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Keywords = corneal permeability study

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16 pages, 1291 KiB  
Review
Pellucid Marginal Degeneration: A Comprehensive Review of Pathophysiology, Diagnosis, and Management Strategies
by Michael Tsatsos, Konstantina Koulotsiou, Ioannis Giachos, Ioannis Tsinopoulos and Nikolaos Ziakas
J. Clin. Med. 2025, 14(15), 5178; https://doi.org/10.3390/jcm14155178 - 22 Jul 2025
Viewed by 364
Abstract
Purpose: Pellucid Marginal Degeneration (PMD) is a rare ectatic corneal disorder characterized by inferior peripheral thinning and significant irregular astigmatism. Despite its clinical similarities to keratoconus, PMD presents unique diagnostic and therapeutic challenges. This review aims to provide a comprehensive update on the [...] Read more.
Purpose: Pellucid Marginal Degeneration (PMD) is a rare ectatic corneal disorder characterized by inferior peripheral thinning and significant irregular astigmatism. Despite its clinical similarities to keratoconus, PMD presents unique diagnostic and therapeutic challenges. This review aims to provide a comprehensive update on the pathophysiology, clinical features, diagnostic approaches, and management strategies for PMD, emphasizing the latest advancements in treatment options. Methods: A systematic literature search was performed in MEDLINE (via PubMed), Google Scholar, and Scopus up to February 2025 using the terms: “pellucid marginal degeneration,” “PMD,” “ectatic corneal disorders,” “keratoplasty in PMD,” “corneal cross-linking in PMD,” “ICRS in PMD,” “toric IOL PMD” and their Boolean combinations (AND/OR). The search was restricted to English-language studies involving human subjects, including case reports, case series, retrospective studies, clinical trials, and systematic reviews. A total of 76 studies met the inclusion criteria addressing treatment outcomes in PMD. Results: PMD is characterized by a crescent-shaped band of inferior corneal thinning, leading to high irregular astigmatism and reduced visual acuity. Diagnosis relies on advanced imaging techniques such as Scheimpflug-based corneal tomography, which reveals the characteristic “crab-claw” pattern. Conservative management includes rigid gas-permeable (RGP) lenses and scleral lenses, which provide effective visual rehabilitation in mild to moderate cases. Surgical options, such as CXL, ICRS, and toric IOLs, are reserved for advanced cases, with varying degrees of success. Newer techniques such as CAIRS, employing donor tissue instead of synthetic rings, show promising outcomes in corneal remodeling with potentially improved biocompatibility. Penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) remain definitive treatments for severe PMD, though they are associated with significant risks, including graft rejection and postoperative astigmatism. Conclusions: PMD is a complex and progressive corneal disorder that requires a tailored approach to management. Early diagnosis and intervention are critical to optimizing visual outcomes. While conservative measures are effective in mild cases, surgical interventions offer promising results for advanced disease. Further research is needed to refine treatment protocols and improve long-term outcomes for patients with PMD. Full article
(This article belongs to the Special Issue New Insights into Corneal Disease and Transplantation)
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21 pages, 7194 KiB  
Article
Quality by Design (QbD)-Based Development of a Self-Nanoemulsifying Drug Delivery System for the Ocular Delivery of Flurbiprofen
by Ju-Hwan Jeong, Tae-Han Yoon, Si-Won Ryu, Min-Gyeong Kim, Gu-Hae Kim, Ye-Jin Oh, Su-Jeong Lee, Na-Woon Kwak, Kyu-Ho Bang and Kyeong-Soo Kim
Pharmaceutics 2025, 17(5), 629; https://doi.org/10.3390/pharmaceutics17050629 - 9 May 2025
Viewed by 707
Abstract
Objectives: In this study, Quality by Design (QbD) was used to develop an optimized self-nanoemulsifying drug delivery system (SNEDDS) as an ophthalmic formulation of flurbiprofen (FLU). Using a Box–Behnken design (BBD), an optimal SNEDDS composition was crafted, targeting enhanced corneal permeability and [...] Read more.
Objectives: In this study, Quality by Design (QbD) was used to develop an optimized self-nanoemulsifying drug delivery system (SNEDDS) as an ophthalmic formulation of flurbiprofen (FLU). Using a Box–Behnken design (BBD), an optimal SNEDDS composition was crafted, targeting enhanced corneal permeability and increased bioavailability of the drug. Methods: The levels of each factor(X) were established using a pseudo-ternary diagram, and the Box-Behnken design (BBD) was used to evaluate the components of oil (18.9 mg), surfactant (70.7 mg), and co-surfactant (10.0 mg) to optimize the SNEDDS formulation. The response(Y) considered were particle size, polydispersity index (PDI), transmittance, and stability. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were used to analyze the particle size and morphology. In vitro and ex vivo diffusion tests were conducted to assess drug flux and permeability. Result: Using a response optimization tool, the values of each X factor were optimized to achieve a small particle size (nm), a low polydispersity index (PDI), and high transmittance (%), resulting in a formulation prepared with 18.9 mg of oil, 70.7 mg of surfactant, and 10.0 mg of co-surfactant. The optimized SNEDDS exhibited a small particle size of 24.89 nm, a minimal PDI of 0.068, and a high transmittance of 74.85%. A transmission electron microscopy (TEM) analysis confirmed the presence of uniform spherical nanoemulsion droplets with an observed mean diameter of less than 25 nm, corroborating the dynamic light scattering (DLS) measurements. Furthermore, the SNEDDS demonstrated improved stability under the stress conditions of heating–cooling cycles, with no phase separation, creaming, or caking observed and no differences in its particle size, PDI, or transmittance. In vitro and ex vivo diffusion tests demonstrated that the flux of the optimized SNEDDS (2.723 ± 0.133 mg/cm2, 5.446 ± 0.390 μg/cm2) was about 2.5 and 4 times higher than that of the drug dispersion, and the initial diffusion was faster, which is suitable for the characteristics of eye drops. Conclusions: Therefore, the formulation of a flurbiprofen-loaded SNEDDS (FLU-SNE) was successfully optimized using the QbD approach. The optimized FLU-SNE exhibited excellent stability and enhanced permeability, suggesting its potential effectiveness in treating various ocular inflammations, including uveitis and cystoid macular edema. Full article
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18 pages, 8813 KiB  
Article
Chitosan-TPP Nanogels for Ocular Delivery of Folic Acid: Release Profile, Corneal Permeation, and Mucoadhesion Assessment
by Sebastián G. Bruno, Sofía M. Martínez, Camila Costa Gobbato, Daniela A. Quinteros, Agustina Alaimo and Oscar E. Pérez
Pharmaceutics 2025, 17(4), 424; https://doi.org/10.3390/pharmaceutics17040424 - 27 Mar 2025
Cited by 1 | Viewed by 701
Abstract
Background: Folic acid (FA) is essential for cellular functions but has limited ocular bioavailability, restricting its therapeutic effectiveness. Objective: To develop chitosan (CS)-based nanogels (NGs) for FA transport and release, with corneal permeation evaluation. Methods: NGs’ hydrodynamic diameter (Ho) and [...] Read more.
Background: Folic acid (FA) is essential for cellular functions but has limited ocular bioavailability, restricting its therapeutic effectiveness. Objective: To develop chitosan (CS)-based nanogels (NGs) for FA transport and release, with corneal permeation evaluation. Methods: NGs’ hydrodynamic diameter (Ho) and polydispersity index (PdI) were determined using dynamic light scattering (DLS). CS-FA interaction was confirmed by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) was applied for the dehydrated material characterization. Scanning electron microscopy (SEM) was used to evaluate the NGs ultraestructure. In vitro drug release studies were performed using a modified Franz diffusion cell, and the release profile was fitted to obtain kinetics parameters. Mucoadhesion properties were evaluated through ζ-potential measurements. Ex vivo corneal permeation studies were conducted in rabbit corneas to compare the permeability of FA contained in NGs. Results: NGs presented a Ho of 312.4 ± 8.2 nm and a PdI of 0.28 ± 0.04. SEM imaging revealed spherical morphologies with minor variations in size and shape induced by FA. Lyophilized and resuspended NGs exhibited a 6.8% increase in Ho and a PdI rise to 0.42, indicating slight aggregation. In vitro drug release studies demonstrated sustained FA release, as determined by the Higuchi model. Mucoadhesion studies showed a decrease in ζ-potential from +36.9 to +18.1 mV, confirming electrostatic interactions with mucin. Ex vivo corneal permeation studies indicated that encapsulated FA permeated 2.6 times slower than free FA, suggesting sustained release. Conclusions: our findings demonstrate the potential of nanostructures in the form of NGs to enhance FA-loaded ocular delivery and bioavailability. Full article
(This article belongs to the Special Issue Recent Advances in Chitosan-Based Nanoparticles for Drug Delivery)
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13 pages, 6924 KiB  
Article
Evaluation of Nano-Niclosamide in Killing Demodex folliculorum In Vitro and the Potential Application in Ocular Surface
by Jiani Li, Panqin Ma, Shujia Guo, Danyi Qin, Yuqian Wang, Yuwen Liu, Zixuan Yang, Caihong Huang, Yi Han and Zuguo Liu
Pharmaceutics 2025, 17(3), 332; https://doi.org/10.3390/pharmaceutics17030332 - 4 Mar 2025
Viewed by 1091
Abstract
Background/Objectives: Blepharitis is a condition often caused by Demodex folliculorum infestations, resulting in significant ocular discomfort and surface damage. Current treatments offer only temporary relief and fail to eliminate mites effectively. This study evaluates nano-niclosamide (nano-NCL), a lipophilic nanosuspension designed to enhance solubility [...] Read more.
Background/Objectives: Blepharitis is a condition often caused by Demodex folliculorum infestations, resulting in significant ocular discomfort and surface damage. Current treatments offer only temporary relief and fail to eliminate mites effectively. This study evaluates nano-niclosamide (nano-NCL), a lipophilic nanosuspension designed to enhance solubility and permeability, for targeting Demodex folliculorum. Methods: Nano-NCL was characterized by particle size, zeta potential, transmission electron microscopy, pH measurement, bacterial culture, and HPLC. Viable Demodex mites were collected from patients’ eyelashes and assigned to six treatment groups: DDW, F127, 0.15% nano-NCL, 0.3% nano-NCL, 20% TTO, and Okra. Mite survival was analyzed using Kaplan–Meier curves. The ocular surface safety was assessed via slit-lamp examination, corneal fluorescein staining, and in vivo confocal microscopy. Results: The nano-NCL particles are uniformly rod-shaped, approximately 291 nm in size, and exhibit good stability, remaining suspended in various media for up to 20 days. The formulation has a stable pH of 6 and demonstrated no bacterial growth, indicating sterility and suitability for clinical use. In vitro, both 0.15% (w/v) and 0.30% (w/v) nano-NCL significantly reduced Demodex survival, with mortality rates ranging from 70.6% to 92.3% within 2 h. Safety evaluations showed minimal corneal staining and inflammation. Notably, 0.15% nano-NCL displayed efficacy comparable to that of 20% tea tree oil (TTO) and Okra, which are established anti-Demodex treatments. Conclusions: Nano-NCL, particularly at 0.15%, rapidly eliminates mites while maintaining excellent ocular tolerability, making it a promising treatment for Demodex-related ocular surface diseases. Full article
(This article belongs to the Special Issue Nanoparticles for Local Drug Delivery)
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18 pages, 8963 KiB  
Article
Influence of Different Cationic Polymer-Based Micelles on the Corneal Behavior and Anti-Cataract Effect of Diosmetin
by Jing Zhang, Min Zha, Anping Wan, Satya Siva Kishan Yalamarty, Nina Filipczak and Xiang Li
Pharmaceutics 2025, 17(3), 302; https://doi.org/10.3390/pharmaceutics17030302 - 25 Feb 2025
Cited by 2 | Viewed by 744
Abstract
Background Despite many studies on polymer-incorporated nanocarriers for ophthalmic drug delivery, few have thoroughly explored the relationship between coating composition and performance. This study aimed to evaluate the effects of three commonly used cationic polymers—distearoyl phosphatidylethanolamine-polyethylene glycol 1000-poly(amidoamine) (DSPE-PEG1000-PAMAM), trimethyl chitosan (TMC), and [...] Read more.
Background Despite many studies on polymer-incorporated nanocarriers for ophthalmic drug delivery, few have thoroughly explored the relationship between coating composition and performance. This study aimed to evaluate the effects of three commonly used cationic polymers—distearoyl phosphatidylethanolamine-polyethylene glycol 1000-poly(amidoamine) (DSPE-PEG1000-PAMAM), trimethyl chitosan (TMC), and (2,3-dioleoyloxypropyl) trimethylammonium chloride (DOTAP)—on the corneal behaviors and anti-cataract efficacy of diosmetin (DIO)-loaded micelles (D-M-P, D-M-T, and D-M-D, respectively). Methods The DIO-loaded micelles were prepared using the thin-film dispersion method and incorporated with the three polymers through hydrophobic interactions and electrostatic adsorption. Structural characterization was demonstrated by TEM imaging and particle size analyzer. In vitro release behavior was detected by the dialysis method. Cell viability of D-M-P, D-M-T, and D-M-D on L929 cells was detected by CCK-8 assays, with cellular uptake performed using coumarin 6 as the fluorescence indicator. Precorneal retention behaviors of these three vesicles were observed by In Vivo Imaging System. Transcorneal permeability was determined by modified Franz diffusion method and the permeation routes of the vesicles are investigated. Selenite-induced cataract model was established. The anti-cataract effects of three different DIO-loaded micelles were evaluated by the observation of lens opacity and antioxidant enzyme activities. Eye Irritation of the DIO in different preparations was estimated using the Draize test, along with H&E staining of the corneas. Results Structural characterization of DIO-loaded micelles revealed that the vesicles were spherical, with a uniform size distribution of around 28 nm, a similar surface potential of approximately 6.0 mV, and a high DIO entrapment efficiency of about 95%. Compared to the DIO suspension, all three formulations exhibited a significant sustained-release effect. They showed no signs of irritation and demonstrated increased IC50 values in L929 cells, indicating improved biocompatibility. Cellular uptake in human lens epithelial cells (HLECs) was assessed using confocal laser scanning microscopy. C-M-T displayed the highest fluorescence signals, with a cellular internalization 3.2 times greater than that of the solution group. Both C-M-T and C-M-P enhanced vesicle retention on the corneal surface by at least 47.8% compared to the Cou-6 solution. Furthermore, TMC facilitated the paracellular transport of vesicles into the deepest layers of the cornea and delivered DIO across the cornea, with a Papp value 3.11 times and 1.49 times those of D-M-D and D-M-P, respectively. In terms of therapeutic efficacy, D-M-T demonstrated the most significant attenuation of lens opacity, along with enhanced antioxidant enzyme activities and inhibition of lipid peroxidation. Conclusion The modification of micelle vesicles with different cationic polymers significantly influences their performance in ocular drug delivery. Among the tested formulations, D-M-T stands out due to its multiple advantages, including enhanced transcorneal drug delivery, therapeutic efficacy for DIO, and safety, making it the most promising candidate for ophthalmic applications. Full article
(This article belongs to the Special Issue Polymer-Based Delivery System)
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15 pages, 1256 KiB  
Article
Pesticides’ Cornea Permeability—How Serious Is This Problem?
by Anna W. Sobańska, Andrzej M. Sobański and Karolina Wanat
Pharmaceutics 2025, 17(2), 156; https://doi.org/10.3390/pharmaceutics17020156 - 24 Jan 2025
Viewed by 766
Abstract
Background: A total of 348 pesticides from different chemical families (carbamates, organochlorines organophosphorus compounds, pyrethroids, triazines and miscellaneous) were investigated in the context of their cornea permeability and potential to cause eye corrosion. Methods: Multivariate models of cornea permeability based on compounds whose [...] Read more.
Background: A total of 348 pesticides from different chemical families (carbamates, organochlorines organophosphorus compounds, pyrethroids, triazines and miscellaneous) were investigated in the context of their cornea permeability and potential to cause eye corrosion. Methods: Multivariate models of cornea permeability based on compounds whose cornea permeability has been determined experimentally were proposed. The models, applicable to compounds across a relatively broad lipophilicity range (e.g., pesticides with octanol–water partition coefficient log P up to ca. 8), assume a reverse-parabolic relationship between cornea permeability and lipophilicity, expressed as XLOGP3; other main descriptors present in the models are log D at pH 7.4 and polar surface area (PSA). Results: It appears that the trans-corneal transport of all studied pesticides is possible to some degree; however, it is more difficult for the majority of highly lipophilic pesticides from the organochlorine and pyrethroid families. The same set of 348 pesticides was also evaluated for their eye-corrosive potential using novel artificial neural network models involving simple physico-chemical properties of the compounds (lipophilicity, aqueous solubility, polar surface area, H-bond donor and acceptor count and the count of atoms such as N, NH, O, P, S and halogens). Conclusions: It was concluded that eye corrosion is an issue, especially among the pesticides from organochlorine and organophosphorus families. Full article
(This article belongs to the Special Issue Transport of Drugs through Biological Barriers—an Asset or Risk)
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15 pages, 3230 KiB  
Article
Enhanced Ocular Bioavailability and Prolonged Duration via Hydrophilic Surface Nanocomposite Vesicles for Topical Drug Administration
by Sa Huang, Yuan Xu, Yingyao Luo, Zhijiong Wang, Fan Li, Zhenmiao Qin and Junfeng Ban
Pharmaceutics 2024, 16(12), 1496; https://doi.org/10.3390/pharmaceutics16121496 - 21 Nov 2024
Cited by 1 | Viewed by 1209
Abstract
Background: Internal ocular diseases, such as macular edema, uveitis, and diabetic macular edema require precise delivery of therapeutic agents to specific regions within the eye. However, the eye’s complex anatomical structure and physiological barriers present significant challenges to drug penetration and distribution. Traditional [...] Read more.
Background: Internal ocular diseases, such as macular edema, uveitis, and diabetic macular edema require precise delivery of therapeutic agents to specific regions within the eye. However, the eye’s complex anatomical structure and physiological barriers present significant challenges to drug penetration and distribution. Traditional eye drops suffer from low bioavailability primarily due to rapid clearance mechanisms. Methods: The novel ocular drug delivery system developed in this study utilizes poly(lactic-co-glycolic acid) (PLGA) nanoparticles modified with cell-penetrating peptides (CPPs). In vitro drug release studies were conducted to evaluate the sustained-release properties of the nanoparticles. Ex vivo experiments using MDCK cells assessed corneal permeability and uptake efficiency. Additionally, in vivo studies were performed in rabbit eyes to determine the nanoparticles’ resistance to elimination by tears and their retention time in the aqueous humor. Results: In vitro drug release studies demonstrated superior sustained-release properties of the nanoparticles. Ex vivo experiments revealed enhanced corneal permeability and increased uptake efficiency by MDCK cells. In vivo studies in rabbit eyes confirmed the nanoparticles’ resistance to elimination by lacrimal fluid and their ability to extend retention time in the aqueous humor. CPP modification significantly improved ocular retention, corneal penetration, and cellular endocytosis efficiency. Conclusions: The CPP-modified PLGA nanoparticles provide an effective and innovative solution for ocular drug delivery, offering improved bioavailability, prolonged retention, and enhanced drug penetration, thereby overcoming the challenges of traditional intraocular drug administration methods. Full article
(This article belongs to the Special Issue Polymer-Based Delivery System)
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20 pages, 4286 KiB  
Article
Chitosan and Anionic Solubility Enhancer Sulfobutylether-β-Cyclodextrin-Based Nanoparticles as Dexamethasone Ophthalmic Delivery System for Anti-Inflammatory Therapy
by Giuseppe Francesco Racaniello, Gennaro Balenzano, Ilaria Arduino, Rosa Maria Iacobazzi, Antonio Lopalco, Angela Assunta Lopedota, Hakon Hrafn Sigurdsson and Nunzio Denora
Pharmaceutics 2024, 16(2), 277; https://doi.org/10.3390/pharmaceutics16020277 - 16 Feb 2024
Cited by 7 | Viewed by 2804
Abstract
Cataract surgery interventions are constantly increasing, particularly among adult and elderly patients. This type of surgery can lead to inflammatory states of the ocular anterior segment (AS), usually healed via postoperative treatment with dexamethasone (DEX)-containing eye drops. The application of eye drops is [...] Read more.
Cataract surgery interventions are constantly increasing, particularly among adult and elderly patients. This type of surgery can lead to inflammatory states of the ocular anterior segment (AS), usually healed via postoperative treatment with dexamethasone (DEX)-containing eye drops. The application of eye drops is challenging due to the high number of daily administrations. In this study, mucoadhesive nanoparticles (NPs) were formulated to improve the residence time of DEX on the corneal mucosa, enhancing the drug’s solubility and bioavailability. The NPs were generated using an ionotropic gelation technique, exploiting the interaction between the cationic group of chitosan (CS) and the anionic group of sulfobutylether-β-cyclodextrin (SBE-β-CD). The formation of the inclusion complex and its stoichiometry were studied through phase solubility studies, Job’s plot method, and Bi-directional transport studies on MDCKII-MDR1. The obtained NPs showed good chemical and physical characteristics suitable for drug loading and subsequent testing on animal mucosa. The DEX-loaded CS/SBE-β-CD NPs exhibited a prolonged residence time on animal mucosa and demonstrated enhanced drug permeability through the corneal membrane, showing a sustained release profile. The developed NPs posed no irritation or toxicity concerns upon local administration, making them an optimal and innovative drug delivery system for inflammatory AS diseases treatment. Full article
(This article belongs to the Special Issue Development of Chitosan/Cyclodextrins in Drug Delivery Field)
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16 pages, 2828 KiB  
Article
Polymer Nanoparticles with 2-HP-β-Cyclodextrin for Enhanced Retention of Uptake into HCE-T Cells
by Zhenmiao Qin, Baohua Li, Qiyi Deng, Yifeng Wen, Shiquan Feng, Chengcheng Duan, Beicheng Zhao, Hailong Li, Yanan Gao and Junfeng Ban
Molecules 2024, 29(3), 658; https://doi.org/10.3390/molecules29030658 - 31 Jan 2024
Cited by 9 | Viewed by 1824
Abstract
Triamcinolone acetonide (TA), a medium-potency synthetic glucocorticoid, is primarily employed to treat posterior ocular diseases using vitreous injection. This study aimed to design novel ocular nanoformulation drug delivery systems using PLGA carriers to overcome the ocular drug delivery barrier and facilitate effective delivery [...] Read more.
Triamcinolone acetonide (TA), a medium-potency synthetic glucocorticoid, is primarily employed to treat posterior ocular diseases using vitreous injection. This study aimed to design novel ocular nanoformulation drug delivery systems using PLGA carriers to overcome the ocular drug delivery barrier and facilitate effective delivery into the ocular tissues after topical administration. The surface of the PLGA nanodelivery system was made hydrophilic (2-HP-β-CD) through an emulsified solvent volatilization method, followed by system characterization. The mechanism of cellular uptake across the corneal epithelial cell barrier used rhodamine B (Rh-B) to prepare fluorescent probes for delivery systems. The triamcinolone acetonide (TA)-loaded nanodelivery system was validated by in vitro release behavior, isolated corneal permeability, and in vivo atrial hydrodynamics. The results indicated that the fluorescent probes, viz., the Rh-B-(2-HP-β-CD)/PLGA NPs and the drug-loaded TA-(2-HP-β-CD)/PLGA NPs, were within 200 nm in size. Moreover, the system was homogeneous and stable. The in vitro transport mechanism across the epithelial barrier showed that the uptake of nanoparticles was time-dependent and that NPs were actively transported across the epithelial barrier. The in vitro release behavior of the TA-loaded nanodelivery systems revealed that (2-HP-β-CD)/PLGA nanoparticles could prolong the drug release time to up to three times longer than the suspensions. The isolated corneal permeability demonstrated that TA-(2-HP-β-CD)/PLGA NPs could extend the precorneal retention time and boost corneal permeability. Thus, they increased the cumulative release per unit area 7.99-fold at 8 h compared to the suspension. The pharmacokinetics within the aqueous humor showed that (2-HP-β-CD)/PLGA nanoparticles could elevate the bioavailability of the drug, and its Cmax was 51.91 times higher than that of the triamcinolone acetonide aqueous solution. Therefore, (2-HP-β-CD)/PLGA NPs can potentially elevate transmembrane uptake, promote corneal permeability, and improve the bioavailability of drugs inside the aqueous humor. This study provides a foundation for future research on transocular barrier nanoformulations for non-invasive drug delivery. Full article
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14 pages, 3076 KiB  
Article
A Comparative Pharmacokinetic Study for Cysteamine-Containing Eye Drops as an Orphan Topical Therapy in Cystinosis
by Anita Csorba, Gábor Katona, Mária Budai-Szűcs, Diána Balogh-Weiser, Péter Molnár, Erika Maka, Adrienn Kazsoki, Márton Vajna, Romána Zelkó, Zoltán Zsolt Nagy and György T. Balogh
Int. J. Mol. Sci. 2024, 25(3), 1623; https://doi.org/10.3390/ijms25031623 - 28 Jan 2024
Viewed by 2285
Abstract
Cystinosis is a low-prevalence lysosomal storage disease. The pathomechanism involves abnormal functioning of the cystinosine lysosomal cystine transporter (CTNS), causing intraliposomal accumulation of the amino acid cysteine disulfide, which crystallizes and deposits in several parts of the body. The most common ophthalmic complication [...] Read more.
Cystinosis is a low-prevalence lysosomal storage disease. The pathomechanism involves abnormal functioning of the cystinosine lysosomal cystine transporter (CTNS), causing intraliposomal accumulation of the amino acid cysteine disulfide, which crystallizes and deposits in several parts of the body. The most common ophthalmic complication of cystinosis is the deposition of “gold dust” cystine crystals on the cornea, which already occurs in infancy and leads to severe photosensitivity and dry eyes as it gradually progresses with age. In the specific treatment of cystinosis, preparations containing cysteamine (CYA) are used. The availability of commercialized eyedrops for the targeted treatment is scarce, and only Cystadrops® are commercially available with strong limitations. Thus, magistral CYA-containing compounded eyedrops (CYA-CED) could have a key role in patient care; however, a rationally designed comprehensive study on the commercialized and magistral products is still missing. This work aims to build up a comprehensive study about commercialized and magistral CYA eye drops, involving pharmacokinetic and physicochemical characterization (applying mucoadhesivity, rheology test, investigation of drug release, and parallel artificial membrane permeability assays), as well as ex vivo tests, well supported by statistical analysis. Full article
(This article belongs to the Section Molecular Pharmacology)
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20 pages, 8957 KiB  
Article
Exploring the Ocular Absorption Pathway of Fasudil Hydrochloride towards Developing a Nanoparticulate Formulation with Improved Performance
by Barzan Osi, Ali A. Al-Kinani, Zinah K. Al-Qaysi, Mouhamad Khoder and Raid G. Alany
Pharmaceutics 2024, 16(1), 112; https://doi.org/10.3390/pharmaceutics16010112 - 15 Jan 2024
Cited by 8 | Viewed by 2281
Abstract
Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and [...] Read more.
Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and canal of Schlemm’s aqueous humor outflow. This study aims to investigate the ocular absorption pathway of Fasudil hydrochloride and, subsequently, develop a nanoparticle-based delivery system for enhanced corneal absorption. Employing the ionic gelation method and statistical experimental design, the factors influencing chitosan nanoparticle (Cs NP) characteristics and performance were explored. Fasudil in vitro release and ex vivo permeation studies were performed, and Cs NP ocular tolerability and cytotoxicity on human lens epithelial cells were evaluated. Permeation studies on excised bovine eyes revealed significantly higher Fasudil permeation through the sclera compared to the cornea (370.0 μg/cm2 vs. 96.8 μg/cm2, respectively). The nanoparticle size (144.0 ± 15.6 nm to 835.9 ± 23.4 nm) and entrapment efficiency range achieved (17.2% to 41.4%) were predominantly influenced by chitosan quantity. Cs NPs showed a substantial improvement in the permeation of Fasudil via the cornea, along with slower release compared to the Fasudil aqueous solution. The results from the Hen’s Egg Test Chorioallantoic Membrane (HET-CAM) and Bovine Corneal Opacity and Permeability (BCOP) tests indicated good conjunctival and corneal biocompatibility of the formulated chitosan nanoparticles, respectively. Lens epithelial cells displayed excellent tolerance to low concentrations of these nanoparticles (>94% cell viability). To the best of our knowledge, this is the first report on the ocular absorption pathway of topically applied Fasudil hydrochloride where the cornea has been identified as a potential barrier that could be overcome using Cs NPs. Full article
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13 pages, 5886 KiB  
Article
Electrospun Nanofiber Membrane for Cultured Corneal Endothelial Cell Transplantation
by Euisun Song, Karen M. Chen, Mathew S. Margolis, Thitima Wungcharoen, Won-Gun Koh and David Myung
Bioengineering 2024, 11(1), 54; https://doi.org/10.3390/bioengineering11010054 - 5 Jan 2024
Cited by 3 | Viewed by 2708
Abstract
The corneal endothelium, comprising densely packed corneal endothelial cells (CECs) adhering to Descemet’s membrane (DM), plays a critical role in maintaining corneal transparency by regulating water and ion movement. CECs have limited regenerative capacity within the body, and globally, there is a shortage [...] Read more.
The corneal endothelium, comprising densely packed corneal endothelial cells (CECs) adhering to Descemet’s membrane (DM), plays a critical role in maintaining corneal transparency by regulating water and ion movement. CECs have limited regenerative capacity within the body, and globally, there is a shortage of donor corneas to replace damaged corneal endothelia. The development of a carrier for cultured CECs may address this worldwide clinical need. In this study we successfully manufactured a gelatin nanofiber membrane (gelNF membrane) using electrospinning, followed by crosslinking with glutaraldehyde (GA). The fabricated gelNF membrane exhibited approximately 80% transparency compared with glass and maintained a thickness of 20 µm. The gelNF membrane demonstrated desirable permeability and degradability for a Descemet’s membrane analog. Importantly, CECs cultured on the gelNF membrane at high densities showed no cytotoxic effects, and the expression of key CEC functional biomarkers was verified. To assess the potential of this gelNF membrane as a carrier for cultured CEC transplantation, we used it to conduct Descemet’s membrane endothelial keratoplasty (DMEK) on rabbit eyes. The outcomes suggest this gelNF membrane holds promise as a suitable carrier for cultured CEC transplantation, offering advantages in terms of transparency, permeability, and sufficient mechanical properties required for successful transplantation. Full article
(This article belongs to the Special Issue Bioengineering and the Eye—2nd Edition)
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17 pages, 3963 KiB  
Article
TGF-β2 Induces Epithelial–Mesenchymal Transitions in 2D Planer and 3D Spheroids of the Human Corneal Stroma Fibroblasts in Different Manners
by Araya Umetsu, Yosuke Ida, Tatsuya Sato, Masato Furuhashi, Hiroshi Ohguro and Megumi Watanabe
Biomedicines 2023, 11(9), 2513; https://doi.org/10.3390/biomedicines11092513 - 12 Sep 2023
Cited by 3 | Viewed by 2097
Abstract
To examine the epithelial–mesenchymal transition (EMT) that is induced on the human corneal stroma, two- and three-dimensional (2D and 3D) cultures of human corneal stroma fibroblasts (HCSFs) were used. In this study, HCSF 2D monolayers and 3D spheroids were characterized by (1) scanning [...] Read more.
To examine the epithelial–mesenchymal transition (EMT) that is induced on the human corneal stroma, two- and three-dimensional (2D and 3D) cultures of human corneal stroma fibroblasts (HCSFs) were used. In this study, HCSF 2D monolayers and 3D spheroids were characterized by (1) scanning electron microscopy (SEM), (2) trans-endothelial electrical resistance (TEER) measurements and fluorescein isothiocyanate (FITC)-dextran permeability, (3) cellular metabolic measurements, (4) the physical properties of 3D HCSF spheroids, and (5) the extracellular matrix (ECM) molecule gene expressions, including collagen (COL) 1, 4 and 6, and fibronectin (FN), a tissue inhibitor of metalloproteinase (TIMP) 1–4, matrix metalloproteinase (MMP) 2, 3, 9 and 14, and several endoplasmic reticulum (ER) stress-related factors. In the 2D HCSFs, TGF-β2 concentration-dependently generated (1) a considerable increase in ECM deposits revealed by SEM, (2) an increase in TEER values and a decrease in FITC-dextran permeability, (3) increases in both mitochondrial and glycolytic functions, and a substantial upregulation of COL1, COL4, FN, αSMA, TIMP1, TIMP, and most ER stress-related genes and the downregulation of COL6 and MMP3. In the case of 3D spheroids, TGF-β2 induced the downsizing and stiffening of 3D spheroids and the upregulation of COL6, MMP14, and most ER stress-related genes. These findings suggest that TGF-β2 significantly induced a number of EMT-associated biological events including planar proliferation, cellular metabolic functions, and the production of ECM molecules in the 2D cultured HCSF cells, but these effects were significantly less pronounced in the case of 3D HCSF spheroids. Full article
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22 pages, 4014 KiB  
Article
Corneal Permeability and Uptake of Twenty-Five Drugs: Species Comparison and Quantitative Structure–Permeability Relationships
by Cleildo P. Santana, Brock A. Matter, Madhoosudan A. Patil, Armando Silva-Cunha and Uday B. Kompella
Pharmaceutics 2023, 15(6), 1646; https://doi.org/10.3390/pharmaceutics15061646 - 2 Jun 2023
Cited by 20 | Viewed by 3211
Abstract
The purpose of this study was to determine corneal permeability and uptake in rabbit, porcine, and bovine corneas for twenty-five drugs using an N-in-1 (cassette) approach and relate these parameters to drug physicochemical properties and tissue thickness through quantitative structure permeability relationships (QSPRs). [...] Read more.
The purpose of this study was to determine corneal permeability and uptake in rabbit, porcine, and bovine corneas for twenty-five drugs using an N-in-1 (cassette) approach and relate these parameters to drug physicochemical properties and tissue thickness through quantitative structure permeability relationships (QSPRs). A twenty-five-drug cassette containing β-blockers, NSAIDs, and corticosteroids in solution at a micro-dose was exposed to the epithelial side of rabbit, porcine, or bovine corneas mounted in a diffusion chamber, and the corneal drug permeability and tissue uptake were monitored using an LC-MS/MS method. Data obtained were used to construct and evaluate over 46,000 quantitative structure–permeability (QSPR) models using multiple linear regression, and the best-fit models were cross-validated by Y-randomization. Drug permeability was generally higher in rabbit cornea and comparable between bovine and porcine corneas. Permeability differences between species could be explained in part by differences in corneal thickness. Corneal uptake between species correlated with a slope close to 1, indicating generally similar drug uptake per unit weight of tissue. A high correlation was observed between bovine, porcine, and rabbit corneas for permeability and between bovine and porcine corneas for uptake (R2 ≥ 0.94). MLR models indicated that drug characteristics such as lipophilicity (LogD), heteroatom ratio (HR), nitrogen ratio (NR), hydrogen bond acceptors (HBA), rotatable bonds (RB), index of refraction (IR), and tissue thickness (TT) are of great influence on drug permeability and uptake. When data for all species along with thickness as a parameter was used in MLR, the best fit equation for permeability was Log (% transport/cm2·s) = 0.441 LogD − 8.29 IR + 8.357 NR − 0.279 HBA − 3.833 TT + 10.432 (R2 = 0.826), and the best-fit equation for uptake was Log (%/g) = 0.387 LogD + 4.442 HR + 0.105 RB − 0.303 HBA − 2.235 TT + 1.422 (R2 = 0.750). Thus, it is feasible to explain corneal drug delivery in three species using a single equation. Full article
(This article belongs to the Special Issue Recent Advances in Long-Acting Drug Delivery and Formulations)
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17 pages, 13240 KiB  
Article
Corneal Edema in Inducible Slc4a11 Knockout Is Initiated by Mitochondrial Superoxide Induced Src Kinase Activation
by Diego G. Ogando, Edward T. Kim, Shimin Li and Joseph A. Bonanno
Cells 2023, 12(11), 1528; https://doi.org/10.3390/cells12111528 - 1 Jun 2023
Cited by 4 | Viewed by 2872
Abstract
Purpose: Inducible Slc4a11 KO leads to corneal edema by disruption of the pump and barrier functions of the corneal endothelium (CE). The loss of Slc4a11 NH3-activated mitochondrial uncoupling leads to mitochondrial membrane potential hyperpolarization-induced oxidative stress. The goal of this study [...] Read more.
Purpose: Inducible Slc4a11 KO leads to corneal edema by disruption of the pump and barrier functions of the corneal endothelium (CE). The loss of Slc4a11 NH3-activated mitochondrial uncoupling leads to mitochondrial membrane potential hyperpolarization-induced oxidative stress. The goal of this study was to investigate the link between oxidative stress and the failure of pump and barrier functions and to test different approaches to revert the process. Methods: Mice which were homozygous for Slc4a11 Flox and Estrogen receptor –Cre Recombinase fusion protein alleles at 8 weeks of age were fed Tamoxifen (Tm)-enriched chow (0.4 g/Kg) for 2 weeks, and controls were fed normal chow. During the initial 14 days, Slc4a11 expression, corneal thickness (CT), stromal [lactate], Na+-K+ ATPase activity, mitochondrial superoxide levels, expression of lactate transporters, and activity of key kinases were assessed. In addition, barrier function was assessed by fluorescein permeability, ZO-1 tight junction integrity, and cortical cytoskeleton F-actin morphology. Results: Tm induced a rapid decay in Slc4a11 expression that was 84% complete at 7 days and 96% complete at 14 days of treatment. Superoxide levels increased significantly by day 7; CT and fluorescein permeability by day 14. Tight junction ZO-1 distribution and the cortical cytoskeleton were disrupted at day 14, concomitant with decreased expression of Cldn1, yet with increased tyrosine phosphorylation. Stromal lactate increased by 60%, Na+-K+ ATPase activity decreased by 40%, and expression of lactate transporters MCT2 and MCT4 significantly decreased, but MCT1 was unchanged at 14 days. Src kinase was activated, but not Rock, PKCα, JNK, or P38Mapk. Mitochondrial antioxidant Visomitin (SkQ1, mitochondrial targeted antioxidant) and Src kinase inhibitor eCF506 significantly slowed the increase in CT, with concomitant decreased stromal lactate retention, improved barrier function, reduced Src activation and Cldn1 phosphorylation, and rescued MCT2 and MCT4 expression. Conclusions: Slc4a11 KO-induced CE oxidative stress triggered increased Src kinase activity that resulted in perturbation of the pump components and barrier function of the CE. Full article
(This article belongs to the Special Issue Cell Biology of the Cornea and Ocular Surface)
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