1
|
Wang Z, Dabaja R, Chen L, Banu M. Machine learning unifies flexibility and efficiency of spinodal structure generation for stochastic biomaterial design. Sci Rep 2023; 13:5414. [PMID: 37012266 PMCID: PMC10070414 DOI: 10.1038/s41598-023-31677-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/15/2023] [Indexed: 04/05/2023] Open
Abstract
Porous biomaterials design for bone repair is still largely limited to regular structures (e.g. rod-based lattices), due to their easy parameterization and high controllability. The capability of designing stochastic structure can redefine the boundary of our explorable structure-property space for synthesizing next-generation biomaterials. We hereby propose a convolutional neural network (CNN) approach for efficient generation and design of spinodal structure-an intriguing structure with stochastic yet interconnected, smooth, and constant pore channel conducive to bio-transport. Our CNN-based approach simultaneously possesses the tremendous flexibility of physics-based model in generating various spinodal structures (e.g. periodic, anisotropic, gradient, and arbitrarily large ones) and comparable computational efficiency to mathematical approximation model. We thus successfully design spinodal bone structures with target anisotropic elasticity via high-throughput screening, and directly generate large spinodal orthopedic implants with desired gradient porosity. This work significantly advances stochastic biomaterials development by offering an optimal solution to spinodal structure generation and design.
Collapse
Affiliation(s)
- Zhuo Wang
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Rana Dabaja
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lei Chen
- Department of Mechanical Engineering, University of Michigan-Dearborn, Dearborn, MI, 48128, USA.
| | - Mihaela Banu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
2
|
Vanoli V, Massobrio G, Pizzetti F, Mele A, Rossi F, Castiglione F. Bijels as a Fluid Labyrinth for Drugs: The Effect of Nanoparticles on the Release Kinetics of Ethosuximide and Dimethyl Fumarate. ACS OMEGA 2022; 7:42845-42853. [PMID: 36467913 PMCID: PMC9713867 DOI: 10.1021/acsomega.2c04834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Bijels (bicontinuous interfacially jammed emulsion gels) raised an increasing interest as biomaterials for controlled drug delivery due to their biphasic nature organized in mesoscopic tortuous domains. Two bijel formulations were prepared and explored as delivery systems for both hydrophilic and lipophilic drugs, ethosuximide and dimethyl fumarate. The two bijel-like structures, based on polymerized ε-caprolactone/water, differ in the stabilizing nanoparticle hydroxyapatite (inorganic) and nanogel-based nanoparticles (organic). Diffusion nuclear magnetic resonance spectroscopy has been used to characterize the bijel structure and the transport behavior of the drug molecules confined within the water/organic interconnected domains. A reduced diffusion coefficient is observed for several concentrations of the drugs and both bijel formulations. Moreover, in vitro release profiles also reveal the effect of the microstructure and drug-nanoparticle interactions.
Collapse
Affiliation(s)
- Valeria Vanoli
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
| | - Giovanna Massobrio
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
| | - Fabio Pizzetti
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
| | - Andrea Mele
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
- CNR
Istituto di Chimica del Riconoscimento Molecolare, Via Mancinelli 7, 20131Milan, Italy
| | - Filippo Rossi
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
| | - Franca Castiglione
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. Da Vinci, 32, 20133Milano, Italy
| |
Collapse
|
3
|
Romano G, Almeida M, Varela Coelho A, Cutignano A, Gonçalves LG, Hansen E, Khnykin D, Mass T, Ramšak A, Rocha MS, Silva TH, Sugni M, Ballarin L, Genevière AM. Biomaterials and Bioactive Natural Products from Marine Invertebrates: From Basic Research to Innovative Applications. Mar Drugs 2022; 20:md20040219. [PMID: 35447892 PMCID: PMC9027906 DOI: 10.3390/md20040219] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/16/2022] [Accepted: 03/16/2022] [Indexed: 12/22/2022] Open
Abstract
Aquatic invertebrates are a major source of biomaterials and bioactive natural products that can find applications as pharmaceutics, nutraceutics, cosmetics, antibiotics, antifouling products and biomaterials. Symbiotic microorganisms are often the real producers of many secondary metabolites initially isolated from marine invertebrates; however, a certain number of them are actually synthesized by the macro-organisms. In this review, we analysed the literature of the years 2010–2019 on natural products (bioactive molecules and biomaterials) from the main phyla of marine invertebrates explored so far, including sponges, cnidarians, molluscs, echinoderms and ascidians, and present relevant examples of natural products of interest to public and private stakeholders. We also describe omics tools that have been more relevant in identifying and understanding mechanisms and processes underlying the biosynthesis of secondary metabolites in marine invertebrates. Since there is increasing attention on finding new solutions for a sustainable large-scale supply of bioactive compounds, we propose that a possible improvement in the biodiscovery pipeline might also come from the study and utilization of aquatic invertebrate stem cells.
Collapse
Affiliation(s)
- Giovanna Romano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
- Correspondence: (G.R.); (L.B.)
| | - Mariana Almeida
- 3B’s Research Group, I3B’s—Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark—Parque de Ciência e Tecnologia, Barco, 4805-017 Guimarães, Portugal; (M.A.); (M.S.R.); (T.H.S.)
- ICVS/3B´s—PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Ana Varela Coelho
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (A.V.C.); (L.G.G.)
| | - Adele Cutignano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
- CNR-Institute of Biomolecular Chemistry, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Luis G Gonçalves
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (A.V.C.); (L.G.G.)
| | - Espen Hansen
- Marbio, UiT-The Arctic University of Norway, 9037 Tromso, Norway;
| | - Denis Khnykin
- Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Department of Pathology, Oslo University Hospital-Rikshospitalet, 0450 Oslo, Norway;
| | - Tali Mass
- Faculty of Natural Science, Department of Marine Biology, Charney School of Marine Sciences, University of Haifa, Haifa 3498838, Israel;
| | - Andreja Ramšak
- National Institute of Biology, Marine Biology Station, Fornače 41, SI-6330 Piran, Slovenia;
| | - Miguel S. Rocha
- 3B’s Research Group, I3B’s—Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark—Parque de Ciência e Tecnologia, Barco, 4805-017 Guimarães, Portugal; (M.A.); (M.S.R.); (T.H.S.)
- ICVS/3B´s—PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Tiago H. Silva
- 3B’s Research Group, I3B’s—Research Institute on Biomaterials, Biodegradables and Biomimetics of University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark—Parque de Ciência e Tecnologia, Barco, 4805-017 Guimarães, Portugal; (M.A.); (M.S.R.); (T.H.S.)
- ICVS/3B´s—PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Michela Sugni
- Department of Environmental Science and Policy, University of Milan, Via Celoria, 2, 20133 Milan, Italy;
| | - Loriano Ballarin
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35100 Padova, Italy
- Correspondence: (G.R.); (L.B.)
| | - Anne-Marie Genevière
- Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique de Banyuls-sur-Mer, Sorbonne Université, CNRS, 1 Avenue Pierre Fabre, 66650 Banyuls-sur-Mer, France;
| |
Collapse
|
4
|
Benayahu D, Benayahu Y. A Unique Marine-Derived Collagen: Its Characterization towards Biocompatibility Applications for Tissue Regeneration. Mar Drugs 2021; 19:md19080419. [PMID: 34436257 PMCID: PMC8397963 DOI: 10.3390/md19080419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 01/05/2023] Open
Abstract
Biomedical engineering combines engineering and materials methods to restore, maintain, improve, or replace different types of biological tissues. In tissue engineering, following major injury, a scaffold is designed to support the local growth of cells, enabling the development of new viable tissue. To provide the conditions for the mechanical and structural properties needed for the restored tissue and its appropriate functioning, the scaffold requires specific biochemical properties in order to ensure a correct healing process. The scaffold creates a support system and requires a suitable material that will transduce the appropriate signals for the regenerative process to take place. A scaffold composed of material that mimics natural tissue, rather than a synthetic material, will achieve better results. Here, we provide an overview of natural components of marine-derived origin, the collagen fibers characterization schematic is summarized in the graphical abstract. The use of collagen fibers for biomedical applications and their performances in cell support are demonstrated in an in vitro system and in tissue regeneration in vivo.
Collapse
Affiliation(s)
- Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Correspondence:
| | - Yehuda Benayahu
- School of Zoology, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv 6997801, Israel;
| |
Collapse
|
5
|
Pomeraniec L, Benayahu D. Mesenchymal Cell Growth and Differentiation on a New Biocomposite Material: A Promising Model for Regeneration Therapy. Biomolecules 2020; 10:biom10030458. [PMID: 32188110 PMCID: PMC7175166 DOI: 10.3390/biom10030458] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 01/13/2023] Open
Abstract
Mesenchymal stem cells serve as the body’s reservoir for healing and tissue regeneration. In cases of severe tissue trauma where there is also a need for tissue organization, a scaffold may be of use to support the cells in the damaged tissue. Such a scaffold should be composed of a material that can biomimic the mechanical and biological properties of the target tissues in order to support autologous cell-adhesion, their proliferation, and differentiation. In this study, we developed and assayed a new biocomposite made of unique collagen fibers and alginate hydrogel that was assessed for the ability to support mesenchymal cell-proliferation and differentiation. Analysis over 11 weeks in vitro demonstrated that the scaffold was biocompatible and supports the cells viability and differentiation to produce tissue-like structures or become adipocyte under differentiation medium. When the biocomposite was enriched with nano particles (NPs), mesenchymal cells grew well after uptake of fluorescein isothiocyanate (FITC) labeled NPs, maintained their viability, migrated through the biocomposite, reached, and adhered to the tissue culture dish. These promising findings revealed that the scaffold supports the growth and differentiation of mesenchymal cells that demonstrate their full physiological function with no sign of material toxicity. The cells’ functionality performance indicates and suggests that the scaffold is suitable to be developed as a new medical device that has the potential to support regeneration and the production of functional tissue.
Collapse
|
6
|
Gould EM, Macmillan KA, Clegg PS. Autonomous analysis to identify bijels from two-dimensional images. SOFT MATTER 2020; 16:2565-2573. [PMID: 32083271 DOI: 10.1039/c9sm02187f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bicontinuous interfacially jammed emulsion gels (bijels) are novel composite materials that can be challenging to manufacture. As a step towards automating production, we have developed a machine learning tool to classify fabrication attempts. We use training and testing data in the form of confocal images from both successful and unsuccessful attempts at bijel fabrication. We then apply machine learning techniques to this data in order to classify whether an image is a bijel or a non-bijel. Our principal approach is to process the images to find their autocorrelation function and structure factor, and from these functions we identify variables that can be used for training a supervised machine learning model to identify a bijel image. We are able to categorise images with reasonable accuracies of 85.4% and 87.5% for two different approaches. We find that using both the liquid and particle channels helps to achieve optimal performance and that successful classification relies on the bijel samples sharing a characteristic length scale. Our second approach is to classify the shapes of the liquid domains directly; the shape descriptors are then used to classify fabrication attempts via a decision tree. We have used an adaptive design approach to find an image pre-processing step that yields the optimal classification results. Again, we find that the characteristic length scale of the images is crucial in performing the classification.
Collapse
Affiliation(s)
- Emily M Gould
- School of Physics and Astronomy, University of Edinburgh, James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK.
| | | | | |
Collapse
|
7
|
Wang J, Le-The H, Wang Z, Li H, Jin M, van den Berg A, Zhou G, Segerink LI, Shui L, Eijkel JCT. Microfluidics Assisted Fabrication of Three-Tier Hierarchical Microparticles for Constructing Bioinspired Surfaces. ACS NANO 2019; 13:3638-3648. [PMID: 30856322 DOI: 10.1021/acsnano.9b00245] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Construction of textured bioinspired surfaces with refined structures that exhibit superior wetting properties is of great importance for many applications ranging from self-cleaning, antibiofouling, anti-icing, oil/water separation, smart membrane, and microfluidic devices. Previously, the preparation of artificial surfaces generally relies on the combination of different approaches together, which is a lack of flexibility to control over the individual architecture unit, the surface topology, as well as the complex procedure needed. In this work, we report a method for rapid fabrication of three-tier hierarchical microunits (structures consisting of multiple levels) using a facile droplet microfluidics approach. These units include the first-tier microspheres consisting of the second-tier close-packed polystyrene (PS) nanoparticles decorated with the third-tier elegant polymer nanowrinkles. These nanowrinkles on the PS nanoparticles are formed according to the interfacial instability induced by gradient photopolymerization of N-isopropylacrylamide (NIPAM) monomers. The formation process and topologies of nanowrinkles can be regulated by the photopolymerization process and the fraction of carboxylic groups on the PS nanoparticle surface. Such a hierarchical microsphere mimics individual units of bioinspired surfaces. Therefore, the surfaces from self-assembly of these fabricated two-tier and three-tier hierarchical microunits collectively exhibit "gecko" and "rose petal" wetting states, with the micro- and nanoscale structures amplifying the initial hydrophobicity but still being highly adhesive to water. This approach offers promising advantages of high-yield fabrication, precise control over the size and component of the microspheres, and integration of microfluidic droplet generation, colloidal nanoparticle self-assembly, and interfacial polymerization-induced nanowrinkles in a straightforward manner.
Collapse
Affiliation(s)
- Juan Wang
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Hai Le-The
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Zuankai Wang
- Department of Mechanical and Biomedical Engineering , City University of Hong Kong , Hong Kong 999077 , China
| | - Hao Li
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Mingliang Jin
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Albert van den Berg
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Guofu Zhou
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Loes I Segerink
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| | - Lingling Shui
- National Center for International Research on Green Optoelectronics and South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
- School of Information and Optoelectronic Science and Engineering , South China Normal University , Guangzhou 510006 , China
| | - Jan C T Eijkel
- BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Technical Medical Centre and Max Planck Center for Complex Fluid Dynamics , University of Twente , Enschede 7522NB , The Netherlands
| |
Collapse
|
8
|
Deng S, Wang Y, Zhuang G, Zhong X, Wei Z, Yao Z, Wang JG. Micromechanical simulation of the pore size effect on the structural stability of brittle porous materials with bicontinuous morphology. Phys Chem Chem Phys 2019; 21:12895-12904. [DOI: 10.1039/c9cp01582e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A part of the solid phase in bicontinuous structures sustains the deformation and larger pore sizes result in lower Young's moduli.
Collapse
Affiliation(s)
- Shengwei Deng
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Yinbin Wang
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Guilin Zhuang
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Xing Zhong
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Zhongzhe Wei
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Zihao Yao
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| | - Jian-guo Wang
- Institute of Industrial Catalysis
- College of Chemical Engineering
- State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology
- Zhejiang University of Technology
- Hangzhou 310032
| |
Collapse
|
9
|
San Lim H, Lee SY, Lee NE, Cho SO. Patterning of Wrinkled Polymer Surfaces by Single-Step Electron Irradiation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5290-5296. [PMID: 29652508 DOI: 10.1021/acs.langmuir.8b00403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A novel yet simple approach to fabricate and pattern wrinkled surfaces on polymers is presented. Only by irradiating an electron beam onto a polymer, wrinkles are created on the polymer surface. Electron irradiation produces a bilayer polymeric structure comprising a degrading upper layer and a pristine bottom layer. Electron irradiation also increases the polymer surface temperature to a point much higher than the glass-transition temperature of the upper layer, leading to drastic thermal expansion of the upper layer. As a result, significant compressive force is applied to form surface wrinkles. The mechanism behind the wrinkle formation and the effects of electron irradiation parameters on the wrinkle characteristics are discussed. In addition, by this electron irradiation approach, a patterned wrinkle structure is uniquely prepared.
Collapse
Affiliation(s)
- Hyung San Lim
- Department of Nuclear and Quantum Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 373-1 Guseong , Yuseong, Daejeon 305-701 , Republic of Korea
| | - Sang Yoon Lee
- Department of Nuclear and Quantum Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 373-1 Guseong , Yuseong, Daejeon 305-701 , Republic of Korea
| | - Na Eun Lee
- Department of Nuclear and Quantum Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 373-1 Guseong , Yuseong, Daejeon 305-701 , Republic of Korea
| | - Sung Oh Cho
- Department of Nuclear and Quantum Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 373-1 Guseong , Yuseong, Daejeon 305-701 , Republic of Korea
| |
Collapse
|
10
|
Benayahu D, Sharabi M, Pomeraniec L, Awad L, Haj-Ali R, Benayahu Y. Unique Collagen Fibers for Biomedical Applications. Mar Drugs 2018; 16:md16040102. [PMID: 29570651 PMCID: PMC5923389 DOI: 10.3390/md16040102] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/09/2018] [Accepted: 03/17/2018] [Indexed: 12/14/2022] Open
Abstract
The challenge to develop grafts for tissue regeneration lies in the need to obtain a scaffold that will promote cell growth in order to form new tissue at a trauma-damaged site. Scaffolds also need to provide compatible mechanical properties that will support the new tissue and facilitate the desired physiological activity. Here, we used natural materials to develop a bio-composite made of unique collagen embedded in an alginate hydrogel material. The collagen fibers used to create the building blocks exhibited a unique hyper-elastic behavior similar to that of natural human tissue. The prominent mechanical properties, along with the support of cell adhesion affects cell shape and supports their proliferation, consequently facilitating the formation of a new tissue-like structure. The current study elaborates on these unique collagen fibers, focusing on their structure and biocompatibility, in an in vitro model. The findings suggest it as a highly appropriate material for biomedical applications. The promising in vitro results indicate that the distinctive collagen fibers could serve as a scaffold that can be adapted for tissue regeneration, in support of healing processes, along with maintaining tissue mechanical properties for the new regenerate tissue formation.
Collapse
Affiliation(s)
- Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Mirit Sharabi
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Leslie Pomeraniec
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Lama Awad
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Rami Haj-Ali
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Yehuda Benayahu
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| |
Collapse
|
11
|
Thijssen JHJ, Vermant J. Interfacial rheology of model particles at liquid interfaces and its relation to (bicontinuous) Pickering emulsions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:023002. [PMID: 29165321 DOI: 10.1088/1361-648x/aa9c74] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Interface-dominated materials are commonly encountered in both science and technology, and typical examples include foams and emulsions. Conventionally stabilised by surfactants, emulsions can also be stabilised by micron-sized particles. These so-called Pickering-Ramsden (PR) emulsions have received substantial interest, as they are model arrested systems, rather ubiquitous in industry and promising templates for advanced materials. The mechanical properties of the particle-laden liquid-liquid interface, probed via interfacial rheology, have been shown to play an important role in the formation and stability of PR emulsions. However, the morphological processes which control the formation of emulsions and foams in mixing devices, such as deformation, break-up, and coalescence, are complex and diverse, making it difficult to identify the precise role of the interfacial rheological properties. Interestingly, the role of interfacial rheology in the stability of bicontinuous PR emulsions (bijels) has been virtually unexplored, even though the phase separation process which leads to the formation of these systems is relatively simple and the interfacial deformation processes can be better conceptualised. Hence, the aims of this topical review are twofold. First, we review the existing literature on the interfacial rheology of particle-laden liquid interfaces in rheometrical flows, focussing mainly on model latex suspensions consisting of polystyrene particles carrying sulfate groups, which have been most extensively studied to date. The goal of this part of the review is to identify the generic features of the rheology of such systems. Secondly, we will discuss the relevance of these results to the formation and stability of PR emulsions and bijels.
Collapse
Affiliation(s)
- J H J Thijssen
- SUPA School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kindom
| | | |
Collapse
|
12
|
Shen L, Lafleur SSD, Houben SJA, Murphy JN, Severn JR, Bastiaansen CWM. Surface Micropatterning of Uniaxially Oriented Polyethylene Films Using Interference Holography for Strain Sensors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14592-14598. [PMID: 29207247 PMCID: PMC6150734 DOI: 10.1021/acs.langmuir.7b03599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/05/2017] [Indexed: 06/07/2023]
Abstract
A new procedure is presented for direct generation of surface micropatterns on uniaxially oriented polyethylene (PE) films using interference holography with a nanosecond pulsed laser. An ultraviolet absorber, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (BZT) is incorporated into PE prior to stretching to generate absorption at the wavelength of the laser. Illumination with an interference pattern in the absorption band of BZT leads to an obvious height variation in the exposed regions and consequently relief gratings are generated. The height in the exposed regions is strongly dependent on the angle between the grating direction and the film orientation direction. This phenomenon is attributed to a combination of events such as melting, entropic contraction, recrystallization, thermal evaporation of BZT, and anisotropic thermal conductivity. It is shown that the relief height increases with increasing BZT concentration and exhibits a linear dependence on the energy dose above a certain threshold. Additionally, the oriented PE films with the surface micropatterns are explored for strain sensors. The results demonstrate that small strains below 10% are monitored accurately in tensile deformation of the micropatterned, oriented PE films which makes these films potentially useful as strain sensors.
Collapse
Affiliation(s)
- Lihua Shen
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Sarah S. D. Lafleur
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Simon J. A. Houben
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Jeffrey N. Murphy
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - John R. Severn
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- DSM
Materials Science Center, NL-6160 MD Geleen, The Netherlands
| | - Cees W. M. Bastiaansen
- Laboratory
of Functional Organic Materials and Devices, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- School
of Engineering and Materials Science, Queen
Mary University of London, London E1 4NS, U.K.
| |
Collapse
|
13
|
Blowes LM, Egertová M, Liu Y, Davis GR, Terrill NJ, Gupta HS, Elphick MR. Body wall structure in the starfish Asterias rubens. J Anat 2017; 231:325-341. [PMID: 28714118 PMCID: PMC5554833 DOI: 10.1111/joa.12646] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2017] [Indexed: 12/25/2022] Open
Abstract
The body wall of starfish is composed of magnesium calcite ossicles connected by collagenous tissue and muscles and it exhibits remarkable variability in stiffness, which is attributed to the mechanical mutability of the collagenous component. Using the common European starfish Asterias rubens as an experimental animal, here we have employed a variety of techniques to gain new insights into the structure of the starfish body wall. The structure and organisation of muscular and collagenous components of the body wall were analysed using trichrome staining. The muscle system comprises interossicular muscles as well as muscle strands that connect ossicles with the circular muscle layer of the coelomic lining. The collagenous tissue surrounding the ossicle network contains collagen fibres that form loop-shaped straps that wrap around calcite struts near to the surface of ossicles. The 3D architecture of the calcareous endoskeleton was visualised for the first time using X-ray microtomography, revealing the shapes and interactions of different ossicle types. Furthermore, analysis of the anatomical organisation of the ossicles indicates how changes in body shape may be achieved by local contraction/relaxation of interossicular muscles. Scanning synchrotron small-angle X-ray diffraction (SAXD) scans of the starfish aboral body wall and ambulacrum were used to study the collagenous tissue component at the fibrillar level. Collagen fibrils in aboral body wall were found to exhibit variable degrees of alignment, with high levels of alignment probably corresponding to regions where collagenous tissue is under tension. Collagen fibrils in the ambulacrum had a uniformly low degree of orientation, attributed to macrocrimp of the fibrils and the presence of slanted as well as horizontal fibrils connecting antimeric ambulacral ossicles. Body wall collagen fibril D-period lengths were similar to previously reported mammalian D-periods, but were significantly different between the aboral and ambulacral samples. The overlap/D-period length ratio within fibrils was higher than reported for mammalian tissues. Collectively, the data reported here provide new insights into the anatomy of the body wall in A. rubens and a foundation for further studies investigating the structural basis of the mechanical properties of echinoderm body wall tissue composites.
Collapse
Affiliation(s)
- Liisa M Blowes
- School of Biological & Chemical Sciences, Queen Mary University of London, London, UK.,School of Engineering & Materials Science, Queen Mary University of London, London, UK
| | - Michaela Egertová
- School of Biological & Chemical Sciences, Queen Mary University of London, London, UK
| | - Yankai Liu
- School of Engineering & Materials Science, Queen Mary University of London, London, UK
| | - Graham R Davis
- Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | | | - Himadri S Gupta
- School of Engineering & Materials Science, Queen Mary University of London, London, UK
| | - Maurice R Elphick
- School of Biological & Chemical Sciences, Queen Mary University of London, London, UK
| |
Collapse
|
14
|
Reeves M, Stratford K, Thijssen JHJ. Quantitative morphological characterization of bicontinuous Pickering emulsions via interfacial curvatures. SOFT MATTER 2016; 12:4082-4092. [PMID: 27035101 DOI: 10.1039/c5sm03102h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Bicontinuous Pickering emulsions (bijels) are a physically interesting class of soft materials with many potential applications including catalysis, microfluidics and tissue engineering. They are created by arresting the spinodal decomposition of a partially-miscible liquid with a (jammed) layer of interfacial colloids. Porosity L (average interfacial separation) of the bijel is controlled by varying the radius (r) and volume fraction (ϕ) of the colloids (L∝r/ϕ). However, to optimize the bijel structure with respect to other parameters, e.g. quench rate, characterizing by L alone is insufficient. Hence, we have used confocal microscopy and X-ray CT to characterize a range of bijels in terms of local and area-averaged interfacial curvatures; we further demonstrate that bijels are bicontinuous using an image-analysis technique known as 'region growing'. In addition, the curvatures of bijels have been monitored as a function of time, which has revealed an intriguing evolution up to 60 minutes after bijel formation, contrary to previous understanding.
Collapse
Affiliation(s)
- Matthew Reeves
- SUPA School of Physics and Astronomy, James Clerk Maxwell Building, Peter Guthrie Tait Road, King's Buildings, Edinburgh, EH9 3FD, UK.
| | | | | |
Collapse
|
15
|
Reeves M, Brown AT, Schofield AB, Cates ME, Thijssen JHJ. Particle-size effects in the formation of bicontinuous Pickering emulsions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:032308. [PMID: 26465474 DOI: 10.1103/physreve.92.032308] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate that the formation of bicontinuous emulsions stabilized by interfacial particles (bijels) is more robust when nanoparticles rather than microparticles are used. Emulsification via spinodal demixing in the presence of nearly neutrally wetting particles is induced by rapid heating. Using confocal microscopy, we show that nanospheres allow successful bijel formation at heating rates two orders of magnitude slower than is possible with microspheres. In order to explain our results, we introduce the concept of mechanical leeway, i.e., nanoparticles benefit from a smaller driving force towards disruptive curvature. Finally, we suggest that leeway mechanisms may benefit any formulation in which challenges arise due to tight restrictions on a pivotal parameter, but where the restrictions can be relaxed by rationally changing the value of a more accessible parameter.
Collapse
Affiliation(s)
- M Reeves
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
| | - A T Brown
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
| | - A B Schofield
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
| | - M E Cates
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
| | - J H J Thijssen
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD, United Kingdom
| |
Collapse
|
16
|
Bai L, Fruehwirth JW, Cheng X, Macosko CW. Dynamics and rheology of nonpolar bijels. SOFT MATTER 2015; 11:5282-93. [PMID: 26053792 DOI: 10.1039/c5sm00994d] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Bicontinuous, interfacially jammed, emulsion gels (bijels) are a novel class of materials composed of two immiscible phases with interpenetrating domains that are stabilized by a monolayer of colloidal particles at the interface. However, existing bijel systems so far all consist of at least one polar fluid, which is believed to be essential to induce electrostatic repulsion for stabilizing interfacial particles. It is not known whether two nonpolar fluids can form a bijel. Here, we experimentally achieve a bijel using styrene trimer and low molecular weight polybutene-two nonpolar fluids that are similar to polymer blends, which are important in technical applications. By combining laser scanning confocal microscopy, cryo-SEM and rheology measurement, we systematically investigate the dynamics and rheology of this nonpolar bijel. In contrast to previous studies on polar bijels, we observe the formation of localized regions of high particle concentration or "particle patches" on the interface which assemble during coarsening. We also provide the first quantitative relation between the morphology of a bijel, the interfacial particle coverage and the shear modulus during bijel coarsening. Moreover, we reveal a previously unnoticed increase in the elastic modulus of bijels that can be attributed to the rearrangement of interfacial particles at long time scales. In addition, we also found a hydrophobic particle framework that survives after the direct remixing of the nonpolar bijel. Our study provides important insights into the formation of bijels and is the first step to explore the missing link between polar bijels and particle-stabilized bicontinuous polymer blends.
Collapse
Affiliation(s)
- Lian Bai
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
| | | | | | | |
Collapse
|
17
|
Cai D, Clegg PS. Stabilizing bijels using a mixture of fumed silica nanoparticles. Chem Commun (Camb) 2015; 51:16984-7. [DOI: 10.1039/c5cc07346d] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We demonstrate the fabrication of bicontinuous pickering emulsions (bijels) using “off the shelf” particles.
Collapse
Affiliation(s)
- Dongyu Cai
- School of Physics and Astronomy
- University of Edinburgh
- Edinburgh
- UK
| | - Paul S. Clegg
- School of Physics and Astronomy
- University of Edinburgh
- Edinburgh
- UK
| |
Collapse
|
18
|
Aina V, Magistris C, Cerrato G, Martra G, Viscardi G, Lusvardi G, Malavasi G, Menabue L. New formulation of functionalized bioactive glasses to be used as carriers for the development of pH-stimuli responsive biomaterials for bone diseases. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4703-4715. [PMID: 24701982 DOI: 10.1021/la5003989] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aim of the present contribution is to prepare a functionalized bioactive glass potentially useful as prosthetic material, but also able to release organic molecules in response to a change of the pH environment. By this approach it is possible to develop devices which can be used for a triggered drug release in response to specific stimuli; this is an attractive research field, in order to avoid either systemic and/or local toxic effects of drugs. In particular, in the present paper we report data related to the development of a new formulation of bioactive glasses, their functionalization with organic molecules to obtain a pH-sensitive bond, their physicochemical characterization and in vitro bioactivity in simulated biological fluids (SBF), and organic molecule delivery tests at different pH. The glass functionalization, by means of a covalent reaction, allows us to produce a model of pH-responsive bioactive biomaterial: when it is exposed to specific pH changes, it can favor the release of the organic molecules directly at the target site. Cysteamine and 5-aminofluorescein are used as model molecules to simulate a drug. The materials, before and after the different functionalization steps and in vitro release tests at different pH, have been characterized by means of different experimental techniques such as X-ray powder diffraction (XRPD), Raman, FTIR and fluorescence spectroscopies, N2 adsorption, thermogravimetric (TGA) and elemental analysis.
Collapse
Affiliation(s)
- Valentina Aina
- Department of Chemistry, Interdepartmental Centre Nanostructured Interfaces and Surfaces - NIS; INSTM (Italian National Consortium for Materials Science and Technology), University of Torino , Via P. Giuria 7, 10125 Torino, Italy
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Qian J, Xu W, Yong X, Jin X, Zhang W. Fabrication and in vitro biocompatibility of biomorphic PLGA/nHA composite scaffolds for bone tissue engineering. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 36:95-101. [DOI: 10.1016/j.msec.2013.11.047] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/30/2013] [Accepted: 11/29/2013] [Indexed: 12/31/2022]
|
20
|
Ben-Nissan B, Green DW. Marine Structures as Templates for Biomaterials. SPRINGER SERIES IN BIOMATERIALS SCIENCE AND ENGINEERING 2014. [DOI: 10.1007/978-3-642-53980-0_13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
21
|
Wen Z, Zhang L, Chen C, Liu Y, Wu C, Dai C. A construction of novel iron-foam-based calcium phosphate/chitosan coating biodegradable scaffold material. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2013; 33:1022-31. [DOI: 10.1016/j.msec.2012.10.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 09/01/2012] [Accepted: 10/26/2012] [Indexed: 11/15/2022]
|
22
|
Seif-Naraghi SB, Horn D, Schup-Magoffin PJ, Christman KL. Injectable extracellular matrix derived hydrogel provides a platform for enhanced retention and delivery of a heparin-binding growth factor. Acta Biomater 2012; 8:3695-703. [PMID: 22750737 DOI: 10.1016/j.actbio.2012.06.030] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 05/18/2012] [Accepted: 06/20/2012] [Indexed: 01/09/2023]
Abstract
Injectable hydrogels derived from the extracellular matrix (ECM) of decellularized tissues have recently emerged as scaffolds for tissue-engineering applications. Here, we introduce the potential for using a decellularized ECM-derived hydrogel for the improved delivery of heparin-binding growth factors. Immobilization of growth factors on a scaffold has been shown to increase their stability and activity. This can be done via chemical crosslinking, covalent bonding, or by incorporating natural or synthetic growth factor-binding domains similar to those found in vivo in sulfated glycosaminoglycans (GAGs). Many decellularized ECM-derived hydrogels retain native sulfated GAGs, and these materials may therefore provide an excellent delivery platform for heparin-binding growth factors. In this study, the sulfated GAG content of an ECM hydrogel derived from decellularized pericardial ECM was confirmed by Fourier transform infrared spectroscopy and its ability to bind basic fibroblast growth factor (bFGF) was established. Delivery in the pericardial matrix hydrogel increased retention of bFGF both in vitro and in vivo in ischemic myocardium compared to delivery in collagen. In a rodent infarct model, intramyocardial injection of bFGF in pericardial matrix enhanced neovascularization by approximately 112% compared to delivery in collagen. Importantly, the newly formed vasculature was anastomosed with existing vasculature. Thus, the sulfated GAG content of the decellularized ECM hydrogel provides a platform for incorporation of heparin-binding growth factors for prolonged retention and delivery.
Collapse
|
23
|
Mohan BG, Shenoy SJ, Babu SS, Varma HK, John A. Strontium calcium phosphate for the repair of leporine (Oryctolagus cuniculus) ulna segmental defect. J Biomed Mater Res A 2012; 101:261-71. [DOI: 10.1002/jbm.a.34324] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/19/2012] [Accepted: 06/20/2012] [Indexed: 11/11/2022]
|
24
|
Huang C, Tang Z, Zhou Y, Zhou X, Jin Y, Li D, Yang Y, Zhou S. Magnetic micelles as a potential platform for dual targeted drug delivery in cancer therapy. Int J Pharm 2012; 429:113-22. [DOI: 10.1016/j.ijpharm.2012.03.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 03/03/2012] [Accepted: 03/04/2012] [Indexed: 10/28/2022]
|
25
|
Looney M, Shea HO, Gunn L, Crowley D, Boyd D. An evaluation of the processing conditions, structure, and properties (biaxial flexural strength and antibacterial efficacy) of sintered strontium–zinc–silicate glass ceramics. J Biomater Appl 2011; 27:937-47. [DOI: 10.1177/0885328211430423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of artificial bone grafts has increased in order to satisfy a growing demand for bone replacement materials. Initial mechanical stability of synthetic bone grafts is very advantageous for certain clinical applications. Coupled with the advantage of mechanical strength, a material with inherent antibacterial properties would be very beneficial. A series of strontium-doped zinc silicate (Ca–Sr–Na–Zn–Si) glass ceramics have been characterized in terms of their crystalline structure, biaxial flexural strength and antibacterial efficacy based on the identification of optimum sintering conditions. All three glass ceramics, namely, BT110, BT111, and BT112 were found to be fully crystalline, with BT111 and BT112 comprising of biocompatible crystalline phases. The biaxial flexural strengths of the three glass ceramics ranged from 70 to 149 MPa and were shown to be superior to those of clinically established ceramics in dry conditions and following incubation in simulated physiological conditions. The bacteriostatic effect for each glass ceramic was also established, where BT112 showed an inhibitory effect against three of the most common bacteria found at implantation sites, namely, Enterococcus faecalis, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. The results of the evaluation suggest that the materials studied offer advantages over current clinical materials and indicate the potential suitability of the glass ceramics as therapeutic bone grafts.
Collapse
Affiliation(s)
- Mark Looney
- Medical Engineering Design and Innovation Centre, Cork Institute of Technology, Ireland
| | - Helen O' Shea
- Department of Biological Sciences, Cork Institute of Technology, Ireland
| | - Lynda Gunn
- Department of Biological Sciences, Cork Institute of Technology, Ireland
| | - Dolores Crowley
- Department of Biological Sciences, Cork Institute of Technology, Ireland
| | - Daniel Boyd
- Department of Applied Oral Sciences, Dalhousie University, Halifax, B3H 4R2, Canada
| |
Collapse
|
26
|
Designs from the deep: Marine organisms for bone tissue engineering. Biotechnol Adv 2011; 29:610-7. [DOI: 10.1016/j.biotechadv.2011.04.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/12/2011] [Indexed: 12/21/2022]
|
27
|
Looney M, O’Shea H, Boyd D. Preliminary evaluation of therapeutic ion release from Sr-doped zinc-silicate glass ceramics. J Biomater Appl 2011; 27:511-24. [DOI: 10.1177/0885328211413621] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bioactive and degradable porous bioceramics play an important role in many clinical situations. Porosity is essential to the performance of a material that is proposed to be used as an implantable osseous scaffold. Scaffolds provide a three dimensional support and template to osseous integration and vascularization. Combining the porosity of a scaffold with the ability of the scaffold material to deliver therapeutic ions to the site of implantation goes some way towards developing an ideal bone graft. A series of strontium-doped zinc silicate (Ca-Sr-Na-Zn-Si) glass ceramics scaffoldswere developed, whose porosity was measured to be between 93% and 96%, which is advantageous in terms of osseous integration and vascularization. The levels of Zn2+ and Sr2+ detected as a result of degradation of the crystalline phases were found to be 1.4–600 parts per million (ppm) and 0–583 ppm, respectively. The levels detected correlate well with the levels of Sr2+ and Zn2+ions typically associated with clinical benefits, including antibacterial efficacy, osteoblastic differentiation and impaired osteoclastic resorption.
Collapse
Affiliation(s)
| | | | - Daniel Boyd
- Department of Applied Oral Sciences, Dalhousie University, Halifax, Canada, B3H 1W2
| |
Collapse
|
28
|
Patient-to-patient variability in autologous pericardial matrix scaffolds for cardiac repair. J Cardiovasc Transl Res 2011; 4:545-56. [PMID: 21695575 DOI: 10.1007/s12265-011-9293-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Accepted: 06/10/2011] [Indexed: 01/15/2023]
Abstract
The pursuit of alternate therapies for end-stage heart failure post-myocardial infarction has led to the development of a variety of in situ gelling materials to be used as cellular or acellular scaffolds for cardiac repair. Previously, a protocol was established to decellularize human and porcine pericardia and process the extracellular matrix (ECM) into an injectable form. The resulting gels were found to retain components of the native extracellular matrix; cell infiltration was facilitated in vivo, and neovascularization was observed by 2 weeks. However, the assertion that an injectable form of human pericardial tissue could be a potentially autologous scaffold for myocardial tissue engineering requires assessment of the patient-to-patient variability. With this work, seven human pericardia from a relevant patient demographic are processed into injectable matrix materials that gel when brought to physiologic conditions. The resulting materials are compared with respect to their protein composition, glycosaminoglycan content, in vitro degradation, in vivo gelation, and microstructure. It is observed that a diminished collagen content in a subset of samples prevents in vitro gelation but not in vivo gelation at lower ECM concentrations. The structure is similarly fibrous and porous across all samples, implying the cell infiltration may be similarly facilitated. The biochemical composition as characterized by tandem mass spectrometry is comparable; basic ECM components are conserved across all samples, and the presence of a wide variety of ECM proteins and glycoproteins demonstrate the retention of biochemical complexity post-processing. It is concluded that the variability within human pericardial tissue specimens does not prevent them from being processed into injectable scaffolds; therefore, pericardial tissue offers a promising source as an autologous, injectable biomaterial scaffold.
Collapse
|
29
|
Poly(lactic acid) porous scaffold with calcium phosphate mineralized surface and bone marrow mesenchymal stem cell growth and differentiation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2011. [DOI: 10.1016/j.msec.2010.11.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
30
|
Huang C, Zhou Y, Jin Y, Zhou X, Tang Z, Guo X, Zhou S. Preparation and characterization of temperature-responsive and magnetic nanomicelles. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm04264a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
31
|
Joseph B, Edwin BT, Edwin BT, Sankargane P, Raj SJ. Effect of Biomaterials in Orthopaedic Mesenchymal Stem Cell Therapy. JOURNAL OF MEDICAL SCIENCES 2010. [DOI: 10.3923/jms.2011.1.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
32
|
Carletti E, Endogan T, Hasirci N, Hasirci V, Maniglio D, Motta A, Migliaresi C. Microfabrication of PDLLA scaffolds. J Tissue Eng Regen Med 2010; 5:569-77. [DOI: 10.1002/term.349] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 07/08/2010] [Indexed: 11/06/2022]
|
33
|
Lee MN, Mohraz A. Bicontinuous macroporous materials from bijel templates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:4836-4841. [PMID: 20862712 DOI: 10.1002/adma.201001696] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- Matthew N Lee
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA 92697, USA
| | | |
Collapse
|
34
|
Shock Waves Induce Activity of Human Osteoblast-Like Cells in Bioactive Scaffolds. ACTA ACUST UNITED AC 2010; 68:1439-44. [DOI: 10.1097/ta.0b013e3181b28a8c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
35
|
A novel approach via combination of electrospinning and FDM for tri-leaflet heart valve scaffold fabrication. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11706-009-0067-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
36
|
Georgakoudi I, Rice WL, Hronik-Tupaj M, Kaplan DL. Optical spectroscopy and imaging for the noninvasive evaluation of engineered tissues. TISSUE ENGINEERING PART B-REVIEWS 2009; 14:321-40. [PMID: 18844604 DOI: 10.1089/ten.teb.2008.0248] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Optical spectroscopy and imaging approaches offer the potential to noninvasively assess different aspects of the cellular, extracellular matrix, and scaffold components of engineered tissues. In addition, the combination of multiple imaging modalities within a single instrument is highly feasible, allowing acquisition of complementary information related to the structure, organization, biochemistry, and physiology of the sample. The ability to characterize and monitor the dynamic interactions that take place as engineered tissues develop promises to enhance our understanding of the interdependence of processes that ultimately leads to functional tissue outcomes. It is expected that this information will impact significantly upon our abilities to optimize the design of biomaterial scaffolds, bioreactors, and cell systems. Here, we review the principles and performance characteristics of the main methodologies that have been exploited thus far, and we present examples of corresponding tissue engineering studies.
Collapse
Affiliation(s)
- Irene Georgakoudi
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, USA.
| | | | | | | |
Collapse
|
37
|
Verné E, Vitale-Brovarone C, Bui E, Bianchi CL, Boccaccini AR. Surface functionalization of bioactive glasses. J Biomed Mater Res A 2009; 90:981-92. [PMID: 18655138 DOI: 10.1002/jbm.a.32153] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- E Verné
- Department of Materials Science and Chemical Engineering, Politecnico di Torino, C.so Duca Degli Abruzzi 24, 10129 Torino, Italy.
| | | | | | | | | |
Collapse
|
38
|
3-D biomodelling technology for maxillofacial reconstruction. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2008. [DOI: 10.1016/j.msec.2008.02.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
39
|
Qian J, Kang Y, Zhang W, Li Z. Fabrication, chemical composition change and phase evolution of biomorphic hydroxyapatite. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:3373-3383. [PMID: 18545942 DOI: 10.1007/s10856-008-3475-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 05/15/2008] [Indexed: 05/26/2023]
Abstract
Biomorphous, highly porous hydroxyapatite (HA) ceramics have been prepared by a combination of a novel biotemplating process and a sol-gel method, using natural plants like cane and pine as biotemplates. A HA sol was first synthesized from triethylphosphate and calcium nitrate used as the phosphorus and calcium precursors, respectively, and infiltrated into the biotemplates, and subsequently they were sintered at elevated temperatures to obtain porous HA ceramics. The microstructural changes, phase and chemical composition evolutions during the biotemplate-to-HA conversion were investigated by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. The XRD and FT-IR analysis revealed that the dominant phase of the product was HA, which contained a small amount of mixed A/B-type carbonated HA, closely resembling that of human bone apatite. Moreover, the appearance of a small amount of secondary phase CaCO(3) seemed unavoidable. The HA was not transformed to the other calcium phosphate phases up to 1400 degrees C, but it contained a trace amount of CaO when sintered at above 1100 degrees C. The possible transformation mechanism was proposed. The SEM observation and mechanical property test showed that as-produced HA ceramics retained the macro-/micro-porous structures of the biotemplates with high precision, and possessed acceptable mechanical strength, which is suggested to be potential scaffolds for bone tissue engineering.
Collapse
Affiliation(s)
- Junmin Qian
- Xi'an Jiaotong University, Xi'an, 710049, China.
| | | | | | | |
Collapse
|
40
|
Zhou WY, Lee SH, Wang M, Cheung WL, Ip WY. Selective laser sintering of porous tissue engineering scaffolds from poly(L: -lactide)/carbonated hydroxyapatite nanocomposite microspheres. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:2535-40. [PMID: 17619975 DOI: 10.1007/s10856-007-3089-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 05/10/2007] [Indexed: 05/16/2023]
Abstract
This study focuses on the use of bio-nanocomposite microspheres, consisting of carbonated hydroxyapatite (CHAp) nanospheres within a poly(L: -lactide) (PLLA) matrix, to produce tissue engineering (TE) scaffolds using a modified selective laser sintering (SLS) machine. PLLA microspheres and PLLA/CHAp nanocomposite microspheres were prepared by emulsion techniques. The resultant microspheres had a size range of 5-30 microm, suitable for the SLS process. Microstructural analyses revealed that the CHAp nanospheres were embedded throughout the PLLA microsphere, forming a nanocomposite structure. A custom-made miniature sintering platform was installed in a commercial Sinterstation((R)) 2000 SLS machine. This platform allowed the use of small quantities of biomaterials for TE scaffold production. The effects of laser power; scan spacing and part bed temperature were investigated and optimized. Finally, porous scaffolds were successfully fabricated from the PLLA microspheres and PLLA/CHAp nanocomposite microspheres. In particular, the PLLA/CHAp nanocomposite microspheres appeared to be promising for porous bone TE scaffold production using the SLS technique.
Collapse
Affiliation(s)
- Wen You Zhou
- Department of Mechanical Engineering, The University of Hong Kong, China
| | | | | | | | | |
Collapse
|
41
|
del Campo A, Arzt E. Fabrication Approaches for Generating Complex Micro- and Nanopatterns on Polymeric Surfaces. Chem Rev 2008; 108:911-45. [PMID: 18298098 DOI: 10.1021/cr050018y] [Citation(s) in RCA: 379] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Aránzazu del Campo
- Max-Planck-Institut für Metallforschung, Heisenbergstraβe 3, 70569 Stuttgart, Germany
| | - Eduard Arzt
- Max-Planck-Institut für Metallforschung, Heisenbergstraβe 3, 70569 Stuttgart, Germany
| |
Collapse
|
42
|
Gatti R, Orlandini G, Uggeri J, Belletti S, Galli C, Raspanti M, Scandroglio R, Guizzardi S. Analysis of living cells grown on different titanium surfaces by time-lapse confocal microscopy. Micron 2008; 39:137-43. [PMID: 17223563 DOI: 10.1016/j.micron.2006.11.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 11/15/2006] [Accepted: 11/15/2006] [Indexed: 11/24/2022]
Abstract
In this study we have combined fluorescence- and reflection-confocal laser scanning microscopy for the simultaneous visualization of living cells and surface topography beneath them. To this purpose we have designed a specific flow chamber and we have tested it with osteoblasts grown on an opaque, thick support, made of smooth or sandblasted titanium. Cells were loaded with Calcein-AM or tetramethylrhodamine methyl ester (TMRM), two probes employed as indicators of cell viability/morphology and mitochondrial membrane potential, respectively. Besides the acquisition of stacks of confocal sections, the system allowed also vertical views and faithful three-dimensional reconstruction of the samples. Confocal microscope implemented with our flow chamber proved to be a promising tool for time-lapse investigation of cell-biomaterial interactions.
Collapse
Affiliation(s)
- R Gatti
- Department of Experimental Medicine, University of Parma, Via Volturno 39, 43100 Parma, Italy
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Nair MB, Suresh Babu S, Varma HK, John A. A triphasic ceramic-coated porous hydroxyapatite for tissue engineering application. Acta Biomater 2008; 4:173-81. [PMID: 17804309 DOI: 10.1016/j.actbio.2007.07.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 06/25/2007] [Accepted: 07/09/2007] [Indexed: 12/31/2022]
Abstract
Scaffolds which encourage the incorporation of a cell source for tissue engineering applications are critical determinants for clinical defects. Over the years, a number of biomaterials have emerged for cell support and growth, but only a few have demonstrated clinical efficacy. We therefore investigated an in-house-developed silica-based bioactive ceramic for its ability to support and sustain the growth of bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. For this, MSCs aspirated from goat bone marrow were isolated and culture expanded on a novel triphasic ceramic composite coated hydroxyapatite (HASi) scaffold comprising hydroxyapatite, tricalcium phosphate and calcium silicate. The viability of cells that harbored on and within the material was ensured through fluorescence-activated cell sorting and confocal laser scanning microscope and for their anchorage sites by scanning electron microscopy. Interestingly, over the days in culture, cell-cell interactions gradually morphed into woven cell-sheets that spanned across the surface of the HASi, forming a canopy. To conclude, we have attempted to carry out the preliminary cytocompatibility studies of this novel ceramic to establish its appropriateness for bone tissue engineering application which is an important criterion in orthopaedic transplantation and regenerative surgery.
Collapse
Affiliation(s)
- Manitha B Nair
- Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum 695 012, India
| | | | | | | |
Collapse
|
44
|
Gutierres M, Dias AG, Lopes MA, Hussain NS, Cabral AT, Almeida L, Santos JD. Opening wedge high tibial osteotomy using 3D biomodelling Bonelike macroporous structures: case report. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2007; 18:2377-82. [PMID: 17569003 DOI: 10.1007/s10856-007-3171-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Accepted: 09/12/2006] [Indexed: 05/15/2023]
Abstract
Two synthetic calcium phosphates in porous wedge shape, Bonelike and a commercial HA/beta-TCP biphasic material, were used as an alternative to bone autografts and allografts in the treatment of medial compartment osteoarthritis of varus knees. The structure of Bonelike has a 3D architecture that is computer controlled, and a composition that mimics the mineral composition of natural bone. The HA/beta-TCP biphasic material used as a control material in this study was prepared using conventional foaming based methods. No signs of inflammatory reactions were observed post-operatively for both materials. After 4 months signs of fusion at the osteotomy site and good integration of the implanted wedges were observed, showing good mechanical resistance. Concerning the final correction attained, the left knee revealed a satisfactory valgus of 10 degrees , but the right one only had a final value of 6 degrees . The clinical evaluation using International Knee Score (IKS) showed good outcome in all parameters with complete range of motion in both knees and climbing stairs without crutches with only slight pain.
Collapse
Affiliation(s)
- M Gutierres
- FMUP - Faculdade de Medicina da Universidade do Porto, Hospital de São João, Largo Hernâni Monteiro, Porto 4200, Portugal
| | | | | | | | | | | | | |
Collapse
|
45
|
Vitale-Brovarone C, Verné E, Robiglio L, Appendino P, Bassi F, Martinasso G, Muzio G, Canuto R. Development of glass-ceramic scaffolds for bone tissue engineering: characterisation, proliferation of human osteoblasts and nodule formation. Acta Biomater 2007; 3:199-208. [PMID: 17085090 DOI: 10.1016/j.actbio.2006.07.012] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 07/28/2006] [Accepted: 07/31/2006] [Indexed: 11/20/2022]
Abstract
Glass-ceramic macroporous scaffolds for tissue engineering have been developed using a polyurethane sponge template and bioactive glass powders. The starting glass (CEL2) belongs to the system SiO(2)-P(2)O(5)-CaO-MgO-Na(2)O-K(2)O and has been synthesised by a conventional melting-quenching route. A slurry of CEL2 powder, polyvinyl alcohol and water has been prepared in order to coat, by impregnation, the polymeric template. An optimised thermal treatment was then use to remove the sponge and to sinter the glass powders, leading to a glass-ceramic replica of the template. Morphological observations, image analyses, mechanical tests and in vitro tests showed that the obtained devices are good candidates as scaffolds for bone-tissue engineering, in terms of pore-size distribution, pore interconnection, surface roughness, and both bioactivity and biocompatibility. In particular, a human osteoblast cell line (MG-63) seeded onto the scaffold after a standardised preconditioning route in simulated body fluid showed a high degree of cell proliferation and a good ability to produce calcium nodules. The obtained results were enhanced by the addition of bone morphogenetic proteins after cell seeding.
Collapse
Affiliation(s)
- C Vitale-Brovarone
- Materials Science and Chemical Engineering Department, Polytechnic of Turin, Italy.
| | | | | | | | | | | | | | | |
Collapse
|