Dose-independent threshold illumination for non-invasive time-lapse fluorescence imaging of live cells

Developing a multi-functional sensor for cell traction force, matrix remodeling and biomechanical assays in self-assembled 3D tissues in vitro

“…There are a few computational methods, such as kinematics-based mean deformation metrics (MDM) 32 , nite element based approach 33 that can estimate cell generated deformation and thus approximate forces in 3D. However, limitations of these methods include the assumptions of constitutive equations (stress-strain relations), computationally expensive analysis and/or use of uorescent lights with damaging intensities 34 . Our protocol is free from these drawbacks.…”

3D Printed Ti3C2TxMXene/PCL Scaffolds for Guided Neuronal Growth and Photothermal Stimulation

“…Laser pulses can stimulate action potentials, but the optical energies and intensities must be kept sufficiently low to avoid damaging the tissue. The optical intensity for photodamage or phototoxicity in cells is substantially higher for red light (wavelength near 640 nm) than at blue, green, and ultraviolet wavelengths [20][21][22]. Wäldchen, S. et al[20] show that intensity limit of photodamage is in excess of 10 MW/m 2 for a wavelength of 640 nm, while Emon, B. et al[21] recommends 57 W/m 2 as a safe threshold for cell force homeostasis and Dubois, A. et al[22] observed that 0.2 MW/m 2 did not cause cellular damage in tissues.…”

“…Laser pulses can stimulate action potentials, but the optical energies and intensities must be kept sufficiently low to avoid damaging the tissue. The optical intensity for photodamage or phototoxicity in cells is substantially higher for red light (wavelength near 640 nm) than at blue, green, and ultraviolet wavelengths [20][21][22]. Wäldchen, S. et al[20] show that intensity limit of photodamage is in excess of 10 MW/m 2 for a wavelength of 640 nm, while Emon, B. et al[21] recommends 57 W/m 2 as a safe threshold for cell force homeostasis and Dubois, A. et al[22] observed that 0.2 MW/m 2 did not cause cellular damage in tissues.To stimulate with lower pulse energies and high spatial specificity, light absorbing particles, such as 3D fuzzy graphene [23], transition metal carbide/nitride (MXene) flakes [24], as well as gold or carbon nanoparticles [19], are incorporated onto the neurons to increase the photothermal conversion efficiency in localized regions of the cells.…”