Quantitative polarization-sensitive super-resolution solid immersion microscopy reveals biological tissues' birefringence in the terahertz range.

Terahertz (THz) technology offers a variety of applications in label-free medical diagnosis and therapy, majority of which rely on the effective medium theory that assumes biological tissues to be optically isotropic and homogeneous at the scale posed by the THz wavelengths. Meanwhile, most recent research discovered mesoscale ([Formula: see text]) heterogeneities of tissues; [Formula: see text] is a wavelength. This posed a problem of studying the related scattering and polarization effects of THz-wave-tissue interactions, while there is still a lack of appropriate tools and instruments for such studies.

PEG-fibrin conjugates: the PEG impact on the polymerization dynamics.

Fibrin and its modifications, particularly those with functionalized polyethylene glycol (PEG), remain highly attractive as a biomaterial in drug delivery and regenerative medicine. Despite the extensive knowledge of fibrinogenesis, there is little information on the processes occurring after its modification. Previously, we found structural differences between native fibrin and its conjugates with PEG that allows us to hypothesize that a combination of methods such as terahertz (THz) pulsed spectroscopy and rheology may contribute to the characterization of gelation and reveal the effect of PEG on the polymerization dynamics.

Moisture adsorption by decellularized bovine pericardium collagen matrices studied by terahertz pulsed spectroscopy and solid immersion microscopy.

In this paper, terahertz (THz) pulsed spectroscopy and solid immersion microscopy were applied to study interactions between water vapor and tissue scaffolds-the decellularized bovine pericardium (DBP) collagen matrices, in intact form, cross-linked with the glutaraldehyde or treated by plasma. The water-absorbing properties of biomaterials are prognostic for future cell-mediated reactions of the recipient tissue with the scaffold. Complex dielectric permittivity of DBPs was measured in the 0.

Terahertz dielectric spectroscopy and solid immersion microscopy of glioma model 101.8: brain tissue heterogeneity.

Terahertz (THz) technology holds strong potential for the intraoperative label-free diagnosis of brain gliomas, aimed at ensuring their gross-total resection. Nevertheless, it is still far from clinical applications due to the limited knowledge about the THz-wave-brain tissue interactions. In this work, rat glioma model 101.

Terahertz dielectric spectroscopy of human brain gliomas and intact tissues : double-Debye and double-overdamped-oscillator models of dielectric response.

Terahertz (THz) technology offers novel opportunities in the intraoperative neurodiagnosis. Recently, the significant progress was achieved in the study of brain gliomas and intact tissues, highlighting a potential for THz technology in the intraoperative delineation of tumor margins. However, a lack of physical models describing the THz dielectric permittivity of healthy and pathological brain tissues restrains the further progress in this field.

Terahertz radiation and the skin: a review.

Significance: Terahertz (THz) radiation has demonstrated a great potential in biomedical applications over the past three decades, mainly due to its non-invasive and label-free nature. Among all biological specimens, skin tissue is an optimal sample for the application of THz-based methods because it allows for overcoming some intrinsic limitations of the technique, such as a small penetration depth (0.1 to 0.

In situ terahertz monitoring of an ice ball formation during tissue cryosurgery: a feasibility test.

Significance: Uncontrolled cryoablation of tissues is a strong reason limiting the wide application of cryosurgery and cryotherapy due to the certain risks of unpredicted damaging of healthy tissues. The existing guiding techniques are unable to be applied in situ or provide insufficient spatial resolution. Terahertz (THz) pulsed spectroscopy (TPS) based on sensitivity of THz time-domain signal to changes of tissue properties caused by freezing could form the basis of an instrument for observation of the ice ball formation.

Proof of concept for continuously-tunable terahertz bandpass filter based on a gradient metal-hole array.

A continuously-tunable terahertz (THz) bandpass filter based on the resonant electromagnetic-wave transmission through a metal-hole array featuring a gradually changing period was developed and fabricated on a silicon substrate using optical lithography. A gradient geometry of the metal-hole array yields a wide tunability of the filter transmission, when operating with a focussed THz beam. The filter was studied numerically, using the finite element method, and experimentally, using the THz pulsed spectroscopy.

Optimal hyperosmotic agents for tissue immersion optical clearing in terahertz biophotonics.

In this work, a thorough analysis of hyperosmotic agents for the immersion optical clearing (IOC) in terahertz (THz) range was performed. It was aimed at the selection of agents for the efficient enhancement of penetration depth of THz waves into biological tissues. Pulsed spectroscopy in the frequency range of 0.

Terahertz spectroscopy of gelatin-embedded human brain gliomas of different grades: a road toward intraoperative THz diagnosis.

We applied terahertz (THz)-pulsed spectroscopy to study ex vivo the refractive index and absorption coefficient of human brain gliomas featuring different grades, as well as perifocal regions containing both intact and edematous tissues. Glioma samples from 26 patients were considered and analyzed according to further histological examination. In order to fix tissues for the THz measurements, we applied gelatin embedding, which allows for sustaining their THz response unaltered, as compared to that of the freshly excised tissues.