Carbene-mediated gelatin and hyaluronic acid hydrogel paints with ultra adhesive ability for arthroscopic cartilage repair.

In articular cartilage defect, particularly in arthroscopy, regenerative hydrogels are urgently needed. It should be able to firmly adhere to the cartilage tissue and maintain sufficient mechanical strength to withstand approximately 10 kPa of arthroscopic hydraulic flushing. In this study, we report a carbene-mediated ultra adhesive hybrid hydrogel paints for arthroscopic cartilage repair, which combined the photo initiation of double crosslinking system with the addition of diatomite, as a further reinforcing agent and biological inorganic substances. The double network consisting of ultraviolet initiated polymerization of hyaluronic acid methacrylate (HAMA) and carbene insertion chemistry of diazirine-grafted gelatin (GelDA) formed an ultra-strong adhesive hydrogel paint (H2G5DE). Diatomite helped the H2G5DE hydrogel paint firmly adhere to the cartilage defect, withstanding nearly 100 kPa of hydraulic pressure, almost 10 times that in clinical arthroscopy. Furthermore, the H2G5DE hydrogel supported cell growth, proliferation, and migration, thus successfully repairing cartilage defects. Overall, this study demonstrates a proof-of-concept of ultra-adhesive polysaccharide hydrogel paints, which can firmly adhere to the articular cartilage defects, can resist continuous hydraulic pressure, can promote effective cartilage regeneration, and is very suitable for minimally invasive arthroscopy.

Relationship between tool-like receptor 4 gene polymorphism and the susceptibility to pulmonary tuberculosis.

OBJECTIVE: To evaluate the susceptibility of pulmonary tuberculosis based on the single nucleotide polymorphism (SNP) of Toll like receptor 4 (TLR4) gene. METHODS: We searched PubMed, Web of science, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases using mesh words: "tuberculosis", "pulmonary", "TLR4", "SNP", "Toll like receptor 4", "nucleotide polymorphism" for studies on the relations between TLR4 SNP polymorphism and the risk of pulmonary tuberculosis that were published before September 1st, 2021. Papers were selected according to the inclusion and exclusion criteria established in advance. The allele and genotype data of the four most widely studied SNP loci (rs4986791, rs4986790, rs11536889, rs10759932) in TLR4 gene were extracted and analyzed by Review Manager 5.3 software. RESULTS: 20 studies including a total of 24727 patients were included in the final meta-analysis. Results of the meta-analysis showed that the C allele of rs10759932 increased the risk of pulmonary tuberculosis (odds ratio - OR: 1.144; 95% confidence interval (CI) 1.043-1.254, P = 0.004). Compared with TT genotype, CC+CT genotype of rs10759932 and CT alone genotype significantly increased the risk of pulmonary tuberculosis (OR = 1.218, 95% CI 1.084-1.369, P = 0.001; OR = 1.227, 95% CI 1.085-1.387, P = 0.001). However, rs4986790, rs4986791 and rs11536889 had no significant correlation with the susceptibility of pulmonary tuberculosis (P > 0.05). CONCLUSION: G allele GG+GA genotype, and the GA genotype of rs4986790; C allele, CC+CT genotype, and the CC genotype of rs10759932 increased the risk of pulmonary tuberculosis, and may potentially be used as a marker for pulmonary tuberculosis diagnosis and monitoring.

Prediction of Sacral Screw Loosening after Lumbosacral Surgeries Involving Rigid Fixation of Sacral Bone Using Preoperative Computed Tomography Scans.

Objective: To find a preoperative computed tomography-based method to predict the incidence of sacral screw loosening and assist surgical planning. Methods: Surgically treated patients for degenerative lumbosacral disorders with rigid pedicle screw fixation of patients with L5-S1 vertebra in our center from January 2016 to January 2021 were retrospectively included in the current study. CT scan attenuation of the horizontal plane of the sacrum was measured with Hounsfield units (HU). Postoperative X-ray tests were used to diagnose screw loosening. The data was analyzed by independent sample t-tests, X 2 analysis, Pearson correlation analysis, and ROC curve analysis. Results: A total of 162 (114 male, 48 female, average age 63.7 ± 7.3 years) patients were included in the final analysis. Significant differences were found between the screw loosening group and nonloosening group concerning the HU value of the sacrum at the horizontal plane (P < 0.01). In ROC curve analysis, AUC was 0.674 (95% CI: 0.592-0.756). A cutoff of 200 HU provided 64.8% sensitivity and 62.4% specificity, and a cutoff of 150 HU provided 90.2% sensitivity. Conclusions: Analyzing 162 patients with at least 12 months of follow-up, we propose cutoff CT attenuation values of 200 HU and 150 HU to take moderate and radical measures of screw augmentation to prevent screw loosening in the sacral bone.

Minimally invasive plate osteosynthesis or conventional intramedullary nailing for distal tibial fractures: A cohort study protocol.

BACKGROUND: Currently, both minimally invasive plate osteosynthesis (MIPO) and intramedullary nailing are the two most commonly used methods of treatment in distal tibial fractures, but controversy still exists regarding the clinical effects of 2 techniques. Our purposes were to compare MIPO and intramedullary nailing for distal tibia shaft fractures by assessing functional outcomes and complications. METHODS: Data were collected retrospectively from the charts of patients treated for distal tibial extra-articular fractures between May 2012 and July 2018. All cases were performed by a single surgeon. Institutional review board approval in the Second Affiliated Hospital of Army Medical University was obtained prior to conducting chart review and analysis. The criteria for inclusion in the study were being aged at least 18 years at the time of diagnosis and having a closed or type I open fracture of the distal third of the tibial diaphysis. The primary outcome compared between the 2 groups was the American Orthopedic Foot and Ankle surgery score. The secondary outcome measures in this trial included Olerud and Molander Ankle Score, radiographic outcomes, and complications. Statistical analysis was performed using SPSS version. P values < .05 were considered statistically significant. RESULTS: We hypothesized that MIPO would be associated with better functional outcomes and fewer complications. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5808).

Covalently functionalized poly(etheretherketone) implants with osteogenic growth peptide (OGP) to improve osteogenesis activity.

Polyetheretherketone (PEEK), as the most promising implant material for orthopedics and dental applications, has bone-like stiffness, excellent fatigue resistance, X-ray transparency, and near absence of immune toxicity. However, due to biological inertness, its bone conduction and bone ingrowth performance is limited. The surface modification of PEEK is an option to overcome these shortcomings and retain most of its favorable properties, especially when excellent osseointegration is desired. In this study, a simple reaction procedure was employed to bind the osteogenic growth peptide (OGP) on the surface of PEEK materials by covalent chemical grafting to construct a bioactive interface. The PEEK surface was activated by N,N'-disuccinimidyl carbonate (DSC) after hydroxylation, and then OGP was covalently grafted with amino groups. The functionalized surface of PEEK samples were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), water contact angle measurement and biological evaluation in vitro. OGP-functionalized PEEK surface significantly promoted the attachment, proliferation, alkaline phosphatase (ALP) activity and mineralization of pre-osteoblast cells (MC3T3-E1). The in vivo rat tibia implantation model is adopted and micro-CT analyses demonstrated that the OGP coating significantly promoted new bone formation around the samples. The in vitro and in vivo results reveal that the modification by covalent chemical functionalization with OGP on PEEK surface can augment new bone formation surrounding implants compared to bare PEEK and PEEK implant modified by covalently attached OGP is promising in orthopedic and dental applications.

Highly Permeable Gelatin/Poly(lactic acid) Fibrous Scaffolds with a Three-Dimensional Spatial Structure for Efficient Cell Infiltration, Mineralization and Bone Regeneration.

Three-dimensional (3D) fibrous scaffolds allowing sufficient cell infiltration are urgently needed for bone tissue engineering. In this study, a highly permeable 3D interconnected scaffold was fabricated by surface bonding of cotton-like nonwoven fibers with micro- and nanoscale architecture using gaseous chloroform. The results of physiochemical characterization indicated that bonding for 90 min with a fiber density of 0.15 g/cm3 could facilitate satisfactory porosity, supportive mechanical properties, and a 3D spatial microstructure for cell ingrowth. Coating with gelatin on the fibers induced highly efficient in vitro mineralization and in vivo bone formation as indicated by mineral deposition and repair of rabbit radius bone defect. The findings from this work demonstrated that these biofunctionalized fibrous scaffolds could bionically represent topographic nanofeatures and biological composition for cell binding affinities similar to those of the natural extracellular matrix (ECM). It can be concluded that the facile fabrication and modification strategy of 3D fibrous scaffolds exhibit promising prospect to fulfill the progressive needs in bone tissue engineering.

Inflammatory transmitter changes during tourniquet-induced limb ischemia-reperfusion injury and the role of ischemic preconditioning / 中国组织工程研究

BACKGROUND:Over-expression of serum interleukin-6 and interleukin-8 may be involved in tourniquet-induced limb ischemia-reperfusion injury to the lung ventilation function. OBJECTIVE:To evaluate the tourniquet effect on serum interleukin-6 and interleukin-8 levels of the rat limb within the safety time limit. METHODS: Sixty rats were randomly divided into control and experimental groups, 30 rats in each group. Rats in the control group had no ischemic preconditioning and were directly subjected to stop bleeding for 2, 3, 4 hours; rats in the experimental group were subjected to ischemic preconditioning (short-time hemostasis for several times within 1 day before ischemia-reperfusion injury), and then underwent 2-, 3-, 4-hour hemostasis at the 2nd day. At 1, 3, 7, 14 days after the recovery of limb blood flow, blood samples were extracted to detect serum interleukin-6 and interleukin-8 levels using ELISA method. RESULTS AND CONCLUSION:The levels of interleukin-6 interleukin-8 showed an increasing and decreasing trend in the two groups, which both reached the peak at the 3rd day (P 0.05), and at 3, 7, 14 days, the level of interleukin-8 in the rats undergoing 4-hour hemostasis was significantly higher than that in the control group (P< 0.05). At 1 and 3 days, the levels of interleukin-6 and interleukin-8 in the experimental group had an increasing trend with the bleeding time and ranked as folows: 2-hour hemostasis < 3-hour hemostasis < 4-hour hemostasis, and there was a significant difference; while in the control group, there was also an increasing trend in the levels of interleukin-6 and interleukin-8, but there was no statistical difference. These findings indicate that the tourniquet preconditioning treatment is preferred at 3 days after limb ischemia-reperfusion injury, when the inflammatory response was the most obvious in rats, and this treatment can dramaticaly reduce inflammatory response. Additionaly, the inflammatory become more obvious with the bleeding time.