Human fibronectin fn

Human iPS-CM tissues: Fully assembled devices with micro-molded cantilevers were sterilized using UV-Ozone. Subsequently, wells were incubated with a 50 µg/ml solution of human Fibronectin (FN, BD biosciences) in PBS, for at least 1 h. After removal of the FN solution, hiPS-CMs (Cor4U, Axiogenesis, Germany) were seeded at ~200 k/cm2 in designated Commercial Cor4U media (Axiogenesis, Germany). Cor4U media was changed every 2 days.
Neonatal Rat Ventricular Myocyte tissues: Non-molded devices were sterilized using UV-Ozone. FN line patterns (15 µm×4 µm) were micro-contact printed onto cantilevers using previously established procedures^{12 (link)}. Primary NRVMs were seeded at a density of ~140 k/cm2 in 10 % FBS in media 199 (Lonza). Cell media was replaced every 2 days, applying 2 % FBS in media 199 (Lonza). NRVMs were obtained from newborn Sprague Dawley rats (n ≥ 10 litters, per harvest) following procedures approved by the Harvard University Animal Care and Use Committee; the Institutional Animal Care and Use Committee (IACUC). The procedures follow "US Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training", the Guide for the Care and Use of Laboratory Animals 8th Ed., the Animal Welfare Act/Regulations, as well as other federal, state and city laws and regulations.

Prior to cell seeding, polycarbonate Transwell® inserts with 0.4 µm pores (Corning) were incubated with 50 µg/mL human fibronectin (FN, BD biosciences) in PBS for 2 h and inserts were rinsed twice with PBS. Human umbilical vein endothelial cells (ATCC) were seeded at a density of ~75 k/cm² in commercial endothelial growth media and supplements containing 2 % FBS (Lonza). Media was changed daily and exchanged to reduced serum media containing 0.5 % FBS on day 3 and 4.