A Preliminary Investigation into the Effect of Low-Energy Lasers on Dental Pulp Stem Cell Proliferation and the Associated Mechanism.

BACKGROUND: Dental pulp stem cells (DPSCs) have self-renewal and multidirectional differentiation potentials. As such, DPSCs have a wide range of clinical applications. Low-level laser therapy (LLLT) has positive photobiostimulatory effects on cell proliferation, angiogenesis, osteogenic differentiation, bone regeneration, and fracture healing. However, there have been few studies on the effect of low-energy lasers on DPSC proliferation. METHODS: DPSCs were obtained from dental pulp tissue. The effects of LLLT on the proliferation of DPSCs and the associated mechanisms were investigated by in vitro culture and laser irradiation. RESULTS: LLLT with energy densities of 3.5 J/cm2 and 14 J/cm2promoted the proliferation of DPSCs. Differential protein expression studies suggested the stimulation of DPSC proliferation by LLLT involved the PI3K-Akt and Rap1 signaling pathways, as well as the apoptosis-related pathway. CONCLUSION: This preliminary study demonstrated that low-energy lasers have a pro-proliferative effect on DPSCs, and identified possible associated mechanisms. Our findings provide a theoretical basis for the clinical application of DPSCs and suggest novel strategies for the treatment of related diseases.

A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.

BACKGROUND: gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy. METHODS: In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model. RESULTS: Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159. CONCLUSION: These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.

Potential Oral Health Benefits of Ginseng and Its Extracts.

This review discusses the effects of ginseng and its extracts in the treatment of dental caries, periodontal diseases, endodontic diseases, oral cancers, oral mucosal diseases, and some other dental associations. In the meantime, bioavailability and safety application of ginseng products are discussed. All of the articles reviewed were from PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang Data, and VIP Chinese Science and Technology Periodicals Full-Text Database through November 2022, including full-text English or non-English publications. Ginseng and its extracts were shown to have beneficial effects on oral diseases, and further studies are needed to understand the mechanisms and confirm the effects in humans.

Association of Allergic Symptoms in the First 2 Years of Life With Sleep Outcomes Among Chinese Toddlers.

Background: Previous studies have linked allergic symptoms to sleep in children, but the associations might be different when considering different types of allergic symptoms or sleep outcomes. Moreover, the combined effects of multiple allergic symptoms remain unclear in early life. This study aimed to investigate the associations between multiple allergic symptoms and sleep outcomes in early life. Methods: We included 673 toddlers aged 2 years from a birth cohort in Guangzhou, China. We identified allergic symptoms (skin, eyes and nose, gastrointestinal tract, mouth and lips, and wheeze) within 2 years via standard questionnaires. Sleep outcomes including sleep duration and quality over the past month were assessed based on the Chinese version of the Brief Infant Sleep Questionnaire. Associations between allergic symptoms and sleep outcomes were examined using multivariable linear regression and logistic regression. Results: Compared to children without allergic symptoms, children with allergic nasal and ocular symptoms had higher odds of frequent nighttime awakenings (OR = 1.41; 95% CI: 1.03, 1.93) and irregular sleep (OR = 1.45, 95% CI: 1.05, 2.00); children with allergic gastrointestinal symptoms slept 0.28 h less during nighttime (95% CI: -0.48, -0.07) and 0.25 h less per day (95% CI: -0.43, -0.08), and had 59% higher odds of irregular sleep (95% CI: 1.24, 2.04). We also found significant association of multiple allergic symptoms with shortened nighttime sleep duration and increased irregular sleep. Whereas, allergic skin, mouth and lips, and wheeze symptoms were not significantly associated with sleep outcomes. Conclusion: Allergic symptoms within 2 years of age were adversely associated with sleep outcomes, which highlight the importance of early screening of allergic symptoms in toddlers in order to improve their sleep outcomes.

Chondrocyte Co-cultures with the Stromal Vascular Fraction of Adipose Tissue in Polyhydroxybutyrate/Poly-(hydroxybutyrate-co-hydroxyhexanoate) Scaffolds: Evaluation of Cartilage Repair in Rabbit.

Chondral defects are challenging to repair because of the poor self-healing capacity of articular cartilage. The aim of this study was to compare and investigate the cartilage regeneration of stromal vascular fraction (SVF) cells and adipose-derived stem cells (ASCs) co-cultured with chondrocytes seeding on scaffolds composed of polyhydroxybutyrate (PHB)/poly-(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx). In this study, the cellular morphologies and proliferation capabilities on scaffolds were evaluated. Next, scaffolds with 1:1 co-culture of ASCs/SVF and chondrocytes were implanted into the full-thickness cartilage defects in rabbit knee for 10 weeks. Cells seeded on the scaffolds showed better adhesion, migration, and proliferation in vitro. Importantly, implantation with scaffolds with SVF and chondrocytes revealed more desirable in vivo healing outcomes. Our results illustrate a one-step surgical procedure for the regeneration of focal cartilage defects using a mixture of SVF from adipose tissue and uncultured chondrocytes.