title: Injection of Peptide nanogels preserves postinfarct diastolic function and prolongs efficacy of cell therapy in pigs.
abstract: Accumulating evidence suggests that the benefits of cell therapy for cardiac repair are modest and transient due to progressive harmful cardiac remodeling as well as loss of transplanted cells. We previously demonstrated that injection of peptide nanofibers (NFs) reduces ventricular remodeling and facilitates cell retention at 1 month after acute myocardial infarction (MI) in pigs. However, it remains unclear whether these benefits still persist as the material is being degraded. In this study, 2 mL of placebo or NFs, with or without 1×10(8) mononuclear cells (MNCs), was injected into the pig myocardium after MI (n≥5 in each group), and cardiac function was assessed by echocardiography, including myocardial deformation analyses and catheterization at 3 months post-MI. Our results reveal that MNC-only injection slightly improved cardiac systolic function at 1 month post-MI, but this benefit was lost at later time points (ejection fraction: 42.0±2.3 in MI+normal saline [NS] and 43.5±1.1 in MI+MNCs). In contrast, NF-only injection resulted in improved cardiac diastolic function and reduced pathological remodeling at 3 months post-MI. Furthermore, combined injection of MNCs/NFs provided a greater and longer term cardiac performance (52.1±1.2 in MI+MNCs/NFs, p<0.001 versus MI+NS and MI+MNCs) and 11.3-fold transplanted cell retention. We also found that about 30% NFs remained at 3 months after injection; however, endogenous myofibroblasts were recruited to the NF-injected microenvironment to replace the degraded NFs and preserved cardiac dimensions and mechanics. In conclusion, we demonstrated that injection of NFs contributes to preservation of ventricular mechanical integrity and sustains MNC efficacy at 3 months postinjection.
authors: 1 Institute of Biomedical Sciences , Academia Sinica, Taipei, Taiwan .
authors: Yi-Dong
authors: YD
authors: Lin
authors: Ming-Yao
authors: MY
authors: Chang
authors: Bill
authors: B
authors: Cheng
authors: Yen-Wen
authors: YW
authors: Liu
authors: Lung-Chun
authors: LC
authors: Lin
authors: Jyh-Hong
authors: JH
authors: Chen
authors: Patrick C H
authors: PC
authors: Hsieh
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D016026:Bone Marrow Transplantation; D002196:Capillaries / Q000187:drug effects / Q000473:pathology; D060833:Cellular Microenvironment / Q000187:drug effects; D003971:Diastole / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005355:Fibrosis; D006439:Hemodynamics / Q000187:drug effects; D007267:Injections; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*; D058628:Myofibroblasts / Q000166:cytology / Q000187:drug effects; D057139:Nanofibers / Q000737:chemistry; D000080385:Nanogels; D010455:Peptides / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011094:Polyethyleneimine / Q000494:pharmacology*; D034421:Sus scrofa; D013599:Systole / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D000080385:Nanogels; D010455:Peptides; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D011094:Polyethyleneimine