Designing nanohesives for rapid, universal, and robust hydrogel adhesion.

Nanoparticles-based glues have recently been shown with substantial potential for hydrogel adhesion. Nevertheless, the transformative advance in hydrogel-based application places great challenges on the rapidity, robustness, and universality of achieving hydrogel adhesion, which are rarely accommodated by existing nanoparticles-based glues. Herein, we design a type of nanohesives based on the modulation of hydrogel mechanics and the surface chemical activation of nanoparticles. The nanohesives can form robust hydrogel adhesion in seconds, to the surface of arbitrary engineering solids and biological tissues without any surface pre-treatments. A representative application of hydrogel machine demonstrates the tough and compliant adhesion between dynamic tissues and sensors via nanohesives, guaranteeing accurate and stable blood flow monitoring in vivo. Combined with their biocompatibility and inherent antimicrobial properties, the nanohesives provide a promising strategy in the field of hydrogel based engineering.

Clinical application of integrated angulated screw channel abutment crown in implant-supported rehabilitation of aesthetic area.

OBJECTIVES: To evaluate the clinical effect of integrated angulated screw channel (ASC) abutment crown in implant-supported rehabilitation of the aesthetic area. METHODS: Sixteen patients who received single implant-supported rehabilitation using integrated ASC abutment crown in the aesthetic area were included in the study. After one-year follow-up, the cumulative survival rate, aesthetic effectiveness, bone resorption around implants, and patient satisfaction were analyzed through periapical film, clinical examination, and the visual analog scale (VAS). RESULTS: The implant cumulative survival rate of the integrated ASC abutment crown in the implant-supported rehabilitation of the aesthetic area was 100%. The average pink esthetic index scores reached 9.5, and the white esthetic index scores reached 9.4. The mean marginal bone loss of implants was (0.439±0.123) mm at the mesial side and (0.341±0.118) mm at the distal side. The average VAS satisfaction score was 8.9, which showed that all patients were satisfied with the final restorative effect. CONCLUSIONS: Using integrated ASC abutment crown for implant restoration is an ideal implant restoration design in the aesthetic zone and can be applied clinically.

Interleukin-17A promotes the differentiation of bone marrow mesenchymal stem cells into neuronal cells.

Ischemia or hemorrhagic stroke is one of the leading causes of death and permanent disability in the worldwide population. As a consequence of the potential increasing in stroke, stem cell therapy is currently an area of intense focus. However, there are less data available regarding the promotion of healing efficacy after stroke. The present study aimed to investigate whether the cytokine interleukin-17A (IL-17A) could have a role in promoting the neuronal differentiation of mesenchymal stem cells (MSCs) and to investigate the associated molecular mechanism. Firstly, different concentration of IL-17A at range from 5-40 ng/mL was applied to stimulate bone marrow MSCs (BMSCs) during the course of neurogenic differentiation. Then reverse transcription-PCR, histological analyses and immunofluorescence assays were used to determine the optimum concentration of IL-17A in promoting the neuronal differentiation of BMSCs, which was 20 ng/mL. Mechanistically, Wnt signaling pathway was activated and Notch signaling pathway was suppressed. In addition, there were antergic effect of these two signaling pathways modulating the neurogenic differentiation of BMSCs induced by IL-17A. The present study demonstrated the potential role of IL-17A-based BMSCs strategy for promoting neuronal differentiation in vitro. However, the treatment efficacy could be considerably confirmed in animals with ischemia stroke. Therefore, a more sophisticated strategy that addresses the complicated treatment associated with stroke is needed.

Iron oxide nanoclusters for T 1 magnetic resonance imaging of non-human primates.

Iron-oxide-based contrast agents for magnetic resonance imaging (MRI) had been clinically approved in the United States and Europe, yet most of these nanoparticle products were discontinued owing to failures to meet rigorous clinical requirements. Significant advances have been made in the synthesis of magnetic nanoparticles and their biomedical applications, but several major challenges remain for their clinical translation, in particular large-scale and reproducible synthesis, systematic toxicity assessment, and their preclinical evaluation in MRI of large animals. Here, we report the results of a toxicity study of iron oxide nanoclusters of uniform size in large animal models, including beagle dogs and the more clinically relevant macaques. We also show that iron oxide nanoclusters can be used as T 1 MRI contrast agents for high-resolution magnetic resonance angiography in beagle dogs and macaques, and that dynamic MRI enables the detection of cerebral ischaemia in these large animals. Iron oxide nanoclusters show clinical potential as next-generation MRI contrast agents.

[Cone-beam CT study of bone septa during maxillary sinus lift among Changzhou population].

PURPOSE: To observe the incidence, location, morphological characteristics of sinus septa among Changzhou population, and to investigate the relationship between maxillary posterior teeth loss and bony septum, and the guiding significance for sinus lift. METHODS: One hundred and twenty-four subjects were selected, the preoperative cone-beam CT (CBCT) data was analyzed by NNT software, which provided a three-dimensional measurement of the maxillary sinus septa. SPSS 13.0 software package was used for statistical analysis. RESULTS: 33.87%（42/124）subjects had sinus septa, 27.42%（68/248）sinus had septa. 66.18% (45/68) of the septa were located in the middle region, 22.06% （15/68）in the posterior region, 11.76%（8/68） in the anterior region. The occurrence of sinus septa had no relation with gender, age and loss of teeth. CONCLUSIONS: The sinus septa can be observed by CBCT for the position, pattern, to predict the difficulty of the surgery, and enhance the success rate.

[Establishment and assessment of tibial osteoradionecrosis in rats].

PURPOSE: To establish a rat tibial osteoradionecrosis model and assess the model by observing clinical manifestation and histopathological examinations. METHODS: The right tibia of 6 Sprague Dawley (SD) rats (weighing 200-250 g) was irradiated by a linear accelerator (single fraction 15 Gy, total dose 60 Gy) every second week for four times. Hair and cutaneous changes of the irradiated region were observed one, two, three and four weeks after irradiation, respectively. Histopathological examination was employed to compare the bone tissue between the irradiated region and irradiation-free region. X-ray film was taken to evaluate the bone destruction. SPSS13.0 software package was used for statistical analysis. RESULTS: One week after irradiation, no significant change was observed in the irradiated region. However, the palm of the irradiated limb turned red remarkably in contrast with the opposite one. Two and three weeks after irradiation, trichomadesis was observed in the irradiated region. Four weeks after irradiation, complete trichomadesis and skin ulceration occurred in the irradiated region. In histopathological examinations, hematoxylin-eosin staining showed that bone mass including bone plate thickness, bone marrow cell, bone trabecula decreased significantly in the irradiated region compared with the control side. Moreover, significant bone destruction was found in irradiated group. CONCLUSIONS: We have successfully established a rat tibial model of osteoradionecrosis with radiation at dosage of 60 Gy divided into 4 times.

Chitosan microspheres with an extracellular matrix-mimicking nanofibrous structure as cell-carrier building blocks for bottom-up cartilage tissue engineering.

Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation. Recently, as a valuable alternative, a bottom-up TE approach utilizing cell-loaded micrometer-scale modular components as building blocks to reconstruct a new tissue in vitro or in vivo has been proved to demonstrate a number of desirable advantages compared with the traditional bulk scaffold based top-down TE approach. Nevertheless, micro-components with an ECM-mimicking nanofibrous structure are still very scarce and highly desirable. Chitosan (CS), an accessible natural polymer, has demonstrated appealing intrinsic properties and promising application potential for TE, especially the cartilage tissue regeneration. According to this background, we report here the fabrication of chitosan microspheres with an ECM-mimicking nanofibrous structure for the first time based on a physical gelation process. By combining this physical fabrication procedure with microfluidic technology, uniform CS microspheres (CMS) with controlled nanofibrous microstructure and tunable sizes can be facilely obtained. Especially, no potentially toxic or denaturizing chemical crosslinking agent was introduced into the products. Notably, in vitro chondrocyte culture tests revealed that enhanced cell attachment and proliferation were realized, and a macroscopic 3D geometrically shaped cartilage-like composite can be easily constructed with the nanofibrous CMS (NCMS) and chondrocytes, which demonstrate significant application potential of NCMS as the bottom-up cell-carrier components for cartilage tissue engineering.

The clinical significance of CDK1 expression in oral squamous cell carcinoma

China OBJECTIVES: To evaluate the clinical significance of cyclin-dependent kinase 1 (CDK1) in 77 oral squamous cell carcinomas (OSCC) using immunohistochemical methods. Study DESIGN: Immunohistochemical expression of CDK1 was compared with various clinic pathological features in 77 OSCC and 60 controlled epithelia adjacent to the tumours. In addition, correlation of CDK1 expression and prognostic and the 5-year accumulative survival rate of OSCC were investigated. RESULTS: The CDK1 protein was expressed in 52 cases of 77 tumor tissues (67.5%), compared with 21 cases of 60controlled (35.0%). The expression of CDK1 was significantly correlated with the histological grade of OSCC(P<0.05). The CDK1 protein was over-expressed in recurrent tumors or in those with lymph node metastasis. Statistical analysis showed a significant reduction in the 5-year accumulative survival rate in CDK1 positive cases compared with CDK1 negative cases (P<0.05). Namely, the CDK1 positive patients had poor prognosis. CONCLUSIONS: The expression of CDK1 might serve as malignant degree and prognostic markers for the survival of OSCC

The clinical significance of CDK1 expression in oral squamous cell carcinoma.

OBJECTIVES: To evaluate the clinical significance of cyclin-dependent kinase 1 (CDK1) in 77 oral squamous cell carcinomas (OSCC) using immunohistochemical methods. STUDY DESIGN: Immunohistochemical expression of CDK1 was compared with various clinicopathological features in 77 OSCC and 60 controlled epithelia adjacent to the tumours. In addition, correlation of CDK1 expression and prognostic and the 5-year accumulative survival rate of OSCC were investigated. RESULTS: The CDK1 protein was expressed in 52 cases of 77 tumor tissues (67.5%), compared with 21 cases of 60 controlled (35.0%). The expression of CDK1 was significantly correlated with the histological grade of OSCC (P<0.05). The CDK1 protein was over-expressed in recurrent tumors or in those with lymph node metastasis. Statistical analysis showed a significant reduction in the 5-year accumulative survival rate in CDK1 positive cases compared with CDK1 negative cases (P<0.05). Namely, the CDK1 positive patients had poor prognosis. CONCLUSIONS: The expression of CDK1 might serve as malignant degree and prognostic markers for the survival of OSCC.

[Experimental study of canine bone marrow mesenchymal stem cells combined with calcium phosphate cement for repair of mandibular bone defects in Beagle dogs].

PURPOSE: To evaluate the effects of bone marrow mesenchymal stem cells (BMSCs) combined with calcium phosphate cement (CPC) scaffold for repair of mandibular defect in Beagle dogs. METHODS: BMSCs were isolated from Beagle dogs and cultured in DMEM plus 10% FBS. The induction effect was determined using alizarin red staining or alkaline phosphate staining at 14-day of culture. BMSCs were added to the CPC scaffold for animal experiments. In vivo, three critical size bone defects were surgically created in each side of the mandible. The bone defects were repaired with BMSCs-CPC (scaffolds with composite seeding cells), CPC (scaffold alone) or no materials (blank group). Two dogs were sacrificed at 4-week and 8-week after operation. Gross observation, X-ray imaging, histologic and histometric analyses were performed to evaluate the level of bone formation. RESULTS: Newly formed bones were detected within all defect sites after operation. The BMSCs-CPC group and CPC group showed increased bone formation compared with the blank group. The BMSCs-CPC group exhibited more bone formation and degradation of the material than the CPC group. The percentage of new bone in the BMSCs-CPC and CPC treated group were significantly higher than that in the control group (P<0.05), while the percentage of new bone in the BMSCs-CPC sites was higher than that in the CPC sites (P<0.01); the percentage of residual material in the BMSCs-CPC sites was lower than that in the CPC sites (P<0.01) 4 weeks and 8 weeks after operation. CONCLUSIONS: Using the theory of tissue engineering, BMSCs composite CPC compound is an effective method in promoting new bone regeneration, which has a positive influence on the bone space preservation.

[A study on the effect of biomineralization and phosphorylation performed on the titanium implant surfaces].

OBJECTIVE: To suggest a chemical surface treatment for titanium and to initiate the formation of hydroxycarbonated apatite (HCA) on titanium surface during in vitro bioactivity tests in simulated body fluid (SBF). METHODS: To improve the bone-bonding ability of Ti implants, commercially pure titanium (cpTi) by a simple chemical pre-treatment in orthophosphoric acid (H(3)PO(4)) with different density was activated, and then the phosphorylation specimens were soaked in SBF to investigate the function of biomineralization. RESULTS: The scanning electron microscope (SEM) photographs showed that the surfaces of the pre-treated samples were characterized by a complex construction, which consisted of a mesh-like morphology matrix (a micro-roughened surface) and an uniform surface with different morphous of titanium dihydrogen orthophosphate [Ti(H(2)PO(4))(3)] crystal. After 14 days in SBF a homogeneous biomimetic apatite layer precipitated. CONCLUSIONS: These data suggest that the treatment of titanium by acid etching in orthophosphoric acid is a suitable method to provide the titanium implant with bone-bonding ability.