Investigating frequency-dependent viscoelastic spectra of the tumor microenvironment with wideband laser speckle rheological microscopy

Alterations in tissue mechanical properties have emerged as not merely a symptom of cancer but a decisive regulator of various oncogenic processes. The tumor microenvironment exhibits a combination of elastic and viscous traits spanning a wide frequency spectrum, leading to a perceived paradox of both matrix stiffening and 'liquidization' that coexist during malignant transformation and metastasis. Yet, seminal mechanobiological studies have largely relied on a single mechanical descriptor of elasticity. We present wideband laser Speckle rHEologicAl micRoscopy (SHEAR) to investigate the elastic and viscous spectral signatures that exist over >5 decades of frequencies in various types of clinical tumor specimens.