Mr. Christian Zevallos-Delgado Profile

Christian Zevallos-Delgado

at Univ of Houston

SPIE Involvement:

Author

Publications (14)

SPIE Journal Paper | 18 September 2024 Open Access

Dual optical elastography detects TGF-β-induced alterations in the biomechanical properties of skin scaffolds

Taye T. Mekonnen, Yogeshwari S. Ambekar, Christian Zevallos-Delgado, Achuth Nair, Fernando Zvietcovich, Hoda Zarkoob, Manmohan Singh, Yi Wei Lim, Marc Ferrer, Salavat R. Aglyamov, Giuliano Scarcelli, Min Jae Song, Kirill V. Larin

JBO, Vol. 29, Issue 09, 095002, (September 2024) https://doi.org/10.1117/12.10.1117/1.JBO.29.9.095002

KEYWORDS: Skin, Tissues, Elastography, Biomechanics, Microscopy, Tissue optics, Elasticity, Collagen, Optical coherence tomography, Wave propagation

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SignificanceThe skin’s mechanical properties are tightly regulated. Various pathologies can affect skin stiffness, and understanding these changes is a focus in tissue engineering. Ex vivo skin scaffolds are a robust platform for evaluating the effects of various genetic and molecular interactions on the skin. Transforming growth factor-beta (TGF-β) is a critical signaling molecule in the skin that can regulate the amount of collagen and elastin in the skin and, consequently, its mechanical properties.AimThis study investigates the biomechanical properties of bio-engineered skin scaffolds, focusing on the influence of TGF-β, a signaling molecule with diverse cellular functions.ApproachThe TGF-β receptor I inhibitor, galunisertib, was employed to assess the mechanical changes resulting from dysregulation of TGF-β. Skin scaffold samples, grouped into three categories (control, TGF-β-treated, and TGF-β + galunisertib-treated), were prepared in two distinct culture media—one with aprotinin (AP) and another without. Two optical elastography techniques, namely wave-based optical coherence elastography (OCE) and Brillouin microscopy, were utilized to quantify the biomechanical properties of the tissues.ResultsResults showed significantly higher wave speed (with AP, p<0.001; without AP, p<0.001) and Brillouin frequency shift (with AP, p<0.001; without AP, p=0.01) in TGF-β-treated group compared with the control group. The difference in wave speed between the control and TGF-β + galunisertib with (p=0.10) and without AP (p=0.36) was not significant. Moreover, the TGF-β + galunisertib-treated group exhibited lower wave speed without and with AP and reduced Brillouin frequency shift than the TGF-β-treated group without AP, further strengthening the potential role of TGF-β in regulating the mechanical properties of the samples.ConclusionsThese findings offer valuable insights into TGF-β-induced biomechanical alterations in bio-engineered skin scaffolds, highlighting the potential of OCE and Brillouin microscopy in the development of targeted therapies in conditions involving abnormal tissue remodeling and fibrosis.

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Proceedings Article | 13 March 2024 Presentation

Multimodal elastography to evaluate the in vivo structure-function relationship of lens mechanics in presbyopia

Justin Schumacher, Leana Rohman, Christian Zevallos-Delgado, Marco Ruggeri, Jean-Marie Parel, Fabrice Manns, Kirill Larin, Giuliano Scarcelli

Proceedings Volume PC12824, PC128240Q (2024) https://doi.org/10.1117/12.3001919

KEYWORDS: In vivo imaging, Elastography, Mechanics, Visual process modeling, Microscopy, Eye, Data modeling, Visualization, Visual system, Therapeutics

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Proceedings Article | 13 March 2024 Presentation + Paper

High-resolution mapping of embryo mechanical properties during development with reverberant OCE

Manmohan Singh, Fernando Zvietcovich, Christian Zevallos-Delgado, Yogeshwari Ambekar, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12830, 128300W (2024) https://doi.org/10.1117/12.3000237

KEYWORDS: Optical coherence tomography, Windows, Imaging systems, Spine, Heart, Brain, Biological imaging, Vibration, Particles, Optical coherence

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Proceedings Article | 12 March 2024 Poster + Paper

Assessment of safe acoustic radiation force for crystalline lens optical coherence elastography in ex-vivo porcine eyes

Christian Zevallos-Delgado, Taye Mekonnen, Manmohan Singh, Justin Schumacher, Giuliano Scarcelli, Leana Rohman, Fabrice Manns, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12844, 128440D (2024) https://doi.org/10.1117/12.3002520

KEYWORDS: Acoustics, Crystalline lens, Optical coherence tomography, Elastography, Tissues, Optical coherence, Confocal microscopy, Wave propagation, Ultrasound transducers, Safety

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Proceedings Article | 12 March 2024 Poster + Paper

Comparison of optical coherence elastography techniques, Brillouin spectroscopy, and ultrasound elastography on samples with varying stiffness

Andres Bryan, Sajedeh Saeidi Fard, Christian Zevallos Delgado, Chaitanya Duvvuri, Achuth Nair, Manmohan Singh, Michael Twa, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12844, 128440B (2024) https://doi.org/10.1117/12.2692942

KEYWORDS: Elastography, Spectroscopy, Optical coherence tomography, Elasticity, Tissues, Optical coherence

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Proceedings Article | 12 March 2024 Presentation + Paper

Assessment of the biomechanical changes on zebrafish larvae eye development caused by phenylthiourea (PTU) treatment using reverberant optical coherence elastography (Rev-OCE)

Christian Zevallos-Delgado, Taye Mekonnen, Yogeshwari Ambekar, Manmohan Singh, Joshua Wythe, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12844, 1284406 (2024) https://doi.org/10.1117/12.3003390

KEYWORDS: Eye, Biomechanics, Optical coherence tomography, Optical coherence, Elastography, Thyroid, Windows, Transparency, In vivo imaging, Eye models

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SPIE Journal Paper | 11 September 2023 Open Access

Multifocal acoustic radiation force-based reverberant optical coherence elastography for evaluation of ocular globe biomechanical properties

Taye Mekonnen, Christian Zevallos-Delgado, Manmohan Singh, Salavat Aglyamov, Kirill Larin

JBO, Vol. 28, Issue 09, 095001, (September 2023) https://doi.org/10.1117/12.10.1117/1.JBO.28.9.095001

KEYWORDS: Cornea, Biomechanics, Eye, Elasticity, Acoustic waves, Sclera, Acoustics, Optical coherence tomography, Tissues, Iris

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SignificanceQuantifying the biomechanical properties of the whole eye globe can provide a comprehensive understanding of the interactions among interconnected ocular components during dynamic physiological processes. By doing so, clinicians and researchers can gain valuable insights into the mechanisms underlying ocular diseases, such as glaucoma, and design interventions tailored to each patient’s unique needs.AimThe aim of this study was to evaluate the feasibility and effectiveness of a multifocal acoustic radiation force (ARF) based reverberant optical coherence elastography (RevOCE) technique for quantifying shear wave speeds in different ocular components simultaneously.ApproachWe implemented a multifocal ARF technique to generate reverberant shear wave fields, which were then detected using phase-sensitive optical coherence tomography. A 3D-printed acoustic lens array was employed to manipulate a collimated ARF beam generated by an ultrasound transducer, producing multiple focused ARF beams on mouse eye globes ex vivo. RevOCE measurements were conducted using an excitation pulse train consisting of 10 cycles at 3 kHz, followed by data processing to produce a volumetric map of the shear wave speed.ResultsThe results show that the system can successfully generate reverberant shear wave fields in the eye globe, allowing for simultaneous estimation of shear wave speeds in various ocular components, including cornea, iris, lens, sclera, and retina. A comparative analysis revealed notable differences in wave speeds between different parts of the eye, for example, between the apical region of the cornea and the pupillary zone of the iris (p = 0.003). Moreover, the study also revealed regional variations in the biomechanical properties of ocular components as evidenced by greater wave speeds near the apex of the cornea compared to its periphery.ConclusionsThe study demonstrated the effectiveness of RevOCE based on a non-invasive multifocal ARF for assessing the biomechanical properties of the whole eyeball. The findings indicate the potential to provide a comprehensive understanding of the mechanical behavior of the whole eye, which could lead to improved diagnosis and treatment of ocular diseases.

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Proceedings Article | 27 March 2023 Presentation + Paper

A multifocal acoustic lens-transducer system for reverberant optical coherence elastography

Taye Mekonnen, Alexander Schill, Christian Zevallos-Delgado, Manmohan Singh, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12381, 123810B (2023) https://doi.org/10.1117/12.2650633

KEYWORDS: Acoustics, Imaging systems, Elastography, Acoustic waves, Gelatin, Tissues, Optical coherence, Elasticity, Wave propagation, Ultrasound transducers

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Proceedings Article | 15 March 2023 Presentation + Paper

Characterizing regional biomechanical properties of the porcine iris using optical coherence elastography

Taye Mekonnen, Christian Zevallos-Delgado, Babak Safa, Manmohan Singh, Salavat Aglyamov, C. Ross Ethier, Kirill Larin

Proceedings Volume 12381, 1238106 (2023) https://doi.org/10.1117/12.2651285

KEYWORDS: Elasticity, Iris recognition, Biomechanics, Iris, Acoustic waves, Optical coherence, Ultrasound transducers

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Proceedings Article | 15 March 2023 Paper

Multimodal optical elastography assessment of a murine collagen XII knockout

Achuth Nair, Yogeshwari Ambekar, Christian Zevallos-Delgado, Mei Sun, Manmohan Singh, Fernando Zvietcovich, Taye Mekonnen, Salavat Aglyamov, Manuel Koch, Giuliano Scarcelli, Edgar Espana, Kirill Larin

Proceedings Volume 12381, 123810F (2023) https://doi.org/10.1117/12.2661151

KEYWORDS: Cornea, Collagen, Elastography, Tissues, Microscopy, Tissue optics, Medicine, Biomechanics

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Proceedings Article | 15 March 2023 Paper

Assessing the biomechanical properties of embryos using reverberant optical coherence elastography (Rev-OCE)

Christian Zevallos-Delgado, Taye Tolu Mekonnen, Yogeshwari Ambekar, Fernando Zvietcovich, Manmohan Singh, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12381, 123810C (2023) https://doi.org/10.1117/12.2650958

KEYWORDS: Biomechanics, Optical coherence tomography, Elastography, Optical coherence, Particles, Imaging systems

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Proceedings Article | 8 March 2023 Presentation + Paper

High-resolution 3D biomechanical mapping of embryos with reverberant optical coherence elastography (Rev-OCE)

Christian Zevallos-Delgado, Yogeshwari Ambekar, Taye Mekonnen, Fernando Zvietcovich, Nadine Nijem, Manmohan Singh, Arne Lekven, Salavat Aglyamov, Kirill Larin

Proceedings Volume 12367, 123670P (2023) https://doi.org/10.1117/12.2650904

KEYWORDS: Biomechanics, Optical coherence tomography, Elastography, Nervous system, Tissues, Animals, Imaging systems

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Proceedings Article | 27 May 2022 Presentation + Paper

Optical coherence tomography guided Brillouin microscopy to study early embryonic development

Yogeshwari Ambekar, Manmohan Singh, Alexander Schill, Jitao Zhang, Christian Zevallos-Delgado, Behzad Khajavi, Salavat Aglyamov, Richard Finnell, Giuliano Scarcelli, Kirill Larin

Proceedings Volume 12144, 121440H (2022) https://doi.org/10.1117/12.2624346

KEYWORDS: Optical coherence tomography, Tissues, Microscopy, Imaging systems, Mirrors, Image resolution, Medicine, Spectroscopy, Optical microscopy, Multimodal imaging

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Proceedings Article | 2 March 2022 Poster + Paper

Assessment of the influence of lens capsule on lens biomechanical properties with optical coherence elastography

Taye Mekonnen, Christian Zevallos-Delgado, Hongqiu Zhang, Manmohan Singh, Salavat Aglyamov, Kirill Larin

Proceedings Volume 11962, 1196208 (2022) https://doi.org/10.1117/12.2610515

KEYWORDS: Dispersion, Phase velocity, Optical coherence tomography, Elastography, Coherence (optics), Acoustics, Wave propagation, Ultrasonography, Transducers, Protactinium

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Showing 5 of 14 publications

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