TNF-α Suppression Attenuates Limbal Stem Cell Damage in Ocular Injury.

Purpose: Ocular chemical injuries often cause uveal inflammation, upregulation of TNF-α at the limbus, and subsequent limbal stem cell (LSC) damage. In this study, we investigate the protective role of TNF-α suppression in LSC survival.

Methods: Corneal alkali injuries were performed using NaOH as previously described by our group.

An in vitro 3-dimensional Collagen-based Corneal Construct with Innervation Using Human Corneal Cell Lines.

Purpose: To develop a 3-dimensional corneal construct suitable for in vitro studies of disease conditions and therapies.

Design: In vitro human corneal constructs were created using chemically crosslinked collagen and chondroitin sulfate extracellular matrix and seeded with 3 human corneal cell types (epithelial, stromal, and endothelial) together with neural cells. The neural cells were derived from hybrid neuroblastoma cells and the other cells used from immortalized human corneal cell lines.

Opposing Roles of Blood-Borne Monocytes and Tissue-Resident Macrophages in Limbal Stem Cell Damage after Ocular Injury.

Limbal stem cell (LSC) deficiency is a frequent and severe complication after chemical injury to the eye. Previous studies have assumed this is mediated directly by the caustic agent. Here we show that LSC damage occurs through immune cell mediators, even without direct injury to LSCs.

Rational design of peptide-based implants for corneal bioengineering.

Regeneration of damaged cornea can save vision for millions of patients. Most of these patients are waiting for transplantation of a donor cornea or suitable substitute to restore vision. Although donor cornea transplantation is the most clinically accepted treatment, shortage of donor cornea results in almost 69 out of every 70 patients untreated with the waiting list for transplantation drastically increasing every year according to a prepandemic estimation.

Characterization of Octa-aminopropyl polyhedral oligomeric silsesquioxanes (OA-POSS) nanoparticles and their effect on sweet basil (Ocimum basilicum L.) response to salinity stress.

Salt stress is of the most detrimental abiotic stress factors on either crop or non-crop species. Of the strategies employed to boost the performance of the plants against harmful impacts of salt stress; application of novel nano-engineered particles have recently gained great attention as a promising tool. Octa-aminopropyl polyhedral oligomeric silsesquioxanes nanoparticles (OA-POSS NPs) were synthesized and then a foliar-application of OA-POSS NPs were carried out on sweet basil plants subjected to the salt stress.

Electron-Beam Irradiated Recombinant Human Collagen-Phosphorylcholine Corneal Implants Retain Pro-Regeneration Capacity.

Sterilization of biodegradable, collagen-based implants is challenging as irradiation sterilization methods can alter their mechanical properties. Electron beam (EB) irradiation is a terminal sterilization method that has been used for biologically-derived implants. Here, recombinant human collagen type III-phosphorylcholine (RHCIII-MPC) hydrogels were irradiated with EB doses of 17, 19, or 21 kGy and their subsequent biocompatibility and ability to promote regeneration in rabbit corneas was evaluated.

Crosslinker-free collagen gelation for corneal regeneration.

Development of an artificial cornea can potentially fulfil the demand of donor corneas for transplantation as the number of donors is far less than needed to treat corneal blindness. Collagen-based artificial corneas stand out as a regenerative option, having promising clinical outcomes. Collagen crosslinked with chemical crosslinkers which modify the parent functional groups of collagen.

Antiviral Polymers: A Review.

Polymers, due to their high molecular weight, tunable architecture, functionality, and buffering effect for endosomal escape, possess unique properties as a carrier or prophylactic agent in preventing pandemic outbreak of new viruses. Polymers are used as a carrier to reduce the minimum required dose, bioavailability, and therapeutic effectiveness of antiviral agents. Polymers are also used as multifunctional nanomaterials to, directly or indirectly, inhibit viral infections.

Graphene-Lined Porous Gelatin Glycidyl Methacrylate Hydrogels: Implications for Tissue Engineering.

Despite rigorous research, inferior mechanical properties and structural homogeneity are the main challenges constraining hydrogel's suturability to host tissue and limiting its clinical applications. To tackle those, we developed a reverse solvent interface trapping method, in which organized, graphene-coated microspherical cavities were introduced into a hydrogel to create heterogeneity and make it suturable. To generate those cavities, (i) graphite exfoliates to graphene sheets, which spread at the water/ heptane interfaces of the microemulsion, (ii) heptane fills the microspheres coated by graphene, and (iii) a cross-linkable hydrogel dissolved in water fills the voids.

Photo-cross-linked Gelatin Glycidyl Methacrylate/N-Vinylpyrrolidone Copolymeric Hydrogel with Tunable Mechanical Properties for Ocular Tissue Engineering Applications.

Corneal transplantation is currently the primary treatment for corneal blindness. However, severe global scarcity of donor corneas is driving the scientific community to find novel solutions. One potential solution is to replace the damaged tissue with a biocompatible artificial cornea.

Systematic optimization of visible light-induced crosslinking conditions of gelatin methacryloyl (GelMA).

Gelatin methacryloyl (GelMA) is one of the most widely used photo-crosslinkable biopolymers in tissue engineering. In in presence of an appropriate photoinitiator, the light activation triggers the crosslinking process, which provides shape fidelity and stability at physiological temperature. Although ultraviolet (UV) has been extensively explored for photo-crosslinking, its application has been linked to numerous biosafety concerns, originated from UV phototoxicity.

Critical media attributes in E-beam sterilization of corneal tissue.

When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea.

Optimization of Collagen Chemical Crosslinking to Restore Biocompatibility of Tissue-Engineered Scaffolds.

Collagen scaffolds, one of the most used biomaterials in corneal tissue engineering, are frequently crosslinked to improve mechanical properties, enzyme tolerance, and thermal stability. Crosslinkers such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) are compatible with tissues but provide low crosslinking density and reduced mechanical properties. Conversely, crosslinkers such as glutaraldehyde (GTA) can generate mechanically more robust scaffolds; however, they can also induce greater toxicity.

Chemical Constituent, Antimicrobial Activity, and Synergistic Effect of the Stem, Leaf, and Flower Essential Oil of the Artemisia fragrans Willd. from Khoy.

Artemisia fragrans is commonly used as a folk medicine as antispasmodic, anti-pyretic, anti-inflammatory, and abortifacient agents. The villagers use its pungent odor to repel rodents, mites, and pests, as well as its essential oil and smoke after burning to treat lung infections after uprooting the plant. Herein, we extracted the essential oils (EOs) of different parts of the plant and analyzed their chemical compositions and antibacterial activities.

Innate Immune Invisible Ultrasmall Gold Nanoparticles-Framework for Synthesis and Evaluation.

Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value.

Tuning gelatin-based hydrogel towards bioadhesive ocular tissue engineering applications.

Gelatin based adhesives have been used in the last decades in different biomedical applications due to the excellent biocompatibility, easy processability, transparency, non-toxicity, and reasonable mechanical properties to mimic the extracellular matrix (ECM). Gelatin adhesives can be easily tuned to gain different viscoelastic and mechanical properties that facilitate its ocular application. We herein grafted glycidyl methacrylate on the gelatin backbone with a simple chemical modification of the precursor, utilizing epoxide ring-opening reactions and visible light-crosslinking.

Toward electron-beam sterilization of a pre-assembled Boston keratoprosthesis.

Purpose: To evaluate the effects of electron-beam (E-beam) irradiation on the human cornea and the potential for E-beam sterilization of Boston keratoprosthesis (BK) devices when pre-assembled with a donor cornea prior to sterilization.

Methods: Human donor corneas and corneas pre-assembled in BK devices were immersed in recombinant human serum albumin (rHSA) media and E-beam irradiated at 25 kGy. Mechanical (tensile strength and modulus, and compression modulus), chemical, optical, structural, and degradation properties of the corneal tissue after irradiation and after 6 months of preservation were evaluated.

Electron Beam Sterilization of Poly(Methyl Methacrylate)-Physicochemical and Biological Aspects.

Electron beam (E-beam) irradiation is an attractive and efficient method for sterilizing clinically implantable medical devices made of natural and/or synthetic materials such as poly(methyl methacrylate) (PMMA). As ionizing irradiation can affect the physicochemical properties of PMMA, understanding the consequences of E-beam sterilization on the intrinsic properties of PMMA is vital for clinical implementation. A detailed assessment of the chemical, optical, mechanical, morphological, and biological properties of medical-grade PMMA after E-beam sterilization at 25 and 50 kiloGray (kGy) is reported.

Microporous Drug Delivery System for Sustained Anti-VEGF Delivery to the Eye.

Purpose: To describe a novel microporous drug delivery system (DDS) for sustained anti- vascular endothelial growth factor (VEGF) delivery to the eye and to evaluate its efficacy in a corneal injury model.

Methods: A macro-porous DDS (1.5 × 1.

Potential small-molecule drugs as available weapons to fight novel coronavirus (2019-nCoV): A review.

Since the new coronavirus known as 2019-nCoV (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) has widely spread in Wuhan, China, with severe pneumonia, scientists and physicians have made remarkable efforts to use various options such as monoclonal antibodies, peptides, vaccines, small-molecule drugs and interferon therapies to control, prevent or treatment infections of 2019-nCoV. However, no vaccine or drug has yet been confirmed to completely treat 2019-nCoV. In this review, we focus on the use of potential available small-molecule drug candidates for treating infections caused by 2019-nCoV.

Characterization of non-linear mechanical behavior of the cornea.

The objective of this study was to evaluate which hyperelastic model could best describe the non-linear mechanical behavior of the cornea, in order to characterize the capability of the non-linear model parameters to discriminate structural changes in a damaged cornea. Porcine corneas were used, establishing two different groups: control (non-treated) and NaOH-treated (damaged) corneas (n = 8). NaOH causes a chemical burn to the corneal tissue, simulating a disease associated to structural damage of the stromal layer.

Achillea filipendulina Lam.: Chemical Constituents and Antimicrobial Activities of Essential Oil of Stem, Leaf, and Flower.

In this study, we extracted the essential oils of the stem, leaf, and flower of Achillea filipendulina, analyzed them, and studied their antibacterial properties. Of 16, 53, and 35 compounds identified in the stem, leaf, and flowers, respectively, only five are present in all three segments of the plant. The essential oil of the stem was mainly composed of neryl acetate, spathulenol, carvacrol, santolina alcohol, and trans-caryophyllene oxide.

Chemical Composition and Antimicrobial Activity of Achillea tenuifolia Lam. Essential Oil at Different Phenological Stages from Khoy.

Achillea species and in particular Achillea tenuifolia Lam. is generally used as a food flavor and traditional remedies, especially in the initial developmental stage for medical conditions in the Mediterranean part of Iran. In this report, we extracted the essential oil from the aerial parts of A.

Glaucoma After Corneal Trauma or Surgery-A Rapid, Inflammatory, IOP-Independent Pathway.

Purpose: To review clinical aspects and cellular and molecular steps in the development of long-term glaucoma after corneal surgery or acute trauma-especially the pivotal role of tumor necrosis factor alpha (TNF-α), the rapidity of the secondary damage to the retinal ganglion cells, and the clinical promise of early antiinflammatory intervention.

Methods: A series of laboratory studies on post-injury and post-surgery glaucoma have been compared to clinical outcome studies on the subject, focusing particularly on the vulnerability of the retinal ganglion cells. Alkali burn to the cornea of mice and rabbits served as the main experimental model.