myrCell SarcPaint Ventricular Cardiomyocytes

Automated extraction of Z-band profiles and quantitative measurement of sarcomere spacing from confocal images enabling deep learning-based segmentation and spatial mapping with automated AI assisted workflows. This model enables automated multi-scale quantification of sarcomere organisation, myofibril architecture, and contractile dynamics directly from live-cell images and videos, thus eliminating endpoint staining while supporting longitudinal phenotyping and high-content drug screening. 

Immunofluorescent staining of human iPSC-derived SarcPaint Ventricular Cardiomyocytes at 10 days post-thawing showing SarcPaint-tagged α-actinin (green) with co-localisation of cardiac troponin T (cTnT), cardiac troponin I (cTnI) or ventricular myosin light chain-2 (MLC2v); 60x magnification.

Immunofluorescent staining of human iPSC-derived SarcPaint Ventricular Cardiomyocytes at 10 days post-thawing showing SarcPaint-tagged α-actinin (green) with co-localisation of mitochondria (mtCOX2), N-cadherin or connexin 43 (Cx43); 60x magnification.

Representative images show live-cell imaging of sarcomere remodelling following mavacamten exposure. SarcPaint Ventricular Cardiomyocytes were imaged during culture and following treatment with mavacamten.

Control cardiomyocytes at days 3 and 7 show progressive organisation of sarcomeric Z-bands (images a and b); treatment with 1 and 10 µM mavacamten at day 7 produces concentration-dependent alterations in sarcomere architecture, with increasing disruption of the organised Z-band pattern at higher exposure (c and d).

Representative video show live-cell imaging of sarcomere remodelling following mavacamten exposure. SarcPaint Ventricular Cardiomyocytes were imaged during culture and following treatment with mavacamten.

The video shows real-time time-lapse of sarcomeric changes on compound exposure. The endogenous ACTN2-Citrine reporter (SarcPaint) enables direct visualisation of these structural changes in live cardiomyocytes, providing a non-invasive approach for longitudinal assessment of drug-induced sarcomere remodelling and contractile phenotypes.

Control cardiomyocytes at days 3 and 7 show progressive organisation of sarcomeric Z-bands (images a and b); treatment with 1 and 10 µM mavacamten at day 7 produces concentration-dependent alterations in sarcomere architecture, with increasing disruption of the organised Z-band pattern at higher exposure (c and d).

Representative small-scale phenotypic screening workflow using SarcPaint Ventricular Cardiomyocytes. Cells were seeded into 384-well imaging plates and cultured for 10 days post-thaw before compound treatment (A).

Live cardiomyocytes were screened against a targeted library of 377 calcium channel-modulating compounds and imaged using the CellVoyager CV8000 High-Content Screening System (Yokogawa) (left).

AI-assisted image analysis quantified multiple structural and functional phenotypic parameters, including sarcomere organisation, myofibrillar integrity, cell morphology, and contractile behaviour. Compounds were subsequently classified based on their effects on α-actinin-positive sarcomeric architecture, enabling discrimination of beneficial, neutral, and toxic phenotypes and prioritisation of candidate molecules for downstream functional validation (B).

Representative pharmacological characterisation of SarcPaint Ventricular Cardiomyocytes. Cells were cultured on Matrigel-coated plates for 10 days post-thaw and treated with reference compounds targeting distinct cardiac signalling pathways. Live imaging was used to quantify beating rate.

Positive chronotropic agents, including phenylephrine (red) and isoprenaline (green) increased beating frequency, whereas mavacamten (blue) and verapamil (pink) reduced contractile amplitude and beating activity.

These data demonstrate that SarcPaint Ventricular Cardiomyocytes are sensitive to pharmacological modulation, confirming their suitability for functional drug screening.

SarcPaint Ventricular Cardiomyocytes were combined with fibroblasts in a collagen-based hydrogel and cast into myrPlates to generate Engineered Heart Muscle (EHM). Cardiomyocytes were maintained for 7-10 days post thaw culture before tissue casting. Live video-optical tracking using automated pole detection and peak analysis in the myrImager platform enabled longitudinal assessment of the tissue contractility throughout maturation.

Representative video of EHM contractility at day 35 of culture.

SarcPaint Ventricular Cardiomyocytes were combined with fibroblasts in a collagen-based hydrogel and cast into myrPlates to generate Engineered Heart Muscle (EHM). Cardiomyocytes were maintained for 7-10 days post-thaw culture before tissue casting. Live video-optical tracking using automated pole detection and peak analysis in the myrImager platform enabled longitudinal assessment of the tissue contractility throughout maturation.

Immunofluorescent imaging of whole EHM mount staining at day 21 (right); a cross section of EHM at day 28 (left). Together the images show well-aligned cardiomyocytes with organised sarcomeres and interspersed fibroblasts.

Longitudinal video-optical contractility measurements of 16 tissues over 58 days of culture, demonstrate progressive improvement in force of contraction (FOC) indicative of tissue maturation (A).

Contractile analysis under isometric conditions allowing deep phenotyping of contractility at the study endpoint from tissues at day 58 showing tissue elasticity and increased force development (B).

Data shown as mean ± SEM, n=8.

Engineered Heart Muscle (EHM) generated from wild-type Ventricular Cardiomyocytes (WT-vCM) and SarcPaint Ventricular Cardiomyocytes (WT-vCM SarcPaint) show comparable function at similar maturation age. The data shows contractile analysis of WT-vCM at day 42 and WT-vCM SarcPaint at day 58 under isometric conditions.