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Fang Z, Bi S, Brown JD, Chen J, Pan T. Microfluidics in the eye: a review of glaucoma implants from an engineering perspective. LAB ON A CHIP 2023; 23:4736-4772. [PMID: 37847237 DOI: 10.1039/d3lc00407d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.
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Affiliation(s)
- Zecong Fang
- Bionic Sensing and Intelligence Center (BSIC), Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.
| | - Shuzhen Bi
- Center for Intelligent Medical Equipment and Devices (iMED), University of Science and Technology of China, Suzhou, Jiangsu, 215123, China
| | | | - Junyi Chen
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, 200031, China
| | - Tingrui Pan
- Bionic Sensing and Intelligence Center (BSIC), Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.
- Center for Intelligent Medical Equipment and Devices (iMED), University of Science and Technology of China, Suzhou, Jiangsu, 215123, China
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui, 230026, China
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Taskar PS, Patil A, Lakhani P, Ashour E, Gul W, ElSohly MA, Murphy B, Majumdar S. Δ 9-Tetrahydrocannabinol Derivative-Loaded Nanoformulation Lowers Intraocular Pressure in Normotensive Rabbits. Transl Vis Sci Technol 2019; 8:15. [PMID: 31588378 PMCID: PMC6753841 DOI: 10.1167/tvst.8.5.15] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/10/2019] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Δ9-Tetrahydrocannabinol-valine-hemisuccinate, a hydrophilic prodrug of Δ9-tetrahydrocannabinol, synthesized with the aim of improving the ocular bioavailability of the parent molecule, was investigated in a lipid-based nanoparticle dosage form for ocular delivery. METHODS Solid lipid nanoparticles (SLNs) of Δ9-tetrahydrocannabinol-valine-hemisuccinate and Δ9-tetrahydrocannabinol, along with a nanoemulsion of Δ9-tetrahydrocannabinol-valine-hemisuccinate, were tested for glaucoma management in a normotensive rabbit model by using a multiple-dosing protocol. Marketed formulations of timolol maleate and pilocarpine HCl were also tested for their pharmacodynamic profile, post-single dose administration. RESULTS A peak intraocular pressure (IOP) drop of 30% from baseline was observed in rabbits treated with SLNs loaded with Δ9-tetrahydrocannabinol-valine-hemisuccinate at 90 minutes. Treated eyes of rabbits receiving Δ9-tetrahydrocannabinol-valine-hemisuccinate SLNs had significantly lower IOP than untreated eyes until 360 minutes, whereas the group receiving the emulsion formulation showed a drop in IOP until 90 minutes only. In comparison to marketed pilocarpine and timolol maleate ophthalmic solutions, Δ9-tetrahydrocannabinol-valine-hemisuccinate SLNs produced a greater effect on IOP in terms of both intensity and duration. In terms of tissue concentrations, significantly higher concentrations of Δ9-tetrahydrocannabinol-valine-hemisuccinate were observed in iris-ciliary bodies and retina-choroid with SLNs. CONCLUSION Δ9-Tetrahydrocannabinol-valine-hemisuccinate formulated in a lipid-based nanoparticulate carrier shows promise in glaucoma pharmacotherapy. TRANSLATIONAL RELEVANCE Glaucoma therapies usually focus on decreased aqueous humor production and increased outflow. However, such therapy is not curative, and there lies a need in preclinical research to focus efforts on agents that not only affect the aqueous humor dynamics but also provide neuroprotection. Historically, there have been bench-scale studies looking at retinal ganglion cell death post-axonal injury. However, for a smooth translation of this in vitro activity to the clinic, animal models examining IOP reduction, i.e., connecting the neuroprotective activity to a measurable outcome in glaucoma management (IOP), need to be investigated. This study investigated the IOP reduction efficacy of cannabinoids for glaucoma pharmacotherapy in a normotensive rabbit model, bringing forth a new class of agents with the potential of IOP reduction and improved permeation to the back of the eye, possibly providing neuroprotective benefits in glaucoma management.
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Affiliation(s)
- Pranjal S Taskar
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
| | - Akash Patil
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
| | - Prit Lakhani
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
| | - Eman Ashour
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
| | - Waseem Gul
- ElSohly Laboratories Inc., Oxford, MS, USA
| | - Mahmoud A ElSohly
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
- ElSohly Laboratories Inc., Oxford, MS, USA
| | | | - Soumyajit Majumdar
- Department of Pharmaceutics and Drug Delivery, University of Mississippi, Oxford, MS, USA
- Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS, USA
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Misra SK, Dighe K, Schwartz-Duval AS, Shang Z, Labriola LT, Pan D. In situ plasmonic generation in functional ionic-gold-nanogel scaffold for rapid quantitative bio-sensing. Biosens Bioelectron 2018; 120:77-84. [PMID: 30149216 DOI: 10.1016/j.bios.2018.08.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/21/2018] [Accepted: 08/10/2018] [Indexed: 11/17/2022]
Abstract
Conventional analytical techniques, which have been developed for high sensitivity and selectivity for the detection and quantification of relevant biomarkers, may not be as suitable for medical diagnosis in resource scarce environments as compared to point-of-care devices (POC). We have developed a new reactive sensing material which contains ionic gold entrapped within an agarose gel scaffold for POC quantification of ascorbic acid (AA) in tear fluid. Pathologically elevated concentration of AA in human tear fluid can serve as a biomarker for full-thickness injuries to the ocular surface, which are a medical emergency. This reactive sensing material will undergo colorimetric changes, quantitatively dependent on endogenous bio-reductants that are applied, as the entrapped ionic gold is reduced to form plasmonic nanoparticles. The capacity for this reactive material to function as a plasmonically driven biosensor, called 'OjoGel' (ojo-eye), was demonstrated with the endogenous reducing agent, AA. Through applications of AA of varied concentrations to the OjoGel, we demonstrated a quantitative colorimetric relationship between red (R) hexadecimal values and concentrations of AA in said treatments. This colorimetric relationship is directly resultant of plasmonic gold nanoparticle formation within the OjoGel scaffold. Using a commercially available mobile phone-based Pixel Picker® application, the OjoGel plasmonic sensing platform opens a new avenue for easy-to-use, rapid, and quantitative biosensing with low cost and accurate results.
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Affiliation(s)
- Santosh K Misra
- Department of Bioengineering, Materials Science and Engineering, Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL, USA
| | - Ketan Dighe
- Department of Bioengineering, Materials Science and Engineering, Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL, USA
| | - Aaron S Schwartz-Duval
- Department of Bioengineering, Materials Science and Engineering, Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL, USA
| | - Zaixi Shang
- Department of Bioengineering, Materials Science and Engineering, Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL, USA
| | - Leanne T Labriola
- Ophthalmology Department, Carle Foundation Hospital, Urbana, IL, USA; Surgery Department, University of Illinois College of Medicine, Urbana, IL, USA; Interdisciplinary Health Science Initiative, University of Illinois, Urbana, IL, USA
| | - Dipanjan Pan
- Department of Bioengineering, Materials Science and Engineering, Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL, USA; Carle Illinois College of Medicine, Urbana, IL, USA; Interdisciplinary Health Science Initiative, University of Illinois, Urbana, IL, USA.
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Funke S, Perumal N, Bell K, Pfeiffer N, Grus FH. The potential impact of recent insights into proteomic changes associated with glaucoma. Expert Rev Proteomics 2017; 14:311-334. [PMID: 28271721 DOI: 10.1080/14789450.2017.1298448] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Glaucoma, a major ocular neuropathy, is still far from being understood on a molecular scale. Proteomic workflows revealed glaucoma associated alterations in different eye components. By using state-of-the-art mass spectrometric (MS) based discovery approaches large proteome datasets providing important information about glaucoma related proteins and pathways could be generated. Corresponding proteomic information could be retrieved from various ocular sample species derived from glaucoma experimental models or from original human material (e.g. optic nerve head or aqueous humor). However, particular eye tissues with the potential for understanding the disease's molecular pathomechanism remains underrepresented. Areas covered: The present review provides an overview of the analysis depth achieved for the glaucomatous eye proteome. With respect to different eye regions and biofluids, proteomics related literature was found using PubMed, Scholar and UniProtKB. Thereby, the review explores the potential of clinical proteomics for glaucoma research. Expert commentary: Proteomics will provide important contributions to understanding the molecular processes associated with glaucoma. Sensitive discovery and targeted MS approaches will assist understanding of the molecular interplay of different eye components and biofluids in glaucoma. Proteomic results will drive the comprehension of glaucoma, allowing a more stringent disease hypothesis within the coming years.
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Affiliation(s)
- Sebastian Funke
- a Experimental Ophthalmology , University Medical Center , Mainz , Germany
| | - Natarajan Perumal
- a Experimental Ophthalmology , University Medical Center , Mainz , Germany
| | - Katharina Bell
- a Experimental Ophthalmology , University Medical Center , Mainz , Germany
| | - Norbert Pfeiffer
- a Experimental Ophthalmology , University Medical Center , Mainz , Germany
| | - Franz H Grus
- a Experimental Ophthalmology , University Medical Center , Mainz , Germany
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Kyei S, Koffuor GA, Ramkissoon P, Owusu-Afriyie O. Anti-glaucoma potential of Heliotropium indicum Linn in experimentally-induced glaucoma. EYE AND VISION 2015; 2:16. [PMID: 26605369 PMCID: PMC4657293 DOI: 10.1186/s40662-015-0027-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/08/2015] [Indexed: 01/06/2023]
Abstract
Background Heliotropium indicum is used as a traditional remedy for hypertension in Ghana. The aim of the study was to evaluate the anti-glaucoma potential of an aqueous whole plant extract of H. indicum to manage experimentally-induced glaucoma. Methods The percentage change in intraocular pressure (IOP), after inducing acute glaucoma (15 mLkg−1 of 5 % dextrose, i.v.), in New Zealand White rabbits pretreated with Heliotropium indicum aqueous extract (HIE) (30–300 mgkg−1), acetazolamide (5 mgkg−1), and normal saline (10 mLkg−1) per os were measured. IOPs were also monitored in chronic glaucoma in rabbits (induced by 1 % prednisolone acetate drops, 12 hourly for 21 days) after treatments with the same doses of HIE, acetazolamide, and normal saline for 2 weeks. The anti-oxidant property of the extract was assessed by assaying for glutathione levels in the aqueous humour. Glutamate concentration in the vitreous humour was also determined using ELISA technique. Histopathological assessment of the ciliary bodies was made. Results The extract significantly reduced intraocular pressure (p ≤ 0.05–0.001) in acute and chronic glaucoma, preserved glutathione levels and glutamate concentration (p ≤ 0.01–0.001). Histological assessment of the ciliary body showed a decrease in inflammatory infiltration in the extract and acetazolamide-treated group compared with the normal saline-treated group. Conclusion The aqueous whole plant extract of Heliotropium indicum has ocular hypotensive, anti-oxidant and possible neuro-protective effects, which therefore underscore its plausible utility as an anti-glaucoma drug with further investigation.
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Affiliation(s)
- Samuel Kyei
- Discipline of Optometry, School of Health Sciences, College of Health Sciences, University of KwaZulu- Natal, Durban, South Africa ; Department of Optometry, School of Physical Sciences, University of Cape-Coast, Cape-Coast, Ghana
| | - George Asumeng Koffuor
- Discipline of Optometry, School of Health Sciences, College of Health Sciences, University of KwaZulu- Natal, Durban, South Africa ; Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Paul Ramkissoon
- Discipline of Optometry, School of Health Sciences, College of Health Sciences, University of KwaZulu- Natal, Durban, South Africa
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Grus FH, Joachim SC, Pfeiffer N. Proteomics in ocular fluids. Proteomics Clin Appl 2007; 1:876-88. [DOI: 10.1002/prca.200700105] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Indexed: 12/14/2022]
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Scholl HPN, Fleckenstein M, Krohne TU, Holz FG. Klassifikation biomedizinischer Forschungsberichte als Grundlage evidenzbasierter Medizin in der Augenheilkunde. Ophthalmologe 2005; 102:1152-61. [PMID: 16283184 DOI: 10.1007/s00347-005-1293-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Evidence-based medicine requires careful appraisal of published data derived from experimental and clinical studies. Based on classification of biomedical research reports, evidence levels can be determined and recommendations for therapeutic decisions can be made. METHODS A classification system for clinical studies was developed. It was evaluated in classifying the reports published in Der Ophthalmologe during 2003-2004 (study design: descriptive cross-sectional study, case series). RESULTS In the 2-year interval, 70 longitudinal and 95 cross-sectional studies were published. The vast majority of the longitudinal studies were interventional cohort studies. Not considering case reports, 73% of the original articles were longitudinal prospective studies, 1% were retrospective (case-control) studies, and 26% were cross-sectional studies. CONCLUSIONS The study design of all published articles could be classified using the classification system. This classification system proves to be applicable in the context of clinical studies in ophthalmology and may be helpful in the process of critical appraisal of the literature and synthesis of clinical evidence and an evidence-based recommendation.
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