The possibility of using silica-gold nanoshells with 150 nm silica core size and 25 thick gold shell as contrasting agents for optical coherence tomography (OCT) is analyzed. Experiments on agar biotissue phantoms showed that the penetration into increases intensity signal brightness corresponding areas OCT image. In vivo experiments rabbit skin demonstrated application onto provides significant borders between containing those without. This effect in manifested by increase superficial parts...

Abstract Background and Objective The goal of this study is to apply a new bioimaging modality, the Optical Coherence Tomography (OCT), for intraoperative control in laser surgery laryngeal carcinoma. Study Design/Materials Methods We studied 26 patients with carcinoma situ T 1 , 2 stage. used an endoscopic OCT device imaging at wavelength 0.83 μm acquisition rate approximately 0.5 frames/s single (200 × 200 pixel) tomogram. All were operated surgical YAG:Nd two switchable wavelengths 1.44...

A numerical algorithm based on a small-angle approximation of the radiative transfer equation (RTE) is developed to reconstruct scattering characteristics biological tissues from optical coherence tomography (OCT) images. According algorithm, tissue considered be layered random medium with set parameters in each layer: total coefficient, variance phase function, and probability backscattering, which fully describe OCT signal behavior versus probing depth. The reconstruction performed by...

Abstract KillerRed is known to be a unique red fluorescent protein displaying strong phototoxic properties. Its effectiveness has been shown previously for killing bacterial and cancer cells in vitro . Here, we investigated the photototoxicity of on tumor xenografts mice. HeLa Kyoto cell line stably expressing mitochondria fusion with histone H2B was used. Irradiation tumors 593 nm laser led photobleaching indicating photosensitization reaction caused significant destruction activation...

To evaluate the dose-time dependences of structural changes occurring in collagen within 24 hours to three months after gamma-irradiation at doses from 2-40 Gy vivo.Rat's tail tendon was chosen as vivo model, with its highly ordered structure allowing be interpreted unambiguously. Macromolecular level (I) investigated by differential scanning calorimetry (DSC); fibers and bundles (II) laser microscopy (LSM), bulk tissue microstructural (III) cross-polarization optical coherence tomography...

An experimental standard optical coherence tomography (OCT) setup that can be easily modified for cross-polarization OCT (CP OCT) operation has been developed to perform differential diagnosis of pathological tissues. The complementary use CP OCT, a technique provides map backscattering properties an object being studied by means low-coherence interferometry, and imaging improves the specificity diagnostics changes occurring in It is shown healthy, neoplastic scar tissues esophagus have...

An experimental setup for multicolor frequency-domain diffuse optical tomography (FD DOT) was created to visualize neoplasia of breast tissue and estimate its size. The is gently pressed between two glass plates scanned in the transilluminative configuration by a single source detector pair. Illumination at three wavelengths (684 nm, 794 850 nm) which correspond different parts absorption spectrum therapeutic transparency window provides information about concentration main absorbers...

Abstract Modern optical diagnostic techniques often require deformations of the studied biotissues for image acquisition. This paper discusses effect mechanical compression on formation OCT images human skin. The study was performed in vivo volunteers different age. We show that application to skin induces changes properties sample associated with elasticity layers. These induce an increase contrast interlayer boundaries. Further causes appearance dark areas obtained, likely interstitial or...

An experimental setup for combined photoacoustic (PA) and optically mediated ultrasound (US) microscopy is presented. A spherically focused 35 MHz polyvinylidene fluoride (PVDF) ultrasonic detector with a numerical aperture of 0.28, focal distance 9 mm, bandwidth (−6 dB level) 24 was used to obtain PA US data 3 mm imaging depth. fiber-optic system employed deliver laser excitation pulses from tunable the studied medium. single optical pulse form both A-scans. The probing were generated...

Antimicrobial photodynamic therapy (aPDT) was demonstrated to be effective against various species of Gram-positive bacteria. However, the complex structure a Gram-negative bacteria envelope limits application aPDT. Thus, goal this study improve efficiency antimicrobial with Fotoditazin uropathogenic The non-ionic detergent Triton X-100 and emulsifier Tween 80 were tested. effect extracellular photosensitizer on aPDT efficacy analyzed. Moreover, irradiation regime optimized in terms output...

The purpose of this study was to evaluate photobleaching the genetically encoded photosensitizer KillerRed in tumor spheroids upon pulsed and continuous wave (CW) laser irradiation analyze mechanisms cancer cell death after treatment. We observed light‐dose dependent mechanism over a wide range fluence rates. Loss fluorescence limited 80% at light doses 150 J/cm 2 more. Based on bleaching curves, six PDT regimes were applied for using CW power density 160 mW/cm 140 , 170 200 . Irradiation...

The problems of controlling the processes generation acoustic waves and microbubbles at optical fiber tip moderate-power surgical lasers with wavelengths 1.9 µm 0.97 using active passive methods are considered. It is shown that various sizes can be detected an ultrasound method, in which interaction area recorded simultaneously two frequencies. By measuring noise a receiving transducer ultrasonic locator, we determine frequency range signals occurring when large diameter bubbles, including...

A fluorescence diffuse tomography (FDT) setup for monitoring tumor growth in small animals has been created. In this an animal is scanned the transilluminative configuration by a single source and detector pair. To remove stray light detection system, we used combination of interferometric absorption filters. reduce scanning time, experimental was using following algorithm: (1) large-step to obtain general view (source move synchronously); (2) selection fluorescing region; (3) small-step...

Objective The goal of the described study was complex assessment age‐specific morphofunctional features skin different anatomic localization using optical coherence tomography ( OCT ). Methods Forty‐three healthy volunteers aging from 4 to 74 years were enrolled in study. Optical and functional parameters studied 18 areas human body. All classified as open closed, depending on external impact. Structural determined by means device equipped with a removable, flexible probe microscanner...

We present a theoretical model for laser cutting of biological tissue by strongly heated fiber tip with highly absorbing coating.A significant dependence the speed and depth on inclination angle scalpel to surface when scattering exceeds absorption in is shown.Experimental evidences this effect are presented.In experiment, we used silica coating made carbon silicon organic varnish, 0.97-µm wavelength porcine skin.The additional opportunity increase efficiency deposition layer considered.

Abstract The goal of this study is the development a method local laser hyperthermia with gold nanoparticles under noninvasive optical monitoring nanoparticle accumulation in tumor tissue vivo . Bifunctional plasmon resonant that are optimal for OCT diagnostics and heating at wavelength 810 nm were used study. examination showed invading into skin was maximal 4–5 h after intravenous injection. It demonstrated allowed more enhanced thermal sensitivity tissue. Laser heated up to 44–45 °C...

ABSTRACT The purpose of this study was to characterize essential changes in the structure annulus fibrosus (AF) after hydrothermal and infrared (IR) laser treatment correlate these results with alterations tissue state. Polarization‐sensitive optical coherence tomography imaging used measure collagen birefringence AF. Differential scanning calorimetry as a complementary technique, providing detailed information on thermodynamic processes tissue. Birefringence, peak denaturation endotherm,...

The goal of the study is comparative analysis layers in OCT images and morphological structure skin with thick thin epidermis.We analyzed difference between epidermis two ways. first approach consisted determination thicknesses different localizations from experimental images. second was to develop numerical models fitting based on Monte Carlo simulations revealing optical parameters epidermis.The correspondence confirmed. healthy comprise three case four epidermis. image zone transition...

The strong phototoxicity of the red fluorescent protein KillerRed allows it to be considered as a potential genetically encoded photosensitizer for photodynamic therapy (PDT) cancer. advantages over chemical photosensitizers are its expression in tumor cells transduced with appropriate gene and direct killing through precise damage any desired cell compartment. ability affect division induce death has already been demonstrated cancer lines vitro HeLa xenografts vivo. However, further...

The number of in vitro experimental studies was carried out with the use intact tissues to establish a mechanism laser-tissue interaction. However, process degeneration, both biochemical composition and behavior disc were altered drastically. objective this study evaluate role main matrix components laser modification annulus fibrosus (AF) under IR irradiation.The samples AF motion segment after hyaluronidase treatment, trypsin digestion glycation by glyceraldehyde heated hydrothermal bath...

Urinary tract infection (UTIs) aremainly caused by a number of anatomical and physiological dysfunctions, but there are also some iatrogenic factors, including the use certain medications, that contribute to development UTIs. The virulence bacteria colonize urinary may be modified pH presence soluble substances in urine, such as norepinephrine (NE) glucose. In this work, we studied influence NE glucose across range pHs (5, 7, 8) on biomass, matrix production metabolism uropathogenic strains...