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Jennings CM, Markel AC, Domingo MJE, Miller KS, Bayer CL, Parekh SH. Collagen organization and structure in FLBN5-/- mice using label-free microscopy: implications for pelvic organ prolapse. bioRxiv 2024:2024.01.31.578106. [PMID: 38352586 PMCID: PMC10862878 DOI: 10.1101/2024.01.31.578106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Pelvic organ prolapse (POP) is a gynecological disorder described by the descent of superior pelvic organs into or out of the vagina as a consequence of disrupted muscles and tissue. A thorough understanding of the etiology of POP is limited by the availability of clinically relevant samples, restricting longitudinal POP studies on soft-tissue biomechanics and structure to POP-induced models such as fibulin-5 knockout (FBLN5-/-) mice. Despite being a principal constituent in the extracellular matrix, little is known about structural perturbations to collagen networks in the FBLN5-/- mouse cervix. We identify significantly different collagen network populations in normal and prolapsed cervical cross-sections using two label-free, nonlinear microscopy techniques. Collagen in the prolapsed mouse cervix tends to be more isotropic, and displays reduced alignment persistence via 2-D Fourier Transform analysis of images acquired using second harmonic generation microscopy. Furthermore, coherent Raman hyperspectral imaging revealed elevated disorder in the secondary structure of collagen in prolapsed tissues. Our results underscore the need for in situ multimodal monitoring of collagen organization to improve POP predictive capabilities.
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Affiliation(s)
- Christian M Jennings
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Andrew C Markel
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Mari J E Domingo
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Kristin S Miller
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
- Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, USA
- Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Sapun H Parekh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
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Vincely VD, Bayer CL. Functional Photoacoustic Imaging for Placental Monitoring: A Mini Review. IEEE Trans Ultrason Ferroelectr Freq Control 2023; 70:1642-1650. [PMID: 37030823 PMCID: PMC10539485 DOI: 10.1109/tuffc.2023.3263361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The placenta, a highly vascularized interface between the mother and fetus, undergoes dramatic anatomical and functional changes during pregnancy. These changes occur both during healthy development and adverse pathologies of pregnancy, such as preeclampsia (PE). Abnormal placental development can lead to life-long health impacts on both the mother and child. Photoacoustic (PA) imaging, extensively developed for preclinical imaging applications in oncology and cardiovascular disease, uses optical energy to generate acoustic waves through thermoelastic expansion of light-absorbing chromophores within tissue. Recently, PA imaging has been used to study preclinical placental anatomy and function. If clinical translation of PA imaging of the placenta is achieved, the impact on maternal-fetal health could be expansive. This perspective highlights the recent progress in PA imaging for placental monitoring and discusses the progress needed for human clinical translation.
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Huda K, Lawrence DJ, Thompson W, Lindsey SH, Bayer CL. In vivo noninvasive systemic myography of acute systemic vasoactivity in female pregnant mice. Nat Commun 2023; 14:6286. [PMID: 37813833 PMCID: PMC10562381 DOI: 10.1038/s41467-023-42041-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023] Open
Abstract
Altered vasoactivity is a major characteristic of cardiovascular and oncological diseases, and many therapies are therefore targeted to the vasculature. Therapeutics which are selective for the diseased vasculature are ideal, but whole-body selectivity of a therapeutic is challenging to assess in practice. Vessel myography is used to determine the functional mechanisms and evaluate pharmacological responses of vascularly-targeted therapeutics. However, myography can only be performed on ex vivo sections of individual arteries. We have developed methods for implementation of spherical-view photoacoustic tomography for non-invasive and in vivo myography. Using photoacoustic tomography, we demonstrate the measurement of acute vascular reactivity in the systemic vasculature and the placenta of female pregnant mice in response to two vasodilators. Photoacoustic tomography simultaneously captures the significant acute vasodilation of major arteries and detects selective vasoactivity of the maternal-fetal vasculature. Photoacoustic tomography has the potential to provide invaluable preclinical information on vascular response that cannot be obtained by other established methods.
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Affiliation(s)
- Kristie Huda
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Dylan J Lawrence
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
- Photosound Technologies Inc., Houston, TX, USA
| | | | - Sarah H Lindsey
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA.
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Manuel LD, Vincely VD, Bayer CL, McPeak KM. Monodisperse Sub-100 nm Au Nanoshells for Low-Fluence Deep-Tissue Photoacoustic Imaging. Nano Lett 2023; 23:7334-7340. [PMID: 37540682 PMCID: PMC10450810 DOI: 10.1021/acs.nanolett.3c01696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/29/2023] [Indexed: 08/06/2023]
Abstract
Nanoparticles with high absorption cross sections will advance therapeutic and bioimaging nanomedicine technologies. While Au nanoshells have shown great promise in nanomedicine, state-of-the-art synthesis methods result in scattering-dominant particles, mitigating their efficacy in absorption-based techniques that leverage the photothermal effect, such as photoacoustic (PA) imaging. We introduce a highly reproducible synthesis route to monodisperse sub-100 nm Au nanoshells with an absorption-dominant optical response. Au nanoshells with 48 nm SiO2 cores and 7 nm Au shells show a 14-fold increase in their volumetric absorption coefficient compared to commercial Au nanoshells with dimensions commonly used in nanomedicine. PA imaging with Au nanoshell contrast agents showed a 50% improvement in imaging depth for sub-100 nm Au nanoshells compared with the smallest commercially available nanoshells in a turbid phantom. Furthermore, the high PA signal at low fluences, enabled by sub-100 nm nanoshells, will aid the deployment of low-cost, low-fluence light-emitting diodes for PA imaging.
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Affiliation(s)
- Luis D.
B. Manuel
- Gordon
and Mary Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Vinoin Devpaul Vincely
- Department
of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Carolyn L. Bayer
- Department
of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Kevin M. McPeak
- Gordon
and Mary Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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Alencar AKN, Swan KF, Pridjian G, Lindsey SH, Bayer CL. Connecting G protein-coupled estrogen receptor biomolecular mechanisms with the pathophysiology of preeclampsia: a review. Reprod Biol Endocrinol 2023; 21:60. [PMID: 37393260 DOI: 10.1186/s12958-023-01112-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/20/2023] [Indexed: 07/03/2023] Open
Abstract
BACKGROUND Throughout the course of pregnancy, small maternal spiral arteries that are in contact with fetal tissue undergo structural remodeling, lose smooth muscle cells, and become less responsive to vasoconstrictors. Additionally, placental extravillous trophoblasts invade the maternal decidua to establish an interaction between the fetal placental villi with the maternal blood supply. When successful, this process enables the transport of oxygen, nutrients, and signaling molecules but an insufficiency leads to placental ischemia. In response, the placenta releases vasoactive factors that enter the maternal circulation and promote maternal cardiorenal dysfunction, a hallmark of preeclampsia (PE), the leading cause of maternal and fetal death. An underexplored mechanism in the development of PE is the impact of membrane-initiated estrogen signaling via the G protein-coupled estrogen receptor (GPER). Recent evidence indicates that GPER activation is associated with normal trophoblast invasion, placental angiogenesis/hypoxia, and regulation of uteroplacental vasodilation, and these mechanisms could explain part of the estrogen-induced control of uterine remodeling and placental development in pregnancy. CONCLUSION Although the relevance of GPER in PE remains speculative, this review provides a summary of our current understanding on how GPER stimulation regulates some of the features of normal pregnancy and a potential link between its signaling network and uteroplacental dysfunction in PE. Synthesis of this information will facilitate the development of innovative treatment options.
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Affiliation(s)
| | - Kenneth F Swan
- Department of Obstetrics & Gynecology, Tulane University, New Orleans, LA, 70112, USA
| | - Gabriella Pridjian
- Department of Obstetrics & Gynecology, Tulane University, New Orleans, LA, 70112, USA
| | - Sarah H Lindsey
- Department of Pharmacology, Tulane University, New Orleans, LA, 70112, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA.
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Lawrence DJ, Bayer CL. Photoacoustic imaging provides an in vivo assessment of the preeclamptic placenta remodeling and function in response to therapy. Placenta 2022; 126:46-53. [PMID: 35764022 PMCID: PMC10236486 DOI: 10.1016/j.placenta.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/16/2022] [Accepted: 06/17/2022] [Indexed: 11/24/2022]
Abstract
INTRODUCTION There is a lack of effective therapeutic interventions for preeclampsia. A central factor in the etiology of the disease is the development of placental hypoxia due to abnormal vascular remodeling. However, methods to assess the impact of potential therapies on placental growth and remodeling are currently lacking. Here, we develop and validate ultrasound-guided photoacoustic imaging methods to monitor the placental response to therapeutic intervention. Establishing non-invasive tools to image placental function opens up previously unachievable understandings of placental therapeutic response. METHODS Studies were performed in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. Preclinical research has identified tempol, a superoxide dismutase mimetic, and the phosphodiesterase inhibitor sildenafil as potential therapeutics for preeclampsia, as both improve in vivo maternal outcomes. PA images of the placental environment were acquired in RUPP rats receiving tempol (n = 8) or sildenafil (n = 8) to assess the longitudinal effects of treatment on placental oxygenation and vascular remodeling. Imaging measurements were validated with ex vivo histological analysis. RESULTS Spectral photoacoustic imaging non-invasively measured placental hypoxia and impaired vascular growth two days after the RUPP procedure was implemented. Sildenafil significantly improved (p < 0.05) placental oxygenation and promoted vascular remodeling in RUPP animals, while RUPP animals treated with tempol had a diminished placental therapeutic response. DISCUSSION We demonstrate that photoacoustic imaging provides in vivo measures of placental oxygenation and vascular remodeling, a previously unobtainable assessment of preeclamptic therapeutic response. These imaging tools have tremendous potential to accelerate the search for effective therapies for preeclampsia.
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Affiliation(s)
- Dylan J Lawrence
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA.
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Ogola BO, Clark GL, Abshire CM, Harris NR, Gentry KL, Gunda SS, Kilanowski-Doroh I, Wong TJ, Visniauskas B, Lawrence DJ, Zimmerman MA, Bayer CL, Groban L, Miller KS, Lindsey SH. Sex and the G Protein-Coupled Estrogen Receptor Impact Vascular Stiffness. Hypertension 2021; 78:e1-e14. [PMID: 34024124 PMCID: PMC8192475 DOI: 10.1161/hypertensionaha.120.16915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Benard O. Ogola
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
| | - Gabrielle L. Clark
- Tulane University, Department of Biomedical Engineering, New Orleans, LA, USA
| | - Caleb M. Abshire
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
| | | | - Kaylee L. Gentry
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
| | - Shreya S. Gunda
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
| | | | - Tristen J. Wong
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
| | | | - Dylan J. Lawrence
- Tulane University, Department of Biomedical Engineering, New Orleans, LA, USA
| | | | - Carolyn L. Bayer
- Tulane University, Department of Biomedical Engineering, New Orleans, LA, USA
| | - Leanne Groban
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Kristin S. Miller
- Tulane University, Department of Biomedical Engineering, New Orleans, LA, USA
| | - Sarah H. Lindsey
- Tulane University, Department of Pharmacology, New Orleans, LA, USA
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Huda K, Wu C, Sider JG, Bayer CL. Spherical-view photoacoustic tomography for monitoring in vivo placental function. Photoacoustics 2020; 20:100209. [PMID: 33101927 PMCID: PMC7569225 DOI: 10.1016/j.pacs.2020.100209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 05/04/2023]
Abstract
Photoacoustic tomography has great potential to image dynamic functional changes in vivo. Many tomographic systems are built with a circular view geometry, necessitating a linear translation along one axis of the subject to obtain a three-dimensional volume. In this work, we evaluated a prototype spherical view photoacoustic tomographic system which acquires a 3D volume in a single scan, without linear translation. We simultaneously measured relative hemoglobin oxygen saturation in multiple placentas of pregnant mice under oxygen challenge. We also synthesized a folate-conjugated indocyanine green (ICG) contrast agent to image folate kinetics in the placenta. Photoacoustic tomography performed at the wavelength of peak optical absorption of our contrast agent revealed increased ICG signal over time. Through these phantom and in vivo studies, we have demonstrated that the spherical view 3D photoacoustic tomographic system achieves high sensitivity and fast image acquisition, enabling in vivo experiments to assess physiological and molecular dynamics.
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Ogola BO, Clark GL, Abshire CM, Harris NR, Gentry KL, Lawrence D, Zimmerman MA, Bayer CL, Miller KS, Lindsey SH. Abstract P112: Sex Differences and the Role of G Protein-Coupled Estrogen Receptor in Arterial Stiffening. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pulse wave velocity (PWV) independently predicts cardiovascular events and is exacerbated in women following menopause. Since our previous work shows that G protein-coupled estrogen receptor (GPER) plays a protective role in the vasculature, the current study evaluated sex differences and the impact of GPER on arterial stiffening. We hypothesized that genetic deletion of GPER attenuates sex differences in arterial stiffness. Male and female wildtype (wt) and global GPER knockout (ko) mice (n=46) were used between 16-21 weeks of age. Ang II infusion (700 ng/kg/day for two weeks) was used to induce hypertension, and SBP was measured using tail cuff plethysmography. Local PWV within the carotid artery was obtained via high frequency ultrasound in both color Doppler and M-mode. The excised carotid was subjected to passive biaxial mechanical testing followed by four fiber family constitutive modeling. Statistical analysis was performed using two-way ANOVA with Sidak’s multiple comparisons test. Baseline SBP was significantly lower in females (P=0.035) but was not impacted by genotype. Baseline PWV was significantly higher in male versus female wt mice (P<0.01) but was not different in ko mice. Baseline axial (P<0.01) and circumferential (P=0.027) stiffness was higher in female wt mice but was not impacted by genotype. Ang II infusion significantly increased SBP (P<0.001) and PWV (P<0.001) in all groups, removing any impact of sex or genotype. Ang II increased axial stiffness and decreased diagonal collagen in male and female GPER ko mice. In conclusion, we found that GPER deletion did not impact blood pressure but removed sex differences in PWV. While female wt mice had the lowest PWV at baseline, genetic deletion of GPER or Ang II infusion removed this protection independent of BP. Therefore, local carotid PWV may provide information on vascular status independent of BP, and GPER plays an important role in vascular compliance and arterial stiffening.
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Lawrence DJ, Huda K, Bayer CL. Longitudinal characterization of local perfusion of the rat placenta using contrast-enhanced ultrasound imaging. Interface Focus 2019; 9:20190024. [PMID: 31485312 DOI: 10.1098/rsfs.2019.0024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2019] [Indexed: 01/04/2023] Open
Abstract
The placenta performs many physiological functions critical for development. Insufficient placental perfusion, due to improper vascular remodelling, has been linked to many pregnancy-related diseases. To study longitudinal in vivo placental perfusion, we have implemented a pixel-wise time-intensity curve (TIC) analysis of contrast-enhanced ultrasound (CEUS) images. CEUS images were acquired of pregnant Sprague Dawley rats after bolus injections of gas-filled microbubble contrast agents. Conventionally, perfusion can be quantified using a TIC of contrast enhancement in an averaged region of interest. However, the placenta has a complex structure and flow profile, which is insufficiently described using the conventional technique. In this work, we apply curve fitting in each pixel of the CEUS image series in order to quantify haemodynamic parameters in the placenta and surrounding tissue. The methods quantified an increase in mean placental blood volume and relative blood flow from gestational day (GD) 14 to GD18, while the mean transit time of the microbubbles decreased, demonstrating an overall rise in placental perfusion during gestation. The variance of all three parameters increased during gestation, showing that regional differences in perfusion are observable using the pixel-wise TIC approach. Additionally, the high-resolution parametric images show distinct regions of high blood flow developing during late gestation. The developed methods could be applied to assess placental vascular remodelling during the treatment of the pathologies of pregnancy.
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Affiliation(s)
- Dylan J Lawrence
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA 70118, USA
| | - Kristie Huda
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA 70118, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA 70118, USA
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White SE, Conway CK, Clark GL, Lawrence DJ, Bayer CL, Miller KS. Biaxial Basal Tone and Passive Testing of the Murine Reproductive System Using a Pressure Myograph. J Vis Exp 2019. [PMID: 31475982 DOI: 10.3791/60125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The female reproductive organs, specifically the vagina and cervix, are composed of various cellular components and a unique extracellular matrix (ECM). Smooth muscle cells exhibit a contractile function within the vaginal and cervical walls. Depending on the biochemical environment and the mechanical distension of the organ walls, the smooth muscle cells alter the contractile conditions. The contribution of the smooth muscle cells under baseline physiological conditions is classified as a basal tone. More specifically, a basal tone is the baseline partial constriction of smooth muscle cells in the absence of hormonal and neural stimulation. Furthermore, the ECM provides structural support for the organ walls and functions as a reservoir for biochemical cues. These biochemical cues are vital to various organ functions, such as inciting growth and maintaining homeostasis. The ECM of each organ is composed primarily of collagen fibers (mostly collagen types I, III, and V), elastic fibers, and glycosaminoglycans/proteoglycans. The composition and organization of the ECM dictate the mechanical properties of each organ. A change in ECM composition may lead to the development of reproductive pathologies, such as pelvic organ prolapse or premature cervical remodeling. Furthermore, changes in ECM microstructure and stiffness may alter smooth muscle cell activity and phenotype, thus resulting in the loss of the contractile force. In this work, the reported protocols are used to assess the basal tone and passive mechanical properties of the nonpregnant murine vagina and cervix at 4-6 months of age in estrus. The organs were mounted in a commercially available pressure myograph and both pressure-diameter and force-length tests were performed. Sample data and data analysis techniques for the mechanical characterization of the reproductive organs are included. Such information may be useful for constructing mathematical models and rationally designing therapeutic interventions for women's health pathologies.
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Clark GL, Pokutta-Paskaleva AP, Lawrence DJ, Lindsey SH, Desrosiers L, Knoepp LR, Bayer CL, Gleason RL, Miller KS. Smooth muscle regional contribution to vaginal wall function. Interface Focus 2019; 9:20190025. [PMID: 31263538 PMCID: PMC6597518 DOI: 10.1098/rsfs.2019.0025] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2019] [Indexed: 12/16/2022] Open
Abstract
Pelvic organ prolapse is characterized as the descent of the pelvic organs into the vaginal canal. In the USA, there is a 12% lifetime risk for requiring surgical intervention. Although vaginal childbirth is a well-established risk factor for prolapse, the underlying mechanisms are not fully understood. Decreased smooth muscle organization, composition and maximum muscle tone are characteristics of prolapsed vaginal tissue. Maximum muscle tone of the vaginal wall was previously investigated in the circumferential or axial direction under uniaxial loading; however, the vaginal wall is subjected to multiaxial loads. Further, the contribution of vaginal smooth muscle basal (resting) tone to mechanical function remains undetermined. The objectives of this study were to determine the contribution of smooth muscle basal and maximum tone to the regional biaxial mechanical behaviour of the murine vagina. Vaginal tissue from C57BL/6 mice was subjected to extension-inflation protocols (n = 10) with and without basal smooth muscle tone. Maximum tone was induced with KCl under various circumferential (n = 5) and axial (n = 5) loading conditions. The microstructure was visualized with multiphoton microscopy (n = 1), multiaxial histology (n = 4) and multiaxial immunohistochemistry (n = 4). Smooth muscle basal tone decreased material stiffness and increased anisotropy. In addition, maximum vaginal tone was decreased with increasing intraluminal pressures. This study demonstrated that vaginal muscle tone contributed to the biaxial mechanical response of murine vaginal tissue. This may be important in further elucidating the underlying mechanisms of prolapse, in order to improve current preventative and treatment strategies.
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Affiliation(s)
- Gabrielle L. Clark
- Department of Biomedical Engineering, Tulane University, 6823 St Charles Avenue, New Orleans, LA 70118, USA
| | - Anastassia P. Pokutta-Paskaleva
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 801 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Dylan J. Lawrence
- Department of Biomedical Engineering, Tulane University, 6823 St Charles Avenue, New Orleans, LA 70118, USA
| | - Sarah H. Lindsey
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA
| | - Laurephile Desrosiers
- Department of Female Pelvic Medicine and Reconstructive Surgery, University of Queensland Ochsner Clinical School, 1514 Jefferson Highway, New Orleans, LA 70121, USA
| | - Leise R. Knoepp
- Department of Female Pelvic Medicine and Reconstructive Surgery, University of Queensland Ochsner Clinical School, 1514 Jefferson Highway, New Orleans, LA 70121, USA
| | - Carolyn L. Bayer
- Department of Biomedical Engineering, Tulane University, 6823 St Charles Avenue, New Orleans, LA 70118, USA
| | - Rudolph L. Gleason
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 801 Ferst Drive NW, Atlanta, GA 30332, USA
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Kristin S. Miller
- Department of Biomedical Engineering, Tulane University, 6823 St Charles Avenue, New Orleans, LA 70118, USA
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Lawrence DJ, Escott ME, Myers L, Intapad S, Lindsey SH, Bayer CL. Spectral photoacoustic imaging to estimate in vivo placental oxygenation during preeclampsia. Sci Rep 2019; 9:558. [PMID: 30679723 PMCID: PMC6345947 DOI: 10.1038/s41598-018-37310-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
Preeclampsia is a pregnancy-related hypertensive disorder accounting for 14% of global maternal deaths annually. Preeclampsia - maternal hypertension and proteinuria - is promoted by placental ischemia resulting from reduced uteroplacental perfusion. Here, we assess longitudinal changes in placental oxygenation during preeclampsia using spectral photoacoustic imaging. Spectral photoacoustic images were acquired of the placenta of normal pregnant (NP) and preeclamptic reduced uterine perfusion pressure (RUPP) Sprague Dawley rats on gestational days (GD) 14, 16, and 18, corresponding to mid- to late gestation (n = 10 per cohort). Two days after implementation of the RUPP surgical model, placental oxygen saturation decreased 12% in comparison with NP. Proteinuria was determined from a 24-hour urine collection prior to imaging on GD18. Blood pressure measurements were obtained on GD18 after imaging. Placental hypoxia in the RUPP was confirmed with histological staining for hypoxia-inducible factor (HIF)-1α, a cellular transcription regulator which responds to local oxygen levels. Using in vivo, longitudinal imaging methods we determined that the placenta in the reduced uterine perfusion pressure rat model of preeclampsia is hypoxic, and that this hypoxia is maintained through late gestation. Future work will utilize these methods to assess the impact of novel therapeutics on placental ischemia and the progression of preeclampsia.
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Affiliation(s)
- Dylan J Lawrence
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA
| | - Megan E Escott
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA
| | - Leann Myers
- School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St #2400, New Orleans, LA, 70112, USA
| | - Suttira Intapad
- School of Medicine, Tulane University, 1430 Tulane Ave, New Orleans, LA, 70112, USA
| | - Sarah H Lindsey
- School of Medicine, Tulane University, 1430 Tulane Ave, New Orleans, LA, 70112, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA, 70118, USA.
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Ogola BO, Abshire CM, Clark GL, Lawrence DJ, Zimmerman MA, Bayer CL, Miller KS, Lindsey SH. Abstract 113: Female Protection From Arterial Stiffness Diminishes With G Protein-Coupled Estrogen Receptor Deletion or Angiotensin II Hypertension. Hypertension 2018. [DOI: 10.1161/hyp.72.suppl_1.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Arterial stiffness independently predicts cardiovascular mortality, coronary events, and stroke in hypertensive subjects and is exacerbated in women following menopause. Previously, our laboratory indicated that G protein-coupled estrogen receptor (GPER) plays a protective role in the vasculature. Therefore, the current study assessed the impact of sex and GPER on arterial stiffening in control and hypertensive conditions. We hypothesized that genetic deletion of GPER attenuates sex differences in arterial stiffness. Male and female wildtype (wt) and global GPER knockout (ko) mice (n=46) were used between 16-21 weeks of age. Angiotensin II (Ang II) infusion (700 ng/kg/day for two weeks) was used to induce hypertension, and systolic blood pressure (SBP) was measured using tail cuff plethysmography. Local pulse wave velocity (PWV) within the carotid artery was obtained via high frequency ultrasound in both color Doppler and M-mode. Statistical analysis was performed using two-way ANOVA with Sidak’s multiple comparisons test. Baseline SBP was significantly lower in females (P=0.035) but was not impacted by genotype (P=0.78). Baseline PWV was significantly higher in male versus female wt mice (1.29 vs. 0.804 m/s, P=0.003) but was not different in ko mice (1.25 vs. 1.04 m/s, P=0.22). Ang II infusion significantly increased SBP (P<0.001) and PWV (P<0.001) in all groups, removing any impact of sex or genotype. In addition, significant correlations were found between Doppler and M-mode methods for obtaining carotid PWV (r=0.67, P<0.001) and between PWV and
ex vivo
carotid wall thickness (r=0.70, P=0.004). In contrast, SBP did not correlate with PWV (P=0.77) or carotid wall thickness (P=0.68). In conclusion, we found that GPER deletion did not impact blood pressure either in normotensive or hypertensive conditions. While arteries from female wt mice were less stiff at baseline, genetic deletion of GPER or Ang II infusion removed this protection independent of blood pressure. Moreover, we found that local carotid PWV provides information on vascular status that could not be obtained via blood pressure. This data indicates that GPER plays an important role in female vascular physiology that is absent in pathological conditions.
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Suarez-Martinez AD, Bierschenk S, Huang K, Kaplan D, Bayer CL, Meadows SM, Sperandio M, Murfee WL. A Novel ex vivo Mouse Mesometrium Culture Model for Investigating Angiogenesis in Microvascular Networks. J Vasc Res 2018; 55:125-135. [PMID: 29779031 DOI: 10.1159/000489102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 02/16/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The development of models that incorporate intact microvascular networks enables the investigation of multicellular dynamics during angiogenesis. Our laboratory introduced the rat mesentery culture model as such a tool, which would be enhanced with mouse tissue. Since mouse mesentery is avascular, an alternative is mouse mesometrium, the connective tissue of uterine horns. The study's objective was to demonstrate that mouse mesometrium contains microvascular networks that can be cultured to investigate multicellular dynamics during angiogenesis. METHODS Harvested mesometrium tissues from C57Bl/6 female mice were cultured in media with serum for up to 7 days. PECAM, NG2, αSMA, and LYVE-1 labeling identified endothelial cells, pericytes, smooth muscle cells, and lymphatic endothelial cells, respectively. RESULTS These cells comprised microvascular networks with arterioles, venules, and capillaries. Compared to day 0, capillary sprouts per vascular length were increased by 3 and 5 days in culture (day 0, 0.08 ± 0.01; day 3, 3.19 ± 0.78; day 5, 2.49 ± 0.05 sprouts/mm; p < 0.05). Time-lapse imaging of cultured tissues from FlkEGFP mice showcases the use of the model for lineage studies. The impact is supported by the identification of endothelial cell jumping from one sprout to another. CONCLUSION These results introduce a novel culture model for investigating multicellular dynamics during angiogenesis in real-time ex vivo microvascular networks.
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Affiliation(s)
- Ariana D Suarez-Martinez
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA.,Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
| | - Susanne Bierschenk
- Walter-Brendel-Centre of Experimental Medicine, Klinikum der Universität München, Ludwig-Maximilians-Universität, Munich, Germany
| | - Katie Huang
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Dana Kaplan
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
| | - Carolyn L Bayer
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
| | - Stryder M Meadows
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA
| | - Markus Sperandio
- Walter-Brendel-Centre of Experimental Medicine, Klinikum der Universität München, Ludwig-Maximilians-Universität, Munich, Germany
| | - Walter L Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA.,Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
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Bayer CL, Wlodarczyk BJ, Finnell RH, Emelianov SY. Ultrasound-guided spectral photoacoustic imaging of hemoglobin oxygenation during development. Biomed Opt Express 2017; 8:757-763. [PMID: 28270982 PMCID: PMC5330552 DOI: 10.1364/boe.8.000757] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/19/2016] [Accepted: 12/23/2016] [Indexed: 05/06/2023]
Abstract
Few technologies are capable of imaging in vivo function during development. In this study, we have implemented spectral photoacoustic imaging to estimate tissue oxygenation longitudinally in pregnant mice. We used the spectral photoacoustic signal to estimate hemoglobin oxygen saturation within intact, in vivo mouse concepti from developmental day (E) 8.5 to E16.5-a first step towards functional imaging of the maternal-fetal environment. Future work will apply these methods to compare longitudinal functional changes during normal vs abnormal development of embryos, fetuses, and placentas.
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Affiliation(s)
- Carolyn L. Bayer
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Currently with the Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA 70118, USA
| | - Bogdan J. Wlodarczyk
- Dell Pediatric Research Institute, Department of Nutritional Sciences, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA
| | - Richard H. Finnell
- Dell Pediatric Research Institute, Department of Nutritional Sciences, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA
| | - Stanislav Y. Emelianov
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Currently with the School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, Atlanta, GA 30332, USA
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Bayer CL, Kelvekar J, Emelianov SY. Influence of nanosecond pulsed laser irradiance on the viability of nanoparticle-loaded cells: implications for safety of contrast-enhanced photoacoustic imaging. Nanotechnology 2013; 24:465101. [PMID: 24150862 PMCID: PMC3916331 DOI: 10.1088/0957-4484/24/46/465101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Photoacoustic imaging, a promising new diagnostic medical imaging modality, can provide high contrast images of molecular features by introducing highly-absorbing plasmonic nanoparticles. Currently, it is uncertain whether the absorption of low fluence pulsed light by plasmonic nanoparticles could lead to cellular damage. In our studies we have shown that low fluence pulsed laser excitation of accumulated nanoparticles at low concentration does not impact cell growth and viability, while we identify thresholds at which higher nanoparticle concentrations and fluences produce clear evidence of cell death. The results provide insights for improved design of photoacoustic contrast agents and for applications in combined imaging and therapy.
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Affiliation(s)
- Carolyn L Bayer
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
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Abstract
The metastasis of cancer is a multistage process involving complex biological interactions and difficult to predict outcomes. Accurate assessment of the extent of metastasis is critical for clinical practice; unfortunately, medical imaging methods capable of identifying the early stages of invasion and metastasis are lacking. Photoacoustic imaging is capable of providing noninvasive, real-time imaging of significant anatomical and physiological changes. indicating the progression of cancer invasion and metastasis. Preclinically, photoacoustic methods have been used to image lymphatic anatomy, including the sentinel lymph nodes, to identify circulating tumor cells within vasculature and to detect micrometastases. Progress has begun toward the development of clinically applicable photoacoustic imaging systems to assist with the determination of cancer stage and likelihood of metastatic invasion.
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Affiliation(s)
- Carolyn L Bayer
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA.
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Bayer CL, Nam SY, Chen YS, Emelianov SY. Photoacoustic signal amplification through plasmonic nanoparticle aggregation. J Biomed Opt 2013; 18:16001. [PMID: 23288414 PMCID: PMC3536717 DOI: 10.1117/1.jbo.18.1.016001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/15/2012] [Accepted: 11/27/2012] [Indexed: 05/20/2023]
Abstract
Photoacoustic imaging, using targeted plasmonic metallic nanoparticles, is a promising noninvasive molecular imaging method. Analysis of the photoacoustic signal generated by plasmonic metallic nanoparticles is complex because of the dependence upon physical properties of both the nanoparticle and the surrounding environment. We studied the effect of the aggregation of gold nanoparticles on the photoacoustic signal amplitude. We found that the photoacoustic signal from aggregated silica-coated gold nanoparticles is greatly enhanced in comparison to disperse silica-coated gold nanoparticles. Because cellular uptake and endocytosis of nanoparticles results in their aggregation, these results have important implications for the application of plasmonic metallic nanoparticles towards quantitative molecular imaging.
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Affiliation(s)
- Carolyn L. Bayer
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, Austin, Texas 78712
| | - Seung Yun Nam
- The University of Texas at Austin, Department of Electrical Engineering, 1 University Station, Austin, Texas 78712
| | - Yun-Sheng Chen
- The University of Texas at Austin, Department of Electrical Engineering, 1 University Station, Austin, Texas 78712
| | - Stanislav Y. Emelianov
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, Austin, Texas 78712
- The University of Texas at Austin, Department of Electrical Engineering, 1 University Station, Austin, Texas 78712
- Address all correspondence to: Stanislav Y. Emelianov, The University of Texas at Austin, Department of Biomedical and Electrical Engineering, 1 University Station, Austin, Texas 78712. Tel: (512) 417-1733; Fax: (512) 471-0616; E-mail:
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21
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Bayer CL, Nam SY, Chen YS, Emelianov SY. Photoacoustic signal amplification through plasmonic nanoparticle aggregation. J Biomed Opt 2013. [PMID: 25535976 DOI: 10.1117/1.jbo] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Photoacoustic imaging, using targeted plasmonic metallic nanoparticles, is a promising noninvasive molecular imaging method. Analysis of the photoacoustic signal generated by plasmonic metallic nanoparticles is complex because of the dependence upon physical properties of both the nanoparticle and the surrounding environment. We studied the effect of the aggregation of gold nanoparticles on the photoacoustic signal amplitude. We found that the photoacoustic signal from aggregated silica-coated gold nanoparticles is greatly enhanced in comparison to disperse silica-coated gold nanoparticles. Because cellular uptake and endocytosis of nanoparticles results in their aggregation, these results have important implications for the application of plasmonic metallic nanoparticles towards quantitative molecular imaging.
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Affiliation(s)
- Carolyn L Bayer
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, Austin, Texas 78712, USA
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Bayer CL, Herrero ÉP, Peppas NA. Alginate Films as Macromolecular Imprinted Matrices. Journal of Biomaterials Science, Polymer Edition 2012; 22:1523-34. [DOI: 10.1163/092050610x514115] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Carolyn L. Bayer
- a Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, Department of Biomedical Engineering, 1 University Station, C0400, The University of Texas at Austin, Austin, TX 78712-0231, USA
| | - Édgar Pérez Herrero
- b Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, Department of Chemical Engineering, 1 University Station, C0400, The University of Texas at Austin, Austin, TX 78712-0231, USA
| | - Nicholas A. Peppas
- c Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, Department of Biomedical Engineering, 1 University Station, C0400, The University of Texas at Austin, Austin, TX 78712-0231, USA; Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, Department of Chemical Engineering, 1 University Station, C0400, The University of Texas at Austin, Austin, TX 78712-0231, USA
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Bayer CL, Trenchard IJ, Peppas NA. Analyzing Polyaniline-poly(2-acrylamido-2-methylpropane sulfonic acid) Biocompatibility with 3T3 Fibroblasts. Journal of Biomaterials Science, Polymer Edition 2012; 21:623-34. [DOI: 10.1163/156856209x434647] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Carolyn L. Bayer
- a Department of Biomedical Engineering, Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, 1 University Station, C-0400, The University of Texas at Austin, Austin, TX 78712-0231, USA
| | - Isis J. Trenchard
- b Department of Biomedical Engineering, Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, 1 University Station, C-0400, The University of Texas at Austin, Austin, TX 78712-0231, USA
| | - Nicholas A. Peppas
- c Department of Biomedical Engineering, Department of Chemical Engineering, Department of Pharmaceutics, Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, 1 University Station, C-0400, The University of Texas at Austin, Austin, TX 78712-0231, USA;,
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Bayer CL, Chen YS, Kim S, Mallidi S, Sokolov K, Emelianov S. Multiplex photoacoustic molecular imaging using targeted silica-coated gold nanorods. Biomed Opt Express 2011; 2:1828-35. [PMID: 21750761 PMCID: PMC3130570 DOI: 10.1364/boe.2.001828] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 05/27/2011] [Accepted: 05/31/2011] [Indexed: 05/18/2023]
Abstract
The establishment of multiplex photoacoustic molecular imaging to characterize heterogeneous tissues requires the use of a tunable, thermally stable contrast agent targeted to specific cell types. We have developed a multiplex photoacoustic imaging technique which uses targeted silica-coated gold nanorods to distinguish cell inclusions in vitro. This paper describes the use of tunable targeted silica-coated gold nanorods (SiO(2)-AuNRs) as contrast agents for photoacoustic molecular imaging. SiO(2)-AuNRs with peak absorption wavelengths of 780 nm and 830 nm were targeted to cells expressing different cell receptors. Cells were incubated with the targeted SiO(2)-AuNRs, incorporated in a tissue phantom, and imaged using multiwavelength photoacoustic imaging. We used photoacoustic imaging and statistical correlation analysis to distinguish between the unique cell inclusions within the tissue phantom.
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Affiliation(s)
- Carolyn L. Bayer
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
| | - Yun-Sheng Chen
- Department of Electrical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
| | - Seungsoo Kim
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
| | - Srivalleesha Mallidi
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Currently with the Wellman Center for Photomedicine, Harvard Medical School, Boston, MA 02114, USA
| | - Konstantin Sokolov
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030 USA
| | - Stanislav Emelianov
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Department of Electrical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030 USA
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Su JL, Wang B, Wilson KE, Bayer CL, Chen YS, Kim S, Homan KA, Emelianov SY. Advances in Clinical and Biomedical Applications of Photoacoustic Imaging. Expert Opin Med Diagn 2010; 4:497-510. [PMID: 21344060 PMCID: PMC3041963 DOI: 10.1517/17530059.2010.529127] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD: Photoacoustic imaging is an imaging modality that derives image contrast from the optical absorption coefficient of the tissue being imaged. The imaging technique is able to differentiate between healthy and diseased tissue with either deeper penetration or higher resolution than other functional imaging modalities currently available. From a clinical standpoint, photoacoustic imaging has demonstrated safety and effectiveness in diagnosing diseased tissue regions using either endogenous tissue contrast or exogenous contrast agents. Furthermore, the potential of photoacoustic imaging has been demonstrated in various therapeutic interventions ranging from drug delivery and release to image-guided therapy and monitoring. AREAS COVERED IN THIS REVIEW: This article reviews the current state of photoacoustic imaging in biomedicine from a technological perspective, highlights various biomedical and clinical applications of photoacoustic imaging, and gives insights on future directions. WHAT THE READER WILL GAIN: Readers will learn about the various applications of photoacoustic imaging, as well as the various contrast agents that can be used to assist photoacoustic imaging. This review will highlight both pre-clinical and clinical uses for photoacoustic imaging, as well as discuss some of the challenges that must be addressed to move photoacoustic imaging into the clinical realm. TAKE HOME MESSAGE: Photoacoustic imaging offers unique advantages over existing imaging modalities. The imaging field is broad with many exciting applications for detecting and diagnosing diseased tissue or processes. Photoacoustics is also used in therapeutic applications to identify and characterize the pathology and then to monitor the treatment. Although the technology is still in its infancy, much work has been done in the pre-clinical arena, and photoacoustic imaging is fast approaching the clinical setting.
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Affiliation(s)
- Jimmy L. Su
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Bo Wang
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Katheryne E. Wilson
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Carolyn L. Bayer
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Yun-Sheng Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Seungsoo Kim
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Kimberly A. Homan
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
| | - Stanislav Y. Emelianov
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712 USA
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Bayer CL, Konuk AA, Peppas NA. Development of a protein sensing device utilizing interactions between polyaniline and a polymer acid dopant. Biomed Microdevices 2010; 12:435-42. [PMID: 20174872 DOI: 10.1007/s10544-010-9400-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human disease processes are often characterized by a deviation from the normal physiological concentration of critical biomarkers. The detection of disease biomarkers requires the development of novel sensing methods which are sensitive, specific, efficient and low-cost. To address this need, the ability of a device, which incorporates a film of polymer acid doped polyaniline, to respond to proteins at physiological pH and ionic strength was assessed. The conductive polymer was found to respond by changing conductivity in the presence of biomolecules, demonstrating a direct chemical to electronic transduction method. In future work, specificity can be incorporated into the system by integrating the conductive polymer with a protein selective film. The demonstration of a conductive polymer which is responsive to proteins at physiological conditions is a step towards the integration of these materials into implantable sensing systems.
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Affiliation(s)
- Carolyn L Bayer
- Department of Biomedical Engineering, Center on Biomaterials, Drug Delivery, Bionanotechnology and Molecular Recognition, The University of Texas at Austin, 1 University Station, C0400, Austin, TX 78712-0231, USA
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