1
|
Moore JV, Wylie MP, Andrews GP, McCoy CP. Photosensitiser-incorporated microparticles for photodynamic inactivation of bacteria. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 241:112671. [PMID: 36870247 DOI: 10.1016/j.jphotobiol.2023.112671] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/27/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023]
Abstract
Antimicrobial resistance is an ever-growing global concern, making the development of alternative antimicrobial agents and techniques an urgent priority to protect public health. Antimicrobial photodynamic therapy (aPDT) is one such promising alternative, which harnesses the cytotoxic action of reactive oxygen species (ROS) generated upon irradiation of photosensitisers (PSs) with visible light to destroy microorganisms. In this study we report a convenient and facile method to produce highly photoactive antimicrobial microparticles, exhibiting minimal PS leaching, and examine the effect of particle size on antimicrobial activity. A ball milling technique produced a range of sizes of anionic p(HEMA-co-MAA) microparticles, providing large surface areas available for electrostatic attachment of the cationic PS, Toluidine Blue O (TBO). The TBO-incorporated microparticles showed a size-dependent effect on antimicrobial activity, with a decrease in microparticle size resulting in an increase in the bacterial reductions achieved when irradiated with red light. The >6 log10Pseudomonas aeruginosa and Staphylococcus aureus reductions (>99.9999%) achieved within 30 and 60 min, respectively, by TBO-incorporated >90 μm microparticles were attributed to the cytotoxic action of the ROS generated by TBO molecules bound to the microparticles, with no PS leaching from these particles detected over this timeframe. TBO-incorporated microparticles capable of significantly reducing the bioburden of solutions with short durations of low intensity red light irradiation and minimal leaching present an attractive platform for various antimicrobial applications.
Collapse
Affiliation(s)
- Jessica V Moore
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Matthew P Wylie
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Gavin P Andrews
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
| |
Collapse
|
2
|
Xiang Y, Jin R, Zhang Y, Li K, Liu G, Song X, Wang Y, Nie Y. Foldable Glistening-Free Acrylic Intraocular Lens Biomaterials with Dual-Side Heterogeneous Surface Modification for Postoperative Endophthalmitis and Posterior Capsule Opacification Prophylaxis. Biomacromolecules 2021; 22:3510-3521. [PMID: 34288655 DOI: 10.1021/acs.biomac.1c00582] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hydrophobic acrylic intraocular lenses (IOLs) are widely used in cataract treatment for posterior capsule opacification (PCO) prophylaxis. However, undesired glistening and postoperative endophthalmitis are two major potential risks. Hence, a series of poly(2-phenoxyethyl methacrylate-co-2-phenoxyethyl acrylate-co-2-ethylhexyl methacrylate) (PPPE) acrylic IOL materials were synthesized for "glistening-free" optimization. The selected PPPE with 2% 2-ethylhexyl methacrylate showed excellent optical, foldable, and thermomechanical properties. The anterior surface of PPPE was coated with polydopamine followed by gentamycin conjugation (PDA/GS). It inhibited bacterial adhesion by 74% and decreased the biofilm thickness by 87%. In inflammatory mimicking conditions, bacterial proliferation was restrained, with acidic-dependent GS release behavior. The surface of PPPE toward the posterior capsule remained hydrophobic. It was conducive to human lens epithelial cell adhesion, collagen IV and fibronectin adsorption, and the following "sealed sandwich structure" formation. In summary, the PPPE with a dual-side heterogeneous surface displayed good application prospects in postoperative endophthalmitis and PCO prevention.
Collapse
Affiliation(s)
- Yang Xiang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610065, China
| | - Rongrong Jin
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610065, China
| | - Ying Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610065, China
| | - Kaijun Li
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Gongyan Liu
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Xu Song
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610065, China.,NMPA Key Laboratory for Quality Research and Control of Tissue Regenerative Biomaterial & Institute of Regulatory Science for Medical Devices & NMPA Research Base of Regulatory Science for Medical Devices, Sichuan University, Chengdu 610065, China
| | - Yunbing Wang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610065, China
| | - Yu Nie
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610065, China
| |
Collapse
|
3
|
López-Fernández AM, Muñoz Resta I, de Llanos R, Galindo F. Photodynamic Inactivation of Pseudomonas aeruginosa by PHEMA Films Loaded with Rose Bengal: Potentiation Effect of Potassium Iodide. Polymers (Basel) 2021; 13:2227. [PMID: 34300985 PMCID: PMC8309320 DOI: 10.3390/polym13142227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 12/19/2022] Open
Abstract
Four formulations have been used to produce different poly(2-hydroxyethyl methacrylate) (PHEMA) thin films, containing singlet oxygen photosensitizer Rose Bengal (RB). The polymers have been characterized employing Thermogravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and UV-vis Absorption Spectroscopy. When irradiated with white light (400-700 nm) films generated singlet oxygen (1O2), as demonstrated by the reactivity with 1O2 trap 9,10-dimethylanthracene (DMA). Material with the highest RB loading (polymer A4, 835 nmol RB/g polymer) was able to perform up to ten cycles of DMA oxygenation reactions at high conversion rates (ca. 90%). Polymer A4 was also able to produce the complete eradication of a Pseudomonas aeruginosa planktonic suspension of 8 log10 CFU/mL, when irradiated with white light (total dose 72 J/cm2). The antimicrobial photodynamic effect was remarkably enhanced by adding potassium iodide (100 mM). In such conditions the complete bacterial reduction occurred with a total light dose of 24 J/cm2. Triiodide anion (I3-) generation was confirmed by UV-vis absorption spectroscopy. This species was detected inside the PHEMA films after irradiation and at concentrations ca. 1 M. The generation of this species and its retention in the matrix imparts long-lasting bactericidal effects to the RB@PHEMA polymeric hydrogels. The polymers here described could find potential applications in the medical context, when optimized for their use in everyday objects, helping to prevent bacterial contagion by contact with surfaces.
Collapse
Affiliation(s)
- Ana M. López-Fernández
- Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Av. V. Sos Baynat s/n, 12071 Castellón, Spain; (A.M.L.-F.); (I.M.R.)
| | - Ignacio Muñoz Resta
- Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Av. V. Sos Baynat s/n, 12071 Castellón, Spain; (A.M.L.-F.); (I.M.R.)
| | - Rosa de Llanos
- Unidad Predepartamental de Medicina, Universitat Jaume I, Av. V. Sos Baynat s/n, 12071 Castellón, Spain
| | - Francisco Galindo
- Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Av. V. Sos Baynat s/n, 12071 Castellón, Spain; (A.M.L.-F.); (I.M.R.)
| |
Collapse
|
4
|
Belosludov RV, Nevonen DE, Nemykin VN. Accurate Prediction of the Excited States in the Fully Conjugated Porphyrin Tapes across the Full Spectral Range: A Story of the Interplay between π-π* and Intramolecular Charge-Transfer Transitions in Soft Chromophores. J Phys Chem A 2021; 125:2480-2491. [PMID: 33734683 DOI: 10.1021/acs.jpca.1c00217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The ability of density functional theory (DFT) and time-dependent DFT (TDDFT) methods for the accurate prediction of the energies and oscillator strengths of the excited states in a series of fully conjugated meso-meso β-β β-β triple-linked porphyrin oligomers (porphyrin tapes 2-12) was probed in the gas phase and solution using several exchange-correlation functionals. It was demonstrated that the use of the hybrid B3LYP functional provides a good compromise for the accurate prediction of the localized π-π* and intramolecular charge-transfer transitions, thus allowing confident interpretation of the UV-vis-NIR spectra of porphyrin oligomers. The TDDFT-based sum-over-state (SOS) calculations for the porphyrin tape dimer 2 and trimer 3 as well as parent monomer 1 correctly predicted the signs and shapes of the magnetic circular dichroism (MCD) signals in the low-energy region of the spectra.
Collapse
Affiliation(s)
- Rodion V Belosludov
- Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Dustin E Nevonen
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Victor N Nemykin
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.,Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| |
Collapse
|
5
|
Wylie MP, Irwin NJ, Howard D, Heydon K, McCoy CP. Hot-melt extrusion of photodynamic antimicrobial polymers for prevention of microbial contamination. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 214:112098. [PMID: 33276276 DOI: 10.1016/j.jphotobiol.2020.112098] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 01/31/2023]
Abstract
Infectious disease outbreaks within healthcare facilities can exacerbate patient illness and, in some cases, can be fatal. Contaminated surfaces and medical devices can act as a reservoir for transmission of pathogens and have been linked to the rising incidence of healthcare-acquired infections. Antimicrobial surfaces can reduce microbial contamination and transmission and have emerged as a crucial component in healthcare infection control in recent years. The aim of this study was to manufacture antimicrobial polymer surfaces containing the photosensitiser, toluidine blue O (TBO), using hot-melt extrusion (HME). Several concentrations of TBO were combined with a range of medically relevant polymers via HME. TBO-polymer extrudates displayed no significant differences in thermal properties and surface wettability relative to non-loaded polymers. Minimal leaching of TBO from the surface was confirmed through in vitro release studies. Antibacterial activity was observed to vary according to the polymer and concentration of incorporated TBO, with PEBAX® polymers modified with 0.1% w/w TBO demonstrating promising reductions of >99.9% in viable bacterial adherence of a range of common nosocomial pathogens, including Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii and Escherichia coli. This study demonstrates the use of HME as a facile alternative method to common encapsulation strategies for the production of light-activated antimicrobial polymer surfaces. This method can be easily translated to large-scale manufacture and, in addition, the polymers constitute promising antimicrobial base materials for the rapidly growing additive manufacturing industries.
Collapse
Affiliation(s)
- Matthew P Wylie
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Nicola J Irwin
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - David Howard
- IPC - Innovative Polymer Compounds, Midlands Gateway Business Park, Streamstown Road, Kilbeggan, Co. Westmeath, Ireland
| | - Katie Heydon
- IPC - Innovative Polymer Compounds, Midlands Gateway Business Park, Streamstown Road, Kilbeggan, Co. Westmeath, Ireland
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
| |
Collapse
|
6
|
Strokov K, Galstyan A. Chitosan‐Silicon Phthalocyanine Conjugate as Effective Photo‐Functional Hydrogel for Tracking and Killing of Bacteria. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001363] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Konstantin Strokov
- Center for Soft Nanoscience Westfälische Wilhelms‐Universität Münster Busso‐Peus‐Straße 10 48149 Münster Germany
| | - Anzhela Galstyan
- Center for Soft Nanoscience Westfälische Wilhelms‐Universität Münster Busso‐Peus‐Straße 10 48149 Münster Germany
| |
Collapse
|
7
|
Xiang Y, Zou M, Zhang Y, Jin R, Nie Y. Drug-loaded and Blue-ray Filtered Hydrogel as a Potential Intraocular Lens for Cataract Treatment. Pharm Nanotechnol 2020; 8:302-312. [PMID: 32167435 DOI: 10.2174/2211738508666200313144112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/21/2020] [Accepted: 02/25/2020] [Indexed: 02/08/2023]
Abstract
Background:
Indomethacin (IND) is a class of non-steroidal, anti-inflammatory
drugs, which is used to treat various kinds of ocular inflammation, and has been reported to
prevent posterior capsule opacification (PCO) by inhibiting the mitosis and collagen synthesis
of human lens epithelial cells (LECs). In addition, the specific absorption spectrum of indomethacin
shows the effect of absorbing short-wavelength blue-violet light.
Objective:
We prepared an indomethacin-loaded hydrogel as a potential intraocular lens (IOLs)
material to prevent endophthalmitis, PCO and filter harmful blue light.
Methods:
Indomethacin prodrugs (HEMA-IND) (HI) were prepared by esterification of indomethacin
and 2-hydroxyethyl methacrylate (HEMA), and poly (HEMA-co-MAA-co-MMA-co-
HI) (HAMI) hydrogels were prepared by free-radical polymerization of 2-hydroxyethyl methacrylate
(HEMA), methyl methacrylate (MMA), methacrylic acid (MAA) and HI. The physical
and chemical properties of obtained hydrogel were detected, including optical, morphology,
thermomechanical and surface properties, equilibrium water content, drug release behaviors and
cytotoxicity.
Results:
HAMI hydrogels can filter harmful short-wavelength blue light and show other necessary
properties like visible light transparency, glass transition temperatures, mechanical
strength, and biocompatibility for making intraocular lenses. Meanwhile, MAA increases the
hydrophilicity of the hydrogels, resulting in a lower water contact angle and controllable drug
release from the hydrogels.
Conclusion:
In summary, HAMI hydrogels show a great potential as IOL biomaterials that can
maintain the sustained release of indomethacin and filter harmful blue light after cataract surgery.
Lay Summary:
People with cataract surgery can be at high risk of postoperative complications,
such as PCO and postoperative endophthalmitis. Moreover, early IOLs allowed all ultraviolet
(UV) and visible light to pass through retina without restriction, thus to damage the retina and
the retinal pigment epithelium, which may lead to retinopathy and age-related macular degeneration
(AMD). Herein, we sought to design and prepare a kind of IOLs loaded with indomethacin
to mitigate those postoperative complications and filter harmful blue light to improve the
treatment prognosis.
Collapse
Affiliation(s)
- Yang Xiang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
| | - Mengwei Zou
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
| | - Ying Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Rongrong Jin
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
| | - Yu Nie
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
| |
Collapse
|
8
|
Khurana B, Gierlich P, Meindl A, Gomes-da-Silva LC, Senge MO. Hydrogels: soft matters in photomedicine. Photochem Photobiol Sci 2019; 18:2613-2656. [PMID: 31460568 DOI: 10.1039/c9pp00221a] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Photodynamic therapy (PDT), a shining beacon in the realm of photomedicine, is a non-invasive technique that utilizes dye-based photosensitizers (PSs) in conjunction with light and oxygen to produce reactive oxygen species to combat malignant tissues and infectious microorganisms. Yet, for PDT to become a common, routine therapy, it is still necessary to overcome limitations such as photosensitizer solubility, long-term side effects (e.g., photosensitivity) and to develop safe, biocompatible and target-specific formulations. Polymer based drug delivery platforms are an effective strategy for the delivery of PSs for PDT applications. Among them, hydrogels and 3D polymer scaffolds with the ability to swell in aqueous media have been deeply investigated. Particularly, hydrogel-based formulations present real potential to fulfill all requirements of an ideal PDT platform by overcoming the solubility issues, while improving the selectivity and targeting drawbacks of the PSs alone. In this perspective, we summarize the use of hydrogels as carrier systems of PSs to enhance the effectiveness of PDT against infections and cancer. Their potential in environmental and biomedical applications, such as tissue engineering photoremediation and photochemistry, is also discussed.
Collapse
Affiliation(s)
- Bhavya Khurana
- Medicinal Chemistry, Trinity Translational Medicine Institute, Trinity Centre for Health Sciences, Trinity College Dublin, The University of Dublin, St James's Hospital, Dublin 8, Ireland.
| | - Piotr Gierlich
- Medicinal Chemistry, Trinity Translational Medicine Institute, Trinity Centre for Health Sciences, Trinity College Dublin, The University of Dublin, St James's Hospital, Dublin 8, Ireland. and CQC, Coimbra Chemistry Department, University of Coimbra, Coimbra, Portugal
| | - Alina Meindl
- Physik Department E20, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | | | - Mathias O Senge
- Medicinal Chemistry, Trinity Translational Medicine Institute, Trinity Centre for Health Sciences, Trinity College Dublin, The University of Dublin, St James's Hospital, Dublin 8, Ireland. and Physik Department E20, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany and Institute for Advanced Study (TUM-IAS), Technische Universität München, Lichtenberg-Str. 2a, 85748 Garching, Germany
| |
Collapse
|
9
|
Q Mesquita M, J Dias C, P M S Neves MG, Almeida A, F Faustino MA. Revisiting Current Photoactive Materials for Antimicrobial Photodynamic Therapy. Molecules 2018; 23:E2424. [PMID: 30248888 PMCID: PMC6222430 DOI: 10.3390/molecules23102424] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 12/22/2022] Open
Abstract
Microbial infection is a severe concern, requiring the use of significant amounts of antimicrobials/biocides, not only in the hospital setting, but also in other environments. The increasing use of antimicrobial drugs and the rapid adaptability of microorganisms to these agents, have contributed to a sharp increase of antimicrobial resistance. It is obvious that the development of new strategies to combat planktonic and biofilm-embedded microorganisms is required. Photodynamic inactivation (PDI) is being recognized as an effective method to inactivate a broad spectrum of microorganisms, including those resistant to conventional antimicrobials. In the last few years, the development and biological assessment of new photosensitizers for PDI were accompanied by their immobilization in different supports having in mind the extension of the photodynamic principle to new applications, such as the disinfection of blood, water, and surfaces. In this review, we intended to cover a significant amount of recent work considering a diversity of photosensitizers and supports to achieve an effective photoinactivation. Special attention is devoted to the chemistry behind the preparation of the photomaterials by recurring to extensive examples, illustrating the design strategies. Additionally, we highlighted the biological challenges of each formulation expecting that the compiled information could motivate the development of other effective photoactive materials.
Collapse
Affiliation(s)
- Mariana Q Mesquita
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
- Department of Biomedical Sciences and iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Cristina J Dias
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Maria G P M S Neves
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Adelaide Almeida
- Department of Biology CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - M Amparo F Faustino
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
| |
Collapse
|
10
|
Wang W, Lu D, Zhu M, Saunders JM, Milani AH, Armes SP, Saunders BR. Highly deformable hydrogels constructed by pH-triggered polyacid nanoparticle disassembly in aqueous dispersions. SOFT MATTER 2018; 14:3510-3520. [PMID: 29671461 DOI: 10.1039/c8sm00325d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Most hydrogels are prepared using small-molecule monomers but unfortunately this approach may not be feasible for certain biomaterial applications. Consequently, alternative gel construction strategies have been established, which include using covalent inter-linking of preformed gel particles, or microgels (MGs). For example, covalently interlinking pH-responsive MGs can produce hydrogels comprising doubly crosslinked microgels (DX MGs). We hypothesised that the deformability of such DX MGs was limited by the presence of intra-MG crosslinking. Thus, in this study we designed new nanoparticle (NP)-based gels based on pH-swellable NPs that are not internally crosslinked. Two polyacid NPs were synthesised containing methacrylic acid (MAA) and either ethyl acrylate (EA) or methyl methacrylate (MMA). The PMAA-EA and PMAA-MMA NPs were subsequently vinyl-functionalised using glycidyl methacrylate (GMA) prior to gel formation via free-radical crosslinking. The NPs mostly disassembled on raising the solution pH but some self-crosslinking was nevertheless evident. The gels constructed from the EA- and MMA-based NPs had greater breaking strains than a control DX MG. The effect of varying the solution pH during curing on the morphology and mechanical properties of gels prepared using PMAA-MMA-GMA NPs was studied and both remarkable deformability and excellent recovery were observed. The gels were strongly pH-responsive and had tensile breaking strains of up to 420% with a compressive strain-at-break of more than 93%. An optimised formulation produced the most deformable and stretchable gel yet constructed using NPs or MGs as the only building block.
Collapse
Affiliation(s)
- Wenkai Wang
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Dongdong Lu
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Mingning Zhu
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Jennifer M Saunders
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Amir H Milani
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| | - Steven P Armes
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK
| | - Brian R Saunders
- School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.
| |
Collapse
|
11
|
Li Y, Pi QM, You HH, Li JQ, Wang PC, Yang X, Wu Y. A smart multi-functional coating based on anti-pathogen micelles tethered with copper nanoparticlesviaa biosynthesis method usingl-vitamin C. RSC Adv 2018; 8:18272-18283. [PMID: 35541145 PMCID: PMC9080516 DOI: 10.1039/c8ra01985a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/13/2018] [Indexed: 01/29/2023] Open
Abstract
A multi-functional anti-pathogen coating with “release-killing”, “contact-killing” and “anti-adhesion” properties was prepared from biocompatible polymer encapsulated chlorine dioxide (ClO2) which protected the active ingredient from the outside environment.
Collapse
Affiliation(s)
- Yan Li
- Key Laboratory for Deep Processing of Major Grain and Oil (Wuhan Polytechnic University)
- Ministry of Education
- College of Food Science and Engineering
- Wuhan Polytechnic University
- Wuhan 430023
| | - Qing-meng Pi
- Department of Plastic and Reconstructive Surgery
- Renji Hospital
- Shanghai Jiaotong University School of Medicine
- Shanghai 200129
- P. R. China
| | - Hui-hui You
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology
- College of Life Sciences
- Central China Normal University
- Wuhan 430079
- P. R. China
| | - Jin-quan Li
- Brain and Cognitive Dysfunction Research Center
- School of Medicine
- Wuhan University of Science and Technology
- Wuhan 430081
- P. R. China
| | - Peng-cheng Wang
- Key Laboratory for Deep Processing of Major Grain and Oil (Wuhan Polytechnic University)
- Ministry of Education
- College of Food Science and Engineering
- Wuhan Polytechnic University
- Wuhan 430023
| | - Xu Yang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology
- College of Life Sciences
- Central China Normal University
- Wuhan 430079
- P. R. China
| | - Yang Wu
- Key Laboratory for Deep Processing of Major Grain and Oil (Wuhan Polytechnic University)
- Ministry of Education
- College of Food Science and Engineering
- Wuhan Polytechnic University
- Wuhan 430023
| |
Collapse
|
12
|
Li X, Zhao Y, Wang K, Wang L, Yang X, Zhu S. Cyclodextrin-containing hydrogels as an intraocular lens for sustained drug release. PLoS One 2017; 12:e0189778. [PMID: 29244868 PMCID: PMC5731761 DOI: 10.1371/journal.pone.0189778] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 11/12/2017] [Indexed: 12/30/2022] Open
Abstract
To improve the efficacy of anti-inflammatory factors in patients who undergo cataract surgery, poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) hydrogels containing β-cyclodextrin (β-CD) (pHEMA/MMA/β-CD) were designed and prepared as intraocular lens (IOLs) biomaterials that could be loaded with and achieve the sustained release of dexamethasone. A series of pHEMA/MMA/β-CD copolymers containing different ratios of β-CD (range, 2.77 to 10.24 wt.%) were obtained using thermal polymerization. The polymers had high transmittance at visible wavelengths and good biocompatibility with mouse connective tissue fibroblasts. Drug loading and release studies demonstrated that introducing β-CD into hydrogels increased loading efficiency and achieved the sustained release of the drug. Administering β-CD via hydrogels increased the equilibrium swelling ratio, elastic modulus and tensile strength. In addition, β-CD increased the hydrophilicity of the hydrogels, resulting in a lower water contact angle and higher cellular adhesion to the hydrogels. In summary, pHEMA/MMA/β-CD hydrogels show great potential as IOL biomaterials that are capable of maintaining the sustained release of anti-inflammatory drugs after cataract surgery.
Collapse
Affiliation(s)
- Xiao Li
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Zhao
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kaijie Wang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Lei Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST), Beijing, China
- * E-mail: (LW); (XY); (SZ)
| | - Xiaohui Yang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- * E-mail: (LW); (XY); (SZ)
| | - Siquan Zhu
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- * E-mail: (LW); (XY); (SZ)
| |
Collapse
|
13
|
Tan JPK, Coady DJ, Sardon H, Yuen A, Gao S, Lim SW, Liang ZC, Tan EW, Venkataraman S, Engler AC, Fevre M, Ono R, Yang YY, Hedrick JL. Broad Spectrum Macromolecular Antimicrobials with Biofilm Disruption Capability and In Vivo Efficacy. Adv Healthc Mater 2017; 6. [PMID: 28504348 DOI: 10.1002/adhm.201601420] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/24/2017] [Indexed: 12/28/2022]
Abstract
In this study, antimicrobial polymers are synthesized by the organocatalytic ring-opening polymerization of an eight-membered heterocyclic carbonate monomer that is subsequently quaternized with methyl iodide. These polymers demonstrate activity against clinically relevant Gram-positive Staphylococcus epidermidis and Staphylococcus aureus, Gram-negative Escherichia coli and Pseudomonas aeruginosa, and fungus Candida albicans with fast killing kinetics. Importantly, the polymer efficiently inhibits biofilm growth and lyses existing biofilm, leading to a reduction in biomass and cell viability. In addition, the macromolecular antimicrobial is less likely to induce resistance as it acts via a membrane-lytic mechanism. The polymer is not cytotoxic toward mammalian cells with LD50 of 99.0 ± 11.6 mg kg-1 in mice through i.v. injection. In an S. aureus blood stream infection mouse model, the polymer removes bacteria from the blood more rapidly than the antibiotic Augmentin. At the effective dose, the polymer treatment does not damage liver and kidney tissues or functions. In addition, blood electrolyte balance remains unchanged after the treatment. The low cost of starting materials, ease of synthesis, nontoxicity, broad spectrum activity with fast killing kinetics, and in vivo antimicrobial activity make these macromolecular antimicrobials ideal candidates for prevention of sepsis and treatment of infections.
Collapse
Affiliation(s)
- Jeremy P. K. Tan
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Daniel J. Coady
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| | - Haritz Sardon
- POLYMAT; University of the Basque Country UPV/EHU Joxe Mari Korta Center; Avda. Tolosa 72 20018 Donostia-San Sebastián Spain
- Ikerbasque, Basque Foundation for Science; E-48011 Bilbao Spain
| | - Alexander Yuen
- POLYMAT; University of the Basque Country UPV/EHU Joxe Mari Korta Center; Avda. Tolosa 72 20018 Donostia-San Sebastián Spain
| | - Shujun Gao
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Shaun W. Lim
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Zhen Chang Liang
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Eddy W. Tan
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Shrinivas Venkataraman
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - Amanda C. Engler
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| | - Mareva Fevre
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| | - Robert Ono
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| | - Yi Yan Yang
- Institute of Bioengineering and Nanotechnology; 31 Biopolis Way Singapore 138669 Singapore
| | - James L. Hedrick
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| |
Collapse
|
14
|
Castriciano MA, Zagami R, Casaletto MP, Martel B, Trapani M, Romeo A, Villari V, Sciortino MT, Grasso L, Guglielmino S, Scolaro LM, Mazzaglia A. Poly(carboxylic acid)-Cyclodextrin/Anionic Porphyrin Finished Fabrics as Photosensitizer Releasers for Antimicrobial Photodynamic Therapy. Biomacromolecules 2017; 18:1134-1144. [PMID: 28257182 DOI: 10.1021/acs.biomac.6b01752] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the development of new antibacterial therapeutic approaches to fight multidrug-resistant bacteria, antimicrobial photodynamic therapy (aPDT) represents a well-known alternative to treat local infections caused by different microorganisms. Here we present a polypropylene (PP) fabric finished with citrate-hydroxypropyl-βCD polymer (PP-CD) entrapping the tetra-anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphine (TPPS) as photosensitizer-eluting scaffold (PP-CD/TPPS) for aPDT. The concept is based on host-guest complexation of porphyrin in the cavities of CDs immobilized on the PP fibers, followed by its sustained and controlled delivery in release medium and simultaneous photoinactivation of microorganisms. Morphology of fabric was characterized by optical (OM) and scanning electron microscopies (SEM). Optical properties were investigated by UV-vis absorption, steady- and time-resolved fluorescence emission spectroscopy. X-ray photoelectron spectroscopy (XPS) and FT-IR revealed the surface chemical composition and the distribution map of the molecular components on the fabric, respectively. Direct 1O2 determination allowed to assess the potential photodynamic activity of the fabric. Release kinetics of TPPS in physiological conditions pointed out the role of the CD cavity to control the TPPS elution. Photoantimicrobial activity of the porphyrin-loaded textile was investigated against both Gram-positive Staphylococcus aureus ATCC 29213 (S. aureus) and Gram-negative Pseudomonas aeruginosa ATCC 27853 (P. aeruginosa). Optical microscopy coupled with UV-vis extinction and fluorescence spectra aim to ascertain the uptake of TPPS to S. aureus bacterial cells. Finally, PP-CD/TPPS fabric-treated S. aureus cells were photokilled of 99.98%. Moreover, low adhesion of S. aureus cells on textile was established. Conversely, no photodamage of fabric-treated P. aeruginosa cells was observed, together with their satisfying adhesion.
Collapse
Affiliation(s)
- Maria Angela Castriciano
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy
| | - Roberto Zagami
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy
| | - Maria Pia Casaletto
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati , Via Ugo La Malfa, 153, 90146, Palermo, Italy
| | - Bernard Martel
- Unité Matériaux et Transformations, UMET CNRS 8207, University of Science and Technology of Lille , 59655, Villeneuve d'Ascq, France
| | - Mariachiara Trapani
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy
| | - Andrea Romeo
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy.,Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , Viale F. Stagno d'Alcontres, 31, 98166, Messina, Italy.,C.I.R.C.M.S.B, Unity of Messina , Messina, Italy
| | - Valentina Villari
- Consiglio Nazionale delle Ricerche, Istituto per i processi Chimico-Fisici , Viale F. Stagno d'Alcontres 37, 98158, Messina, Italy
| | - Maria Teresa Sciortino
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , Viale F. Stagno d'Alcontres, 31, 98166, Messina, Italy
| | - Laura Grasso
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , Viale F. Stagno d'Alcontres, 31, 98166, Messina, Italy
| | - Salvatore Guglielmino
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , Viale F. Stagno d'Alcontres, 31, 98166, Messina, Italy
| | - Luigi Monsù Scolaro
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy.,Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , Viale F. Stagno d'Alcontres, 31, 98166, Messina, Italy.,C.I.R.C.M.S.B, Unity of Messina , Messina, Italy
| | - Antonino Mazzaglia
- Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina , V.le F. Stagno D'Alcontres, 31, 98166, Messina, Italy
| |
Collapse
|
15
|
Production and characterisation of acrylate-based microparticles for photosensitizer incorporation to their surfaces. Photodiagnosis Photodyn Ther 2017. [DOI: 10.1016/j.pdpdt.2017.01.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
16
|
Hydrophilic modification of intraocular lens via surface initiated reversible addition-fragmentation chain transfer polymerization for reduced posterior capsular opacification. Colloids Surf B Biointerfaces 2017; 151:271-279. [DOI: 10.1016/j.colsurfb.2016.12.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/15/2016] [Accepted: 12/19/2016] [Indexed: 01/05/2023]
|
17
|
Abstract
Objective: This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs). Data Sources: All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect. Study Selection: The articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded. Results: Technology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol), polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO2, heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments. Conclusion: The surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs.
Collapse
Affiliation(s)
| | | | | | - Gui-Qin Wang
- Department of Ophthalmology, Navy General Hospital of PLA, Beijing 100048; Department of Ophthalmilogy, Third Clinical Medical College of Southern Medical University, Guangzhou, Guangdong 510515, China
| |
Collapse
|
18
|
Han Y, Xu X, Tang J, Shen C, Lin Q, Chen H. Bottom-up fabrication of zwitterionic polymer brushes on intraocular lens for improved biocompatibility. Int J Nanomedicine 2016; 12:127-135. [PMID: 28053528 PMCID: PMC5191625 DOI: 10.2147/ijn.s107491] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Intraocular lens (IOL) is an efficient implantable device commonly used for treating cataracts. However, bioadhesion of bacteria or residual lens epithelial cells on the IOL surface after surgery causes postoperative complications, such as endophthalmitis or posterior capsular opacification, and leads to loss of sight again. In the present study, zwitterionic polymer brushes were fabricated on the IOL surface via bottom-up grafting procedure. The attenuated total reflection-Fourier transform infrared and contact angle measurements indicated successful surface modification, as well as excellent hydrophilicity. The coating of hydrophilic zwitterionic polymer effectively decreased the bioadhesion of lens epithelial cells or bacteria. In vivo intraocular implantation results showed good in vivo biocompatibility of zwitterionic IOL and its effectiveness against postoperative complications.
Collapse
Affiliation(s)
- Yuemei Han
- School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University
| | - Xu Xu
- School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University
| | - Junmei Tang
- School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University
| | - Chenghui Shen
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Quankui Lin
- School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Hao Chen
- School of Ophthalmology & Optometry, Eye Hospital, Wenzhou Medical University
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| |
Collapse
|
19
|
Wang B, Ye Z, Tang Y, Han Y, Lin Q, Liu H, Chen H, Nan K. Fabrication of nonfouling, bactericidal, and bacteria corpse release multifunctional surface through surface-initiated RAFT polymerization. Int J Nanomedicine 2016; 12:111-125. [PMID: 28053527 PMCID: PMC5191580 DOI: 10.2147/ijn.s107472] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Infections after surgery or endophthalmitis are potentially blinding complications caused by bacterial adhesion and subsequent biofilm formation on the intraocular lens. Neither single-function anti-adhesion surface nor contacting killing surface can exhibit ideal antibacterial function. In this work, a novel (2-(dimethylamino)-ethyl methacrylate-co-2-methacryloyloxyethyl phosphorylcholine) (p (DMAEMA-co-MPC)) brush was synthesized by "grafting from" method through reversible-addition fragmentation chain transfer polymerization. 1-Bromoheptane was used to quaternize the p (DMAEMA-co-MPC) brush coating and to endow the surface with bactericidal function. The success of the surface functionalization was confirmed by atomic force microscopy, water contact angle, and spectroscopic ellipsometry. The quaternary ammonium salt units were employed as efficient disinfection that can eliminate bacteria through contact killing, whereas the 2-methacryloyloxyethyl phosphorylcholine units were introduced to suppress unwanted nonspecific adsorption. The functionalized poly(dimethyl siloxane) surfaces showed efficiency in reducing bovine serum albumin adsorption and in inhibiting bacteria adhesion and biofilm formation. The copolymer brushes also demonstrated excellent bactericidal function against gram-positive (Staphylococcus aureus) bacteria measured by bacteria live/dead staining and shake-flask culture methods. The surface biocompatibility was evaluated by morphology and activity measurement with human lens epithelial cells in vitro. The achievement of the p (DMAEMA+-co-MPC) copolymer brush coating with nonfouling, bactericidal, and bacteria corpse release properties can be used to modify intraocular lenses.
Collapse
Affiliation(s)
- Bailiang Wang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Zi Ye
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
| | - Yihong Tang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
| | - Yuemei Han
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
| | - Quankui Lin
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Huihua Liu
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Hao Chen
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| | - Kaihui Nan
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences, Wenzhou, People’s Republic of China
| |
Collapse
|
20
|
The impact of surface chemistry modification on macrophage polarisation. Immunobiology 2016; 221:1237-46. [DOI: 10.1016/j.imbio.2016.06.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/01/2016] [Accepted: 06/10/2016] [Indexed: 12/22/2022]
|
21
|
Jiang L, Gan CRR, Gao J, Loh XJ. A Perspective on the Trends and Challenges Facing Porphyrin-Based Anti-Microbial Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:3609-3644. [PMID: 27276371 DOI: 10.1002/smll.201600327] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 05/05/2016] [Indexed: 06/06/2023]
Abstract
The emergence of multidrug resistant bacterium threatens to unravel global healthcare systems, built up over centuries of medical research and development. Current antibiotics have little resistance against this onslaught as bacterium strains can quickly evolve effective defense mechanisms. Fortunately, alternative therapies exist and, at the forefront of research lays the photodynamic inhibition approach mediated by porphyrin based photosensitizers. This review will focus on the development of various porphyrins compounds and their incorporation as small molecules, into polymers, fibers and thin films as practical therapeutic agents, utilizing photodynamic therapy to inhibit a wide spectrum of bacterium. The use of photodynamic therapy of these porphyrin molecules are discussed and evaluated according to their electronic and bulk material effect on different bacterium strains. This review also provides an insight into the general direction and challenges facing porphyrins and derivatives as full-fledged therapeutic agents and what needs to be further done in order to be bestowed their rightful and equal status in modern medicine, similar to the very first antibiotic; penicillin itself. It is hoped that, with this perspective, new paradigms and strategies in the application of porphyrins and derivatives will progressively flourish and lead to advances against disease.
Collapse
Affiliation(s)
- Lu Jiang
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore, 138634, Republic of Singapore
| | - Ching Ruey Raymond Gan
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore, 138634, Republic of Singapore
| | - Jian Gao
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore, 138634, Republic of Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore, 138634, Republic of Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Republic of Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Republic of Singapore
| |
Collapse
|
22
|
Lin QK, Xu X, Wang Y, Wang B, Chen H. Antiadhesive and antibacterial polysaccharide multilayer as IOL coating for prevention of postoperative infectious endophthalmitis. INT J POLYM MATER PO 2016. [DOI: 10.1080/00914037.2016.1190925] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
23
|
Litman Y, Rodríguez HB, San Román E. Tuning the concentration of dye loaded polymer films for maximum photosensitization efficiency: phloxine B in poly(2-hydroxyethyl methacrylate). Photochem Photobiol Sci 2016; 15:80-5. [DOI: 10.1039/c5pp00360a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Excitation of a dye confined in a polymeric matrix leads to energy trapping at high concentrations.
Collapse
Affiliation(s)
- Yair Litman
- INQUIMAE (UBA-CONICET)/DQIAyQF
- Facultad de Ciencias Exactas y Naturales
- Universidad de Buenos Aires
- Buenos Aires
- Argentina
| | - Hernán B. Rodríguez
- INQUIMAE (UBA-CONICET)/DQIAyQF
- Facultad de Ciencias Exactas y Naturales
- Universidad de Buenos Aires
- Buenos Aires
- Argentina
| | - Enrique San Román
- INQUIMAE (UBA-CONICET)/DQIAyQF
- Facultad de Ciencias Exactas y Naturales
- Universidad de Buenos Aires
- Buenos Aires
- Argentina
| |
Collapse
|
24
|
De Baróid ÁT, McCoy CP, Craig RA, Carson L, Andrews GP, Jones DS, Gorman SP. Optimization of singlet oxygen production from photosensitizer-incorporated, medically relevant hydrogels. J Biomed Mater Res B Appl Biomater 2015; 105:320-326. [PMID: 26505264 PMCID: PMC5244673 DOI: 10.1002/jbm.b.33562] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/05/2015] [Accepted: 10/11/2015] [Indexed: 11/12/2022]
Abstract
Photodynamic therapy and photodynamic antimicrobial chemotherapy are widely used, but despite this, the relationships between fluence, wavelength of irradiation and singlet oxygen (1O2) production are poorly understood. To establish the relationships between these factors in medically relevant materials, the effect of fluence on 1O2 production from a tetrakis(4‐N‐methylpyridyl)porphyrin (TMPyP)‐incorporated 2‐hydroxyethyl methacrylate: methyl methacrylate: methacrylic acid (HEMA: MMA:MAA) copolymer, a total energy of 50.48 J/cm2, was applied at varying illumination power, and times. 1O2 production was characterized using anthracene‐9,10‐dipropionic acid, disodium salt (ADPA) using a recently described method. Using two light sources, a white LED array and a white halogen source, the LED array was found to produce less 1O2 than the halogen source when the same power (over 500 − 600 nm) and time conditions were applied. Importantly, it showed that the longest wavelength Q band (590 nm) is primarily responsible for 1O2 generation, and that a linear relationship exists between increasing power and time and the production of singlet oxygen. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 320–326, 2017.
Collapse
Affiliation(s)
- Áine T De Baróid
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Colin P McCoy
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Rebecca A Craig
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Louise Carson
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Gavin P Andrews
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - David S Jones
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Sean P Gorman
- School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, UK
| |
Collapse
|
25
|
|
26
|
Cavaleiro E, Duarte AS, Esteves AC, Correia A, Whitcombe MJ, Piletska EV, Piletsky SA, Chianella I. Novel linear polymers able to inhibit bacterial quorum sensing. Macromol Biosci 2015; 15:647-56. [PMID: 25626858 DOI: 10.1002/mabi.201400447] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/05/2014] [Indexed: 11/11/2022]
Abstract
Bacterial phenotypes, such as biofilm formation, antibiotic resistance and virulence expression, are associated with quorum sensing. Quorum sensing is a density-dependent regulatory system of gene expression controlled by specific signal molecules, such as N-acyl homoserine lactones (AHLs), produced and released by bacteria. This study reports the development of linear polymers capable to attenuate quorum sensing by adsorption of AHLs. Linear polymers were synthesized using MMA as backbone monomer and methacrylic acid and itaconic acid as functional monomers. Two different quorum sensing-controlled phenotypes, Vibrio fischeri bioluminescence and Aeromonas hydrophila biofilm formation, were evaluated to test the polymers' efficiency. Results showed that both phenotypes were significantly affected by the polymers, with the itaconic acid-containing material being more effective than the methacrylic acid one. The polymer inhibitory effects were reverted by the addition of lactones, confirming attenuation of quorum sensing through sequestration of signal molecules. The polymers also showed no cytotoxicity when tested using a mammalian cell line.
Collapse
Affiliation(s)
- Eliana Cavaleiro
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.,Centre for Biomedical Engineering, SATM, Cranfield University, Cranfield, Beds, UK
| | - Ana Sofia Duarte
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.
| | | | - António Correia
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | | | | | | | - Iva Chianella
- Centre for Biomedical Engineering, SATM, Cranfield University, Cranfield, Beds, UK
| |
Collapse
|
27
|
Rostam HM, Singh S, Vrana NE, Alexander MR, Ghaemmaghami AM. Impact of surface chemistry and topography on the function of antigen presenting cells. Biomater Sci 2015. [DOI: 10.1039/c4bm00375f] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The impact of biomaterial surface topography and chemistry on antigen presenting cells’ phenotype and function.
Collapse
Affiliation(s)
- H. M. Rostam
- Immunology and Tissue Modelling Group
- School of Life Science
- University of Nottingham
- Queen's Medical Centre
- Nottingham
| | - S. Singh
- Immunology and Tissue Modelling Group
- School of Life Science
- University of Nottingham
- Queen's Medical Centre
- Nottingham
| | - N. E. Vrana
- Université de Strasbourg
- Faculté de Chirurgie Dentaire
- France
- Protip SAS
- Strasbourg
| | - M. R. Alexander
- Interface and Surface Analysis Centre
- School of Pharmacy
- University of Nottingham
- UK
| | - A. M. Ghaemmaghami
- Immunology and Tissue Modelling Group
- School of Life Science
- University of Nottingham
- Queen's Medical Centre
- Nottingham
| |
Collapse
|
28
|
Lin Q, Xu X, Wang B, Shen C, Tang J, Han Y, Chen H. Hydrated polysaccharide multilayer as an intraocular lens surface coating for biocompatibility improvements. J Mater Chem B 2015; 3:3695-3703. [PMID: 32262844 DOI: 10.1039/c5tb00111k] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A swollen polysaccharide multilayer was coated on an IOL to inhibit LEC adhesion and proliferation, thus decreasing PCO incidence after implantation.
Collapse
Affiliation(s)
- Quankui Lin
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| | - Xu Xu
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| | - Bailiang Wang
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| | - Chenghui Shen
- Wenzhou Institute of Biomaterials and Engineering
- Wenzhou
- China
| | - Junmei Tang
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| | - Yuemei Han
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| | - Hao Chen
- School of Ophthalmology & Optometry
- Eye Hospital
- Wenzhou Medical University
- Wenzhou 325027
- China
| |
Collapse
|
29
|
McCloskey AP, Gilmore BF, Laverty G. Evolution of antimicrobial peptides to self-assembled peptides for biomaterial applications. Pathogens 2014; 3:791-821. [PMID: 25436505 PMCID: PMC4282886 DOI: 10.3390/pathogens3040791] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/17/2014] [Accepted: 09/25/2014] [Indexed: 11/17/2022] Open
Abstract
Biomaterial-related infections are a persistent burden on patient health, recovery, mortality and healthcare budgets. Self-assembled antimicrobial peptides have evolved from the area of antimicrobial peptides. Peptides serve as important weapons in nature, and increasingly medicine, for combating microbial infection and biofilms. Self-assembled peptides harness a "bottom-up" approach, whereby the primary peptide sequence may be modified with natural and unnatural amino acids to produce an inherently antimicrobial hydrogel. Gelation may be tailored to occur in the presence of physiological and infective indicators (e.g. pH, enzymes) and therefore allow local, targeted antimicrobial therapy at the site of infection. Peptides demonstrate inherent biocompatibility, antimicrobial activity, biodegradability and numerous functional groups. They are therefore prime candidates for the production of polymeric molecules that have the potential to be conjugated to biomaterials with precision. Non-native chemistries and functional groups are easily incorporated into the peptide backbone allowing peptide hydrogels to be tailored to specific functional requirements. This article reviews an area of increasing interest, namely self-assembled peptides and their potential therapeutic applications as innovative hydrogels and biomaterials in the prevention of biofilm-related infection.
Collapse
Affiliation(s)
- Alice P McCloskey
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland.
| | - Brendan F Gilmore
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland.
| | - Garry Laverty
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland.
| |
Collapse
|
30
|
McCoy CP, O’Neil EJ, Cowley JF, Carson L, De Baróid ÁT, Gdowski GT, Gorman SP, Jones DS. Photodynamic antimicrobial polymers for infection control. PLoS One 2014; 9:e108500. [PMID: 25250740 PMCID: PMC4177408 DOI: 10.1371/journal.pone.0108500] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/29/2014] [Indexed: 12/04/2022] Open
Abstract
Hospital-acquired infections pose both a major risk to patient wellbeing and an economic burden on global healthcare systems, with the problem compounded by the emergence of multidrug resistant and biocide tolerant bacterial pathogens. Many inanimate surfaces can act as a reservoir for infection, and adequate disinfection is difficult to achieve and requires direct intervention. In this study we demonstrate the preparation and performance of materials with inherent photodynamic, surface-active, persistent antimicrobial properties through the incorporation of photosensitizers into high density poly(ethylene) (HDPE) using hot-melt extrusion, which require no external intervention except a source of visible light. Our aim is to prevent bacterial adherence to these surfaces and eliminate them as reservoirs of nosocomial pathogens, thus presenting a valuable advance in infection control. A two-layer system with one layer comprising photosensitizer-incorporated HDPE, and one layer comprising HDPE alone is also described to demonstrate the versatility of our approach. The photosensitizer-incorporated materials are capable of reducing the adherence of viable bacteria by up to 3.62 Log colony forming units (CFU) per square centimeter of material surface for methicillin resistant Staphylococcus aureus (MRSA), and by up to 1.51 Log CFU/cm2 for Escherichia coli. Potential applications for the technology are in antimicrobial coatings for, or materials comprising objects, such as tubing, collection bags, handrails, finger-plates on hospital doors, or medical equipment found in the healthcare setting.
Collapse
Affiliation(s)
- Colin P. McCoy
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
- * E-mail:
| | - Edward J. O’Neil
- Blue Highway, Inc., Center for Science & Technology, Syracuse University, Syracuse, New York, United States of America
| | - John F. Cowley
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| | - Louise Carson
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| | - Áine T. De Baróid
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| | - Greg T. Gdowski
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| | - Sean P. Gorman
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| | - David S. Jones
- Queen’s University Belfast, School of Pharmacy, Belfast, United Kingdom
| |
Collapse
|
31
|
Craig RA, McCoy CP, Gorman SP, Jones DS. Photosensitisers - the progression from photodynamic therapy to anti-infective surfaces. Expert Opin Drug Deliv 2014; 12:85-101. [PMID: 25247277 DOI: 10.1517/17425247.2015.962512] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The application of light as a stimulus in pharmaceutical systems and the associated ability to provide precise spatiotemporal control over location, wavelength and intensity, allowing ease of external control independent of environmental conditionals, has led to its increased use. Of particular note is the use of light with photosensitisers. AREAS COVERED Photosensitisers are widely used in photodynamic therapy to cause a cidal effect towards cells on irradiation due to the generation of reactive oxygen species. These cidal effects have also been used to treat infectious diseases. The effects and benefits of photosensitisers in the treatment of such conditions are still being developed and further realised, with the design of novel delivery strategies. This review provides an overview of the realisation of the pharmaceutically relevant uses of photosensitisers, both in the context of current research and in terms of current clinical application, and looks to the future direction of research. EXPERT OPINION Substantial advances have been and are being made in the use of photosensitisers. Of particular note are their antimicrobial applications, due to absence of resistance that is so frequently associated with conventional treatments. Their potency of action and the ability to immobilise to polymeric supports is opening a wide range of possibilities with great potential for use in healthcare infection prevention strategies.
Collapse
Affiliation(s)
- Rebecca A Craig
- Queen's University Belfast, School of Pharmacy , 97 Lisburn Road, Belfast, BT9 7BL , UK
| | | | | | | |
Collapse
|
32
|
Kara F, Aksoy EA, Yuksekdag Z, Hasirci N, Aksoy S. Synthesis and surface modification of polyurethanes with chitosan for antibacterial properties. Carbohydr Polym 2014; 112:39-47. [PMID: 25129714 DOI: 10.1016/j.carbpol.2014.05.019] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/14/2014] [Accepted: 05/15/2014] [Indexed: 01/26/2023]
Abstract
Surface modification and providing antibacterial properties to the materials or devices are getting great attention especially in the last decades. In this study, polyurethane (PU) films were prepared by synthesizing them in medical purity from toluene diisocyanate and polypropylene ethylene glycol without using any other ingredients and then the film surfaces were modified by covalent immobilization of chitosan (CH) which has antibacterial activity. CH immobilized PU films (PU-CH) were found to be more hydrophilic than control PU films. Electron Spectroscopy for Chemical Analysis (ESCA) and Atomic Force Microscopy (AFM) analyses showed higher nitrogen contents and rougher surface topography for PU-CH compared to PU films. Modification with CH significantly increased antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) bacteria. It was observed that the number of bacteria colonies were less about 10(2)-10(5) CFU/mL and number of attached viable bacteria decreased significantly after CH modification of PU films.
Collapse
Affiliation(s)
- Filiz Kara
- Department of Chemistry, Faculty of Science, Gazi University, 06500 Ankara, Turkey
| | - Eda Ayse Aksoy
- Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey; BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University, Dumlupınar Bulvarı, No:1, 06800 Cankaya, Ankara, Turkey
| | - Zehranur Yuksekdag
- Department of Biology, Biotechnology Laboratory, Faculty of Science, Gazi University, 06500 Ankara, Turkey
| | - Nesrin Hasirci
- BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University, Dumlupınar Bulvarı, No:1, 06800 Cankaya, Ankara, Turkey; Department of Chemistry, Faculty of Arts and Sciences, Middle East Technical University, 06800 Ankara, Turkey
| | - Serpil Aksoy
- Department of Chemistry, Faculty of Science, Gazi University, 06500 Ankara, Turkey.
| |
Collapse
|