Refined fabrication of mechano-stimulating micro-platform for on-chip analyses of complex platelet behavior

Platelets can sense their surroundings as they crawl in search of optimal surface to adhere before activation, but the detailed mechanism has not been fully explored in different microenvironments. Herein, various aspects of platelet behavior, including morphology, movement and biomarker expression, were multilaterally examined on mechanically stimulating surfaces, with controlled rigidity and roughness, to elucidate the effect of microenvironment without chemical stimulus. The platelets demonstrated different movement behavior (e.g. back-and-forth and forward crawling), and motility, as well as varying degrees of spreading with lamellipodial and filopodial projections, based on varying mechanical microenvironments. Furthermore, after initial activation, the platelets all became stationary and the cell spreading became more prominent, while still maintaining their movement potential. P-selectin expression, along with α-granule and open canalicular system (OCS) distributions, all supported the morphological and movement behavior. These results strongly indicated that the mechanical microenvironment played a key role in the regulation of complex platelet activities.