Cells cultured on flat surfaces and on dECM inserts were rinsed in PBS, lysed in 0.3 mL RIPA buffer (J52624, Thermo Fisher, Pittsburgh, PA, USA) diluted to 1X, and collected into microtubes followed by 90 sec of sonication (2 sec on, 4 sec off) using an ultrasonic homogenizer (Pulse 150, Benchmark Scientific, South Plainfield, NJ, USA).