Administrative Supplement for Continuity of Biomedical and Behavioral Research Among First-Time Recipients of NIH Research Project Grant Awards - SUMMARY Despite the success of antiretroviral therapeutics (ARTs), they cannot eradicate HIV from reservoirs within the body, particularly those in the central nervous system (CNS). Moreover, opioids upregulate efflux transporters further promoting subtherapeutic concentrations of ART in the CNS. We have used biocompatible ionic liquids (ILs), molten salts comprised of asymmetric cations and anions, that can ‘tune’ the affinity of nanoparticles to different cell types. Using this strategy, we have developed an IL with a balanced affinity for erythrocytes and microglia which promotes nanoparticle ‘hitchhiking’ on erythrocytes to deliver them to the brain, and cells- selective targeting of microglia once delivered to the central compartment. Preliminary data in rats demonstrate ~48% of injected nanoparticles accumulating in the brain within 6 hours, a vast improvement over current nanoparticle delivery strategies. Preliminary analyses indicated that over 90% of CNS nanoparticles were associated with microglia. We have further demonstrated the capacity to load ART (abacavir) into nanoparticles which retained antiviremic efficacy when administered to HIV-infected human peripheral blood mononuclear cells (PBMCs). We hypothesize that we can further improve the tunable profile of our IL formulation to optimize cargo delivery to the brain and target additional cell types (including astrocytes). We anticipate that this cargo delivery strategy will be safe and efficacious in spite of CNS cell adhesion/transporter changes promoted by opioid exposure/dependence. To this end, we will (Aim 1) generate at least 5 novel ILs, in addition to our current lead, with varied cell-type affinity. We will confirm the preference that ILs confer to simian and human blood components as potential cargo carriers. (Aim 2) We will assess the safety (subacute, acute, subchronic, reproductive, mutagenic) and biodistribution of up to 5 novel ILs in rats that are opioid-naïve or opioid-dependent. ILs will be loaded with a premade scramble Cas9 vector with an eGFP reporter to confirm the capacity to deliver CRISPR-Cas9 constructs for potential HIV cure strategies. Safe ILs with a CNS-favorable biodistribution will be loaded with cART (abacavir, dolutegravir, and lamivudine) and assessed for efficacy in SIV-infected or HIV- infected simian or human PBMCs, respectively, or human microglia. All cells will be opioid-naïve or opioid- exposed. ILs with selectivity for microglia and astrocytes will be prioritized. (Aim 3) IL leads (based on CNS distribution and microglial/astrocytic selectivity) will be assessed for in vivo safety, biodistribution, and acute efficacy in a rhesus macaque model of SIV. In macaques, IL-assisted nanoparticles will be loaded with nanogold, in addition to cART, to confirm the time-course of biodistribution via X-ray. SIV infection will be monitored via CSF and blood draws. Complete blood count, chemistry, and cytokine profiling will be conducted on plasma and/or CSF. ART distribution will be confirmed via LC/MS. Gross histopathology will be conducted on organs and CNS tissues will be additionally assessed for microgliosis, astrogliosis, and sublethal neuronal damage. IL- assisted nanoparticles may realize the goal of achieving safe, cell-specific, CNS drug/cargo delivery.
