title: Increased local delivery of antagomir therapeutics to the rodent myocardium using ultrasound and microbubbles.
abstract: Recent developments in microRNA (miRNA) research have identified these as important mediators in the pathophysiological response upon myocardial infarction (MI). Specific miRNAs can inhibit the translation of entire groups of mRNAs, which are involved in specific processes in the pathophysiology after MI, e.g. the fibrotic, apoptotic or angiogenic response. By modulating miRNAs in the heart, these processes can be tuned to improve cardiac function. Antagomirs are effective miRNA-inhibitors, but have a low myocardial specificity and cardiac antagomir treatment therefore requires high doses, which causes side effects. In the present study, ultrasound-triggered microbubble destruction (UTMD) was studied to increase specific delivery of antagomir to the myocardium. Healthy control mice were treated with UTMD and sacrificed at 30min, 24h and 48h, after which antagomir delivery in the heart was analyzed, both qualitatively and quantitatively. Additionally, potential harmful effects of treatment were analyzed by monitoring ECG, analyzing neutrophil invasion and cell death in the heart, and measuring troponin I after treatment. Finally, UTMD was tested for delivery of antagomir in a model of ischemia-reperfusion (I/R) injury. We found that UTMD can significantly increase local antagomir delivery to the non-ischemic heart with modest side-effects like neutrophil invasion without causing apoptosis. Delivered antagomirs enter cardiomyocytes within 30min after treatment and remains there for at least 48h. Interestingly, after I/R injury antagomir already readily enters the infarcted zone and we observed no additional benefit of UTMD for antagomir delivery. This study is the first to explore cardiac antagomir delivery using UTMD. In addition, it is the first to study tissue distribution of short RNA based therapeutics (~22 base pairs) at both the cellular and organ levels after UTMD to the heart in general. In summary, UTMD provides a myocardial delivery strategy for non-vascular permeable cardiac conditions later in the I/R response or chronic conditions like cardiac hypertrophy.
authors.affiliation: Department of Physiology, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands; Institute for Cardiovascular Research-VU (ICaR-VU), VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
authors.forename: Rick F J
authors.initials: RF
authors.lastname: Kwekkeboom
authors.affiliation: Department of Experimental Cardiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Joost P G
authors.initials: JP
authors.lastname: Sluijter
authors.affiliation: Department of Experimental Cardiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: van Middelaar
authors.affiliation: Department of Experimental Cardiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Corina H
authors.initials: CH
authors.lastname: Metz
authors.affiliation: Department of Experimental Cardiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors.forename: Maike A
authors.initials: MA
authors.lastname: Brans
authors.affiliation: Department of Cardiology, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands; Institute for Cardiovascular Research-VU (ICaR-VU), VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
authors.forename: Otto
authors.initials: O
authors.lastname: Kamp
authors.affiliation: Department of Physiology, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands; Department of Experimental Cardiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands; Institute for Cardiovascular Research-VU (ICaR-VU), VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Paulus
authors.affiliation: Department of Physiology, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands; Institute for Cardiovascular Research-VU (ICaR-VU), VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. Electronic address: r.musters@vumc.nl.
authors.forename: René J P
authors.initials: RJ
authors.lastname: Musters
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D008297:Male; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000037:antagonists & inhibitors; D045423:Microbubbles; D009206:Myocardium / Q000378:metabolism*; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D015427:Reperfusion Injury / Q000378:metabolism; D000069453:Ultrasonic Waves
chemical_list: D035683:MicroRNAs; D009841:Oligonucleotides
keywords: Antagomir; Cardiovascular; Drug delivery; Ischemia reperfusion; MicroRNA; Microbubbles; Ultrasound