Monitoring of temperature-mediated adipose tissue phase transitions by refractive-index measurements

Yanina, Irina Yu.; Попов, А. П.; Bykov, Alexander; Tuchin, Valery V.

doi:10.1117/12.2083679

Cited by 4 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where n 0 is the RI for temperature of 0°C; dn∕dT is the temperature increment,°C −1 ; and T is the current temperature,°C . 111,112,114,115,119 The average across all wavelengths from 480 to 1550 nm RI temperature increment dn∕dT equals to −ð3.54 AE 0.15Þ × 10 −4°C−1 with n 0 ¼ 1.4833 (see Table 3) that correlates well with the slope measured for oleic acid, −3.8 × 10 −4°C−1 with n 0 ¼ 1.467. 117 This can be explained by the high content of oleic acid in human fat (46%) and its low-melting temperature (16°C).…”

Section: Tissue Approximationsupporting

confidence: 60%

“…110 The refractometric properties of biological tissues and their individual components, such as human, porcine, and rat AT, porcine muscle tissue, rat brain tissue, and the main blood proteins-hemoglobin and albumin, have been studied in a wide range of wavelengths and temperatures. [111][112][113][114][115][116][117][118] The temperature dependences of RIs were analyzed for the presence of critical points corresponding to phase transitions. Figure 4 shows temperature dependence for the mean RI for abdominal human AT measured using multiwavelength Abbe refractometer DR-M2/1550 (Atago, Japan) at 930 nm and Table 1 The approximations for wavelength dependence of reduced scattering coefficient in the spectral range from 400 to 1300 nm for selected tissues.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of tissue optical properties in the context of tissue optical clearing

et al. 2018

View full text Add to dashboard Cite

Nowadays, dynamically developing optical (photonic) technologies play an ever-increasing role in medicine. Their adequate and effective implementation in diagnostics, surgery, and therapy needs reliable data on optical properties of human tissues, including skin. This paper presents an overview of recent results on the measurements and control of tissue optical properties. The issues reported comprise a brief review of optical properties of biological tissues and efficacy of optical clearing (OC) method in application to monitoring of diabetic complications and visualization of blood vessels and microcirculation using a number of optical imaging technologies, including spectroscopic, optical coherence tomography, and polarization- and speckle-based ones. Molecular modeling of immersion OC of skin and specific technique of OC of adipose tissue by its heating and photodynamic treatment are also discussed.

show abstract

Section: Tissue Approximationsupporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Measurement of tissue optical properties in the context of tissue optical clearing

et al. 2018

View full text Add to dashboard Cite

show abstract

“…16,17 Measurements of the temperature-dependence of the refractive index (RI) can be used for the detection of phase transitions in the AT. 21,22 The knowledge of thermal response of RI of AT including increments and phase transitions is important for getting a more accurate information on fat cell destruction pathways at laser heating [11][12][13] or cell lipolysis induced by a low-level laser therapy. 14 There are not many studies on RI of AT, especially in the course of tissue heating, available in the literature.…”

Section: Introductionmentioning

confidence: 99%

Monitoring of temperature-mediated phase transitions of adipose tissue by combined optical coherence tomography and Abbe refractometry

et al. 2018

View full text Add to dashboard Cite

Observation of temperature-mediated phase transitions between lipid components of the adipose tissues has been performed by combined use of the Abbe refractometry and optical coherence tomography. The phase transitions of the lipid components were clearly observed in the range of temperatures from 24°C to 60°C, and assessed by quantitatively monitoring the changes of the refractive index of 1- to 2-mm-thick porcine fat tissue slices. The developed approach has a great potential as an alternative method for obtaining accurate information on the processes occurring during thermal lipolysis.

show abstract

“…Since these changes were induced inside tissue, it is very important to continuously monitoring the internal temperature of the tumor to understand its evolution over time. The difference between the superficial and internal temperature [465], also observed in Monte Carlo simulations (Figure 7.17), could be interstitially measured by diffuse optics [466], photo-acoustics [467] or refractive index-based [468] systems, integrated as a theranostic probe [469]. This information could be used to adapt the illumination strategy in real time or to describe the unchained biological mechanism during therapy.…”

Section: Discussionmentioning

confidence: 80%

From cells to tissues, microscopy to modeling: towards precise, data-driven photothermal therapy with gold nanorods

Morales Dalmau

View full text Add to dashboard Cite

Suspensions of gold nanorods (GNRs) are emerging as potential drugs to address some of the limitations in traditional biomedical sensing,imaging and therapy. They are inorganic nanoparticles with good biocompatibility, with established protocols for flexible surface functionalization, with scalable production methods and with tunable light absorption. Of particular relevance for this thesis work, GNRs turn into efficient nano-sources of heat when illuminated at the wavelength of their maximum absorption peak, which is due to their longitudinal surface plasmon resonance (LSPR). This property has been exploited, for instance, in plasmonic photothermal therapy (PPTT) to produce controllable and localized cellular death. Nevertheless, the introduction of PPTT in the clinics has been slow owing to the complexity of its implementation involving biochemistry and physics across multiple scales and disciplines. Therefore, this work aimed at developing a set of tools capable to study, control and optimize the different mechanisms involved in PPTT, ranging from experiments on cell cultures to small animal models. By carrying out a systematic study with ten different types of GNRs in suspension. I have delimited the optimal shape and surface chemistry of GNRs for PPTT in terms of heating generation efficiency, cellular internalization and cytotoxicity. I have measured their heat generation over time at different laser powers and concentrations, and compared it with simulations. I have studied their accumulation in vitro and in vivo by developing a protocol to use two-photon luminescence microscopy as a quantitative tool, validated it against the standard inductively coupled plasma mass spectroscopy, and observed their toxicity over time. Then, I have developed a hybrid platform to study different in vivo PPTT conditions with integrated therapeutic and monitoring modules. The therapeutic module controlled the irradiation area, power density and exposure time of the laser emitting at the LSPR of GNRs. The monitoring module combined thermal imaging and non-invasive diffuse optical spectroscopy, including diffuse correlation and diffuse reflectance spectroscopies. In the specific case of murine renal tumors, the results have shown the feasibility using the hybrid, diffuse optical hand-held system to monitor changes of in vivo physiology under different PPTT conditions. I have quantified and related the significant physiological changes to post-therapy tumor volume and histology measurements, which has been validated with Monte Carlo simulations of photon propagation in tissues coupled to the three-dimensional solutions of the bioheat equation. With this work, I have laid the foundations towards personalized plasmonic photothermal therapy research on animals and its potential translation to humans. Les suspensions de nanocilindres d'or (GNRs, de gold nanorods en anglès) s'utilitzen en biomedicina com a fàrmac per ajudar a superar certes limitacions en els camp de la detecció, imatge i terapia. Els GNRs són nanopartícules inorgàniques dotades de bona compatibilitat biològica, amb protocols de funcionalització superficial establerts, de producció escalable i amb capacitat d'absorbir llum làser en un gran rang de longituds d'ona. En particular, els GNRs són magnífiques nano-fonts de calor quan s'irradien amb llum làser en la longitud d'ona amb màxima absorció, anomenada ressonància plasmònica (LSPR, de longitudinal surface plasmon resonance en anglès).Aquesta propietat s'ha utilitzat, per exemple, en teràpia plasmònica fototèrmica (PPTT, de plasmonic photothermal therapy en anglès) per produir mort cel·lular de forma controlada i localitzada. No obstant, la introducció de PPTT als hospitals ha sigut lenta degut a la seva complexitat a nivell bioquímic i fìsic, on hi ha implicades diferents escales i disciplines. En aquesta tesi s'explica com s'han desenvolupat un conjunt d'eines utilitzades per estudiar, optimitzar i controlar els diferents mecanismes de la PPTT, des del nivell cel·lular fins a petits animals de laboratori. A travèes d'un seguit d'estudis sistemàtics amb deu tipus de GNRs en suspensió, he delimitat la seva mida i química de superfície optima per la PPTT. He estudiat la generació de calor d'aquests GNRs sota diferents potències de làser i concentracions, i ho he comparat amb simulacions. Llavors, he estudiat la seva acumulació in vitro i in vivo tot desenvolupant un protocol per quanti_car imatges adquirides amb un microscopi de dos fotons, validat amb espectroscopia de massa de plasma induït, i quantificat la seva toxicitat en el temps. Llavors, he desenvolupat una plataforma híbrida que conté un mòdul terapèutic i un de monitorització per estudiar diferents condicions de PPTT in vivo. El mòdul terapèutic controla l'àrea d'irradiació, la densitat de potència i el temps d'exposició del làser terapèutic emetent en la LSPR dels GNRs. El mòdul de monitorització combina la imatge tèrmica amb l'espectroscopia no invasiva d'òptica difusa en un aparell en forma de bolígraf que inclou espectroscopia de correlacio difusa i espectroscopia de reectància difusa. En l'específic cas de ratolins amb xenografts ortotòpics de carcinoma de ronyó, els resultats mostren la utilitat del nostre sistema híbrid per monitoritzar els canvis fisiolòogics del tumor a diferents condicions de PPTT. He relacionat aquests canvis fisiològics durant la teràpia amb canvis post-teràpia, com són el volum tumoral i les mesures histològiques, i ho he validat amb simulacions 3D de Monte Carlo per determinar la propagació dels fotons en teixit, combinat amb l'equació de Penne per modelar els canvis fisiològics i el dany tissular. Amb aquesta tesi, he solidificat les bases cap a la teràpia plasmònica fototèrmica personalitzada en animals i he establert les bases per la seva translació en humans.

show abstract

Monitoring of temperature-mediated adipose tissue phase transitions by refractive-index measurements

Cited by 4 publications

References 11 publications

Measurement of tissue optical properties in the context of tissue optical clearing

Measurement of tissue optical properties in the context of tissue optical clearing

Monitoring of temperature-mediated phase transitions of adipose tissue by combined optical coherence tomography and Abbe refractometry

From cells to tissues, microscopy to modeling: towards precise, data-driven photothermal therapy with gold nanorods

Contact Info

Product

Resources

About