Marine collagen peptides: A novel biomaterial for the healing of oral mucosal ulcers.

The purpose of this study was to analyze the therapeutic effects of marine collagen peptides (MCPs) from tilapia skin on oral mucosal ulcers in a rat model. CCK-8 and wound healing assays were performed in vitro to evaluate proliferation and migration of L929 cells after treatment with MCPs. The effects of MCPs on the healing of oral mucosal ulcers in a rat model were macroscopically and microscopically analyzed in vivo. Results showed that MCPs promoted proliferation and migration of L929 cells. Moreover, 75%MCPs enhanced the ulcer healing process, suppressed inflammatory response and up-regulated the expression levels of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). MCPs are potentially used as a new therapeutic strategy for oral mucosal ulceration.

Postsurgical Pain and Implant Osseointegration Failure: A Case Control Study.

Aim: The relationship between postsurgical pain and osseointegration was evaluated and analyzed in this study. Material and method. 27 patients, ranging in age from 35 to 72 years old, 12 males and 15 females, who received dental implants and failed to achieve osseointegration from Tianjin Medical University Second Hospital, were analyzed and studied in the following aspects: bone density, initial torque, one- or two-stage surgery, postsurgical pain, postsurgical swelling, and radiographic evidence of osseointegration failure. Result: 5 patients were assessed to be D4 bone density and 7 cases were assessed to be D3 bone density, 2 patients were assessed to be D2 bone density and 13 patients were assessed to be D1 bone density. All cases were documented with clinically acceptable initial torque. Among the 27 cases, 2 of them were one-stage nonsubmerged surgery and 25 cases were two-stage submerged surgery. 25 out of 27 patients reported moderate to severe pain lasting for more than 72 hours. Radiologic examinations failed to offer any indication of poor osseointegration in the 7-day postsurgical follow-up. Conclusion: Moderate to severe postsurgical pain lasting more than 72 hours displays high odd ratio of poor osseointegrate. The radiological examinations alone failed to offer any valuable evidence for the early detection of osseointegration failure in this study.

A novel natural-derived tilapia skin collagen mineralized with hydroxyapatite as a potential bone-grafting scaffold.

Collagen is widely used in medical field because of its excellent biocompatibility and bioactivity. To date, collagen for biomedical use is always derived from bovine or swine. The purpose of this study was to evaluate collagen-based biomaterials from non-mammalian donors for bone repair. Thus, tilapia skin collagen-hydroxyapatite (T-col/HAp) scaffolds were fabricated in three different proportions and then cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide (EDC-NHS). The scaffolds were evaluated for their microstructure, chemical and physical properties, mechanical strength and degradability. Then the in vitro responses of bone mesenchymal stem cells (BMSCs) to the scaffolds were investigated in terms of cellular proliferation, differentiation, and mineralization. At last, the scaffolds were implanted into rat skull critical defections to investigate the potential of osteogenic activities. As a result, the pore sizes and the porosities of the scaffolds were approximately 106.67-196.67 µm and 81.5%-66.7%. Pure collagen group showed a mechanical strength of 0.065 MPa, and the mechanical strength was significantly enhanced almost 17 times and 32 times in collagen/HAp ratio 1:4 and 1:9 groups. In vitro studies revealed the most prominent and healthy growth of BMSCs in collagen/HAp ratio 1:4 group. All the scaffolds showed certain osteogenic activities and those loaded with small amount of hydroxyapatite showed the strongest bioactivities. The micro-CT showed that the critical bone defect was almost filled with generated bone 6 months after implantation in collagen/HAp ratio 1:4 group. The biomechanics tests further confirmed the highest generated bone strength was in the collagen/HAp ratio 1:4 group. This study indicated aquatic collagen might be a potential alternative for type I collagen from mammals in bone tissue engineering. The combination of collagen and inorganic materials was also important and appropriate inorganic component loading can achieve both osteogenic quality and osteogenic efficiency to a certain extent.

Scientometric Analysis of Dental Implant Research over the Past 10 Years and Future Research Trends.

BACKGROUND: We conducted a bibliometrics analysis to explore the recent trends in dental implant research which could help researchers have a clear grasp of the relevant research hotspots and prospects. Material and Methods. Altogether, 15,770 articles on dental implants, from January 1, 2010, to October 31, 2019, were selected from the Web of Science Core Collection. We used BICOMB software to extract the high-frequency MeSH terms and construct binary and coword matrices. gCLUTO software was used for biclustering and visual analysis, Ucinet 6 software for social network analysis, SCIMAT software for strategic diagram building, Citespace 5.5 software to form timeline visualization, and VOSviewer software, eventually, for bibliometrics cocitation network. RESULTS: Altogether, 72 high-frequency keywords were extracted from the selected articles and 4 clusters and 7 subcategories were identified through biclustering analysis in the dental implant research field. The use of the strategic diagram also enabled us to find the research hotspot and development trends. CONCLUSIONS: The survival rate of dental implants and subsequent restoration have always been the core focus of research. Sinus floor elevation and guided bone regeneration are worthy of constant exploration owing to their reliability. With continuous improvement in technology, immediate loading could become a future research hot spot.

Magnesium-doped Nanostructured Titanium Surface Modulates Macrophage-mediated Inflammatory Response for Ameliorative Osseointegration.

BACKGROUND: Next generation of coating materials on the surface of implants is designed with a paradigm shift from an inert material to an osteoimmunomodulatory material. Regulating immune response to biomedical implants through influencing the polarization of macrophage has been proven to be an effective strategy. METHODS: Through anodization and hydrothermal treatment, magnesium ion incorporated TiO2 nanotube array (MgN) coating was fabricated on the surface of titanium and it is hypothesized that it has osteoimmunomodulatory properties. To verify this assumption, systematic studies were carried out by in vitro and in vivo experiments. RESULTS: Mg ion release behavior results showed that MgN coating was successfully fabricated on the surface of titanium using anodization and hydrothermal technology. Scanning electron microscopy (SEM) images showed the morphology of the MgN coating on the titanium. The expression of inflammation-related genes (IL-6, IL-1ß, TNF-α) was downregulated in MgN group compared with TiO2 nanotube (NT) and blank Ti groups, but anti-inflammatory genes (IL-10 and IL-1ra) were remarkably upregulated in the MgN group. The in vitro and in vivo results demonstrated that MgN coating influenced macrophage polarization toward the M2 phenotype compared with NT and blank-Ti groups, which enhanced osteogenic differentiation of rat bone mesenchymal stem cells rBMSCs in conditioned media (CM) generated by macrophages. CONCLUSION: MgN coating on the titanium endowed the surface with immune-regulatory features and exerted an advantageous effect on osteogenesis, thereby providing excellent strategies for the surface modification of biomedical implants.

Current Trends in Research on Bone Regeneration: A Bibliometric Analysis.

BACKGROUND: Bone regeneration is a frequent research topic in clinical studies, but macroscopic studies on the clinical application of bone regeneration are rare. We conducted a bibliometric analysis, using international databases, to explore the clinical application and mechanism of bone regeneration, to highlight the relevant research hotspots and prospects. Material and Methods. Scientific reports on bone regeneration published during 2009-2019 were retrieved from PubMed. VOSviewer for cooccurrence keywords and authorship analysis. BICOMB software was used to retrieve high-frequency words and construct a text/coword matrix. The matrix was inputted into gCLUTO software, managed by biclustering analysis, in order to identify hotspots, which could achieve mountain and matrix visualizations. The matrix was also analyzed by using Ucinet 6 software for social network analysis. A strategic diagram was used for further analysis of the research hotspots of bone regeneration by "SCIMAT" software. We searched the Web of Science for relevant articles. RESULTS: Eighty-nine high-frequency major MeSH terms were obtained from 10237 articles and were divided into 5 clusters. We generated a network visualization map, an overlay visualization mountain map, and a social network diagram. Then, the MeSH terms were subdivided into 7 categories according to each diagram; current research hotspots were identified as scaffold, drug effect, osseointegration in dental implant, guided bone regeneration, factors impacting bone regeneration, treatment of bone and tissue loss, and bone regeneration in dental implants. CONCLUSION: BICOMB, VOSviewer, and other bibliometric tools revealed that dental implants, scaffolds, and factors impacting bone regeneration are hot research topics, while scaffolds also hold promise from the perspective of bone tissue regeneration.

LncRNA LINC00261 overexpression suppresses the growth and metastasis of lung cancer via regulating miR-1269a/FOXO1 axis.

BACKGROUND: LncRNAs are key regulators in cancer. The current study explored the role of lncRNA LINC00261 (LINC00261) in lung cancer (LC). METHODS: Expression of LINC00261 in LC tissues and cells was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Pearson's Chi square test and Kaplan-Meier analysis were performed to evaluate the correlations between LINC00261 expression and clinical characteristics, and overall survival time. A549 and SPC-A1 cells were transfected with LINC00261 overexpression plasmid, cell viability, cell number, and apoptosis were detected by CCK-8 assay, colony formation, and flow cytometry. Moreover, wound-healing and transwell assay were performed to detect cell metastasis and invasion. Expressions of proteins related to cell proliferation and metastasis were determined by Western blot. Xenograft was constructed, and tumor size and weight were measured and the effects of LINC00261 overexpression on tumor growth were detected. Bioinformatics analysis, dual-luciferase reporter assay, qRT-PCR, correlation analysis, and functional rescue experiments were conducted on clinical cases and LC cells to explore the molecular mechanism of LINC00261 in LC. RESULTS: In LC, LINC00261 expression was down-regulated, and was associated with more advanced TNM stage, metastasis and a shorter survival time. LINC00261 overexpression inhibited the growth and metastasis of LC cells in vitro and tumor growth in vivo. Furthermore, miR-1269a directly interacted with LINC00261 and FOXO1. The expressions of miR-1269a and FOXO1 were dysregulated by LINC00261 in LC. Additionally, miR-1269a promoted the progression of LC through targeting FOXO1. CONCLUSIONS: Down-regulation of LINC00261 expression has a prognostic value in LC, and overexpression LINC00261 inhibits LC progression via targeting miR-1269a/FOXO1 axis.

State of Osseointegrated Titanium Implant Surfaces in Topographical Aspect.

Titanium is a primary metallic biomaterial widely used in dental implants because of its favorable mechanical properties and osseointegration capability. Currently, increasing interests have been taken in the interaction between titanium implant surface and surrounding bone tissue, particularly in surface topographical aspect. There are currently several techniques developed to modify surface topographies in the world market of dental implant. In this review, state of titanium implant surfaces in topographical aspect is presented from relatively smooth surfaces to rougher ones with microtopographies and/or nanotopographies. Each surface is summarized with basic elaborations, preparation methods, mechanisms for cellular responses and current availabilities. It has been demonstrated that rough surfaces evolving from micro- to nano-scale, especially hierarchical micro-and nanotopographies, are favorable for faster and stronger osseointegration. Further experimental and clinical investigations will aid in the optimization of surface topography and clinical selection of suitable implants.

Tuning the size of supramolecular M4L4 tetrahedra by ligand connectivity.

Triangular triscatechol ligands are prepared in facile reaction sequences. The catechol units are either bound to the triangular backbone through their 3- or 4-position. With titanium(IV) ions, the ligands form metallosupramolecular M(4)L(4) tetrahedra which are characterized by ESI MS and proton NMR. Quantum-chemical calculations reveal that connectivity at the catechol in the 3-position results in highly condensed structures while attachment in the 4-position affords container molecules providing huge internal cavities.