Bioluminescent imaging of reporter gene expression in the lungs of wildtype and model mice following the administration of PEG‐stabilized DNA nanoparticles

Abstract

DNA nanoparticles (DNPs) formed by compacting DNA with polyethyleneglycolylated poly-L-lysine are a nonviral vector shown to be safe and efficacious in animals and humans. To extend our capabilities of assessing the efficacy and duration of expression achieved by DNPs, we tested the utility of bioluminescent imaging (BLI) of transgene expression in wildtype and cystic fibrosis (CF) mouse models. We tested the effect of route of administration, mouse coat color, anesthesia, dose, and promoter sequence on the level and duration of expression. Furthermore, we investigated the correlation between imaging and direct analysis of luciferase expression in lung homogenates. We found that intratracheal instillation, and the use of deep and prolonged anesthesia with avertin produced significantly higher expression compared with intranasal administration, and the use of lighter anesthesia with isoflurane. Although similar expression was observed for both dark and light coat animals, imaging signal intensity was attenuated in mice with dark fur. Furthermore, good correlation between imaging and direct homogenate analysis was observed for single dose (r = 0.96), and dose response studies in wildtype (r = 0.82) and CF mice (r = 0.87). Finally, we used imaging to track gene expression over a 56-day time course. We found that the human ubiquitin B promoter gives stable transgene expression up to 49 days following nanoparticle administration, while expression with the cytomegalovirus promoter diminished after 2 days and returned to background levels by day 14. Taken together, our results demonstrate that BLI is an effective and useful modality for measuring gene expression conferred by DNPs in the lung.

DNA nanoparticle-mediated thymulin gene therapy prevents airway remodeling in experimental allergic asthma

“…1A), in agreement with previous reports for CK 30 PEG-DNA nanoparticles [19, 27]. DNA nanoparticles exhibited a near neutral surface charge (−1.5 ± 3.9 mV), indicating the presence of PEG coating on the particle surface, and hydrodynamic diameter determined by dynamic light scattering was 89.0 ± 0.4 nm (PDI ~0.10).…”

Enhancement of airway gene transfer by DNA nanoparticles using a pH-responsive block copolymer of polyethylene glycol and poly-l-lysine

“…In the present study, the human beta-actin promoter resulted in sustained luciferase activity that increased over time (up to two weeks) in mice treated with PEG-CH 12 K 18 DNA nanoparticles or PEG-CK 30 DNA nanoparticles by oropharyngeal aspiration. The sustained luciferase activity mediated by DNA nanoparticles is consistent with a recent report by Ziady et al in which PEG-CK 30 DNA nanoparticles containing a luciferase plasmid driven by the ubiquitin B promoter resulted in sustained pulmonary expression in C57BL/6 mice that peaked within the first 14 days [46]. The authors also reported negligible luciferase activity in mice that received naked DNA, suggesting that compaction was necessary for efficient uptake and expression of DNA.…”

“…Such transient expression profiles are not ideal for the treatment of chronic lung disease, which requires sustained transgene expression at therapeutic levels. Alternatively, a number of eukaryotic promoters are capable of sustained pulmonary transgene expression, including the ubiquitin C [45, 47] and ubiquitin B [46, 48] promoters. In the present study, the human beta-actin promoter resulted in sustained luciferase activity that increased over time (up to two weeks) in mice treated with PEG-CH 12 K 18 DNA nanoparticles or PEG-CK 30 DNA nanoparticles by oropharyngeal aspiration.…”

Nanomaterials for Management of Lung Disorders and Drug Delivery

“…NPs have longer lung retention time compare to that of microparticles [92]. Ziady et al [93] also developed a DNA/polymer complex for bioluminescent imaging (BLI) of gene expression in the lung of wild type and cystic fibrosis mouse models. They found that BLI was an efficient imaging tool for the evaluation of gene expression mediated by these NPs and could be useful for clinical imaging applications in the future [93].…”