1
|
Niziołek K, Słota D, Sobczak-Kupiec A. Polysaccharide-Based Composite Systems in Bone Tissue Engineering: A Review. MATERIALS (BASEL, SWITZERLAND) 2024; 17:4220. [PMID: 39274610 PMCID: PMC11396420 DOI: 10.3390/ma17174220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/13/2024] [Accepted: 08/18/2024] [Indexed: 09/16/2024]
Abstract
In recent years, a growing demand for biomaterials has been observed, particularly for applications in bone regenerative medicine. Bone tissue engineering (BTE) aims to develop innovative materials and strategies for repairing and regenerating bone defects and injuries. Polysaccharides, due to their biocompatibility, biodegradability as well as bioactivity, have emerged as promising candidates for scaffolds or composite systems in BTE. Polymers combined with bioactive ceramics can support osteointegration. Calcium phosphate (CaP) ceramics can be a broad choice as an inorganic phase that stimulates the formation of new apatite layers. This review provides a comprehensive analysis of composite systems based on selected polysaccharides used in bone tissue engineering, highlighting their synthesis, properties and applications. Moreover, the applicability of the produced biocomposites has been analyzed, as well as new trends in modifying biomaterials and endowing them with new functionalizations. The effects of these composites on the mechanical properties, biocompatibility and osteoconductivity were critically analyzed. This article summarizes the latest manufacturing methods as well as new developments in polysaccharide-based biomaterials for bone and cartilage regeneration applications.
Collapse
Affiliation(s)
- Karina Niziołek
- Cracow University of Technology, CUT Doctoral School, Faculty of Materials Engineering and Physics, Department of Materials Science, 37 Jana Pawła II Av., 31-864 Krakow, Poland
| | - Dagmara Słota
- Cracow University of Technology, CUT Doctoral School, Faculty of Materials Engineering and Physics, Department of Materials Science, 37 Jana Pawła II Av., 31-864 Krakow, Poland
| | - Agnieszka Sobczak-Kupiec
- Cracow University of Technology, Faculty of Materials Engineering and Physics, Department of Materials Science, 37 Jana Pawła II Av., 31-864 Krakow, Poland
| |
Collapse
|
2
|
Jiang P, Zhang Y, Hu R, Shi B, Zhang L, Huang Q, Yang Y, Tang P, Lin C. Advanced surface engineering of titanium materials for biomedical applications: From static modification to dynamic responsive regulation. Bioact Mater 2023; 27:15-57. [PMID: 37035422 PMCID: PMC10074421 DOI: 10.1016/j.bioactmat.2023.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023] Open
Abstract
Titanium (Ti) and its alloys have been widely used as orthopedic implants, because of their favorable mechanical properties, corrosion resistance and biocompatibility. Despite their significant success in various clinical applications, the probability of failure, degradation and revision is undesirably high, especially for the patients with low bone density, insufficient quantity of bone or osteoporosis, which renders the studies on surface modification of Ti still active to further improve clinical results. It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants. Therefore, it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration. This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical, physical and chemical treatments based on the formation mechanism of the modified coatings. Such conventional methods are able to improve bioactivity of Ti implants, but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues. Hence, beyond traditional static design, dynamic responsive avenues are then emerging. The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers. In short, this review surveys recent developments in the surface engineering of Ti materials, with a specific emphasis on advances in static to dynamic functionality, which provides perspectives for improving bioactivity and biocompatibility of Ti implants.
Collapse
Affiliation(s)
- Pinliang Jiang
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, 510640, China
- State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yanmei Zhang
- State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Ren Hu
- State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Bin Shi
- Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, China
| | - Lihai Zhang
- Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, China
| | - Qiaoling Huang
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, College of Physical Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Yun Yang
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials Research, College of Physical Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Peifu Tang
- Department of Orthopaedics, General Hospital of Chinese PLA, Beijing, 100853, China
| | - Changjian Lin
- State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| |
Collapse
|
3
|
Glowacka-Sobotta A, Ziental D, Czarczynska-Goslinska B, Michalak M, Wysocki M, Güzel E, Sobotta L. Nanotechnology for Dentistry: Prospects and Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2130. [PMID: 37513141 PMCID: PMC10383982 DOI: 10.3390/nano13142130] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
In the XXI century, application of nanostructures in oral medicine has become common. In oral medicine, using nanostructures for the treatment of dental caries constitutes a great challenge. There are extensive studies on the implementation of nanomaterials to dental composites in order to improve their properties, e.g., their adhesive strength. Moreover, nanostructures are helpful in dental implant applications as well as in maxillofacial surgery for accelerated healing, promoting osseointegration, and others. Dental personal care products are an important part of oral medicine where nanomaterials are increasingly used, e.g., toothpaste for hypersensitivity. Nowadays, nanoparticles such as macrocycles are used in different formulations for early cancer diagnosis in the oral area. Cancer of the oral cavity-human squamous carcinoma-is the sixth leading cause of death. Detection in the early stage offers the best chance at total cure. Along with diagnosis, macrocycles are used for photodynamic mechanism-based treatments, which possess many advantages, such as protecting healthy tissues and producing good cosmetic results. Application of nanostructures in medicine carries potential risks, like long-term influence of toxicity on body, which need to be studied further. The introduction and development of nanotechnologies and nanomaterials are no longer part of a hypothetical future, but an increasingly important element of today's medicine.
Collapse
Affiliation(s)
- Arleta Glowacka-Sobotta
- Chair and Department of Orthodontics and Temporomandibular Disorders, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznan, Poland
| | - Daniel Ziental
- Chair and Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Rokietnicka 3, 60-806 Poznan, Poland
| | - Beata Czarczynska-Goslinska
- Chair and Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland
| | - Maciej Michalak
- Chair and Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Rokietnicka 3, 60-806 Poznan, Poland
| | - Marcin Wysocki
- Chair and Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Rokietnicka 3, 60-806 Poznan, Poland
| | - Emre Güzel
- Department of Engineering Fundamental Sciences, Sakarya University of Applied Sciences, 54050 Sakarya, Türkiye
- Biomedical Technologies Application and Research Center (BIYOTAM), Sakarya University of Applied Sciences, 54050 Sakarya, Türkiye
| | - Lukasz Sobotta
- Chair and Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland
| |
Collapse
|
4
|
Addressing the Needs of the Rapidly Aging Society through the Development of Multifunctional Bioactive Coatings for Orthopedic Applications. Int J Mol Sci 2022; 23:ijms23052786. [PMID: 35269928 PMCID: PMC8911303 DOI: 10.3390/ijms23052786] [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: 02/15/2022] [Revised: 02/27/2022] [Accepted: 02/28/2022] [Indexed: 12/15/2022] Open
Abstract
The unprecedented aging of the world's population will boost the need for orthopedic implants and expose their current limitations to a greater extent due to the medical complexity of elderly patients and longer indwelling times of the implanted materials. Biocompatible metals with multifunctional bioactive coatings promise to provide the means for the controlled and tailorable release of different medications for patient-specific treatment while prolonging the material's lifespan and thus improving the surgical outcome. The objective of this work is to provide a review of several groups of biocompatible materials that might be utilized as constituents for the development of multifunctional bioactive coatings on metal materials with a focus on antimicrobial, pain-relieving, and anticoagulant properties. Moreover, the review presents a summary of medications used in clinical settings, the disadvantages of the commercially available products, and insight into the latest development strategies. For a more successful translation of such research into clinical practice, extensive knowledge of the chemical interactions between the components and a detailed understanding of the properties and mechanisms of biological matter are required. Moreover, the cost-efficiency of the surface treatment should be considered in the development process.
Collapse
|
5
|
Electrodeposited Hydroxyapatite-Based Biocoatings: Recent Progress and Future Challenges. COATINGS 2021. [DOI: 10.3390/coatings11010110] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hydroxyapatite has become an important coating material for bioimplants, following the introduction of synthetic HAp in the 1950s. The HAp coatings require controlled surface roughness/porosity, adequate corrosion resistance and need to show favorable tribological behavior. The deposition rate must be sufficiently fast and the coating technique needs to be applied at different scales on substrates having a diverse structure, composition, size, and shape. A detailed overview of dry and wet coating methods is given. The benefits of electrodeposition include controlled thickness and morphology, ability to coat a wide range of component size/shape and ease of industrial processing. Pulsed current and potential techniques have provided denser and more uniform coatings on different metallic materials/implants. The mechanism of HAp electrodeposition is considered and the effect of operational variables on deposit properties is highlighted. The most recent progress in the field is critically reviewed. Developments in mineral substituted and included particle, composite HAp coatings, including those reinforced by metallic, ceramic and polymeric particles; carbon nanotubes, modified graphenes, chitosan, and heparin, are considered in detail. Technical challenges which deserve further research are identified and a forward look in the field of the electrodeposited HAp coatings is taken.
Collapse
|
6
|
Shimada T, Yasui T, Yonese A, Yanagida T, Kaji N, Kanai M, Nagashima K, Kawai T, Baba Y. Mechanical Rupture-Based Antibacterial and Cell-Compatible ZnO/SiO 2 Nanowire Structures Formed by Bottom-Up Approaches. MICROMACHINES 2020; 11:E610. [PMID: 32599748 PMCID: PMC7345559 DOI: 10.3390/mi11060610] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 01/05/2023]
Abstract
There are growing interests in mechanical rupture-based antibacterial surfaces with nanostructures that have little toxicity to cells around the surfaces; however, current surfaces are fabricated via top-down nanotechnologies, which presents difficulties to apply for bio-surfaces with hierarchal three-dimensional structures. Herein, we developed ZnO/SiO2 nanowire structures by using bottom-up approaches and demonstrated to show mechanical rupture-based antibacterial activity and compatibility with human cells. When Escherichia coli were cultured on the surface for 24 h, over 99% of the bacteria were inactivated, while more than 80% of HeLa cells that were cultured on the surface for 24 h were still alive. This is the first demonstration of mechanical rupture-based bacterial rupture via the hydrothermally synthesized nanowire structures with antibacterial activity and cell compatibility.
Collapse
Affiliation(s)
- Taisuke Shimada
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
| | - Takao Yasui
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
- Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan;
| | - Akihiro Yonese
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
| | - Takeshi Yanagida
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan;
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan;
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan;
| | - Noritada Kaji
- Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masaki Kanai
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan;
| | - Kazuki Nagashima
- Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan;
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan;
| | - Tomoji Kawai
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan;
| | - Yoshinobu Baba
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
- Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;
- Institute of Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
| |
Collapse
|
7
|
Abstract
Dental implants are frequently used to support fixed or removable dental prostheses to replace missing teeth. The clinical success of titanium dental implants is owed to the exceptional biocompatibility and osseointegration with the bone. Therefore, the enhanced therapeutic effectiveness of dental implants had always been preferred. Several concepts for implant coating and local drug delivery had been developed during the last decades. A drug is generally released by diffusion-controlled, solvent-controlled, and chemical controlled methods. Although a range of surface modifications and coatings (antimicrobial, bioactive, therapeutic drugs) have been explored for dental implants, it is still a long way from designing sophisticated therapeutic implant surfaces to achieve the specific needs of dental patients. The present article reviews various interdisciplinary aspects of surface coatings on dental implants from the perspectives of biomaterials, coatings, drug release, and related therapeutic effects. Additionally, the various types of implant coatings, localized drug release from coatings, and how released agents influence the bone–implant surface interface characteristics are discussed. This paper also highlights several strategies for local drug delivery and their limitations in dental implant coatings as some of these concepts are yet to be applied in clinical settings due to the specific requirements of individual patients.
Collapse
|
8
|
Cierech M, Wojnarowicz J, Kolenda A, Krawczyk-Balska A, Prochwicz E, Woźniak B, Łojkowski W, Mierzwińska-Nastalska E. Zinc Oxide Nanoparticles Cytotoxicity and Release from Newly Formed PMMA-ZnO Nanocomposites Designed for Denture Bases. NANOMATERIALS 2019; 9:nano9091318. [PMID: 31540147 PMCID: PMC6781076 DOI: 10.3390/nano9091318] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 01/22/2023]
Abstract
The goal of the study was to investigate the level of zinc oxide nanoparticles (ZnO NPs) release from polymethyl methacrylate (PMMA)-ZnO nanocomposites (2.5%, 5%, and 7.5% w/w), as well as from the ZnO NPs layer produced on pure PMMA, and the impact of the achieved final ZnO NPs concentration on cytotoxicity, before the potential use as an alternative material for denture bases. The concentration of ZnO nanoparticles released to the aqueous solution of Zn2+ ions was assessed using optical emission spectrometry with inductively coupled plasma (ICP-OES). In the control group (pure PMMA), the released mean for ZnO was 0.074 mg/L and for individual nanocomposites at concentrations of 2.5%, 5%, and 7.5% was 2.281 mg/L, 2.143 mg/L, and 3.512 mg/L, respectively. The median for the ZnO NPs layer produced on PMMA was 4.878 mg/L. In addition, in vitro cytotoxicity of ZnO NPs against the human HeLa cell line was determined through the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. The cytotoxicity studies demonstrate that ZnO nanoparticles in the concentrations up to 20 mg/L have no adverse effect on HeLa cells. When compared with the released and cytotoxic concentrations of ZnO NPs, it can be expected that ZnO released from dental prostheses to the oral cavity environment will have no cytotoxic effect on host cells.
Collapse
Affiliation(s)
- Mariusz Cierech
- Department of Prosthodontics, Medical University of Warsaw, 02-006 Warsaw, Poland.
| | - Jacek Wojnarowicz
- Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw, Poland.
| | - Adam Kolenda
- Department of Prosthodontics, Medical University of Warsaw, 02-006 Warsaw, Poland.
| | - Agata Krawczyk-Balska
- Department of Applied Microbiology, Biological and Chemical Research Centre, Faculty of Biology, University of Warsaw, 02-089 Warsaw, Poland.
| | - Emilia Prochwicz
- Department of Applied Microbiology, Biological and Chemical Research Centre, Faculty of Biology, University of Warsaw, 02-089 Warsaw, Poland.
| | - Bartosz Woźniak
- Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw, Poland.
| | - Witold Łojkowski
- Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw, Poland.
| | | |
Collapse
|
9
|
Yang Y, Wang H, Zhu JC, Shao YF, Bai FJ, Chen XM, Li X, Guo M, Shao Z, Zhang KQ. Silk-Fibroin-Assisted Cathodic Electrolytic Deposition of Calcium Phosphate for Biomedical Applications. ACS Biomater Sci Eng 2019; 5:4302-4310. [DOI: 10.1021/acsbiomaterials.9b00207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | - Hui Wang
- Jiangsu Industrial Technology Research Institute of Textile & Silk, Nantong Textile & Silk Industrial Technology Research Institute, Nantong, PR China
| | | | | | | | | | | | | | - Zengwu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical Collage, Huazhong University of Science and Technology, Wuhan 430022, PR China
| | - Ke-Qin Zhang
- Jiangsu Industrial Technology Research Institute of Textile & Silk, Nantong Textile & Silk Industrial Technology Research Institute, Nantong, PR China
| |
Collapse
|
10
|
CaP Coating and Low-Level Laser Therapy to Stimulate Early Bone Formation and Improve Fixation of Rough Threaded Implants. IMPLANT DENT 2018; 27:660-666. [DOI: 10.1097/id.0000000000000824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
11
|
|
12
|
Pokrowiecki R, Pałka K, Mielczarek A. Nanomaterials in dentistry: a cornerstone or a black box? Nanomedicine (Lond) 2018; 13:639-667. [DOI: 10.2217/nnm-2017-0329] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Aim: The studies on tooth structure provided basis for nanotechnology-based dental treatment approaches known as nanodentistry which aims at detection and treatment of oral pathologies, such as dental caries and periodontal diseases, insufficiently being treated by conventional materials or drugs. This review aims at defining the role of nanodentistry in the medical area, its potential and hazards. Materials & methods: To validate these issues, current literature on nanomaterials for dental applications was critically reviewed. Results: Nanomaterials for teeth restoration, bone regeneration and oral implantology exhibit better mechanical properties and provide more efficient esthetic outcome. However, still little is known about influence of long-term function of such biomaterials in the living organism. Conclusion: As application of nanomaterials in industry and medical-related sciences is still expanding, more information is needed on how such nano-dental materials may interfere with oral cavity, GI tract and general health.
Collapse
Affiliation(s)
- Rafał Pokrowiecki
- Department of Head & Neck Surgery – Maxillofacial Surgery, Otolaryngology & Ophthalmology, Prof Stanislaw Popowski Voivoid Children Hospital, Żołnierska 18 A10-561 Olsztyn, Poland
| | - Krzysztof Pałka
- Faculty of Mechanical Engineering, Lublin University of Technology, Lublin, Poland
| | - Agnieszka Mielczarek
- Department of Conservative Dentistry, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|