1
|
Wong K, Liu Y, Wong M, Liu J. Cornea-SELEX for aptamers targeting the surface of eyes and liposomal drug delivery. EXPLORATION (BEIJING, CHINA) 2024; 4:20230008. [PMID: 39175889 PMCID: PMC11335462 DOI: 10.1002/exp.20230008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 01/07/2024] [Indexed: 08/24/2024]
Abstract
Cornea is the major barrier to drug delivery to the eye, which results in low bioavailability and poor efficacy of topical eye treatment. In this work, we first select cornea-binding aptamers using tissue-SELEX on pig cornea. The top two abundant aptamers, Cornea-S1 and Cornea-S2, could bind to pig cornea, and their K d values to human corneal epithelial cells (HCECs) were 361 and 174 nм, respectively. Aptamer-functionalized liposomes loaded with cyclosporine A (CsA) were developed as a treatment for dry eye diseases. The K d of Cornea-S1- or Cornea-S2-functionalized liposomes reduces to 1.2 and 15.1 nм, respectively, due to polyvalent binding. In HCECs, Cornea-S1 or Cornea-S2 enhanced liposome uptake within 15 min and extended retention to 24 h. Aptamer CsA liposomes achieved similar anti-inflammatory and tight junction modulation effects with ten times less CsA than a free drug. In a rabbit dry eye disease model, Cornea-S1 CsA liposomes demonstrated equivalence in sustaining corneal integrity and tear break-up time when compared to commercial CsA eye drops while utilizing a lower dosage of CsA. The aptamers obtained from cornea-SELEX can serve as a general ligand for ocular drug delivery, suggesting a promising avenue for the treatment of various eye diseases and even other diseases.
Collapse
Affiliation(s)
- Ka‐Ying Wong
- Department of Chemistry, Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooOntarioCanada
- Centre for Eye and Vision Research (CEVR)17 W Hong Kong Science ParkHong KongHong Kong
| | - Yibo Liu
- Department of Chemistry, Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooOntarioCanada
- Centre for Eye and Vision Research (CEVR)17 W Hong Kong Science ParkHong KongHong Kong
| | - Man‐Sau Wong
- Centre for Eye and Vision Research (CEVR)17 W Hong Kong Science ParkHong KongHong Kong
- Department of Food Science and NutritionThe Hong Kong Polytechnic UniversityHung Hom, KowloonHong Kong
- Research Center for Chinese Medicine InnovationThe Hong Kong Polytechnic UniversityHung Hom, KowloonHong Kong SARP. R. China
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooOntarioCanada
- Centre for Eye and Vision Research (CEVR)17 W Hong Kong Science ParkHong KongHong Kong
| |
Collapse
|
2
|
Shen S, Zhang Y. Restoration of corneal epithelial barrier function: A possible target for corneal neovascularization. Ocul Surf 2024; 34:38-49. [PMID: 38901546 DOI: 10.1016/j.jtos.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
Corneal neovascularization (CoNV) is the second leading common cause of vision impairment worldwide and is a blinding pathological alteration brought on by ocular trauma, infection, and other factors. There are some limitations in the treatment of CoNV, hence it's critical to look into novel therapeutic targets. The corneal epithelial barrier, which is the initial barrier of the ocular surface, is an important structure that shields the eye from changes in the internal environment or invasion by the external environment. This study sought to collate evidence on the regulation of corneal epithelial barrier injury on the activation of vascular endothelial cells (VECs), basement membrane (BM) degradation, differentiation, migration, and proliferation of VECs, vascular maturation and stability, and other key processes in CoNV, so as to provide a novel concept for CoNV therapy targeting corneal epithelial barrier repair.
Collapse
Affiliation(s)
- Sitong Shen
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Nanguan District, Changchun, Jilin Province, 130041, China
| | - Yan Zhang
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Nanguan District, Changchun, Jilin Province, 130041, China; Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.
| |
Collapse
|
3
|
Wang C, Lan X, Zhu L, Wang Y, Gao X, Li J, Tian H, Liang Z, Xu W. Construction Strategy of Functionalized Liposomes and Multidimensional Application. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309031. [PMID: 38258399 DOI: 10.1002/smll.202309031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/30/2023] [Indexed: 01/24/2024]
Abstract
Liposomes are widely used in the biological field due to their good biocompatibility and surface modification properties. With the development of biochemistry and material science, many liposome structures and their surface functional components have been modified and optimized one by one, pushing the liposome platform from traditional to functionalized and intelligent, which will better satisfy and expand the needs of scientific research. However, a main limiting factor effecting the efficiency of liposomes is the complicated environmental conditions in the living body. Currently, in order to overcome the above problem, functionalized liposomes have become a very promising strategy. In this paper, binding strategies of liposomes with four main functional elements, namely nucleic acids, antibodies, peptides, and stimuli-responsive motif have been summarized for the first time. In addition, based on the construction characteristics of functionalized liposomes, such as drug-carrying, targeting, long-circulating, and stimulus-responsive properties, a comprehensive overview of their features and respective research progress are presented. Finally, the paper critically presents the limitations of these functionalized liposomes in the current applications and also prospectively suggests the future development directions, aiming to accelerate realization of their industrialization.
Collapse
Affiliation(s)
- Chengyun Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Beijing, 100083, China
- College of Food Science and Technology, Hebei Agricultural University, Baoding, Hebei, 071000, China
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Xinyue Lan
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Yanhui Wang
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Xinru Gao
- College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Beijing, 100083, China
| | - Jie Li
- College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Beijing, 100083, China
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Hongtao Tian
- College of Food Science and Technology, Hebei Agricultural University, Baoding, Hebei, 071000, China
| | - Zhihong Liang
- College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Beijing, 100083, China
| | - Wentao Xu
- College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Beijing, 100083, China
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| |
Collapse
|
4
|
Gatto MS, Johnson MP, Najahi-Missaoui W. Targeted Liposomal Drug Delivery: Overview of the Current Applications and Challenges. Life (Basel) 2024; 14:672. [PMID: 38929656 PMCID: PMC11204409 DOI: 10.3390/life14060672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/14/2024] [Accepted: 05/20/2024] [Indexed: 06/28/2024] Open
Abstract
In drug development, it is not uncommon that an active substance exhibits efficacy in vitro but lacks the ability to specifically reach its target in vivo. As a result, targeted drug delivery has become a primary focus in the pharmaceutical sciences. Since the approval of Doxil® in 1995, liposomes have emerged as a leading nanoparticle in targeted drug delivery. Their low immunogenicity, high versatility, and well-documented efficacy have led to their clinical use against a wide variety of diseases. That being said, every disease is accompanied by a unique set of physiological conditions, and each liposomal product must be formulated with this consideration. There are a multitude of different targeting techniques for liposomes that can be employed depending on the application. Passive techniques such as PEGylation or the enhanced permeation and retention effect can improve general pharmacokinetics, while active techniques such as conjugating targeting molecules to the liposome surface may bring even further specificity. This review aims to summarize the current strategies for targeted liposomes in the treatment of diseases.
Collapse
Affiliation(s)
| | | | - Wided Najahi-Missaoui
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA; (M.S.G.); (M.P.J.)
| |
Collapse
|
5
|
Wong KY, Wong MS, Liu J. Nanozymes for Treating Ocular Diseases. Adv Healthc Mater 2024:e2401309. [PMID: 38738646 DOI: 10.1002/adhm.202401309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/01/2024] [Indexed: 05/14/2024]
Abstract
Nanozymes, characterized by their nanoscale size and enzyme-like catalytic activities, exhibit diverse therapeutic potentials, including anti-oxidative, anti-inflammatory, anti-microbial, and anti-angiogenic effects. These properties make them highly valuable in nanomedicine, particularly ocular therapy, bypassing the need for systemic delivery. Nanozymes show significant promise in tackling multi-factored ocular diseases, particularly those influenced by oxidation and inflammation, like dry eye disease, and age-related macular degeneration. Their small size, coupled with their ease of modification and integration into soft materials, facilitates the effective penetration of ocular barriers, thereby enabling targeted or prolonged therapy within the eye. This review is dedicated to exploring ocular diseases that are intricately linked to oxidation and inflammation, shedding light on the role of nanozymes in managing these conditions. Additionally, recent studies elucidating advanced applications of nanozymes in ocular therapeutics, along with their integration with soft materials for disease management, are discussed. Finally, this review outlines directions for future investigations aimed at bridging the gap between nanozyme research and clinical applications.
Collapse
Affiliation(s)
- Ka-Ying Wong
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
- Centre for Eye and Vision Research (CEVR), 17 W Hong Kong Science Park, Hong Kong
| | - Man-Sau Wong
- Centre for Eye and Vision Research (CEVR), 17 W Hong Kong Science Park, Hong Kong
- Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
- Research Center for Chinese Medicine Innovation, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
- Centre for Eye and Vision Research (CEVR), 17 W Hong Kong Science Park, Hong Kong
| |
Collapse
|
6
|
Huang K, Guo R, Luo H, Liu H, Chen D, Deng T, Li J, He J, Xu Z, Li M, He Q. Mucoadhesive liposomal delivery system synergizing anti-inflammation and anti-oxidation for enhanced treatment against dry eye disease. J Control Release 2024; 368:318-328. [PMID: 38428530 DOI: 10.1016/j.jconrel.2024.02.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/27/2024] [Accepted: 02/27/2024] [Indexed: 03/03/2024]
Abstract
Dry eye disease (DED) is a common and frequent ocular surface disease worldwide, which can cause severe ocular surface discomfort and blurred vision. Inflammation and reactive oxygen species (ROS) play decisive roles in the development of DED. However, existing treatments usually focus on anti-inflammation while ignore the role of ROS in DED. Ever worse, the clinical preparations are easily cleared by nasolacrimal ducts, resulting in poor therapeutic effect. To circumvent these obstacles, here we designed a phenylboronic acid (PBA) modified liposome co-loading immunosuppressant cyclosporin A (CsA) and antioxidant crocin (Cro). The CsA/Cro PBA Lip achieved mucoadhesion through the formation of covalent bonds between PBA and the sialic acid residues on mucin, and consequently improved the retention of drugs on the ocular surface. By inhibiting ROS production and blocking NF-κB inflammatory pathway, CsA/Cro PBA Lip successfully promoted the healing of damaged corneal epithelium, eventually achieving the goal of relieving DED. CsA/Cro PBA Lip is proven a simple yet effective dual-drug delivery system, exhibiting superior antioxidant and anti-inflammatory effects both in vitro and in vivo. This approach holds great potential in the clinical treatment of DED and other related mucosal inflammations.
Collapse
Affiliation(s)
- Kexin Huang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Rong Guo
- Department of Biochemistry and Molecular Biology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu 610041, China
| | - Haoyuan Luo
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Houqin Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Dong Chen
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Tao Deng
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Jiaxin Li
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Jiao He
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Zhuping Xu
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, China.
| | - Man Li
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Qin He
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, Med-X Center for Materials, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
7
|
Wong KY, Wong MS, Liu J. Aptamer-functionalized liposomes for drug delivery. Biomed J 2023; 47:100685. [PMID: 38081386 PMCID: PMC11340590 DOI: 10.1016/j.bj.2023.100685] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/21/2023] [Accepted: 12/05/2023] [Indexed: 07/26/2024] Open
Abstract
Among the various targeting ligands for drug delivery, aptamers have attracted much interest in recent years because of their smaller size compared to antibodies, ease of modification, and better batch-to-batch consistency. In addition, aptamers can be selected to target both known and even unknown cell surface biomarkers. For drug loading, liposomes are the most successful vehicle and many FDA-approved formulations are based on liposomes. In this paper, aptamer-functionalized liposomes for targeted drug delivery are reviewed. We begin with the description of related aptamers selection, followed by methods to conjugate aptamers to liposomes and the fate of such conjugates in vivo. Then a few examples of applications are reviewed. In addition to intravenous injection for systemic delivery and hoping to achieve accumulation at target sites, for certain applications, it is also possible to have aptamer/liposome conjugates applied directly at the target tissue such as intratumor injection and dropping on the surface of the eye by adhering to the cornea. While previous reviews have focused on cancer therapy, the current review mainly covers other applications in the last four years. Finally, this article discusses potential issues of aptamer targeting and some future research opportunities.
Collapse
Affiliation(s)
- Ka-Ying Wong
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Canada; Centre for Eye and Vision Research (CEVR), Hong Kong.
| | - Man-Sau Wong
- Centre for Eye and Vision Research (CEVR), Hong Kong; Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hong Kong; Research Center for Chinese Medicine Innovation, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Canada; Centre for Eye and Vision Research (CEVR), Hong Kong.
| |
Collapse
|
8
|
Lee H, Noh H. Advancements in Nanogels for Enhanced Ocular Drug Delivery: Cutting-Edge Strategies to Overcome Eye Barriers. Gels 2023; 9:718. [PMID: 37754399 PMCID: PMC10529109 DOI: 10.3390/gels9090718] [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: 08/14/2023] [Revised: 08/29/2023] [Accepted: 09/02/2023] [Indexed: 09/28/2023] Open
Abstract
Nanomedicine in gel or particle formation holds considerable potential for enhancing passive and active targeting within ocular drug delivery systems. The complex barriers of the eye, exemplified by the intricate network of closely connected tissue structures, pose significant challenges for drug administration. Leveraging the capability of engineered nanomedicine offers a promising approach to enhance drug penetration, particularly through active targeting agents such as protein peptides and aptamers, which facilitate targeted release and heightened bioavailability. Simultaneously, DNA carriers have emerged as a cutting-edge class of active-targeting structures, connecting active targeting agents and illustrating their potential in ocular drug delivery applications. This review aims to consolidate recent findings regarding the optimization of various nanoparticles, i.e., hydrogel-based systems, incorporating both passive and active targeting agents for ocular drug delivery, thereby identifying novel mechanisms and strategies. Furthermore, the review delves into the potential application of DNA nanostructures, exploring their role in the development of targeted drug delivery approaches within the field of ocular therapy.
Collapse
Affiliation(s)
| | - Hyeran Noh
- Department of Optometry, Seoul National University of Science and Technology, Gongnung-ro 232, Nowon-gu, Seoul 01811, Republic of Korea;
| |
Collapse
|
9
|
Mostafa M, Al Fatease A, Alany RG, Abdelkader H. Recent Advances of Ocular Drug Delivery Systems: Prominence of Ocular Implants for Chronic Eye Diseases. Pharmaceutics 2023; 15:1746. [PMID: 37376194 DOI: 10.3390/pharmaceutics15061746] [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: 05/16/2023] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Chronic ocular diseases can seriously impact the eyes and could potentially result in blindness or serious vision loss. According to the most recent data from the WHO, there are more than 2 billion visually impaired people in the world. Therefore, it is pivotal to develop more sophisticated, long-acting drug delivery systems/devices to treat chronic eye conditions. This review covers several drug delivery nanocarriers that can control chronic eye disorders non-invasively. However, most of the developed nanocarriers are still in preclinical or clinical stages. Long-acting drug delivery systems, such as inserts and implants, constitute the majority of the clinically used methods for the treatment of chronic eye diseases due to their steady state release, persistent therapeutic activity, and ability to bypass most ocular barriers. However, implants are considered invasive drug delivery technologies, especially those that are nonbiodegradable. Furthermore, in vitro characterization approaches, although useful, are limited in mimicking or truly representing the in vivo environment. This review focuses on long-acting drug delivery systems (LADDS), particularly implantable drug delivery systems (IDDS), their formulation, methods of characterization, and clinical application for the treatment of eye diseases.
Collapse
Affiliation(s)
- Mahmoud Mostafa
- Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minya 61519, Egypt
| | - Adel Al Fatease
- Department of Pharmaceutics, College of Pharmacy, King Khalid University, Abha 62223, Saudi Arabia
| | - Raid G Alany
- School of Pharmacy, Kingston University London, Kingston Upon Tames KT1 2EE, UK
- School of Pharmacy, The University of Auckland, Auckland 1010, New Zealand
| | - Hamdy Abdelkader
- Department of Pharmaceutics, College of Pharmacy, King Khalid University, Abha 62223, Saudi Arabia
| |
Collapse
|