Cross-linking Treatment Research Articles

A novel, flexible porous nanofibrous hydrogel interfacial solar evaporator for highly efficient seawater and wastewater purification

Solar desalination is recognized as one of the eco-friendly and sustainable ways to alleviate the global freshwater crisis but still requires further research, especially in developing high-performance evaporators. Herein, we prepared an efficient carbon nanotubes (CNTs)@polyvinyl alcohol (PVA) nanofibrous hydrogel evaporator by electrospinning and subsequently chemical cross-linking treatment. Due to CNTs with good light absorption capacity, the evaporator exhibited an excellent light absorption capacity (>90%) throughout the full spectrum range (250–2500 nm). Meanwhile, the interconnected pores from electrospinning, as well as the intermediate water in the hydrogel, ensured the prepared evaporator with a favorable evaporation rate of up to 2.16 kg m−2 h−1 and photothermal conversion efficiency of ∼88.13% under one solar light intensity. For long-term seawater desalination, the CNTs@PVA nanofibrous hydrogel evaporator also presented superior salt resistance, durability and good self-cleaning properties. Besides, various non-volatile pollutants can be completely removed by the prepared evaporator during the wastewater purification. As a result, this work is considered to provide a new direction for developing high-performance evaporators to provide freshwater through seawater desalination and wastewater purification.

Choroidal thickness assessment in keratoconus patients treated with cross-linking compared to healthy population

PurposeTo analyze the choroidal thickness between patients with keratoconus undergoing cross-linking treatment and a healthy population, as well as to determine the factors that influence choroidal thickness.MethodsThis was an observational, analytical, case–control study that was conducted from February 2021 to June 2021. Choroidal thickness was measured at different locations, including the subfoveal, nasal (1000 μm), temporal (1000 μm), superior (1000 μm) and inferior (1000 μm) locations using a Spectral-domain optical coherence tomography with enhanced depth imaging, which allowed us to obtain horizontal and vertical B-scans centered on the fovea.ResultsThis study included 21 patients with keratoconus (mean age, 21.86 ± 5.28 years) and 28 healthy patients (mean age, 24.21 ± 4.71 years). Choroidal thickness was significantly greater in patients with keratoconus than in healthy patients in each of the following measured locations: subfoveal (P < 0.001); nasal (1000 μm) (P < 0.001), temporal (1000 μm) (P < 0.001), superior (1000 μm) (P < 0.001) and inferior (1000 μm) (P < 0.001) locations. Variables such as age (ρ = − 0.09; P = 0.50) and refraction (ρ = 0.14; P = 0.34) were not found to be associated with choroidal thickness. In a stepwise multiple linear regression, the group was the single variable correlated with choroidal thickness (β = 0.88; P < 0.001).ConclusionChoroidal thickness is thicker in keratoconus patients treated with cross-linking than in the healthy population. This finding could be associated with inflammatory choroidal mechanisms in keratoconus patients, but more studies are needed. Age and refractive error do not seem to influence choroidal thickness.

Outcomes of Corneal Topographical Kmax readings 3 months after Corneal Cross Linkage in Keratoconus patients.

Background and objectiveCollagen protein, which is abundant in the cornea and has a triple helix form, may be found in almost every tissue matrix in the body. Natural cross connections between monomers provide the robustness of the helical protein structure. Wollensak and his colleagues developed the Dresden Protocol, a keratoconus treatment based on Corneal Cross-Linkage. We aimed to analyse and present the findings in individuals with progressive keratoconus using topographic and refractive results after corneal collagen crosslinking treatment (CXL) (KC) after 3 months.MethodsThe study comprises a total of 100 patients who were diagnosed with progressive KC and who underwent CXL between 2021 and 2022 at KRL Hospital Islamabad, Pakistan. All eyes in this study had a preoperative topography within 1 month before CXL treatment and the follow-ups were conducted at 3 months interval.ResultsIn our investigation, 100 patients were added. The average age was 24.74 years. 77% of the patients were between the ages of 12 and 25 years, while 23% were between the ages of 26 and 50 years. In our survey, males made up 84% of the population, while females made up only 16%. The right eye was afflicted in 60% of cases, whereas the left eye was impacted in 40% of the population. Grade 2 Keratoconus affected 42% of patients, whereas Grade 1 Keratoconus affected 18%. Our findings were skewed toward men and the 12–25 age group, however in our recent study, we discovered considerable KC stability 3 months after CXL.ConclusionKeratometric readings and visual acuity were stabilised or improved with CXL treatment. Keratoconus stability can be reached 3 months following the treatment, according to our findings.

Microwave-initiated modification of polyamide 6.6 fabric surfaces for superior hydrophilic and flame retardant properties

Microwave-assisted surface modification of polyamide 6.6 (PA6.6) fabrics was carried out in a grafting polymerization technique in the presence of acrylic acid (AA) monomer with an aim to enhance the extent of surface functional groups onto the PA6.6 fabric surfaces. In the next step, the surface modified fabric substrate was gone through a layer by layer (LbL) deposition process in the presence of some hybrid (organic/inorganic) polyelectrolytes in imparting hydrophylic and flame retardant properties and finally, the as prepared coating was subjected to a cross-linking treatment aided by hypo-phosphorus acid (HP) in enhancing the stability of the same. From the obtained results, it was revealed that the simultaneous microwave assisted grafting, LbL deposition and HP cross-linking left positive impacts in improving the flame retardant performance and hydrophilicity of PA6.6 fabrics along with the enhancement of coating stability in laundering. For example, acrylic acid grafted PA6.6 fabric sample with a 5-BL deposition and cross-linked with HP (i.e., PA6.6-g-AA-5BL-HP) attained a limiting oxygen index (LOI) value up to 23.5%, while exhibiting a significant level of reduction in the peak heat release rate (pHRR) by ca. 50 %. In line, a super-hydrophilic surface was obtained for this fabric sample as the water contact angle value declined to 0º. Furthermore, such kind of surface modification displayed a considerable level of coating stability during laundering as the anti-dripping properties still exist even after 10 home launderings.

Çocuk ve erişkin Keratokonus hastalarında hızlandırılmış çapraz bağlama tedavisi sonrası Scheimpflug Kornea Dansitometri analizi

Amaç: On sekiz yaş altı ve 18 yaş üstünde keratokonus nedeniyle çapraz bağlama tedavisi (ÇB) uygulanan hastalardaki korneal dansitometri değişimlerini karşılaştırmalı olarak değerlendirmektir. Yöntem: Keratokonus tanısıyla ÇB uygulanan 55 hastanın 74 gözü çalışmaya alındı. 18 yaş ve altındaki hastalar grup 1’e dahil edilirken, 18 yaş üstündeki hastalar grup 2’ye dahil edildi. Hastaların ÇB öncesinde ve sonrasında Pentacam Scheimpflug görüntüleme sistemi ile kornea kalınlığı ve korneal dansitometri değerleri ölçülerek kaydedildi. Çapraz bağlama sonrası tüm hastaların kornea kalınlıkları ultrasonik pakimetri ile de ölçüldü ve Scheimpflug sistem ölçümleri ile karşılaştırma yapıldı. Bulgular: Grup 1’de ÇB öncesindeki korneal dansitometri değeri 19.84±2.67 GSU iken, işlem sonrası 21.54±3.32 GSU idi ve aradaki fark istatistiksel olarak anlamlıydı (p=0.048). Benzer şekilde Grup 2’deki dansitometri değeri ÇB öncesinde 18.74±1.56 GSU iken, işlem sonrasında 24.53±10.46 GSU idi ve aradaki fark anlamlıydı (p&amp;lt;0.0001). Grup 1’de Scheimpflug görüntüleme sistemi ile ÇB öncesi ölçülen kornea kalınlığı 473.04±24.23 µ iken, grup 2’de 467.89±29.09 µ idi. Her iki grupta ÇB sonrası kornea kalınlıkları sırasıyla 461.88±27.64 µ ve 446.42±32.76 µ idi ve aradaki fark iki grupta da istatistiksel olarak anlamlıydı (sırasıyla p=0.003, p&amp;lt;0.0001). Sonuç: Keratokonus hastalarında, ÇB sonrasında, çocuk ve erişkinlerde korneal bulanıklık oluşmaktadır. Erişkinlerde çocuklara göre daha fazla bulanıklık olmaktadır. Bulanıklığın takibinde korneal dansitometri objektif veriler sunar. Bulanıklık olan kornealarda kalınlık takibi için ultrasonik pakimetri, Scheimpflug kameraya göre daha doğru ölçümler sunabilir.

Minimising chemical crosslinking for stabilising collagen in acellular bovine pericardium: Mechanistic insights via structural characterisations

Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability, crosslinkers are used in excess, with stability guided by indicators including the hydrothermal denaturation temperature, the enzymatic resistance and the degree of crosslinking. Yet, understanding of the intermolecular structure in collagen fibrils which imparts the intrinsic stability of the ABPs is lacking, and the discrepancies in the stability criteria in varied conditions are poorly explained. In this study, synchrotron small-angle X-ray scattering (SAXS) in combination with thermal and colorimetric methods are employed to investigate the changes in the structure and the stability of ABPs during crosslinking using glutaraldehyde (GA) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) at different concentrations. Based on the findings, a mechanism is proposed to explicate the crosslinking effects on collagen structure and the relationship between the structure and each stability indicator. At low crosslinker concentrations, the telopeptidyl-helical linkages are preferred, which cause rearrangements in the intermolecular structure of collagen, and efficiently contribute to its stabilities. Excess crosslinking is revealed by a revert trend in structural changes and the plateauing of the stabilities, assigning to the helical-helical linkages and monovalent bindings. The former would improve thermal stability but not collagenase resistance, whereas the latter have negligible effects. Overall, this study provides a mechanistic understanding of the chemical crosslinking of ABPs, which will contribute to the future development of more efficient and economically viable strategies to produce bioprostheses. Statement of significanceChemical crosslinking imparts suitable properties to acellular bovine pericardium (ABP) for clinical applications, yet the understanding is lacking on the structure-stability relationship especially under different crosslinking conditions. Structural evidence in this study differentiates the binding sites during crosslinking in collagen fibrils at different crosslinker concentrations, highlighting the excess usage in the conventional crosslinking treatments. The mechanism based on the structure of collagen also successfully explains the dissimilarity in hydrothermal and enzymatic stabilities with varied crosslinking conditions. Future researches focusing on developing biomaterials via chemical crosslinking of ABPs would benefit from this study, for its contribution to the better understanding of the relationship of collagen structure and functions.

Physical and Natural Crosslinking Approaches on Three-Dimensional Gelatin Microspheres for Cartilage Regeneration.

The use of gelatin microspheres (GMs) as a cell carrier has been extensively researched. One of its limitations is that it dissolves rapidly in aqueous settings, precluding its use for long-term cell propagation. This circumstance necessitates the use of crosslinking agents to circumvent the constraint. Thus, this study examines two different methods of crosslinking and their effect on the microsphere's physicochemical and cartilage tissue regeneration capacity. Crosslinking was accomplished by physical (dehydrothermal [DHT]) and natural (genipin) crosslinking of the three-dimensional (3D) GM. We begin by comparing the microstructures of the scaffolds and their long-term resistance to degradation under physiological conditions (in an isotonic solution, at 37°C, pH = 7.4). Infrared spectroscopy indicated that the gelatin structure was preserved after the crosslinking treatments. The crosslinked GM demonstrated good cell adhesion, viability, proliferation, and widespread 3D scaffold colonization when seeded with human bone marrow mesenchymal stem cells. In addition, the crosslinked microspheres enhanced chondrogenesis, as demonstrated by the data. It was discovered that crosslinked GM increased the expression of cartilage-related genes and the biosynthesis of a glycosaminoglycan-positive matrix as compared with non-crosslinked GM. In comparison, DHT-crosslinked results were significantly enhanced. To summarize, DHT treatment was found to be a superior approach for crosslinking the GM to promote better cartilage tissue regeneration.

Modification methods of soy protein adhesive and its application

Soybean protein adhesive is loved by the society because of its low price, simple preparation, non-toxicity to the environment and easy decomposition. However, the soybean protein adhesive itself is easy to crack when exposed to water, the viscosity is insufficient, and there are many changes in individual users. This research will describe several methods of modifying soy protein to enhance various properties of soy protein adhesives. The first method is heat treatment, which folds the molecules of the soy protein adhesive to strengthen it. The second is a cross-linking treatment that allows soy protein to form a network with other agents to enhance its structure through chemical bonds. The third is graft copolymerization, where other agents are grafted onto the soy protein adhesive to give it some good properties. The fourth is blending, where the soy protein adhesive is mixed with other adhesives so that the new homogeneous mixture has the properties of both adhesives. And with the development of these researches, application of the modified soybean protein adhesives is further introduced.

High efficient fire-retardant coatings on wood fabricated by divalent metal ion cross-linked multilayer polyethyleneimine and ammonium polyphosphate polyelectrolytes

In this work, to endow wood with efficient flame retardancy, polyethyleneimine (PEI) and ammonium polyphosphate (APP) as an intumescent flame retardant system was deposited on wood via layer-by-layer (LbL) self-assembly approach combined with divalent metal ions cross-linking treatment. Scanning electron microscopy equipped with energy-dispersive (SEM-EDX) and Fourier transform infrared spectroscopy (FT-IR) analysis demonstrated that divalent metal ions cross-linked PEI-APP coatings were successfully constructed on wood surface. Thermogravimetric analysis (TGA) indicated that PEI-APP modification could improve the thermal stability of coated wood by decreasing the maximum degradation rate and increasing the char residue, while Cu2+ and Co2+ cross-linking treatments could further enhance these properties. What's more, the fire resistance of the modified wood was also significantly improved, proved by limiting oxygen index (LOI) and cone calorimeter characterizations. When coated by PEI-APP, the LOI was increased to 37.5 from the pristine uncoated 23.5. Further, when cross-linked by Cu2+ and Co2+, the LOIs were increased to 47 and 42.5, respectively. In addition, the heat release rate (HRR) and total heat release (THR), especially the total smoke release of the PEI-APP and metal ions cross-linked coated wood, were also obviously decreased. The improvement of thermal stability and fire-retardant performance was mainly due to the synergistic effect of APP and metal ions, which could accelerate the char-forming process and increase the amount of carbon formed, thus effectively preventing the spread of heat and flame into the inner wood and protecting the wood from fire attacking. The green and low-cost flame-retardant treatment approach reported in this study is likely to improve the added value of modified wood and promote its wide application.

Abstract P1126: Development Of A Tissue Engineered Small Vascular Graft With Human Amnion Membrane

The vascular transplantation is an established therapy for vascular diseases by replacing or bypassing the damaged blood vessel with a functional vascular graft. Autologous blood vessels are considered as the gold standard grafts for vascular transplantation, but the limited tissue source and the high morbidity associated with tissue harvesting have restricted their therapeutic potential. Vascular tissue engineering represents an alternative solution to replace the autologous blood vessels by developing an artificial conduit which can closely mimic the nature blood vessel. However, clinical trials with small vascular grafts are disappointing. The aim of this study is to investigate the feasibility of constructing a small vascular graft from the decellularized amniotic membrane (DAM graft) via different crosslinking methods. The human amnion membrane was decellularized, trimmed into 5 cm x 8 cm rectangular shape, and rolled around a catheter (diameter =1.2 mm) to make the primary DAM graft. Each of the resulting conduits was additionally crosslinked with: a) 0.1% glutaraldehyde; b) 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (20mM) / N-hydroxy succinimide (10mM) (EDC-NHS); c) 0.5% genipin; and d) no-crosslinking as control group. Our results demonstrated the structural integrity, material stability, mechanical behaviors, and biocompatibilities of the DAM grafts can be modified by the chemical crosslinking treatment. In which, the genipin crosslinked DAM graft exhibited the most integrated layered structure. Its level of material stability was comparable to those of the glutaraldehyde and the EDC-NHS crosslinked DAM grafts. Furthermore, the genipin crosslinking did not significantly affect the mechanical properties of the DAM graft. The genipin-crosslinked DAM graft was further tested in vivo by implanting it in a rat abdominal aorta replacement-model. All rats implanted with the genipin-crosslinked DAM graft exhibited a blood vessel patent up to 9-month post-implantation. In conclusion, we represented a potential avenue to construct a flexible vascular graft that has the patient-specific dimension and meet specific demands for biological and mechanical performance criteria by using the DAM followed by lyophilization and the genipin.

Green chemistry method for hair strengthening and setting using visible light-mediated protein crosslinking

A clean and nontoxic one-step protein crosslinking reaction method induced by visible light was developed using eco-friendly chemicals, such as riboflavin phosphate (RFP), citric acid (CA), and polyols . In this study, oxygen radicals generated by blue light (BL)-irradiated RFP replace the conventional free thiol generatio step of the alkali condition. CA and polyol were used as crosslinkers and extenders , respectively, to enhance keratin crosslinking in hair. The new one-step crosslinking method was compared with the existing permanent hair waving treatment using thioglycolic acid (TGA). Compared to TGA treatment, the newly proposed crosslinking method induced minor damage to hair and keratin. In addition, the mechanical property changes were measured after crosslinking treatment on the hair. The tensile stress values and Young's moduli of the treated hair samples were approximately 1.3 and 2.2 times higher than untreated hair. The hair-setting effect was also confirmed by the changes in the radii of the hair fibers and the length of the hair tresses after crosslinking treatment. Therefore, we believe that the clean one-step crosslinking technology can be used to develop eco-friendly products for hair strengthening and setting. • Clean one-step crosslinking of keratin is effective in strengthening and setting hair. • Keratin crosslinking is induced by exposure to blue light in the presence of RFP. • Citric acid and polyols form extender acts as a linker for keratin crosslinking.

Comparison of Accelerated and Standard Corneal Collagen Cross-Linking Treatments in Experimental Fungal Keratitis for Aspergillus fumigatus.

Introduction To compare accelerated and standard corneal collagen cross-linking (CXL) treatments in experimental Aspergillus keratitis models. Methods Twenty-six New Zealand rabbits were divided into two groups: a 1% voriconazole combined with standard CXL group, and a 1% voriconazole combined with accelerated CXL group. The ulcer area, corneal opacity, and corneal neovascularization score were measured via slit-lamp imaging, and the corneal and corneal epithelial thickness and ulcer depth were measured via anterior segment optical coherence tomography (AS-OCT). The duration of the hyphae was observed via in vivo confocal microscopy (IVCM), and the cornea was taken for pathological examination after modeling and at the end of the study to determine the hyphae and corneal repair. The observation times were as follows: at successful modeling (day 0) and at 1, 4, 7, 14, 21, and 28 days after the intervention. Results The area and depth of the ulcer decreased in both groups after CXL (all P < 0.05). Interestingly, the ulcer area in the accelerated CXL group still tended to increase on the first day after CXL although the difference was not statistically significant (P=0.6649). On the 21st and 28th days after CXL, the ulcer area and depth of the standard CXL group were larger and deeper than those of the accelerated CXL group (all P < 0.05). The ulcer healing time in the accelerated CXL group was 18.67 ± 6.21 days, while that in the standard CXL group was 23.55 ± 4.72 days, and the difference was statistically significant (P=0.0475). Conclusions Both accelerated and standard CXL can significantly inhibit the progression of Aspergillus keratitis corneal ulcers and promote ulcer healing. The accelerated CXL was superior to the standard CXL, which could control infection faster and promote ulcer healing. However, it is important to note that there may be a risk of early deterioration of the ulcer with accelerated CXL.

Changes in retinal vessel and retinal layer thickness after cross-linking in keratoconus via swept-source OCT angiography.

To analyze the postoperative foveal avascular zone (FAZ) area, superficial capillary plexus (SCP), deep capillary plexus (DCP) vascular densities (VD), and retinal layers after cross-linking (CXL) for keratoconus treatment. Twenty-seven eyes with cross-linking treatment for keratoconus were included in the study. Foveal avascular zone (FAZ) area, SCP VD, DCP VD, and retinal layers were evaluated by using optical coherence tomography angiography (OCTA). OCTA measurements were made at preoperative, first week, and first and sixth months after the surgery. In addition, corneal topography measurements were also made. Although there was a decrease in corneal thickness in the follow-up of the patients, there was no significant difference in axial length and anterior chamber depth. There was no significant difference in full retinal thickness in the foveal and parafoveal areas. While there was a significant increase in retinal nerve fiber layer (RNFL) thickness in the foveal area (p = 0.032, p = 0.015, p = 0.017; preoperative values compared to first week, first month, and sixth month respectively), there was a decrease in ganglion cell layer (GCL) thickness in the parafoveal area in the postoperative sixth month (p = 0.028). There was no difference in FAZ measurements. In the parafoveal area, a decrease was observed in SCP VD in the sixth-month control (p = 0.019). There was a significant increase in DCP VD in the foveal area (p = 0.008, p = 0.043, p = 0.040). The preoperative mean CDVA (corrected distance visual acuity) was 0.37 ± 0.16 logMAR and postoperative sixth month mean CDVA was 0.39 ± 0.15. There was no significant difference in visual acuity(p = 0.71). Keratoconus patients successfully treated with CXL had significant changes in retinal layers and vessel density in the superficial and deep retinal plexus.

IDO Inhibitor and Gallic Acid Cross-Linked Small Molecule Drug Synergistic Treatment of Melanoma.

In this study, we synthesized a molecule GA-1MT (GM) composed of indoleamine 2,3-dioxygenase (IDO) inhibitor (1-methyl-d-tryptophan, 1MT) called NLG8189 and gallic acid (GA) and verified its therapeutic effect on B16F10 melanoma cells and an orthotopic tumor-bearing mouse model. The synthesized molecule GM was analyzed by 1H NMR and mass spectrometry (MS). In addition, we confirmed that GM could mediate the immune response in the B16F10 cell tumor model by flow cytometry and immunofluorescence. The synthesized GM molecule could increase the solubility of 1MT to enhance the drug efficacy and lower costs. Moreover, GM could inhibit melanoma growth by combining 1MT and GA. In vivo experiments showed that GM could effectively inhibit the expression of tyrosinase, regulate the proportion of CD4+ T cells, CD8+ T cells, and regulatory T cells (Treg cells) in tumors, and significantly suppress melanoma growth. The newly synthesized drug GM could more effectively inhibit melanoma than GA and 1MT alone or in combination.

Comparison of Corneal Collagen Cross-Linking and Voriconazole Treatments in Experimental Fungal Keratitis for Aspergillus fumigatus.

AimsTo compare the antifungal efficacy of corneal cross-linking (CXL) and voriconazole in experimental Aspergillus keratitis models.MethodsThirty-nine New Zealand rabbits were divided into three groups: a control group, a voriconazole group (M group), and a voriconazole combined with CXL group (CXL-M group). The ulcer area was measured via slit lamp imaging, the corneal and corneal epithelial thickness, and ulcer depth was measured via anterior segment optical coherence tomography (AS-OCT). The existence time of the hyphae was observed via in vivo confocal microscopy (IVCM), and the cornea was taken for pathological examination after modeling and at the end of the study to determine the hyphae and corneal repair. The observation times were as follows: at successful modeling and at 1, 4, 7, 14, 21, and 28 days after intervention.ResultsIn the CXL-M group, ulcer area and depth decreased continuously from Day 4 to Day 28 after CXL (all P < 0.05). In the CXL-M group, ulcer area and depth were smaller than those in the other two groups from Day 4 to Day 21 after CXL (all P < 0.05, except ulcer area in the CXL-M vs. M group on Day 21). The duration of hyphae in the CXL-M group was significantly shorter than in the other two groups (P = 0.025). On Day 28, in CXL-M group, corneal thickness was thicker than baseline (P < 0.05). Meanwhile, in CXL-M group, corneal and corneal epithelial thickness were significantly thinner than in the other two groups (P < 0.001). The CXL-M group had no complications, such as corneal perforation, at the end of the study.ConclusionsVoriconazole combined with CXL is effective in treating Aspergillus-infected keratitis. Combined therapy could effectively inhibit Aspergillus, accelerate corneal repair, and shorten the course of the disease.

Comparison of accelerated corneal cross-linking for progressive keratoconus in pediatric and adult age groups: One-year results

To compare one-year results of accelerated cross-linking (ACXL) treatment for progressive keratoconus in pediatric and adult age groups. The records of patients who had undergone the ACXL procedure (9mV/cm2, 10min) for progressive keratoconus were evaluated retrospectively. The patients were divided into 2 groups, with the pediatric group aged 17years or less and the adult group aged 18years or more, for the statistical analysis. Pre- and 12-month post- ACXL best-corrected visual acuity (BCVA), maximum keratometry (Kmax), sim K1, sim K2, corneal thickness at the thinnest point (thCT), and corneal astigmatism (CA) values of the patient groups were recorded. Thirty-two right eyes of 32 patients were included in the pediatric group, and 32 right eyes of 32 patients were included in the adult group. A significant improvement in BCVA and a significant decrease in thCT values were present in both groups 12months after the surgery compared to the preoperative period. The decrease in Kmax, sim K1 and sim K2 values compared to the preoperative period was significant in the adult group. When the two groups were compared after 12months, only the simK1 value was significantly lower in the adult group, and there was no significant difference between the other measurements. There is a slight tendency toward more flattening in the adult group 12months after ACXL treatment, but this is not statistically significant.

Corneal stromal depth of the demarcation line after accelerated versus conventional cross-linking

Background: Keratoconus is one of ectatic corneal disease which is characterized by corneal steepening, visual distortion, apical corneal thinning, and central corneal scarring. Its exact etiology is unknown. Aim and objectives: to assess the depth of the corneal stromal demarcation line (a transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma,which is considered a measurement of the depth of cross-linking treatment into the stroma). 6 After conventional crosslinking versus accelerated crosslinking after one and three months postoperative. Subjects and methods: This Prospective, randomized, comparative, cross-sectional study was conducted in Kobri El Qobba Military specialized eye hospital, Cairo, Egypt. This study was conducted on 40 eyes with progressive keratoconus divided into two groups, each of them included 20 eyes: group 1: 20 eyes underwent accelerated cross-linking, and group 2: 20 eyes underwent conventional (standard) cross-linking. Results: The demarcation line and Kmax at 1-month and 3-months postoperative showed no statistically difference between the two studied groups. Conclusion: cross-linking is a safe and efficient treatment in progressive keratoconus. Accelerated CXL was comparable with conventional CXL at all-time points and both conventional and accelerated CXL significantly improve CCT and Demarcation line depth.

PEGDA-SN as Both Solid-State Electrolyte and Solid-Solid Interface Material for Li-O2 Battery

The solid-state batteries have received widespread attention due to their excellent stability and safety, however, the low ionic conductivity and weak interface contact always restricted its performance. In this work, we propose an in situ thermally cross-linked and solidified polymer electrolyte with polyethylene glycol diacrylate (PEGDA) as scaffold in which succinonitrile (SN) and lithium bis-trifluoromethanesulfonimide (LiTFSI) were further introduced to improve the ionic conductivity. Herein, the composite gel was served as not only solid-solid interface material but also solid-state electrolyte. Different with conventional polymer gels, the solvent evaporation could not happen for this composite material during the solidification process, and therefore resulting in good interface contact without inside bubbles. We further present the investigation on transport principle of Li+ in the solid-state electrolyte and the effect of molecular chain on ionic conductivity. The conductivity of the solid-state electrolyte can reach 1.76 × 10−4 S cm−1 at room temperature without any assistance of liquid electrolytes, which is attributed to the short molecular chain of PEGDA. Electrochemical window of the solid-state electrolyte can reach 5.2 V after cross-linking treatment. And the lithium-oxygen battery using this solid-state electrolyte can stably cycle for more than 1100 cycles with a current density of 200 mA g−1 and a limit capacity of 200 mAh g−1 at room temperature.

Topography versus non-topography-guided photorefractive keratectomy with corneal cross-linking variations in keratoconus.

To compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus. Interventional and comparative prospective study. Sixty-nine eyes (36 patients) suffering from keratoconus (stages 1 Amsler-Krumeich classification) were divided into four groups: sequential topography-guided photorefractive keratectomy with CXL, simultaneous topography-guided photorefractive keratectomy with CXL, simultaneous non-topography guided photorefractive keratectomy with CXL, and sequential non-topography guided photorefractive keratectomy with CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry. All analyzed visual, contrast sensitivity, and refractive parameters showed a significant improvement in the four groups (all P<0.05). A noticeable improvement was seen in keratometry in all the groups, and a remarkable difference was observed between topography-guided groups in comparison to non-topography-guided groups (P<0.05). Interestingly, the improvement in all parameters showed a degree of stability to the end of the follow-up. The treatment priorities in all four groups are safety, efficacy, and predictability in the correction of the sphero-cylindrical errors in mild and moderate keratoconus. No significant differences among groups in the recorded objective outcomes were found.

Dynamics of keratoconus progression after a previous successful accelerated crosslinking treatment during and after pregnancy.

To evaluate the effectiveness of previously applied successful accelerated corneal crosslinking (CXL) treatment in keratoconus stabilization during and after pregnancy. Ankara Yildirim Beyazit University, Ataturk Training and Research Hospital, Turkey. Prospective clinical study. Patients with stable keratoconus (after having an accelerated CXL procedure) who became pregnant were included. Uncorrected (UDVA) and corrected distance visual acuity (CDVA), manifest astigmatism (MA), keratometry (K)1, K2, Kmax, central corneal thickness (CCT), thinnest corneal thickness (TCT), and anterior (AE) and posterior elevation (PE) were recorded at baseline (before CXL), before pregnancy (the last visit after CXL), during pregnancy (third trimester), and after pregnancy (the last visit after pregnancy). 24 eyes of 19 patients were included. The mean time between CXL and conception was 12.4 ± 5.1 months. The mean postpartum follow-up period was 27.6 ± 13.3 months. The mean UDVA, CDVA, MA, and PE values did not show any statistically significant differences during and after pregnancy compared with the post-CXL values (P > .05). The mean Kmax flattened significantly after the CXL procedure (P = .011); however, it increased during pregnancy (P = .037, after CXL vs pregnancy) and then decreased back to the prepregnancy level after pregnancy (P = .035, pregnancy vs after pregnancy). The mean K1, K2, AE, CCT, and TCT remained stable during pregnancy and significantly decreased after pregnancy (P < .05). Keratoconus seems to progress during pregnancy in corneas that have previously received successful accelerated CXL treatment. However, this progress was mostly temporary, and generally, regression occurred after delivery.