(370g) Award Submission: Desirable Formulations for Inhalable Particulate Immunotherapeutics Using Model Peg-Based Nanoparticle

The pulmonary microenvironment is the first site of infection for numerous pathogens, and as such, is comprised a host of specialized immune cells that are ripe for immunotherapeutic applications. However, determination of design parameters for inhaled nano-immunotherapies to target these cells has yet to be established. As a model platform, poly(ethylene glycol) diacrylate (PEGDA) nanoparticles (NPs) present highly beneficial characteristics for an inhalable formulation as they offer readily tunable physiochemical properties and have shown non-immunogenic effects in the lung. Herein, we characterize the aerosol and lung trafficking properties of model PEGDA NPs for inhalable immunotherapeutic applications through the modification of surface charge and formulation.

Both cationic and anionic formulations of PEGDA NPs were fabricated with similar hydrodynamic diameters around ~225 nm and low polydispersity indexes, through the addition of 10 wt% charge-establishing co-monomers. In liquid form, both formulations demonstrated robust nebulization through a commercial Aeroneb^® device via non-significant morphological alterations post-nebulization, ascertained through Cryo-Scanning Electron Microscopy (Cryo-SEM) and ImageJ analysis. Dry-powder formulations of PEGDA NPs were also produced via lyophilization with tunable aerodynamic properties when dispersed through a Plastiape RS01 monodose inhaler. To assess phagocytosis capacity of PEGDA NPs using in vitro aerosol delivery, a 3D printed adapter was designed that connected the Aeroneb^® device to air-liquid interface (ALI) transwell cultures of innate immune cells. As expected, cationic NPs demonstrated significant uptake at all dosing conditions based on electrostatic charges; however, NP uptake overall by these cells was greatly reduced at ALI, along with different phenotype responses. To corroborate findings from in vitro studies, murine studies of lung distribution following orotracheal delivery of cationic and anionic PEGDA NPs were performed using two different age groups. Cellular uptake in immune cell subpopulations, NP trafficking, and the cellular inflammatory profile were compared between the two groups for each of the particle formulations, suggesting distinct design rules for the different age groups. Thus, this work outlines an overall approach to formulate particulate-based inhalable therapeutics that can target specific immune cells in the pulmonary microenvironment for a broad range of inhaled immune engineering applications.