Background: Delayed wound healing in diabetic patients is one of the most challenging complications in clinical medicine, as it poses a greater risk of gangrene, amputation and even death. Therefore, a novel method to promote diabetic wound healing is of considerable interest at present. Previous studies showed that injection of MSC-derived exosomes has beneficial effects on wound healing. In current studies, we aimed to isolate exosomes derived from gingival mesenchymal stem cells (GMSCs) and then loading them to the chitosan/silk hydrogel sponge to evaluate the effects of this novel non-invasive method on skin defects in diabetic rats. Methods: GMSCs were isolated from human gingival connective tissue and characterized by surface antigen analysis and in vitro multipotent differentiation. The cell supernatant was collected to isolate the exosomes. The exosomes were characterized by transmission electron microscopy, Western blot and size distribution analysis. The chitosan/silk-based hydrogel sponge was prepared using the freeze-drying method and then structural and physical properties were characterized. Then, the exosomes were added to the hydrogel and tested in a diabetic rat skin defect model. The effects were evaluated by wound area measurement, histological, immunohistochemical and immunofluorescence analysis. Results: We have successfully isolated GMSCs and exosomes with a mean diameter of 127 nm. The chitosan/silk hydrogel had the appropriate properties of swelling and moisture retention capacity. The in vivo studies showed that the incorporating of GMSC-derived exosomes to hydrogel could effectively promote healing of diabetic skin defects. The histological analysis revealed more neo-epithelium and collagen in the hydrogel-exosome group. In addition, the hydrogel-exosome group had the highest microvessel density and nerve density. Conclusions: The combination of GMSC-derived exosomes and hydrogel could effectively promote skin wound healing in diabetic rats by promoting the re-epithelialization, deposition and remodeling of collagen and by enhancing angiogenesis and neuronal ingrowth. These findings not only provide new information on the role of the GMSC-derived exosomes in wound healing but also provide a novel non-invasive application method of exosomes with practical value for skin repair.

Background and Objective: It is widely accepted that there is an association between chronic obstructive pulmonary disease (COPD) and periodontitis. However, whether the periodontal status of the COPD patients is worse than that of the non-COPD subjects is seldom assessed. The findings currently available are inconsistent, some even contradictory. Therefore, we performed this meta-analysis to compare the periodontal health status of COPD patients and non-COPD subjects. Methods: PubMed and Embase were searched for all of the eligible studies which comparing the periodontal status between COPD patients and non-COPD subjects. The results of periodontal parameters in each study were extracted and the mean differences and 95% confidence intervals (CIs) for each parameter were calculated to determine their overall effects. Results: In total, 14 studies involving 3348 COPD patients and 20612 non-COPD controls were included and 9 periodontal indexes were analyzed. The mean differences (95% CIs) between COPD and non-COPD subjects for probing depth, clinical attachment loss, level of alveolar bone loss, plaque index, oral hygiene index, bleeding index, bleeding on probing, gingival index, and remaining teeth were 0.261 (0.020–0.501), 0.480 (0.280–0.681), 0.127 (0.000–0.254), 0.226 (0.043–0.408), 0.802 (0.326–1.279), 0.241 (−0.106 to 0.588), 6.878 (5.489–8.266), 0.364 (0.036–0.692), and −3.726 (−5.120 to −2.331), respectively. Conclusion: In summary, this meta-analysis demonstrates that the COPD patients suffer from worse periodontal health status, indicated by deeper periodontal pockets, high level of clinical attachment loss, worse oral hygiene, more inflammation and bleeding in the gingival tissue, and lower number of remaining teeth. Nevertheless, considering the limitations in our meta-analysis, more high-quality, and well-designed studies focusing on the periodontal health of the COPD patients are required to validate our conclusion.

Inflammation is a common feature of both peripheral arterial disease (PAD) and periodontitis. Some studies have evaluated the association between PAD and periodontitis. However, there is still no specialized meta-analysis that has quantitatively assessed the strength of the association. Thus, we conducted this meta-analysis to critically assess the strength of the association between PAD and periodontitis. PubMed, Embase, and the Cochrane Library were searched for observational studies of the association between periodontitis and PAD in February 2018. Risk ratios (RRs) and their 95% confidence intervals (CIs) from included studies were pooled to evaluate the strength of the association between periodontitis and PAD. Weighted mean differences (WMDs) and their 95% CIs were pooled to compare the difference in periodontal-related parameters between PAD and non-PAD patients. Seven studies including a total of 4307 participants were included in the meta-analysis. The pooled analysis showed that there was a significant difference in the risk of periodontitis between PAD patients and non-PAD participants (RR = 1.70, 95% CI = 1.25–2.29, P = 0.01). There was also a significant difference in number of missing teeth between PAD patients and non-PAD participants (WMD = 3.75, 95% CI = 1.31–6.19, P = 0.003). No significant difference was found in clinical attachment loss between PAD patients and non-PAD participants (WMD = − 0.05, 95% CI = − 0.03–0.19, P = 0.686). In conclusion, the results of this meta-analysis revealed a significant relationship between periodontitis and PAD. Moreover, our study indicated that PAD patients had more missing teeth than control subjects did. Further high-quality and well-designed studies with specific inclusion and exclusion criteria are required to strengthen the conclusions of this study.

Oral anticoagulation therapy is widely used to reduce the risks of thromboembolism. However, the therapy increases the risk of hemorrhage during the surgical procedures. The aim of this meta-analysis was to evaluate the bleeding risk of patients continuing or discontinuing oral anticoagulant therapy while undergoing dental extractions. Six electronic databases, including PubMed, Embase, Cochrane library, Web of Science, China Biology Medicine disc (CBM), and China National Knowledge Infrastructure (CNKI), were searched in March, 2016. Relevant articles were screened by two independent reviewers under our inclusion criteria. Quality was evaluated using the Cochrane Collaboration risk of bias tool. Meta-analyses were conducted with fixed and random effects models as appropriate. Six studies (with a total of 591 patients) were included in our meta-analysis. Our results showed that there was no significant difference in the bleeding risk between patients continuing or discontinuing oral anticoagulant therapy while undergoing dental extractions (risk ratio, 1.31; 95 % CI, 0.79, 2.14; P > 0.05). There was also no significant difference in bleeding risk 1 day (risk ratio, 0.91; 95 % CI, 0.35, 2.37; P > 0.05) and 7 days (risk ratio, 1.47; 95 % CI, 0.83, 2.59; P > 0.05) after the dental extraction. Under current studies and evidence, it appears that patients continuing oral anticoagulant therapy do not have an increased risk of bleeding after dental extractions compared to patients who discontinue oral anticoagulant therapy.

The treatment of large-area infected wounds remains a significant challenge, as there is no effective wound dressing for infected wound healing applicable to clinical applications. In this study, chitosan–silk fibroin composite scaffolds containing silver nanoparticles (AgNP) that underwent asymmetric modification were fabricated for tissue engineering dressings. The scaffolds were prepared from a solution containing a chitosan–silk–fibroin emulsion with added AgNPs using a lyophilization approach and with an asymmetric coating on the surface of one side. Transmission electron microscopy images and laser particle size analysis showed the AgNP distribution, scanning electron microscopy images showed the surface morphology of the dressings, and inductively coupled plasma mass spectrometry showed the silver content. The asymmetric wettability of the dressings was measured using a contact angle meter. High porosity, good moisture retention capability and appropriate tensile strength were observed by measuring the physical and mechanical properties. Good antimicrobial properties towards various bacteria were observed via in vitro antibacterial effect analysis. Controlled AgNP release by the dressings and their resistance to the infiltration of microorganisms were also observed in our experiments. A highly biocompatible dressing was observed by the MTT assay experiment and subcutaneous sensitization test. Moreover, the effects of the dressings on infected wound healing were measured in mice infected wound models. Analysis of the wound healing rate, bacterial cultures of the exudate, blood samples and histological examination all provided satisfactory results. These results demonstrate that the dressings we prepared offer the potential for infected wound tissue repair and regeneration.

GMSCs-Exo promote proliferation, migration, and tube formation of HUVECs by regulating the Wnt/β-catenin signalling pathway in a high-glucose environment. GMSCs-Exo were loaded and delivered via PHE microspheres, novel porous microscaffolds with superb biocompatibility.