1
|
Mohammadrezaei D, Podina L, Silva JD, Kohandel M. Cell viability prediction and optimization in extrusion-based bioprinting via neural network-based Bayesian optimization models. Biofabrication 2024; 16:025016. [PMID: 38128119 DOI: 10.1088/1758-5090/ad17cf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/21/2023] [Indexed: 12/23/2023]
Abstract
The fields of regenerative medicine and cancer modeling have witnessed tremendous growth in the application of 3D bioprinting. Maintaining high cell viability throughout the bioprinting process is crucial for the success of this technology, as it directly affects the accuracy of the 3D bioprinted models, the validity of experimental results, and the discovery of new therapeutic approaches. Therefore, optimizing bioprinting conditions, which include numerous variables influencing cell viability during and after the procedure, is of utmost importance to achieve desirable results. So far, these optimizations have been accomplished primarily through trial and error and repeating multiple time-consuming and costly experiments. To address this challenge, we initiated the process by creating a dataset of these parameters for gelatin and alginate-based bioinks and the corresponding cell viability by integrating data obtained in our laboratory and those derived from the literature. Then, we developed machine learning models to predict cell viability based on different bioprinting variables. The trained neural network yielded regressionR2value of 0.71 and classification accuracy of 0.86. Compared to models that have been developed so far, the performance of our models is superior and shows great prediction results. The study further introduces a novel optimization strategy that employs the Bayesian optimization model in combination with the developed regression neural network to determine the optimal combination of the selected bioprinting parameters to maximize cell viability and eliminate trial-and-error experiments. Finally, we experimentally validated the optimization model's performance.
Collapse
Affiliation(s)
- Dorsa Mohammadrezaei
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Lena Podina
- Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Johanna De Silva
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Mohammad Kohandel
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
2
|
Müller WEG, Neufurth M, Wang S, Schröder HC, Wang X. The Physiological Inorganic Polymers Biosilica and Polyphosphate as Key Drivers for Biomedical Materials in Regenerative Nanomedicine. Int J Nanomedicine 2024; 19:1303-1337. [PMID: 38348175 PMCID: PMC10860874 DOI: 10.2147/ijn.s446405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/18/2024] [Indexed: 02/15/2024] Open
Abstract
There is a need for novel nanomaterials with properties not yet exploited in regenerative nanomedicine. Based on lessons learned from the oldest metazoan phylum, sponges, it has been recognized that two previously ignored or insufficiently recognized principles play an essential role in tissue regeneration, including biomineral formation/repair and wound healing. Firstly, the dependence on enzymes as a driving force and secondly, the availability of metabolic energy. The discovery of enzymatic synthesis and regenerative activity of amorphous biosilica that builds the mineral skeleton of siliceous sponges formed the basis for the development of successful strategies for the treatment of osteochondral impairments in humans. In addition, the elucidation of the functional significance of a second regeneratively active inorganic material, namely inorganic polyphosphate (polyP) and its amorphous nanoparticles, present from sponges to humans, has pushed forward the development of innovative materials for both soft (skin, cartilage) and hard tissue (bone) repair. This energy-rich molecule exhibits a property not shown by any other biopolymer: the delivery of metabolic energy, even extracellularly, necessary for the ATP-dependent tissue regeneration. This review summarizes the latest developments in nanobiomaterials based on these two evolutionarily old, regeneratively active materials, amorphous silica and amorphous polyP, highlighting their specific, partly unique properties and mode of action, and discussing their possible applications in human therapy. The results of initial proof-of-concept studies on patients demonstrating complete healing of chronic wounds are outlined.
Collapse
Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| |
Collapse
|
3
|
Mostajeran H, Baheiraei N, Bagheri H. Effects of cerium-doped bioactive glass incorporation on an alginate/gelatin scaffold for bone tissue engineering: In vitro characterizations. Int J Biol Macromol 2024; 255:128094. [PMID: 37977466 DOI: 10.1016/j.ijbiomac.2023.128094] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 11/04/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
Bioactive glasses (BGs) have been extensively employed in treating bone defects due to their capacity to bond and integrate with hard and soft tissues. To promote their characteristics, BGs are doped with therapeutic inorganic ions; Among these, Cerium (Ce) is of special attention because of its material and biological properties. This study aimed to investigate the effects of the addition of Ce to BG on the physicochemical and biological properties of the alginate/gelatin (Alg-Gel) scaffold compared with a similar scaffold that only contains BG45S5. The scaffolds were characterized for their biocompatibility using human bone marrow-derived mesenchymal stem cells (hBM-MSCs) by MTT analysis. The osteogenic differentiation of hBM-MSCs cultured on the scaffolds was assessed by evaluating the alkaline phosphatase (ALP) activity and the expression of osteogenic-related genes. Scanning electron microscopy of the prepared scaffolds showed an interconnected porous structure with an average diameter of 212-272 μm. The Young's modulus of the scaffolds significantly increased from 13 ± 0.82 MPa for Alg-Gel to 91 ± 1.76 MPa for Alg-Gel-BG/Ce. Ce doping improved the osteogenic differentiation of hBM-MSCs and ALP secretion compared to the other samples, even without adding an osteogenic differentiation medium. The obtained results demonstrated the biocompatibility and osteo-inductive potentials of the Alg-Gel-BG/Ce scaffold for bone tissue engineering.
Collapse
Affiliation(s)
- Hossein Mostajeran
- Department of Bio-Computing, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Tehran, Iran
| | - Nafiseh Baheiraei
- Department of Bio-Computing, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Tehran, Iran; Tissue Engineering and Applied Cell Sciences Division, Department of Anatomical Sciences, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Hamed Bagheri
- Department of Bio-Computing, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
4
|
Li Y, Yang L, Hou Y, Zhang Z, Chen M, Wang M, Liu J, Wang J, Zhao Z, Xie C, Lu X. Polydopamine-mediated graphene oxide and nanohydroxyapatite-incorporated conductive scaffold with an immunomodulatory ability accelerates periodontal bone regeneration in diabetes. Bioact Mater 2022; 18:213-227. [PMID: 35387166 PMCID: PMC8961429 DOI: 10.1016/j.bioactmat.2022.03.021] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/22/2022] [Accepted: 03/12/2022] [Indexed: 12/11/2022] Open
Abstract
Regenerating periodontal bone tissues in the aggravated inflammatory periodontal microenvironment under diabetic conditions is a great challenge. Here, a polydopamine-mediated graphene oxide (PGO) and hydroxyapatite nanoparticle (PHA)-incorporated conductive alginate/gelatin (AG) scaffold is developed to accelerate periodontal bone regeneration by modulating the diabetic inflammatory microenvironment. PHA confers the scaffold with osteoinductivity and PGO provides a conductive pathway for the scaffold. The conductive scaffold promotes bone regeneration by transferring endogenous electrical signals to cells and activating Ca2+ channels. Moreover, the scaffold with polydopamine-mediated nanomaterials has a reactive oxygen species (ROS)-scavenging ability and anti-inflammatory activity. It also exhibits an immunomodulatory ability that suppresses M1 macrophage polarization and activates M2 macrophages to secrete osteogenesis-related cytokines by mediating glycolytic and RhoA/ROCK pathways in macrophages. The scaffold induces excellent bone regeneration in periodontal bone defects of diabetic rats because of the synergistic effects of good conductive, ROS-scavenging, anti-inflammatory, and immunomodulatory abilities. This study provides fundamental insights into the synergistical effects of conductivity, osteoinductivity, and immunomodulatory abilities on bone regeneration and offers a novel strategy to design immunomodulatory biomaterials for treatment of immune-related diseases and tissue regeneration. The conductive PGO-PHA-AG scaffold can activate Ca2+ channels. •The PGO-PHA-AG scaffold had ROS-scavenging and anti-inflammatory activities. •The scaffold exhibited an immunomodulatory ability. •The scaffold induced excellent periodontal bone regeneration in diabetes.
Collapse
Affiliation(s)
- Yazhen Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Lu Yang
- Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 610031, China
| | - Yue Hou
- Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 610031, China
| | - Zhenzhen Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Miao Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Maoxia Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Jin Liu
- Lab for Aging Research and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Jun Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
- Corresponding author.
| | - Zhihe Zhao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
- Corresponding author.
| | - Chaoming Xie
- Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 610031, China
- Corresponding author.
| | - Xiong Lu
- Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 610031, China
- Corresponding author.
| |
Collapse
|
5
|
Gharacheh H, Guvendiren M. Cell-Laden Composite Hydrogel Bioinks with Human Bone Allograft Particles to Enhance Stem Cell Osteogenesis. Polymers (Basel) 2022; 14:polym14183788. [PMID: 36145933 PMCID: PMC9503810 DOI: 10.3390/polym14183788] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
There is a growing demand for bone graft substitutes that mimic the extracellular matrix properties of the native bone tissue to enhance stem cell osteogenesis. Composite hydrogels containing human bone allograft particles are particularly interesting due to inherent bioactivity of the allograft tissue. Here, we report a novel photocurable composite hydrogel bioink for bone tissue engineering. Our composite bioink is formulated by incorporating human allograft bone particles in a methacrylated alginate formulation to enhance adult human mesenchymal stem cell (hMSC) osteogenesis. Detailed rheology and printability studies confirm suitability of our composite bioinks for extrusion-based 3D bioprinting technology. In vitro studies reveal high cell viability (~90%) for hMSCs up to 28 days of culture within 3D bioprinted composite scaffolds. When cultured within bioprinted composite scaffolds, hMSCs show significantly enhanced osteogenic differentiation as compared to neat scaffolds based on alkaline phosphatase activity, calcium deposition, and osteocalcin expression.
Collapse
Affiliation(s)
- Hadis Gharacheh
- Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Murat Guvendiren
- Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
- Correspondence:
| |
Collapse
|
6
|
Schröder HC, Wang X, Neufurth M, Wang S, Müller WEG. Biomimetic Polyphosphate Materials: Toward Application in Regenerative Medicine. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2022; 61:83-130. [PMID: 35697938 DOI: 10.1007/978-3-031-01237-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In recent years, inorganic polyphosphate (polyP) has attracted increasing attention as a biomedical polymer or biomaterial with a great potential for application in regenerative medicine, in particular in the fields of tissue engineering and repair. The interest in polyP is based on two properties of this physiological polymer that make polyP stand out from other polymers: polyP has morphogenetic activity by inducing cell differentiation through specific gene expression, and it functions as an energy store and donor of metabolic energy, especially in the extracellular matrix or in the extracellular space. No other biopolymer applicable in tissue regeneration/repair is known that is endowed with this combination of properties. In addition, polyP can be fabricated both in the form of a biologically active coacervate and as biomimetic amorphous polyP nano/microparticles, which are stable and are activated by transformation into the coacervate phase after contact with protein/body fluids. PolyP can be used in the form of various metal salts and in combination with various hydrogel-forming polymers, whereby (even printable) hybrid materials with defined porosities and mechanical and biological properties can be produced, which can even be loaded with cells for 3D cell printing or with drugs and support the growth and differentiation of (stem) cells as well as cell migration/microvascularization. Potential applications in therapy of bone, cartilage and eye disorders/injuries and wound healing are summarized and possible mechanisms are discussed.
Collapse
Affiliation(s)
- Heinz C Schröder
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Werner E G Müller
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| |
Collapse
|
7
|
Pan Z, Huang Y, Guo H, Huang T, Wen G, Yu H, He J. Synthesis of dual
pH
‐ and temperature‐sensitive poly(N‐isopropylacrylamide‐co‐acrylic acid)/sewage sludge ash hydrogel with the simultaneously high performance of swelling and deswelling. POLYM ADVAN TECHNOL 2021. [DOI: 10.1002/pat.5509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Zhihui Pan
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta Guangzhou University Guangzhou China
- School of Civil Engineering Guangzhou University Guangzhou China
| | - Yingru Huang
- School of Civil Engineering Guangzhou University Guangzhou China
| | - Haoyong Guo
- School of Civil Engineering Guangzhou University Guangzhou China
| | - Tingjian Huang
- School of Civil Engineering Guangzhou University Guangzhou China
| | - Gang Wen
- Shanxi Key Laboratory of Environmental Engineering Xi'an University of Architecture and Technology Xi'an China
| | - Huarong Yu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta Guangzhou University Guangzhou China
- School of Civil Engineering Guangzhou University Guangzhou China
| | - Junguo He
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta Guangzhou University Guangzhou China
- School of Civil Engineering Guangzhou University Guangzhou China
| |
Collapse
|
8
|
Biomimetic Alginate/Gelatin Cross-Linked Hydrogels Supplemented with Polyphosphate for Wound Healing Applications. Molecules 2020; 25:molecules25215210. [PMID: 33182366 PMCID: PMC7664853 DOI: 10.3390/molecules25215210] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/27/2020] [Accepted: 11/06/2020] [Indexed: 11/17/2022] Open
Abstract
In the present study, the fabrication of a biomimetic wound dressing that mimics the extracellular matrix, consisting of a hydrogel matrix composed of non-oxidized and periodate-oxidized marine alginate, was prepared to which gelatin was bound via Schiff base formation. Into this alginate/oxidized-alginate-gelatin hydrogel, polyP was stably but reversibly integrated by ionic cross-linking with Zn2+ ions. Thereby, a soft hybrid material is obtained, consisting of a more rigid alginate scaffold and porous structures formed by the oxidized-alginate-gelatin hydrogel with ionically cross-linked polyP. Two forms of the Zn-polyP-containing matrices were obtained based on the property of polyP to form, at neutral pH, a coacervate—the physiologically active form of the polymer. At alkaline conditions (pH 10), it will form nanoparticles, acting as a depot that is converted at pH 7 into the coacervate phase. Both polyP-containing hydrogels were biologically active and significantly enhanced cell growth/viability and attachment/spreading of human epidermal keratinocytes compared to control hydrogels without any adverse effect on reconstructed human epidermis samples in an in vitro skin irritation test system. From these data, we conclude that polyP-containing alginate/oxidized-alginate-gelatin hydrogels may provide a suitable regeneratively active matrix for wound healing for potential in vivo applications.
Collapse
|
9
|
Purohit SD, Singh H, Bhaskar R, Yadav I, Chou CF, Gupta MK, Mishra NC. Gelatin—alginate—cerium oxide nanocomposite scaffold for bone regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 116:111111. [DOI: 10.1016/j.msec.2020.111111] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/18/2022]
|
10
|
Ojha N, Das N. Fabrication and characterization of biodegradable PHBV/SiO 2 nanocomposite for thermo-mechanical and antibacterial applications in food packaging. IET Nanobiotechnol 2020; 14:785-795. [PMID: 33399109 DOI: 10.1049/iet-nbt.2020.0066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In the present study, biogenic silica nanoparticles (bSNPs) were synthesized from groundnut shells, and thoroughly characterized to understand its phase, and microstructure properties. The biopolymer was synthesized from yeast Wickerhamomyces anomalus and identified as Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by GC-MS and NMR analysis. The bSNPs were reinforced to fabricate PHBV/SiO2 nanocomposites via solution casting technique. The fabricated PHBV/SiO2 nanocomposites revealed intercalated hybrid interaction between the bSNPs and PHBV matrix through XRD analysis. PHBV/SiO2 nanocomposites showed significant improvement in physical, chemical, thermo-mechanical and biodegradation properties as compared to the bare PHBV. The cell viability study revealed excellent biocompatibility against L929 mouse fibroblast cells. The antibacterial activity of PHBV/SiO2 nanocomposites was found to be progressively improved upon increasing bSNPs concentration against E. coli and S. aureus.
Collapse
Affiliation(s)
- Nupur Ojha
- Bioremediation Laboratory, Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India
| | - Nilanjana Das
- Bioremediation Laboratory, Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
| |
Collapse
|
11
|
Alginate hydrogels for bone tissue engineering, from injectables to bioprinting: A review. Carbohydr Polym 2020; 229:115514. [DOI: 10.1016/j.carbpol.2019.115514] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 10/08/2019] [Accepted: 10/20/2019] [Indexed: 12/16/2022]
|
12
|
|
13
|
Zamani D, Moztarzadeh F, Bizari D. Alginate-bioactive glass containing Zn and Mg composite scaffolds for bone tissue engineering. Int J Biol Macromol 2019; 137:1256-1267. [DOI: 10.1016/j.ijbiomac.2019.06.182] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 06/16/2019] [Accepted: 06/24/2019] [Indexed: 12/22/2022]
|
14
|
Dashnyam K, Buitrago JO, Bold T, Mandakhbayar N, Perez RA, Knowles JC, Lee JH, Kim HW. Angiogenesis-promoted bone repair with silicate-shelled hydrogel fiber scaffolds. Biomater Sci 2019; 7:5221-5231. [DOI: 10.1039/c9bm01103j] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The silicate-shelled alginate hydrogel fiber scaffold is highly effective for promoting ion-induced angiogenesis and bone bioactivity, ultimately useful for the repair and regeneration of hard tissues.
Collapse
Affiliation(s)
- Khandmaa Dashnyam
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Jennifer O. Buitrago
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Tsendmaa Bold
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Nandin Mandakhbayar
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Roman A. Perez
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Jonathan C. Knowles
- UCL Eastman-Korea Dental Medicine Innovation Centre
- Dankook University
- Republic of Korea
- Division of Biomaterials and Tissue Engineering
- Eastman Dental Institute
| | - Jung-Hwan Lee
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| | - Hae-Won Kim
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Republic of Korea
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine
- Dankook University
| |
Collapse
|
15
|
Zhao ZB, Xie HJ, Li YL, Jiang Y. A multi-responsive multicomponent hydrogel with micro-phase separation structure: Synthesis and special drug release. J Drug Deliv Sci Technol 2016. [DOI: 10.1016/j.jddst.2016.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
16
|
You F, Wu X, Chen X. 3D printing of porous alginate/gelatin hydrogel scaffolds and their mechanical property characterization. INT J POLYM MATER PO 2016. [DOI: 10.1080/00914037.2016.1201830] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Fu You
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Xia Wu
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Xiongbiao Chen
- Division of Biomedical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
- Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, Saskatoon, Canada
| |
Collapse
|
17
|
Müller WE, Neufurth M, Tolba E, Wang S, Geurtsen W, Feng Q, Schröder HC, Wang X. A biomimetic approach to ameliorate dental hypersensitivity by amorphous polyphosphate microparticles. Dent Mater 2016; 32:775-83. [DOI: 10.1016/j.dental.2016.03.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 02/10/2016] [Accepted: 03/22/2016] [Indexed: 12/30/2022]
|
18
|
Bioprinting three-dimensional cell-laden tissue constructs with controllable degradation. Sci Rep 2016; 6:24474. [PMID: 27091175 PMCID: PMC4835808 DOI: 10.1038/srep24474] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 03/30/2016] [Indexed: 12/24/2022] Open
Abstract
Alginate hydrogel is a popular biologically inert material that is widely used in 3D bioprinting, especially in extrusion-based printing. However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state. Here, we report a novel study of the 3D printing of human corneal epithelial cells (HCECs)/collagen/gelatin/alginate hydrogel incubated with a medium containing sodium citrate to obtain degradation-controllable cell-laden tissue constructs. The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%). By altering the mole ratio of sodium citrate/sodium alginate, the degradation time of the bioprinting constructs can be controlled. Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.
Collapse
|
19
|
Müller WE, Tolba E, Schröder HC, Muñoz-Espí R, Diehl-Seifert B, Wang X. Amorphous polyphosphate-hydroxyapatite: A morphogenetically active substrate for bone-related SaOS-2 cells in vitro. Acta Biomater 2016; 31:358-367. [PMID: 26654764 DOI: 10.1016/j.actbio.2015.11.060] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/24/2015] [Accepted: 11/29/2015] [Indexed: 12/22/2022]
Abstract
There is increasing evidence that inorganic calcium-polyphosphates (polyP) are involved in human bone hydroxyapatite (HA) formation. Here we investigated the morphology of the particles, containing calcium phosphate (CaP) with different concentrations of various Na-polyP concentrations, as well as their effects in cell culture. We used both SaOS-2 cells and human mesenchymal stem cells. The polymeric phosphate readily binds calcium ions under formation of insoluble precipitates. We found that addition of low concentrations of polyP (<10wt.%, referred to the CaP deposits) results in an increased size of the HA crystals. Surprisingly, at higher polyP concentrations (>10wt.%) the formation of crystalline HA is prevented and amorphous polyP/HA hybrid particles with a size of ≈50nm are formed, most likely consisting of polyP molecules linked via Ca(2+) bridges to the surface of the CaP deposits. Further studies revealed that the polyP-CaP particles cause a strong upregulation of the expression of the genes encoding for two marker proteins of bone formation, collagen type I and alkaline phosphatase. Based on their morphogenetic activity the amorphous polyP-CaP particles offer a promising material for the development of bone implants, formed from physiological inorganic precursors/polymers. STATEMENT OF SIGNIFICANCE Hydroxyapatite (HA) is a naturally occurring mineral of vertebrate bone. Natural HA, a bio-ceramic material which is crystalline to different scale, has been used as a biomaterial to fabricate scaffolds for in situ bone regeneration and other tissue engineering purposes. In contrast to natural HA, synthetic apatite is much less effective. In general, while HA is bioactive, its interaction and biocompatibility with existing bone tissue is low. These properties have been attributed to a minimal degradability in the physiological environment. In the present study we introduce a new Ca-phosphate (CaP) fabrication technology, starting from calcium chloride and dibasic ammonium phosphate with the HA characteristic Ca/P molar ratio of 10:6 and report that after addition >10% (by weight) of polyphosphate (polyP) amorphous CaP/HA samples were obtained. Those samples elicits strong morphogenetic activity let us to conclude that polyP/HA-based material might be beneficial for application as bone substitute implant.
Collapse
|
20
|
|
21
|
Zhao F, Zhang W, Fu X, Xie W, Chen X. Fabrication and characterization of bioactive glass/alginate composite scaffolds by a self-crosslinking processing for bone regeneration. RSC Adv 2016. [DOI: 10.1039/c6ra18309c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bioactive glass/alginate composite scaffolds were fabricated through a self-crosslinking process by bioactive glass microspheres provided Ca2+completely.
Collapse
Affiliation(s)
- Fujian Zhao
- Department of Biomedical Engineering
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641
- China
| | - Wen Zhang
- Department of Biomedical Engineering
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641
- China
| | - Xiaoling Fu
- Department of Biomedical Engineering
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641
- China
| | - Weihan Xie
- Department of Biomedical Engineering
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641
- China
| | - Xiaofeng Chen
- Department of Biomedical Engineering
- School of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510641
- China
| |
Collapse
|
22
|
Müller WEG, Ackermann M, Tolba E, Neufurth M, Wang S, Schröder HC, Wang X. A bio-imitating approach to fabricate an artificial matrix for cartilage tissue engineering using magnesium-polyphosphate and hyaluronic acid. RSC Adv 2016. [DOI: 10.1039/c6ra17043a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Here we describe an cartilage-like material based on a hyaluronic acid-Mg/Ca-polyphosphate that is fabricated from a water-soluble Na-salt of energy-rich inorganic polyphosphate and soluble hyaluronic acid in the presence of water-insoluble CaCO3.
Collapse
Affiliation(s)
- Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy
- University Medical Center of the Johannes Gutenberg University
- D-55099 Mainz
- Germany
| | - Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| |
Collapse
|
23
|
Huayao C, Yueshun L, Hongjun Z, Xinhua Z, Sheng G, Hua X. Highly efficient alginate sodium encapsulated chlorpyrifos/copper(ii) Schiff base mesoporous silica sustained release system with pH and ion response for pesticide delivery. RSC Adv 2016. [DOI: 10.1039/c6ra23836j] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A highly efficient sustained released system (ALG–CH–Cu–MCM-41) was prepared. The as-synthesized system showed significant pH and ion responsive.
Collapse
Affiliation(s)
- Chen Huayao
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| | - Lin Yueshun
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| | - Zhou Hongjun
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| | - Zhou Xinhua
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| | - Gong Sheng
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| | - Xu Hua
- College of Chemistry and Chemical Engineering
- Zhongkai University of Agriculture and Engineering
- Guangzhou 510225
- China
| |
Collapse
|
24
|
Tolba E, Müller WEG, Abd El-Hady BM, Neufurth M, Wurm F, Wang S, Schröder HC, Wang X. High biocompatibility and improved osteogenic potential of amorphous calcium carbonate/vaterite. J Mater Chem B 2015; 4:376-386. [PMID: 32263204 DOI: 10.1039/c5tb02228b] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In human bone, amorphous calcium carbonate (ACC) is formed as a precursor of the crystalline carbonated apatite/hydroxyapatite (HA). Here we describe that the metastable ACC phase can be stabilized by inorganic polyphosphate (polyP) that is also used as a phosphate source for the non-enzymatic carbonate/phosphate exchange during HA formation. This polymer was found to suppress the transformation of ACC into crystalline CaCO3 at a percentage of 5% [w/w] ("CCP5") with respect to CaCO3 and almost completely at 10% [w/w] ("CCP10"). Both preparations (CaCO3/polyP) are amorphous, but also contain small amounts of vaterite, as revealed by XRD, FTIR and SEM analyses. They did not affect the growth/viability of SaOS-2 cells. Cell culture and Ca2+ release experiments revealed that the CaCO3 particles formed in the presence of polyP (CaCO3/polyP) are degradable and, unlike calcite, become disintegrated with time during the cell culture incubation. Again in contrast to calcite, "CCP5" and "CCP10" were found to exhibit osteogenic activity and induce the expression of alkaline phosphatase gene in SaOS-2 cells as well as in human mesenchymal stem cells (MSC). In vivo studies in rats, using PLGA microspheres inserted in the muscles of the back of the animals, revealed that the encapsulated "CCP10" is not only biocompatible but also supports the regeneration at the implant region. We conclude that ACC containing small amounts of vaterite has osteogenic potential and offers superior properties compared to the biologically inert calcite with respect to a potential application as a scaffold material for bone implants.
Collapse
Affiliation(s)
- Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Zhao F, Yao D, Guo R, Deng L, Dong A, Zhang J. Composites of Polymer Hydrogels and Nanoparticulate Systems for Biomedical and Pharmaceutical Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2015; 5:2054-2130. [PMID: 28347111 PMCID: PMC5304774 DOI: 10.3390/nano5042054] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/18/2015] [Accepted: 11/20/2015] [Indexed: 12/25/2022]
Abstract
Due to their unique structures and properties, three-dimensional hydrogels and nanostructured particles have been widely studied and shown a very high potential for medical, therapeutic and diagnostic applications. However, hydrogels and nanoparticulate systems have respective disadvantages that limit their widespread applications. Recently, the incorporation of nanostructured fillers into hydrogels has been developed as an innovative means for the creation of novel materials with diverse functionality in order to meet new challenges. In this review, the fundamentals of hydrogels and nanoparticles (NPs) were briefly discussed, and then we comprehensively summarized recent advances in the design, synthesis, functionalization and application of nanocomposite hydrogels with enhanced mechanical, biological and physicochemical properties. Moreover, the current challenges and future opportunities for the use of these promising materials in the biomedical sector, especially the nanocomposite hydrogels produced from hydrogels and polymeric NPs, are discussed.
Collapse
Affiliation(s)
- Fuli Zhao
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Dan Yao
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Ruiwei Guo
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Liandong Deng
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Anjie Dong
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Jianhua Zhang
- Department of Polymer Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| |
Collapse
|
26
|
Müller WEG, Tolba E, Schröder HC, Wang X. Polyphosphate: A Morphogenetically Active Implant Material Serving as Metabolic Fuel for Bone Regeneration. Macromol Biosci 2015; 15:1182-1197. [DOI: 10.1002/mabi.201500100] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry; University Medical Center of the Johannes Gutenberg University; Duesbergweg 6; D-55128 Mainz Germany
| | - Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry; University Medical Center of the Johannes Gutenberg University; Duesbergweg 6; D-55128 Mainz Germany
- Biomaterials Department; Inorganic Chemical Industries Division; National Research Center; Doki Cairo; 11884 Egypt
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry; University Medical Center of the Johannes Gutenberg University; Duesbergweg 6; D-55128 Mainz Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry; University Medical Center of the Johannes Gutenberg University; Duesbergweg 6; D-55128 Mainz Germany
| |
Collapse
|
27
|
Venkatesan J, Bhatnagar I, Manivasagan P, Kang KH, Kim SK. Alginate composites for bone tissue engineering: A review. Int J Biol Macromol 2015; 72:269-81. [DOI: 10.1016/j.ijbiomac.2014.07.008] [Citation(s) in RCA: 417] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/26/2014] [Accepted: 07/04/2014] [Indexed: 12/20/2022]
|
28
|
Luo Y, Lode A, Akkineni AR, Gelinsky M. Concentrated gelatin/alginate composites for fabrication of predesigned scaffolds with a favorable cell response by 3D plotting. RSC Adv 2015. [DOI: 10.1039/c5ra04308e] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Developed concentrated gelatin/alginate with/without HAP composites were plotted into pre-designed scaffolds, which showed good cells attachments and penetration.
Collapse
Affiliation(s)
- Yongxiang Luo
- Centre for Translational Bone
- Joint and Soft Tissue Research
- University Hospital Carl Gustav Carus and Faculty of Medicine
- Technische Universität Dresden
- Germany
| | - Anja Lode
- Centre for Translational Bone
- Joint and Soft Tissue Research
- University Hospital Carl Gustav Carus and Faculty of Medicine
- Technische Universität Dresden
- Germany
| | - Ashwini Rahul Akkineni
- Centre for Translational Bone
- Joint and Soft Tissue Research
- University Hospital Carl Gustav Carus and Faculty of Medicine
- Technische Universität Dresden
- Germany
| | - Michael Gelinsky
- Centre for Translational Bone
- Joint and Soft Tissue Research
- University Hospital Carl Gustav Carus and Faculty of Medicine
- Technische Universität Dresden
- Germany
| |
Collapse
|
29
|
Müller WEG, Tolba E, Schröder HC, Wang S, Glasser G, Diehl-Seifert B, Wang X. Biologizing titanium alloy implant material with morphogenetically active polyphosphate. RSC Adv 2015. [DOI: 10.1039/c5ra14240g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
As a further step towards a new generation of bone implant materials, we developed a procedure for biological functionalization of titanium alloy surfaces with inorganic calcium polyphosphate (Ca-polyP).
Collapse
Affiliation(s)
- Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- D-55128 Mainz
- Germany
| | - Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- D-55128 Mainz
- Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- D-55128 Mainz
- Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- D-55128 Mainz
- Germany
| | - Gunnar Glasser
- Max Planck Institute for Polymer Research
- 55128 Mainz
- Germany
| | | | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- D-55128 Mainz
- Germany
| |
Collapse
|
30
|
Müller WEG, Tolba E, Schröder HC, Neufurth M, Wang S, Link T, Al-Nawas B, Wang X. A new printable and durable N,O-carboxymethyl chitosan–Ca2+–polyphosphate complex with morphogenetic activity. J Mater Chem B 2015; 3:1722-1730. [DOI: 10.1039/c4tb01586j] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In the absence of Ca2+ the polymers N,O-carboxymethyl chitosan, together with Na-polyphosphate and alginate, form random-coiled structures. Addition of Ca2+ transforms these polymers to durable implants.
Collapse
Affiliation(s)
- Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
- Biomaterials Department
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Thorben Link
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| | - Bilal Al-Nawas
- Department of Oral and Maxillofacial Surgery
- Plastic Surgery
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55131 Mainz
- Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University Mainz
- D-55128 Mainz
- Germany
| |
Collapse
|
31
|
Wang X, Tolba E, Schröder HC, Neufurth M, Feng Q, Diehl-Seifert B, Müller WEG. Effect of bioglass on growth and biomineralization of SaOS-2 cells in hydrogel after 3D cell bioprinting. PLoS One 2014; 9:e112497. [PMID: 25383549 PMCID: PMC4226565 DOI: 10.1371/journal.pone.0112497] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 10/15/2014] [Indexed: 12/16/2022] Open
Abstract
We investigated the effect of bioglass (bioactive glass) on growth and mineralization of bone-related SaOS-2 cells, encapsulated into a printable and biodegradable alginate/gelatine hydrogel. The hydrogel was supplemented either with polyphosphate (polyP), administered as polyP • Ca2+-complex, or silica, or as biosilica that had been enzymatically prepared from ortho-silicate by silicatein. These hydrogels, together with SaOS-2 cells, were bioprinted to computer-designed scaffolds. The results revealed that bioglass (nano)particles, with a size of 55 nm and a molar ratio of SiO2 : CaO : P2O5 of 55 : 40 : 5, did not affect the growth of the encapsulated cells. If silica, biosilica, or polyP • Ca2+-complex is co-added to the cell-containing alginate/gelatin hydrogel the growth behavior of the cells is not changed. Addition of 5 mg/ml of bioglass particles to this hydrogel significantly enhanced the potency of the entrapped SaOS-2 cells to mineralize. If compared with the extent of the cells to form mineral deposits in the absence of bioglass, the cells exposed to bioglass together with 100 µmoles/L polyP • Ca2+-complex increased their mineralization activity from 2.1- to 3.9-fold, or with 50 µmoles/L silica from 1.8- to 2.9-fold, or with 50 µmoles/L biosilica from 2.7- to 4.8-fold or with the two components together (100 µmoles/L polyP • Ca2+-complex and 50 µmoles/L biosilica) from 4.1- to 6.8-fold. Element analysis by EDX spectrometry of the mineral nodules formed by SaOS-2 revealed an accumulation of O, P, Ca and C, indicating that the mineral deposits contain, besides Ca-phosphate also Ca-carbonate. The results show that bioglass added to alginate/gelatin hydrogel increases the proliferation and mineralization of bioprinted SaOS-2 cells. We conclude that the development of cell-containing scaffolds consisting of a bioprintable, solid and cell-compatible inner matrix surrounded by a printable hard and flexible outer matrix containing bioglass, provide a suitable strategy for the fabrication of morphogenetically active and biodegradable implants.
Collapse
Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Biomaterials Department, Inorganic Chemical Industries Division, National Research Center, Cairo, Egypt
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | | | - Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| |
Collapse
|
32
|
Enzyme-based biosilica and biocalcite: biomaterials for the future in regenerative medicine. Trends Biotechnol 2014; 32:441-7. [DOI: 10.1016/j.tibtech.2014.05.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 05/07/2014] [Accepted: 05/13/2014] [Indexed: 12/11/2022]
|
33
|
Müller WE, Tolba E, Schröder HC, Diehl-Seifert B, Link T, Wang X. Biosilica-loaded poly(ϵ-caprolactone) nanofibers mats provide a morphogenetically active surface scaffold for the growth and mineralization of the osteoclast-related SaOS-2 cells. Biotechnol J 2014; 9:1312-21. [DOI: 10.1002/biot.201400277] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 05/31/2014] [Accepted: 06/30/2014] [Indexed: 11/07/2022]
|
34
|
Neufurth M, Wang X, Schröder HC, Feng Q, Diehl-Seifert B, Ziebart T, Steffen R, Wang S, Müller WEG. Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells. Biomaterials 2014; 35:8810-8819. [PMID: 25047630 DOI: 10.1016/j.biomaterials.2014.07.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/01/2014] [Indexed: 11/25/2022]
Abstract
Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca(2+)-complex], resulted in a marked increase in cell proliferation. In the presence of 100 μm polyP·Ca(2+)-complex, the cells proliferate with a generation time of approximately 47-55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially increases in the presence of the polymer. The reduced Young's modulus for the alginate/gelatin hydrogel is approximately 13-14 kPa, and this value drops to approximately 0.5 kPa after incubation of the cell containing scaffolds for 5 d. In the presence of 100 μm polyP·Ca(2+)-complex, the reduced Young's modulus increases to about 22 kPa. The hardness of the polyP·Ca(2+)-complex containing hydrogel remains essentially constant if cells are absent in the matrix, but it drops to 3.2 kPa after a 5 d incubation period in the presence of SaOS-2 cells, indicating that polyP·Ca(2+)-complex becomes metabolized, degraded, by the cells. The alginate/gelatine-agarose system with polyP·Ca(2+)-complex cause a significant increase in the mineralization of the cells. SEM analyses revealed that the morphology of the mineral nodules formed on the surface of the cells embedded in the alginate/gelatin hydrogel do not significantly differ from the nodules on cells growing in monolayer cultures. The newly developed technique, using cells encapsulated into an alginate/gelatin hydrogel and a secondary layer containing the morphogenetically active, growth promoting polymer polyP·Ca(2+)-complex opens new possibilities for the application of 3D bioprinting in bone tissue engineering.
Collapse
Affiliation(s)
- Meik Neufurth
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Qingling Feng
- School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, China
| | | | - Thomas Ziebart
- Department of Oral and Maxillifacial Surgery, University Medicine Mainz, Augustusplatz 2, 55131 Mainz, Germany
| | - Renate Steffen
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Werner E G Müller
- ERC Advanced Investigator Grant Research Group at The Institute for Physiological Chemistry, University Medical Center of The Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
| |
Collapse
|
35
|
Wang X, Schröder HC, Müller WEG. Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:610-621. [PMID: 24991497 PMCID: PMC4077312 DOI: 10.3762/bjnano.5.72] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 04/16/2014] [Indexed: 05/31/2023]
Abstract
Calcium carbonate is the material that builds up the spicules of the calcareous sponges. Recent results revealed that the calcium carbonate/biocalcite-based spicular skeleton of these animals is formed through an enzymatic mechanism, such as the skeleton of the siliceous sponges, evolutionarily the oldest animals that consist of biosilica. The enzyme that mediates the calcium carbonate deposition has been identified as a carbonic anhydrase (CA) and has been cloned from the calcareous sponge species Sycon raphanus. Calcium carbonate deposits are also found in vertebrate bones besides the main constituent, calcium phosphate/hydroxyapatite (HA). Evidence has been presented that during the initial phase of HA synthesis poorly crystalline carbonated apatite is deposited. Recent data summarized here indicate that during early bone formation calcium carbonate deposits enzymatically formed by CA, act as potential bioseeds for the precipitation of calcium phosphate mineral onto bone-forming osteoblasts. Two different calcium carbonate phases have been found during CA-driven enzymatic calcium carbonate deposition in in vitro assays: calcite crystals and round-shaped vaterite deposits. The CA provides a new target of potential anabolic agents for treatment of bone diseases; a first CA activator stimulating the CA-driven calcium carbonate deposition has been identified. In addition, the CA-driven calcium carbonate crystal formation can be frozen at the vaterite state in the presence of silintaphin-2, an aspartic acid/glutamic acid-rich sponge-specific protein. The discovery that calcium carbonate crystals act as bioseeds in human bone formation may allow the development of novel biomimetic scaffolds for bone tissue engineering. Na-alginate hydrogels, enriched with biosilica, have recently been demonstrated as a suitable matrix to embed bone forming cells for rapid prototyping bioprinting/3D cell printing applications.
Collapse
Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Werner E G Müller
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| |
Collapse
|
36
|
Wang X, Schröder HC, Grebenjuk V, Diehl-Seifert B, Mailänder V, Steffen R, Schloßmacher U, Müller WEG. The marine sponge-derived inorganic polymers, biosilica and polyphosphate, as morphogenetically active matrices/scaffolds for the differentiation of human multipotent stromal cells: potential application in 3D printing and distraction osteogenesis. Mar Drugs 2014; 12:1131-47. [PMID: 24566262 PMCID: PMC3944534 DOI: 10.3390/md12021131] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/10/2014] [Accepted: 02/17/2014] [Indexed: 01/03/2023] Open
Abstract
The two marine inorganic polymers, biosilica (BS), enzymatically synthesized from ortho-silicate, and polyphosphate (polyP), a likewise enzymatically synthesized polymer consisting of 10 to >100 phosphate residues linked by high-energy phosphoanhydride bonds, have previously been shown to display a morphogenetic effect on osteoblasts. In the present study, the effect of these polymers on the differential differentiation of human multipotent stromal cells (hMSC), mesenchymal stem cells, that had been encapsulated into beads of the biocompatible plant polymer alginate, was studied. The differentiation of the hMSCs in the alginate beads was directed either to the osteogenic cell lineage by exposure to an osteogenic medium (mineralization activation cocktail; differentiation into osteoblasts) or to the chondrogenic cell lineage by incubating in chondrocyte differentiation medium (triggering chondrocyte maturation). Both biosilica and polyP, applied as Ca²⁺ salts, were found to induce an increased mineralization in osteogenic cells; these inorganic polymers display also morphogenetic potential. The effects were substantiated by gene expression studies, which revealed that biosilica and polyP strongly and significantly increase the expression of bone morphogenetic protein 2 (BMP-2) and alkaline phosphatase (ALP) in osteogenic cells, which was significantly more pronounced in osteogenic versus chondrogenic cells. A differential effect of the two polymers was seen on the expression of the two collagen types, I and II. While collagen Type I is highly expressed in osteogenic cells, but not in chondrogenic cells after exposure to biosilica or polyP, the upregulation of the steady-state level of collagen Type II transcripts in chondrogenic cells is comparably stronger than in osteogenic cells. It is concluded that the two polymers, biosilica and polyP, are morphogenetically active additives for the otherwise biologically inert alginate polymer. It is proposed that alginate, supplemented with polyP and/or biosilica, is a suitable biomaterial that promotes the growth and differentiation of hMSCs and might be beneficial for application in 3D tissue printing of hMSCs and for the delivery of hMSCs in fractures, surgically created during distraction osteogenesis.
Collapse
Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Vladislav Grebenjuk
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | | | - Volker Mailänder
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55129 Mainz, Germany.
| | - Renate Steffen
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Ute Schloßmacher
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Werner E G Müller
- ERC Advanced Investigator Grant Research Group, Institute for Physiological Chemistry, University Medical Center, Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| |
Collapse
|
37
|
Mendoza-Novelo B, Lona-Ramos MC, González-García G, Castellano LE, Delgado J, Cuellar-Mata P, Flores-Moreno JM, Vargas J, Gutiérrez JA, Ávila EE, Mata-Mata JL. Incorporation of silica particles into decellularized tissue biomaterial and its effect on macrophage activation. RSC Adv 2014. [DOI: 10.1039/c4ra08984g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Secretion of signaling molecules by macrophages is induced by silica particles deposited onto decellularized tissue derived biomaterials.
Collapse
Affiliation(s)
| | - María C. Lona-Ramos
- Depto. de Ingenierías Química
- Electrónica y Biomédica
- DCI
- Universidad de Guanajuato
- León, México
| | | | - Laura E. Castellano
- Depto. de Ciencias Aplicadas al Trabajo
- DCS
- Universidad de Guanajuato
- León, México
| | - Jorge Delgado
- Depto. de Ingenierías Química
- Electrónica y Biomédica
- DCI
- Universidad de Guanajuato
- León, México
| | | | | | - Juan Vargas
- IPN-Unidad Profesional Interdisciplinaria de Ingenierías Campus Guanajuato
- Silao de la Victoria, México
| | | | - Eva E. Ávila
- Depto. de Biología
- DCNE
- Universidad de Guanajuato
- Guanajuato, México
| | | |
Collapse
|
38
|
Zhao D, Zhu J, Zhu Z, Song G, Wang H. Anisotropic hierarchical porous hydrogels with unique water loss/absorption and mechanical properties. RSC Adv 2014. [DOI: 10.1039/c4ra03472d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Anisotropic hierarchical porous poly(2-hydroxyethyl methacrylate-co-acrylamide) hydrogels show unidirectional solution diffusion, fast water loss/absorption and linear tensile stress–strain curves.
Collapse
Affiliation(s)
- Di Zhao
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875, China
| | - Jintang Zhu
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875, China
| | - Zhongcheng Zhu
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875, China
| | - Guoshan Song
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875, China
| | - Huiliang Wang
- Beijing Key Laboratory of Energy Conversion and Storage Materials
- College of Chemistry
- Beijing Normal University
- Beijing 100875, China
| |
Collapse
|
39
|
Enzymatically Synthesized Inorganic Polymers as Morphogenetically Active Bone Scaffolds. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 313:27-77. [DOI: 10.1016/b978-0-12-800177-6.00002-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
40
|
Inorganic Polymers: Morphogenic Inorganic Biopolymers for Rapid Prototyping Chain. BIOMEDICAL INORGANIC POLYMERS 2013; 54:235-59. [DOI: 10.1007/978-3-642-41004-8_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
41
|
Müller WEG, Wang X, Grebenjuk V, Diehl-Seifert B, Steffen R, Schloßmacher U, Trautwein A, Neumann S, Schröder HC. Silica as a morphogenetically active inorganic polymer. Biomater Sci 2013; 1:669-678. [DOI: 10.1039/c3bm00001j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
42
|
Biogenic Inorganic Polysilicates (Biosilica): Formation and Biomedical Applications. BIOMEDICAL INORGANIC POLYMERS 2013; 54:197-234. [DOI: 10.1007/978-3-642-41004-8_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|