PET imaging of a collagen matrix reveals its effective injection and targeted retention in a mouse model of myocardial infarction. (May 2015)

• Record Type: Journal Article
• Authors: Ahmadi, Ali; L. Thorn, Stephanie; Alarcon, Emilio I.; Kordos, Myra; Padavan, Donna T.; Hadizad, Tayebeh; Cron, Greg O.; Beanlands, Rob S.; DaSilva, Jean N.; Ruel, Marc; deKemp, Robert A.; Suuronen, Erik J.
• Is Part Of: Biomaterials. Volume 49(2015)
• Page Start: 18
• Page End: 26
• Publication Date: 2015-05
• Subjects: Biomaterials -- Collagen matrix -- Fluorescence imaging -- Injectable -- PET imaging; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2015.01.016
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: Injectable biomaterials have shown promise for cardiac regeneration therapy. However, little is known regarding their retention and distribution upon application in vivo . Matrix imaging would be useful for evaluating these important properties. Herein, hexadecyl-4-[ 18 F]fluorobenzoate ( 18 F-HFB) and Qdot labeling was used to evaluate collagen matrix delivery in a mouse model of myocardial infarction (MI). At 1wk post-MI, mice received myocardial injections of 18 F-HFB- or Qdot-labeled matrix to assess its early retention and distribution (at 10 min and 2 h) by positron emission tomography (PET), or fluorescence imaging, respectively. PET imaging showed that the bolus of matrix at 10 min redistributed evenly within the ischemic territory by 2 h. Ex vivo biodistribution revealed myocardial matrix retention of ∼65%, which correlated with PET results, but may be an underestimate since 18 F-HFB matrix labeling efficiency was ∼82%. For covalently linked Qdots, labeling efficiency was ∼96%. Ex vivo Qdot quantification showed that ∼84% of the injected matrix was retained in the myocardium. Serial non-invasive PET imaging and validation by fluorescence imaging confirmed the effectiveness of the collagen matrix to be retained and redistributed within the infarcted myocardium. This study identifies matrix-targeted imaging as a promising modality for assessing the biodistribution of injectable biomaterials for application in the heart.