Cellular toxicity profile of a new ophthalmic sponge.

Introduction: Ophthalmic sponges are used for cleaning the eye surface and absorbing fluids during ophthalmic procedures. This study compared the biological safety and stability of a new ophthalmic sponge, Occucell® (OccuTech Inc, Seongnam, Korea), on the human conjunctival epithelial cells with those of preexisting products to evaluate its clinical application.Materials and Methods: The cytotoxicity of four products, Occucell, a new product, Ultracell®, Eyetec-1, and Eyetec-2, on conjunctival epithelial cells, was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) analysis. Additionally, human conjunctival epithelial cells were stained with a Live & Dead marker and observed using a fluorescence microscope. To evaluate the effect of the ophthalmic sponges on the secretion of IL-1ß and TNF-α, cultured conjunctival epithelial cells were treated with 0.5% DMSO eluates of the ophthalmic sponges, and IL-1ß and TNF-α mRNA levels were estimated using real-time polymerase chain reaction assays.Results: Cells treated with Occucell showed comparable viability to those treated with other preexisting products. Conjunctival epithelial cells showed more than 90% viability when treated with the ophthalmic sponge extracts, as determined by the MTT assay. No significant differences in the number of live & dead cells were observed between the control and treatment groups. Cells treated with all four ophthalmic sponge eluates showed similar IL-1ß and TNF-α mRNA levels.Discussion: Occucell, an eye sponge used during ophthalmic surgery in clinical practice, did not affect the viability of conjunctival epithelial cells, and more than 90% of the cells were viable after the treatment. Further, Occucell showed similar effects on IL-1ß and TNF-α secretion as that of other ophthalmic sponges used in the clinic. This suggested that Occucell is a safe product comparable to the preexisting products.

Nanophotosensitizers Composed of Phenyl Boronic Acid Pinacol Ester-Conjugated Chitosan Oligosaccharide via Thioketal Linker for Reactive Oxygen Species-Sensitive Delivery of Chlorin e6 against Oral Cancer Cells.

Chlorin E6 (Ce6)-incorporated nanophotosensitizers were fabricated for application in photodynamic therapy (PDT) of oral cancer cells. For this purpose, chitosan oligosaccharide (COS) was conjugated with hydrophobic and reactive oxygen species (ROS)-sensitive moieties, such as phenyl boronic acid pinacol ester (PBAP) via a thioketal linker (COSthPBAP). ThdCOOH was conjugated with PBAP to produce ThdCOOH-PBAP conjugates and then attached to amine groups of COS to produce a COSthPBAP copolymer. Ce6-incorporated nanophotosensitizers using the COSthPBAP copolymer were fabricated through the nanoprecipitation and dialysis methods. The Ce6-incorporated COSthPBAP nanophotosensitizers had a small diameter of less than 200 nm with a mono-modal distribution pattern. However, it became a multimodal and/or irregular distribution pattern when H2O2 was added. In a morphological observation using TEM, the nanophotosensitizers were disintegrated by the addition of H2O2, indicating that the COSthPBAP nanophotosensitizers had ROS sensitivity. In addition, the Ce6 release rate from the COSthPBAP nanophotosensitizers accelerated in the presence of H2O2. The SO generation was also higher in the nanophotosensitizers than in the free Ce6. Furthermore, the COSthPBAP nanophotosensitizers showed a higher intracellular Ce6 uptake ratio and ROS generation in all types of oral cancer cells. They efficiently inhibited the viability of oral cancer cells under light irradiation, but they did not significantly affect the viability of either normal cells or cancer cells in the absence of light irradiation. The COSthPBAP nanophotosensitizers showed a tumor-specific delivery capacity and fluorescence imaging of KB tumors in an in vivo animal tumor imaging study. We suggest that COSthPBAP nanophotosensitizers are promising candidates for the imaging and treatment of oral cancers.

Reactive Oxygen Species and Folate Receptor-Targeted Nanophotosensitizers Composed of Folic Acid-Conjugated and Poly(ethylene glycol)-Chlorin e6 Tetramer Having Diselenide Linkages for Targeted Photodynamic Treatment of Cancer Cells.

Folic acid-conjugated nanophotosensitizers composed of folic acid (FA), poly(ethylene glycol) (PEG) and chlorin e6 (Ce6) tetramer were synthesized using diselenide linkages for reactive oxygen species (ROS)- and folate receptor-specific delivery of photosensitizers. Ce6 was conjugated with 3-[3-(2-carboxyethoxy)-2,2-bis(2-carboxyethoxymethyl)propoxy]propanoic acid (tetra acid, or TA) to make Ce6 tetramer via selenocystamine linkages (TA-sese-Ce6 conjugates). In the carboxylic acid end group of the TA-sese-Ce6 conjugates, FA-PEG was attached again using selenocystamine linkages to make FA-PEG/TA-sese-Ce6 conjugates (abbreviated as FAPEGtaCe6 conjugates). Nanophotosensitizers were fabricated by a dialysis procedure. In the morphological observations, they showed spherical shapes with small diameters of less than 200 nm. Stability of the aqueous FAPEGtaCe6 nanophotosensitizer solution was maintained (i.e., their particle sizes were not significantly changed until 7 days later). When H2O2 was added to the nanophotosensitizer solution, the particle size distribution was changed from a monomodal pattern to a multimodal pattern. In addition, the fluorescence intensity and Ce6 release rate from the nanophotosensitizers were also increased by the addition of H2O2. These results indicated that the nanophotosensitizers had ROS-sensitive properties. In an in vitro cell culture study, an FAPEGtaCe6 nanophotosensitizer treatment against cancer cells increased the Ce6 uptake ratio, ROS generation and light-irradiated cytotoxicity (phototoxicity) compared with Ce6 alone against various cancer cells. When the folic acid was pretreated to block the folate receptors of the Y79 cells and KB cells (folate receptor-overexpressing cells), the intracellular Ce6 uptake, ROS generation and thereby phototoxicity were decreased, while the MCF-7 cells did not significantly respond to blocking of the folate receptors. These results indicated that they could be delivered by a folate receptor-mediated pathway. Furthermore, an in vivo pulmonary metastasis model using Y79 cells showed folate receptor-specific delivery of FAPEGtaCe6 nanophotosensitizers. When folic acid was pre-administered, the fluorescence intensity of the lungs was significantly decreased, indicating that the FAPEGtaCe6 nanophotosensitizers had folate receptor specificity in vitro and in vivo. We suggest that FAPEGtaCe6 nanophotosensitizers are promising candidates for a targeted photodynamic therapy (PDT) approach against cancer cells.

Salt Heat Treatment and Passivation to Improve the Corrosion Resistance of Nitinol (Ni-Ti).

Corrosion of nitinol (NiTi) is a major factor in the failure of implantable materials. Recently, as the importance of corrosion of metals has increased, testing according to international guidelines is essential. The purpose of this study was to evaluate the corrosion resistance of NiTi wire through heat treatment and passivation process. In this study, NiTi wire used two commercially available products and a self-manufactured stent. Experimental consideration was carried out according to ASTM standards. Heat treatment was carried out in an air or a salt furnace, and the corrosion was measured after additional process, such as passivation and scratch tests. As a result, the metal potential was rapidly decreased in the air furnace group. On the other hand, the potential of wires was dramatically increased in the salt furnace group compared to the air furnace group. The dislocation decreased below the acceptance criteria (>600 mV) within 60 s of heat treatment time in the air furnace. Moreover, the potential was dramatically improved, even after only 20 min of passivation treatment (1076 mV, 442% compared to the non-passivated group), and it continued to rise until 180 min. This phenomenon was similarly observed in the group of self-manufactured stents. The potential slightly decreased by the scratch process (93.1%) was significantly reduced by the air furnace process (315 mV, 24.4% of the nontreated group). In the passivated group of the air furnace sample with reduced potential, the potential was restored to the level before the air furnace (scratch stage) (1032 mV). In conclusion, the heat treatment is preferably carried out in a salt furnace rather than an air furnace, and the passivation process can be an advantageous tool to improve corrosion resistance by suppressing the oxidation process.

Dormant tie reactivation as an affiliative coping response to stressors during the COVID-19 crisis.

This study takes an affiliative coping theory perspective to examine whether working adults reactivated dormant ties with individuals they had not contacted for at least 3 years to cope with stressors experienced due to the COVID-19 pandemic. Stressors originating in the workplace (job insecurity and remote work) and in the family (stressful familial social ties) were examined in a sample of 232 working adults in the southeastern United States. Individuals were more likely to reactivate their dormant ties when their job was insecure, and the magnitude of the reactivations was greater among individuals experiencing stressful social ties with family members than those not experiencing those stressors. We also found that there was a significant interaction between remote work and having a stressful tie within the household in dormant tie reactivation. Although previous theory has focused mostly on the benefits of frequent, active social relationships for coping, our results suggest that reactivating dormant ties might be a coping mechanism as well. Our study also suggests that workplace dormant tie research should broaden its focus beyond exchanged instrumental support to consider emotional support that might be transferred during reactivation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Addition of MgO nanoparticles and plasma surface treatment of three-dimensional printed polycaprolactone/hydroxyapatite scaffolds for improving bone regeneration.

Magnesium (Mg) plays an important role in the body in mediating cell-extracellular matrix interactions and controlling bone apatite structure and density. Hydroxyapatite (HAp) has been used for osteoconductive bone replacement because of its good compressive strength and biocompatibility. The object of this study is to investigate the effects of adding Magnesium oxide (MgO) nanoparticles to polycaprolactone (PCL)/HAp composites and treating PCL/HAp/MgO scaffolds with oxygen and nitrogen plasma. The 3D PCL/HAp/MgO scaffolds were fabricated using a 3D bioextruder. PCL was mixed with 1-15wt% of MgO and HAp. The scaffolds were treated with oxygen and nitrogen plasma under anisotropic etching conditions to improve the bioactivity. The plasma-treated surfaces were analyzed by X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. In addition, the proliferation and differentiation of pre-osteoblast (MC3T3-E1) cells were examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and alkaline phosphatase activity. Cell mineralization within the produced scaffolds was analyzed by the quantification of alizarin stainings. The addition of MgO/HAp nanoparticles and plasma treatment enhanced the adhesion, proliferation, and differentiation of MC3T3-E1 cells in the PCL scaffolds. Hence, changes in physical surface morphology and surface chemical properties of the 3D scaffold by plasma treatment can affect the behavior of MC3T3-E1 cells.

Using the Endoscopic Transconjunctival and Transcaruncular Approach to Repair Combined Orbital Floor and Medial Wall Blowout Fractures.

PURPOSE: To demonstrate the effectiveness of the endoscopic transcaruncular and transconjunctival approach in the repair of combined medial and inferior orbital wall fractures. METHODS: A retrospective chart review was conducted on 160 patients with combined medial and inferior orbital wall fractures. All patients underwent surgery via an endoscopic transcaruncular and transconjunctival approach without lateral canthotomy, performed by a single surgeon. Porous polyethylene sheets (1.0 mm in thickness) were implanted to cover the orbital defects. The minimal postoperative follow-up period was 6 months. The authors evaluated enophthalmos, diplopia, and ocular motility pre and postoperatively and report surgical complications. RESULTS: A total of 160 patients were included, comprising 121 men and 39 women. The mean patient age was 33.9 ±â€Š14.1 years, and the mean postoperative follow-up period was 12 months. The average enophthalmos was 3.20 mm preoperatively, and the mean improvement at 6 months after surgery was 2.82 mm. One patient suffered a canalicular laceration after surgery, and another retrobulbar hemorrhage; however, both of these complications resolved with appropriate management. Otherwise, there were no significant surgical complications including newly developed diplopia, decreased visual acuity, or cerebrospinal fluid leakage. CONCLUSIONS: The endoscopic transcaruncular and transconjunctival approach is a useful and promising technique to repair combined medial and inferior orbital wall fractures.

Oxygen Plasma Treatment on 3D-Printed Chitosan/Gelatin/Hydroxyapatite Scaffolds for Bone Tissue Engineering.

The 3D hydroxyapatite/gelatin/chitosan composite scaffolds were fabricated by 3D printing technique. The scaffolds were treated by oxygen plasma to improve the bioactivity and its surface characterization and in vitro cell culture were investigated. The scaffolds exhibited the good porosity and interconnectivity of pores. After oxygen plasma etching, roughness and wettability on the scaffolds surface are increased. Plasma treated scaffolds showed higher proliferation than that of untreated scaffolds. Oxygen plasma treatment could be used as potential tool to enhance the biocompatibility on the 3D composite scaffolds.

Preparation of O2 Plasma Treated Polycaprolactone/Nano TiO2 Composites and In Vitro Bioactivity.

Polycaprolactone (PCL)/TiO2 composite films (PTCFs) were prepared by a solvent casting method at various concentrations of TiO2 (1, 3, 5, and 10 wt%) and then treated using oxygen plasma. The hydrophilicity of the oxygen plasma treated PTCFs increased as the treatment time was increased, due to the oxygen induced production of polar species at the surface of the PTCFs. In vitro bioactivities of the composite films were examined by immersion in simulated body fluid for up to 7 days. It was found that the oxygen plasma treatment significantly influenced the in vitro bioactivity of the PTCFs.

Osteoblastic cell response and bone formation of phosphate ion coated on plasma polymerized Ti surface.

This study examined the bone formation ability and cell response on a phosphate (PO3(4-)) ion exchanged amine plasma polymerized titanium (Ti) surface. The enhanced bone-like apatite (hydroxyapatite, HAp)-forming ability was attributed to the PO3(4-) ion exchanged amine plasma polymerized Ti (P/NH2/Ti) surface, which was formed by the reduction of PO3(4-) ions. PO3(4-) ions promote HAp nucleation and growth on Ti in SBF, and PO3(4-) ions improve the crystallinity of the HAp deposited layer. The cell viability tests revealed significantly greater cell viability on the P/NH2/Ti surfaces than on the other surfaces.

Clinical outcomes of epi-LASIK: 1-year results of on- and off-flap procedures with and without mitomycin-C.

AIM To evaluate and compare the clinical outcomes of epi-laser in situ keratomileusis (LASIK) performed either on-flap or off-flap with or without 0.02% mitomycin-C (MMC) in terms of corneal haziness, pain scores and satisfaction scores. METHODS In this non-randomised comparative retrospective study, the charts of 198 patients (394 eyes) who had undergone an epi-LASIK procedure for myopia (-1.5 D to -8.0 D spherical equivalent) correction were reviewed. Patients were classified into four groups: Group I, on-flap without MMC, 181 eyes; Group II, on-flap with MMC, 52 eyes; Group III, off-flap without MMC, 93 eyes; Group IV, off-flap with MMC, 68 eyes. We compared the group outcomes on the first day, 1, 3 and 6 months and 1 year after the operation. RESULTS The mean uncorrected visual acuity was significantly better in the off-flap groups (III and IV) than in the on-flap groups (I and II) on day 1 (p=0.002). There was no significant difference in the spherical equivalent among all groups at 1 year (p=0.305). Some degree of haziness was present in 10 eyes (Grade II: 2; Grade I: 8), but the haziness level was not significantly different among groups at 1 year (p=0.533). Pain scores (0-10) were lower in the off-flap groups (III and IV) (p=0.010). Satisfaction scores (0-10) were higher in the off-flap groups (III and IV), but the difference was not statistically significant (p=0.248). CONCLUSIONS Myopic correction by epi-LASIK surgery with all four methods showed stable visual results in terms of the 1-year postoperative clinical outcomes. Haziness levels revealed that treatment with 0.02% MMC was less effective than expected. Overall, the off-flap method offered faster visual recovery and less postoperative pain than the on-flap method.

Protective effects of epigallocatechin gallate after UV irradiation in cultured human retinal pigment epithelial cells.

PURPOSE: To evaluate the protective effects of Epigallocatechin gallate (EGCG) against UV irradiation in cultured human retinal pigment epithelial (RPE) cells. METHODS: UV irradiation was produced by a UV lamp for 30 seconds with an irradiance of 3.3 mW/cm2. After 5 minutes and 1 hour, we administered different concentrations of EGCG (0, 5, 10, 15, 25, 50, 100 uM). The cell count was determined under a microscope using a counting chamber and the cell activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The cell count of cultured human RPE cells after UV irradiation was markedly increased in the EGCG administration group, compared with the non-administrated group. The cell activity of the cultured human RPE cells after UV irradiation was markedly increased in the EGCG administration group and was increased in a dose-dependent way as determined by the MTT assay. CONCLUSIONS: The administration of EGCG increased the cell count and the cell activity after UV irradiation in cultured human retinal pigment epithelial cells; this suggests that EGCG provided protection against UV damage in cultured human retinal pigmented epithelial cells.