Bovine Corneal Research Articles

Characterization of Biocompatible Gellan Gum Fractions for Prolonged Retention in Ocular Drug Delivery Systems

ABSTRACTGellan gum (GG) emerges as a promising candidate for developing polymeric carriers with extended retention on the ocular surface, aiming to enhance the efficacy of topical ocular drug delivery systems. This study undertakes the purification of commercial GG through fractional dissolution and ultrasonic treatment, producing fractions characterized by 1H, 13C NMR, FTIR spectroscopy and thermogravimetric analysis. The intrinsic viscosity of GG samples was measured in a 0.025 M tetramethylammonium chloride solution and their molecular weights were calculated via the Mark‐Kuhn‐Houwink equation. Methodological choices regarding synthetic procedures, solvents and reagents were guided by considerations of biocompatibility, aligning with the end goal of drug delivery applications. The study further explores the mucoadhesive potential of GG fractions with varying molecular weights for ocular drug delivery, utilizing an in vitro flow‐through technique with fluorescent detection on freshly excised bovine corneal mucosa surfaces. The findings under‐score the viability of GG formulations in enhancing ocular drug retention and pave the way for future applications in topical ocular therapeutics.

P21 Advancing dermatological care: a comprehensive evaluation of the steroid-free GL-1 formulation

Abstract Introduction and aims The prolonged use of topical steroids introduces notable dermatological risks, including the onset of permanent stretch marks, bruising, discoloration and vascular abnormalities. This study presents an innovative strategy by formulating GL-1, a steroid-free treatment amalgamating seaweed bioactives, sesame oil and naturally occurring salts and minerals. The objective of this study was to address the limitations of conventional topical steroids and introduce pioneering solutions to dermatological care. Methods To assess the safety and efficacy of GL-1 (product 1), a comprehensive battery of in vitro tests was employed. The skin corrosion test (OECD 431) established the noncorrosive nature of GL-1, validating its safety on reconstructed human epidermis. The skin irritation test (OECD 439) demonstrated the nonirritating attributes of GL-1, aligning with the United Nations Globally Harmonized System of Classification and Labelling guidelines. Additionally, the bovine corneal opacity and permeability test (OECD 437) affirmed the noninducing nature of GL-1 in relation to eye irritation or serious eye damage. Results Preliminary outcomes from dermal clinical trials indicate promising Results for GL-1. In vitro experiments on HaCaT and human dermal fibroblasts, adult (HDFa) cell lines highlighted the noncytotoxicity of GL-1, contrasting with the ‘Cortopin’, which exhibited cytotoxicity. GL-1 exhibited a proliferative effect in HDFa cells, signifying its potential for regenerative applications. Furthermore, both GL-1 and ‘Cortopin’ displayed antioxidant activity in HaCaT cells, underscoring the additional merits of our formulation. Conclusions Our steroid-free formulation, GL-1, demonstrates exceptional safety and efficacy through a meticulous series of in vitro assessments and initial clinical trials. These findings position GL-1 as a promising candidate for diverse dermal applications, offering a secure alternative to traditional topical steroids. The potential impact of GL-1 transcends its therapeutic efficacy, emphasizing its robust safety profile validated through multiple in vitro evaluations.

Antihypertensive Potential of Japanese Quail (Couturnix Couturnix Japonica) Egg Yolk Oil (QEYO) in Sprague Dawley Rats.

Oils from animal sources have been used for centuries in the management of diseases. This research was conducted to screen the ex vivo and in vivo toxicity of quail egg yolk oil (QEYO) extracts and assess their effects on the management of hypertension in rats. QEYO was extracted using gentle heating (GH) and n-hexane (NHN). The extracts were subjected to toxicity testing using the hen's egg test on chorioallantoic membrane (HET-CAM) and bovine corneal histology test. Acute and sub-chronic toxicity (28 days) were evaluated in rats. Hypertension was induced in rats by administering 80 mg/kg of Nω-L-Arginine Methyl Ester (L-NAME) per day for 28 days. Treatments commenced on the 14th day; Nifedipine at 30 mg/kg and 1 mL of distilled water were administered as positive and negative controls. Blood pressure (BP), lipid profiles, and oxidative stress markers were quantified. No irritation was observed using the HET-CAM test in the egg treated with both extracts. Bovine corneal histology showed no lesions in all treated groups. No signs of toxicity were observed in either acute or sub-chronic toxicity studies. A significant reduction in blood pressure was observed in rats treated with the extracts (p < 0.05). Changes in total cholesterol (TC), triglycerides (TGs), low-density lipoproteins (LDLPs), and high-density lipoproteins (HDLPs) were not significant compared to the control (p > 0.05). Oxidative stress markers (SOD and CAT) increased significantly in the treated groups compared to the control, while the malondialdehyde levels decreased (p < 0.05). QEYO was safe in both ex vivo and in vivo studies and can be said to have the potential to lower blood pressure as well as cardio-protective effects in hypertensive rats. This research provides evidence based on which QEYO could be used safely as an adjuvant therapy in eye drops and cosmetics and can be considered an effective choice for preventing hypertension.

Phospholipid Free Nano-Vesicles of Brinzolamide Biopolymer Ocular Insert; Design, In vitro and In vivo Evaluation

The aim of this work to study the feasibility of using phospholipid free vesicles with positive charge inducer in a slowly dissolving polymer ocular insert to successfully control intraocular pressure (IOP) for an extended period. Brinzolamide (BRNZ) was chosen as a model drug and a full factorial design was assembled to investigate the drug loading effect, ratio of cholesterol to fatty moiety and the type of the fatty moiety used on the vesicle size and entrapment efficiency. Linear regression models were constructed, and optimization of the formulation compositions yielded two formulae with palmitic acid as a negatively charged vesicles and cetrimide positively charged vesicles. Both formulae were studied in term of permeation efficiency through bovine corneal membranes. Positively charged vesicles although it didn't achieve the highest flux and cumulative amount permeated per unit surface area in the experiment time course, it achieved the highest retention of drug inside the corneal tissue, so it was chosen to be incorporated in a slowly dissolving polymer ocular insert. The insert was evaluated in term content, physical evaluation, and release properties. In vivo evaluation of the casted ocular inserts was conducted in male albino rabbits against market eye drop product and IOP readings were collected for 48 hours. The positively charged sterosomes containing BRNZ and formulated in polymer ocular inserts achieved extended control of IOP of the test animals compared to the market product.

ECM-based bioadhesive hydrogel for sutureless repair of deep anterior corneal defects.

Corneal transplantation is the gold standard treatment for corneal-related blindness; however, this strategy faces challenges such as limited donor cornea, graft rejection, suture-related complications, and the need for specialized equipment and advanced surgical skills. Development of tissue adhesives for corneal regeneration is of great clinical value. However, currently available corneal tissue sealants pose challenges, such as lack of safety, biocompatibility, and desired mechanical properties. To meet these requirements simultaneously, a bovine stromal corneal extracellular matrix (dCor) was used to design a bioadhesive photocurable hydrogel based on gelatin methacrylate (GelMA) and polyethylene glycol diacrylate (PEGDA) hydrogels (dCor/Gel-PEG). Integration of dCor into the dual networks of GelMA and PEGDA (Gel-PEG) led to a bioadhesive hydrogel for curing corneal defects, which could be crosslinked by Irgacure 2959 within 5 min ultraviolet irradiation. The viability of corneal stromal stem cells (CSSCs) was improved on the dCor/Gel-PEG hydrogel in comparison to the Gel-PEG hydrogel. The gene expression profile supported the keratocyte differentiation of CSSCs seeded on dCor/Gel-PEG via increased KERA and ALDH, with inhibited myofibroblast transdifferentiation via decreased α-SMA due to the presence of dCor. Interestingly, the dCor/Gel-PEG hydrogel exhibited favorable mechanical performance in terms of elasticity and bioadherence to the host corneal stroma. Ex vivo and in vivo examinations proved the feasibility of this hydrogel for the sutureless reconstruction of deep anterior corneal defects with promising histopathological results.

Morfologia das células endoteliais corneanas bovinas obtidas com alizarina vermelha e microscopia óptica

Abstract The aim of this study was to determine the endothelial cell morphology in the different regions of healthy bovine corneal endothelium using optical microscopy. Twenty eyeballs from 10 male Brangus cattle, aged 24 months, were studied. The corneal endothelium was stained with the vital dye alizarin red and then examined with an optical microscope and photographed. Thirty endothelial cells from each corneal region were included in the analysis. Endothelial cell morphology was analysed in the central, superior, inferior, lateral and medial regions of the cornea. Comparisons between regions were performed using repeated measures analysis of variance (ANOVA). Differences were considered statistically significant at P &lt; 0.05. Normal endothelial cells were mainly hexagonal (83.7%), pentagonal (7.45%) and heptagonal (8.8%), with a minimal number of cells of other shapes present. No statistical differences were observed in the endothelial cell morphology when comparing different regions of the cornea. Regarding endothelial cell morphology, there were no differences between the corneal regions.

Morphology of bovine corneal endothelial cells obtained with alizarin red and optical microscopy

Resumo O objetivo deste estudo foi determinar a morfologia das células endoteliais nas diferentes regiões do endotélio da córnea bovina saudável por meio de microscopia óptica. Foram estudados 20 globos oculares de 10 bovinos machos da raça Brangus, com idade de 24 meses. O endotélio da córnea foi corado com o corante vital vermelho de alizarina e, em seguida, examinado no microscópio óptico e fotografado. Trinta células endoteliais de cada região da córnea foram incluídas na análise. A morfologia das células endoteliais foi analisada nas regiões central, superior, inferior, lateral e medial da córnea. As comparações entre as regiões foram realizadas usando medidas repetidas de análise de variância (ANOVA). As diferenças foram consideradas estatisticamente significativas em P &lt; 0,05. As células endoteliais normais eram principalmente hexagonais (83,7%), pentagonais (7,45%) e heptagonais (8,8%), com um número mínimo de células de outras formas presentes. Não foram observadas diferenças estatísticas na morfologia das células endoteliais quando comparadas as diferentes regiões da córnea. Em relação à morfologia das células endoteliais não houve diferenças entre as regiões da córnea estudadas.

Defined approaches to classify agrochemical formulations into EPA hazard categories developed using EpiOcularTM reconstructed human corneal epithelium and bovine corneal opacity and permeability assays

Many sectors have seen complete replacement of the in vivo rabbit eye test with reproducible and relevant in vitro and ex vivo methods to assess the eye corrosion/irritation potential of chemicals. However, the in vivo rabbit eye test remains the standard test used for agrochemical formulations in some countries. Therefore, two defined approaches (DAs) for assessing conventional agrochemical formulations were developed, using the EpiOcularTM Eye Irritation Test (EIT) [Organisation for Economic Co-operation and Development (OECD) test guideline (TG) 492] and the Bovine Corneal Opacity and Permeability (OECD TG 437; BCOP) test with histopathology. Presented here are the results from testing 29 agrochemical formulations, which were evaluated against the United States Environmental Protection Agency’s (EPA) pesticide classification system, and assessed using orthogonal validation, rather than direct concordance analysis with the historical in vivo rabbit eye data. Scientific confidence was established by evaluating the methods and testing results using an established framework that considers fitness for purpose, human biological relevance, technical characterisation, data integrity and transparency, and independent review. The in vitro and ex vivo methods used in the DAs were demonstrated to be as or more fit for purpose, reliable and relevant than the in vivo rabbit eye test. Overall, there is high scientific confidence in the use of these DAs for assessing the eye corrosion/irritation potential of agrochemical formulations.

Human cornea-derived extracellular matrix hydrogel for prevention of post-traumatic corneal scarring: A translational approach.

Corneal scarring and opacification are a significant cause of blindness affecting millions worldwide. The current standard of care for corneal blindness is corneal transplantation, which suffers from several drawbacks. One alternative approach that has shown promise is the use of xenogeneic corneal extracellular matrix (ECM), but its clinical applicability is challenging due to safety concerns. This study reports the innovative use of human cornea-derived ECM to prevent post-traumatic corneal scarring. About 30 - 40% of corneas donated to the eye banks do not meet the standards defined for clinical use and are generally discarded, although they are completely screened for their safety. In this study, human cornea-derived decellularized ECM hydrogel was prepared from the non-transplantation grade human cadaveric corneas obtained from an accredited eye-bank. The prepared hydrogel was screened for its efficacy against corneal opacification following an injury in an animal model. Our in vivo study revealed that, the control collagen-treated group developed corneal opacification, while the prophylactic application of human cornea-derived hydrogel effectively prevented corneal scarring and opacification. The human hydrogel-treated corneas were indistinguishable from healthy corneas and comparable to those treated with the xenogeneic bovine corneal hydrogel. We also demonstrated that the application of the hydrogel retained the biological milieu including cell behavior, protein components, optical properties, curvature, and nerve regeneration by remodeling the corneal wound after injury. The hydrogel application is also sutureless, resulting in faster corneal healing. We envision that this human cornea-derived ECM-based hydrogel has potential clinical application in preventing scarring from corneal wounding. STATEMENT OF SIGNIFICANCE: There are significant challenges surrounding corneal regeneration after injury due to extensive scarring. Although there is substantial research on corneal regeneration, much of it uses synthetic materials with chemical cross-linking methods or xenogeneic tissue-based material devices which have to undergo exhaustive safety analysis before clinical trials. Herein, we demonstrate the potential application of a human corneal extracellular matrix hydrogel without any additional materials for scarless corneal tissue regeneration, and a method to reduce the wasting of donated allogenic corneal tissue from eye banks. We found no difference in efficacy between the usage of human tissues compared to xenogeneic sources. This may help ease clinical translation and can be used topically without sutures as an outpatient procedure.

Pre-clinical safety of topically administered sunitinib-loaded lipid and polymeric nanocarriers targeting corneal neovascularization

Three different types of sunitinib-loaded (SUN-loaded) nanocarriers were compared, aiming at the topical treatment of corneal neovascularization (CNV): polymeric nanospheres (NS), liposomes (LIP), and solid lipid nanoparticles (SLN). Three out of eleven formulations prepared for an optimization study – the best SUN-loaded nanocarrier of each assessed type (NS, LIP, and SLN) – were selected, based on their size, polydispersity index (PdI), drug load (DL), and encapsulation efficiency (EE). These three optimal formulations were further characterized by nanoparticle tracking analysis (NTA), electron paramagnetic resonance (EPR) spectroscopy, and zeta potential. In vitro SUN release profiles were obtained for the optimal formulations, along with ex vivo corneal permeability/retention studies, and ocular tolerance assays, namely: the bovine corneal opacity and permeability (BCOP) assay, the HET-CAM test (hen’s egg test – chorioallantoic membrane), and hemolytic potential (HP) assay. None of the optimal formulations exhibited toxicity or potential for ocular irritation. SLN showed higher surface fluidity, drug release more suitable for topical ocular applications, besides greater SUN corneal retention. Our results suggest that SLN are the best CNV-targeting SUN-loaded nanocarriers for clinical translation when compared to their NS and LIP analogues.

Pickering emulsions stabilised with oligoglycine-functionalised nanodiamond as a model system for ocular drug delivery applications.

Oil-in-water emulsions, stabilised with conventional surfactants, are commonly used in eye drops for ocular drug delivery. However, the presence of surfactants can sometimes irritate tissues. Furthermore, conventional emulsions often have poor retention on ocular tissue. Pickering emulsions stabilised with nanoparticles have been gaining attention in recent years for a range of biomedical applications because of their biocompatibility. Here, Pickering emulsions were evaluated for the first time for the confinement of organic components for potential application in ocular drug delivery. For a model system, we used nanodiamond (ND) nanoparticles functionalised with covalently-bonded two-tail (2T) oligoglycine C10(NGly4)2 to make Pickering oil-in-water emulsions, which were stable over three months of storage under neutral pH. We proved the non-toxicity of ND-2T Pickering emulsions, comparable to buffer solution, via an ex vivo bovine corneal permeability and opacity test. The retention of the oil phase in the ND-2T stabilised emulsions on corneal tissue is significantly increased because of the mucoadhesive properties arising from the positively-charged terminal amino groups of 2T. Our formulated emulsions have a surface tension, pH and salt concentration comparable to that of tear fluid. The high retention of the ND-2T-stabilised emulsions on the corneal surface, in combination with their non-toxicity, gives them distinct advantages for ocular drug delivery. The principles of this model system could be applied in the future design of a range of formulations for drug delivery.

Specular microscopy of the corneal endothelial cells of bovines: an ex vivo study.

The endothelium is the most posterior layer of the cornea and is essential for maintaining corneal transparency. Due to variations in corneal endothelial parameters among different species, knowledge of the normal parameters for each species is crucial. To evaluate the corneal endothelium of bovines using contact specular microscopy. Twenty eyeballs from 10 male Brangus (Bos taurus) aged 24 months were evaluated. Contact specular microscopy was performed on the central corneal area. The analyzed parameters were endothelial cell density (ECD) and endothelial cell morphology. The ECD in the central area was 1,277 cells/mm2. Regarding the morphology, mainly cells with six (74.3%), five (14.7%) and seven sides (10%) were found. There were no significant differences in ECD and morphology between left and right eyes. Contact specular microscopy facilitated the analysis and measurement of corneal endothelial parameters in bovines. The data obtained will serve as a reference for the analysis of bovine corneal endothelium.

A mathematical model of wound healing in bovine corneal endothelium

We developed a mathematical model to describe healing processes in bovine corneal endothelial (BCE) cells in culture, triggered by mechanical wounds with parallel edges. Previous findings from our laboratory show that, in these cases, BCE monolayers exhibit an approximately constant healing velocity. Also, that caspase-dependent apoptosis occurs, with the fraction of apoptotic cells increasing with the distance traveled by the healing edge. In addition, in this study we report the novel findings that, for wound scratch assays performed preserving the basal extracellular matrix: i) the healing cells increase their en face surface area in a characteristic fashion, and ii) the average length of the segments of the cell columns actively participating in the healing process increases linearly with time. These latter observations preclude the utilization of standard traveling wave formalisms to model wound healing in BCE cells. Instead, we developed and studied a simple phenomenological model based on a plausible formula for the spreading dynamics of the individual healing cells, that incorporates original evidence about the process in BCE cells. The model can be simulated to: i) obtain an approximately constant healing velocity; ii) reproduce the profile of the healing cell areas, and iii) obtain approximately linear time dependences of the mean cell area and average length of the front active segments per column. In view of its accuracy to account for the experimental observations, the model can also be acceptably employed to quantify the appearance of apoptotic cells during BCE wound healing. The strategy utilized here could offer a novel formal framework to represent modifications undergone by some epithelial cell lines during wound healing.

Cell derived matrices from bovine corneal endothelial cells as a model to study cellular dysfunction

PurposeFuchs endothelial corneal dystrophy (FECD) is a progressive corneal disease that impacts the structure and stiffness of the Descemet's membrane (DM), the substratum for corneal endothelial cells (CECs). These structural alterations of the DM could contribute to the loss of the CECs resulting in corneal edema and blindness. Oxidative stress and transforming growth factor-β (TGF-β) pathways have been implicated in endothelial cell loss and endothelial to mesenchymal transition of CECs in FECD. Ascorbic acid (AA) is found at high concentrations in FECD and its impact on CEC survival has been investigated. However, how TGF-β and AA effect the composition and rigidity of the CEC's matrix remains unknown. MethodsIn this study, we investigated the effect of AA, TGF-β1 and TGF-β3 on the deposition, ultrastructure, stiffness, and composition of the extracellular matrix (ECM) secreted by primary bovine corneal endothelial cells (BCECs). ResultsImmunofluorescence and electron microscopy post-decellularization demonstrated a robust deposition and distinct structure of ECM in response to treatments. AFM measurements showed that the modulus of the matrix in BCECs treated with TGF-β1 and TGF-β3 was significantly lower than the controls. There was no difference in the stiffness of the matrix between the AA-treated cell and controls. Gene Ontology analysis of the proteomics results revealed that AA modulates the oxidative stress pathway in the matrix while TGF-β induces the expression of matrix proteins collagen IV, laminin, and lysyl oxidase homolog 1. ConclusionsMolecular pathways identified in this study demonstrate the differential role of soluble factors in the pathogenesis of FECD.

Comparative study of two re-embedding methods on the ultrastructure of corneal tissue

PurposeTo expand the routine of pathological diagnostics of surgical keratoplasty specimens via transmission electron microscopy. The target was to identify the best re-embedding method for optimal structural preservation of formalin fixed paraffin embedded (FFPE) corneal tissue re-embedded into resin for ultrastructural analysis. Basic proceduresBovine FFPE corneal tissue was re-embedded into resin with either a rapid osmium-free four-hour-method or a four-day-routine-method known from nephropathology, compared with primary resin embedded bovine corneal tissue. The analysis involved the ultrastructure of cytoplasm, the intercellular interfaces of superficial epithelial cells, deepest basal epithelial cells and corneal endothelial cells, cell matrix interfaces, Bowman layer, corneal stroma, its microfibril bundles and Descemet membrane. Main findingsThe main observation was the equally reduced preservation status of re-embedded FFPE corneal tissue independent of the used re-embedding method. This extends to the intercellular contacts of superficial epithelial cells and the apical tight junctions of corneal endothelial cells. Hemidesmosomal cell matrix contacts showed less demarcation in re-embedded specimens. Cell matrix interfaces of Bowman layer and Descemet membrane were more clearly bordered in primary resin embedded than re-embedded tissue. In contrast, gap junctions in re-embedded tissue were detected in deepest basal epithelial cells and corneal endothelial cells with comparable preservation to primary resin embedding. Bowman layer, corneal stromal extracellular matrix, its microfibril bundles and Descemet membrane showed equal ultrastructural preservation in all evaluated methods. Principal conclusionCorneal tissue can be successfully analysed with transmission electron microscopy after a rapid osmium-free four hour re-embedding procedure from FFPE material. A comparable morphology with primary resin embedded material can be obtained for gap junctions of deepest basal epithelial cells and corneal endothelial cells, further for Bowman layer, corneal stromal extracellular matrix, its microfibril bundles and Descemet membrane.

A REVIEW ON HOW TO CHARACTERIZE AND EVALUATE THE OPHTHALMIC IN SITU GEL PREPARATIONS

In situ gelling systems are becoming one of the most popular and well-known, with many potential benefits from delivery systems, such as ease of use and ease of manufacture, improve adherence and patient comfort by minimizing the frequency of drug administration. In this review, we will describe the characterization and evaluation of the ophthalmic in situ gel preparation. Among them are physical evaluation (appearance and clarity, pH, isotonicity, gelation temperature, gelling capacity, viscosity, and stability), chemical evaluation (determining drug content, drug release), microbiological evaluation (sterility, ocular irritability, ocular tolerability, antimicrobial activity, hemolysis activity, bovine corneal opacity and permeability (BCOP) test, preservative efficacy test (PET), microtetrazolium (MTT) reduction cytotoxicity test), and in vivo evaluation such as pharmacokinetic and pharmacodynamic evaluation. Characterizing the chemical, physical, microbiological, and miscellaneous properties of ophthalmic in situ gel formulations can meet the ideal requirements and help determine the best formulation of ophthalmic in situ gel to achieve higher bioavailability values, longer contact times, minimize side effects, not causing irritation or liquid tear production, and providing a maximum therapeutic effect. In situ gels offer the primary requirement of a successful controlled release product that is increasing patient compliance.

A lipid nanoparticle platform for mRNA delivery through repurposing of cationic amphiphilic drugs.

Since the recent clinical approval of siRNA-based drugs and COVID-19 mRNA vaccines, the potential of RNA therapeutics for patient healthcare has become widely accepted. Lipid nanoparticles (LNPs) are currently the most advanced nanocarriers for RNA packaging and delivery. Nevertheless, the intracellular delivery efficiency of state-of-the-art LNPs remains relatively low and safety and immunogenicity concerns with synthetic lipid components persist, altogether rationalizing the exploration of alternative LNP compositions. In addition, there is an interest in exploiting LNP technology for simultaneous encapsulation of small molecule drugs and RNA in a single nanocarrier. Here, we describe how well-known tricyclic cationic amphiphilic drugs (CADs) can be repurposed as both structural and functional components of lipid-based NPs for mRNA formulation, further referred to as CADosomes. We demonstrate that selected CADs, such as tricyclic antidepressants and antihistamines, self-assemble with the widely-used helper lipid DOPE to form cationic lipid vesicles for subsequent mRNA complexation and delivery, without the need for prior lipophilic derivatization. Selected CADosomes enabled efficient mRNA delivery in various in vitro cell models, including easy-to-transfect cancer cells (e.g. human cervical carcinoma HeLa cell line) as well as hard-to-transfect primary cells (e.g. primary bovine corneal epithelial cells), outperforming commercially available cationic liposomes and state-of-the-art LNPs. In addition, using the antidepressant nortriptyline as a model compound, we show that CADs can maintain their pharmacological activity upon CADosome incorporation. Furthermore, in vivo proof-of-concept was obtained, demonstrating CADosome-mediated mRNA delivery in the corneal epithelial cells of rabbit eyes, which could pave the way for future applications in ophthalmology. Based on our results, the co-formulation of CADs, helper lipids and mRNA into lipid-based nanocarriers is proposed as a versatile and straightforward approach for the rational development of drug combination therapies.

Roles of early events in the modifications undergone by bovine corneal endothelial cells during wound healing.

A mechanical injury in bovine corneal endothelial (BCE) cells in culture induces: (1) a fast calcium wave (FCW); (2) slow increases in cytosolic sodium and calcium, critical for the healing process, and (3) a rise in the apoptotic rate with respect to quiescent cells. In order to investigate the nature of the stimuli that determine the ionic changes and apoptotic response, we performed here studies on a non-injury model of tissue restitution in BCE monolayers. For this, we employed cell cultures grown to confluence in the presence of a Parafilm strip. We observed that, previously to strip removal, most of the border cells had already developed the slow ionic modifications, while in the scratch wounds these changes gradually occur after several hours of healing. This finding suggests that, in BCE cells, the presence of a free edge is sufficient to trigger ionic modifications necessary for wound healing and to elicit an augmented apoptotic response. The apoptotic index of the migrating cells in the Parafilm model (PF) was determined to be approximately two-fold the one of scratch wounds, a result that, in agreement with our previous observations, we attributed to the absence of the FCW in the PF experiments. The findings of this work further contribute to the understanding of epithelial wound healing, a crucial adaptive, and homeostatic response.

In Silico Design and In Vitro Evaluation of Some Novel AMPs Derived From Human LL-37 as Potential Antimicrobial Agents for Keratitis.

The human body produces two classes of antimicrobial peptides (AMPs), namely defensins and cathelicidins. In this study, a novel decapeptide (Catoid) and its dimer (Dicatoid) based on human cathelicidin (LL-37) have been designed by bioinformatics tools to be used in the treatment of bacterial keratitis. After the selection and synthesis of peptide sequences, their antimicrobial activities against the standard and resistant strains of Pseudomonas aeruginosa and Staphylococcus aureus were evaluated. This test was performed with LL-37, gentamicin, ciprofloxacin, amikacin, and penicillin for a more accurate comparison. Furthermore, the cytotoxicity levels of the specified compounds on fibroblast cells and bovine corneal endothelial cells were investigated. The results demonstrated that the designed peptides had a superior antimicrobial activity on P. aeruginosa, compared to LL-37; however, Catoid had a better effect on the S. aureus strain. Additionally, a significant achievement is the very low toxicity level of Catoid and Dicatoid on the human skin fibroblast cell line and bovine corneal endothelial cells, compared to that of LL-37 as the initial design model.

Development of the stability-indicating method, structural elucidation of new photodegradation products from terconazole by LC-MS TOF, and in vitro toxicity

Terconazole (TCZ) was the first triazole antifungal drug launched in the market and has been used in the treatment of vulvovaginal candidiasis. It is also indicated to treat dermatophytosis and fungal ocular infections. However, some of the degradation products from triazole drugs have been reported to be toxic, justifying the need of further investigations about the stability of TCZ. identification of its degradation products and evaluation of their toxicity considering the new possibilities of therapeutic indications. Therefore, in this work a systematic investigation regarding photostability of TCZ was conducted. The active pharmaceutical ingredient (API) and its methanolic solution (100 µg mL−1) were kept into a photostability chamber under a UV light (200 Wh/m2; 1.2 × 106 lux/h) during 5 days and 90 min, respectively. A high-efficiency liquid chromatography method was developed for separation and identification of TCZ and its degradation products. The solid-state API remained stable throughout the test, whereas an extensive degradation was observed when in solution. In this case, four degradation products not yet reported in the literature were identified and characterized by electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS). Two degradation products presented m/z of 498 and the other two of 496 and 464, respectively. The results suggest that the degradation follows a first-order kinetic and involves the loss of chlorine atoms from the 2,4-dichlrophenyl moiety. Finally, TCZ submitted to the same stress condition as the API solution, increased significantly the opacity during the bovine corneal opacity and permeability test method (BCOP) indicating a potential to cause ocular toxicity. Further studies using the pure photolysis degradation products of TCZ characterized in this work are still necessary to confirm this find.