Characterization of elastomeric scaffolds developed for tissue engineering applications by compression and nanoindentation tests, μ-Raman and μ-Brillouin spectroscopies

Abstract

In tissue engineering, porous biodegradable scaffolds are developed with morphological, chemical and mechanical properties to promote cell response. Therefore, the scaffold characterization at a (sub)micrometer and (bio)molecular level is paramount since cells are sensitive to the chemical signals, the rigidity, and the spatial structuring of their microenvironment. In addition to the analysis at room temperature by conventional quasi-static (0.1-45 Hz) mechanical tests, the ultrasonic (10 MHz) and µ-Brillouin inelastic light scattering (13 GHz) were used in this study to assess the dynamical viscoelastic parameters at different frequencies of elastomeric scaffolds. Time-temperature superposition principle was used to increase the high frequency interval (100 MHz-100 THz) of Brillouin experiments providing a mean to analyse the viscoelastic behavior with the fractional derivative viscoelastic model. Moreover, the µ-Raman analysis carried out simultaneously during the µ-Brillouin experiment, gave the local chemical composition.

Correlative Imaging of Motoneuronal Cell Elasticity by Pump and Probe Spectroscopy

“…In such a detection scheme, the BO decay time may be related to intrinsic attenuation associated to dynamical viscosity [12,29]. To unambiguously determine the Brillouin frequency and decay time, the cell should be thicker than the acoustic wavelength into the cell which is equal to half of the laser wavelength inside the cell, i.e.…”

The Use of Platelet-Rich Plasma to Promote Cell Recruitment into Low-Molecular-Weight Fucoidan-Functionalized Poly(Ester-Urea-Urethane) Scaffolds for Soft-Tissue Engineering

“…The scaffold chemical composition was monitored by Fourier-transformed infrared spectroscopy (FTIR Nicolet 380–Thermo Fisher Scientific, Waltham, MA, USA) in an attenuated total reflectance mode (ATR–Smart Omni Sampler, Thermo Fisher Scientific, Waltham, MA, USA) within the range 700–4000 cm −1 with a resolution of 4 cm −1 . The scaffold effective modulus of elasticity E 1 * was determined during compression in the axial direction to the foam rise with a 500 N force range, 7 mm displacement range and 5 mm min −1 testing speed, as previously described [35]. The scaffold number average molecular weight between cross-links M¯c was determined through the swelling measurements in toluene up to the swelling equilibrium, as previously described [35].…”

“…The scaffold effective modulus of elasticity E 1 * was determined during compression in the axial direction to the foam rise with a 500 N force range, 7 mm displacement range and 5 mm min −1 testing speed, as previously described [35]. The scaffold number average molecular weight between cross-links M¯c was determined through the swelling measurements in toluene up to the swelling equilibrium, as previously described [35]. The scaffold hydrophilicity/hydrophobicity was determined through the water contact angle measurements using a Digidrop Model DS GBX apparatus (GBX Scientific, Tallaght, Ireland) and Windrop++ software, and through the water uptake.…”

Brillouin Light Scattering: Applications in Biomedical Sciences

“…Finally, Brillouin scattering applied to biological and biomimetic matter, possibly supported by ultrasound and lower frequency viscoelastic probes, can help to tackle more complex viscoelastic scenari, such as poroelasticity 25 or soft glassy behavior. 21,30…”