Multiscale embedded printing of engineered human tissue and organ equivalents.

Creating tissue and organ equivalents with intricate architectures and multiscale functional feature sizes is the first step toward the reconstruction of transplantable human tissues and organs. Existing embedded ink writing approaches are limited by achievable feature sizes ranging from hundreds of microns to tens of millimeters, which hinders their ability to accurately duplicate structures found in various human tissues and organs. In this study, a multiscale embedded printing (MSEP) strategy is developed, in which a stimuli-responsive yield-stress fluid is applied to facilitate the printing process. A dynamic layer height control method is developed to print the cornea with a smooth surface on the order of microns, which can effectively overcome the layered morphology in conventional extrusion-based three-dimensional bioprinting methods. Since the support bath is sensitive to temperature change, it can be easily removed after printing by tuning the ambient temperature, which facilitates the fabrication of human eyeballs with optic nerves and aortic heart valves with overhanging leaflets on the order of a few millimeters. The thermosensitivity of the support bath also enables the reconstruction of the full-scale human heart on the order of tens of centimeters by on-demand adding support bath materials during printing. The proposed MSEP demonstrates broader printable functional feature sizes ranging from microns to centimeters, providing a viable and reliable technical solution for tissue and organ printing in the future.

Clinical features, radiological imaging, and treatment strategies of nonmetallic intraorbital foreign bodies: a retrospective analysis.

AIM: To provide comprehensive data on nonmetallic intraorbital foreign bodies (IOFBs) by summarizing and analyzing material types, clinical manifestations, imaging features, and treatment strategies. METHODS: Totally 28 nonmetallic IOFB cases treated at Shengjing Hospital of China Medical University from 2012 to 2020 were retrospectively reviewed. The types of foreign bodies, clinical features, imaging manifestations, and treatment outcomes were analyzed. RESULTS: Among all cases, 67.8% (19/28) of the foreign bodies were organic. The top three entrances were the upper eyelid skin (7/28), lower fornix conjunctiva (6/28), and lower eyelid skin (4/28). In most cases (11/28, 39.3%), foreign bodies remained in the medial orbits. The major clinical manifestations included eyelid redness and swelling (20/28, 71.4%), conjunctival congestion and edema (17/28, 60.7%), and ophthalmoptosis (15/28, 53.6%). Infection was the main complication, which occurred in 57.1% (16/28) of all cases. Computerized tomography (CT) values differed for different foreign bodies and varied in the different periods after injury. The plant- and grease-derived foreign bodies and the surrounding pus cysts showed different signals on magnetic resonance imaging (MRI). The prognosis varied with different foreign body types, surgery timing, and intraoperative management. CONCLUSION: The majority of nonmetallic IOFBs are organic and often remain in the superior, medial, and inferior areas of the orbit. Clinical manifestations vary owing to their different textures. CT and MRI facilitate the identification of foreign body materials. Plant-derived foreign bodies should be completely removed, and surgical treatment is a complicated process.

Quercetin protects against diabetic retinopathy in rats by inducing heme oxygenase-1 expression.

Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions. However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear. In this study, we established a rat model of streptozocin-induced diabetic retinopathy. Seventy-two hours later, the rats were intraperitoneally administered 150 mg/kg quercetin for 16 successive weeks. Quercetin markedly increased the thickness of the retinal cell layer, increased the number of ganglion cells, and decreased the overexpression of the pro-inflammatory factors interleukin-1ß, interleukin-18, interleukin-6 and tumor necrosis factor-α in the retinal tissue as well as the overexpression of high mobility group box-1 and the overactivation of the NLRP3 inflammasome. Furthermore, quercetin inhibited the overexpression of TLR4 and NF-κBp65, reduced the expression of the pro-angiogenic vascular endothelial growth factor and soluble intercellular adhesion molecule-1, and upregulated the neurotrophins brain-derived neurotrophic factor and nerve growth factor. Intraperitoneal injection of the heme oxygenase-1 inhibitor zinc protoporphyrin blocked the protective effect of quercetin. These findings suggest that quercetin exerts therapeutic effects in diabetic retinopathy possibly by inducing heme oxygenase-1 expression. This study was approved by the Animal Ethics Committee of China Medical University, China (approval No. 2016PS229K) on April 8, 2016.

Theoretical model of pediatric orbital trapdoor fractures and provisional personalized 3D printing-assisted surgical solution.

Pediatric orbital trapdoor fractures are common in children and adolescents and usually require emergency surgical intervention. Herein, a personalized 3D printing-assisted approach to surgical treatment is proposed, serving to accurately and effectively repair pediatric orbital trapdoor fractures. We first investigated stress distribution in external force-induced orbital blowout fractures via numerical simulation, determining that maximum stresses on inferior and medial walls exceed those on superior and lateral walls and thus confer higher probability of fracture. We also examined 36 pediatric patients treated for orbital trapdoor fractures between 2014 and 2019 to verify our theoretical construct. Using 3D printing technique, we then created orbital models based on computed tomography (CT) studies of these patients. Absorbable implants were tailor-made, replicating those of 3D-printed models during surgical repairs of fractured orbital bones. As follow-up, we compared CT images and clinical parameters (extraocular movements, diplopia, enophthalmos) before and 12 months after operative procedures. There were only two patients with diplopia and six with enophthalmos >2 mm at 12 months, attesting to the efficacy of our novel 3D printing-assisted strategy.

Serum vaspin levels are positively associated with diabetic retinopathy in patients with type 2 diabetes mellitus.

AIMS/INTRODUCTION: Vaspin is linked to obesity and its metabolic abnormalities. However, the role of vaspin serum levels in diabetic retinopathy (DR) is unknown. In the present study, we investigated the association between serum levels of vaspin and both DR and vision-threatening DR. MATERIALS AND METHODS: This was a cross-sectional single-center observational study from December 2018 to September 2019. We evaluated circulating serum levels of vaspin in 372 participants with type 2 diabetes. DR was screened through detailed ocular examination. DR patients were also divided two groups: vision-threatening DR and non-vision-threatening DR. The relationship between vaspin and DR was investigated by univariate and multivariate logistic regression analyses, and the results are shown as odds ratios with 95% confidence intervals. RESULTS: The vaspin serum levels of 372 patients were obtained, with a median value of 1.50 ng/mL (interquartile range 0.94-2.18 ng/mL). The median age of those patients was 53 years (interquartile range 44-62 years), and 44.4% were women. Patients with DR and VDTR had significantly increased vaspin serum levels (P < 0.001 andP < 0.001). A multivariable regression model found that patients with high levels of vaspin were approximately 1.85-fold (odds ratio for per unit increase 1.85, 95% confidence interval 1.43-2.55; P < 0.001) more likely to experience DR, and 3.76-fold (odds ratio for per unit increase 3.76, 95% confidence interval 2.05-6.55; P < 0.001) more likely to experience VTDR. The predictive value of vaspin was stronger in women than in men. CONCLUSION: Higher vaspin serum levels were associated with an increased risk of DR and VDTR in patients with type 2 diabetes, which showed that vaspin is an important indicator factor for DR.

NLRP3 Blockade Suppresses Pro-Inflammatory and Pro-Angiogenic Cytokine Secretion in Diabetic Retinopathy.

BACKGROUND: Inflammation and angiogenesis are the two dominant mechanisms of diabetic retinopathy (DR), which act more as mutual pathways rather than individual processes. However, the underlying mechanism of their interactions is still unclear. Here, we explored the potential crossing points between these pathways and the targeted therapeutic method in rats with DR. MATERIALS AND METHODS: Sprague-Dawley rats were randomly assigned to four groups: normal control group, streptozocin (STZ)-induced diabetes mellitus (DM) group, DM+shNC (non-specific negative control shRNA) group, and DM+shNLRP3 group. Silencing the NLR family pyrin domain containing 3 (NLRP3) protein was performed by intravitreal injections of NLRP3-targeted shRNA (shNLRP3) for rats in the DM+shNLRP3 group. All the rats' retinas were collected for further morphological examination and pro-inflammatory and pro-angiogenic cytokine detection. Human retinal endothelial cells (HRECs) were also employed to explore the underlying mechanism. RESULTS: NLRP3-targeted shRNA given by intravitreal injection effectively alleviated the retinal histopathological changes in STZ-induced diabetic rats, which reduced the activation of the NLRP3 inflammasome and suppressed the expressions of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and inflammatory cytokines in diabetic rats' retinas. In HRECs, NLRP3 over-expressing plasmid evoked an increase in pro-inflammatory cytokines and VEGF. In addition, YC-1, a HIF-1α inhibitor, could reverse the NLRP3 over-expression-induced VEGF production but not the pro-inflammatory cytokine expressions. CONCLUSION: Our results suggest NLRP3 inflammasome as the potential cross-point between inflammation and pro-angiogenesis in DR and support the effectiveness of NLRP3-targeted shRNA administrated by intravitreal injection in animal models of DR. The protective effect of NLRP3-targeted shRNA may stem from the inhibition of both pro-inflammatory cytokines and HIF-1α/VEGF axis.

MiR-486-3p inhibits the proliferation, migration and invasion of retinoblastoma cells by targeting ECM1.

It has been reported that miR-486-3p expression is decreased in retinoblastoma (RB) tumor tissues, however, its function in RB has been less reported. The present study aimed to explore the regulatory effects of miR-486-3p on RB cells. The expression of miR-486-3p in RB tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, proliferation, apoptosis, migration and invasion ability were determined by cell counting kit-8 (CCK-8) kit, clone formation assay, flow cytometry, scratch assay and transwell, respectively. Targetscan 7.2 and dual-luciferase reporter were used to verify target genes for miR-486-3p. The expressions of apoptosis-related proteins and ECM1 were detected by Western blot. The miR-486-3p expression was decreased in RB tissues and cells. In RB cells, overexpression of miR-486-3p inhibited cell proliferation, migration and invasion, while promoted apoptosis. Moreover, overexpression of miR-486-3p decreased Bcl-2 expression, while increased the expressions of Bax and Cleaved Caspase-3 (C caspase-3). ECM1 was the target gene of miR-486-3p, and miR-486-3p inhibited the expression of ECM1. Furthermore, ECM1 partially reversed the inhibitory effect of miR-486-3p on the proliferation, migration and invasion of RB cells. MiR-486-3p inhibited the proliferation, migration and invasion of RB by down-regulating ECM1.

Targeting heme oxygenase-1 by quercetin ameliorates alcohol-induced acute liver injury via inhibiting NLRP3 inflammasome activation.

Alcoholic hepatitis (AH) is characterized by inflammation and necrosis of liver tissue caused by excessive alcohol consumption and it even causes organ failure sometimes, in which oxidative stress plays an important role. Quercetin is a bioactive flavonoid in the class of polyphenols with a free-radical scavenging ability and anti-inflammatory activity. Recently it has aroused great interest because of its potential benefits in the prevention and intervention of cancer, cardiovascular abnormalities, neurodegenerative diseases, metabolic disorders and liver fibrosis. However, its role in alcoholic liver injury is still unclear and needs to be elucidated. Through database analysis and serum measurements, we found that there was a decline in the level of heme oxygenase-1 (HO-1) in patients with acute alcoholic hepatitis compared to healthy controls. Quercetin could elevate the expression of nuclear factor E2-related factor 2(Nrf2)/HO-1 and ameliorate ethanol-induced acute liver injury in rats. Moreover, this protective effect of quercetin could be diminished when combined with the HO-1 inhibitor ZnppIX which demonstrated a critical role of HO-1 in quercetin's hepatoprotection. The underlying mechanism of quercetin's benefit on the liver may be explained by its anti-oxidant properties and inhibitory effect on the ROS/NF-κB/NLRP3 inflammasome/IL-1ß and IL-18 pathway by inducing HO-1. Meanwhile, quercetin also upregulated the anti-inflammatory factor IL-10, while it was found uncorrelated with HO-1 expression. In conclusion, quercetin can preserve the function of the liver in acute alcoholic injury by upregulating the expression of IL-10 and HO-1 and thus inhibiting NLRP3 inflammasome activation and inflammatory factor secretion. In other words, quercetin looks promising as an alternative treatment and HO-1 may be a potential target in the crosstalk of inflammation and oxidative stress in alcoholic liver damage.

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

AIM: To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. METHODS: In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. RESULTS: At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo (P<0.01). CONCLUSION: Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer TBUT.