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A reductionist approach to determine the effect of cell-cell contact on human epidermal stem cell differentiation. Acta Biomater 2022; 150:265-276. [PMID: 35926780 PMCID: PMC9810539 DOI: 10.1016/j.actbio.2022.07.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 07/23/2022] [Accepted: 07/27/2022] [Indexed: 01/07/2023]
Abstract
The balance between stem cell renewal and differentiation is determined by the interplay between intrinsic cellular controls and extrinsic factors presented by the microenvironment, or 'niche'. Previous studies on cultured human epidermis have utilised suspension culture and restricted cell spreading to investigate regulation of differentiation in single keratinocytes. However, keratinocytes are typically adherent to neighbouring cells in vivo. We therefore developed experimental models to investigate the combined effects of cell-ECM adhesion and cell-cell contact. We utilized lipid-modified oligonucleotides to form clusters of keratinocytes which were subsequently placed in suspension to induce terminal differentiation. In this experimental model cell-cell contact had no effect on suspension-induced differentiation of keratinocytes. We next developed a high-throughput platform for robust geometrical confinement of keratinocytes to hexagonal ECM-coated islands permitting direct cell-cell contact between single cells. As in the case of circular islands, differentiation was stimulated on the smallest single hexagonal islands. However, the percentage of involucrin-positive cells on small bowtie islands was significantly lower than on single islands, demonstrating that cell-cell contact reduced differentiation in response to decreased substrate adhesion. None of the small bowtie islands contained two involucrin-positive cells. Rather, if one cell was involucrin-positive the other was involucrin-negative. This suggests that there is intrinsic asymmetry in the effect of cell-cell contact in decreasing differentiation. Thus, our reductionist approaches provide new insights into the effect of the niche on keratinocyte differentiation. STATEMENT OF SIGNIFICANCE: Stem cell behaviour is regulated by a combination of external signals, including the nature of the adhesive substrate and cell-cell interactions. An understanding of how different signals are integrated creates the possibility of developing new biomaterials to promote tissue regeneration and broaden our understanding of skin diseases such as eczema and psoriasis, in which stem cell proliferation and differentiation are perturbed. In this study we have applied two methods to engineer intercellular adhesion of human epidermal stem cells, one involving lipid-modified DNA and the other involving hexagonal micropatterns. We show that the effect of cell-cell adhesion depends on cell-substrate adhesion and uncover evidence that two cells in equivalent environments can nevertheless behave differently.
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2
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Zhu M, Zhang R, Mao Z, Fang J, Ren F. Topographical biointerface regulating cellular functions for bone tissue engineering. BIOSURFACE AND BIOTRIBOLOGY 2022. [DOI: 10.1049/bsb2.12043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Mingyu Zhu
- Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong China
| | - Rui Zhang
- Department of Prosthodontics Stomatology Center Peking University Shenzhen Hospital Shenzhen Guangdong China
| | - Zhixiang Mao
- Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong China
| | - Ju Fang
- Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong China
| | - Fuzeng Ren
- Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong China
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3
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Jones CFE, Di Cio S, Connelly JT, Gautrot JE. Design of an Integrated Microvascularized Human Skin-on-a-Chip Tissue Equivalent Model. Front Bioeng Biotechnol 2022; 10:915702. [PMID: 35928950 PMCID: PMC9343775 DOI: 10.3389/fbioe.2022.915702] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
Tissue-engineered skin constructs have been under development since the 1980s as a replacement for human skin tissues and animal models for therapeutics and cosmetic testing. These have evolved from simple single-cell assays to increasingly complex models with integrated dermal equivalents and multiple cell types including a dermis, epidermis, and vasculature. The development of micro-engineered platforms and biomaterials has enabled scientists to better recreate and capture the tissue microenvironment in vitro, including the vascularization of tissue models and their integration into microfluidic chips. However, to date, microvascularized human skin equivalents in a microfluidic context have not been reported. Here, we present the design of a novel skin-on-a-chip model integrating human-derived primary and immortalized cells in a full-thickness skin equivalent. The model is housed in a microfluidic device, in which a microvasculature was previously established. We characterize the impact of our chip design on the quality of the microvascular networks formed and evidence that this enables the formation of more homogenous networks. We developed a methodology to harvest tissues from embedded chips, after 14 days of culture, and characterize the impact of culture conditions and vascularization (including with pericyte co-cultures) on the stratification of the epidermis in the resulting skin equivalents. Our results indicate that vascularization enhances stratification and differentiation (thickness, architecture, and expression of terminal differentiation markers such as involucrin and transglutaminase 1), allowing the formation of more mature skin equivalents in microfluidic chips. The skin-on-a-chip tissue equivalents developed, because of their realistic microvasculature, may find applications for testing efficacy and safety of therapeutics delivered systemically, in a human context.
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Affiliation(s)
- Christian F. E. Jones
- Institute of Bioengineering, Queen Mary University of London, London, United Kingdom
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - Stefania Di Cio
- Institute of Bioengineering, Queen Mary University of London, London, United Kingdom
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
| | - John T. Connelly
- The Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Julien E. Gautrot
- Institute of Bioengineering, Queen Mary University of London, London, United Kingdom
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
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4
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Açarı İK, Sel E, Özcan İ, Ateş B, Köytepe S, Thakur VK. Chemistry and engineering of brush type polymers: Perspective towards tissue engineering. Adv Colloid Interface Sci 2022; 305:102694. [PMID: 35597039 DOI: 10.1016/j.cis.2022.102694] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/21/2022] [Accepted: 05/06/2022] [Indexed: 11/01/2022]
Abstract
In tissue engineering, it is imperative to control the behaviour of cells/stem cells, such as adhesion, proliferation, propagation, motility, and differentiation for tissue regeneration. Surfaces that allow cells to behave in this way are critical as support materials in tissue engineering. Among these surfaces, brush-type polymers have an important potential for tissue engineering and biomedical applications. Brush structure and length, end groups, bonding densities, hydrophilicity, surface energy, structural flexibility, thermal stability, surface chemical reactivity, rheological and tribological properties, electron and energy transfer ability, cell binding and absorption abilities for various biological molecules of brush-type polymers were increased its importance in tissue engineering applications. In addition, thanks to these functional properties and adjustable surface properties, brush type polymers are used in different high-tech applications such as electronics, sensors, anti-fouling, catalysis, purification and energy etc. This review comprehensively highlights the use of brush-type polymers in tissue engineering applications. Considering the superior properties of brush-type polymer structures, it is believed that in the future, it will be an effective tool in structure designs containing many different biomolecules (enzymes, proteins, etc.) in the field of tissue engineering.
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5
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Zijl S, Salameti V, Louis B, Negri VA, Watt FM. Dynamic regulation of human epidermal differentiation by adhesive and mechanical forces. Curr Top Dev Biol 2022; 150:129-148. [DOI: 10.1016/bs.ctdb.2022.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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Aleemardani M, Trikić MZ, Green NH, Claeyssens F. The Importance of Mimicking Dermal-Epidermal Junction for Skin Tissue Engineering: A Review. Bioengineering (Basel) 2021; 8:bioengineering8110148. [PMID: 34821714 PMCID: PMC8614934 DOI: 10.3390/bioengineering8110148] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 12/11/2022] Open
Abstract
There is a distinct boundary between the dermis and epidermis in the human skin called the basement membrane, a dense collagen network that creates undulations of the dermal-epidermal junction (DEJ). The DEJ plays multiple roles in skin homeostasis and function, namely, enhancing the adhesion and physical interlock of the layers, creating niches for epidermal stem cells, regulating the cellular microenvironment, and providing a physical boundary layer between fibroblasts and keratinocytes. However, the primary role of the DEJ has been determined as skin integrity; there are still aspects of it that are poorly investigated. Tissue engineering (TE) has evolved promising skin regeneration strategies and already developed TE scaffolds for clinical use. However, the currently available skin TE equivalents neglect to replicate the DEJ anatomical structures. The emergent ability to produce increasingly complex scaffolds for skin TE will enable the development of closer physical and physiological mimics to natural skin; it also allows researchers to study the DEJ effect on cell function. Few studies have created patterned substrates that could mimic the human DEJ to explore their significance. Here, we first review the DEJ roles and then critically discuss the TE strategies to create the DEJ undulating structure and their effects. New approaches in this field could be instrumental for improving bioengineered skin substitutes, creating 3D engineered skin, identifying pathological mechanisms, and producing and screening drugs.
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Affiliation(s)
- Mina Aleemardani
- Biomaterials and Tissue Engineering Group, Department of Materials Science and Engineering, Kroto Research Institute, The University of Sheffield, Sheffield S3 7HQ, UK; (M.A.); (M.Z.T.); (N.H.G.)
| | - Michael Zivojin Trikić
- Biomaterials and Tissue Engineering Group, Department of Materials Science and Engineering, Kroto Research Institute, The University of Sheffield, Sheffield S3 7HQ, UK; (M.A.); (M.Z.T.); (N.H.G.)
| | - Nicola Helen Green
- Biomaterials and Tissue Engineering Group, Department of Materials Science and Engineering, Kroto Research Institute, The University of Sheffield, Sheffield S3 7HQ, UK; (M.A.); (M.Z.T.); (N.H.G.)
- Insigneo Institute for in Silico Medicine, The Pam Liversidge Building, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
| | - Frederik Claeyssens
- Biomaterials and Tissue Engineering Group, Department of Materials Science and Engineering, Kroto Research Institute, The University of Sheffield, Sheffield S3 7HQ, UK; (M.A.); (M.Z.T.); (N.H.G.)
- Correspondence:
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7
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Poręba R, los Santos Pereira A, Pola R, Jiang S, Pop‐Georgievski O, Sedláková Z, Schönherr H. “Clickable” and Antifouling Block Copolymer Brushes as a Versatile Platform for Peptide‐Specific Cell Attachment. Macromol Biosci 2020; 20:e1900354. [DOI: 10.1002/mabi.201900354] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/16/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Rafał Poręba
- Institute of Macromolecular ChemistryCzech Academy of Sciences Heyrovsky sq. 2 Prague 162 06 Czech Republic
| | - Andres los Santos Pereira
- Institute of Macromolecular ChemistryCzech Academy of Sciences Heyrovsky sq. 2 Prague 162 06 Czech Republic
| | - Robert Pola
- Institute of Macromolecular ChemistryCzech Academy of Sciences Heyrovsky sq. 2 Prague 162 06 Czech Republic
| | - Siyu Jiang
- Physical Chemistry I and Research Center of Micro and Nanochemistry and Engineering (Cµ)Department of Chemistry and Biology, University of Siegen Adolf‐Reichwein‐Str. 2 57076 Siegen Germany
| | - Ognen Pop‐Georgievski
- Institute of Macromolecular ChemistryCzech Academy of Sciences Heyrovsky sq. 2 Prague 162 06 Czech Republic
| | - Zdeňka Sedláková
- Institute of Macromolecular ChemistryCzech Academy of Sciences Heyrovsky sq. 2 Prague 162 06 Czech Republic
| | - Holger Schönherr
- Physical Chemistry I and Research Center of Micro and Nanochemistry and Engineering (Cµ)Department of Chemistry and Biology, University of Siegen Adolf‐Reichwein‐Str. 2 57076 Siegen Germany
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8
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Thomas M, Ladoux B, Toyama Y. Desmosomal Junctions Govern Tissue Integrity and Actomyosin Contractility in Apoptotic Cell Extrusion. Curr Biol 2020; 30:682-690.e5. [DOI: 10.1016/j.cub.2020.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 10/22/2019] [Accepted: 01/02/2020] [Indexed: 10/25/2022]
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9
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Sun Q, Liu C, Bai X, Huo B. Cell-substrate traction force regulates the fusion of osteoclast precursors through cell-cell interaction. Biomech Model Mechanobiol 2019; 19:481-492. [PMID: 31529292 DOI: 10.1007/s10237-019-01223-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 08/27/2019] [Indexed: 11/28/2022]
Abstract
The adhesion morphology of a cell monolayer results in a mechanical force inside cells, between cells, or between cells and substrates. The mechanical force regulates the differentiation of stem cells, but its influence on cell fusion is seldom studied. The present study is focused on osteoclast precursors, RAW264.7 monocytes, which can fuse into multinucleated cells (MNCs) responsible for bone resorption. Cells were cultured on circular and ring-like patterned substrates. Then, cell fusion, cell-substrate traction force, and force-sensitive molecules in different regions were measured and analyzed. Results showed that MNCs mainly appeared in the interior of the ring-like pattern and the central zone of the circular pattern, where both cell-substrate traction force and in-plane maximal shear stress were smaller than that at the patterns' edge. The immunostaining results revealed that F-actin, vinculin, β-catenin, and E-cadherin were highly distributed at the edge of patterns. High seeding density of cells promoted mechanical force-dependent fusion. When calcium-dependent cell-cell connections were inhibited by E-cadherin antibody or low-calcium medium, the fusion into MNCs was greatly reduced. Thus, the morphology of cell monolayer decides the mechanical state of cell-substrate interaction and cell-cell connection, ultimately regulating the fusion of osteoclast precursors.
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Affiliation(s)
- Qing Sun
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Chengling Liu
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Xue Bai
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, People's Republic of China
| | - Bo Huo
- Biomechanics Lab, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, People's Republic of China.
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10
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Yan W, Fantin M, Ramakrishna S, Spencer ND, Matyjaszewski K, Benetti EM. Growing Polymer Brushes from a Variety of Substrates under Ambient Conditions by Cu 0-Mediated Surface-Initiated ATRP. ACS APPLIED MATERIALS & INTERFACES 2019; 11:27470-27477. [PMID: 31276375 DOI: 10.1021/acsami.9b09529] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Cu0-mediated surface-initiated atom transfer radical polymerization (Cu0 SI-ATRP) is a highly versatile, oxygen-tolerant, and extremely controlled polymer-grafting technique that enables the modification of flat inorganic surfaces, as well as porous organic and polymeric supports of different compositions. Exploiting the intimate contact between a copper plate, acting as a source of catalyst and reducing agent, and an initiator-bearing support, Cu0 SI-ATRP enables the rapid growth of biopassive, lubricious brushes from large flat surfaces, as well as from various organic supports, including cellulose fibers and elastomers, using microliter volumes of reaction mixtures, and without the need for deoxygenation of reaction mixtures or an inert atmosphere. Thanks to a detailed analysis of its mechanism and the parameters governing the polymerization process, polymer brush growth by Cu0 SI-ATRP can be precisely modulated and adapted to be applied to morphologically and chemically different substrates, setting up the basis for translating SI-ATRP methods from academic studies into technologically relevant surface-modification approaches.
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Affiliation(s)
- Wenqing Yan
- Laboratory of Surface Science and Technology, Department of Materials , Swiss Federal Institute of Technology (ETH Zürich) , Vladimir-Prelog-Weg 1-5/10 , Zurich CH-8093 , Switzerland
| | - Marco Fantin
- Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Shivaprakash Ramakrishna
- Laboratory of Surface Science and Technology, Department of Materials , Swiss Federal Institute of Technology (ETH Zürich) , Vladimir-Prelog-Weg 1-5/10 , Zurich CH-8093 , Switzerland
| | - Nicholas D Spencer
- Laboratory of Surface Science and Technology, Department of Materials , Swiss Federal Institute of Technology (ETH Zürich) , Vladimir-Prelog-Weg 1-5/10 , Zurich CH-8093 , Switzerland
| | - Krzysztof Matyjaszewski
- Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Edmondo M Benetti
- Laboratory of Surface Science and Technology, Department of Materials , Swiss Federal Institute of Technology (ETH Zürich) , Vladimir-Prelog-Weg 1-5/10 , Zurich CH-8093 , Switzerland
- Laboratory for Biointerfaces , Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5 , St. Gallen CH-9014 , Switzerland
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11
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Santos DES, Li D, Ramstedt M, Gautrot JE, Soares TA. Conformational Dynamics and Responsiveness of Weak and Strong Polyelectrolyte Brushes: Atomistic Simulations of Poly(dimethyl aminoethyl methacrylate) and Poly(2-(methacryloyloxy)ethyl trimethylammonium chloride). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5037-5049. [PMID: 30869897 DOI: 10.1021/acs.langmuir.8b04268] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The complex solution behavior of polymer brushes is key to control their properties, including for biomedical applications and catalysis. The swelling behavior of poly(dimethyl aminoethyl methacrylate) (PDMAEMA) and poly(2-(methacryloyloxy)ethyl trimethylammonium chloride) (PMETAC) in response to changes in pH, solvent, and salt types has been investigated using atomistic molecular dynamics simulations. PDMAEMA and PMETAC have been selected as canonical models for weak and strong polyelectrolytes whose complex conformational behavior is particularly challenging for the development and validation of atomistic models. The GROMOS-derived atomic parameters reproduce the experimental swelling coefficients obtained from ellipsometry measurements for brushes of 5-15 nm thickness. The present atomistic models capture the protonated morphology of PDMAEMA, the swollen and collapsed conformations of PDMAEMA and PMETAC in good and bad solvents, and the salt-selective response of PMETAC. The modular nature of the molecular models allows for the simple extension of atomic parameters to a variety of polymers or copolymers.
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Affiliation(s)
- Denys E S Santos
- Departamento de Química Fundamental , Universidade Federal de Pernambuco , Cidade Universitária, 50670-901 Recife , Brazil
| | | | | | | | - Thereza A Soares
- Departamento de Química Fundamental , Universidade Federal de Pernambuco , Cidade Universitária, 50670-901 Recife , Brazil
- Department of Chemistry , Umeå University , 90187 Umeå , Sweden
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12
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Mobasseri SA, Zijl S, Salameti V, Walko G, Stannard A, Garcia-Manyes S, Watt FM. Patterning of human epidermal stem cells on undulating elastomer substrates reflects differences in cell stiffness. Acta Biomater 2019; 87:256-264. [PMID: 30710711 PMCID: PMC6401207 DOI: 10.1016/j.actbio.2019.01.063] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/15/2019] [Accepted: 01/29/2019] [Indexed: 11/27/2022]
Abstract
In human skin the junction between epidermis and dermis undulates, the width and depth of the undulations varying with age and disease. When primary human epidermal keratinocytes are seeded on collagen-coated polydimethylsiloxane (PDMS) elastomer substrates that mimic the epidermal-dermal interface, the stem cells become patterned by 24 h, resembling their organisation in living skin. We found that cell density and nuclear height were higher at the base than the tips of the PDMS features. Cells on the tips not only expressed higher levels of the stem cell marker β1 integrin but also had elevated E-cadherin, Desmoglein 3 and F-actin than cells at the base. In contrast, levels of the transcriptional cofactor MAL were higher at the base. AFM measurements established that the Young’s modulus of cells on the tips was lower than on the base or cells on flat substrates. The differences in cell stiffness were dependent on Rho kinase activity and intercellular adhesion. On flat substrates the Young’s modulus of calcium-dependent intercellular junctions was higher than that of the cell body, again dependent on Rho kinase. Cell patterning was influenced by the angle of the slope on undulating substrates. Our observations are consistent with the concept that epidermal stem cell patterning is dependent on mechanical forces exerted at intercellular junctions in response to undulations in the epidermal-dermal interface. Statement of significance In human skin the epidermal-dermal junction undulates and epidermal stem cells are patterned according to their position. We previously created collagen-coated polydimethylsiloxane (PDMS) elastomer substrates that mimic the undulations and provide sufficient topographical information for stem cells to cluster on the tips. Here we show that the stiffness of cells on the tips is lower than cells on the base. The differences in cell stiffness depend on Rho kinase activity and intercellular adhesion. We propose that epidermal stem cell patterning is determined by mechanical forces exerted at intercellular junctions in response to the slope of the undulations.
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13
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Tang P, di Cio S, Wang W, E Gautrot J. Surface-Initiated Poly(oligo(2-alkyl-2-oxazoline)methacrylate) Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10019-10027. [PMID: 30032621 DOI: 10.1021/acs.langmuir.8b01682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Polymer brushes are particularly performant antifouling coatings, owing to their high grafting density that prevents unwanted biomacromolecules to diffuse through the coating and adhere to the underlying substrate. In addition to this structural feature, polymer brushes require a relatively high level of hydrophilicity and a globally neutral structure to display ultrahigh protein resistance. Poly(2-alkyl-2-oxaolines) are attractive building blocks for such coatings as they can display relatively high hydrophilicity, owing to their amide repeat units, but can also be side-chain and end-chain functionalized relatively readily. However, poly(2-alkyl-2-oxazolines) have not yet been introduced through a radical-mediated grafting from polymer brush structure that would confer the high level of grafting density that is the hallmark of highly protein resistant brushes. Here, we present the formation of a series of poly(oligo(2-alkyl-2-oxazoline)methacrylate) brushes generated via a grafting from approach, via atom transfer radical polymerization. We characterize the chemical structure of the resulting coatings via ellipsometry, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. We show that allyl end groups can be introduced as a side chain of these brushes to allow functionalization via thiol-ene chemistry. We demonstrate the excellent protein resistance of these coatings in single protein solutions as well as serum solutions at concentration typically used for cell culture. Finally, we demonstrate the feasibility of using these brushes for the micropatterning of cells and the generation of cell-based assays.
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14
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Bao M, Xie J, Huck WTS. Recent Advances in Engineering the Stem Cell Microniche in 3D. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1800448. [PMID: 30128252 PMCID: PMC6096985 DOI: 10.1002/advs.201800448] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/01/2018] [Indexed: 05/18/2023]
Abstract
Conventional 2D cell culture techniques have provided fundamental insights into key biochemical and biophysical mechanisms responsible for various cellular behaviors, such as cell adhesion, spreading, division, proliferation, and differentiation. However, 2D culture in vitro does not fully capture the physical and chemical properties of the native microenvironment. There is a growing body of research that suggests that cells cultured on 2D substrates differ greatly from those grown in vivo. This article focuses on recent progress in using bioinspired 3D matrices that recapitulate as many aspects of the natural extracellular matrix as possible. A range of techniques for the engineering of 3D microenvironment with precisely controlled biophysical and chemical properties, and the impact of these environments on cellular behavior, is reviewed. Finally, an outlook on future challenges for engineering the 3D microenvironment and how such approaches would further our understanding of the influence of the microenvironment on cell function is provided.
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Affiliation(s)
- Min Bao
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| | - Jing Xie
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| | - Wilhelm T. S. Huck
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
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15
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Li D, Sharili AS, Connelly J, Gautrot JE. Highly Stable RNA Capture by Dense Cationic Polymer Brushes for the Design of Cytocompatible, Serum-Stable SiRNA Delivery Vectors. Biomacromolecules 2018; 19:606-615. [DOI: 10.1021/acs.biomac.7b01686] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
| | - Amir S. Sharili
- Barts
and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - John Connelly
- Barts
and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
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16
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Colak B, Di Cio S, Gautrot JE. Biofunctionalized Patterned Polymer Brushes via Thiol–Ene Coupling for the Control of Cell Adhesion and the Formation of Cell Arrays. Biomacromolecules 2018; 19:1445-1455. [DOI: 10.1021/acs.biomac.7b01436] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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Adhesion forces and cortical tension couple cell proliferation and differentiation to drive epidermal stratification. Nat Cell Biol 2017; 20:69-80. [PMID: 29230016 DOI: 10.1038/s41556-017-0005-z] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/05/2017] [Indexed: 12/22/2022]
Abstract
To establish and maintain organ structure and function, tissues need to balance stem cell proliferation and differentiation rates and coordinate cell fate with position. By quantifying and modelling tissue stress and deformation in the mammalian epidermis, we find that this balance is coordinated through local mechanical forces generated by cell division and delamination. Proliferation within the basal stem/progenitor layer, which displays features of a jammed, solid-like state, leads to crowding, thereby locally distorting cell shape and stress distribution. The resulting decrease in cortical tension and increased cell-cell adhesion trigger differentiation and subsequent delamination, reinstating basal cell layer density. After delamination, cells establish a high-tension state as they increase myosin II activity and convert to E-cadherin-dominated adhesion, thereby reinforcing the boundary between basal and suprabasal layers. Our results uncover how biomechanical signalling integrates single-cell behaviours to couple proliferation, cell fate and positioning to generate a multilayered tissue.
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18
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Divandari M, Morgese G, Trachsel L, Romio M, Dehghani ES, Rosenboom JG, Paradisi C, Zenobi-Wong M, Ramakrishna SN, Benetti EM. Topology Effects on the Structural and Physicochemical Properties of Polymer Brushes. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01720] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
| | - Giulia Morgese
- Cartilage
Engineering + Regeneration Laboratory, Department of Health Sciences
and Technology, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland
| | - Lucca Trachsel
- Cartilage
Engineering + Regeneration Laboratory, Department of Health Sciences
and Technology, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland
| | - Matteo Romio
- Department
of Chemical Sciences, University of Padova, via Marzolo 1, 35030 Padova, Italy
| | | | | | - Cristina Paradisi
- Department
of Chemical Sciences, University of Padova, via Marzolo 1, 35030 Padova, Italy
| | - Marcy Zenobi-Wong
- Cartilage
Engineering + Regeneration Laboratory, Department of Health Sciences
and Technology, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland
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19
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Watt FM. Engineered Microenvironments to Direct Epidermal Stem Cell Behavior at Single-Cell Resolution. Dev Cell 2017; 38:601-9. [PMID: 27676433 DOI: 10.1016/j.devcel.2016.08.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/08/2016] [Accepted: 08/22/2016] [Indexed: 01/08/2023]
Abstract
Mammalian epidermis is maintained through proliferation of stem cells and differentiation of their progeny. The balance between self-renewal and differentiation is controlled by a variety of interacting intrinsic and extrinsic factors. Although the nature of these interactions is complex, they can be modeled in a reductionist fashion by capturing single epidermal stem cells on micropatterned substrates and exposing them to individual stimuli, alone or in combination, over defined time points. These studies have shown that different extrinsic stimuli trigger a common outcome-initiation of terminal differentiation-by activating different signaling pathways and eliciting different transcriptional responses.
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Affiliation(s)
- Fiona M Watt
- Centre for Stem Cells and Regenerative Medicine, King's College London, Guy's Hospital, Floor 28, Tower Wing, Great Maze Pond, London SE1 9RT, UK.
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20
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A genome-wide screen identifies YAP/WBP2 interplay conferring growth advantage on human epidermal stem cells. Nat Commun 2017; 8:14744. [PMID: 28332498 PMCID: PMC5376649 DOI: 10.1038/ncomms14744] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 01/26/2017] [Indexed: 01/13/2023] Open
Abstract
Individual human epidermal cells differ in their self-renewal ability. To uncover the molecular basis for this heterogeneity, we performed genome-wide pooled RNA interference screens and identified genes conferring a clonal growth advantage on normal and neoplastic (cutaneous squamous cell carcinoma, cSCC) human epidermal cells. The Hippo effector YAP was amongst the top positive growth regulators in both screens. By integrating the Hippo network interactome with our data sets, we identify WW-binding protein 2 (WBP2) as an important co-factor of YAP that enhances YAP/TEAD-mediated gene transcription. YAP and WPB2 are upregulated in actively proliferating cells of mouse and human epidermis and cSCC, and downregulated during terminal differentiation. WBP2 deletion in mouse skin results in reduced proliferation in neonatal and wounded adult epidermis. In reconstituted epidermis YAP/WBP2 activity is controlled by intercellular adhesion rather than canonical Hippo signalling. We propose that defective intercellular adhesion contributes to uncontrolled cSCC growth by preventing inhibition of YAP/WBP2.
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21
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Di Cio S, Bøggild TML, Connelly J, Sutherland DS, Gautrot JE. Differential integrin expression regulates cell sensing of the matrix nanoscale geometry. Acta Biomater 2017; 50:280-292. [PMID: 27940195 DOI: 10.1016/j.actbio.2016.11.069] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 12/28/2022]
Abstract
The nanoscale geometry and topography of the extra-cellular matrix (ECM) is an important parameter controlling cell adhesion and phenotype. Similarly, integrin expression and the geometrical maturation of adhesions they regulate have been correlated with important changes in cell spreading and phenotype. However, how integrin expression controls the nanoscale sensing of the ECM geometry is not clearly understood. Here we develop a new nanopatterning technique, electrospun nanofiber lithography (ENL), which allows the production of a quasi-2D fibrous nanopattern with controlled dimensions (250-1000nm) and densities. ENL relies on electrospun fibres to act as a mask for the controlled growth of protein-resistant polymer brushes. SEM, AFM and immunofluorescence imaging were used to characterise the resulting patterns and the adsorption of the extra-cellular matrix protein fibronectin to the patterned fibres. The control of adhesion formation was studied, as well as the remodelling and deposition of novel matrix. Cell spreading was found to be regulated by the size of fibres, similarly to previous observations made on circular nanopatterns. However, cell shape and polarity were more significantly affected. These changes correlated with important cytoskeleton reorganisation, with a gradual decrease in stress fibre formation as the pattern dimensions decrease. Finally, the differential expression of αvβ3 and α5β1 integrins in engineered cell lines was found to be an important mediator of cell sensing of the nanoscale geometry of the ECM. STATEMENT OF SIGNIFICANCE The novel nanofiber patterns developed in this study, via ENL, mimic the geometry and continuity of natural matrices found in the stroma of tissues, whilst preserving a quasi-2D character (to facilitate imaging and for comparison with other 2D systems such as micropatterned monolayers and circular nanopatches generated by colloidal lithography). These results demonstrate that the nanoscale geometry of the ECM plays an important role in regulating cell adhesion and that this is modulated by integrin expression. This is an important finding as it implies that the knowledge of the biochemical context underlying the integrin-mediated adhesive machinery of specific cell types should allow better design of biomaterials and biointerfaces. Indeed, changes in integrin expression are often associated with the control of cell proliferation and differentiation.
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Affiliation(s)
- Stefania Di Cio
- Institute of Bioengineering, Queen Mary, University of London, Mile End Road, London E1 4NS, UK; School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
| | - Thea M L Bøggild
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark
| | - John Connelly
- Institute of Bioengineering, Queen Mary, University of London, Mile End Road, London E1 4NS, UK; Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, 4 Newark Street, London E1 2AT, UK
| | | | - Julien E Gautrot
- Institute of Bioengineering, Queen Mary, University of London, Mile End Road, London E1 4NS, UK; School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London E1 4NS, UK.
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22
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23
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Kim W, Jung J. Polymer brush: a promising grafting approach to scaffolds for tissue engineering. BMB Rep 2017; 49:655-661. [PMID: 27697112 PMCID: PMC5346310 DOI: 10.5483/bmbrep.2016.49.12.166] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Indexed: 01/21/2023] Open
Abstract
Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate’s properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.
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Affiliation(s)
- Woonjung Kim
- Department of Chemistry, Hannam University, Daejeon 34054, Korea
| | - Jongjin Jung
- Department of Chemistry, Hannam University, Daejeon 34054, Korea
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24
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Tan KY, Ramstedt M, Colak B, Huck WTS, Gautrot JE. Study of thiol–ene chemistry on polymer brushes and application to surface patterning and protein adsorption. Polym Chem 2016. [DOI: 10.1039/c5py01687h] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The functionalisation and patterning of polymer brushes via thiol–ene chemistry is studied via ellipsometry, XPS and AFM.
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Affiliation(s)
- Khooi Y. Tan
- Melville Laboratory for Polymer Synthesis
- Department of Chemistry
- University of Cambridge
- Cambridge
- UK
| | | | - Burcu Colak
- Institute of Bioengineering
- Queen Mary
- University of London
- London
- UK
| | - Wilhelm T. S. Huck
- Radboud University Nijmegen
- Institute for Molecules and Materials
- 6525 AJ Nijmegen
- The Netherlands
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25
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Abstract
Tissue fusion eliminates physical voids in a tissue to form a continuous structure and is central to many processes in development and repair. Fusion events in vivo, particularly in embryonic development, often involve the purse-string contraction of a pluricellular actomyosin cable at the free edge. However, in vitro, adhesion of the cells to their substrate favors a closure mechanism mediated by lamellipodial protrusions, which has prevented a systematic study of the purse-string mechanism. Here, we show that monolayers can cover well-controlled mesoscopic nonadherent areas much larger than a cell size by purse-string closure and that active epithelial fluctuations are required for this process. We have formulated a simple stochastic model that includes purse-string contractility, tissue fluctuations, and effective friction to qualitatively and quantitatively account for the dynamics of closure. Our data suggest that, in vivo, tissue fusion adapts to the local environment by coordinating lamellipodial protrusions and purse-string contractions.
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26
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Appel EA, Larson BL, Luly KM, Kim JD, Langer R. Non-cell-adhesive substrates for printing of arrayed biomaterials. Adv Healthc Mater 2015; 4:501-5. [PMID: 25430948 PMCID: PMC4447497 DOI: 10.1002/adhm.201400594] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/04/2014] [Indexed: 01/07/2023]
Abstract
Cellular microarrays have become extremely useful in expediting the investigation of large libraries of (bio)materials for both in vitro and in vivo biomedical applications. An exceedingly simple strategy is developed for the fabrication of non-cell-adhesive substrates supporting the immobilization of diverse (bio)material features, including both monomeric and polymeric adhesion molecules (e.g., RGD and polylysine), hydrogels, and polymers.
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Affiliation(s)
- Eric A. Appel
- David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Benjamin L. Larson
- David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kathryn M. Luly
- David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinseong D. Kim
- David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert Langer
- David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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27
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Abstract
Mammalian skin research represents the convergence of three complementary disciplines: cell biology, mouse genetics, and dermatology. The skin provides a paradigm for current research in cell adhesion, inflammation, and tissue stem cells. Here, I discuss recent insights into the cell biology of skin. Single-cell analysis has revealed that human epidermal stem cells are heterogeneous and differentiate in response to multiple extrinsic signals. Live-cell imaging, optogenetics, and cell ablation experiments show skin cells to be remarkably dynamic. High-throughput, genome-wide approaches have yielded unprecedented insights into the circuitry that controls epidermal stem cell fate. Last, integrative biological analysis of human skin disorders has revealed unexpected functions for elements of the skin that were previously considered purely structural.
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Affiliation(s)
- Fiona M Watt
- King's College London Centre for Stem Cells and Regenerative Medicine, 28th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK.
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28
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Krishnamoorthy M, Hakobyan S, Ramstedt M, Gautrot JE. Surface-initiated polymer brushes in the biomedical field: applications in membrane science, biosensing, cell culture, regenerative medicine and antibacterial coatings. Chem Rev 2014; 114:10976-1026. [PMID: 25353708 DOI: 10.1021/cr500252u] [Citation(s) in RCA: 393] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Mahentha Krishnamoorthy
- Institute of Bioengineering and ‡School of Engineering and Materials Science, Queen Mary University of London , Mile End Road, London E1 4NS, United Kingdom
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29
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Moroni L, Klein Gunnewiek M, Benetti EM. Polymer brush coatings regulating cell behavior: passive interfaces turn into active. Acta Biomater 2014; 10:2367-78. [PMID: 24607856 DOI: 10.1016/j.actbio.2014.02.048] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/20/2014] [Accepted: 02/25/2014] [Indexed: 11/17/2022]
Abstract
Material technology platforms able to modulate the communication with cells at the interface of biomaterials are being increasingly experimented. Progress in the fabrication of supports is simultaneously introducing new surface modification strategies aimed at turning these supports from passive to active components in engineered preparations. Among these platforms, polymer brushes are arising not only as coatings determining the physical and (bio)chemical surface properties of biomaterials, but also as smart linkers between surfaces and biological cues. Their peculiar properties, especially when brushes are synthesized by "grafting-from" methods, enable closer mimicking of the complex and heterogeneous biological microenvironments. Inspired by the growing interest in this field of materials science, we summarize here the most prominent and recent advances in the synthesis of "grafted-from" polymer brush surfaces to modulate the response of adhering cells.
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Affiliation(s)
- Lorenzo Moroni
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands; Department of Complex Tissue Regeneration, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands
| | - Michel Klein Gunnewiek
- Department of Materials Science and Technology of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Edmondo M Benetti
- Department of Materials Science and Technology of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands; Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland.
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30
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Tan KY, Lin H, Ramstedt M, Watt FM, Huck WTS, Gautrot JE. Decoupling geometrical and chemical cues directing epidermal stem cell fate on polymer brush-based cell micro-patterns. Integr Biol (Camb) 2014; 5:899-910. [PMID: 23572192 DOI: 10.1039/c3ib40026c] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The intricacy of the different parameters involved in cell adhesion to biomaterials and fate decision (e.g. proliferation, differentiation, apoptosis) makes the decoupling of the respective effects of surface properties, extra-cellular matrix protein adsorption and ultimately cell behaviour difficult. This work presents a micro-patterned polymer brush platform to control the adsorption of extra-cellular matrix (ECM) proteins to well defined micron-size areas and consequently control cell adhesion, spreading and shape independently of other chemical and physical surface properties. Protein patterns can be readily generated with brushes presenting a range of hydrophilicity and surface charge density. The surface properties of the selected brushes are fully characterised using a combination of FTIR, XPS, ellipsometry, atomic force microscopy, water contact goniometry, dynamic light scattering and ζ-potential measurements. Interactions of proteins relevant to cell patterning and culture with these brushes are studied by surface plasmon resonance, dynamic light scattering, ellipsometry and immuno-fluorescence microscopy. Finally this platform is used in an assay investigating the relative contributions of matrix geometry and surface chemistry on epidermal stem cell differentiation. It is found that moderate hydrophobicity does not impact stem cell commitment, whereas strongly negative surface potential increases the incidence of differentiation. This correlates with a marked decrease in the formation of focal adhesions (but not cell spreading).
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Affiliation(s)
- Khooi Y Tan
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Cambridge, UK
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31
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Vedula SRK, Hirata H, Nai MH, Brugués A, Toyama Y, Trepat X, Lim CT, Ladoux B. Epithelial bridges maintain tissue integrity during collective cell migration. NATURE MATERIALS 2014; 13:87-96. [PMID: 24292420 DOI: 10.1038/nmat3814] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 10/17/2013] [Indexed: 05/22/2023]
Abstract
The ability of skin to act as a barrier is primarily determined by the efficiency of skin cells to maintain and restore its continuity and integrity. In fact, during wound healing keratinocytes migrate collectively to maintain their cohesion despite heterogeneities in the extracellular matrix. Here, we show that monolayers of human keratinocytes migrating along functionalized micropatterned surfaces comprising alternating strips of extracellular matrix (fibronectin) and non-adherent polymer form suspended multicellular bridges over the non-adherent areas. The bridges are held together by intercellular adhesion and are subjected to considerable tension, as indicated by the presence of prominent actin bundles. We also show that a model based on force propagation through an elastic material reproduces the main features of bridge maintenance and tension distribution. Our findings suggest that multicellular bridges maintain tissue integrity during wound healing when cell-substrate interactions are weak and may prove helpful in the design of artificial scaffolds for skin regeneration.
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Affiliation(s)
| | - Hiroaki Hirata
- Mechanobiology Institute, National University of Singapore, 117411, Singapore
| | - Mui Hoon Nai
- Mechanobiology Institute, National University of Singapore, 117411, Singapore
| | - Agustí Brugués
- Institut de Bioenginyeria de Catalunya (IBEC), ICREA, and Facultat de Medicina-Universitat de Barcelona, 08028 Barcelona, Spain
| | - Yusuke Toyama
- 1] Mechanobiology Institute, National University of Singapore, 117411, Singapore [2] Department of Biological Sciences, National University of Singapore and Temasek Life Sciences Laboratory, 117543, Singapore
| | - Xavier Trepat
- Institut de Bioenginyeria de Catalunya (IBEC), ICREA, and Facultat de Medicina-Universitat de Barcelona, 08028 Barcelona, Spain
| | - Chwee Teck Lim
- 1] Mechanobiology Institute, National University of Singapore, 117411, Singapore [2] Department of Biomedical Engineering and Department of Mechanical Engineering, National University of Singapore, 117576, Singapore
| | - Benoit Ladoux
- 1] Mechanobiology Institute, National University of Singapore, 117411, Singapore [2] Institut Jacques Monod (IJM), CNRS UMR 7592 and Université Paris Diderot, Paris 75013, France
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32
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Clement AL, Moutinho TJ, Pins GD. Micropatterned dermal-epidermal regeneration matrices create functional niches that enhance epidermal morphogenesis. Acta Biomater 2013; 9:9474-84. [PMID: 23958778 PMCID: PMC3818337 DOI: 10.1016/j.actbio.2013.08.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/01/2013] [Accepted: 08/09/2013] [Indexed: 11/18/2022]
Abstract
Although tissue engineered skin substitutes have demonstrated some clinical success for the treatment of chronic wounds such as diabetic and venous ulcers, persistent graft take and stability remain concerns. Current bilayered skin substitutes lack the characteristic microtopography of the dermal-epidermal junction that gives skin enhanced mechanical stability and creates cellular microniches that differentially promote keratinocyte function to form skin appendages and enhance wound healing. We developed a novel micropatterned dermal-epidermal regeneration matrix (μDERM) which incorporates this complex topography and substantially enhances epidermal morphology. Here, we describe the use of this three-dimensional (3-D) in vitro culture model to systematically evaluate different topographical geometries and to determine their relationship to keratinocyte function. We identified three distinct keratinocyte functional niches: the proliferative niche (narrow geometries), the basement membrane protein synthesis niche (wide geometries) and the putative keratinocyte stem cell niche (narrow geometries and corners). Specifically, epidermal thickness and keratinocyte proliferation is significantly (p<0.05) increased in 50 and 100 μm channels while laminin-332 deposition is significantly (p<0.05) increased in 400 μm channels compared to flat controls. Additionally, β1(bri)p63(+) keratinocytes, putative keratinocyte stem cells, preferentially cluster in channel geometries (similar to clustering observed in native skin) compared to a random distribution on flats. This study identifies specific target geometries to enhance skin regeneration and graft performance. Furthermore, these results suggest the importance of μDERM microtopography in designing the next generation of skin substitutes. Finally, we anticipate that 3-D organotypic cultures on μDERMS will provide a novel tissue engineered skin substitute for in vitro investigations of skin morphogenesis, wound healing and pathology.
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Affiliation(s)
- Amanda L. Clement
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
- Bioengineering Institute, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - Thomas J. Moutinho
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
- Bioengineering Institute, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - George D. Pins
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
- Bioengineering Institute, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
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33
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Rodriguez-Emmenegger C, Preuss CM, Yameen B, Pop-Georgievski O, Bachmann M, Mueller JO, Bruns M, Goldmann AS, Bastmeyer M, Barner-Kowollik C. Controlled cell adhesion on poly(dopamine) interfaces photopatterned with non-fouling brushes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:6123-7. [PMID: 23999835 DOI: 10.1002/adma.201302492] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/04/2013] [Indexed: 05/22/2023]
Abstract
Bioinspired poly(dopamine) (PDA) films are merged with antifouling poly(MeOEGMA) brushes utilizing a nitrile imine-mediated tetrazole-ene cycloaddition (NITEC)-based phototriggered surface encoding protocol. The antifouling brushes were photopatterned on PDA surfaces, leading cells to form confluent layers in the non-irradiated sections, while no adhesion occurred on the brushes resulting in a remarkably precise cell pattern. The presented strategy paves the way for the design of tailor-made patterned cell interfaces.
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Affiliation(s)
- Cesar Rodriguez-Emmenegger
- Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76131, Karlsruhe, Germany; Zell- und Neurobiologie, Zoologisches Institut, Karlsruhe Institute of Technology (KIT), Haid-und-Neu-Str. 9, Karlsruhe and Institut für Funktionelle Grenzflächen (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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34
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A bioengineered microenvironment to quantitatively measure the tumorigenic properties of cancer-associated fibroblasts in human prostate cancer. Biomaterials 2013; 34:4777-85. [DOI: 10.1016/j.biomaterials.2013.03.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/03/2013] [Indexed: 02/05/2023]
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