Comparison of small extracellular vesicles derived from stem cells and tissue on de novo adipose regeneration / 中国组织工程研究

BACKGROUND:De novo adipose regeneration induced by small extracellular vesicles has become a promising method for repairing soft tissue defects.However,due to different animal models and small extracellular vesicle application dosages,it is difficult to quantitatively compare the therapeutic effect of small extracellular vesicles from various sources on adipose regeneration. OBJECTIVE:To compare the regenerative effects of small extracellular vesicles derived from stem cells and small extracellular vesicles from tissue. METHODS:Small extracellular vesicles derived from adipose-derived stem cells and from adipose tissue were isolated by ultracentrifugation.The particle number,particle size,morphology,and protein expression of small extracellular vesicles were identified by nanoparticle tracking analysis,transmission electron microscopy and western blot assay.A quantitative and evaluative subcutaneous model for adipose regeneration in C57 mice was established using a customized silicone tube.The regenerative effects of induced de novo adipose were compared by cell counting and hematoxylin-eosin staining. RESULTS AND CONCLUSION:(1)Small extracellular vesicles derived from adipose-derived stem cells and from adipose tissue were isolated by ultracentrifugation.Both small extracellular vesicles were round-shape in transmission electron microscopy with particle size between 50-200 nm,and abundant with the small extracellular vesicles marker protein CD81,CD63 and TSG101.(2)An equal number of small extracellular vesicles were mixed with matrigel in customized silicone tubes,implanted subcutaneously in the back of mice to establish a cell-free and quantifiable adipose regeneration model.(3)On days 3 and 7 after implantation,the results of cell counting and hematoxylin-eosin staining showed that both small extracellular vesicle groups recruited more host cells than the blank group,and the small extracellular vesicles derived from adipose tissue group were superior to the small extracellular vesicles derived from adipose-derived stem cell group.(4)4 weeks after implantation,hematoxylin-eosin staining of the contents in silicone tubes showed that small extracellular vesicles induced de novo adipose regeneration in vivo,and the small extracellular vesicles derived from adipose tissue group were superior to the small extracellular vesicles derived from adipose-derived stem cell group.The above results indicated that small extracellular vesicles derived from tissues have a superior effect on inducing de novo adipose regeneration compared to small extracellular vesicles derived from stem cells.

Application of cell derivative in periodontal regeneration / 中国组织工程研究

BACKGROUND:Cell derivative is cell-derived bioactive components,including decellularized extracellular matrix,exosome,apoptotic extracellular vesicle,and conditioned medium,has the effects on immune regulation,promoting angiogenesis,bone regeneration,ligament remodeling,and is capable of promoting stem cell chemotherapy,migration,proliferation,and adhesion.Its excellent characteristics make it a promising biomaterial for application and clinical translation in the field of periodontal tissue engineering. OBJECTIVE:To review the characteristics of cell derivatives(decellularized extracellular matrix,exosome,apoptotic extracellular vesicle,and conditioned medium)and its effect and the latest progress in the field of regenerative restoration of periodontal complex tissue structures. METHODS:We searched the articles on CNKI and PubMed databases with the search terms"regeneration,periodontal tissue,tissue engineering,decellularized matrix,exosome,apoptotic extracellular vesicle,condition medium"in Chinese and English,respectively.Finally,76 articles were included for analysis and discussion. RESULTS AND CONCLUSION:(1)Among those four cell derivatives,the decellularized extracellular matrix has the best mechanical properties and fibrous structure,serving as a biomimetic scaffold to provide physiochemical signals and participate in mechanical signaling in periodontal tissue engineering,providing supporting effect suitable for periodontal regeneration.Recently,the development of soluble decellularized extracellular matrix bioinks has enabled the fabrication of regenerative scaffolds for personalized periodontal defects.(2)Exosomes are the simplest cell derivatives that have immunomodulatory capacity,promoting cell migration and differentiation.As a carrier,they can be used to carry target molecules to regulate periodontal regeneration,promote ligament remodeling and bone regeneration,and are suitable for periodontal tissue engineering.(3)Apoptotic vesicles generated from apoptotic cells have a strong immunomodulatory effect and can recruit stem cells and macrophages,which determine the fate of stem cells through signal transduction and can enhance immunomodulation to promote periodontal regeneration.Engineered extracellular vesicle is considered to have the potential to initiate targeted internal immunomodulation.(4)The extraction of conditioned medium is simple and completely noninvasive,which provides essential nutrients and growth factors for tissue regeneration.These components are crucial for successful periodontal regeneration.Therefore,the conditioned medium is especially suitable for studying the interactions between cells in vitro and has an important role in high-throughput detection in the future.

A survey on iodine nutrition status of pregnant women in Wuhan from 2016 to 2020 / 中华地方病学杂志

Objective:To understand the iodine nutrition status of pregnant women in Wuhan, and to provide a basis for guiding pregnant women to supplement iodine scientifically and adjust the prevention and control strategy of iodine deficiency disorders.Methods:From May 2016 to September 2020, each district of 13 administrative districts in Wuhan was divided into 5 areas according to east, west, south, north and middle. One township (street) was selected from each area, and 20 pregnant women were selected from each township (street). Edible salt and urine samples were collected to detect the contents of salt iodine and urinary iodine. Salt iodine was determined by direct titration, Sichuan salt and other fortified edible salt by arbitration method; urinary iodine was detected by arsenic-cerium catalytic spectrophotometry. Salt iodine and urinary iodine were analyzed according to different years, regions (central and far urban areas), age [low age (< 25 years old), appropriate age (25 - 34 years old), old age (≥35 years old)], and pregnancy [early pregnancy (< 13 weeks), middle pregnancy (13 - 27 weeks), and late pregnancy (28 - 40 weeks)].Results:A total of 5 200 edible salt samples from pregnant women's homes were collected, and the median salt iodine was 24.41 mg/kg. Among them, there were 32 non-iodized salts, 4 962 qualified iodized salts, and 206 unqualified iodized salts. The coverage rate of iodized salt was 99.38% (5 168/5 200), and the consumption rate of qualified iodized salt was 95.42% (4 962/5 200). A total of 5 200 pregnant women's urine samples were tested, and the median urinary iodine was 161.24 μg/L. Urinary iodine < 150 μg/L was found in central urban area, early pregnancy, middle pregnancy, low age and old age pregnant women in 2016 (141.74, 149.00, 132.34, 135.17, 121.00 μg/L); in early pregnancy, middle pregnancy and old age pregnant women in 2017 (128.00, 149.00, 141.41 μg/L); and in middle pregnancy and old age pregnant women in 2020 (148.95, 138.00 μg/L), which was at iodine deficiency level.Conclusions:Pregnant women in Wuhan are generally at iodine appropriate level, but close to the lower limit of the appropriate value, some pregnant women are at risk of iodine deficiency. It is still necessary to pay close attention to iodine nutrition status of pregnant women, and advocate pregnant women to eat qualified iodized salt actively.

Bone morphogenetic protein 7 mediates stem cells migration and angiogenesis: therapeutic potential for endogenous pulp regeneration / 国际口腔科学杂志·英文版

Pulp loss is accompanied by the functional impairment of defense, sensory, and nutrition supply. The approach based on endogenous stem cells is a potential strategy for pulp regeneration. However, endogenous stem cell sources, exogenous regenerative signals, and neovascularization are major difficulties for pulp regeneration based on endogenous stem cells. Therefore, the purpose of our research is to seek an effective cytokines delivery strategy and bioactive materials to reestablish an ideal regenerative microenvironment for pulp regeneration. In in vitro study, we investigated the effects of Wnt3a, transforming growth factor-beta 1, and bone morphogenetic protein 7 (BMP7) on human dental pulp stem cells (h-DPSCs) and human umbilical vein endothelial cells. 2D and 3D culture systems based on collagen gel, matrigel, and gelatin methacryloyl were fabricated to evaluate the morphology and viability of h-DPSCs. In in vivo study, an ectopic nude mouse model and an in situ beagle dog model were established to investigate the possibility of pulp regeneration by implanting collagen gel loading BMP7. We concluded that BMP7 promoted the migration and odontogenic differentiation of h-DPSCs and vessel formation. Collagen gel maintained the cell adhesion, cell spreading, and cell viability of h-DPSCs in 2D or 3D culture. The transplantation of collagen gel loading BMP7 induced vascularized pulp-like tissue regeneration in vivo. The injectable approach based on collagen gel loading BMP7 might exert promising therapeutic application in endogenous pulp regeneration.

The Role of Sphingolipid Metabolism in Bone Remodeling.

Emerging studies of bioactive lipids have made many exciting discoveries in recent years. Sphingolipids and their metabolites perform a wide variety of cellular functions beyond energy metabolism. Emerging evidence based on genetically manipulated mouse models and molecular biology allows us to obtain new insights into the role sphingolipid played on skeletal remodeling. This review summarizes studies or understandings of the crosstalk between sphingomyelin, ceramide, and sphingosine-1-phosphate (S1P) of sphingolipids family and the cells, especially osteoblasts and osteoclasts of the bone through which bone is remodeled during life constantly. This review also shows agonists and antagonists of S1P as possible therapeutic options and opportunities on bone diseases.

Wnt5a up-regulates Periostin through CaMKII pathway to influence periodontal tissue destruction in early periodontitis.

Periostin is essential for periodontal tissue integrity and homeostasis and also associated with periodontitis and periodontitis healing. This study aims to investigate the temporal and spatial expression of Periostin and Wnt5a/CaMKII in periodontitis and how the Wnt5a regulates Periostin through CaMKII signaling pathway in PDLCs in inflammatory environment. The experimental periodontitis mice were adopted to clarify the temporal and spatial expression of Wnt5a, CaMKII and Periostin during early periodontitis. And the Wnt5a, CaMKII and Periostin expression pattern and regulation mechanism in PDLCs were clarified in Porphyromonas gingivalis Lipopolysaccharide (P.g. LPS) induced inflammatory condition. Along with the periodontitis development, Wnt5a, CaMKII and Periostin significantly increased in periodontal ligament and partially increased in gingiva during 0 to 6 day (P < 0.05). They were involved in early periodontitis homeostasis especially in periodontal ligament tissue. Meanwhile, Wnt5a, CaMKII and Periostin were significantly decreased at 12 h (P < 0.05) and increased at 48 h (P < 0.05) in PDLCs after induced by P.g. LPS. Besides, Wnt5a significantly enhanced total CaMKII protein (P < 0.05), pCaMKII (P < 0.001) and Periostin (P < 0.001), and this could be blocked by CaMKII inhibitor KN93 (P < 0.05). In conclusions, in early periodontitis, Wnt5a/CaMKII and Periostin should be involved in maintaining periodontal homeostasis and Wnt5a could up-regulate Periostin via CaMKII pathway in inflammation, which would provide new clues for us to understand the pathogenesis of periodontitis and develop better therapeutic strategies.

Enhanced effects of electrospun collagen-chitosan nanofiber membranes on guided bone regeneration.

It was aim to study the physicochemical features and biocompatibility of electrospun collagen-chitosan membranes, and its potential in guided bone regeneration. Electrospinning technology was applied in the fabrication of electrospun collagen membranes and electrospun collagen-chitosan membranes following observation of scanning electron microscope. Physicochemical properties including tensile strength, elongation rate, porosity, degradation rate, and biocompatibility of membranes were measured then. In vivo, calvarial bone defects created on rats were covered with two kinds of membranes respectively. In the 4th and 8th week, enzyme-linked immunosorbent assay testing bone alkaline phosphatase and osteocalcin, Micro CT analyzing bone volume, bone volume/total volume, trabecular number and trabecular spacing values, and histological staining were carried out for evaluating the potentials of the membranes on bone regeneration. We found that regular and highly-porous structure favoring the adhesion and proliferation of periodontal ligament cells was observed in all electrospinning groups. Compared with electrospun collagen membranes, electrospun collagen-chitosan membranes performed better physiochemical features including higher tensile strength and more stable degradation rate. In the animal model, compared with the other groups, higher levels of bone alkaline phosphatase in the 4th week and osteocalcin in the 8th week were observed in the electrospun collagen-chitosan membrane. Meanwhile, both of the radiographical and histological results further confirmed that the new bone formation (with higher bone volume, bone volume/total volume, Trabecular number, and lower Trabecular spacing) were more active in the electrospun collagen-chitosan membrane. In conclusion, Electrospun collagen-chitosan membranes perform excellent physicochemical properties, biocompatibility, and great effects on guided bone regeneration, which as the membrane has good application prospect in tissue regeneration.

Risk factors for cerebrospinal fluid fistulas due to endoscopic transnasal surgery for pituitary neoplasms / 中华神经医学杂志

Objective To investigate the risk factors associated with cerebrospinal fluid (CSF) fistulas due to endoscopic transnasal surgery for pituitary neoplasms.Methods The data of 1,063patients were reviewed who had undergone transnasal surgery for pituitary adenomas between January 2009 and December 2012 at Department of Neurosurgery,General Hospital of PLA in Beijing.Intra-operative CSF fistulas were observed in 122 patients but not in the other 941 ones;post-operative CSF fistulas were observed in 29 patients but not in the other 1,034 ones.The clinical data were compared between the patients with and without intra-operative CSF fistulas and between those with and without post-operative CSF fistulas.Chi-square was used to identify the potential risk factors associated with intra-and post-operative CSF fistulas.Multivariate Logistic analysis was performed for correlated variables.Results There was a significant difference in tumor size between the patients with and without intra-operative CSF fistulas (P＜0.05).There were significantly more patients undergoing reoperation in those with intra-operative CSF fistulas than in those without (P＜0.05).The multivariate Logistic analysis revealed that giant adenoma,macroadenoma and reoperation were independently associated with intraoperative CSF fistulas.There was a significant difference in age and tumor size between the patients with and without post-operative CSF fistulas (P＜0.05).There were significantly more patients undergoing reoperation and suffering intraoperative CSF fistulas in those with post-operative CSF fistulas than in those without (P＜0.05).The multivariate Logistic analysis revealed that giant pituitary neoplasms,reoperation and intra-operative CSF fistulas were independently associated with post-operative CSF fistulas.Conclusions In endoscopic transnasal surgery for pituitary neoplasms,the risk factors for intra-operative CSF fistulas are larger tumor size and reoperation and the risk factors for post-operative CSF fistulas are giant pituitary neoplasms,intra-operative CSF fistulas and reoperation.

Development of new technology in periodontal tissue engineering / 中华口腔医学杂志

The loss of periodontal support tissues might cause movement or finally loss of the teeth affected, impair furthermore the pronunciation and mastication functions, and even result in a series of physiological and psychological problems. Tissue engineering, as a technology to remodel missing tissues or organs and functional reconstruction, has achieved gratifying progress in regeneration of periodontal tissues. However, conventional construction methods have some deficiencies for functional periodontal reconstruction. In recent years, with the progress of tissue engineering technology, a series of new techniques and methods, such as cell sheet technology, decellular technology, electrospinning technology and three-dimensional printing, has been applied in tissue engineering bringing new hope for the regeneration of periodontal tissues. In this review article, the recent progress achieved in the field of periodontal tissue engineering and application of modern technology are summarized to make a brief exposition and to explore the future development of periodontal regeneration.

[Effect of hypoxia on the biological characteristics of human dental follicle cells].

OBJECTIVE: This study aimed to investigate the effects of hypoxia on the characteristics of human dental follicle cells (hDFCs). METHODS: The tissue explant collagenase method was used to isolate hDFCs from young permanent teeth. The immunofluorescence technique was used to detect cell surface markers, and the multi-differentiation potential was detected by multilineage differentiation induction assay. Then, the hypoxic microenvironment was physically mimicked, and the cells were divided into the normoxia group (20%O2) and the hypoxia group (2%O2). The effects of hypoxia on cell migration and proliferation were examined by Transwell chamber test and CCK-8 assay, respectively. The gene and protein expression levels of stemness-related markers at both oxygen concentrations were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. After osteogenic induction of both groups, qRT-PCR was performed to evaluate the osteogenesis-related gene, and alizarin red staining was used to assess the formation of mineralized nodules. RESULTS: With the multi-differentiation capacity of osteogenic cells, adipogenic cells, and nerves, hDFCs demonstrate strong stem cell characteristics and possess the criteria of mesenchymal stem cells, which can meet the requirements of seed cells in dental tissue engineering. Hypoxia was conducive to the maintenance of hDFC stemness. Hypoxia promoted the migration and proliferation of hDFCs. The hDFCs were induced to osteogenic differentiation under hypoxic conditions, thereby enhancing osteogenesis. CONCLUSIONS: Hypoxic microenvironment plays an important role in maintaining the stemness and promoting the proliferation, migration, and differentiation of hDFCs. Thus, this microenvironment could also serve several important functions in future clinical applications.

Tooth and its supporting tissues regeneration using functional tooth modules / 中华口腔医学杂志

Stem cell based generation of functional tissue modules is becoming a hotspot in the field of tissue regeneration. These functional tissue modules, which can be prepared through a variety of ways, including self-organization of stem cells, cell sheets, electrospinning and bio-printing, can serve as the basic unit and be assembled to form larger tissues and organs. This new technology can be a break-through to address current issues in tissue regeneration and further promote the translational use of regenerated tissues/organs. Construction of functional tooth modules is still in its early stage, where the stem cell source, preparing method and strategy of translational use are not clearly defined yet. How to construct the functional tissue module through the existing technology still needs further study. Here, we would like to share our current understanding and thoughts on constructing strategies and potential clinical application of functional tooth modules including dental pulp, periodontal tissue and tooth root, and hope it could shed new lights on the regeneration of tooth.

[Treated dentin matrix enhances proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells].

OBJECTIVE: The effect of treated dentin matrix (TDM) to the proliferation and osteogenesis differentiation of bone marrow mesenchymal stem cells (BMSCs) is evaluated in vitro. METHODS: TDM leaching solution was prepared by dentine particles suffering from gradient demineralization. Human BMSCs were isolated and cultivated, and subsequently cultivated in the TDM leaching solution. The proliferation of BMSCs was detected by CCK-8. The osteogenesis-related proteins, including collagen type I (Col I) and runt-related transcription factor-2 (Runx2), were extracted and detected by Western blot after a 7-day culture. RESULTS: Compared with the control group and hydroxyapatite (HA)/ß-tricalcium phosphate (ßTCP) group, the proliferation of BMSCs cultivated in TDM leaching solution was significantly improved. The expression of Col I and Runx2 obviously increased after the 7-day cultivation in TDM leaching solution. CONCLUSION: TDM can promote the proliferation and osteogenesis differentiation of BMSCs, implying the feasibility of the application in bone tissue engineering.

[Expression and effect of S100A9 in the periodontium of diabetic rats].

OBJECTIVE: The study seeks to investigate the expression of S100A9 and its potential role in periodontal diseases induced by diabetes. METHODS: A diabetic SD rat model was established through intraperitoneal injection of streptozotocin (STZ). Hematoxylin-eosin (HE) staining was performed to study the structure of the periodontium of diabetic rats. Using immunohistochemical staining, the distribution of S100A9 expression was detected in the periodontium of diabetic rats. Ex-pressions of Toll-like receptor 4 (TLR4) (ligands of S100A9) and p-P65/nuclear factor κB (NF-κB) were also measured. RESULTS: The trabecular structure of alveolar bone was sparser, and lamina dura was disappeared in diabetic rats. Obviously higher expressions of S100A9 were observed in the periodontal ligament, alveolar bone, and gingival epithelial of diabetic rats than in the control rats. TLR4 expressions in the periodontal ligament, alveolar bone and gingival epithelial of the diabetic rats were also higher as compared to the control rats. p-P65 expression was not detected in the control rats, but was detected in the periodontal ligament and alveolar bone of the diabetic rats. CONCLUSIONS: Periodontium lesions in diabetes mellitus may be induced by the activation of TLR4 and NF-κB signaling pathway meditated by S100A9. 
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Treated dentin matrix enhances proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The effect of treated dentin matrix (TDM) to the proliferation and osteogenesis differentiation of bone marrow mesenchymal stem cells (BMSCs) is evaluated in vitro.</p><p><b>METHODS</b>TDM leaching solution was prepared by dentine particles suffering from gradient demineralization. Human BMSCs were isolated and cultivated, and subsequently cultivated in the TDM leaching solution. The proliferation of BMSCs was detected by CCK-8. The osteogenesis-related proteins, including collagen type I (Col I) and runt-related transcription factor-2 (Runx2), were extracted and detected by Western blot after a 7-day culture.</p><p><b>RESULTS</b>Compared with the control group and hydroxyapatite (HA)/β-tricalcium phosphate (βTCP) group, the proliferation of BMSCs cultivated in TDM leaching solution was significantly improved. The expression of Col I and Runx2 obviously increased after the 7-day cultivation in TDM leaching solution.</p><p><b>CONCLUSION</b>TDM can promote the proliferation and osteogenesis differentiation of BMSCs, implying the feasibility of the application in bone tissue engineering.</p>

[Effects of different fibrin glue combination modes on the proliferation and viability of dental follicle cells].

OBJECTIVE: This study explores the effects of different fibrin glue combination modes on the survival, proliferation, and apoptosis of dental follicle cells (DFCs), as well as to evaluate the feasibility and effectiveness of fibrin glue as transplantation material. METHODS: The membranes of surviving DFCs were marked using 3,3'-dioctadecyloxa carbocyanine perchlorate (DIO), and the cell number was counted by using ImageJ2x software. The apoptotic cells were marked with prodium iodide (PI). RESULTS: Compared with that of the 3D-2 and 2D-1 groups, the degradation speed of the 3D-1 group was the slowest. DFCs could survive and grow well in fibrinogen with a concentration of 15 mg · mL⁻¹ supplemented with thrombin with a concentration of 2 U · mL⁻¹. In particular, the 3D-1 combination mode was significantly conducive to cell proliferation and stretching. CONCLUSION: Fibrin glue can be used as an effective cell transplantation material. The different combination modes have certain effects on cell proliferation. The 3D-1 combination mode is more conducive to the survival and proliferation of DFCs than other modes.

[Corrosion resistant properties of different anodized microtopographies on titanium surfaces].

OBJECTIVE: To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. METHODS: Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. RESULTS: Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. CONCLUSION: Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.

Corrosion resistant properties of different anodized microtopographies on titanium surfaces / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies.</p><p><b>METHODS</b>Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid.</p><p><b>RESULTS</b>Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr.</p><p><b>CONCLUSION</b>Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.</p>

Effects of different fibrin glue combination modes on the proliferation and viability of dental follicle cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study explores the effects of different fibrin glue combination modes on the survival, proliferation, and apoptosis of dental follicle cells (DFCs), as well as to evaluate the feasibility and effectiveness of fibrin glue as transplantation material.</p><p><b>METHODS</b>The membranes of surviving DFCs were marked using 3,3'-dioctadecyloxa carbocyanine perchlorate (DIO), and the cell number was counted by using ImageJ2x software. The apoptotic cells were marked with prodium iodide (PI).</p><p><b>RESULTS</b>Compared with that of the 3D-2 and 2D-1 groups, the degradation speed of the 3D-1 group was the slowest. DFCs could survive and grow well in fibrinogen with a concentration of 15 mg · mL⁻¹ supplemented with thrombin with a concentration of 2 U · mL⁻¹. In particular, the 3D-1 combination mode was significantly conducive to cell proliferation and stretching.</p><p><b>CONCLUSION</b>Fibrin glue can be used as an effective cell transplantation material. The different combination modes have certain effects on cell proliferation. The 3D-1 combination mode is more conducive to the survival and proliferation of DFCs than other modes.</p>

Biomechanical evaluation and optimal design of two parameters of dental implant with arbitrarily adjusted angles / 中国组织工程研究

BACKGROUND:Oversize stress of a dental implant and its surrounding tissue is the main factor to affect the long-term use of dental implants. So, the reasonable and precise design of implant shape is one of the important methods of prolonging the life span of dental implants. OBJECTIVE:To make the optimal analysis and design of the diameters of connector screw and central screw of the adjustable-angle dental implant invented in the earlier stage. METHODS: The finite element analysis model of the edentulous mandible with adjustable-angle dental implant was established by software Pro/E 5.0, Mimics 10.0 and ANSYS Workbench 14.5. The maximum equivalent stress of dental implant-edentulous mandibular model was analyzed. RESULTS AND CONCLUSION:The maximum equivalent stress of dental implant-edentulous mandibular model

Platelet-rich plasma effects on grainy fat transplantation / 中国组织工程研究

BACKGROUND:The higher long-term absorption rate greatly influence the widely application of fat transplantation. Platelet-rich plasma contains a high concentration of growth factors, which benefits to the tissue healing and regeneration. OBJECTIVE:To observe the effects of platelet-rich plasma on grainy fat transplantation and to investigate the mechanisms preliminarily. METHODS:Ten 6-week-old nude mice were prepared. The right or left dorsal subcutaneous tissues were randomly selected as the platelet-rich plasma group (0.5 mL fat granule+0.1 mL platelet-rich plasma), and the contralateral side was regarded as the control group (0.5 mL fat granule+0.1 mL phosphate-buffered saline). At 10 and 90 days after implantation, five nude mice were selected from each group, and then the mice were sacrificed to obtain the grafts in each group for general appearance observation, volume determination and histological detection. Furthermore, we isolated adipose-derived stem cells from human subcutaneous fat tissue during the in vitro experiment. Cel counting kit-8 and real-time PCR were used to evaluate the influence of platelet-rich plasma on adipose-derived stem cel proliferation and adipogenic differentiation in vitro, respectively. RESULTS AND CONCLUSION:Comparison of the grafts obtained at 10 and 90 days after implantation, the residual volume in the platelet-rich plasma group was significantly larger than that in the control group (P<0.05), Moreover, more normal adipocytes and capil ary formation were observed in the platelet-rich plasma group (P<0.05). For in vitro experiment, platelet-rich plasma could significantly improve adipose-derived stem cel proliferation, and the expressions of adipogenic-related genes were up-regulated in platelet-rich plasma-induced adipose-derived stem cells. Al results demonstrate that platelet-rich plasma can improve the survival of fat grafts,which might be closely related to that platelet-rich plasma can promote the proliferation and adipogenic differentiation of adipose-derived stem cells and the revascularization in grafted fat tissue.