5 research outputs found
The role of tissue fluorescence in in vivo optical bioimaging
The following article appeared in Journal of Applied Physics 128.17 (2020): 171101 and may be found at https://doi.org/10.1063/5.0021854The technological advancements made in optics and semiconductors (e.g., cameras and laser diodes) working with infrared have brought interest in optical bioimaging back to the forefront of research investigating in vivo medical imaging techniques. The definition of the near-infrared transparency windows has turned optical imaging into more than just a method for topical imaging applications. Moreover, this has focused attention back to tissue fluorescence, emissions by tissues and organs that occur when excited by external illumination sources. Most endogenous fluorophores emit in the blue to green range of the electromagnetic spectrum and the resulting tissue fluorescence can be employed in studies from cells to tissue metabolism or avoided by shifting to the red if seen as unwanted autofluorescence. With the more recent move to infrared, it was discovered that autofluorescence is not limited to the visible but also strongly affects in vivo imaging in the infrared. In this Tutorial, we give an overview on tissue fluorescence and tissue interactions with excitation light as well as their effect on in vivo imaging. Furthermore, potential sources of tissue fluorescence in the near-infrared are identified and we describe approaches for successful biomedical imaging in the biological windows, taking into consideration infrared autofluorescence and summarizing techniques for avoiding it in in vivo imaging experimentsThis work was supported by the Spanish Ministry of Economy and Competitiveness under Project No. MAT2016-75362-C3-1-R,
the Spanish Ministry of Sciences, Innovation and Universities under Project No. PID2019-106211RB-I00 (NANONERV), by the
Instituto de Salud Carlos III (Nos. PI16/00812 and PI19/00565), and through the Comunidad Autónoma de Madrid (No. B2017/
BMD-3867RENIMCM), and co-financed by the European Structural and investment fund. Additional funding was provided by the
European Union’s Horizon 2020 FET Open project NanoTBTech (Grant Agreement No. 801305), the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal under Project No. IMP18_38(2018/0265), and also COST action CA17140. Y.S. acknowledges a scholarship from the China Scholarship Council (No.201806870023), E.X. is grateful for a Juan de la Cierva Formación scholarship (No. FJC2018-036734-I), and D.H.O. is thankful to the Instituto de Salud Carlos III for a Sara Borrell Fellowship (No. CD17/00210). The authors thank Dr. Blanca del Rosal for the helpful discussion and input on the manuscrip
The near-infrared autofluorescence fingerprint of the brain
This is the peer reviewed version of the following article: Lifante, J, del Rosal, B, Chaves-Coira, I, Fernández, N, Jaque, D, Ximendes, E. The near-infrared autofluorescence fingerprint of the brain. J. Biophotonics. 2020; 13:e202000154, which has been published in final form at https://doi.org/10.1002/jbio.202000154. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe brain is a vital organ involved in mostof the central nervous system disorders.Their diagnosis and treatment require fast,cost-effective, high-resolution and high-sensitivity imaging. The combinationof a new generation of luminescent nanoparticles and imaging systems work-ing in the second biological window (near-infrared II [NIR-II]) is emerging asa reliable alternative. For NIR-II imaging to become a robust technique at thepreclinical level, full knowledge of the NIR-II brain autofluorescence, responsi-ble for the loss of image resolution and contrast, is required. This work demon-strates that the brain shows a peculiar infrared autofluorescence spectrumthat can be correlated with specific molecular components. The existence ofparticular structures within the brain with well-defined NIR autofluorescencefingerprints is also evidenced, opening the door to in vivo anatomical imaging.Finally, we propose a rational selection of NIR luminescent probes suitable forlow-noise brain imaging based on their spectral overlap with brainautofluorescenceComunidad de Madrid, Grant/AwardNumber: B2017/BMD-3867RENIMCM;European Cooperation in Science andTechnology, Grant/Award Number:CA17140; Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal, Grant/Award Number:IMP18_38(2018/0265); Horizon 2020 Framework Programme, Grant/AwardNumber: 801305; Instituto de Salud CarlosIII, Grant/Award Number: PI16/00812;Ministerio de Ciencia, Innovación y Universidades, Grant/Award Number:FJC2018-036734-I; Ministerio deEconomía y Competitividad, Grant/AwardNumbers: MAT2016-75362-C3-1-R,MAT2017-83111R, MAT2017-85617-
In vivo grading of lipids in fatty liver by near-infrared autofluorescence and reflectance
The prevalence of nonalcoholic fatty liver
(NAFLD) is rapidly increasing worldwide.
When untreated, it may lead to complications such as liver cirrhosis or hepatocarcinoma. The diagnosis of NAFLD is usually
obtained by ultrasonography, a technique
that can underestimate its prevalence.
For this reason, physicians aspire for an
accurate, cost-effective, and noninvasive
method to determine both the presence
and the specific stage of the NAFLD. In this paper, we report an integrated
approach for the quantitative estimation of the density of triglycerides in the
liver based on the use of autofluorescence and reflectance signals generated by
the abdomen of obese C57BL6/J mice. Singular value decomposition is applied
to the generated spectra and its corresponding regression model provided a
determination coefficient of 0.99 and a root mean square error of 240 mg/dl.
This, in turn, enabled the quantitative imaging of triglycerides density in the
livers of mice under in vivo conditionsMinisterio de Ciencia e Innovacion,
Grant/Award Number: IJC2020-045229-I;
Ministerio de Ciencia e Innovacion,
Grant/Award Number:
NANONERVPID2019-106211RB-I0
3D Optical Coherence Thermometry Using Polymeric Nanogels
In nanothermometry, the use of nanoparticles as thermal probes enables
remote and minimally invasive sensing. In the biomedical context,
nanothermometry has emerged as a powerful tool where traditional
approaches, like infrared thermal sensing and contact thermometers, fall
short. Despite the strides of this technology in preclinical settings,
nanothermometry is not mature enough to be translated to the bedside. This
is due to two major hurdles: the inability to perform 3D thermal imaging and
the requirement for tools that are readily available in the clinics. This work
simultaneously overcomes both limitations by proposing the technology of
optical coherence thermometry (OCTh). This is achieved by combining
thermoresponsive polymeric nanogels and optical coherence tomography
(OCT)—a 3D imaging technology routinely used in clinical practice. The
volume phase transition of the thermoresponsive nanogels causes marked
changes in their refractive index, making them temperature-sensitive OCT
contrast agents. The ability of OCTh to provide 3D thermal images is
demonstrated in tissue phantoms subjected to photothermal processes, and
its reliability is corroborated by comparing experimental results with
numerical simulations. The results included in this work set credible
foundations for the implementation of nanothermometry in the form of OCTh
in clinical practiceThis work was financed by the Spanish Ministerio de Innovación y Ciencia under project NANONERV PID2019-106211RB-I00, NANOGRANZ
PID2021-123318OB-I00, PID2020-118878RB-I00, RYC2021-032913-I,
and TED2021-132317-I00B and under project COLUMNAS (PID2019-
110632RB-I00), by the Instituto de Salud Carlos III (PI19/00565), by
the Comunidad Autónoma de Madrid (S2022/BMD-7403 RENIM-CM
and SI3/PJI/2021-00211) and co-financed by the European structural
and investment fund. Additional funding was provided by COST action
CA17140, supported by COST (European Cooperation in Science and
Technology) and the Fundación para la Investigación Biomédica del
Hospital Universitario Ramón y Cajal (IMP21_A4 (2021/0427)
Early in vivo detection of denervation-induced atrophy by luminescence transient nanothermometry
Denervation induces skeletal muscle
atrophy due to the loss of control and
feedback with the nervous system. Unfortunately, muscle atrophy only becomes
evident days after the denervation event
when it could be irreversible. Alternative
diagnosis tools for early detection of
denervation-induced muscle atrophy are,
thus, required. In this work, we demonstrate how the combination of transient thermometry, a technique already
used for early diagnosis of tumors, and infrared-emitting nanothermometers
makes possible the in vivo detection of the onset of muscle atrophy at short
(<1 day) times after a denervation event. The physiological reasons behind
these experimental results have been explored by performing three dimensional numerical simulations based on the Pennes' bioheat equation. It is concluded that the alterations in muscle thermal dynamics at the onset of muscle
atrophy are consequence of the skin perfusion increment caused by the
alteration of peripheral nervous autonomous system. This work demonstrates
the potential of infrared luminescence thermometry for early detection of diseases of the nervous system opening the venue toward the development of new
diagnosis toolsComunidad de Madrid, Grant/Award
Number: S2017/BMD-3867 RENIM-CM;
COST action CA17140 (Nano2Clinic);
European Structural and Investment Fund
and the Ministerio de Economía y
Competitividad-MINECO, Grant/Award
Number: PID2019-106211RB-I00; Juan de
la Cierva scholarship, Grant/Award
Number: IJC2020-045229-