This review focuses on classifying different types of long wavelength absorbing BODIPY dyes based on the wide range of structural modification methods that have been adopted, and on tabulating their spectral and photophysical properties. The structure-property relationships are analyzed in depth with reference to molecular modeling calculations, so that the effectiveness of the different structural modification strategies for shifting the main BODIPY spectral bands to longer wavelengths can be readily compared, along with their effects on the fluorescence quantum yield (ΦF) values. This should facilitate the future rational design of red/NIR region BODIPY dyes for a wide range of different applications.

Cellular and ionic causes of variability in the electrophysiological activity of hearts from individuals of the same species are unknown. However, improved understanding of this variability is key to enable prediction of the response of specific hearts to disease and therapies. Limitations of current mathematical modeling and experimental techniques hamper our ability to provide insight into variability. Here, we describe a methodology to unravel the ionic determinants of intersubject variability exhibited in experimental recordings, based on the construction and calibration of populations of models. We illustrate the methodology through its application to rabbit Purkinje preparations, because of their importance in arrhythmias and safety pharmacology assessment. We consider a set of equations describing the biophysical processes underlying rabbit Purkinje electrophysiology, and we construct a population of over 10,000 models by randomly assigning specific parameter values corresponding to ionic current conductances and kinetics. We calibrate the model population by closely comparing simulation output and experimental recordings at three pacing frequencies. We show that 213 of the 10,000 candidate models are fully consistent with the experimental dataset. Ionic properties in the 213 models cover a wide range of values, including differences up to ±100% in several conductances. Partial correlation analysis shows that particular combinations of ionic properties determine the precise shape, amplitude, and rate dependence of specific action potentials. Finally, we demonstrate that the population of models calibrated using data obtained under physiological conditions quantitatively predicts the action potential duration prolongation caused by exposure to four concentrations of the potassium channel blocker dofetilide.cardiac electrophysiology | computational biology | mathematical modeling | systems biology | drug B iological variability is exhibited at all levels in all organs of living organisms. It manifests itself as differences in physiological function between individuals of the same species and often more drastically by significant differences in the outcome of their exposure to pathological conditions. Thus, healthy cardiac cells of the same species and location exhibit a qualitatively similar response to a stimulus, i.e., the action potential (AP). However, significant quantitative intersubject differences exist in AP morphology and duration, which may explain the different individual response of each of the cells (and patients) to disease or drug action.The variability underlying the physiological and pathological responses of different individuals has often been ignored in experimental and theoretical research, ultimately hampering the extrapolation of results to a population level. Experimentalists often average the results obtained in different preparations to reduce experimental error, therefore also averaging out the effects of intersubject variation and resulting in an important loss of information. T...