Specific targeting and noninvasive magnetic resonance imaging of an asthma biomarker in the lung using polyethylene glycol functionalized magnetic nanocarriers

Abstract

Simultaneous inhibition of IL4 and IL13 via the common receptor chain IL4Rα to block adequately their biologic effects presents a promising therapeutic approach to give the additional relief required for asthma patients. In this study, superparamagnetic iron oxide nanoparticles were conjugated with anti-IL4Rα blocking antibodies via polyethylene glycol (PEG) polymers. The delivery of these blocking antibodies to the inflammatory sites in the lung via the developed nanocarriers was assessed using noninvasive free-breathing pulmonary MRI. Biocompatibility assays confirmed the safety of the developed nanocarriers for pre-clinical investigations. For all the investigated formulations, nanocarriers were found to be very stable at neutral pH. However, the stability noticeably decreased with the PEG length in acidic environment and thus the loaded antibodies were preferentially released. Immunofluorescence and fluorimetry assays confirmed the binding of the nanocarriers to the IL4Rα asthma biomarker. Pulmonary MRI performed using an ultra-short echo time sequence allowed simultaneous noninvasive monitoring of inflammatory responses induced by ovalbumin challenge and tracking of the developed nanocarriers, which were found to colocalize with the inflammatory sites in the lung. Targeting of the developed nanocarriers to areas rich in IL4Rα positive inflammatory cells was confirmed using histological and flow cytometry analyses. The anti-IL4Rα-conjugated nanocarriers developed here have been confirmed to be efficient in targeting key inflammatory cells during chronic lung inflammation following intrapulmonary administration. Targeting efficiency was monitored using noninvasive MRI, allowing detection of the nanocarriers' colocalizations with the inflammatory sites in the lung of ovalbumin-challenged asthmatic mice. Copyright © 2015 John Wiley & Sons, Ltd.

Blocking Interleukin-4 Receptor α Using Polyethylene Glycol Functionalized Superparamagnetic Iron Oxide Nanocarriers to Inhibit Breast Cancer Cell Proliferation

“…Quantification by bicinchoninic acid protein assay revealed that the amount of conjugated IL4Rα antibodies was approximately 13.7 μg per milligram of SPION. Further details regarding characterization of these nanoparticles have been published elsewhere [13]. …”

“…The nanocarriers developed here have been previously validated to be highly safe and revealed excellent stability at neutral pH, while their stability decreased remarkably in acidic environments with the use of 2,000 g/mol PEG chain linker; thus, they can preferentially release conjugated blocking antibodies [13]. …”

“…SPIONs were conjugated to polyethylene glycol (PEG) polymer with a molecular weight of 2,000 g/mol as previously described [12]. Thiolated IL4Rα monoclonal antibodies (BD Biosciences, San Diego, CA), which specifically binds to CD124 (also known as the α subunit of mouse IL4Rα), were conjugated to maleimide-functionalized SPIONs as previously described [13]. The anti–SPION-IL4Rα were purified on magnetic-activated cell sorting columns (Miltenyi Biotec, Bergisch Gladbach, Germany).…”

“…The hydrodynamic size and zeta potential (i.e., surface charge) of nanoparticles before and after their conjugation with IL4Rα antibodies were measured using Zetasizer Nano ZS90 (Malvern Instruments, Malvern, UK). The amount of IL4Rα antibodies conjugated to SPION was quantified as described elsewhere [13]. …”

“…These cancer cells were chosen since their tumor growth in vivo and metastatic spread in mice closely mimics stage IV human breast cancer [14]. SPION-IL4Rα and DOX were applied at a concentration of 5 μg/mL each based on our previous studies [13,15]. …”