DLP printed hDPSC-loaded GelMA microsphere regenerates dental pulp and repairs spinal cord.

Dental pulp regeneration is ideal for irreversible pulp or periapical lesions, and in situ stem cell therapy is one of the most effective therapies for pulp regeneration. In this study, we provided an atlas of the non-cultured and monolayer cultured dental pulp cells with single-cell RNA sequencing and analysis. Monolayer cultured dental pulp cells cluster more closely together than non-cultured dental pulp cells, suggesting a lower heterogeneous population with relatively consistent clusters and similar cellular composition. We successfully fabricated hDPSC-loaded microspheres by layer-by-layer photocuring with a digital light processing (DLP) printer. These hDPSC-loaded microspheres have improved stemness and higher multi-directional differentiation potential, including angiogenic, neurogenic, and odontogenic differentiation. The hDPSC-loaded microspheres could promote spinal cord regeneration in rat spinal cord injury models. Moreover, in heterotopic implantation tests on nude mice, CD31, MAP2, and DSPP immunofluorescence signals were observed, implying the formation of vascular, neural, and odontogenetic tissues. In situ experiments in minipigs demonstrated highly vascularized dental pulp and uniformly arranged odontoblast-like cells in root canals of incisors. In short, hDPSC-loaded microspheres can promote full-length dental pulp regeneration at the root canals' coronal, middle, and apical sections, particularly for blood vessels and nerve formation, which is a promising therapeutic strategy for necrotic pulp.

Evaluation and Comparation of a Novel Surgical Technique and Hemivertebra Resection to the Correction of Congenital Cervical Scoliosis in Lower Cervical and Cervicothoracic Spine.

OBJECTIVE: To report concave-side distraction technique to treat congenital cervical scoliosis in lower cervical and cervicothoracic spine. To evaluate and compare clinical and radiographic results of this procedure with classic hemivertebra resection procedure. METHODS: This study reviewed 29 patients in last 13 years. These patients were divided into convex-side resection group (group R) and concave-side distraction group (group D). Radiographic assessment was based on parameter changes preoperatively, postoperatively and at last follow-up. Demographic data, surgical data and complications were also evaluated and compared between the 2 groups. RESULTS: In group R, mean age was 8.9 ± 3.3 years and follow-up was 46 ± 18 months. Operation time and blood loss averaged 500 ± 100 minutes, 703 ± 367 mL. In group D, mean age was 9.9 ± 2.8 years and follow-up was 34 ± 14 months. Operation time and blood loss averaged 501 ± 112 minutes, 374 ± 181 mL. Structural Cobb angle was corrected from 29.4° ± 12.5° to 5.3° (2.1°-18.1°) (p = 0.001) and 33.7° ± 14.1° to 12.8° ± 11.4° (p < 0.001) in groups R and D. Compensatory Cobb angle had a spontaneous correction rate of 59.6% (40.0%-80.8%) and 59.7% ± 23.0% in groups R and D. Mandibular incline, clavicle angle and spine coronal balance were significantly improved at last follow-up in both groups. All correction rates were not statistically different between groups. However, group D had significant less blood loss (p < 0.001) and operation time (p = 0.004) per vertebra than group R. Seven patients developed C5 nerve root palsy and recovered by 6 months of follow-up. CONCLUSION: Both surgical procedures are safe and effective in correcting congenital cervical scoliosis. But concave-side distraction technique has less blood loss and time-consuming during surgery, which provides a better option for the treatment of congenital cervical scoliosis.

Tissue-Adhesive Paint of Silk Microparticles for Articular Surface Cartilage Regeneration.

Current biomaterials and tissue engineering techniques have shown a promising efficacy on full-thickness articular cartilage defect repair in clinical practice. However, due to the difficulty of implanting biomaterials or tissue engineering constructs into a partial-thickness cartilage defect, it remains a challenge to provide a satisfactory cure in joint surface regeneration in the early and middle stages of osteoarthritis. In this study, we focused on a ready-to-use tissue-adhesive joint surface paint (JS-Paint) capable of promoting and enhancing articular surface cartilage regeneration. The JS-Paint is mainly composed of N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrosophenoxy) butanamide (NB)-coated silk fibroin microparticles and possess optimal cell adhesion, migration, and proliferation properties. NB-modified silk fibroin microparticles can directly adhere to the cartilage and form a smooth layer on the surface via the photogenerated aldehyde group of NB reacting with the -NH2 groups of the cartilage tissue. JS-Paint treatment showed a significant promotion of cartilage regeneration and restored the smooth joint surface at 6 weeks postsurgery in a rabbit model of a partial-thickness cartilage defect. These findings revealed that silk fibroin can be utilized to bring about a tissue-adhesive paint. Thus, the JS-Paint strategy has some great potential to enhance joint surface regeneration and revolutionize future therapeutics of early and middle stages of osteoarthritis joint ailments.

Evaluation of a combined approach to the correction of congenital cervical or cervicothoracic scoliosis.

BACKGROUND CONTEXT: An anteroposterior combined approach has been used for the treatment of congenital cervical or cervicothoracic scoliosis. However, its outcomes and surgical risks have not been clarified. PURPOSE: We analyzed the characteristics of congenital cervical and cervicothoracic scoliosis and evaluated the outcomes of an anteroposterior combined approach for its treatment. STUDY DESIGN: We carried out a retrospective clinical study of prospectively collected data. PATIENT SAMPLE: Sixteen patients were treated between 2009 and 2013. Their average age was 9.2years. OUTCOME MEASURES: Radiographic and surgical outcomes were measured and recorded. We compared morphological parameters and preoperative and postoperative results. METHODS: All patients underwent surgery with a combined approach. The following radiographic parameters were measured: head tilt (HT), mandible incline (MI), shoulder balance (SB), structural and compensatory curves, cervical lordosis, C7 central sacral vertical line (C7-CSVL) ratio, C7 sagittal vertical axis (C7-SVA) ratio, C2-C7 SVA ratio, the angle between the upper endplate of the T2 vertebra and a horizontal line (T2 tilt), gravity line ratio. Demographic and surgical data were also collected. RESULTS: On average, the duration of follow-up was 68.0 months, surgical blood loss was 675mL, and the duration of surgery was 400.5 minutes. The average correction rate was 64.9% in the structural curve and 29.5% in the compensatory curve. Statistical analysis showed that MI significantly correlated with HT and SB (p<.05). The C7-CSVL ratio correlated with the HT, MI, and SB (p<.05). The C7-SVA ratio correlated with the structural curve and cervical lordosis (p<.05), and the gravity line ratio correlated with the structural and compensatory curve, cervical lordosis, and C7-SVA ratio (p<.05). Moreover, there were correlations between the structural and compensatory curves as well as between the structural curve and cervical lordosis (p<.05). There were significant differences before and after surgery in HT, MI, and structural and compensatory curves. Four patients developed nerve root palsy after surgical correction and totally recovered by 6 months of follow-up. CONCLUSION: The combined approach is an effective surgical option for congenital cervical or cervicothoracic scoliosis. The resection of the hemivertebra cannot only improve head-neck aesthetic appearance but can also maintain the growth potential of the neck.

A strongly adhesive hemostatic hydrogel for the repair of arterial and heart bleeds.

Uncontrollable bleeding is a major problem in surgical procedures and after major trauma. Existing hemostatic agents poorly control hemorrhaging from traumatic arterial and cardiac wounds because of their weak adhesion to wet and mobile tissues. Here we design a photo-reactive adhesive that mimics the extracellular matrix (ECM) composition. This biomacromolecule-based matrix hydrogel can undergo rapid gelling and fixation to adhere and seal bleeding arteries and cardiac walls after UV light irradiation. These repairs can withstand up to 290 mm Hg blood pressure, significantly higher than blood pressures in most clinical settings (systolic BP 60-160 mm Hg). Most importantly, the hydrogel can stop high-pressure bleeding from pig carotid arteries with 4~ 5 mm-long incision wounds and from pig hearts with 6 mm diameter cardiac penetration holes. Treated pigs survived after hemostatic treatments with this hydrogel, which is well-tolerated and appears to offer significant clinical advantage as a traumatic wound sealant.

A Novel Method of Automatic Plant Species Identification Using Sparse Representation of Leaf Tooth Features.

Automatic species identification has many advantages over traditional species identification. Currently, most plant automatic identification methods focus on the features of leaf shape, venation and texture, which are promising for the identification of some plant species. However, leaf tooth, a feature commonly used in traditional species identification, is ignored. In this paper, a novel automatic species identification method using sparse representation of leaf tooth features is proposed. In this method, image corners are detected first, and the abnormal image corner is removed by the PauTa criteria. Next, the top and bottom leaf tooth edges are discriminated to effectively correspond to the extracted image corners; then, four leaf tooth features (Leaf-num, Leaf-rate, Leaf-sharpness and Leaf-obliqueness) are extracted and concatenated into a feature vector. Finally, a sparse representation-based classifier is used to identify a plant species sample. Tests on a real-world leaf image dataset show that our proposed method is feasible for species identification.

Control of COD/N ratio for nutrient removal in a modified membrane bioreactor (MBR) treating high strength wastewater.

A modified membrane bioreactor (MBR) system has been developed to evaluate the efficiency of nutrient removal in treating synthetic high strength water. This study examined the effect of influent COD/N ratio on this system. Results showed that above 95.0% removal efficiencies of organic matter were achieved; indicating COD removal was irrespective of COD/N ratio. The average removal efficiencies of total nitrogen (TN) and phosphate (PO(4)(3-)-P) with a COD/N ratio of 9.3 were the highest at 90.6% and 90.5%, respectively. Furthermore, TN removal was primarily based on simultaneous nitrification and denitrification (SND) process occurred in the aerobic zone. Decreased COD/N ratios to 7.0 and 5.3, TN removal efficiencies in steady-states were 69.3% and 71.2%, respectively. Both aerobic SND and conventional biological nitrification/denitrification contributed to nitrogen removal and the latter played dominant effect. PO(4)(3-)-P-release and uptake process ceased in steady-states of COD/N 7.0 and 5.3, which decreased its removal efficiency significantly.

[Combined MBR-RO process treating high strength wastewater].

The performances of A/O-MBR/RO system for the removal of nitrogen and COD were investigated. Result indicated that most organic was removed in the A/O-MBR and the average removal efficiency was 95.6%. The water quality of RO effluent which in terms of TOC < 0.9 mg x L(-1), TN < 12.65 mg x L(-1), total rigidity < 0.038 mol x L(-1), total alkalinity < 14.6 mg x L(-1) could meet the water quality requirements for the town wastewater reuse. The average removal efficiency of organic was almost unaffected by COD/N, but the process of TN removal was affected by COD/N. TN removal was primarily based on simultaneous nitrification and denitrification (SND) process occurred in the aerobic zone and the average removal efficiency of TN was 89.4% with average COD/N of 10.2. Both aerobic SND and conventional biological nitrification/denitrification contributed to nitrogen removal, the average removal efficiency of TN was 72%, 74% with average COD/N of 7.1 and 5.6. The fouling cake layer formed on the RO membrane surface was observed by scanning electric microscopy. The membrane fouling was characterized by Fourier transform infrared spectroscopy technique which showed that the major components of the foulants were soluble microbe products.