HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway.

BACKGROUND: Stabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known. RESULTS: In this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague-Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway. CONCLUSIONS: This study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.

Exosomes derived from reparative M2-like macrophages prevent bone loss in murine periodontitis models via IL-10 mRNA.

BACKGROUND: Periodontitis is characterized by progressive inflammation and alveolar bone loss resulting in tooth loss finally. Macrophages including pro-inflammatory M1-like macrophages and reparative M2-like macrophages play a vital role in inflammation and tissue homeostasis in periodontitis. Among them, reparative M2-like macrophages have been shown to promote tissue repair and prevent bone loss. However, the mechanism of reparative M2 macrophages-induced osteoprotective effect remains elusive. RESULTS: Exosomes from reparative M2-like macrophages (M2-Exos) were isolated and identified successfully. M2-Exos could promote bone marrow stromal cells (BMSCs) osteogenic differentiation while suppressing bone marrow derived macrophage (BMDM) osteoclast formation, and prohibit pathological alveolar bone resorption because of the intercellular communication via exosomes. High expression level of IL-10 mRNA was detected not only in reparative M2-like macrophages but also in M2-Exos. Meanwhile, IL-10 expression level in BMSCs or BMDM was also upregulated significantly after co-culturing with M2-Exos in a concentration-dependent manner. In vitro, recombinant IL-10 proteins had the ability to selectively promote osteogenic differentiation of BMSCs and hinder osteoclast differentiation of BMDM. Moreover, after treatment with M2-Exos and IL-10R antibody together, the capacity of promoting osteogenesis and suppressing osteoclastogenesis of M2-Exos was significantly reversed. In vivo experiments further showed that M2-Exos reduced alveolar bone resorption in mice with periodontitis via IL-10/IL-10R pathway. CONCLUSION: In conclusion, our results demonstrate that the reparative M2-like macrophages could promote osteogenesis while inhibiting osteoclastogenesis in vitro as well as protect alveolar bone against resorption in vivo significantly. M2-Exos could upregulate the IL-10 cytokines expression of BMSCs and BMDM via delivering exosomal IL-10 mRNA to cells directly, leading to activation of the cellular IL-10/IL-10R pathway to regulate cells differentiation and bone metabolism. These results might partly account for the mechanism of osteoprotective effect of reparative M2-like macrophages and provide a novel perspective and a potential therapeutic approach on improving alveolar resorption by M2-Exos.

Predictors of peri-implant bone remodeling outcomes after the osteotome sinus floor elevation: a retrospective study.

BACKGROUND: This study aimed to evaluate the radiographic outcomes of implants after osteotome sinus floor elevation (OSFE), and further identify the separate predictors for these radiographic outcomes. METHODS: In this retrospective cohort study, a total of 187 implants were inserted into 138 patients using the OSFE technique. Seventy-four patients in the grafted group, and 64 patients in the non-grafted group completed this study. The vertical bone gain (VBG) and marginal bone loss (MBL) at 3 years following surgery were assessed as outcome variables. Based on extensive literature results, variables considered potential predictors of outcome variables included sex, age, tooth position, implant length, implant diameter, with or without grafting materials, residual bone height, sinus width, bone density, and sinus membrane thickness. Subsequently, the binary logistic regression analysis was applied with VBG and MBL as dependent variables, respectively. The receiver operating characteristic curve (ROC) with its area under the curve (AUC) was performed to further determine the predictive value of these predictors. RESULTS: One hundred and six implants in grafted group and 81 implants in the non-grafted group were analyzed. The average VBG was 2.12 ± 1.94 mm for the grafted group and 0.44 ± 1.01 mm for the non-grafted group at 3 years (P < 0.05). The mean MBL was 1.54 ± 1.42 mm for the grafted group and 1.13 ± 1.69 mm for the non-grafted group at 3 years (P > 0.05). After the adjustment for confounders, logistic regression analysis demonstrated that implant length, grafting, residual bone height, and sinus membrane thickness were predictors of VBG. The odds ratio for VBG was 3.90, 4.04, 4.13 and 2.62, respectively. Furthermore, grafting exhibited the largest AUC at 0.80. While tooth position and implant length were predictors of MBL, the odds ratio for MBL was 3.27 and 7.85, respectively. Meanwhile, implant length exhibited the largest AUC at 0.72. CONCLUSIONS: OSFE with or without simultaneous grafting materials both showed predictable clinical outcomes. Additionally, the present study is the first quantitative and significant verification that VBG has a significant association with sinus membrane thickness, as well as residual bone height, implant length and grafting. Whereas tooth position and implant length are markedly associated with MBL.

Clinical and radiographic variables related to implants with simultaneous grafts among type 2 diabetic patients treated with different hypoglycemic medications: a retrospective study.

BACKGROUND: The influence of different hypoglycemic agents on peri-implant variables among type 2 diabetes mellitus patients is still unclear. Therefore, the aim of this study was to assess the radiographic marginal bone loss and clinical parameters around implants in patients using different hypoglycemic agents. METHODS: In this retrospective cohort study, the dental implant records of type 2 diabetes mellitus patients who met the inclusion criteria were collected. The patients using only single medication as follows: insulin, metformin, or glucagon-like peptide-1 (GLP-1) drugs, were grouped according to their medication. These patients received implant placement with the same initial status, and all the prosthesis restorations were cement-retained ceramic crowns. The peri-implant marginal bone levels were evaluated by periapical radiographs immediately after implant placement and at 1 and 2-year follow-up visits. The baseline characteristics were compared among groups. The peri-implant radiographic marginal bone loss and clinical parameters were preliminarily compared using the Kruskal-Wallis test, and then the covariates were controlled by covariance analysis. Bonferroni post hoc adjustment test was performed for the multiple comparisons. RESULTS: After a review of more than 7000 medical records, a total of 150 patients with 308 implants at 1-year follow-up were assessed. The peri-implant marginal bone loss in the GLP-1 drug group was significantly smaller than the insulin group and metformin group (P < 0.01). The radiographic bone loss in the metformin group was higher than the insulin group (P < 0.05). Some of these included patients were lost to follow-up. Only 74 patients with 129 implants completed the 2-year follow-up. The radiographic bone loss in the metformin group was still higher than the insulin group (P < 0.05) and GLP-1 group (P < 0.01). There was no significant difference in the BOP (+) and the mean PD among groups (P > 0.05). CONCLUSIONS: The radiographic variables were not exactly the same among the patients with different hypoglycemic agents at both the 1 and 2-year follow-ups. After ensuring consistency in baseline characteristics, the positive effect of GLP-1 drugs on peri-implant bone remodeling may be no less than insulin or metformin. More studies are needed to verify the direct effect of these drugs on peri-implant bone. Clinical trial registration number ChiCTR2000034211 (retrospectively registered).

Construction and validation of the CRISPR/dCas9-EZH2 system for targeted H3K27Me3 modification.

Cell phenotypes are closely related to the epigenome, which could be precisely regulated by the targeted manipulation of epigenetic marks. Here, we have successfully produced a targeted histone methylation system, which consists of nuclease-null dCas9 protein, the sgRNA fused with PP7 RNA aptamers and the Enhancer of Zeste Homolog 2 (EZH2) fused to PP7 coat protein (PCP). Guided by the dCas9/sgRNA-PP7, the PCP-EZH2 can specifically target gene loci to catalyze 3 methylation of histone H3 lysine 27, resulting in the inhibition of gene expression. This kind of gene inhibition system is supposed to be highly effective, specific and flexible. As a proof-of-concept study, sgRNA targeting C/ebpα promoter region was designed. In the cells co-infected with the dCas9, sgRNA/C/ebpα-PP7 and PCP-EZH2, the expression of C/ebpα gene was significantly reduced via induction of trimethylation to H3K27 on C/ebpα promoter, with the results epigenetically inherited in the daughter cells. In conclusion, our results successfully established a gene modification system consisting of dCas9/sgRNA-PP7 and PCP-EZH2, providing a robust tool for targeted manipulation of gene epigenetic modification and expression.

Influences of Schneiderian membrane conditions on the early outcomes of osteotome sinus floor elevation technique: a prospective cohort study in the healing period.

OBJECTIVES: To radiographically investigate early outcomes of osteotome sinus floor elevation in the healing phase utilizing cone beam computed tomography and evaluate influences of Schneiderian membrane conditions. MATERIAL AND METHODS: One hundred patients were consecutively recruited for osteotome sinus floor elevation (OSFE) surgery using deproteinized bone mineral. CBCT was taken prior to (T0), immediately post-operatively (T1), and after the healing period (T2). Linear and volumetric measurements of the elevated region from T0 to T1 were performed for evaluation on computed tomography (CT). RESULTS: Osteotome sinus floor elevation were performed in 100 patients. One implant of each patient was selected. Mean residual bone height (RH) was 7.21 ± 1.12 mm. Mean sinus floor elevation height (SE) was 4.81 ± 0.75 mm. The mean endo-sinus bone gain after the healing period was 3.25 ± 0.83 mm. Pre-opterative CBCT scans revealed that 72 patients had a normal sinus membrane in osteotome region, 13 patients presented with flat thickened mucosa and 15 patients with antral pseudocysts. There is no significant difference in sinus mucosa elevation height, bone graft volume and new bone formation in group of Thickening membrane and Antral pseudocysts compared with normal. CONCLUSIONS: The radiographical results show that OSFE is a safe and predictable surgical procedure in residual bone height of 7.21 ± 1.12 mm. Mild flat thickening (>2 and <5 mm) and antral pseudocysts in a small size without clinical symptoms may not be contraindications to OSFE surgery.

Longitudinal response of membrane thickness and ostium patency following sinus floor elevation: a prospective cohort study.

OBJECTIVES: To investigate the influence of sinus floor elevation (SFE) on sinus physiology, including Schneiderian membrane thickness (MT) and ostium patency, using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Based on pre-established selection criteria, 53 patients in combination with 53 sinuses were referred for SFE with a lateral approach using deproteinized bone mineral. CBCT was performed prior to, immediately after surgery and before staged implant placement. The Schneiderian MT of the elevated region, ostium patency, and other clinical data was evaluated. RESULTS: The two-stage sinus augmentation technique was applied in 33 males and 20 females. Four membrane perforations were observed during the surgical procedure. The Schneiderian membrane exhibited significant swelling immediately after augmentation (P < 0.0001), but this difference disappeared after a mean healing period of 7.51 months. The corresponding changes were also observed for ostium patency with a tendency of transient obstruction after surgery. Sinuses with flat mucosal thickening or pseudocysts did not present a liability of perforation compared to the normal cases, and the augmentation procedure was not likely to deteriorate the pathology of mucosal thickening or pseudocysts. CONCLUSIONS: The results show that SFE with a lateral approach has no significant influence on MT and ostium patency after the healing period except for postoperative transient swelling and obstruction. Thickened membranes and antral pseudocysts in a small size might not be contraindications to SFE from the standpoint of the surgical impact on the Schneiderian membrane.

Preparation and Evaluation of Two Apatites with Spherical Nanocrystal Morphology.

Spherical nanocrystal of apatite has been proved to be beneficial for osteoblast growth. Two apatites with spherical nanocrystal morphology were prepared in this study by chemical wet method and further sintering process. SEM exhibited that both apatites had spherical nanocrystal morphology. The crystal morphology and size was approaching to each other. XRD showed the apatites separately were hydroxyapatite and tricalcium phosphate phases. The cellular biocompatibility was evaluated by osteoblasts for these two spherical nanocrstal apatites. The MTT result indicated a higher cell proliferation rate for spherical tricalcium phosphate group. The ALP activity assay also strongly favored the tricalcium phosphate group. RT-PCR results indicated that Collagen I had a higher transcription level on the spherical tricalcium phosphate group. SEM results showed robust cell growth on the materials. It was concluded that the spherical nanophase tricalcium phosphate was superior to the cellular biocompatibility of spherical nanophase hydroxyapatite and the results were helpful in the manufacture of more suitable tissue engineering scaffolds.

Ridge expansion alone or in combination with guided bone regeneration to facilitate implant placement in narrow alveolar ridges: a retrospective study.

OBJECTIVE: To evaluate the long-term outcomes of ridge expansion technique in dealing with horizontal bony insufficiency of alveolar ridges for implant placement. MATERIALS AND METHODS: During the period 2004-2009, 168 patients with width insufficiency of alveolar ridges were treated using the ridge expansion technique to obtain an improved bony base for implant placement. Depending on the severity of width insufficiency, the surgical procedures were classified into two groups: ridge expansion alone (Group 1) and ridge expansion in combination with guided bone regeneration (Group 2). After 4-6 months of unloaded healing, the implants were restored. The patients were followed up until 2013 with clinical and radiographic examinations. RESULTS: Among the 168 patients, 11 patients underwent a fracture of labial/buccal bony plate during surgery, which was corrected by changing the procedure into bone grafting, yielding a surgical failure rate of 6.5%. In the remaining 157 patients successfully treated by ridge expansion alone or in combination with GBR, 226 implants were simultaneously placed as planned. No implant failed over 2.8 years (6 months to 8 years) of follow-up, yielding a cumulative implant survival rate of 100% in each group. Six implants in Group 1 and 4 implants in Group 2, although osseointegrated and in function, did not fulfill success criteria: Cumulative implants' success rates were 93.2% in Group 1 and 95.6% in Group 2. The mean marginal bone losses during the first year in Group 1 and Group 2 were 0.69 and 0.43 mm, respectively, followed by an annual loss of ~ 0.06 and 0.07 mm, respectively, in the following years. No clinical parameter was abnormal. Twenty-two (10.4%) implants were exposed to peri-implant mucositis, whereas 19 (11.0%) implant-supported restorations were involved in prosthetic complications. CONCLUSIONS: The preliminary results of this retrospective study indicate that ridge expansion alone or in combination with GBR can be considered an effective and safe procedure for treatment of width insufficiency of alveolar ridges on the purpose of implant application.

Integrating network pharmacology and Mendelian randomization to explore potential targets of matrine against ovarian cancer.

BACKGROUND: Matrine has been reported inhibitory effects on ovarian cancer (OC) cell progression, development, and apoptosis. However, the molecular targets of matrine against OC and the underlying mechanisms of action remain elusive. OBJECTIVE: This study endeavors to unveil the potential targets of matrine against OC and to explore the intricate relationships between these targets and the pathogenesis of OC. METHODS: The effects of matrine on the OC cells (A2780 and AKOV3) viability, apoptosis, migration, and invasion was investigated through CCK-8, flow cytometry, wound healing, and Transwell analyses, respectively. Next, Matrine-related targets, OC-related genes, and ribonucleic acid (RNA) sequence data were harnessed from publicly available databases. Differentially expressed analyses, protein-protein interaction (PPI) network, and Venn diagram were involved to unravel the core targets of matrine against OC. Leveraging the GEPIA database, we further validated the expression levels of these core targets between OC cases and controls. Mendelian randomization (MR) study was implemented to delve into potential causal associations between core targets and OC. The AutoDock software was used for molecular docking, and its results were further validated using RT-qPCR in OC cell lines. RESULTS: Matrine reduced the cell viability, migration, invasion and increased the cell apoptosis of A2780 and AKOV3 cells (P< 0.01). A PPI network with 578 interactions among 105 candidate targets was developed. Finally, six core targets (TP53, CCND1, STAT3, LI1B, VEGFA, and CCL2) were derived, among which five core targets (TP53, CCND1, LI1B, VEGFA, and CCL2) differential expressed in OC and control samples were further picked for MR analysis. The results revealed that CCND1 and TP53 were risk factors for OC. Molecular docking analysis demonstrated that matrine had good potential to bind to TP53, CCND1, and IL1B. Moreover, matrine reduced the expression of CCND1 and IL1B while elevating P53 expression in OC cell lines. CONCLUSIONS: We identified six matrine-related targets against OC, offering novel insights into the molecular mechanisms underlying the therapeutic effects of matrine against OC. These findings provide valuable guidance for developing more efficient and targeted therapeutic approaches for treating OC.

Role of LRP5/6/GSK-3ß/ß-catenin in the differences in exenatide- and insulin-promoted T2D osteogenesis and osteomodulation.

BACKGROUND AND PURPOSE: Insulin and exenatide are two hypoglycaemic agents that exhibit different osteogenic effects. This study compared the differences between exenatide and insulin in osseointegration in a rat model of Type 2 diabetes (T2D) and explored the mechanisms promoting osteogenesis in this model of T2D. EXPERIMENTAL APPROACH: In vivo, micro-CT was used to detect differences in the peri-implant bone microstructure in vivo. Histology, dual-fluorescent labelling, immunofluorescence and immunohistochemistry were used to detect differences in tissue, cell and protein expression around the implants. In vitro, RT-PCR and western blotting were used to measure the expression of osteogenesis- and Wnt signalling-related genes and proteins in bone marrow mesenchymal stromal cells (BMSCs) from rats with T2D (TBMSCs) after PBS, insulin and exenatide treatment. RT-PCR was used to detect the expression of Wnt bypass cascade reactions under Wnt inactivation. KEY RESULTS: Micro-CT and section staining showed exenatide extensively promoted peri-implant osseointegration. Both in vivo and in vitro experiments showed exenatide substantially increased the expression of osteogenesis-related and activated the LRP5/6/GSK-3ß/ß-catenin-related Wnt pathway. Furthermore, exenatide suppressed expression of Bmpr1a to inhibit lipogenesis and promoted expression of Btrc to suppress inflammation. CONCLUSION AND IMPLICATIONS: Compared to insulin, exenatide significantly improved osteogenesis in T2D rats and TBMSCs. In addition to its dependence on LRP5/6/GSK-3ß/ß-catenin signalling for osteogenic differentiation, exenatide-mediated osteomodulation also involves inhibition of inflammation and adipogenesis by BMPR1A and ß-TrCP, respectively.

Inhibition of PTEN promotes osteointegration of titanium implants in type 2 diabetes by enhancing anti-inflammation and osteogenic capacity of adipose-derived stem cells.

Background: The low osteogenic differentiation potential and attenuated anti-inflammatory effect of adipose-derived stem cells (ADSCs) from animals with type 2 diabetes mellitus (T2DM) limits osseointegration of the implant. However, the underlying mechanisms are not fully understood. Methods: Western blotting and qRT-PCR analyses were performed to investigate the effects of PTEN on the osteogenic capacity of ADSCs of T2DM rats (TADSCs). We conducted animal experiments in T2DM-Sprague Dawley (SD) rats to evaluate the osteogenic capacity of modified TADSC sheets in vivo. New bone formation was assessed by micro-CT and histological analyses. Results: In this study, adipose-derived stem cells of T2DM rats exhibited an impaired osteogenic capacity. RNA-seq analysis showed that PTEN mRNA expression was upregulated in TADSCs, which attenuated the osteogenic capacity of TADSCs by inhibiting the AKT/mTOR/HIF-1α signaling pathway. miR-140-3p, which inhibits PTEN, was suppressed in TADSCs. Overexpression or inhibition of PTEN could correspondingly reduce or enhance the osteogenic ability of TADSCs by regulating the AKT/mTOR/HIF-1α signaling pathway. TADSCs transfected with PTEN siRNA resulted in higher and lower expressions of genes encoded in M2 macrophages (Arg1) and M1 macrophages (iNOS), respectively. In the T2DM rat model, PTEN inhibition in TADSC sheets promoted macrophage polarization toward the M2 phenotype, attenuated inflammation, and enhanced osseointegration around implants. Conclusion: Upregulation of PTEN, which was partially due to the inhibition of miR-140-3p, is important for the attenuated osteogenesis by TADSCs owing to the inhibition of the AKT/mTOR/HIF-1α signaling pathway. Inhibition of PTEN significantly improves the anti-inflammatory effect and osteogenic capacity of TADSCs, thus promoting peri-implant bone formation in T2DM rats. Our findings offer a potential therapeutic approach for modifying stem cells derived from patients with T2DM to enhance osseointegration.

Synchronous stabilization of Pb, Zn, Cd, and As in lead smelting slag by industrial solid waste.

In order to prevent heavy metal (HM) pollution from lead smelting slag (LSS) to the surrounding environment, this work investigated the feasibility, influencing factors, and mechanisms of using industrial solid waste such as fly ash (FA), oil sludge pyrolysis residue (PR), and steel slag (SS) as remediation amendments. The results demonstrated that the stabilization process was influenced by the material dosage, water content, and LSS particle size. Compared to single materials, the combination amendment PR2FA1 (with a mass ratio of PR to FA as 2:1) exhibited the best stabilization effect, simultaneously reducing the leaching concentrations of As, Zn, Cd, and Pb in LSS to 0.032, 0.034, 0.002, and 0.014 mg/L, respectively. The pH value of the leachate remained between 8 and 9, which met the requirements of surface water quality class IV (GB3838-2002). Through morphological analysis, microscopic characterization, and simulated solution adsorption experiments, it was determined that the stabilization process of HMs was controlled by various mechanisms, including electrostatic attraction, physical adsorption, ion exchange, and chemical precipitation. PR2FA1 had more active components, and its fine-porous structure provided more active sites, resulting in good stabilization performance for As, Zn, Cd, and Pb. Furthermore, cost analysis showed that PR2FA1, as an environmentally friendly material, could generate profits of 157.2 ¥/ton. In conclusion, the prepared PR2FA1 not only addressed the HMs pollution from lead smelting slag to the surrounding environment but also achieved the safe and resourceful disposal of hazardous waste-oil sludge. Its excellent performance in stabilizing HMs and cost-effectiveness suggested promising commercial applications.

TRAF6 promotes osteogenesis in ADSCs through Raf-Erk-Merk-Hif1-a pathway.

Critical-size defects (CSDs) are challenging oral clinical issues that need to be solved. Adipose-derived mesenchymal stem cells (ADSCs) and gene therapy offer a new target to solve these issues. Consequently, ADSCs attract more and more attention because of advantages such as easy obtainability and no ethical concerns. TNF receptor-associated factor 6 (TRAF6) is a significant binding protein both of tumour necrosis factor superfamily and of the toll/interleukin-1 receptor superfamily. Evidence is accumulating that TRAF6 inhibited osteoclast formation and promoted the proliferation of multiple myeloma cell lines and bone resorption. Here, we reported that overexpression of TRAF6 enhanced the proliferation, migration and osteogenesis of ADSCs through Raf-Erk-Merk-Hif1a pathway. Cell sheet of ADSCs combined with TRAF6 accelerated the healing of CSDs. In a word, TRAF6 enhanced osteogenesis, migration and proliferation through Raf-Erk-Merk-Hif1a pathway.

Construction and performance of exendin-4-loaded chitosan-PLGA microspheres for enhancing implant osseointegration in type 2 diabetic rats.

The updating and optimization of drug delivery systems is critical for better in vivo behaviors of drugs, as well as for improving impaired implant osseointegration in diabetes. Numerous studies have reported the benefits of exendin-4 on diabetic bone, with the potential to enhance osseointegration in diabetes. To construct an appropriate sustained-release system of exendin-4 targeting implant osseointegration in diabetes, this study fabricated exendin-4-loaded microspheres using poly(lactic-co-glycolic acid) (PLGA) and chitosan. The morphology, size, encapsulation efficiency, and drug release behavior of microspheres were investigated. The bioactivity of drug-loaded microspheres on cell proliferation and osteogenic differentiation of diabetic BMSCs was investigated to examine the pharmacologic action of exendin-4 loaded into chitosan-PLGA microspheres. Further, the influence of microspheres on osseointegration was evaluated using type 2 diabetes mellitus (T2DM) rat implant model. After 4 weeks, the samples were evaluated by radiological and histological analysis. The results of in vitro experiments showed that the prepared exendin-4-loaded chitosan-PLGA microspheres have good properties as a drug delivery system, and the chitosan could improve the encapsulation efficiency and drug release of PLGA microspheres. In addition, exendin-4-loaded microspheres could enhance the proliferation and osteogenic differentiation of diabetic BMSCs. The results of in vivo experiments showed the exendin-4-loaded microspheres significantly improved the impaired osseointegration and bone formation around implants in T2DM rats without affecting blood glucose levels. Thus, the local application of exendin-4-loaded chitosan-PLGA microspheres might be a promising therapeutic strategy for improving the efficacy of dental implants in T2DM individuals.

The Proangiogenic Potential of Rat Adipose-Derived Stromal Cells with and without Cell-Sheet Induction: A Comparative Study.

A functional vasculature for survival remains a challenge for tissue regeneration, which is indispensable for oxygen and nutrient supply. Utilizing mesenchymal stromal cells (MSCs) to alleviate tissue ischemia and repair dysfunctional or damaged endothelium is a promising strategy. Compared to other populations of MSCs, adipose-derived stromal cells (ASCs) possess a more significant proangiogenic potential and are abundantly available. Cell sheet technology has recently been widely utilized in bone engineering. Compared to conventional methods of seeding seed cell suspension onto biological scaffolds, cell sheet technology prevents cell loss and preserves the extracellular matrix (ECM). Nevertheless, the proangiogenic potential of ASC sheets remains unknown. In this study, rat ASC sheets were constructed, and their macro- and microstructures were examined. In addition, we investigated the effects of ASCs and ASC sheets on the biological properties and angiogenic capacity of endothelial cells (ECs). The results demonstrated that the ASC sheets gradually thickened as the number of cells and ECM increased over time and that the cells were in an active state of secretion. Similar to ASC-CM, the conditioned medium (CM) of ASC sheets could significantly enhance the proliferative capacity of ECs. ASC sheet-CM has significant advantages over ASC-CM in promoting the migration and angiogenesis of ECs, where the exosomes secreted by ASC sheets play an essential role. Therefore, using ASC sheets for therapeutic tissue and organ regeneration angiogenesis may be a valuable strategy.

Review of ectodermal dysplasia: case report on treatment planning and surgical management of oligodontia with implant restorations.

Dental implants have proven to be a reliable modality for the rehabilitation of missing teeth. However, there are limited reports on managing anodontia related to ectodermal dysplasia in the scientific literature. The severely reduced bone quantity due to the congenital absence of multiple natural teeth is the biggest challenge for the surgeon. There are a variety of bone augmentation procedures to establish adequate bone quantity, and the surgical planning should be used on an individual case basis. This is a report of a 19-year-old male patient affected by hypohidrotic ectodermal dysplasia. Oligodontia associated with severe atrophy of jaws was the chief complaint for seeking treatment. Based on clinical and radiographic examinations, 2 bone augmentation procedures were used to obtain sufficient width of alveolus for implant placement by performing an onlay bone graft in the maxilla and vertical distraction osteogenesis in the mandible. The treatment planning was discussed and informed consent was obtained.

[Effect of sustained release of recombinant rat insulin-like growth factor-1 from poly (lactide-CO-glycolide ) microspheres on bone formation in the peri-implant areas in Goto-Kakizaki rats with type 2 diabetes].

OBJECTIVE: To evaluate the effect of sustained release of recombinant rat insulin-like growth factor-1(rrIGF-1) from poly (lactide-CO-glycolide) (PLGA) microspheres on bone formation in the peri-implant areas in Goto-Kakizaki rats with type 2 diabetes. METHODS: Type 2 diabetes models were successfully established in 20 male Goto-Kakizaki rats, which were then randomly divided into treatment group (sustained release of rrIGF-1 from PLGA microspheres were loaded on the peri-implant areas, n=10) and diabetic group (loaded with isodose placebo from PLGA microspheres, n=10). Another ten male SD rats served as control group (did not sustain any loading). Titanium implants were inserted into the tibias of 30 diabetic and normal animals. Four, 5, and 8 weeks after implantation, local blood samples around the implants were obtained for the determination of serum osteocalcin (OCN), serum bone specific alkaline phosphatase (B-ALP), and serum procollagen I carboxyterminal propeptide (PICP) with enzyme linked immunosorbent assays. RESULTS: Four weeks after implantation, OCN, B-ALP, and PICP were significantly lower in both treatment group and diabetic group than in control group(both P<0.05). Five weeks after implantation, serum OCN and B-ALP levels of the diabetic group were significantly lower than those of the other two groups (all P<0.05). Serum PICP levels of both diabetic group and treatment group were significantly lower than that of control group(both P<0.05). The OCN level in the trealment group was significantly higher in the post-operative 5th week than in the post-operative 4th week, while the PICP levels in the diabetic group were significantly lower than those in the treatment group and control group in the post-operative 8th week (both P<0.05). CONCLUSION: Sustained release of rrIGF-1 from PLGA microspheres loaded on the local peri-implant areas can promote bone formation in the peri-implant areas in Goto-Kakizaki rats with type 2 diabetes.

[Insights into peri-implantitis and its prevention].

Peri-implantitis is one of the most common complications in dental implant treatment. Peri-implantitis is a crucial implication of implant failure, which is characterized by high morbidity and intractability. Thus, how to understand peri-implantitis correctly and deeply, and how to prevent its occurrence, are important problems that every dental implant surgeon has to face.

A preliminary study on submariners with xerostomia after a 3-month deployment.

To observe the clinical manifestations and salivary secretion of xerostomia patients in submariners who engaged in a three-month deployment. The general conditions and clinical examination of the 136 submariners were evaluated, by which the patients with xerostomia were screened out and their clinical manifestations were recorded. Besides, the flow rate of unstimulated saliva and stimulated saliva was measured and calculated. Subsequently, the related factors of xerostomia were quantitatively classified and statistically analyzed. In all the involved submariners, 42 were diagnosed to have xerostomia by physical examination after they returned from the task, among which 71.4% showed a decrease in unstimulated salivary flow rate and it was significantly correlated with the accompanying symptoms and their general conditions. Therefore, it was concluded that the occurrence of xerostomia could be related to the service life and job responsibilities of the submariners. The main manifestations were the reduction of unstimulated salivary secretion and the accompanying clinical symptoms such as cheilosis and angular cheilitis. Noticeably, the high psychological pressure and harsh living conditions need to be concerned, and further study should place more concentrations on these comprehensive influence factors and preventive actions of xerostomia.