1
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Yakimov B, Rovnyagina N, Hasan A, Zhang J, Wang H, Fadeev V, Urusova L, Khoroshilov E, Sharkov A, Mokrysheva N, Shirshin E. Fluorescence saturation imaging microscopy: molecular fingerprinting with a standard confocal microscope. BIOMEDICAL OPTICS EXPRESS 2024; 15:3755-3769. [PMID: 38867799 PMCID: PMC11166444 DOI: 10.1364/boe.512188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 06/14/2024]
Abstract
Molecular specificity in fluorescence imaging of cells and tissues can be increased by measuring parameters other than intensity. For instance, fluorescence lifetime imaging became a widespread modality for biomedical optics. Previously, we suggested using the fluorescence saturation effect at pulsed laser excitation to map the absorption cross-section as an additional molecular contrast in two-photon microscopy [Opt. Lett.47(17), 4455 (2022).10.1364/OL.465605]. Here, it is shown that, somewhat counterintuitive, fluorescence saturation can be observed under cw excitation in a standard confocal microscopy setup. Mapping the fluorescence saturation parameter allows obtaining additional information about the fluorophores in the system, as demonstrated by the example of peptide hydrogel, stained cells and unstained thyroid gland. The suggested technique does not require additional equipment and can be implemented on confocal systems as is.
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Affiliation(s)
- Boris Yakimov
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University, Trubetskaya 8, Moscow 119048, Russia
- Vorohobov’s City Clinical Hospital №67 MHD Moscow, 2/44 Salam Adil St., Moscow 123423, Russia
| | - Natalia Rovnyagina
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University, Trubetskaya 8, Moscow 119048, Russia
| | - Afraa Hasan
- HSE University, Faculty of Physics, Myasnitskaya St., 20, Moscow 101100, Russia
| | - Juntao Zhang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 4300023, China
| | - Haibo Wang
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, Hubei 4300023, China
| | - Victor Fadeev
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, 119991 Moscow, Russia
| | - Liliya Urusova
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
| | - Evgeny Khoroshilov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991 Moscow, Russia
| | - Andrey Sharkov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991 Moscow, Russia
| | - Nataliya Mokrysheva
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
| | - Evgeny Shirshin
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, 119991 Moscow, Russia
- Endocrinology Research Center, Dmitriya Ulianova Street, 11, 117036 Moscow, Russia
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2
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Steitz M, Zouhair S, Khan MB, Breitenstein-Attach A, Fritsch K, Tuladhar SR, Wulsten D, Wolkers WF, Sun X, Hao Y, Emeis J, Lange HE, Berger F, Schmitt B. A Glutaraldehyde-Free Crosslinking Method for the Treatment of Collagen-Based Biomaterials for Clinical Application. Bioengineering (Basel) 2023; 10:1247. [PMID: 38002371 PMCID: PMC10669889 DOI: 10.3390/bioengineering10111247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 11/26/2023] Open
Abstract
Biological bioprostheses such as grafts, patches, and heart valves are often derived from biological tissue like the pericardium. These bioprostheses can be of xenogenic, allogeneic, or autologous origin. Irrespective of their origin, all types are pre-treated via crosslinking to render the tissue non-antigenic and mechanically strong or to minimize degradation. The most widely used crosslinking agent is glutaraldehyde. However, glutaraldehyde-treated tissue is prone to calcification, inflammatory degradation, and mechanical injury, and it is incapable of matrix regeneration, leading to structural degeneration over time. In this work, we are investigating an alternative crosslinking method for an intraoperative application. The treated tissue's crosslinking degree was evaluated by differential scanning calorimetry. To confirm the findings, a collagenase assay was conducted. Uniaxial tensile testing was used to assess the tissue's mechanical properties. To support the findings, the treated tissue was visualized using two-photon microscopy. Additionally, fourier transform infrared spectroscopy was performed to study the overall protein secondary structure. Finally, a crosslinking procedure was identified for intraoperative processing. The samples showed a significant increase in thermal and enzymatic stability after treatment compared to the control, with a difference of up to 22.2 °C and 100%, respectively. Also, the tissue showed similar biomechanics to glutaraldehyde-treated tissue, showing greater extensibility, a higher failure strain, and a lower ultimate tensile strength than the control. The significant difference in the structure band ratio after treatment is proof of the introduction of additional crosslinks compared to the untreated control with regard to differences in the amide-I region. The microscopic images support these findings, showing an alteration of the fiber orientation after treatment. For collagen-based biomaterials, such as pericardial tissue, the novel phenolic crosslinking agent proved to be an equivalent alternative to glutaraldehyde regarding tissue characteristics. Although long-term studies must be performed to investigate superiority in terms of longevity and calcification, our novel crosslinking agent can be applied in concentrations of 1.5% or 2.0% for the treatment of biomaterials.
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Affiliation(s)
- Marvin Steitz
- Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Berlin (Charité), D-13353 Berlin, Germany
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
- German Centre for Cardiovascular Research, D-10785 Berlin, Germany
| | - Sabra Zouhair
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
| | - Mahamuda Badhon Khan
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
| | - Alexander Breitenstein-Attach
- Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Berlin (Charité), D-13353 Berlin, Germany
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
- German Centre for Cardiovascular Research, D-10785 Berlin, Germany
| | - Katharina Fritsch
- Department Dynamics and Transport in Quantum Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, D-14109 Berlin, Germany
| | - Sugat Ratna Tuladhar
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development, University of Veterinary Medicine Hanover, D-30625 Hannover, Germany
| | - Dag Wulsten
- Julius Wolff Institute—Center for Musculoskeletal Biomechanics and Regeneration, D-13353 Berlin, Germany
| | - Willem-Frederik Wolkers
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development, University of Veterinary Medicine Hanover, D-30625 Hannover, Germany
| | - Xiaolin Sun
- Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Berlin (Charité), D-13353 Berlin, Germany
- German Centre for Cardiovascular Research, D-10785 Berlin, Germany
| | - Yimeng Hao
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
| | - Jasper Emeis
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
| | - Hans-E. Lange
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
| | - Felix Berger
- Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Berlin (Charité), D-13353 Berlin, Germany
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
- German Centre for Cardiovascular Research, D-10785 Berlin, Germany
| | - Boris Schmitt
- Department of Pediatric Cardiology and Congenital Heart Disease, German Heart Center Berlin (Charité), D-13353 Berlin, Germany
- Department of Pediatric Cardiology and Congenital Heart Disease, Charité University Medicine Berlin, D-13353 Berlin, Germany
- German Centre for Cardiovascular Research, D-10785 Berlin, Germany
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3
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Diamantides N, Slyker L, Martin S, Rodriguez MR, Bonassar LJ. Pre-glycation impairs gelation of high concentration collagen solutions. J Biomed Mater Res A 2022; 110:1953-1963. [PMID: 36183358 PMCID: PMC9648490 DOI: 10.1002/jbm.a.37431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/30/2022] [Accepted: 07/21/2022] [Indexed: 09/29/2023]
Abstract
There remains a need for stiffer collagen hydrogels for tissue engineering and disease modeling applications. Pre-glycation, or glycation of collagen in solution prior to gelation, has been shown to increase the mechanics of collagen hydrogels while maintaining high viability of encapsulated cells. The stiffness of glycated collagen gels can be increased by increasing the collagen concentration, sugar concentration, and glycation time. However, previous studies on pre-glycation of collagen have used low collagen concentrations and/or low sugar concentrations and have not investigated the effect of glycation time. Therefore, the objective of this study was to determine the effects of pre-glycation with high sugar concentrations (up to 500 mM) and extended glycation times (up to 21 days) on high concentration collagen (8 mg/ml). The addition of sugar to the collagen and the formation of advanced glycation end products (AGEs) were quantified. The ability to gel successfully and rheological properties were determined and correlated with biochemical characterizations. Successful collagen gelation and rheological properties of pre-glycated collagen were found to be strongly dependent on the ratio of added sugars to added AGEs with high ratios impairing gelation and low ratios resulting in optimal storage moduli. There is likely a competing effect during pre-glycation of the formation of AGEs resulting in crosslinking of collagen and the formation of Amadori intermediates acting to increase collagen solubility. Overall, this study shows that collagen glycation can be optimized by increasing the formation of AGEs while maintaining a low ratio of added sugar to added AGEs.
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Affiliation(s)
| | - Leigh Slyker
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Sara Martin
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY
| | | | - Lawrence J. Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY
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4
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Clark AG, Maitra A, Jacques C, Bergert M, Pérez-González C, Simon A, Lederer L, Diz-Muñoz A, Trepat X, Voituriez R, Vignjevic DM. Self-generated gradients steer collective migration on viscoelastic collagen networks. NATURE MATERIALS 2022; 21:1200-1210. [PMID: 35637338 DOI: 10.1038/s41563-022-01259-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
Growing evidence suggests that the physical properties of the cellular microenvironment influence cell migration. However, it is not currently understood how active physical remodelling by cells affects migration dynamics. Here we report that cell clusters seeded on deformable collagen-I networks display persistent collective migration despite not showing any apparent intrinsic polarity. Clusters generate transient gradients in collagen density and alignment due to viscoelastic relaxation of the collagen networks. Combining theory and experiments, we show that crosslinking collagen networks or reducing cell cluster size results in reduced network deformation, shorter viscoelastic relaxation time and smaller gradients, leading to lower migration persistence. Traction force and Brillouin microscopy reveal asymmetries in force distributions and collagen stiffness during migration, providing evidence of mechanical cross-talk between cells and their substrate during migration. This physical model provides a mechanism for self-generated directional migration on viscoelastic substrates in the absence of internal biochemical polarity cues.
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Affiliation(s)
- Andrew G Clark
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, CNRS, Paris, France.
- Institute of Cell Biology and Immunology, Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany.
- Center for Personalized Medicine, University of Tübingen, Tübingen, Germany.
| | - Ananyo Maitra
- Laboratoire Jean Perrin, Sorbonne Université and CNRS, Paris, France.
- Laboratoire de Physique Théorique et Modélisation, CNRS, CY Cergy Paris Université, Cergy-Pontoise Cedex, France.
| | - Cécile Jacques
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, CNRS, Paris, France
| | - Martin Bergert
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Carlos Pérez-González
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, CNRS, Paris, France
| | - Anthony Simon
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, CNRS, Paris, France
| | - Luc Lederer
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, CNRS, Paris, France
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia, The Barcelona Institute for Science and Technology (BIST), Barcelona, Spain
- Facultat de Medicina, University of Barcelona, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Barcelona, Spain
| | - Raphaël Voituriez
- Laboratoire de Physique Théorique et Modélisation, CNRS, CY Cergy Paris Université, Cergy-Pontoise Cedex, France
- Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université and CNRS, Paris, France
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5
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Slyker L, Diamantides N, Kim J, Bonassar LJ. Mechanical performance of collagen gels is dependent on purity, α1/α2 ratio, and telopeptides. J Biomed Mater Res A 2022; 110:11-20. [PMID: 34236763 PMCID: PMC9271356 DOI: 10.1002/jbm.a.37261] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 05/27/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023]
Abstract
This article describes the compositional, mechanical, and structural differences between collagen gels fabricated from different sources and processing methods. Despite extensive use of collagen in the manufacturing of biomaterials and implants, there is little information as to the variation in properties based on collagen source or processing methods. As such, differences in purity and composition may affect gel structure and mechanical performance. Using mass spectrometry, we assessed protein composition of collagen from seven different sources. The mechanics and gelation kinetics of each gel were assessed through oscillatory shear rheology. Scanning electron microscopy enabled visualization of distinct differences in fiber morphology. Mechanics and gelation kinetics differed with source and processing method and were found to correlate with differences in composition. Gels fabricated from telopeptide-containing collagens had higher storage modulus (144 vs. 54 Pa) and faster gelation (251 vs. 734 s) compared to atelocollagens, despite having lower purity (93.4 vs. 99.8%). For telopeptide-containing collagens, as collagen purity increased, storage modulus increased and fiber diameter decreased. As α1/α2 chain ratio increased, fiber diameter increased and gelation slowed. As such, this study provides an examination of the effects of collagen processing on key quality attributes for use of collagen gels in biomedical contexts.
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Affiliation(s)
- Leigh Slyker
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
| | | | - Jongkil Kim
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Lawrence J. Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY,Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY
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6
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Paganelli A, Tarentini E, Benassi L, Scelfo D, Pisciotta A, Rossi E, Magnoni C. Use of confocal microscopy imaging for in vitro assessment of adipose-derived mesenchymal stromal cells seeding on acellular dermal matrices: 3D reconstruction based on collagen autofluorescence. Skin Res Technol 2021; 28:133-141. [PMID: 34555218 PMCID: PMC9292443 DOI: 10.1111/srt.13103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/21/2021] [Indexed: 12/16/2022]
Abstract
Background Both mesenchymal stromal cells (MSCs) and acellular dermal matrices (ADMs) represent fascinating therapeutic tools in the wound healing scenario. Strategies aimed at combining these two treatment modalities are currently under investigation. Moreover, scarcity of quantitative, nondestructive techniques for quality assessment of engineered tissues poses great limitations in regenerative medicine and collagen autofluorescence‐based imaging techniques are acquiring great importance in this setting. Objective Our goals were to assess the in vitro interactions between ADSCs and ADMs and to analyze extracellular‐matrix production. Methods Adipose‐derived MSCs (ADSC) were plated on 8‐mm punch biopsies of a commercially available ADM (Integra®). Conventional histology with hematoxylin‐eosin staining, environmental scanning electron microscopy, and confocal‐laser scanning microscopy were used to obtain imaging of ADSC‐seeded ADMs. Collagen production by ADSCs was quantified by mean fluorescence intensity (MFI), expressed in terms of positive pixels/field, obtained through ImageJ software processing of three‐dimensional projections from confocal scanning images. Control conditions included: fibroblast‐seeded ADM, ADSC‐ and fibroblast‐induced scaffolds, and Integra® alone. Results ADSCs were efficiently seeded on Integra® and were perfectly incorporated in the pores of the scaffold. Collagen production was revealed to be significantly higher when ADSCs were seeded on ADM rather than in all other control conditions. Collagen autofluorescence was efficiently used as a surrogate marker of ECM production. Conclusions Combined therapies based on MSCs and collagenic ADMs are promising therapeutic options for chronic wounds. Not only ADSCs can be efficiently seeded on ADMs, but ADMs also seem to potentiate their regenerative properties, as highlightable from fluorescence confocal imaging.
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Affiliation(s)
- Alessia Paganelli
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy.,PhD Program in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Elisabetta Tarentini
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Luisa Benassi
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Daniel Scelfo
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Alessandra Pisciotta
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Elena Rossi
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
| | - Cristina Magnoni
- Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, Division of Dermatology, University of Modena and Reggio Emilia, Modena and Reggio Emilia, Italy
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7
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Hu LY, Mileti CJ, Loomis T, Brashear SE, Ahmad S, Chellakudam RR, Wohlgemuth RP, Gionet-Gonzales MA, Leach JK, Smith LR. Skeletal muscle progenitors are sensitive to collagen architectural features of fibril size and cross linking. Am J Physiol Cell Physiol 2021; 321:C330-C342. [PMID: 34191625 DOI: 10.1152/ajpcell.00065.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Muscle stem cells (MuSCs) are essential for the robust regenerative capacity of skeletal muscle. However, in fibrotic environments marked by abundant collagen and altered collagen organization, the regenerative capability of MuSCs is diminished. MuSCs are sensitive to their extracellular matrix environment but their response to collagen architecture is largely unknown. The present study aimed to systematically test the effect of underlying collagen structures on MuSC functions. Collagen hydrogels were engineered with varied architectures: collagen concentration, cross linking, fibril size, and fibril alignment, and the changes were validated with second harmonic generation imaging and rheology. Proliferation and differentiation responses of primary mouse MuSCs and immortal myoblasts (C2C12s) were assessed using EdU assays and immunolabeling skeletal muscle myosin expression, respectively. Changing collagen concentration and the corresponding hydrogel stiffness did not have a significant influence on MuSC proliferation or differentiation. However, MuSC differentiation on atelocollagen gels, which do not form mature pyridinoline cross links, was increased compared with the cross-linked control. In addition, MuSCs and C2C12 myoblasts showed greater differentiation on gels with smaller collagen fibrils. Proliferation rates of C2C12 myoblasts were also higher on gels with smaller collagen fibrils, whereas MuSCs did not show a significant difference. Surprisingly, collagen alignment did not have significant effects on muscle progenitor function. This study demonstrates that MuSCs are capable of sensing their underlying extracellular matrix (ECM) structures and enhancing differentiation on substrates with less collagen cross linking or smaller collagen fibrils. Thus, in fibrotic muscle, targeting cross linking and fibril size rather than collagen expression may more effectively support MuSC-based regeneration.
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Affiliation(s)
- Lin-Ya Hu
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - Cassidy J Mileti
- Biomedical Engineering Graduate Group, University of California, Davis, California
| | - Taryn Loomis
- Biomedical Engineering Graduate Group, University of California, Davis, California
| | - Sarah E Brashear
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - Sarah Ahmad
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - Rosemary R Chellakudam
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - Ross P Wohlgemuth
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | | | - J Kent Leach
- Department of Biomedical Engineering, University of California, Davis, California.,Department of Orthopaedic Surgery, University of California, Davis, California
| | - Lucas R Smith
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California.,Department of Physical Medicine and Rehabilitation, University of California, Davis, California
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8
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Bielajew BJ, Hu JC, Athanasiou KA. Collagen: quantification, biomechanics, and role of minor subtypes in cartilage. NATURE REVIEWS. MATERIALS 2020; 5:730-747. [PMID: 33996147 PMCID: PMC8114887 DOI: 10.1038/s41578-020-0213-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/28/2020] [Indexed: 05/02/2023]
Abstract
Collagen is a ubiquitous biomaterial in vertebrate animals. Although each of its 28 subtypes contributes to the functions of many different tissues in the body, most studies on collagen or collagenous tissues have focussed on only one or two subtypes. With recent developments in analytical chemistry, especially mass spectrometry, significant advances have been made toward quantifying the different collagen subtypes in various tissues; however, high-throughput and low-cost methods for collagen subtype quantification do not yet exist. In this Review, we introduce the roles of collagen subtypes and crosslinks, and describe modern assays that enable a deep understanding of tissue physiology and disease states. Using cartilage as a model tissue, we describe the roles of major and minor collagen subtypes in detail; discuss known and unknown structure-function relationships; and show how tissue engineers may harness the functional characteristics of collagen to engineer robust neotissues.
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Affiliation(s)
- Benjamin J. Bielajew
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Jerry C. Hu
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Kyriacos A. Athanasiou
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
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9
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Vazquez-Portalatin N, Alfonso-Garcia A, Liu JC, Marcu L, Panitch A. Physical, Biomechanical, and Optical Characterization of Collagen and Elastin Blend Hydrogels. Ann Biomed Eng 2020; 48:2924-2935. [PMID: 32929559 DOI: 10.1007/s10439-020-02605-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022]
Abstract
Collagen and elastin proteins are major components of the extracellular matrix of many organs. The presence of collagen and elastin networks, and their associated properties, in different tissues have led scientists to study collagen and elastin composites for use in tissue engineering. In this study, we characterized physical, biochemical, and optical properties of gels composed of collagen and elastin blends. We demonstrated that the addition of varying amounts of elastin to the constructs alters collagen fibrillogenesis, D-banding pattern length, and storage modulus. However, the addition of elastin does not affect collagen fibril diameter. We also evaluated the autofluorescence properties of the different collagen and elastin blends with fluorescence lifetime imaging (FLIm). Autofluorescence emission showed a red shift with the addition of elastin to the hydrogels. The fluorescence lifetime values of the gels increased with the addition of elastin and were strongly correlated with the storage moduli measurements. These results suggest that FLIm can be used to monitor the gels' mechanical properties nondestructively. These collagen and elastin constructs, along with the FLIm capabilities, can be used to develop and study collagen and elastin composites for tissue engineering and regenerative medicine.
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Affiliation(s)
- Nelda Vazquez-Portalatin
- Biomedical Engineering Department, University of California, Davis, 451 Health Sciences Dr, Davis, CA, 95616, USA.,Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, USA
| | - Alba Alfonso-Garcia
- Biomedical Engineering Department, University of California, Davis, 451 Health Sciences Dr, Davis, CA, 95616, USA
| | - Julie C Liu
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, USA.,Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Dr, West Lafayette, IN, 47907, USA
| | - Laura Marcu
- Biomedical Engineering Department, University of California, Davis, 451 Health Sciences Dr, Davis, CA, 95616, USA
| | - Alyssa Panitch
- Biomedical Engineering Department, University of California, Davis, 451 Health Sciences Dr, Davis, CA, 95616, USA. .,Department of Surgery, University of California, Davis, 2335 Stockton Boulevard, Sacramento, CA, 95817, USA.
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10
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Shaik TA, Alfonso-Garcia A, Richter M, Korinth F, Krafft C, Marcu L, Popp J. FLIm and Raman Spectroscopy for Investigating Biochemical Changes of Bovine Pericardium upon Genipin Cross-Linking. Molecules 2020; 25:E3857. [PMID: 32854230 PMCID: PMC7503846 DOI: 10.3390/molecules25173857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022] Open
Abstract
Biomaterials used in tissue engineering and regenerative medicine applications benefit from longitudinal monitoring in a non-destructive manner. Label-free imaging based on fluorescence lifetime imaging (FLIm) and Raman spectroscopy were used to monitor the degree of genipin (GE) cross-linking of antigen-removed bovine pericardium (ARBP) at three incubation time points (0.5, 1.0, and 2.5 h). Fluorescence lifetime decreased and the emission spectrum redshifted compared to that of uncross-linked ARBP. The Raman signature of GE-ARBP was resonance-enhanced due to the GE cross-linker that generated new Raman bands at 1165, 1326, 1350, 1380, 1402, 1470, 1506, 1535, 1574, 1630, 1728, and 1741 cm-1. These were validated through density functional theory calculations as cross-linker-specific bands. A multivariate multiple regression model was developed to enhance the biochemical specificity of FLIm parameters fluorescence intensity ratio (R2 = 0.92) and lifetime (R2 = 0.94)) with Raman spectral results. FLIm and Raman spectroscopy detected biochemical changes occurring in the collagenous tissue during the cross-linking process that were characterized by the formation of a blue pigment which affected the tissue fluorescence and scattering properties. In conclusion, FLIm parameters and Raman spectroscopy were used to monitor the degree of cross-linking non-destructively.
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Affiliation(s)
- Tanveer Ahmed Shaik
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Alba Alfonso-Garcia
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA;
| | - Martin Richter
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;
| | - Florian Korinth
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Christoph Krafft
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
| | - Laura Marcu
- Biomedical Engineering Department, University of California Davis, Davis, CA 95616, USA;
| | - Jürgen Popp
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany; (T.A.S.); (F.K.); (C.K.)
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany;
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11
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Shaik TA, Alfonso-García A, Zhou X, Arnold KM, Haudenschild AK, Krafft C, Griffiths LG, Popp J, Marcu L. FLIm-Guided Raman Imaging to Study Cross-Linking and Calcification of Bovine Pericardium. Anal Chem 2020; 92:10659-10667. [PMID: 32598134 PMCID: PMC7539574 DOI: 10.1021/acs.analchem.0c01772] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bovine pericardium (BP) is a vascular biomaterial used in cardiovascular surgery that is typically cross-linked for masking antigenicity and enhance stability. There is a need for biochemical evaluation of the tissue properties prior to implantation to ensure that quality and reliability standards are met. Here, engineered antigen removed BP (ARBP) that was cross-linked with 0.2% and 0.6% glutaraldehyde (GA), and further calcified in vitro to simulate graft calcifications upon implantation was characterized nondestructively using fluorescence lifetime imaging (FLIm) to identify regions of interest which were then assessed by Raman spectroscopy. We observed that the tissue fluorescence lifetime shortened, and that Raman bands at 856, 935, 1282, and 1682 cm-1 decreased, and at 1032 and 1627 cm-1 increased with increasing GA cross-linking. Independent classification analysis based on fluorescence lifetime and on Raman spectra discriminated between GA-ARBP and untreated ARBP with an accuracy of 91% and 66%, respectively. Pearson's correlation analysis showed a strong correlation between pyridinium cross-links measured with high-performance liquid chromatography and fluorescence lifetime measured at 380-400 nm (R = -0.76, p = 0.00094), as well as Raman bands at 856 cm-1 for hydroxy-proline (R = -0.68, p = 0.0056) and at 1032 cm-1 for hydroxy-pyridinium (R = 0.74, p = 0.0016). Calcified areas of GA cross-linked tissue showed characteristic hydroxyapatite (959 and 1038 cm-1) bands in the Raman spectrum and fluorescence lifetime shortened by 0.4 ns compared to uncalcified regions. FLIm-guided Raman imaging could rapidly identify degrees of cross-linking and detected calcified regions with high chemical specificity, an ability that can be used to monitor tissue engineering processes for applications in regenerative medicine.
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Affiliation(s)
- Tanveer Ahmed Shaik
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - Alba Alfonso-García
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Xiangnan Zhou
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Katherine M Arnold
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Anne K Haudenschild
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Christoph Krafft
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
| | - Leigh G Griffiths
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Jürgen Popp
- Leibniz Institute of Photonic Technology Jena e.V., Albert-Einstein-Strasse 9, 07745 Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, California 95616, United States
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12
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Tian Z, Shen L, Liu W, Li G. Construction of collagen gel with high viscoelasticity and thermal stability via combining cross-linking and dehydration. J Biomed Mater Res A 2020; 108:1934-1943. [PMID: 32319162 DOI: 10.1002/jbm.a.36956] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 03/17/2020] [Accepted: 03/28/2020] [Indexed: 11/09/2022]
Abstract
Collagen gel is widely used in tissue engineering due to excellent biological properties and swollen three-dimensional network structure. To improve viscoelasticity and thermal stability, collagen gels consisting of fibrils were cross-linked with glutaraldehyde and sequentially dehydrated via ethanol or heating (named as EGC or HGC, respectively). For EGC, ethanol replaced free and loosely bound water and then combined with tightly bound water, inducing the increase in hydrogen bonds and molecular interactions. Therefore, the thermal transition temperature (Tt ) and storage modulus (G') obviously increased from 47.3 ± 0.5°C and 0.1 kPa to 92.7 ± 0.8°C and 7.8 kPa, respectively. Unfortunately, the high deformation (γ > 60%) and low recovery percentage (R < 15%) reflected the poor anti-deformation of gels due to the volatility of ethanol. For HGC, the entanglement and rigidity of fibrils increased owing to the contraction of cross-linked fibrils and cohesive action of denatured collagen. As a result, HGC were more resistant to deformation and exhibited more elasticity than native collagen gel, accompanied by the fact that G' and R increased to 28.8 kPa and 90.0% ± 0.7%. Additionally, HGC exhibited higher Tt (121.4 ± 0.5°C) due to lower water content and higher collagen concentration.
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Affiliation(s)
- Zhenhua Tian
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, China.,National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an, China.,College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Lirui Shen
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, China
| | - Wentao Liu
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, China
| | - Guoying Li
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, China
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13
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Blair MJ, Jones JD, Woessner AE, Quinn KP. Skin Structure-Function Relationships and the Wound Healing Response to Intrinsic Aging. Adv Wound Care (New Rochelle) 2020; 9:127-143. [PMID: 31993254 DOI: 10.1089/wound.2019.1021] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 08/09/2019] [Indexed: 02/06/2023] Open
Abstract
Significance: Chronic wounds, such as diabetic foot ulcers, venous stasis ulcers, and pressure ulcers affect millions of Americans each year, and disproportionately afflict our increasingly older population. Older individuals are predisposed to wound infection, repeated trauma, and the development of chronic wounds. However, a complete understanding of how the attributes of aging skin affect the wound healing process has remained elusive. Recent Advances: A variety of studies have demonstrated that the dermal matrix becomes thinner, increasingly crosslinked, and fragmented with advanced age. These structural changes, as well as an increase in cell senescence, result in altered collagen fiber remodeling and increased stiffness. Studies combining mechanical testing with advanced imaging techniques are providing new insights into the relationships between these age-related changes. Emerging research into the mechanobiology of aging and the wound healing process indicate that the altered mechanical environment of aged skin may have a significant effect on age-related delays in healing. Critical Issues: The interpretation and synthesis of clinical studies is confounded by the effects of common comorbidities that also contribute to the development of chronic wounds. A lack of quantitative biomarkers of wound healing and age-related changes makes understanding structure-function relationships during the wound healing process challenging. Future Directions: Additional work is needed to establish quantitative and mechanistic relationships among age-related changes in the skin microstructure, mechanical function, and the cellular responses to wound healing.
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Affiliation(s)
- Michael J. Blair
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Jake D. Jones
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Alan E. Woessner
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Kyle P. Quinn
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, Arkansas
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14
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Li C, Alfonso-Garcia A, McMasters J, Bec J, Weyers B, Uyesaka L, Griffiths L, Panitch A, Marcu L. Simultaneous intraluminal imaging of tissue autofluorescence and eGFP-labeled cells in engineered vascular grafts inside a bioreactor. Methods Appl Fluoresc 2019; 7:044003. [PMID: 31505471 DOI: 10.1088/2050-6120/ab4342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The growing demand for tissue engineered vascular grafts (TEVG) motivates the development of optimized fabrication and monitoring procedures. Bioreactors which provide physiologically-relevant conditions are important for improving holistic TEVG properties and performance. Herein we describe a fiber-based intraluminal imaging system that allows for in situ assessment of vascular materials and re-cellularization processes inside a bioreactor by simultaneous and co-registered measurements of endogenous fluorescence lifetime and exogenous marker fluorescence intensity. The lumen of 6 vascular grafts (∼4 mm diameter) were scanned by reciprocally rotating a 41° angle polished multimode optical fiber inside a protective glass tube with outer diameter of 3 mm. Tubular bovine pericardium constructs were recellularized using enhanced Green Fluorescent Protein (eGFP) transfected cells in a custom bioreactor. The imaging system has resolved consistently the cellular autofluorescence from that of tissue matrix in situ based on the lifetime fluorescence properties of endogenous molecular species. The location of the re-cellularized area was validated by the eGFP emission. Current results demonstrate the potential of this system as a valuable tool in tissue engineering for in situ studies of cell-tissue interactions in cylindrical or other 3-dimensional structures.
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Affiliation(s)
- Cai Li
- Department of Material Science and Engineering, University of California, Davis, United States of America
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15
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Sherlock BE, Li C, Zhou X, Alfonso-Garcia A, Bec J, Yankelevich D, Marcu L. Multiscale, multispectral fluorescence lifetime imaging using a double-clad fiber. OPTICS LETTERS 2019; 44:2302-2305. [PMID: 31042209 PMCID: PMC7539568 DOI: 10.1364/ol.44.002302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fiber-based imaging of tissue autofluorescence using ultraviolet (UV) excitation is a highly flexible tool used to probe structure and composition. In this Letter, we report, to the best of our knowledge, the first results from a single-fiber imaging system employing a custom double-clad fiber to acquire multispectral fluorescence lifetime images at two distinct spatial resolutions. We characterize the lateral point spread function and fluorescent background of the system and show how enhanced resolution can identify features such as trabeculae in ex vivo murine bone samples.
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Affiliation(s)
- Benjamin E. Sherlock
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Cai Li
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Xiangnan Zhou
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Alba Alfonso-Garcia
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Julien Bec
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Diego Yankelevich
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
- Department of Electrical and Computer Engineering, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
| | - Laura Marcu
- Genome and Biomedical Sciences Facility, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, USA
- Corresponding author:
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16
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Almouemen N, Kelly HM, O'Leary C. Tissue Engineering: Understanding the Role of Biomaterials and Biophysical Forces on Cell Functionality Through Computational and Structural Biotechnology Analytical Methods. Comput Struct Biotechnol J 2019; 17:591-598. [PMID: 31080565 PMCID: PMC6502738 DOI: 10.1016/j.csbj.2019.04.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/26/2019] [Accepted: 04/13/2019] [Indexed: 12/13/2022] Open
Abstract
Within the past 25 years, tissue engineering (TE) has grown enormously as a science and as an industry. Although classically concerned with the recapitulation of tissue and organ formation in our body for regenerative medicine, the evolution of TE research is intertwined with progress in other fields through the examination of cell function and behaviour in isolated biomimetic microenvironments. As such, TE applications now extend beyond the field of tissue regeneration research, operating as a platform for modifiable, physiologically-representative in vitro models with the potential to improve the translation of novel therapeutics into the clinic through a more informed understanding of the relevant molecular biology, structural biology, anatomy, and physiology. By virtue of their biomimicry, TE constructs incorporate features of extracellular macrostructure, molecular adhesive moieties, and biomechanical properties, converging with computational and structural biotechnology advances. Accordingly, this mini-review serves to contextualise TE for the computational and structural biotechnology reader and provides an outlook on how the disciplines overlap with respect to relevant advanced analytical applications.
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Affiliation(s)
- Nour Almouemen
- School of Pharmacy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
- Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin 2, Ireland
| | - Helena M. Kelly
- School of Pharmacy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
- Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Cian O'Leary
- School of Pharmacy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
- Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin 2, Ireland
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17
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Harvestine JN, Sheaff CS, Li C, Haudenschild AK, Gionet-Gonzales MA, Hu JC, Athanasiou KA, Marcu L, Leach JK. Multimodal Label-Free Imaging for Detecting Maturation of Engineered Osteogenic Grafts. ACS Biomater Sci Eng 2019; 5:1956-1966. [PMID: 33405522 PMCID: PMC8594456 DOI: 10.1021/acsbiomaterials.9b00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
There is a critical need to develop noninvasive, nondestructive methods for assessing the quality of engineered constructs prior to implantation. Currently, the composition and maturity of engineered tissues are assessed using destructive, costly, and time-consuming biochemical and mechanical analyses. The goal of this study was to use noninvasive, multimodal imaging to monitor osteogenic differentiation and matrix deposition by human mesenchymal stem/stromal cells (MSCs) during in vitro culture. MSCs were encapsulated in alginate hydrogels and cultured in osteogenic conditions for 4 weeks. Samples were evaluated using fluorescence lifetime imaging (FLIm) and ultrasound backscatter microscopy (UBM) prior to traditional biochemical and mechanical testing. Using linear regression analysis, we identified strong correlations between imaging parameters (e.g., fluorescence lifetime and acoustic attenuation coefficient) and destructive mechanical and biochemical tests to assess the maturation of osteogenically induced constructs. These data demonstrate the promise of nondestructive label-free imaging techniques to noninvasively ascertain the progression and maturity of tissue engineered bone grafts.
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Affiliation(s)
- Jenna N. Harvestine
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Clay S. Sheaff
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Cai Li
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Anne K. Haudenschild
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Marissa A. Gionet-Gonzales
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Jerry C. Hu
- Department of Biomedical Engineering, University of California, Irvine, Irvine California 92697, United States
| | - Kyriacos A. Athanasiou
- Department of Biomedical Engineering, University of California, Irvine, Irvine California 92697, United States
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
| | - J. Kent Leach
- Department of Biomedical Engineering, University of California, Davis, Davis, California 95616, United States
- Department of Orthopaedic Surgery, School of Medicine, UC Davis Health, Sacramento, California 95817, United States
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18
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Haudenschild AK, Sherlock BE, Zhou X, Hu JC, Leach JK, Marcu L, Athanasiou KA. Non-destructive detection of matrix stabilization correlates with enhanced mechanical properties of self-assembled articular cartilage. J Tissue Eng Regen Med 2019; 13:637-648. [PMID: 30770656 DOI: 10.1002/term.2824] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 12/05/2018] [Accepted: 02/13/2019] [Indexed: 11/10/2022]
Abstract
Tissue engineers rely on expensive, time-consuming, and destructive techniques to monitor the composition, microstructure, and function of engineered tissue equivalents. A non-destructive solution to monitor tissue quality and maturation would greatly reduce costs and accelerate the development of tissue-engineered products. The objectives of this study were to (a) determine whether matrix stabilization with exogenous lysyl oxidase-like protein-2 (LOXL2) with recombinant hyaluronan and proteoglycan link protein-1 (LINK) would result in increased compressive and tensile properties in self-assembled articular cartilage constructs, (b) evaluate whether label-free, non-destructive fluorescence lifetime imaging (FLIm) could be used to infer changes in both biochemical composition and biomechanical properties, (c) form quantitative relationships between destructive and non-destructive measurements to determine whether the strength of these correlations is sufficient to replace destructive testing methods, and (d) determine whether support vector machine (SVM) learning can predict LOXL2-induced collagen crosslinking. The combination of exogenous LOXL2 and LINK proteins created a synergistic 4.9-fold increase in collagen crosslinking density and an 8.3-fold increase in tensile strength as compared with control (CTL). Compressive relaxation modulus was increased 5.9-fold with addition of LOXL2 and 3.4-fold with combined treatments over CTL. FLIm parameters had strong and significant correlations with tensile properties (R2 = 0.82; p < 0.001) and compressive properties (R2 = 0.59; p < 0.001). SVM learning based on FLIm-derived parameters was capable of automating tissue maturation assessment with a discriminant ability of 98.4%. These results showed marked improvements in mechanical properties with matrix stabilization and suggest that FLIm-based tools have great potential for the non-destructive assessment of tissue-engineered cartilage.
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Affiliation(s)
- Anne K Haudenschild
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Benjamin E Sherlock
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Xiangnan Zhou
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Jerry C Hu
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
| | - J Kent Leach
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA.,Department of Orthopaedic Surgery, University of California Davis Medical Center, Sacramento, CA, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Kyriacos A Athanasiou
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
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19
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Alfonso-Garcia A, Haudenschild AK, Marcu L. Label-free assessment of carotid artery biochemical composition using fiber-based fluorescence lifetime imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:4064-4076. [PMID: 30615748 PMCID: PMC6157793 DOI: 10.1364/boe.9.004064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/11/2018] [Accepted: 07/12/2018] [Indexed: 05/08/2023]
Abstract
Novel diagnostic tools with the ability to monitor variations in biochemical composition and provide benchmark indicators of vascular tissue maturation are needed to create functional tissue replacements. We investigated the ability of fiber-based, label-free multispectral fluorescent lifetime imaging (FLIm) to quantify the anatomical variations in biochemical composition of native carotid arteries and validated these results against biochemical assays. FLIm-derived parameters in spectral band 415-455 nm correlated with tissue collagen content (R2 = 0.64) and cell number (R2 = 0.61) and in spectral band 465-553 nm strongly correlated with elastin content (R2 = 0.89). These results suggest that FLIm holds great potential for assessing vascular tissue maturation and functional properties based on tissue autofluorescence.
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Affiliation(s)
- Alba Alfonso-Garcia
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
- Authors contributed equally to this work
| | - Anne K. Haudenschild
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
- Authors contributed equally to this work
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., Davis, CA 95616,
USA
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