Anti-angiogenic nanotherapy inhibits airway remodeling and hyper-responsiveness of dust mite triggered asthma in the Brown Norway rat

Although angiogenesis is a hallmark feature of asthmatic inflammatory responses, therapeutic anti-angiogenesis interventions have received little attention. Objective: Assess the effectiveness of anti-angiogenic Sn2 lipase-labile prodrugs delivered via α(v)β(3)-micellar nanotherapy to suppress microvascular expansion, bronchial remodeling, and airway hyper-responsiveness in Brown Norway rats exposed to serial house dust mite (HDM) inhalation challenges. Results: Anti-neovascular effectiveness of α(v)β(3)-mixed micelles incorporating docetaxel-prodrug (Dxtl-PD) or fumagillin-prodrug (Fum-PD) were shown to robustly suppress neovascular expansion (p<0.01) in the upper airways/bronchi of HDM rats using simultaneous (19)F/(1)H MR neovascular imaging, which was corroborated by adjunctive fluorescent microscopy. Micelles without a drug payload (α(v)β(3)-No-Drug) served as a carrier-only control. Morphometric measurements of HDM rat airway size (perimeter) and vessel number at 21d revealed classic vascular expansion in control rats but less vascularity (p<0.001) after the anti-angiogenic nanotherapies. CD31 RNA expression independently corroborated the decrease in airway microvasculature. Methacholine (MCh) induced respiratory system resistance (Rrs) was high in the HDM rats receiving α(v)β(3)-No-Drug micelles while α(v)β(3)-Dxtl-PD or α(v)β(3)-Fum-PD micelles markedly and equivalently attenuated airway hyper-responsiveness and improved airway compliance. Total inflammatory BAL cells among HDM challenged rats did not differ with treatment, but α(v)β(3)(+ )macrophages/monocytes were significantly reduced by both nanotherapies (p<0.001), most notably by the α(v)β(3)-Dxtl-PD micelles. Additionally, α(v)β(3)-Dxtl-PD decreased BAL eosinophil and α(v)β(3)(+ )CD45(+) leukocytes relative to α(v)β(3)-No-Drug micelles, whereas α(v)β(3)-Fum-PD micelles did not. Conclusion: These results demonstrate the potential of targeted anti-angiogenesis nanotherapy to ameliorate the inflammatory hallmarks of asthma in a clinically relevant rodent model

Cellular Export Fate of Liposomal Spherical Nucleic Acids

Liposomal spherical nucleic acids (LSNAs) are useful structures for oligonucleotide-based cell modulation because of their biocompatibility and ability to readily enter cells without transfection agents. Understanding LSNA trafficking is key to developing applications, but while much is understood about LSNA cell uptake, little is known about their export fate. Here, we study LSNA export through pulse-chase studies with fluorophore-labeled LSNAs. Our findings show that the components of LSNAs are differentially exported by cells, with the phospholipids showing 90–100% export and the oligonucleotides showing 30–45% export over 24 h in RAW264.7 macrophages. Despite the increase in the level of uptake of LSNAs, these percentages are not significantly influenced by whether the materials are taken up as LSNAs or as the individual components. The exported oligonucleotide material consists of a full-length oligonucleotide with the phospholipid anchor modified by loss of a fatty acid. The exported liposome-derived phospholipids also had a fatty acid removed. Moreover, the exported oligonucleotide-lysophospholipid conjugates retain immunostimulatory potential. These findings indicate that after cellular entry LSNAs are degraded into lysophospholipids, something to which they are susceptible due to the presence of hydrolyzable ester bonds. The export percentage of the resultant materials over 24 h is independent of the amount imported, such that greater initial import leads to a similar fold increase in exported material. This work therefore reveals an intracellular feature of LSNAs and shows that the enhanced uptake achieved with LSNAs can be exploited to maximize the amount of material subsequently exported, suggesting avenues for leveraging pharmacologic effects from exported LSNA components