Comparison of implantation accuracy among different navigated approaches: A systematic review and network meta-analysis.

PURPOSE: Dental implants are a common method for the treatment of tooth loss, and its accuracy directly affects forward efficacy and stability. This study compared the accuracy of different modalities of dental implant placement (dynamic navigation [DN], fully guided [FG] static navigation, partially guided [PG] static navigation, and free handed [FH]) through a network meta-analysis. MATERIALS AND METHODS: This study followed the Preferred Reporting Items for Meta-Analyses (PRISMA) guidelines and conducted an electronic literature search (Inception-Oct 2, 2022). The comparison of implant accuracy in all the included randomized controlled trials (RCTs) conformed to at least one of the following: deviation at the crown of the implant, deviation at the apical portion of the implant, or angular deviation of the implant. RESULTS: Twenty-six articles were included for the qualitative analysis (17 RCTs; 3 prospective studies; 6 retrospective studies), and 17 RCTs of which were included for network meta-analysis. The data included in this study had high consistency, and the funnel plot showed that the articles had low publication bias. Compared with FH, FG and DN had higher accuracy in coronal deviation (P<0.05), and FG, DN, and PG had higher accuracy in apical deviation and angular deviation (P<0.05). According to the SUCRA value, FG had the highest accuracy in coronal deviation, while DN had the highest accuracy in apical deviation and angular deviation. CONCLUSIONS: According to the results of this literature review, the accuracy of DN, FG, and PG were higher than those of FH. DN showed the highest accuracy in terms of apical deviation and angular deviation. FG had the best control over the coronal deviation. There was no statistical difference between DN and FG in terms of accuracy. Given the limitations of the current study, further validation is required in the future.

Lactobacillus treatment as adjuvant for geographic tongue and fissured tongue with gastritis: case report.

Background: Geographic tongue and fissured tongue are both common oral mucous membrane diseases relatively. The treatment of this disease is typically causative therapy because of the unknown etiology, and other afflictions. Gastrointestinal disease is one of the factors that induce geographic tongue with a fissured tongue. As an adjuvant drug that can inhibit the growth of Helicobacter pylori, the most common pathogen of chronic gastritis, Lactobacillus is widely used in clinic. However, there are seldom studies about Lactobacillus used in the treatment of geographic tongue and fissured tongue. Therefore, this case we used typically causative therapy with Lactobacillus as adjuvant to treat patient with a geographic tongue and fissured tongue with gastrointestinal disease and explore the effectiveness for further application. Case Description: A 33-year-old female patient presented with a geographic tongue and fissured tongue with dysgeusia. At the first visit, there were smooth red lesions on the back of the tongue with the hyperplasia of the surrounding filiform papilla. The cracks in the middle of the tongue had a crack of about 2.5 cm long and 0.8 cm deep, and 5-6 light cracks on the tip of the tongue. The patient reported a history of chronic gastritis for 1 year, often with soft stool and gastroesophageal reflux disease. We administered drug treatment, including sodium bicarbonate tablets, Kangfuxin solution, compound chlorhexidine solution, and stomatitis spray. In addition, we suggested the patient use a yogurt machine to make and drink fresh yogurt with Lactobacillus as adjuvant everyday day and suggested a daily regimen of a light diet with no stimulating food, regular work, and sufficient rest. Ten days after the first visit, the symptoms were obviously alleviated. Twenty days after the initial diagnosis, the geographic tongue lesions had disappeared and the cracks had basically healed. The patient reported that the gastric symptoms had improved, and there was no soft stool or stomach discomfort. Conclusions: This study used Lactobacillus as the adjuvant with typically causative therapy in the treatment of geographic tongue and fissured tongue.

The 3D-Printed Ordered Bredigite Scaffold Promotes Pro-Healing of Critical-Sized Bone Defects by Regulating Macrophage Polarization.

Background: Repairing critical-sized bone defects secondary to traumatic or tumorous damage is a complex conundrum in clinical practice; in this case, artificial scaffolds exhibited preferable outcomes. Bredigite (BRT, Ca7MgSi4O16) bioceramic possesses excellent physicochemical properties and biological activity as a promising candidate for bone tissue engineering. Methods: Structurally ordered BRT (BRT-O) scaffolds were fabricated by a three-dimensional (3D) printing technique, and the random BRT (BRT-R) scaffolds and clinically available ß-tricalcium phosphate (ß-TCP) scaffolds were compared as control groups. Their physicochemical properties were characterized, and RAW 264.7 cells, bone marrow mesenchymal stem cells (BMSCs), and rat cranial critical-sized bone defect models were utilized for evaluating macrophage polarization and bone regeneration. Results: The BRT-O scaffolds exhibited regular morphology and homogeneous porosity. In addition, the BRT-O scaffolds released higher concentrations of ionic products based on coordinated biodegradability than the ß-TCP scaffolds. In vitro, the BRT-O scaffolds facilitated RWA264.7 cells polarization to pro-healing M2 macrophage phenotype, whereas the BRT-R and ß-TCP scaffolds stimulated more pro-inflammatory M1-type macrophages. A conditioned medium derived from macrophages seeding on the BRT-O scaffolds notably promoted the osteogenic lineage differentiation of BMSCs in vitro. The cell migration ability of BMSCs was significantly enhanced under the BRT-O-induced immune microenvironment. Moreover, in rat cranial critical-sized bone defect models, the BRT-O scaffolds group promoted new bone formation with a higher proportion of M2-type macrophage infiltration and expression of osteogenesis-related markers. Therefore, in vivo, BRT-O scaffolds play immunomodulatory roles in promoting critical-sized bone defects by enhancing the polarization of M2 macrophages. Conclusion: 3D-printed BRT-O scaffolds can be a promising option for bone tissue engineering, at least partly through macrophage polarization and osteoimmunomodulation.

Hierarchical Intrafibrillarly Mineralized Collagen Membrane Promotes Guided Bone Regeneration and Regulates M2 Macrophage Polarization.

Mineralized collagen has been introduced as a promising barrier membrane material for guided bone regeneration (GBR) due to its biomimetic nanostructure. Immune interaction between materials and host significantly influences the outcome of GBR. However, current barrier membranes are insufficient for clinical application due to limited mechanical or osteoimmunomodulatory properties. In this study, we fabricated hierarchical intrafibrillarly mineralized collagen (HIMC) membrane, comparing with collagen (COL) and extrafibrillarly mineralized collagen (EMC) membranes, HIMC membrane exhibited preferable physicochemical properties by mimicking the nanostructure of natural bone. Bone marrow mesenchymal stem cells (BMSCs) seeded on HIMC membrane showed superior proliferation, adhesion, and osteogenic differentiation capacity. HIMC membrane induced CD206+Arg-1+ M2 macrophage polarization, which in turn promoted more BMSCs migration. In rat skull defects, HIMC membrane promoted the regeneration of new bone with more bone mass and more mature bone architecture. The expression levels of Runx2 and osterix and CD68 + CD206 + M2 macrophage polarization were significantly enhanced. HIMC membrane provides an appropriate osteoimmune microenvironment to promote GBR and represents a promising material for further clinical application.

Inhibition of the negative effect of high glucose on osteogenic differentiation of bone marrow stromal cells by silicon ions from calcium silicate bioceramics.

Human bone marrow stem cells (hBMSCs) are exploited for miscellaneous applications in bone tissue engineering where they are mainly used as seed cells. However, high glucose (HG) environment has negative impacts on the proliferation and osteogenic differentiation of hBMSCs, thus reducing the bone formation in diabetic patients. In our former research works, we discovered that silicon (Si) ions extracted from silicate-based bioceramics are able to stimulate the proliferation and osteogenic differentiation of hBMSCs under normal culture condition. This study aimed to investigate if Si ions could prevent HG-induced inhibition of proliferation and osteogenesis of hBMSCs. We found that 2.59 ppm concentration of Si ions promoted the proliferation of hBMSCs under HG condition. The results from alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time PCR analysis of osteogenic genes (BMP2, RUNX2, ALP, COL1 and OCN) demonstrated that the 15.92 ppm concentration of Si ions prevented HG-induced inhibition of the osteogenic differentiation of hBMSCs. Moreover, application of Si ions reduced the level of reactive oxygen species in HG-treated hBMSCs. In HG-treated hBMSCs following 15.92 ppm Si ions treatment, activation of BMP2/SMAD signaling pathway was detected, as indicated by the increased expression of BMP2 receptors and its downstream genes such as SMAD1, SMAD4 and SMAD5. Taken together, we provide evidence that the specific concentration of Si ions compensated HG-induced inhibition of proliferation and osteogenic differentiation of hBMSCs through antioxidant effect and modulation of BMP2/SMAD pathway. The results suggest that silicate-based bioceramics might be good scaffold biomaterials for bone engineering applications in diabetes patients.

Soft X-ray-Enhanced Reactive Oxygen Species Generation in Mesoporous Titanium Peroxide and the Application in Tumor Synergistic Therapy.

Mesoporous titanium peroxide TiOx nanospheres with a high surface area are synthesized for the application of an advanced drug system. The mesoporous TiOx nanospheres have a high specific surface area of 681.89 m2/g and suitable pore size (∼3 nm) that can effectively upload doxorubicin (DOX) and possesses a high drug storage capacity of 146.08%. They show a distinct ability to produce reactive oxygen species (ROS) in response to X-ray irradiation, which can effectively improve the radiotherapy in tumor treatment using the lung cancer cell line. The ROS generation of TiOx is more than ten-fold higher than that of TiO2. No apparent toxicity is found for the TiOx material itself without X-ray irradiation. In vitro and in vivo experiments show that TiOx/DOX nanodrugs significantly enhance cytotoxicity in response to X-ray irradiation. CCK8 assays display that the TiOx/DOX nanodrug has higher cancer treatment efficiency in response to X-ray irradiation because of the synergistic effect of chemotherapy and generation of ROS. In the in vivo experiments using lung cancer tumor-bearing mice model, the tumor inhibition rate in the TiOx/DOX + X-ray group increased by 90.4% compared to the untreated control group, showing a good synergistic chemo-radiotherapy effect in tumor treatment.

CKIP-1 regulates the immunomodulatory function of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are self-renewing multipotent cells with immunoregulatory function, which makes them attractive candidates for regenerative medicine. However, the detailed mechanisms of their immunomodulatory capacity are not fully characterized. Here, we found that casein kinase 2 interacting protein-1 (CKIP-1) expression was induced in the murine MSC cell line C3H/10T1/2 by LPS. Knockdown of CKIP-1 did not cause significant differences on the cell cycle or immunophenotype of MSCs. However, MSCs with CKIP-1 knockdown showed enhanced immunosuppressive capacity. Real-time PCR and western blot analyses revealed that compared with the control group, MSCs with CKIP-1-knockdown exhibited higher IL-10 production and p38 MAPK phosphorylation following LPS treatment. Interestingly, the expression of CKIP-1 was decreased in MSCs following high glucose treatment. Furthermore, MSCs became more immunosuppressive after high glucose treatment, as shown by higher IL-10 production and enhanced inhibition of T cell proliferation. Collectively, our data reveal a novel role for CKIP-1 in regulating MSC-mediated immunomodulation, and indicate that MSCs become more immunosuppressive under high glucose conditions. These new insights may help in the development of future applications of MSCs.

Sudden sensorineural hearing loss (SSHL) following a local anesthetic dental procedure.

Acute sensorineural hearing loss is an uncommon phenomenon in dentistry. We describe the case of a 79-year-old male who presented with acute sensorineural hearing loss occurring 2 days after a tooth extraction procedure under local anesthesia. Possible mechanisms are discussed. He was treated with vasodilators (Ginaton and Alprostadil Injection) and Mecobalamin injection with benefit. High dose oral steroids (1 mg/kg) and low molecular weight dextran were used.

Bioceramic akermanite enhanced vascularization and osteogenic differentiation of human induced pluripotent stem cells in 3D scaffolds in vitro and vivo.

A growing number of studies suggest that the modulation of cell differentiation by biomaterials is critical for tissue engineering. In previous work, we demonstrated that human induced pluripotent stem cells (iPSCs) are remarkably promising seed cells for bone tissue engineering. In addition, we found that the ionic products of akermanite (Aker) are potential inducers of osteogenic differentiation of iPSCs. Furthermore, composite scaffolds containing polymer and bioceramics have more interesting properties compared to pure bioceramic scaffolds for bone tissue engineering. The characteristic of model biomaterials in bone tissue engineering is their ability to control the osteogenic differentiation of stem cells and simultaneously induce the angiogenesis of endothelia cells. Thus, this study aimed at investigating the effects of poly(lactic-co-glycolic acid)/Aker (PLGA-Aker) composite scaffolds on angiogenic and osteogenic differentiation of human iPSCs in order to optimize the scaffold compositions. The results from Alizarin Red S staining, qRT-PCR analysis of osteogenic genes (BMP2, RUNX2, ALP, COL1 and OCN) and angiogenic genes (VEGF and CD31) demonstrated that PLGA/Aker composite scaffolds containing 10% Aker exhibited the highest stimulatory effects on the osteogenic and angiogenic differentiation of human iPSCs among all scaffolds. After the scaffolds were implanted in nu/nu mice subcutaneous pockets and calvarial defects, H&E staining, BSP immunostaining, qRT-PCR analysis and micro-CT analysis (BMD, BV/TV) indicated that PLGA + 10% Aker scaffolds enhanced the vascularization and osteogenic differentiation of human iPSCs and stimulated the repair of bone defects. Taken together, our work indicated that combining scaffolds containing silicate bioceramic Aker and human iPSCs is a promising approach for the enhancement of bone regeneration.

Defect-engineered TiO2 Hollow Spiny Nanocubes for Phenol Degradation under Visible Light Irradiation.

Herein, we mainly report a strategy for the facile synthesis of defect-engineered F-doped well-defined TiO2 hollow spiny nanocubes, constructed from NH4TiOF3 as precursor. The topological transformation of NH4TiOF3 mesocrystal is accompanied with fluorine anion releasing, which can be used as doping source to synthesize F-doped TiO2. Our result shows that the introduction of oxygen vacancies (Vo's) and F dopant can be further achieved by a moderate photoreduction process. The as prepared sample is beneficial to improve photocatalystic degradation and Photoelectrochemical (PEC) efficiency under visible light irradiation. And this improvement in photocatalytic and photoelectrocatalytic performance can be ascribed to the significant enhancement of visible light absorption and separation of excited charges resulted from the presence of oxygen vacancies, F- ions and hollow structure of TiO2.

Dual-stimuli-responsive TiO x /DOX nanodrug system for lung cancer synergistic therapy.

Biological applications of nanosheets are rapidly increasing currently, which introduces new possibilities to improve the efficacy of cancer chemotherapy and radiotherapy. Herein, we designed and synthesized a novel nano-drug system, doxorubicin (DOX) loaded titanium peroxide (TiO x ) nanosheets, toward the synergistic treatment of lung cancer. The precursor of TiO2 nanosheets with high specific surface area was synthesized by a modified hydrothermal process using the polymer P123 as a soft template to control the shape. TiO x nanosheets were obtained by oxidizing TiO2 nanosheets with H2O2. The anti-cancer drug DOX was effectively loaded on the surface of TiO x nanosheets. Generation of reactive oxygen species, including H2O2, ·OH and ·O2 -, was promoted from TiO x nanosheets under X-ray irradiation, which is effective for cancer radiotherapy and drug release in cancer cells. In this way, chemotherapy and radiotherapy were combined effectively for the synergistic therapy of cancers. Our results reinforce the DOX loaded TiO x nanosheets as a pH sensitive and X-ray controlled dual-stimuli-responsive drug release system. The cytotoxicity, cellular uptake, and intracellular location of the formulations were evaluated in the A549 human non-small cell lung cancer cell line. Our results showed that TiO x /DOX complexes exhibited a greater cytotoxicity toward A549 cells than free DOX. This work demonstrates that the therapeutic efficacy of DOX-loaded TiO x nanosheets is strongly dependent on their loading mode and the chemotherapeutic and radiotherapy effect is improved under X-ray illumination, which provides a significant breakthrough for future applications of TiO x as a light activated drug carrier in cancer chemotherapy and radiotherapy.

[MicroRNA-20a Promotes Osteogenic Differentiation of C3H/10T1/2 Cells through Regulating CKIP-1 Expression].

OBJECTIVE: To investigate the effect of microRNA-20a(MiR-20a) on osteogenic differentiation of mouse C3H/10T1/2 cells and its regulatory mechanism. METHODS: Osteogenic differentiation of C3H/10T1/2 cells were identified by ALP staining and qRT-PCR. MiR-20a mimics and CKIP-1 siRNA were transfected into C3H/10T1/2 cells respectively with lipo3000. The expression of osteoblast marker genes, miR-20a and CKIP-1 were quantitatively assessed by qRT-PCR. RESULTS: miR-20a expression was up-regulated during osteoblast differentiation of C3H/10T1/2 cells. Overexpression of miR-20a promoted osteogenic differentiation. Furthermore, miR-20a inhibited the expression of bone formation negative regulator CKIP-1. Additionally, CKIP-1 knockdown promoted osteogenic differentiation. CONCLUSION: MiR-20a promotes osteogenic differentiation of C3H/10T1/2 cells possibly through inhibiting the expression of CKIP-1.

The stimulation of osteogenic differentiation of embryoid bodies from human induced pluripotent stem cells by akermanite bioceramics.

Induced pluripotent stem cells (iPSCs) have great potential as seed cells for tissue engineering applications. Previous studies have shown that iPSCs could be induced to differentiate into bone forming cells. However, in a tissue engineering approach, seeding cells in biomaterials is required, and the effect of biomaterials on cell growth and differentiation is critical for the success of the formation of engineered tissues. In this study, we investigated the effect of akermanite, a bioactive ceramic, on the osteogenic differentiation of embryoid body (EB) cells derived from human iPSCs. The results showed that, in the presence of osteogenic factors (ascorbic acid, dexamethasone, and ß-glycerophosphate), ionic extracts of akermanite enhanced the osteogenic differentiation of EB cells as compared with normal osteogenic medium. Alkaline phosphatase (ALP) activity and the expression of osteogenic marker genes such as osteocalcin (OCN), collagen (COL-1), RUNX2, and BMP2 are significantly increased by the stimulation of akermanite ceramic extracts at certain concentration ranges. More interesting is that the medium containing extracts of akermanite but without osteogenic factors also showed stimulatory effects on the osteogenic differentiation of EB cells as compared to normal growth medium without osteogenic factors, such as ascorbic acid, dexamethasone, and ß-glycerophosphate, not at the early stage of culture, but only at the later stage of the culture period (21 days). These results suggest that akermanite as a bioactive material together with human iPSCs might be used for bone tissue engineering applications.

Aging performances for resisting low-temperature of three dental Yttria-stabilized zirconia ceramic core materials.

BACKGROUND: The low-temperature resistance aging performance of Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is the key effective factor that influences the long-term success rate of prosthesis. The objective of this study was to test and compare the aging performances for resisting low temperature of Lava Frame, Cercon Smart, and Upcera Yttria-stabilized zirconia core materials, via analyzing the micro and the crystal phases of the materials, and measure the three-point bending strength and the fracture toughness. METHODS: The three zirconia green bodies were prepared as 60 test samples for three-point bending strength and as 60 test samples for fracture toughness. The test samples for three-point bending strength and fracture toughness were assigned to five groups and were treated respectively for 0, 5, 10, 15, and 20 hours to observe the micro and the crystal phases of the test samples. Then the three-point bending strength and fracture toughness were tested by X-ray diffraction (XRD). RESULTS: The m phase content of Lava Frame was raised from 7.70% to 13.01%; the m phase content of Cercon Smart was raised from 4.95% to 8.53%; and Lava Frame is raised from 10.84% to 35.18%. The three-point bending strengths of the three zirconia core materials were higher than 1100 MPa and the fracture toughness was higher than 3 MPa·m(1/2). The three-point bending strength and the fracture toughness of Upcra zirconia decreased the most, followed by Lava Frame, and then by Cercon Smart. CONCLUSION: The aging resistance sequences of the three zirconia core materials are, from strong to weak, Cercon Smart, Lava Frame, and Upcera.

Posterolateral spinal fusion with nano-hydroxyapatite-collagen/PLA composite and autologous adipose-derived mesenchymal stem cells in a rabbit model.

Spinal fusion is routinely performed to treat low back pain caused by degeneration of intervertebral discs. An autologous bone graft derived from the iliac crest is the standard procedure used for spinal fusion. However, several shortcomings, including pseudarthrosis, pain and the need for blood transfusion are known to be associated with the procedure. Our study analysed the effectiveness of a new mineralized collagen matrix, nano-hydroxyapatite-collagen-polylactic acid (nHAC-PLA), combined with autologous adipose-derived mesenchymal stem cells (ADMSCs) as a graft material for posterolateral spinal fusion in a rabbit model. Forty rabbits were randomly divided into four groups: autologous iliac crest bone group (ACB), nHAC-PLA composite group (nHAC-PLA), autologous iliac crest bone mixed with nHAC-PLA composite group (ACB + nHAC-PLA), and nHAC-PLA composite combined with ADMSCs (ADMSCs + nHAC-PLA). The viability and the proliferation of the ADMSCs seeded on the scaffolds were evaluated by live/dead kit and MTT assay in vitro, respectively. Lumbar posterolateral fusions were assessed by manual palpation, radiographical and histological procedures, mechanical strength and scanning electronic microscopy (SEM) in 10 weeks of observation. The results showed that the rate of fusion was significantly higher in the ACB and ADMSCs + nHAC-PLA groups than that in the nHAC-PLA and ACB + nHAC-PLA groups. It was not significantly higher in the ACB group than in the ADMSCs + nHAC-PLA group. From microstructural analysis of the samples using histological staining methods, there was more new bone-like tissue formation in the ACB and ADMSCs + nHAC-PLA groups than that in the other two groups at the 10th postoperative week. Our study demonstrated the effective impact of nHAC-PLA combined with ADMSCs in rabbit posterolateral spinal fusion.

Biocompatibility and Osteogenic Capacity of Periodontal Ligament Stem Cells on nHAC/PLA and HA/TCP Scaffolds.

This study investigated the effects of a newly-developed scaffold, nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA), on the attachment, proliferation and osteogenic capability of dog periodontal ligament stem cells (PDLSCs) in vitro and in vivo. Hydroxyapatite/tricalcium phosphate (HA/TCP), a commonly used bone substitute, was used as a positive control. PDLSCs isolated from dog molar were incubated in an osteogenic medium to evaluate their osteogenic differentiation in vitro, and then seeded onto nHAC/PLA and HA/TCP scaffolds. In vitro cell attachment, proliferation and differentiation were assessed by scanning electron microscopy (SEM), cell counting, 3-[4,5-dimethythiazol-2-yl]-5-[3-carboxy-phenyl]-2-[4-sulfophenyl]-2H-tetrazolium and alkaline phosphate activity, and reverse transcription-polymerase chain reaction, respectively. Finally, the constructs were implanted subcutaneously into dogs to investigate their osteogenic capacity. After osteogenic induction for 21 days, PDLSCs differentiated into osteogenic lineage, as indicated by the expressions of osteoblastic differentiation genes CoL-I, OCN and OPN mRNA, and the formation of mineral deposits. When seeded onto scaffolds, the cells attached and spread well, and retained their osteogenic phenotypes on both scaffolds. Comparatively, cell number and proliferative viability on nHAC/PLA constructs were greater than those on HA/TCP constructs (P < 0.05). Histological results showed that new bone and osteoid was formed in both groups, and histomorphometric analysis demonstrated that the amount of newly formed bone in the nHAC/PLA group was higher than that in the HA/TCP group (P < 0.05). This study suggests that nHAC/PLA can be used as a potent scaffold for alveolar bone regeneration.

Telocytes accompanying cardiomyocyte in primary culture: two- and three-dimensional culture environment.

Recently, the presence of telocytes was demonstrated in human and mammalian tissues and organs (digestive and extra-digestive organs, genitourinary organs, heart, placenta, lungs, pleura, striated muscle). Noteworthy, telocytes seem to play a significant role in the normal function and regeneration of myocardium. By cultures of telocytes in two- and three-dimensional environment we aimed to study the typical morphological features as well as functionality of telocytes, which will provide important support to understand their in vivo roles. Neonatal rat cardiomyocytes were isolated and cultured as seeding cells in vitro in two-dimensional environment. Furthermore, engineered myocardium tissue was constructed from isolated cells in three-dimensional collagen/Matrigel scaffolds. The identification of telocytes was performed by using histological and immunohistochemical methods. The results showed that typical telocytes are distributed among cardiomyocytes, connecting them by long telopodes. Telocytes have a typical fusiform cell body with two or three long moniliform telopodes, as main characteristics. The vital methylene blue staining showed the existence of telocytes in primary culture. Immunohistochemistry demonstrated that some c-kit or CD34 immuno-positive cells in engineered heart tissue had the morphology of telocytes, with a typical fusiform cell body and long moniliform telopodes. Also, a significant number of vimentin+ telocytes were present within engineered heart tissue. We suggest that the model of three-dimensional engineered heart tissue could be useful for the ongoing research on the functional relationships of telocytes with cardiomyocytes. Because the heart has the necessary potential of changing the muscle and non-muscle cells during the lifetime, telocytes might play an active role in the heart regeneration process. Moreover, telocytes might be a useful tool for cardiac tissue engineering.

[Experiment on inducing human periodontal ligament stem cells into adipose cells].

OBJECTIVE: To explore the capability of human periodontal ligament stem cells (PDLSCs) differentiating into adipose cells in vitro and to determine their changes in cell morphology, structure and function during differentiation. METHODS: PDLSCs isolated by magnetic-activated cell selection were treated continuously with adipogenic medium for 21 d. Then the cell morphology, ultrastructure, adipose specific markers of low density lipoprotein (LPL) and peroxisome proliferator activated receptor-gamma (PPAR-gamma) were analyzed by inverted contrast microscope, trans mission electron microscope (TEM), flow cytometry, immunofluorescence, RT-PCR and Western blot, respectively. These adipose-like cells were also identified by oil red O staining to determine the formation of lipid droplet, and the non-induced cells were used as control. RESULTS: After continuous induction, the treated cells differentiated into adipose-like cells with round shape, and large amount of lipid drop in cytoplasm. 96.54% of the PDLSCs were found to differentiate into adipose cells as showed by flow cytometry, the specific markers of LPL mRNA and PPAR-gamma mRNA, and oil red O staining, respectively. Further, PPAR-gamma protein was detected in the induced cells in a time-dependent manner. CONCLUSION: Human PDLSCs have the potential of differentiating into adipose cells under appropriate condition, and the differentiated cells exhibited characteristics of adipose cells both from cell morphology and from their functions.

Gene-modified stem cells combined with rapid prototyping techniques: a novel strategy for periodontal regeneration.

Periodontal disease, a worldwide prevalent chronic disease in adults, is characterized by the destruction of the periodontal supporting tissue including the cementum, periodontal ligament and alveolar bone. The regeneration of damaged periodontal tissue is the main goal of periodontal treatment. Because conventional periodontal treatments remain insufficient to attain complete and reliable periodontal regeneration, periodontal tissue engineering has emerged as a prospective alternative method for improving the regenerative capacity of periodontal tissue. However, the potential of periodontal regeneration seems to be limited by the understanding of the cellular and molecular events in the formation of periodontal tissue and by the insufficient collaboration of multi-disciplinary research that periodontal tissue engineering involves. In this paper, we first reviewed the recent advancements in stem cells, signaling factors, and scaffolds that relate to periodontal regeneration. Then we speculate that specific genes would improve regenerative capacity of these stem cells, which could differentiate into cementoblasts, osteoblasts and fibroblasts. In addition, the 3D scaffolds that mimic the different structure and physiologic functions of natural fibro-osseous tissue could be fabricated by rapid prototyping (RP) techniques. It was therefore hypothesized that gene-modified stem cells combined with rapid prototyping techniques would be a new strategy to promote more effective and efficient periodontal regeneration.