We have fabricated a clinically relevant size of hCMP with trilineage cardiac cells derived from human induced-pluripotent stem cells. The hCMP matures in vitro during 7 days of dynamic culture. Transplantation of this type of hCMP results in significantly reduced infarct size and improvements in cardiac function that are associated with reduction in left ventricular wall stress. The hCMP treatment is not associated with significant changes in arrhythmogenicity.

Vascular endothelial growth factor (VEGF) is a well-characterized proangiogenic cytokine that has been shown to promote neovascularization in hearts of patients with ischemic heart disease but can also lead to adverse effects depending on the dose and mode of delivery. We investigated whether prolonged exposure to a low dose of VEGF could be achieved by encapsulating VEGF in polylactic coglycolic acid nanoparticles and whether treatment with VEGF-containing nanoparticles improved cardiac function and protected against left ventricular remodeling in the hearts of mice with experimentally induced myocardial infarction. Polylactic coglycolic acid nanoparticles with a mean diameter of ~113 nm were generated via double emulsion and loaded with VEGF; the encapsulation efficiency was 53.5 ± 1.7% (107.1 ± 3.3 ng VEGF/mg nanoparticles). In culture, VEGF nanoparticles released VEGF continuously for at least 31 days, and in a murine myocardial infarction model, VEGF nanoparticle administration was associated with significantly greater vascular density in the peri-infarct region, reductions in infarct size, and improvements in left ventricular contractile function 4 wk after treatment. Thus, our study provides proof of principle that nanoparticle-mediated delivery increases the angiogenic and therapeutic potency of VEGF for the treatment of ischemic heart disease. NEW & NOTEWORTHY Vascular endothelial growth factor (VEGF) is a well-characterized proangiogenic cytokine but has a short half-life and a rapid clearance rate. When encapsulated in nanoparticles, VEGF was released for 31 days and improved left ventricular function in infarcted mouse hearts. These observations indicate that our new platform increases the therapeutic potency of VEGF.

Preconditioning with the ROCK inhibitor Y-27632 increased the engraftment of transplanted hiPSC-CM in a murine MI model, while reversibly impairing hiPSC-CM contractility and promoting adhesion.

NPs encapsulated with CHIR + FGF1 exerted substantial myocardial protective effects and represents a potentially novel strategy for improving postischemic myocardial protection. Results Identification of chemicals that promote cell cycle activity of human induced pluripotent stem cell-derived cardiomyocytes. Using the BrdU incorporation assay, we screened several chemicals for their capacity to enhance the cell cycle activity of cultured human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We picked hiPSC-CMs because they are easy to handle and represent a practical system for drug testing and screening (5). These chemicals included Ly294002 (PI3K inhibitor) (6), FGF1 (6, 7), SB203580 and VX702 (p38 MAPK inhibitors) (6), KN93 (Ca 2+ /calmodulin-dependent protein kinase II inhibitor) (8), Su1498 (Flk-1 inhibitor) (8), and CHIR99021 (Wnt activator and GSK3α and 3β inhibitor) (8, 9). We found a combination of 5 μM CHIR99021 and 100 ng/mL FGF1 was the most potent treatment to induce cell cycle in hiPSC-derived cardiomyocytes (Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.132796DS1). Characterization of CHIR-FGF1-NPs. We have previously shown that PLGA NPs can be used as a platform for slow release (up to 4 weeks) of chemicals to injured animal hearts and that they provide cardioprotection (2). To characterize the long-term cardioprotective function of the FGF/CHIR combination in vivo, we formulated the PLGA NPs with these 2 factors. The size of PLGA NPs was measured using scanning electron microscopy, for both CHIR99021-and FGF1-loaded NPs (Supplemental Figure 2, A and B). Quantification of particle diameter for CHIR-NPs (Supplemental Figure 2C) and FGF1-NPs (Supplemental Figure 2D) yielded values of 123.63 ± 44.48 nm and 129.57 ± 45.94 nm, respectively. The size and shape of CHIR-NPs and FGF1-NPs were uniform. The encapsulation efficiency of CHIR-NPs and FGF1-NPs, i.e., (the amount encapsulated/total amount available) × 100%, was 50.41% and 62.8 ± 1.6%, respectively. The concentration of encapsulated CHIR and FGF1 was 8.07 μg/mg and 1.26 ± 0.03 μg/mg, respectively. Determination of release kinetics of CHIR-and FGF1-loaded NPs as a function of time, using either NanoDrop via UV-Vis spectrophotometer (for CHIR) or ELISA (for FGF1), and the cumulative percentage of CHIR and FGF1 released from NPs, are shown in Supplemental Figure 2, E and F. When 1000 μg of CHIR-and FGF1-loaded NPs were incubated in 1000 μL of Dulbecco's phosphate-buffered saline (DPBS), pH 7.4 at 37°C, 55% of the encapsulated CHIR was released during the first day and 85% by day 15 (Supplemental Figure 2E). In contrast, 55% of the encapsulated FGF1 was released during the initial 3 days, and 63% was released by day 10. Notably, between day 1 and day 30, the release kinetics strictly followed the Korsmeyer-Peppas model for FGF1-NPs (Supplemental Figure 2F). Fitting this model, C t /C 0 = kt n , where C t = concentration at time t; C 0 = equilibrium concentration; ...

Introduction: We aimed at to investigate whether activation of both FGF1 and Wnt1 synergistically enhances angiogenesis and render the cardioprotection in hearts with post infarction LV remodeling. Materials and methods: CHIR99021 (a Wnt1 activator) and FGF1 were encapsulated into poly lactic-co-glycolic acid nanoparticles (CHIR99021/FGF1-NPs). Ischemic heart models were generated in C57BL/6 mice or Yorkshire swine by ligation of the left anterior descending coronary. The mice were randomly divided into 6 groups: Myocardial infarction (MI) Only (n=11), MI with nanoparticles (CHIR99021 or/and FGF1 loaded) injection (n=12, each), MI with non-loaded nanoparticles injection (n=11) and Sham group (n=10). The swine were divided into 3 groups: ischemic reperfusion injury (IRI) (n=4), IRI with CHIR99021/FGF-NPs injection (n=4) and Sham group (n=4). Left ventricle function 4 week after surgery were evaluated by Echocardiography. Cell proliferation was assessed via immunostaining in ischemic hearts and in cultivated human umbilical vein endothelial cells (HUVECs) and Human vascular smooth muscle cells (HVSMCs) using the following markers: Ki67, Brdu, PH3, and Aurora B. Apoptosis was determined with TUNEL staining. Cardiac fibrosis was evaluated via Sirius red and Fast green staining (mice) and magnetic resonance imaging (swine). Results: CHIR99021/FGF1-NPs treatment attenuated fibrosis and preserved heart contractile function in mice and swine models of postinfarction LV remodeling. The proportion of cells that expressed cell cycle markers (Ki67; BrdU; Aurora B and PH3) was significantly greater in CHIR99021+FGF1 treatment group than CHIR99021, FGF1 and PBS treatment group. The proportion of apoptotic cells was significantly smaller in CHIR99021+FGF1 treatment group than in groups of control, VEGF, CHIR99021, or FGF1 treatment alone. Conclusions: CHIR99021 and FGF synergistically activate cell cycle and reduce apoptosis, which accompanied by a significant improvement of cardiac function.