A multilayer hollow nanocarrier for pulmonary co-drug delivery of methotrexate and doxorubicin in the form of dry powder inhalation formulation

Abstract

Lung cancer is the number one cause of cancer deaths in the global population and remains difficult to treat mainly because of the absence of targeted drug delivery stages and restrictions related with delivery of drugs to deep lung tissues. The aim of the present study was to develop a noninvasive, patient-convenient formulation for the targeted delivery of chemotherapeutics to cancer cells located in the deep lung tissue. A PEGylated paramagnetic hollow-nanosphere was fabricated, fully characterized and used as a nanocarrier for pulmonary co-delivery of Doxorubicin (DOX) and Methotrexate (MTX). In first step, magnetic-silica nanoparticles were synthesized and then coated with amino/acrylate groups and derivatized with polyethylene glycol (PEG). Finally, silica was removed to provide hollow structured nanoparticles. The biocompatibility of blank carriers and the efficiency of MTX-DOX-loaded carriers were also approved by MTT assay and DAPI staining. The aerosolization performance of nanoparticles embedded microspheres were assessed by next generation impactor. The almost natural zeta potential and obvious decrease in silica content observed by EDX and removal of intense silica characteristic peak at FTIR analyses approved the successful removal of silica layer and preparation of hollow-nanospheres. The successful PEGylation of multilayer magnetic hollow-nanospheres catalyzed by boric acid was confirmed by presence of amide groups in FTIR spectra. The developed polymeric nanoparticle showed quite appropriate loading capacity for both DOX and MTX (48%) because of designing adequate negatively and positively charged sites for both drugs. The cytotoxicity assays proved the safety of blank nanoparticles and efficacy of drugs-loaded nanoparticles on lung cancer A549 cell lines. The developed dry powder inhalation formulation of nanoparticles showed appropriate aerosolization performance (fine particle fraction around 22%). It was concluded that these outcomes may open the potentials for efficient pulmonary co-delivery of MTX and DOX to the carcinogenic tissues.

Keywords: Doxorubicin; Dry powder inhalation; Lung cancer; Methotrexate; Pulmonary drug delivery.