1
|
Singh H, Yadav I, Sheikh WM, Dan A, Darban Z, Shah SA, Mishra NC, Shahabuddin S, Hassan S, Bashir SM, Dhanka M. Dual cross-linked gellan gum/gelatin-based multifunctional nanocomposite hydrogel scaffold for full-thickness wound healing. Int J Biol Macromol 2023; 251:126349. [PMID: 37591426 DOI: 10.1016/j.ijbiomac.2023.126349] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/31/2023] [Accepted: 08/13/2023] [Indexed: 08/19/2023]
Abstract
Biological macromolecules are excellent materials for wound dressing owing to their similar structure to the extracellular matrix and adjustable physicochemical properties. This research focuses on fabricating biological macromolecule-based hydrogel with desirable antibacterial, antioxidant, controlled drug release, cytocompatibility, and wound healing properties. Herein, different concentrations of nanoceria (NC) and flurbiprofen (FLU) drug-loaded gellan gum/gelatin (GG/Ge) based dual crosslinked (Ionic and EDC/NHS coupling) hydrogels were engineered. All fabricated hydrogels were hydrophilic, biodegradable, good strength, porous, antioxidant, hemocompatible and cytocompatible. Among all, hydrogel loaded with 500 μg/ml NC (GG/Ge/NC@FLU) exhibited desirable antioxidant, antibacterial (killed Staphylococcus aureus and Escherichia coli within 12 h), hemocompatible, cytocompatible, supports oxidative-stressed L929 cell growth and acted as a controlled release matrix for FLU, following Fickian diffusion, Peppas Sahlin and Korsmeyer-Peppas drug release models. Furthermore, nanocomposite hydrogel (GG/Ge/NC@FLU)-treated wounds of rats on day 14 demonstrated significantly higher collagen synthesis, nearly 100 % wound contractions, and efficiently decreased the expression of TNF-α and IL-1 while increasing the production of IL-10 and TNF-ß3, indicating antiinflammatory activity, and effectively reduced the expression of VEGF gene indicating effective angiogenesis than all other controls. In conclusion, the fabricated multifunctional GG/Ge/NC@FLU nanocomposite hydrogel shows promising potential for effectively treating full-thickness wound healing in a rat model.
Collapse
Affiliation(s)
- Hemant Singh
- Biological Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India
| | - Indu Yadav
- Polymer and Process Engineering, Indian Institute of Technology Roorkee, Uttarakhand, India
| | - Wajid Mohammad Sheikh
- Biochemistry & Molecular Biology Lab, Division of Veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu and Kashmir, India
| | - Aniruddha Dan
- Biological Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India
| | - Zenab Darban
- Department of Chemistry, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India
| | - Showkat Ahmad Shah
- Division of Veterinary Pathology, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu and Kashmir, India
| | - Narayan Chandra Mishra
- Polymer and Process Engineering, Indian Institute of Technology Roorkee, Uttarakhand, India.
| | - Syed Shahabuddin
- Department of Chemistry, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India
| | - Shabir Hassan
- Department of Biology, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Showkeen Muzamil Bashir
- Biochemistry & Molecular Biology Lab, Division of Veterinary Biochemistry, Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu and Kashmir, India.
| | - Mukesh Dhanka
- Biological Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India.
| |
Collapse
|
2
|
Zinc oxide loaded chitosan-elastin-sodium alginate nanocomposite gel using freeze gelation for enhanced adipose stem cell proliferation and antibacterial properties. Int J Biol Macromol 2023; 233:123519. [PMID: 36758760 DOI: 10.1016/j.ijbiomac.2023.123519] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/26/2023] [Accepted: 01/29/2023] [Indexed: 02/10/2023]
Abstract
Hydrogels have been the material of choice for regenerative medicine applications due to their biocompatibility that can facilitate cellular attachment and proliferation. The present study aimed at constructing a porous hydrogel composite scaffold (chitosan, sodium alginate and elastin) for the repair of chronic skin wounds. Chitosan-based hydrogel incorporating varying concentrations of zinc oxide nanoparticles i.e. ZnO-NPs (0, 0.001, 0.01, 0.1 and 1 % w/w) as the antimicrobial agent tested against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) exhibited good antibacterial activities. ZnO-NPs were characterized by UV visible spectroscopy, Scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Fabricated gels were characterized by SEM analysis, FTIR, XRD, swelling ratio, degradation behavior and controlled release kinetics of ZnO-NPs. In vitro cytocompatibility of the composite was investigated using human adipose stem cells (ADSCs) by MTT and lactate dehydrogenase (LDH) assay, further assessed by SEM analysis and PKH26 staining. The SEM and XRD analysis confirmed the successful loading of ZnO-NPs into these scaffolds. Fluorescence PKH26 stained images and SEM analysis of ADSCs seeded scaffolds revealed biocompatible nature. The findings suggested that the developed composite gels have potential clinically for tissue engineering and chronic wound treatment.
Collapse
|
3
|
Katiyar S, Singh D, Kumari S, Srivastava P, Mishra A. Novel strategies for designing regenerative skin products for accelerated wound healing. 3 Biotech 2022; 12:316. [PMID: 36276437 PMCID: PMC9547767 DOI: 10.1007/s13205-022-03331-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/23/2022] [Indexed: 11/01/2022] Open
Abstract
Healthy skin protects from pathogens, water loss, ultraviolet rays, and also maintains homeostasis conditions along with sensory perceptions in normal circumstances. Skin wound healing mechanism is a multi-phased biodynamic process that ultimately triggers intercellular and intracellular mechanisms. Failure to implement the normal and effective healing process may result in chronic injuries and aberrant scarring. Chronic wounds lead to substantial rising healthcare expenditure, and innovative methods to diagnose and control severe consequences are urgently needed. Skin tissue engineering (STE) has achieved several therapeutic accomplishments during the last few decades, demonstrating tremendous development. The engineered skin substitutes provide instant coverage for extensive wounds and facilitate the prevention of microbial infections and fluid loss; furthermore, they help in fighting inflammation and allow rapid neo-tissue formation. The current review primarily focused on the wound recovery and restoration process and the current conditions of STE with various advancements and complexities associated with different strategies such as cell sources, biopolymers, innovative fabrication techniques, and growth factors delivery systems.
Collapse
Affiliation(s)
- Soumya Katiyar
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
| | - Divakar Singh
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
| | - Shikha Kumari
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
| | - Pradeep Srivastava
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
| | - Abha Mishra
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
| |
Collapse
|
4
|
Andleeb A, Mehmood A, Tariq M, Butt H, Ahmed R, Andleeb A, Ghufran H, Ramzan A, Ejaz A, Malik K, Riazuddin S. Hydrogel patch with pretreated stem cells accelerates wound closure in diabetic rats. BIOMATERIALS ADVANCES 2022; 142:213150. [PMID: 36306556 DOI: 10.1016/j.bioadv.2022.213150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/29/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Delay in wound healing is a diabetes mellites resulting disorder causing persistent microbial infections, pain, and poor quality of life. This disorder is treated by several strategies using natural biomaterials, growth factors and stem cells molded into various scaffolds which possess the potential to accelerate the closure of impaired diabetic wounds. In this study, we developed a hydrogel patch using chitosan (CS) and polyethylene glycol (PEG) with laden bone marrow-derived mesenchymal stem cells (BMSCs) that were pretreated with fibroblast growth factor 21 (FGF21). The developed hydrogel patches were characterized by scanning electron microscopy and fourier transform infrared (FTIR) spectroscopy. After studying the swelling behavior, growth factor (FGF21) was used to modulate BMSC in the hyperglycemic environment. Later, FGF21 treated BMSC were embedded in CS/PEG hydrogel patch and their wound closure effect was assessed in diabetic rats. The results showed that CS/PEG hydrogel patches have good biocompatibility and possess efficient BMSC recruiting properties. The application of CS/PEG hydrogel patches accelerated wound closure in diabetic rats as compared to the control groups. However, the use of FGF21 pretreated BMSCs laded CS/PEG hydrogel patches further increased the therapeutic efficacy of wound closure in diabetic rats. This study demonstrated that the application of a hydrogel patch of CS/PEG with FGF21 pretreated BMSCs improves diabetic wound healing, but further studies are needed on larger animals before the use of these dressings in clinical trials.
Collapse
Affiliation(s)
- Anisa Andleeb
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan; Department of Biotechnology, Faculty of Natural and Applied Sciences, Mirpur University of Science and Technology, Mirpur 10250, AJK, Pakistan
| | - Azra Mehmood
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan
| | - Muhammad Tariq
- Department of Biotechnology, Faculty of Natural and Applied Sciences, Mirpur University of Science and Technology, Mirpur 10250, AJK, Pakistan
| | - Hira Butt
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan
| | - Rashid Ahmed
- Department of Biotechnology, Faculty of Natural and Applied Sciences, Mirpur University of Science and Technology, Mirpur 10250, AJK, Pakistan; Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana Champaign, IL, USA
| | - Aneeta Andleeb
- School of Biochemistry & Biotechnology, University of the Punjab, Lahore 54590, Pakistan
| | - Hafiz Ghufran
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan
| | - Amna Ramzan
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan
| | - Asim Ejaz
- Adipose Stem Cells Center, Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, USA
| | - Kausar Malik
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Bank Road, Lahore, Pakistan; Jinnah Burn and Reconstructive Surgery Centre, Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan.
| |
Collapse
|
5
|
Suo L, Xue Z, Wang P, Wu H, Chen Y, Shen J. Improvement of osteogenic properties using a 3D-printed graphene oxide/hyaluronic acid/chitosan composite scaffold. J BIOACT COMPAT POL 2022. [DOI: 10.1177/08839115221104072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oral and maxillofacial tumors, trauma and infections are the main causes of jaw defects, whose clinical treatment is very complicated. With the development of biological tissue engineering, many biological materials have been widely used in various fields of stomatology, and they play a very important role in the repair and replacement of maxillofacial bone defects. In this study, we intended to prepare a graphene oxide/hyaluronic acid/chitosan (GO/HA/CS) composite hydrogel with different mass ratios of GO: 0.1% (0.1% GO/HA/CS), 0.25% (0.25% GO/HA/CS), 0.5% (0.5% GO/HA/CS), and 1% (1% GO/HA/CS), prepare it into a multilayered and stable composite scaffold through 3D-printing technology, observe the surface morphology of the composite scaffold through scanning electron microscopy (SEM), and then test its physical and chemical properties, mechanical properties, water swelling rate, in vitro degradation and other material properties. Moreover, the biological performance of the GO/HA/CS composite scaffold was studied through experiments, such as cell morphology observation, cell adhesion, cell proliferation, and live-dead cell staining. The results showed that through chemical cross-linking and 3D-printing technology, a porous (pore size: 450–580 μm) and multilayered GO/HA/CS biological scaffold could be successfully constructed, and its surface was an interconnected microporous structure, and the porosity decreased (94%−40%) gradually with the increase of GO. Meanwhile, with the change in GO concentration, some mechanical properties of the scaffold could be improved, such as water swelling rate, degradation rate, and elastic modulus. In addition, the composite scaffold with the appropriate amount of GO had almost no cytotoxicity and could promote cell growth and proliferation, especially 0.25% GO/HA/CS composite scaffold. Consequently, the 0.25% GO/HA/CS composite scaffold had excellent biological material properties and good biocompatibility with osteoblasts, which may provide a new idea for the repair of jaw defects.
Collapse
Affiliation(s)
- Lai Suo
- Department of International VIP Dental Clinic, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin, China
| | - Zhijun Xue
- Department II of Endodontics, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin, China
| | - Puyu Wang
- Department II of Endodontics, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin, China
| | - Hongshan Wu
- School of Medicine, Nankai University, Tianjin, China
| | - Yao Chen
- Department II of Endodontics, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin, China
| | - Jing Shen
- Department of International VIP Dental Clinic, Tianjin Stomatological Hospital, School of Medicine, Nankai University, Tianjin, China
| |
Collapse
|
6
|
Zubairi W, Zehra M, Mehmood A, Iqbal F, Badar R, Hasan A, Yar M. Evaluation of angiogenic potential of heparin and thyroxine releasing wound dressings. INT J POLYM MATER PO 2021. [DOI: 10.1080/00914037.2021.1960335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Waliya Zubairi
- Interdisciplinary Research Center in Biomedical Materials, COMSATS University Islamabad Lahore Campus, Lahore, Pakistan
- Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Pakistan
| | - Mubashra Zehra
- Interdisciplinary Research Center in Biomedical Materials, COMSATS University Islamabad Lahore Campus, Lahore, Pakistan
- National Center of Excellence in Molecular Biology (CEMB), University of the Punjab, Lahore, Pakistan
| | - Azra Mehmood
- National Center of Excellence in Molecular Biology (CEMB), University of the Punjab, Lahore, Pakistan
| | - Farasat Iqbal
- Interdisciplinary Research Center in Biomedical Materials, COMSATS University Islamabad Lahore Campus, Lahore, Pakistan
| | - Rida Badar
- Interdisciplinary Research Center in Biomedical Materials, COMSATS University Islamabad Lahore Campus, Lahore, Pakistan
| | - Anwarul Hasan
- Department of Mechanical and Industrial Engineering, College of Engineering, Qatar University, Doha, Qatar
- Biomedical Research Center, Qatar University, Doha, Qatar
| | - Muhammad Yar
- Interdisciplinary Research Center in Biomedical Materials, COMSATS University Islamabad Lahore Campus, Lahore, Pakistan
| |
Collapse
|
7
|
Castillo-Henríquez L, Castro-Alpízar J, Lopretti-Correa M, Vega-Baudrit J. Exploration of Bioengineered Scaffolds Composed of Thermo-Responsive Polymers for Drug Delivery in Wound Healing. Int J Mol Sci 2021; 22:1408. [PMID: 33573351 PMCID: PMC7866792 DOI: 10.3390/ijms22031408] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/13/2021] [Accepted: 01/27/2021] [Indexed: 02/06/2023] Open
Abstract
Innate and adaptive immune responses lead to wound healing by regulating a complex series of events promoting cellular cross-talk. An inflammatory response is presented with its characteristic clinical symptoms: heat, pain, redness, and swelling. Some smart thermo-responsive polymers like chitosan, polyvinylpyrrolidone, alginate, and poly(ε-caprolactone) can be used to create biocompatible and biodegradable scaffolds. These processed thermo-responsive biomaterials possess 3D architectures similar to human structures, providing physical support for cell growth and tissue regeneration. Furthermore, these structures are used as novel drug delivery systems. Locally heated tumors above the polymer lower the critical solution temperature and can induce its conversion into a hydrophobic form by an entropy-driven process, enhancing drug release. When the thermal stimulus is gone, drug release is reduced due to the swelling of the material. As a result, these systems can contribute to the wound healing process in accelerating tissue healing, avoiding large scar tissue, regulating the inflammatory response, and protecting from bacterial infections. This paper integrates the relevant reported contributions of bioengineered scaffolds composed of smart thermo-responsive polymers for drug delivery applications in wound healing. Therefore, we present a comprehensive review that aims to demonstrate these systems' capacity to provide spatially and temporally controlled release strategies for one or more drugs used in wound healing. In this sense, the novel manufacturing techniques of 3D printing and electrospinning are explored for the tuning of their physicochemical properties to adjust therapies according to patient convenience and reduce drug toxicity and side effects.
Collapse
Affiliation(s)
- Luis Castillo-Henríquez
- National Laboratory of Nanotechnology (LANOTEC), National Center for High Technology (CeNAT), 1174-1200 San José, Costa Rica;
- Physical Chemistry Laboratory, Faculty of Pharmacy, University of Costa Rica, 11501-2060 San José, Costa Rica
| | - Jose Castro-Alpízar
- Laboratory of Pharmaceutical Technology, Faculty of Pharmacy, University of Costa Rica, 11501-2060 San José, Costa Rica;
| | - Mary Lopretti-Correa
- Nuclear Research Center, Faculty of Science, Universidad de la República (UdelaR), 11300 Montevideo, Uruguay;
| | - José Vega-Baudrit
- National Laboratory of Nanotechnology (LANOTEC), National Center for High Technology (CeNAT), 1174-1200 San José, Costa Rica;
- Laboratory of Polymers (POLIUNA), Chemistry School, National University of Costa Rica, 86-3000 Heredia, Costa Rica
| |
Collapse
|
8
|
Ramanunny AK, Wadhwa S, Gulati M, Singh SK, Kapoor B, Dureja H, Chellappan DK, Anand K, Dua K, Khursheed R, Awasthi A, Kumar R, Kaur J, Corrie L, Pandey NK. Nanocarriers for treatment of dermatological diseases: Principle, perspective and practices. Eur J Pharmacol 2020; 890:173691. [PMID: 33129787 DOI: 10.1016/j.ejphar.2020.173691] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 10/23/2022]
Abstract
Skin diseases are the fourth leading non-fatal skin conditions that act as a burden and affect the world economy globally. This condition affects the quality of a patient's life and has a pronounced impact on both their physical and mental state. Treatment of these skin conditions with conventional approaches shows a lack of efficacy, long treatment duration, recurrence of conditions, systemic side effects, etc., due to improper drug delivery. However, these pitfalls can be overcome with the applications of nanomedicine-based approaches that provide efficient site-specific drug delivery at the target site. These nanomedicine-based strategies are evolved as potential treatment opportunities in the form of nanocarriers such as polymeric and lipidic nanocarriers, nanoemulsions along with emerging others viz. carbon nanotubes for dermatological treatment. The current review focuses on challenges faced by the existing conventional treatments along with the topical therapeutic perspective of nanocarriers in treating various skin diseases. A total of 213 articles have been reviewed and the application of different nanocarriers in treating various skin diseases has been explained in detail through case studies of previously published research works. The toxicity related aspects of nanocarriers are also discussed.
Collapse
Affiliation(s)
| | - Sheetu Wadhwa
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Monica Gulati
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Sachin Kumar Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India.
| | - Bhupinder Kapoor
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Harish Dureja
- Department of Pharmaceutical Sciences, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Dinesh Kumar Chellappan
- School of Pharmacy, International Medical University, Bukit Jalil, 57000, Kuala Lumpur, Malaysia
| | - Krishnan Anand
- Department of Chemical Pathology, School of Pathology, Faculty of Health Sciences and National Health Laboratory Service, University of the Free State, Bloemfontein, South Africa
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Rubiya Khursheed
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Ankit Awasthi
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Rajan Kumar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Jaskiran Kaur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Leander Corrie
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Narendra Kumar Pandey
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India
| |
Collapse
|