DUAL-DRUG NANOPARTICLE FORMULATION FOR INHALED DELIVERY IN IDIOPATHIC PULMONARY FIBROSIS TREATMENT

Abstract

Idiopathic Pulmonary Fibrosis (IPF) is a chronic lung disease which causes scarring of the lung tissue and makes breathing more difficult [1]. Pirfenidone (PFD), one of only two FDA-approved therapies for IPF, is clinically shown to reduce the rate of scarring of lung tissue; however, it is limited by the need for daily oral administration of chronic doses which can lead to off-target side effects [2]. Inhalable nanoparticle-based (NP) drug delivery systems allow for targeted, controlled drug release in the deep lung tissue while increasing contact with and uptake by lung cells [3]. Research has found that Galectin-3 plays an important role in the pathogenesis of human IPF [4]. The goal of this project is to develop, characterize, and evaluate a dual-drug nanoparticle formulation that can be simultaneously used for targeted Galectin-3 inhibition and sustained PFD release, to provide an effective combination therapy to treat IPF. The drug-loaded polymeric NPs were prepared using a standard double emulsion technique followed by ultracentrifugation to purify the particles and lyophilization for long term storage. Surface decoration with citrus pectin (CP) was carried out on the freeze-dried (lyophilized) particles to yield citrus pectin coated NPs (CP-NPs). Particle size, size distribution, and zeta potential (ZP) were measured using a dynamic light scattering (DLS) instrument. A UV-Vis spectrophotometric method was developed to determine the encapsulation efficiency of the PFD-loaded NPs as well as quantify amount of CP coated on final CP-NPs formulation. Fourier transform infrared spectroscopy (FTIR) was carried out to confirm the surface coating of the CP-NPs. For stability studies, CP-NPs were incubated at 37 degrees Celsius for 7 days in both phosphate-buffered saline (PBS) and simulated lung fluid (SLF), with particle sizes of the NPs measured daily. Cytocompatibility of the CP-NPs was determined by treating MRC5, an immortalized human fetal lung fibroblast cell line, with CP-NPs at varying concentrations. The following NP characterization data suggests that a uniform and high-concentration NP batch was formulated: Particle size of 190.1 d.nm with 100% peak intensity, ZP of -8.21, PFD encapsulation efficiency of 71.95%, and CP conjugation efficiency of 40.3%. The FTIR spectra captured for CP-NPs displayed bands indicative of O-H bond stretching of carboxyl groups, confirming presence of CP. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images confirmed uniform size and spherical morphology of both coated and un-coated NPs. TEM images displayed core-shell structure of CP-NPs. Stability studies showed NP diameter to have minimal