Moderate white light exposure enhanced spatial memory retrieval by activating a central amygdala-involved circuit in mice.

Light exposure can profoundly affect neurological functions and behaviors. Here, we show that short-term exposure to moderate (400 lux) white light during Y-maze test promoted spatial memory retrieval and induced only mild anxiety in mice. This beneficial effect involves the activation of a circuit including neurons in the central amygdala (CeA), locus coeruleus (LC), and dentate gyrus (DG). Specifically, moderate light activated corticotropin-releasing hormone (CRH) positive (+) CeA neurons and induced the release of corticotropin-releasing factor (CRF) from their axon terminals ending in the LC. CRF then activated tyrosine hydroxylase-expressing LC neurons, which send projections to DG and release norepinephrine (NE). NE activated ß-adrenergic receptors on CaMKIIα-expressing DG neurons, ultimately promoting spatial memory retrieval. Our study thus demonstrated a specific light scheme that can promote spatial memory without excessive stress, and unraveled the underlying CeA-LC-DG circuit and associated neurochemical mechanisms.

Symplectic superposition solutions for free in-plane vibration of orthotropic rectangular plates with general boundary conditions.

This work reports new analytic free in-plane vibration solutions for orthotropic non-Lévy-type rectangular plates, i.e., those without two opposite edges simply supported, by the symplectic superposition method (SSM), which has never been applied to in-plane elasticity problems in any existing works. Such analytic solutions are not accessible through conventional analytic methods as seeking analytic solutions that meet both the governing partial differential equations and various non-Lévy-type boundary conditions is an acknowledged challenge in mechanical analysis of plates. The clamped and free plates are considered as two most representative cases of non-Lévy-type plates. The SSM is implemented in the Hamiltonian system-based symplectic space, where the separation of variables and the symplectic eigen expansion prove to be well-grounded. These two mathematical treatments are adopted to first gain the analytic solutions of two elementary problems. The final analytic free in-plane vibration solutions are obtained by superposition of the two elementary problems. Comprehensive new natural frequencies and vibration modes are studied and validated by reference solutions from the finite element method or other approaches. The rigorous solution procedure, fast convergence, and highly accurate results render the present framework capable of serving as benchmarks for future comparison and applicable to analytic investigation of more plate problems.

Is Early Controlled Motion and Weightbearing Recommended for Nonoperatively Treated Acute Achilles Tendon Rupture? A Systematic Review and Meta-analysis.

BACKGROUND: There is disagreement as to whether early controlled motion and weightbearing confer a beneficial effect for nonoperatively treated acute Achilles tendon rupture (ATR) compared with immobilization and late weightbearing. PURPOSE: To conduct a meta-analysis of randomized controlled trials (RCTs) to determine whether early controlled motion and weightbearing results in different outcomes compared with immobilization and late weightbearing for nonoperatively treated patients with acute ATR. STUDY DESIGN: Systematic review; Level of evidence, 1. METHODS: We conducted a search in the PubMed, Web of Science, and EMBASE databases for relevant RCTs in humans from January 1981 to August 2020. The primary outcome was the Achilles Tendon Total Rupture Score (ATRS) at 1-year follow-up. The secondary outcomes were the rerupture rate, return to sports activity and work, and the heel-rise work (limb symmetry index [LSI]). Study quality was assessed using the Cochrane Collaboration risk of bias tool. RESULTS: Included were 7 RCTs involving 424 participants (n = 215 treated with early controlled motion and weightbearing [early group], n = 209 treated with immobilization and late weightbearing [late group]). The quality assessment indicated a low risk of bias in all included RCTs. There was no difference between the early and late groups regarding the ATRS (mean difference [MD], -0.220; 95% CI, -4.489 to 4.049; P = .920). Likewise, we found no difference between the 2 groups in terms of the rerupture rate (odds ratio [OR], 1.107; 95% CI, 0.552 to 2.219; P = .775), the number of patients who returned to sports (OR, 0.766; 95% CI, 0.438 to 1.341; P = .351) and returned to work (OR, 0.706; 95% CI, 0.397 to 1.253; P = .234), the time to return to work (MD, -2.802 days; 95% CI, -6.525 to 0.921 days; P = .140), or the heel-rise work LSI (MD, -0.135; 95% CI, -6.243 to 5.973; P = .965). CONCLUSION: No significant differences were found between early controlled motion and weightbearing compared with immobilization and late weightbearing regarding the ATRS, the rerupture rate, return to sports activity and work, and the heel-rise work in nonoperatively treated patients with acute ATR.

Analysis of the main soft tissue stress associated with flexible flatfoot deformity: a finite element study.

A better understanding of soft tissue stress and its role in supporting the medial longitudinal arch in flexible flatfoot could help to guide the clinical treatment. In this study, a 3-Dimensional finite element (FE) foot model was reconstructed to measure the stress of the soft tissue, and its variation in different scenarios related to flexible flatfoot. All bones, cartilages, ligaments and related tendons around the ankle, and fat pad were included in the finite element model. The equivalent stress on the articular surface of the joints in the medial longitudinal arch and the maximum principal stress of the ligaments around the ankle were obtained. The results show that the plantar fascia (PF) is the main tissue in maintaining the medial longitudinal arch. The equivalent stress of all the joints in the medial longitudinal arch increases when the PF attenuation and the talonavicular joint increases, while other joints decreases when all the three tissue attenuation. Moreover, the maximum principal stress variation of calcaneofibular ligament is largest when the PF attenuation and the tibionavicular ligament and posterior tibiotalar ligament are largest when the posterior tibial tendon (PTT) attenuation. The maximum principal stress variation of tibionavicular ligament and posterior tibiotalar ligament are even larger when all the three tissue attenuation. These findings support that the PF is the main factor in maintaining the medial longitudinal arch. The medial longitudinal arch collapse mainly affects the talonavicular joint and the calcaneofibular ligament, the tibionavicular ligament and the posterior tibiotalar ligament. This approach could help to improve the understanding of adult-acquired flatfoot deformity (AAFD).

Effect of soft inflatable orthosis on the medial longitudinal arch in patients with flexible flatfoot deformity.

BACKGROUND: Orthoses can stabilize the foot and restore the medial longitudinal arch for symptomatic flexible flatfoot. However, the effectiveness of orthoses remains controversial. The purpose of this study was to evaluate effectiveness of a customized soft inflatable orthosis on the medial longitudinal arch of flexible flatfoot patients under load. METHODS: We obtained CT scans of the feet of 14 healthy volunteers and 14 patients with flexible flatfoot under non- and simulated weight-bearing conditions. Then CT scans under the same conditions were taken for patients with flexible flatfoot equipped with soft inflatable orthosis. Three-dimensional models of the medial longitudinal arch and hindfoot were constructed from CT images. The three-dimensional mobility of the medial longitudinal arch joints under load was compared between patients with flexible flatfoot equipped with soft inflatable orthosis or not. FINDINGS: From non- to simulated weight-bearing condition, the eversion and dorsiflexion of the talocalcaneal joint, the eversion of the talonavicular joint, the abduction and dorsiflexion of the cuneonavicular joint, and the dorsiflexion of the first tarsometatarsal joint were significantly larger in patients with flexible flatfoot than healthy volunteers. The customized soft inflatable orthosis could reduce the eversion of the talonavicular joint and the eversion and dorsiflexion of the talocalcaneal joint. INTERPRETATION: The soft inflatable orthosis is effective to improve medial longitudinal arch height and reduce excessive mobility of joints for flexible flatfoot deformity. The results of this study could provide evidence for the optimal orthosis design to treat flexible flatfoot in the future.

Automatic microaneurysm detection in fundus image based on local cross-section transformation and multi-feature fusion.

BACKGROUND AND OBJECTIVE: Retinal microaneurysm (MA) is one of the earliest clinical signs of diabetic retinopathy(DR). Its detection is essential for controlling DR and preventing vision loss. However, the spatial scale of MA is extremely small and the contrast to surrounding background is subtle, which make MA detection challenging. The purpose of this work is to automatically detect MAs from fundus images. METHODS: Our MA detector involves two stages: MA candidate extraction and classification. In MA candidate extraction stage, local minimum region extraction and block filtering are used to exploit the regions where MA may exist. In this way, most of irrelavent background regions are discarded , which subsequently facilitates the training of MA classifier. In the second stage, multiple features are extracted to train the MA classifier. To distinguish MA from vascular regions, we propose a series of descriptors according to the cross-section profile of MA. Specially, as MAs are small and their contrast to surroundings is subtle, we propose local cross-section transformation (LCT) to amplify the difference between the MA and confusing structures. Finally, an under-sampling boosting-based classifier (RUSBoost) is trained to determine whether the candidate is an MA. RESULTS: The proposed method is evaluated on three public available databases i.e. e-ophtha-MA, DiaretDB1 and ROC training set. It achieves high sensitivities for low false positive rates on the three databases. Using the FROC metric, the final scores are 0.516, 0.402 and 0.293 respectively, which are comparable to existing state-of-the-art methods. CONCLUSIONS: The proposed local cross-section transformation enhances the discrimination of descriptors by amplifying difference between MAs and confusing structures, which facilitates the classification and improves the detection performances. With the powerful descriptors, our method achieves state-of-the-art performances on three public datasets consistently.

Proximal versus distal adductor canal blocks for total knee arthroplasty: A protocol for randomized controlled trial.

BACKGROUND: Currently, there remains a paucity of literature about the efficiency of proximal adductor canal block (PACB) versus distal adductor canal block (DACB) for pain management after total knee arthroplasty (TKA). The purpose of this study is to perform a randomized controlled trial to compare the efficiency of PACB versus DACB for early postoperative pain treatment after TKA. METHODS: This study is a 2-arm, parallel-group, randomized controlled trial that is conducted at a single university hospital in China. Subjects presenting for unilateral TKA are randomized in a 1:1 ratio to either a PACB or DACB group. The primary outcome of this noninferiority study is opioid consumption within the first 24 hours following surgery. Secondary outcomes include quadriceps strength, pain scores, distance ambulated, and patient satisfaction. Continuous variables are compared using Student t test. RESULTS: This clinical trial is expected to provide evidence of whether the PACB and DACB provide similar analgesia after TKA. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5440).

Correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction.

BACKGROUND: The purpose of this study was to evaluate correlation between three-dimensional medial longitudinal arch joint complex mobility and medial arch angle in stage II posterior tibial tendon dysfunction flatfoot under loading. METHODS: CT scans of 15 healthy feet and 15 feet with stage II posterior tibial tendon dysfunction flatfoot were taken both in non- and simulated weight-bearing condition. The CT images of the hindfoot and medial longitudinal arch bones were reconstructed into three-dimensional models with Mimics and Geomagic reverse engineering software. The three-dimensional complex mobility of each joint in the medial longitudinal arch and their correlation with the medial arch angle change were calculated. RESULTS: From non- to simulated weight-bearing condition, the medial arch angle change and the medial longitudinal arch joints mobility were significant larger in stage II posterior tibial tendon dysfunction flatfoot (p<0.05). The eversion of the talocalcaneal joint, the proximal translation of the calcaneus relative to the talus, the dorsiflexion of the talonavicular joint, the dorsiflexion and abduction of the medial cuneonavicular joint, and the lateral translation of the medial cuneiform relative to the navicular, and the dorsiflexion of the first tarsometatarsal joint were all significantly correlated to the medial arch angle change in stage II posterior tibial tendon dysfunction flatfoot (all r>0.5, p<0.05). CONCLUSIONS: There is increased mobility in the medial longitudinal arch joints in stage II posterior tibial tendon dysfunction flatfoot and the medial arch angle change under loading causes displacement not only at hindfoot joints but also involve midfoot and forefoot joint.

Is Platelet-rich Plasma Injection Effective for Chronic Achilles Tendinopathy? A Meta-analysis.

BACKGROUND: Chronic Achilles tendinopathy is common in the general population, and platelet-rich plasma (PRP) is seeing increased use to treat this problem. However, studies disagree as to whether PRP confers a beneficial effect for chronic Achilles tendinopathy, and no one to our knowledge has pooled the available randomized trials in a formal meta-analysis to try to reconcile those differences. QUESTIONS/PURPOSES: In the setting of a systematic review and meta-analysis of randomized controlled trials (RCTs), we asked: Does PRP plus eccentric strength training result in (1) greater improvements in Victorian Institute of Sports Assessment-Achilles (VISA-A) scores; (2) differences in tendon thickness; or (3) differences in color Doppler activity compared with placebo (saline) injections plus eccentric strength training in patients with chronic Achilles tendinopathy? METHODS: A search of peer-reviewed articles was conducted to identify all RCTs using PRP injection with eccentric training for chronic Achilles tendinopathy in the electronic databases of PubMed, Web of Science (SCI-E/SSCI/A&HCI), and EMBASE from January 1981 to August 2017. Results were limited to human RCTs and published in all languages. Two reviewers assessed study quality using the Cochrane Collaboration risk-of-bias tool. All the included studies had low risk of bias. The primary endpoint was improvement in the VISA-A score, which ranges from 0 to 100 points, with higher scores representing increased activity and less pain; we considered the minimum clinically important difference on the VISA-A to be 12 points. Secondary outcomes were tendon thickness change (with a thicker tendon representing more severe disease), color Doppler activity (with more activity representing a poorer result), and other functional measures (such as pain and return to sports activity). Four RCTs involving 170 participants were eligible and included 85 participants treated with PRP injection and eccentric training and 85 treated with saline injection and eccentric training. The patients in both PRP and placebo (saline) groups seemed comparable at baseline. We assessed for publication bias using a funnel plot and saw no evidence of publication bias. Based on previous studies, we had 80% power to detect a 12-point difference on the VISA-A score with the available sample size in each group. RESULTS: With the numbers available, there was no difference between the PRP and saline groups regarding the primary outcome (VISA-A score: mean difference [MD], 5.3; 95% confidence interval [CI], -0.7 to 11.3; p = 0.085). Likewise, we found no difference between the PRP and saline groups in terms of our secondary outcomes of tendon thickness change (MD, 0.2 mm; 95% CI, 0.6-1.0 mm; p = 0.663) and color Doppler activity (MD, 0.1; 95% CI, -0.7 to 0.4; p = 0.695). CONCLUSIONS: PRP injection with eccentric training did not improve VISA-A scores, reduce tendon thickness, or reduce color Doppler activity in patients with chronic Achilles tendinopathy compared with saline injection. Larger randomized trials are needed to confirm these results, but until or unless a clear benefit has been demonstrated in favor of the new treatment, we cannot recommend it for general use. LEVEL OF EVIDENCE: Level I, therapeutic study.

Cdc42 Is Essential for Both Articular Cartilage Degeneration and Subchondral Bone Deterioration in Experimental Osteoarthritis.

Cdc42, a member of Rho family small guanosine triphosphatases (GTPases), is critical for cartilage development. We investigated the roles of Cdc42 in osteoarthritis and explored the potential mechanism underlying Cdc42-mediated articular cartilage degeneration and subchondral bone deterioration. Cdc42 is highly expressed in both articular cartilage and subchondral bone in a mouse osteoarthritis model with surgical destabilization of the medial meniscus (DMM) in the knee joints. Specifically, genetic disruption of Cdc42, knockdown of Cdc42 expression, or inhibition of Cdc42 activity robustly attenuates the DMM-induced destruction, hypertrophy, high expression of matrix metallopeptidase-13 and collagen X, and activation of Stat3 in articular cartilages. Notably, genetic disruption of Cdc42, knockdown of Cdc42 expression or inhibition of Cdc42 activity significantly restored the increased numbers of mesenchymal stem cells, osteoprogenitors, osteoblasts, osteoclasts, and neovascularized vessels, the increased bone mass, and the activated Erk1/2, Smad1/5 and Smad2 in subchondral bone of DMM-operated mice. Mechanistically, Cdc42 mediates interleukin-1ß-induced interleukin-6 production and subsequent Jak/Stat3 activation to regulate chondrocytic inflammation, and also lies upstream of Erk/Smads to regulate subchondral bone remodeling during transform growth factor-ß1 signaling. Cdc42 is apparently required for both articular cartilage degeneration and subchondral bone deterioration of osteoarthritis, thus, interventions targeting Cdc42 have potential in osteoarthritic therapy. © 2018 American Society for Bone and Mineral Research.

Clinical significance of microRNA-130b in osteosarcoma and in cell growth and invasion.

OBJECTIVE: To investigate clinical significance of microRNA-130b (miR-130b) in osteosarcoma and its role in cell growth and invasion. METHODS: miR-130b expression was detected in 68 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues by qRT-PCR. The expression of miR-130b was altered by corresponding vectors in osteosarcoma cells, and then Western blot was used to detect the expression of PPARγ. BrdU cell proliferation and Transwell assays were performed to determine cell proliferation and invasion. RESULTS: The expression of miR-130b in osteosarcoma tissues was significantly higher than that in normal tumor-adjacent tissues. Its expression in patients with metastasis was significantly higher than that in those without metastases. miR-130b expression in tumor tissues was significantly associated with tumor size, clinical stage and distant metastasis. And its expression was significantly correlated with overall survival and disease free survival. miR-130b overexpression obviously repressed the expression of PPARγ, and resulted in significant increase of Saos-2 cell proliferation and invasion. On the contrast, repressing miR-130b expression with its inhibitor significantly increased PPARγ expression, and inhibited MG-63 cell proliferation and invasion. CONCLUSIONS: The high-expression of miR-130b is correlated with the adverse clinicopathological features and poor prognosis in osteosarcoma. miR-130b may regulate proliferation and invasion of osteosarcoma cells by targeting PPARγ, suggesting miR-130b may play a key role in the progression of osteosarcoma.

Anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in the treatment of multilevel cervical spondylotic myelopathy: systematic review and a meta-analysis.

BACKGROUND: To date, the decision to treat multilevel cervical spondylotic myelopathy (CSM) with anterior cervical discectomy and fusion (ACDF) or anterior cervical corpectomy and fusion (ACCF) remains controversial. Therefore, we conducted a meta-analysis to quantitatively determine the efficacy of ACDF and ACCF in the treatment of multilevel CSM. METHODS: We searched several databases for related research articles published in English or Chinese. We extracted and assessed the data independently. We determined the pooled data, data heterogeneity, and overall effect, respectively. RESULTS: We identified 15 eligible studies with 1,368 patients. We found that blood loss and numbers of complications during surgery in ACDF were significantly less that in ACCF; however, other clinical outcomes, such as operation time, bone fusion failure, post Japanese Orthopedic Association scores, recovery rates, and visual analog scale scores between ACDF and ACCF with multilevel CSM were not significantly different. CONCLUSION: Our results strongly suggest that surgical treatments of multilevel CSM are similar in terms of most clinical outcomes using ACDF or ACCF.

miR-26b inhibits proliferation, migration, invasion and apoptosis induction via the downregulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 driven glycolysis in osteosarcoma cells.

MicroRNAs (miRNAs) are differentially expressed and play crucial roles in cancer development and progression. Elevated glycolysis provides survival advantage and metastatic phenotype. Emerging evidence indicates that glycolysis in cancers can be regulated by miRNAs. In the present study, the role of miR-26b in the proliferation, invasion and glycolytic phenotype of osteosarcoma (OS) cells was investigated. miR-26b was reported to be downregulated in OS tissues, however, the effect of miR-26b on OS has not been distinctly evaluated. The present study therefore investigated the miR-26b sensitivity mechanism in OS. To determine the role of miR-26, we reinstated its expression in the U2OS OS cell line through transfection with miR-26b mimics and examined the effects on cell proliferation, migration, invasion, cell cycle progression and glycolytic parameters. The computational prediction tool was employed to identify the molecular target of miR-26b and was confirmed experimentally. Restoration of miR-26b expression inhibited cell proliferation, migration and invasion, arrested cell cycle progression, and induced cell apoptosis accompanied by the downregulation of glycolytic phenotype. Moreover, the binding site for miR-26b was predicted in the 3'UTR of gene 6-phosphofructo-2-kinase/fructose­2,6-bisphosphatase-3 (PFKFB3), suggesting a role for miR-26b in metabolic alteration in OS cells. Further studies showed that overexpression of miR-26b repressed PFKFB3 mRNA and protein levels followed by modulation of the expression of glycolytic components (LDHA, GLUT-1) and markers of invasion and cell cycle such as MMP-9, MMP-2, cyclin D1 and p27. Collectively, the data suggested the tumor suppressive role of miR-26b which functions by targeting the glycolytic metabolism in OS cells, and providing a possible therapeutic strategy for OS patients by targeting miRNA expression.

[Analyses of segment motor function in patients with degenerative lumbar disease on the treatment of WavefleX dynamic stabilization system].

OBJECTIVE: To explore the changes of range-of-motion (ROM) in patients with degenerative lumbar disease on the treatment of WavefleX dynamic stabilization system and examine the postoperative lumbar regularity and tendency of ROM. METHODS: Nine patients with degenerative lumbar disease on the treatment of WavefleX dynamic stabilization system were followed up with respect to ROMs at 5 timepoints within 12 months. Records of ROM were made for instrumented segments, adjacent segments and total lumbar. RESULTS: Compared with preoperation, ROMs in non-fusional segments with WavefleX dynamic stabilization system decreased statistical significantly (P < 0.05 or P < 0.01) at different timepoints; ROMs in adjacent segments increased at some levels without wide statistical significance. The exception was single L3/4 at Month 12 (P < 0.05) versus control group simultaneously at the levels of L3/4, L4/5 and L5/S1, ROMs decreased at Months 6 and 12 with wide statistical significance (P < 0.05 or P < 0.01). ROMs in total lumbar had statistical significant decrease (P < 0.01) in both group of non-fusional segments and hybrid group of non-fusion and fusion. The trends of continuous augments were observed during follow-ups. Statistically significant augments were also acquired at 4 timepoints as compared to control group (P < 0.01). CONCLUSION: The treatment of degenerative lumbar diseases with WavefleX dynamic stabilization system may limit excessive extension/inflexion and preserve some motor functions. Moreover, it can sustain physiological lordosis, decrease and transfer disc load in adjacent segments to prevent early degeneration of adjacent segment. Trends of motor function augment in total lumbar need to be confirmed during future long-term follow-ups.

Polymeric immunoglobulin receptor expression is correlated with poor prognosis in patients with osteosarcoma.

The prognosis of patients with osteosarcoma with distant metastasis and local recurrence remains poor. Increased expression of polymeric immunoglobulin receptor (pIgR) in tumor tissue has been detected in various types of cancer. However, the clinical significance of pIgR in osteosarcoma has yet to be elucidated. The present study aimed to investigate the prognostic value of pIgR in patients with osteosarcoma following surgical resection. pIgR expression was assessed using quantitative polymerase chain reaction analysis in cryopreserved osteosarcoma tissues from 22 patients, as well as using immunohistochemistry in paraffin-embedded osteosarcoma tissues from 136 patients. The association between pIgR expression, clinicopathological factors and long-term prognosis was retrospectively examined in these 136 patients. The prognostic significance of negative or positive pIgR expression in osteosarcoma was assessed using Kaplan-Meier survival analysis and log-rank tests. Univariate analysis indicated that patients with positive pIgR osteosarcoma tissue expression had a significantly worse overall survival (OS) compared with patients with negative pIgR osteosarcoma expression. Multivariate analysis revealed that positive pIgR expression in osteosarcoma tissues was an independent prognostic factor for OS following surgical resection (P<0.001). Furthermore, positive pIgR expression was significantly associated with poor prognosis in patients with osteosarcoma. These findings indicate that pIgR may be a novel predictor for poor prognosis in patients with osteosarcoma following surgical resection.

Injectable silk fibroin/polyurethane composite hydrogel for nucleus pulposus replacement.

In degenerative disc disease, an injectable hydrogel can fill a degenerate area completely, reduce the risk of implant migration and subsequent loss of height of the intervertebral disc, and minimise surgical defects. Here, we propose a method of preparing an injectable silk fibroin/polyurethane (SF/PU) composite hydrogel by chemical cross-linking under physiological conditions. Mechanical testing was used to determine the mechanical strength of the hydrogel. The impact of hydrogel height on the biomechanical properties was discussed to estimate the working capacity of the hydrogel for further clinical application. Rheological properties were also examined to assess the practical ability of the hydrogel for clinical application. Hydrogel injection and cell assessment is also of interest for clinical application. An SF/PU composite hydrogel can be injected through a small incision. A cell proliferation assay using bone marrow stromal cells showed positive cell viability and increased proliferation over a seven-day period in culture. Importantly, the hydrogel can be monitored in real-time using X-ray fluoroscopy during and after surgery according to the results of X-ray fluoroscopy examination, and shows good visibility based on X-ray assays. In particular, the hydrogel offers the clinically important advantage of visibility in CT and T2-weighted magnetic resonance imaging. Based on the results of the current study, the SF/AU composite hydrogel may offer several advantages for future application in nucleus pulposus replacement.