-vivo rat brain microdialysis will be employed to delineate CNS pharmacokinetics of prodrugs following oral and IV administrations. Thus, overall hypothesis of this grant application is to design prodrug and pro-prodrug derivatives of PIs that may result in (a) circumvention of P-gp and MRP mediated efflux (b) higher permeability due to enhanced uptake by influx transporters, (c) higher oral bioavailability (d) lower plasma protein binding (e) higher metabolic stability against CYP 450 enzymes (f) higher aqueous solubility and (g) higher brain uptake.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Special Emphasis Panel (ZRG1-BDCN-A (11))
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Zhang, Hao
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University of Missouri Kansas City
Schools of Pharmacy
Kansas City
United States
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Mandal, Abhirup; Pal, Dhananjay; Mitra, Ashim K (2016) Circumvention of P-gp and MRP2 mediated efflux of lopinavir by a histidine based dipeptide prodrug. Int J Pharm 512:49-60
Mitra, Ashim K; Agrahari, Vibhuti; Mandal, Abhirup et al. (2015) Novel delivery approaches for cancer therapeutics. J Control Release 219:248-268
Khurana, Varun; Minocha, Mukul; Pal, Dhananjay et al. (2014) Inhibition of OATP-1B1 and OATP-1B3 by tyrosine kinase inhibitors. Drug Metabol Drug Interact 29:249-59
Vadlapatla, Ramya Krishna; Patel, Mitesh; Paturi, Durga K et al. (2014) Clinically relevant drug-drug interactions between antiretrovirals and antifungals. Expert Opin Drug Metab Toxicol 10:561-80
Kwatra, Deep; Vadlapudi, Aswani Dutt; Vadlapatla, Ramya Krishna et al. (2014) Binary and ternary combinations of anti-HIV protease inhibitors: effect on gene expression and functional activity of CYP3A4 and efflux transporters. Drug Metabol Drug Interact 29:101-10
Khurana, Varun; Kwatra, Deep; Pal, Dhananjay et al. (2014) Molecular expression and functional activity of vitamin C specific transport system (SVCT2) in human breast cancer cells. Int J Pharm 474:14-24
Patel, Mitesh; Sheng, Ye; Mandava, Nanda K et al. (2014) Dipeptide prodrug approach to evade efflux pumps and CYP3A4 metabolism of lopinavir. Int J Pharm 476:99-107
Khurana, Varun; Minocha, Mukul; Pal, Dhananjay et al. (2014) Role of OATP-1B1 and/or OATP-1B3 in hepatic disposition of tyrosine kinase inhibitors. Drug Metabol Drug Interact 29:179-90
Wang, Zhiying; Pal, Dhananjay; Patel, Ashaben et al. (2013) Influence of overexpression of efflux proteins on the function and gene expression of endogenous peptide transporters in MDR-transfected MDCKII cell lines. Int J Pharm 441:40-9
Renukuntla, Jwala; Vadlapudi, Aswani Dutt; Patel, Ashaben et al. (2013) Approaches for enhancing oral bioavailability of peptides and proteins. Int J Pharm 447:75-93

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