Noncovalent PEG Coating of Nanoparticle Drug Carriers Improves the Local Pharmacokinetics of Rectal Anti-HIV Microbicides

Antiretroviral drug nanocarriers hold great promise for developing anti-human immunodeficiency virus (HIV) rectal microbicides. However, challenges remain, namely, concerning which properties are more suited for enhancing colorectal distribution and retention of microbicide compounds. In this work, we developed and assessed the in vitro and in vivo performance of poly(lactic- co-glycolic acid) (PLGA)-based nanoparticles (NPs) as carriers for the model drug efavirenz (EFV). We particularly focused on the effect of noncovalent poly(ethylene glycol) coating of PLGA NPs (PEG-PLGA NPs) conferring a mucus-diffusive behavior on the pharmacokinetics (PK) of EFV following rectal administration to mice. Drug-loaded PLGA NPs and PEG-PLGA NPs (200-225 nm) were obtained by nanoprecipitation. Both types of systems were able to retain native antiretroviral activity of EFV in vitro, while featuring lower cytotoxicity against different epithelial cell lines and HIV target cells. Also, PLGA NPs and PEG-PLGA NPs were readily taken up by colorectal cell lines and mildly reduced EFV permeation while increasing membrane retention in Caco-2 and Caco-2/HT29-MTX cell monolayer models. When administered intrarectally to CD-1 mice in phosphate-buffered saline (pH 7.4), EFV-loaded PEG-PLGA NPs consistently provided higher drug levels in colorectal tissues and lavages, as compared to free EFV or drug-loaded PLGA NPs. Mean values for the area-under-the-curve between 15 min and 12 h following administration were particularly higher for PEG-PLGA NPs in distal and middle colorectal tissues, with relative bioavailability values of 3.7 and 29, respectively, as compared to free EFV (2.2 and 6.0 over PLGA NPs, respectively). Systemic exposure to EFV was reduced for all treatments. NPs were further shown safe after once-daily administration for 14 days, as assessed by histological analysis of colorectal tissues and chemokine/cytokine assay of rectal lavages. Overall, PEG-PLGA NPs demonstrated to be safe carriers for rectal microbicide drug delivery and able to provide enhanced local PK that could be valuable in preventing rectal HIV transmission.

Mucus and Cell-Penetrating Nanoparticles Embedded in Nano-into-Micro Formulations for Pulmonary Delivery of Ivacaftor in Patients with Cystic Fibrosis

Here, mucus-penetrating nanoparticles (NPs) for pulmonary administration of ivacaftor in patients with cystic fibrosis (CF) were produced with the dual aim of enhancing ivacaftor delivery to the airway epithelial cells, by rapid diffusion through the mucus barrier, and at the same time, promoting ivacaftor lung cellular uptake. Pegylated and Tat-decorated fluorescent nanoparticles (FNPs) were produced by nanoprecipitation, starting from two synthetic copolymers, and showed nanometric sizes (∼70 nm), a slightly negative ζ potential, and high cytocompatibility toward human bronchial epithelium cells. After having showed the significant presence of poly(ethylene glycol) chains and Tat protein onto the FNP surface, the FNP mucus-penetrating ability, ivacaftor release profile, and lung cellular uptake were studied in the presence of CF-artificial mucus as a function of the FNP surface chemical composition. Moreover, microparticle-based pulmonary drug-delivery systems composed of mucus-penetrating FNPs loaded with ivacaftor and mannitol were prepared by using the nano-into-micro strategy and realized by spray-drying, thereby providing optimal preservation and stabilization of FNP technological and fluorescence properties.