Biomimetic crystallization for long-pursued -COOH-functionalized gold nanocluster with near-infrared phosphorescence.

As an interdisciplinary product, water-soluble gold nanoclusters (AuNCs) stabilized by ligands containing carboxyl (-COOH) group have garnered significant attention from synthetic chemists and biologists due to their immense potential for biomedical applications. However, revealing the crystallographic structures of -COOH-functionalized AuNCs remains a bottleneck. Herein, we successfully applied the salting-out method to obtain a series of high-quality single crystals of -COOH-functionalized Au25 nanoclusters and revealed their crystallographic structures. Particularly, K3Au25(2-Hmna)9(mna)6]- (Au25a) protected by 2-mercaptonicotinic acid features an unprecedented tetrameric Au4(SRS)3(SRS,N)2 staple motifs surrounding the icosahedral Au13 kernel, breaking the traditional perception on the structure of Au25(SR)18. Au25a exhibits a distinct near-infrared emission at 970 nm with long lifetime of 8690 ns, which have been studied by transient absorption spectroscopy and time-dependent density functional theory. This work compensates for the research gap in the experimental structure of -COOH-functionalized AuNCs and opens up a new avenue to explore their structure-property correlations.

Two triplet emitting states in one emitter: Near-infrared dual-phosphorescent Au20 nanocluster.

Intrinsic dual-emission (DE) of gold nanoclusters in the near-infrared (NIR) are fascinating for fundamental importance and practical applications, but their synthesis remains a formidable challenge and sophisticated excited-state processes make elucidating DE mechanisms much more arduous. Here, we report an all-alkynyl-protected gold nanocluster, Au20, showing a prolate Au12 tri-octahedral kernel surrounded by two Au2(CZ-PrA)3 dimers, four Au(CZ-PrA)2 monomers, and two CZ-PrA- bridges. Au20 exhibits distinguished photophysical properties including NIR DE at 820 and 940 nm, microsecond radiative relaxation, and 6.26% photoluminescent quantum yield at ambient environment in nondegassed solution. Combining systematic studies on steady/transient spectroscopy and theoretical calculation, we identified two triplet charge transfer (CT) states, ligand-to-kernel and kernel-based CT states as DE origins. Furthermore, this NIR DE exhibits highly independent and sensitive response to surrounding environments, which well coincide with its mechanism. This work not only provides a substantial structure model to understand a distinctive DE mechanism but also motivates the further development of NIR DE materials.

Therapeutic potential of dental pulp stem cells and their derivatives: Insights from basic research toward clinical applications.

For more than 20 years, researchers have isolated and identified postnatal dental pulp stem cells (DPSCs) from different teeth, including natal teeth, exfoliated deciduous teeth, healthy teeth, and diseased teeth. Their mesenchymal stem cell (MSC)-like immunophenotypic characteristics, high proliferation rate, potential for multidirectional differentiation and biological features were demonstrated to be superior to those of bone marrow MSCs. In addition, several main application forms of DPSCs and their derivatives have been investigated, including stem cell injections, modified stem cells, stem cell sheets and stem cell spheroids. In vitro and in vivo administration of DPSCs and their derivatives exhibited beneficial effects in various disease models of different tissues and organs. Therefore, DPSCs and their derivatives are regarded as excellent candidates for stem cell-based tissue regeneration. In this review, we aim to provide an overview of the potential application of DPSCs and their derivatives in the field of regenerative medicine. We describe the similarities and differences of DPSCs isolated from donors of different ages and health conditions. The methodologies for therapeutic administration of DPSCs and their derivatives are introduced, including single injections and the transplantation of the cells with a support, as cell sheets, or as cell spheroids. We also summarize the underlying mechanisms of the regenerative potential of DPSCs.

[Application of Extracellular Vesicles Derived from Vascular Endothelial/Endothelial Progenitor Cells in Tissue Regeneration and Repair].

Extracellular vesicles can be released by almost all types of cells and are important mediators of intercellular signal transmssion. Extracellular vesicles regulate the function and activity of recipient cells by delivering biologically active molecules such as proteins and nucleic acids, which is of great significance in tissue repair and regeneration. According to numerous studies, extracellular vesicles derived from endothelial/endothelial progenitor cells can induce cell proliferation and differentiation, inhibit cell apoptosis, and promote angiogenesis, playing an increasingly important role in regenerative medicine. We reported in this review the latest findings on applying extracellular vesicles derived from endothelial/endothelial progenitor cells in tissue regeneration and repair, and discussed the challenges and future development directions of their application in the field of regenerative medicine.

Microspheres and their Potential in Endodontic Regeneration Application.

Microspheres have been widely utilised as versatile carriers in biomedical applications. In recent years, as a new type of injectable scaffold, microspheres have attracted increasing attention in the field of regenerative medicine owing to their various advantages including their small size, large specific surface area and mimicry of the 3D native environment. These characteristics enable them to adopt the narrow and irregular anatomy of the tooth and become an ideal scaffold for endodontic regeneration. Microspheres play an important role in carrying biologics (cells, biomolecules and drugs), which effectively regulate the fate of stem cells and control the release of growth factors and drugs. Cell-laden microspheres, which can be divided into microcarriers and microcapsules, have great application prospects in dental pulp regeneration. This paper summarises the properties and characteristics of microsphere scaffolds used in tissue engineering, placing emphasis on their advantages and applications in endodontic regeneration.

Advances in Research on Stem Cell-Based Pulp Regeneration.

Although root canal therapy is the most common and widely used treatment at clinical presentation, there are still some postoperative complications. As cell biology and tissue engineering techniques advance rapidly, the use of biological therapy to regenerate dental pulp has become a new trend; Relevant literatures in recent five years were searched using key words such as "root canal therapy", "Dental pulp stem cells", "Dental pulp regeneration", and "Cell homing" in PubMed, Web of Science, etc; Dental pulp stem cells (DPSCs) have multi-differentiation potential, self-renewal capability, and high proliferative ability. Stem cell-based dental pulp regeneration has emerged as a new research hot spot in clinical therapy. Recently, dental pulp-like structures have been generated by the transplantation of exogenous DPSCs or the induction of homing of endogenous DPSCs. Studies on DPSCs are important and significant for dental pulp regeneration and dental restoration; In this review, the existing clinical treatment methods, dental pulp regeneration, and DPSC research status are revealed, and their application prospects are discussed. The stem cell-based pulp regeneration exerts promising potential in clinical therapy for pulp regeneration.

Neurotrophic effects of dental pulp stem cells in repair of peripheral nerve after crush injury.

BACKGROUND: Nerve diseases and injuries, which are usually accompanied by motor or sensory dysfunction and disorder, impose a heavy burden upon patients and greatly reduce their quality of life. Dental pulp stem cells (DPSCs), derived from the neural crest, have many characteristics that are similar to those of neural cells, indicating that they can be an ideal source for neural repair. AIM: To explore the potential roles and molecular mechanisms of DPSCs in crushed nerve recovery. METHODS: DPSCs were isolated, cultured, and identified by multilineage differentiation and flow cytometry. Western blot and immunofluorescent staining were applied to analyze the expression levels of neurotrophic proteins in DPSCs after neural induction. Then, we collected the secretions of DPSCs. We analyzed their effects on RSC96 cell proliferation and migration by CCK8 and transwell assays. Finally, we generated a sciatic nerve crush injury model in vivo and used the sciatic function index, walking track analysis, muscle weight, and hematoxylin & eosin (H&E) staining to further evaluate the nerve repair ability of DPSCs. RESULTS: DPSCs highly expressed several specific neural markers, including GFAP, S100, Nestin, P75, and NF200, and were inclined toward neural differentiation. Furthermore, neural-induced DPSCs (N-DPSCs) could express neurotrophic factors, including NGF, BDNF, and GDNF. The secretions of N-DPSCs could enhance the proliferation and migration of Schwann cells. In vivo, both DPSC and N-DPSC implants alleviated gastrocnemius muscle atrophy. However, in terms of anatomy and motor function, as shown by H&E staining, immunofluorescent staining, and walking track analyses, the repair effects of N-DPSCs were more sustained, potent, and effective than those of DPSCs and the controls. CONCLUSION: In summary, this study demonstrated that DPSCs are inclined to differentiate into neural cells. N-DPSCs express neurotrophic proteins that could enhance the proliferation and migration of SCs. Furthermore, our results suggested that N-DPSCs could help crushed nerves with functional recovery and anatomical repair in vivo. Thus, DPSCs or N-DPSCs could be a promising therapeutic cell source for peripheral nerve repair and regeneration.

[A Novel Chemically Defined Medium Enhanced the Osteogenic Potential and Periodontal Bone Regeneration of Dental Papilla Cells].

OBEJECTIVE: To investigate the role of a novel chemically defined medium (CDM) in the regulation of dental papilla cells (DPCs) functional phenotype in vitro and periodontal bone regeneration in vivo. METHODS: DPCs were isolated and cultured in conventional medium (CM) or CDM. The surface makers, and the proliferation, migration and osteogenic differentiation abilities of DPCs were evaluated. In vivo, the DPCs that mixed with collagen gel were implanted into the model rats in the defect of periodontal to repair the periodontal tissue. Regeneration of the tissues was examined by microcomputed tomography and histological observation. RESULTS: DPCs in the CM group and CDM group showed similar surface markers. Compared to the CM group, the CDM significantly enhanced the proliferation, colony-forming efficiency and migration of DPCs in vitro. In addition, real time PCR showed that the expression levels of osteogenesis-related genes, Runx2, Alp and Opn. were significantly enhanced in DPCs in the CDM group. DPCs cells treated with CDM also exhibited higher alkaline phosphatase activity and stronger ability of formation of mineralized nodules in vitro. In vivo, DPCs from CDM group significantly enhanced the periodontal bone regeneration and the reconstruction of periodontal bone tissues in rat periodontal defect model. CONCLUSION: CDM is a suitable medium to culture DPCs for periodontal bone regeneration. This research provided a substitute for basic research and set the stage for future clinical application of stem cell transplantation.

Global synthesis of effects of plant species diversity on trophic groups and interactions.

Numerous studies have demonstrated that plant species diversity enhances ecosystem functioning in terrestrial ecosystems, including diversity effects on insects (herbivores, predators and parasitoids) and plants. However, the effects of increased plant diversity across trophic levels in different ecosystems and biomes have not yet been explored on a global scale. Through a global meta-analysis of 2,914 observations from 351 studies, we found that increased plant species richness reduced herbivore abundance and damage but increased predator and parasitoid abundance, predation, parasitism and overall plant performance. Moreover, increased predator/parasitoid performance was correlated with reduced herbivore abundance and enhanced plant performance. We conclude that increasing plant species diversity promotes beneficial trophic interactions between insects and plants, ultimately contributing to increased ecosystem services.

Expert Consensus on Procedures and Operations of Navigation-guided Needle Biopsy Techniques for Skull Base Tumours.

Skull base surgery is an interdisciplinary subject. The anatomical structures in the skull base related to oral and maxillofacial surgery include the parapharyngeal space, the pterygopalatine fossa and the infratemporal space. This operative area is one of the most challenging surgical areas in oral and maxillofacial surgery due to its deep site, complex anatomy and high risk. Obtaining pathological information of the tumour preoperatively may help surgeons optimise their treatment plan. Needle biopsy is one of the major minimally invasive techniques that allows preoperative pathological results to be obtained. The navigation technology, which is developing rapidly nowadays, provides a reliable assistance for deep tissue biopsy surgery. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association formulated an expert consensus on the procedures and operations of navigation-guided needle biopsy techniques for skull base tumours, so as to standardise and promote the application and operation of navigation-guided needle biopsy for skull base tumours.

Expert Consensus for the Treatment Algorithm for Navigationassisted Reconstruction of Maxillofacial Deformities.

Deformities of the maxillofacial region following trauma and ablative surgery are devastating and not uncommon. Reconstruction of such defects is a surgically challenging procedure. Conventionally, reconstruction of dental arch defects lacks preoperative customised planning and relies heavily on the surgeon experience to ensure optimum surgical outcomes. The restoration of the dental arch shape and function has taken precedence after an extensive tumour resection surgery, especially in the current age of technological advancement. Thus, personalised and accurate reconstruction of dental arch defects has become a new goal. Computer-assisted surgery, especially navigation-assisted surgery, has gained popularity of late, in reconstructing deformities and restoring facial symmetry, appearance and function in the maxillofacial region. This technology provides a clearer three-dimensional visualisation of the area of interest and its relationship with the adjacent vital structures. Together with preoperative virtual surgical planning, it allows more specific and accurate osteotomies, thus reducing the ischemia and total operating times substantially. The risk of complications is also minimised whilst improving the final surgical outcomes. The use of the intraoperative navigation system and other computer-assisted surgical techniques during surgery can significantly improve the precision of the reconstruction of dental arch deformities, and achieve personalised and functional reconstructive goals while enhancing the quality of life of patients postoperatively. The Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association provides the present professional perspective and treatment protocol for navigation-guided reconstruction of dental arch defects, to allow standardisation of the technique while promoting its application among oral and maxillofacial surgeons.

Expert Consensus on Navigation-guided Unilateral Delayed Zygomatic Fracture Reconstruction Techniques.

The zygoma is located in the medial and lateral parts of the face, supporting the midfacial contour. The forward projection of the zygoma and the zygomatic arch often expose them to injury. Fractures of the zygoma can lead to the displacement of the zygoma and the zygomatic arch, causing facial collapse deformity. For delayed zygomatic fractures, the loss of normal anatomical landmarks caused by the malunion of the fracture lines and remodelling of the bony contour makes it difficult to determine the correct positions of the zygomatic bones. In such cases, ideal and steady outcomes with satisfactory midface symmetry have been difficult to obtain using traditional surgical methods. Nowadays, the application of digital surgical software and surgical navigation helps surgeons to perform accurate preoperative simulations to obtain ideal three-dimensional virtual surgical plans and achieve accurate reduction by intraoperative navigation systems, which increase the accuracy and predictability of fracture reduction outcomes. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association have fully discussed and formulated an expert consensus on navigation-guided unilateral delayed zygomatic fracture reconstruction techniques to standardise the clinical operation procedures and promote the application.

Expert Consensus on Navigation-guided Unilateral Orbital Fracture and Orbital Floor Reconstruction Techniques.

Orbital fracture and orbital floor reconstruction surgery is characterised by limited surgical exposure and high risks. Before the advent of digital technology, the design and implementation of the surgical scheme for orbital floor reconstruction surgery mainly depended on the intuitive understanding of imaging and the clinical experience of surgeons, with strong unpredictability and experience dependence. Surgical navigation systems with real-time positioning and imaging functions, when used in orbital reconstruction surgery, can detect the real-time intraoperative position, avoid risks, and assist in locating the reconstruction position to ensure the accuracy of orbital reconstruction, with the help of a preoperative surgical plan. Many studies have confirmed its effect. Unilateral orbital fracture and orbital floor reconstruction surgery is one of the earliest and most widely used surgical techniques in maxillofacial surgery. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association have fully discussed and formulated this expert consensus on navigation-guided unilateral orbital fracture and orbital floor reconstruction techniques to standardise the clinical surgical procedures and promote its application.

[Clinical and genetic features of Chinese kindreds with Van der Woude syndrome caused by interferon regulatory factor 6 mutation].

OBJECTIVE: This study aimed to investigate the clinical phenotype and genetic characteristics of Chinese families with Van der Woude syndrome (VWS). METHODS: Clinical manifestations between 14 families and within each family were recorded. Possible inheritance modes and pathogenic genes were analyzed. Phenotypic distribution and gene frequencies were calculated. RESULTS: Of the pedigrees investigated, an autosomal dominant inheritance pattern was suggested. All patients had typical symptoms. The pathogenic gene was interferon regulatory factor 6 (IRF6). Phenotypic distribution frequencies were as follows: lip pits (91.9%), cleft lip and/or palate (73.0%), and hyperdontia (8.1%). There were significant differences in clinical phenotypes among individuals of different families and individuals of the same family. CONCLUSIONS: VWS in a Chinese population was dominantly inherited with high penetrance and variable expressivity. The pathogenic gene was IRF6. VWS in a Chinese population was genotyped as VWS1.

Application of computer-assisted surgery techniques in the management of zygomatic complex fractures.

Patients suffering from zygomatic complex fractures always present facial deformity and dysfunctions, and thereafter develop psychological and physiological problems. It is really hard to get an ideal prognosis for the zygomatic complex fractures because of the complicated anatomical structures. Computer-assisted surgery techniques, as the new emerging auxiliary methods, can optimize the surgical protocol, predict operation outcomes, and improve the accuracy and quality of the operation. Meanwhile the postoperative complications can be reduced effectively. This review aims to provide a comprehensive overview of the application of computer-assisted surgery techniques in the management of zygomatic complex fractures.

Increasing plant diversity with border crops reduces insecticide use and increases crop yield in urban agriculture.

Urban agriculture is making an increasing contribution to food security in large cities around the world. The potential contribution of biodiversity to ecological intensification in urban agricultural systems has not been investigated. We present monitoring data collected from rice fields in 34 community farms in mega-urban Shanghai, China, from 2001 to 2015, and show that the presence of a border crop of soybeans and neighboring crops (maize, eggplant and Chinese cabbage), both without weed control, increased invertebrate predator abundance, decreased the abundance of pests and dependence on insecticides, and increased grain yield and economic profits. Two 2 year randomized experiments with the low and high diversity practices in the same locations confirmed these results. Our study shows that diversifying farming practices can make an important contribution to ecological intensification and the sustainable use of associated ecosystem services in an urban ecosystem.

Correlation between Condylar Fracture Pattern after Parasymphyseal Impact and Condyle Morphological Features: A Retrospective Analysis of 107 Chinese Patients.

BACKGROUND: The treatment of the condylar fractures is difficult. Factors that result in the fractures are complex. The objective of this morphometric study was to investigate the relationship between condylar fracture patterns and condylar morphological characteristics. METHODS: We conducted a retrospective analysis of 107 patients admitted to the West China Hospital of Stomatology for bilateral condylar fractures caused by parasymphyseal impact. The patients were divided into five groups according to the type of condylar fracture. Ten parameters were evaluated on three-dimensional (3D) reconstruction mandible models through the Mimics 16.0 (Materialize Leuven, Belgium) anthropometry toolkit. Each parameter of the 3D models was analyzed using multivariate analysis. Multinomial logistic regression analyses were used to examine the relationships between the five groups. RESULTS: The results showed that the differences of condylar head width (M1), condylar neck width (M3), the ratio of condylar head width to condylar anteroposterior diameter (M1/M2), the ratio of condylar head width to condylar neck width (M1/M3), the ratio of condylar height to ramus height (M8/M7), and mandibular angle (M10) were statistically significant (p < 0.05). Type A condylar head fractures were positively associated with M1 (compared to Type B: OR =1.627, 95% CI: 1.123, 2.359; compared to Type C: OR = 1.705, 95% CI: 1.170, 2.484) and M1/M2 (compared to Type B: OR =1.034, 95% CI: 0.879, 2.484). Type B condylar head fractures were negatively associated with M10 (compared to Type C: OR = 0.909, 95% CI: 0.821, 1.007). Condylar neck fractures were negatively associated with M3 (compared to condylar head: OR = 0.382, CI: 0.203, 0.720 ; compared to condylar base: OR = 0.436, 95% CI: 0.218, 0.874), and positively associated with M1/M3 (compared to condylar head: OR = 1.229, 95% CI: 1.063, 1.420 compared to condylar base: OR = 1.223, 95% CI: 1.034, 1.447). Condylar base fractures were positively associated with M10 (OR = 1.095, 95% CI: 1.008, 1.189) and negatively associated with M8/M7 (OR = 0.855, 95% CI: 0.763, 0.959) as compared with condylar head fractures. CONCLUSIONS: Condylar fracture pattern is associated with the anatomical features of the condyles when a fracture occurs from parasymphyseal impact.

Electromagnetic pulse activated brain microglia via the p38 MAPK pathway.

Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1ß, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (p<0.05) and recovered to the sham group level at 24h after EMP exposure. Levels of NO, TNF-α and IL-10 also changed significantly in vivo and in vitro after EMP exposure. The protein level of p38 and phosphorylated p38 increased significantly after EMP exposure (p<0.05) and recovered to sham levels at 12 and 24h, respectively. Protein and phosphorylated protein levels of ERK and JNK did not change. SB203580 (p38 inhibitor) partly prevented the change in NO, IL-10, IL-1ß, TNF-α levels induced by EMP exposure. Taken together, these results suggested that EMP exposure (200kV/m, 200 pulses) could activate microglia in rat brain and affect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process.

[Extraction of Adipogenic Secretory Factors: a Comparison Between Adherent Culture and Suspension Culture].

OBJECTIVE: To optimize the extraction method of secretory factors from adipose tissue explant (SFAE) in vitro. METHODS: SFAE were obtained through adherent culture (SFAE-A) and suspension culture (SFAE-S) and concentrated by filtration and centrifugation. The yield of SFAE was compared using BCA protein detection kit. P3 adipose-derived stem cells (ADSCs) were induced with equal amount of SFAE for 7-13 d, before the state of adipogenesis between suspension culture and adherent culture was compared by microscope observation and oil red O staining. RESULTS: The average amount of SFAE yielded from adherent culture and suspension culture did not show significant difference. While the yield of SFAE from suspension culture was consistent at 8. 7 mg per gram of adipose tissue, the adherent culture generated an inconsistent result in the four repeat experiments, ranging from 7. 3 mg to 12. 4 mg per gram of adipose tissue. Moreover, ten more flasks and better distribution were needed for adherent culture to acquire an equal amount of SFAE in comparison with suspension culture. SFAE from both adherent and suspension culture promoted the adipogenesis of P3 adipose-derived stem cells. No differences on the adipogenic effect were found between the two extraction methods. CONCLUSION: Secretory factors from adherent culture and suspension culture have the same adipogenesis effect. Suspension culture can save time and labor. The most important advantage of suspension culture is its stable yield of SFAE.

[Improving Threshold Segmentation in 3D Reconstruction of Mandible CT Image].

OBJECTIVE: To develop a new threshold segmentation method for mandible image segmentation. METHODS: CT data of 12 volunteers were exported into Mimics 10. 01. An improved method usinga narrowed threshold range (the maximum threshold range that can segment mandible without manual efforts) was developed in 3D reconstruction, and compared with the traditional method. We used dilation operations to make up the information loss of image borders, by which we obtained an approxinate segment result. A precise segment resultwas eventually arrived with the help of logical operations and region growing. We compared mean time consumptions of the two methods, as well as their 3D reconstruction results using Geomagic Studio 11. 0. RESULTS: The new method generated a success rate of 91. 67% (11/12), with a mean time consumption of (319. 7±125. 3) s. The traditional method took much longer time [(1,261. 3±427. 3) s, P<0. 05] than the new method. Compared with the reconstruction results of traditional method, the new method had an outward deviation of (0. 066±0. 011) mm and an inward deviation of (0. 070±0. 008) mm. Such deviations were less than the minimum distance that a naked eye can discern. The lower limit of the widest threshold range which mandible could be isolated was (507. 72± 100. 31) HU, while the upper limit was (1,133. 33±47. 57) HU. CONCLUSION: The new method we proposed can improve the efficiency of threshold segmentation of mandible.