Sharifi S, Sharifi H, Akbari A, Chodosh J.
Systematic optimization of visible light-induced crosslinking conditions of gelatin methacryloyl (GelMA). Sci Rep 2021;11(1):23276.
AbstractGelatin 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. Eosin Y, in combination with TEOA and VC, is a biosafe photoinitiation system that can be activated via visible light instead of UV and bypasses those biosafety concerns; however, the crosslinking system needs fine-tuning and optimization. In order to systematically optimize the crosslinking conditions, we herein independently varied the concentrations of Eosin Y [(EY)], triethanolamine (TEOA), vinyl caprolactam (VC), GelMA precursor, and crosslinking times and assessed the effect of those parameters on the properties the hydrogel. Our data showed that except EY, which exhibited an optimal concentration (~ 0.05 mM), increasing [TEOA], [VA], [GelMA], or crosslinking time improved mechanical (tensile strength/modulus and compressive modulus), adhesion (lap shear strength), swelling, biodegradation properties of the hydrogel. However, increasing the concentrations of crosslinking reagents ([TEOA], [VA], [GelMA]) reduced cell viability in 3-dimensional (3D) cell culture. This study enabled us to optimize the crosslinking conditions to improve the properties of the GelMA hydrogel and to generate a library of hydrogels with defined properties essential for different biomedical applications.
Shen J, Rossato FA, Cano I, Ng YSE.
Novel engineered, membrane-tethered VEGF-A variants promote formation of filopodia, proliferation, survival, and cord or tube formation by endothelial cells via persistent VEGFR2/ERK signaling and activation of CDC42/ROCK pathways. FASEB J 2021;35(12):e22036.
AbstractTherapeutic angiogenesis would be clinically valuable in situations such as peripheral vascular disease in diabetic patients and tissue reperfusion following ischemia or injury, but approaches using traditional isoforms of vascular endothelial growth factor-A (VEGF) have had little success. The isoform VEGF165 is both soluble and matrix-associated, but can cause pathologic vascular changes. Freely diffusible VEGF121 is not associated with pathologic angiogenesis, but its failure to remain in the vicinity of the targeted area presents therapeutic challenges. In this study, we evaluate the cellular effects of engineered VEGF variants that tether extracellular VEGF121 to the cell membrane with the goal of activating VEGF receptor 2 (VEGFR2) in a sustained, autologous fashion in endothelial cells. When expressed by primary human retinal endothelial cells (hRECs), the engineered, membrane-tethered variants eVEGF-38 and eVEGF-53 provide a lasting VEGF signal that induces cell proliferation and survival, increases endothelial permeability, promotes the formation of a cord/tube network, and stimulates the formation of elongated filopodia on the endothelial cells. The engineered VEGF variants activate VEGFR2, MAPK/ERK, and the Rho GTPase mediators CDC42 and ROCK, activities that are required for the formation of the elongated filopodia. The sustained, pro-angiogenic activities induced by eVEGF-38 and eVEGF-53 support the potential of engineered VEGF variants-overexpressing endothelial cells as a novel combination of gene and cell-based therapeutic strategy for stimulating endothelial cell-autologous therapeutic angiogenesis.
Siddiqui N, Chen EM, Parikh R, Douglas VP, Douglas KA, Feng PW, Armstrong GW.
Epidemiology of United States Inpatient Open Globe Injuries from 2009-2015. Ophthalmic Epidemiol 2021;28(6):469-478.
AbstractPURPOSE: To study the epidemiology of inpatient open globe injuries (OGI) in the United States (US). METHODS: This was a retrospective cohort study of patients with a primary diagnosis of OGI in the National Inpatient Sample (NIS) from 2009 to 2015. Sociodemographic characteristics, including age, gender, race, ethnicity, insurance, and income were stratified for comparison. Annual prevalence rates were calculated using 2010 US Census data. Statistical analysis included Chi-square tests, ANCOVA, and Tukey tests. RESULTS: A total of 6,821 US inpatient hospital discharge records met inclusion/exclusion criteria. The estimated national prevalence of OGI during the 5-year period from 2009 to 2015 was 34,061 (95% confidence interval [CI] 31,445-36,677). The overall annual prevalence rate was 1.58 per 100,000 per year (CI 1.56-1.59). Overall, average annual prevalence rates were highest among patients 85 years or older (7.72, CI 6.95-8.49), on Medicare (3.92, CI 3.84-4.00), males (2.28, CI 2.25-2.30), African Americans (2.38, CI 2.32-2.44), and Native Americans (1.80, CI 1.62-2.00). OGI rates were lowest among Whites (1.21, CI 1.19-1.22), females (0.89, CI 0.87-0.91), those with private insurance (0.84, CI 0.82-0.86), and Asians (0.69, CI 0.64-0.74). Being in the lowest income quartile was a risk factor for OGI (p < .05). CONCLUSIONS: Inpatient OGIs disproportionately affected those over 85, young males, elderly females, patients of African-American descent, on Medicare, and in the lowest income quartile. Additionally, children and young children had lower rates of OGI compared to adolescents. Further studies should delineate causes for socioeconomic differences in OGI rates to guide future public health measures.
Sobel RK, Aakalu VK, Vagefi RM, Foster JA, Tao JP, Freitag SK, Wladis EJ, McCulley TJ, Yen MT.
Orbital Radiation for Thyroid Eye Disease: A Report by the American Academy of Ophthalmology. Ophthalmology 2021;
AbstractPURPOSE: To review the current literature on the safety and efficacy of orbital radiation for the management of thyroid eye disease (TED). METHODS: A literature search was conducted last in February 2021 of the PubMed database to identify all articles published in the English language on original research that assessed the effect of orbital radiation on TED. The search identified 55 articles, and 18 met the inclusion criteria for this assessment. A panel methodologist then assigned a level of evidence rating for each study, and all of them were rated level III. RESULTS: Two large retrospective studies demonstrated the efficacy of radiation treatment, with or without corticosteroid use, in preventing or treating compressive optic neuropathy (CON). Three studies highlighted the role of orbital radiation therapy (RT) to facilitate the tapering of corticosteroids. Several other studies showed a possible role for RT to improve diplopia and soft tissue signs. CONCLUSIONS: Although no level I or level II evidence exists, the best available evidence suggests that orbital radiation, used with or without corticosteroids, is efficacious in preventing CON, improving motility restriction, and decreasing clinical activity in TED. Orbital radiation also may facilitate a corticosteroid taper. Together, these studies show that RT seems to modify the active phase of TED. Short-term risks of orbital radiation are minor, but long-term outcome data are lacking.
Sun JK, Josic K, Melia M, Glassman AR, Bailey C, Chalam KV, Chew EY, Cukras C, Grover S, Jaffe GJ, Lee R, Nielsen JS, Thompson DJS, Wiley HE, Ferris FL, Ferris FL.
Conversion of Central Subfield Thickness Measurements of Diabetic Macular Edema Across Cirrus and Spectralis Optical Coherence Tomography Instruments. Transl Vis Sci Technol 2021;10(14):34.
AbstractPurpose: Develop equations to convert Cirrus central subfield thickness (CST) to Spectralis CST equivalents and vice versa in eyes with diabetic macular edema (DME). Methods: The DRCR Retina Network Protocol O data were split randomly to train (70% sample) and validate (30% sample) conversion equations. Data from an independent study (CADME) also validated the equations. Bland-Altman 95% limits of agreement between predicted and observed values evaluated the equations. Results: Protocol O included 374 CST scan pairs from 187 eyes (107 participants). The CADME study included 150 scan pairs of 37 eyes (37 participants). Proposed conversion equations are Spectralis = 40.78 + 0.95 × Cirrus and Cirrus = 1.82 + 0.94 × Spectralis regardless of age, sex, or CST. Predicted values were within 10% of observed values in 101 (90%) of Spectralis and 99 (88%) of Cirrus scans in the validation data; and in 136 (91%) of the Spectralis and 148 (99%) of the Cirrus scans in the CADME data. Adjusting for within-eye correlations, 95% of conversions are estimated to be within 17% (95% confidence interval, 14%-21%) of CST on Spectralis and within 22% (95% confidence interval, 18%-28%) of CST on Cirrus. Conclusions: Conversion equations developed in this study allow the harmonization of CST measurements for eyes with DME using a mix of current Cirrus and Spectralis device images. Translational Relevance: The CSTs measured on Cirrus and Spectralis devices are not directly comparable owing to outer boundary segmentation differences. Converting CST values across spectral domain optical coherence tomography instruments should benefit both clinical research and standard care efforts.