Coaxial 3D printing of hierarchical structured hydrogel scaffolds for on-demand repair of spinal cord injury.

After spinal cord injury (SCI), endogenous neural stem cells (NSCs) near the damaged site are activated, but few NSCs migrate to the injury epicenter and differentiate into neurons because of the harsh microenvironment. It has demonstrated that implantation of hydrogel scaffold loaded with multiple cues can enhance the function of endogenous NSCs. However, programming different cues on request remains a great challenge. Herein, a time-programmed linear hierarchical structure scaffold is developed for spinal cord injury recovery. The scaffold is obtained through coaxial 3D printing by encapsulating a dual-network hydrogel (composed of hyaluronic acid derivatives and N-cadherin modified sodium alginate, inner layer) into a temperature responsive gelatin/cellulose nanofiber hydrogel (Gel/CNF, outer layer). The reactive species scavenger, metalloporphyrin, loaded in the outer layer is released rapidly by the degradation of Gel/CNF, inhibiting the initial oxidative stress at lesion site to protect endogenous NSCs; while the inner hydrogel with appropriate mechanical support, linear topology structure and bioactive cues facilitates the migration and neuronal differentiation of NSCs at the later stage of SCI treatment, thereby promoting motor functional restorations in SCI rats. This study offers an innovative strategy for fabrication of multifunctional nerve regeneration scaffold, which has potential for clinical treatment of SCI. STATEMENT OF SIGNIFICANCE: Two major challenges facing the recovery from spinal cord injury (SCI) are the low viability of endogenous neural stem cells (NSCs) within the damaged microenvironment, as well as the difficulty of neuronal regeneration at the injured site. To address these issues, a spinal cord-like coaxial scaffold was fabricated with free radical scavenging agent metalloporphyrin Mn (III) tetrakis (4-benzoic acid) porphyrin and chemokine N-cadherin. The scaffold was constructed by 3D bioprinting for time-programmed protection and modulation of NSCs to effectively repair SCI. This 3D coaxially bioprinted biomimetic construct enables multi-factor on-demand repair and may be a promising therapeutic strategy for SCI.

Intradural disc herniation at the L2/3 level: a case report and literature review.

BACKGROUND: Intradural lumbar disc herniation (ILDH) is special type of lumbar disc herniation in which the lumbar nucleus pulposus prolapses and enters the dura mater. ILDHs comprise 0.04-0.33% of all herniated discs. In most cases, the diagnosis could not be confirmed preoperatively by identifying the typical features of ILDH in radiological evaluation. In the current report, we present a case of ILDH at lumbar 2/3 level and discuss the clinical presentations, typical imaging features, treatments, and outcomes. CASE DESCRIPTION: We describe a rare case of ILDH. The patient was a 65-year-old man with pain in waist and back, and with bilateral radiating pain of lower extremities and fatigue for more than 2 weeks. Magnetic resonance imaging (MRI) revealed a large round, low-density mass at lumbar 2/3, which was easily mimicked as an intradural spinal tumor lesion. While enhanced MRI showed the typical rim enhancement sign and "Hawk beak" sign. Due to progressive decrease in muscle strength in both lower limbs, posterior microscopically assisted laminectomy, dural incision of the lumbar 2/3 was performed. Pathological examination revealed degenerated fibrous connective tissue and cartilage tissue. The patient's lower back pain and radiating pain and numbness of both legs improved remarkably postoperatively, and he became asymptomatic at 3 months and 1-year postoperatively. CONCLUSIONS: ILDH is a rare intervertebral disc herniation in clinical practice. The pathogenesis of ILDH may be related to aseptic inflammatory edema, closely fixing of ventral dura and the posterior longitudinal ligament, repeated mechanical action and chemical corrosion. Typical rim enhancement sign, "Hawk beak" sign and "Y" sign are important features of MRI in diagnosing ILDH, and intraspinal gas is also helpful in computed tomography (CT) diagnosis of ILDH. Prompt microscopically assisted laminectomy, dura mater incision to remove the intradural disc, pedicle screw fixation regardless of fusion, surgical results are usually favorable. We also reviewed the literature and discussed the epidemiology, potential pathogenesis, diagnosis, treatment and poor prognostic factors of ILDH.

Inhibitory Effect of MicroRNA-107 on Osteosarcoma Malignancy Through Regulation of Wnt/ß-catenin Signaling in Vitro.

We showed that miR-107 expression was decreased in osteosarcoma (OS) tissues and cell lines. miR-107 mimic significantly decreased OS cell proliferation and inhibited invasion and migration of OS cells. Inhibition of miR-107 expression notably promoted proliferation, invasion and migration of OS cells. In addition, miR-107 mimic inhibited EMT biomarkers and significantly increased apoptosis. miR-107 mimic significantly decreased the protein expression of ß-catenin, Cyclin D1, and c-Myc, whereas increased GSK-3ß protein expression. miR-107 mimic markedly reduced the luciferase activity of 3'UTR of ß-catenin. Overexpression of ß-catenin inhibited miR-107 mimic-induced decrease of cell proliferation, invasion and migration ability, and increase of apoptosis.

[Comparison of inter- and intra-observer reliability between GATA and SMU classification systems for spinal tuberculosis].

OBJECTIVE: To compare the inter- and intra-observer reliability of the GATA and SMU classification systems for spinal tuberculosis and assess the clinical value of SMU classification. METHODS: One hundred patients with spinal tuberculosis treated in our hospital from January 2004 to December 2011 were randomly selected for analysis, including 54 males and 46 females with a mean age of 45 years (range, 16-68 years). All the patients had X-ray, CT and MRI examinations. Five observers experienced in spinal tuberculosis independently assigned the classification using the GATA and SMU classification systems, and the assignment was repeated 3 months later to test its reproducibility. Kappa value was used to determine the intra- and inter-observer reliability. RESULTS: For GATA and SMU classification systems, the inter-observer percentage of agreement averaged (59.9∓4.84)% (κ=0.412∓0.058) and (81.6∓6.06)% (κ=0.753∓0.068), and the intra-observer percentage of agreement was (75.6∓5.27)% (κ=0.624∓0.078) and (89.8∓2.28)% (κ=0.862∓0.037), respectively. CONCLUSION: The SMU classification system of spinal tuberculosis has a higher inter-observer and intra-observer reliability than the GATA classification system, but its clinical value needs to be further tested in future clinical trials.

[Jiawei shentong zhuyu decoction prevented the occurrence of failed back surgery syndrome and its effect on serum TNF-alpha a clinical study].

OBJECTIVE: To explore the clinical roles of Jiawei Shentong Zhuyu Decoction (JSZD) in preventing the occurrence of failed back surgery syndrome (FBSS), and to observe its effect on serum tumor necrosis factor-alpha (TNF-alpha). METHODS: Totally 100 patients prepared for surgical operation due to lumbar intervertebral disc herniation were randomly assigned to the treatment group and the control group according to random number table, 50 cases in each group. Patients in the treatment group additionally took JSZD, one dose per day, taken in two portions, once in the morning and once in the evening. Those in the control group took Celecoxib Capsule (200 mg each time, once per day) and Mecobalamin Tablet (0.5 mg each time, 3 times per day). They only took Mecobalamin Tablet from the 11th day. All patients were treated for 30 days. Japanese Orthopaedic Association (JOA) score was performed before treatment, at week 1, after treatment, at 6 months of followed-ups, and at 12 months of followed-ups. And the levels of TNF-alpha in the peripheral blood were observed before treatment and at one month after treatment. RESULTS: Totally 93 patients completed the followed-up study. The JOA scores were improved after treatment, at 6 and 12 months of followed-ups (P < 0.05, P < 0.01). The JOA score at 6 months of followed-ups was superior in the treatment group to that of the control group (P < 0.05). Five patients (accounting for 10.6%) suffered from FBSS in the treatment group, while 9 (accounting for 19.6%) suffered from FBSS in the control group. The treatment group was superior to the control group (P < 0.05). The TNFalpha level was improved after treatment in the two groups. Of them, the improvement of TNF-alpha in the treatment group was better than that of the control group (P < 0.05). CONCLUSION: The application of JSZD was effective for preventing the occurrence of FBSS, and improved the serum TNF-alpha level.