The contraction and relaxation of cardiomyocytes rely on periodic action potentials, a process closely associated with calcium. Impaired myocardial function is partly attributed to alterations in excitation-contraction coupling (ECC) function, leading to changes in the timing of intracellular Ca²⁺ release and reuptake as well as the intracellular Ca²⁺ content. In vitro experiments were conducted to investigate the mechanism underlying the rapid fluctuations in intracellular calcium concentration induced by inflammatory reactive oxygen species (ROS) in damaged cardiomyocytes. Treatment with SDF-1α@PUE significantly enhanced Ca²⁺ conduction, reduced the time required to reach the calcium peak, and increased the number of calcium pulses. Optical mapping experiments confirmed that the SDF-1α@PUE hydrogel-treated group exhibited the shortest calcium transient duration.

j. Schematic of the optical mapping system of the artificially changed longitudinal conduction pathway in the rat heart. k. The summary of longitudinal conduction velocity (CV) of 20 electrical signal conducting pathways from the rat hearts in different groups. Boxplots show the median and the first and third quartiles. l. Conduction velocity for rats after various treatments were collected and analyzed by the median. (n=20). Lines depict median and interquartile range.

b and c. The corresponding quantitative calcium_x0002_transient parameters of (b) time to peak and (c) peak number per 5 s (n=3). Data are shown as mean ± SD, and statistical analysis was performed with one-way ANOVA and Kruskal-Wallis statistic tests. d and e. The evaluation of the calcium transient duration at 90% (CTD90) and calcium conduction of sinus rhythm activation/apex stimulation by an optical mapping system

Advanced Materials (IF26.8)

https://doi.org/10.1002/adma.202302686