Affiliations: [a] Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland | [b] School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland | [c] Trinity Centre for Bioengineering, Trinity College Dublin, College Green, Dublin, Ireland | [d] Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
Correspondence:
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Corresponding author: Garry P. Duffy, Anatomy Department, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland. Tel.: +353 1 4022105; Fax: +353 1 4022355; E-mail: garryduffy@rcsi.ie; http://www.rcsi.ie
Abstract: Background:Cardiovascular diseases (CVD) account for 36% of deaths in Europe and the United States. Gene therapy can act as a therapeutic modality for the treatment of CVD. The use of microRNA mimetics may be advantageous as they regulate important processes in health and pathology. A major hurdle for using miRNA therapies relates to site specific delivery and sufficient cellular uptake of material to achieve efficacy Objective:To assess the feasibility of ultrasound responsive microbubble mediated delivery of miR mimics to cardiomyocytes. Methods:Liposome/microbubble formulations were added to HL-1 cardiomyocytes in the presence/absence of ultrasound (US). Transfection efficacy and functionality was assessed using epifluorescent microscopy, flow cytometry and qRT-PCR. DNA Quantification post-ultrasound mediated transfection of HL-1s using microbubbles was quantified. The capability of miR-133 microbubble formulations to suppress hypertrophy were measured by quantifying changes in cell size. Results:Ultrasound mediated microbubble formulations enhanced intracellular delivery of miR mimics in cardiomyocytes. Both complexed/encapsulated miR-microbubble formulations delivered functional miR mimics and showed no adverse effect on cardiomyocyte viability. Furthermore, ultrasound mediated microbubble transfection of miR-133 mimics reversed cardiomyocyte hypertrophy in an in-vitro model. Conclusions:This novel delivery method has the potential for further development as a targeted delivery strategy for miR therapeutics to the heart.
