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Cartilage tissue is prone to degradation and has little capacity for self-healing due to its avascularity. Tissue engineering, which provides artificial scaffolds to repair injured tissues, is a novel and promising strategy for cartilage repair. 3D bioprinting offers even greater potential for repairing degenerative tissue by simultaneously integrating living cells, biomaterials, and biological cues to provide a customized scaffold. With regard to cell selection, mesenchymal stem cells (MSCs) hold great capacity for differentiating into a variety of cell types, including chondrocytes, and could therefore be utilized as a cartilage cell source in 3D bioprinting. In the present study, we utilize a tabletop stereolithography-based 3D bioprinter for a novel cell-laden cartilage tissue construct fabrication. Printable resin is composed of 10% gelatin methacrylate (GelMA) base, various concentrations of polyethylene glycol diacrylate (PEGDA), biocompatible photoinitiator, and transforming growth factor beta 1 (TGF-β1) embedded nanospheres fabricated via a core-shell electrospraying technique. We find that the addition of PEGDA into GelMA hydrogel greatly improves the printing resolution. Compressive testing shows that modulus of the bioprinted scaffolds proportionally increases with the concentrations of PEGDA, while swelling ratio decreases with the increase of PEGDA concentration. Confocal microscopy images illustrate that the cells and nanospheres are evenly distributed throughout the entire bioprinted construct. Cells grown on 5%/10% (PEGDA/GelMA) hydrogel present the highest cell viability and proliferation rate. The TGF-β1 embedded in nanospheres can keep a sustained release up to 21 d and improve chondrogenic differentiation of encapsulated MSCs. The cell-laden bioprinted cartilage constructs with TGF-β1-containing nanospheres is a promising strategy for cartilage regeneration.

Citation: Sparrow JR, Blonska A, Flynn E, et al. Quantitative fundus autofluorescence in mice: correlation with HPLC quantitation of RPE lipofuscin and measurement of retina outer nuclear layer thickness. Invest Ophthalmol Vis Sci. 2013;54:281254: -282054: . DOI:10.1167 PURPOSE. Our study was conducted to establish procedures and protocols for quantitative autofluorescence (qAF) measurements in mice, and to report changes in qAF, A2E bisretinoid concentration, and outer nuclear layer (ONL) thickness in mice of different genotypes and age.METHODS. Fundus autofluorescence (AF) images (558 lens, 488 nm excitation) were acquired in albino Abca4þ/À , and Abca4 þ/þ mice (ages 2-12 months) with a confocal scanning laser ophthalmoscope (cSLO). Gray levels (GLs) in each image were calibrated to an internal fluorescence reference. The bisretinoid A2E was measured by quantitative high performance liquid chromatography (HPLC). Histometric analysis of ONL thicknesses was performed.RESULTS. The Bland-Altman coefficient of repeatability (95% confidence interval) was 618% for between-session qAF measurements. Mean qAF values increased with age (2-12 months) in all groups of mice. qAF was approximately 2-fold higher in Abca4 À/À mice than in Abca4mice and approximately 20% higher in heterozygous mice. HPLC measurements of the lipofuscin fluorophore A2E also revealed age-associated increases, and the fold difference between Abca4 À/À and wild-type mice was more pronounced (approximately 3-4-fold) than measurable by qAF. Moreover, A2E levels declined after 8 months of age, a change not observed with qAF. The decline in A2E levels in the Abca4 À/À mice corresponded to reduced photoreceptor cell viability as reflected in ONL thinning beginning at 8 months of age.CONCLUSIONS. The qAF method enables measurement of in vivo lipofuscin and the detection of genotype and age-associated differences. The use of this approach has the potential to aid in understanding retinal disease processes and will facilitate preclinical studies.Keywords: Abca4, RPE lipofuscin, quantitative fundus autofluorescence, mouse, bisretinoid F undus autofluorescence (AF) imaging using a confocal scanning laser ophthalmoscope (cSLO) is a noninvasive approach to monitoring the natural autofluorescence of the retina generated from the bisretinoids of lipofuscin in RPE. In early studies of fundus AF in human subjects, quantitation at discrete positions on the fundus was done by noninvasive spectrophotometry. [1][2][3] This work contributed to our understanding of the relationship between RPE lipofuscin accumulation and age, and demonstrated increases in fundus AF in retinal disorders, such as recessive Stargardt disease, 3,4 caused by mutations in the ATP-binding cassette (ABC) transporter ABCA4.5 Conversely, imaging of fundus AF by cSLO records the spatial distribution of fundus AF [6][7][8][9] and is valuable as a means to monitor specific patterns of AF in human retinal diseases, including age related macular degeneration and RP.9-11 Some studies have reported comp...

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Purpose: To examine whether ultra-widefield (UWF) retinal imaging can identify biomarkers for Alzheimer’s disease (AD) and its progression. Methods: Images were taken using a UWF scanning laser ophthalmoscope (Optos P200C AF) to determine phenotypic variations in 59 patients with AD and 48 healthy controls at baseline (BL). All living participants were invited for a follow-up (FU) after 2 years and imaged again (if still able to participate). All participants had blood taken for genotyping at BL. Images were graded for the prevalence of age-related macular degeneration-like pathologies and retinal vascular parameters. Comparison between AD patients and controls was made using the Student t test and the χ² test. Results: Analysis at BL revealed a significantly higher prevalence of a hard drusen phenotype in the periphery of AD patients (14/55; 25.4%) compared to controls (2/48; 4.2%) [χ² = 9.9, df = 4, p = 0.04]. A markedly increased drusen number was observed at the 2-year FU in patients with AD compared to controls. There was a significant increase in venular width gradient at BL (zone C: 8.425 × 10^–3 ± 2.865 × 10^–3 vs. 6.375 × 10^–3 ± 1.532 × 10^–3, p = 0.008; entire image: 8.235 × 10^–3 ± 2.839 × 10^–3 vs. 6.050 × 10^–3 ± 1.414 × 10^–3, p = 0.004) and a significant decrease in arterial fractal dimension in AD at BL (entire image: 1.250 ± 0.086 vs. 1.304 ± 0.089, p = 0.049) with a trend for both at FU. Conclusions: UWF retinal imaging revealed a significant association between AD and peripheral hard drusen formation and changes to the vasculature beyond the posterior pole, at BL and after clinical progression over 2 years, suggesting that monitoring pathological changes in the peripheral retina might become a valuable tool in AD monitoring.

Polar areas are experiencing some of the most rapid impacts of climate change, yet we have a limited understanding of biological vulnerability to multiple stressors. Increased temperature broadly affected early embryo physiology in the naked dragonfish, while ocean acidification interacted synergistically with temperature to decrease survival and alter developmental rate.

TitleAntarctic emerald rockcod have the capacity to compensate for warming when uncoupled from CO2 -acidification. P R I M A R Y R E S E A R C H A R T I C L EAntarctic emerald rockcod have the capacity to compensate for warming when uncoupled from CO 2 -acidification (Egginton & Campbell, 2016;Enzor et al., 2013Enzor et al., , 2017Franklin, Davison, & Seebacher, 2007;Jayasundara, Healy, & Somero, 2013;Seebacher et al., 2005); however, the degree of vulnerability and acclimation capacity may be species-specific (Egginton & Campbell, 2016;Franklin et al., 2007;Jayasundara et al., 2013; Robinson & Davison, 2008a,b;Seebacher et al., 2005). For example, studies of the emerald rockcod,Trematomus bernacchii, a dominant benthic species by biomass in the Ross Sea (Vacchi, La Mesa, & Greco, 2000), have demonstrated impacts of warming across several levels of organization, including limitations in cardiac performance (Jayasundara et al., 2013), sustained elevated metabolic costs (Enzor et al., 2013(Enzor et al., , 2017 & DeVries, 1967), and up to an 85% reduction in growth (Sandersfeld et al., 2015). In comparison, the bald notothen Pagothenia borchgrevinki has exhibited less sensitivity to warming, demonstrating partial compensation for increased metabolic rates (Enzor et al., 2013(Enzor et al., , 2017) and a greater capacity to cope marked by modifications in cardiorespiratory and metabolic adjustments (Franklin et al., 2007; Robinson & Davison, 2008a,b;Seebacher et al., 2005). Differential responses to warming may be explained by varied ecological niches of these species. Trematomus bernacchii are more benthic, ranging from shallow to deeper waters (50-400 m), compared to P. borchgrevinki that live just under the annual sea-ice potentially exposing them to more environmental variability and influencing a greater capacity to acclimate (Eastman, 1993). Although notothen species have showed varying responses to warming alone, the simultaneous addition of elevated CO 2 (i.e., multiple stressor) elicited more similar physiological responses (Enzor et al., 2013(Enzor et al., , 2017Strobel et al., 2012;Strobel, Graeve, et al., 2013;Strobel, Leo, et al., 2013). When exposed to elevated PCO 2 concurrently with warming, both species (Davis et al., 2016). Hyperventilation, while a sufficient buffering mechanism of hypercapnia in fishes, is also energetically expensive (Cameron & Cech, 1970;Dejours, 1981 Although understanding physiological sensitivity to acute and chronic exposures of CO 2 -acidification and elevated temperature is essential to predicting vulnerability to environmental change, often the first response of an organism to environmental change is to alter behavior (Nagelkerken & Munday, 2015). Biotic interactions are strongly driven by abiotic influences such that species may experience "trade-offs" between mounting stress tolerance mecha- The objectives of this study were (i) to examine how acclimation to increased temperature and PCO 2 impacted the physiological performance of juvenile emerald rockcod, T. bern...

When neural retina is disordered, AF from photoreceptor cells can contribute to noninvasive fundus AF images. Hyperautofluorescent puncta in fundus AF images are attributable, in at least some cases, to photoreceptor cell rosettes.