Near-Infrared Ratiometric Hemicyanine-Based pH Fluorescence Probe with Bone Targetability for Monitoring Bone Resorption.

Accurate detection of bone resorption is extremely important in the orthodontic treatment process as it can provide a basis for clinical treatment strategies. Recently, pH-responsive fluorescence probes have received tremendous attention in bone resorption monitoring owing to their high sensitivity, good specificity, and in situ and real-time detection capabilities, but there are still some shortcomings like the increase in the risk of osteonecrosis of the jaw by use of bisphosphonate as the bone-targeting moiety and the insufficient monitoring accuracy due to susceptibility to interference. Herein, we designed and synthesized a near-infrared ratiometric hemicyanine-based pH fluorescence probe (Hcy-Asp6) with fluorescence-imaging and pH-determining capabilities, and bone targetability for more reliably and safely monitoring the bone resorption in orthodontic treatment. In vitro optical performance tests of Hcy-Asp6 revealed that the probe had high sensitivity, excellent photostability, reversibility, and strong resistance to interference, and the probe suggested excellent bone-binding ability and biocompatibility in the bone-targeting evaluation and the cytotoxicity test. Furthermore, in vitro and in vivo bone resorption monitoring assays demonstrated that this probe can detect bone resorption by fluorescence imaging and quantitative monitoring of pH associated with the bone resorption. Thus, the results indicated that this probe possessing bone targetability and accurate bone resorption-monitoring capability has an extraordinarily great clinical potential to be employed for real-time monitoring of bone resorption in orthodontic treatment and could also serve as a reference in bone resorption monitoring for other bone resorption-related diseases.

Near-Infrared Light-Controlled MicroRNA-21-Loaded Upconversion Nanoparticles to Promote Bone Formation in the Midpalatal Suture.

Rapid maxillary expansion (RME) is a common therapy for maxillary transverse deficiency. However, relapses after RME usually occur because of insufficient bone formation. MicroRNA-21 (miR-21) was reported as an important post-transcriptional modulator for osteogenesis. Herein, a photocontrolled miR-21 (PC-miR-21)-loaded nanosystem using upconversion nanoparticles (UCNPs) modified with poly(ether imide) (PEI), i.e., UCNPs@PEI@PC-miR-21, was constructed to promote bone formation in the midpalatal suture. UCNPs@PEI was constructed as the light transducer and delivery carrier. The UCNPs@PEI@PC-miR-21 nanocomplexes have good aqueous dispersibility and biocompatibility. The in vitro cell experiment suggested that UCNPs@PEI could protect PC-miR-21 from biodegradation and release PC-miR-21 into the cytoplasm under near-infrared light (NIR) irradiation. Furthermore, UCNPs@PEI@PC-miR-21 upregulated the expression of the osteogenic key markers, ALP, RUNX2, and COL1A1, at the levels of both genes and proteins. Besides, the results of the in vivo RME mice models further corroborated that photocontrollable UCNPs@PEI@PC-miR-21 accelerated bone formation with upregulating osteogenic markers of ALP, RUNX2, and osteoprotegerin and inducing fewer osteoclasts formation. In conclusion, UCNPs@PEI@PC-miR-21 nanoparticles with a NIR light could facilitate the remote and precise delivery of exogenous miR-21 to the midpalatal suture to promote bone formation during RME. This work represents a cutting-edge approach of gene therapy to promote osteogenesis in the midpalatal suture during RME and provides a frontier scientific basis for later clinical treatment.

Minimally invasive bone augmentation through subperiosteal injectable hydroxylapatite/laponite/alginate nanocomposite hydrogels.

Bone augmentation has an enormous demand in oral clinical treatment. Although there are various options available for clinical management to address it, these approaches could increase patient suffering due to surgical trauma and even cause psychological trauma to the patients. Moreover, presently, there is still a lack of well-considered microinvasive bone augmentation systems to deal with this challenge. Herein, we newly developed a subperiosteal injectable and osteogenesis-promoting hydroxylapatite/laponite/alginate nanocomposite hydrogels to address the insufficient microinvasive bone augmentation strategies. The physical performances (like swelling profiles, degradation behaviors, mechanical properties, and surface morphologies) of the gels were determined, and can be slightly tuned through altering concentrations of laponite. The cytocompatibility test results show outstanding biocompatibility of the hydrogels. Furthermore, the in vitro testing for bone-inducing activity and in vivo determination of bone-augmentation in the rat cranial subperiosteum exhibit that the hydrogels significantly promoted rat periosteum-derived mesenchymal stromal cells (P-MSCs) osteogenic differentiation in vitro and bone augmentation in vivo. Therefore, the research reveals that the nanocomposite hydrogels possessing subperiosteal microinvasive injectability, osteogenesis-enhancing capability, and clinical applicability have extremely great potential application in subperiosteal microinvasive bone augmentation.

Oral Vaccination with Engineered Probiotic Limosilactobacillus reuteri Has Protective Effects against Localized and Systemic Staphylococcus aureus Infection.

Staphylococcus aureus is a Gram-positive bacterium responsible for most hospital-acquired (nosocomial) and community-acquired infections worldwide. The only therapeutic strategy against S. aureus-induced infections, to date, is antibiotic treatment. A protective vaccine is urgently needed in view of the emergence of antibiotic-resistant strains associated with high-mortality cases; however, no such vaccine is currently available. In our previous work, the feasibility of implementing a Lactobacillus delivery system for development of S. aureus oral vaccine was first discussed. Here, we describe systematic screening and evaluation of protective effects of engineered Lactobacillus against S. aureus infection in terms of different delivery vehicle strains and S. aureus antigens and in localized and systemic infection models. Limosilactobacillus reuteri WXD171 was selected as the delivery vehicle strain based on its tolerance of the gastrointestinal environment, adhesion ability, and antimicrobial activities in vitro and in vivo. We designed, constructed, and evaluated engineered L. reuteri strains expressing various S. aureus antigens. Among these, engineered L. reuteri WXD171-IsdB displayed effective protection against S. aureus-induced localized infection (pneumonia and skin infection) and, furthermore, a substantial survival benefit in systemic infection (sepsis). WXD171-IsdB induced mucosal responses in gut-associated lymphoid tissues, as evidenced by increased production of secretory IgA and interleukin 17A (IL-17A) and proliferation of lymphocytes derived from Peyer's patches. The probiotic L. reuteri-based oral vaccine appears to have strong potential as a prophylactic agent against S. aureus infections. Our findings regarding utilization of Lactobacillus delivery system in S. aureus vaccine development support the usefulness of this live vaccination strategy and its potential application in next-generation vaccine development. IMPORTANCE We systematically screened and evaluated protective effects of engineered Lactobacillus against S. aureus infection in terms of differing delivery vehicle strains and S. aureus antigens and in localized and systemic infection models. Engineered L. reuteri was developed and showed strong protective effects against both types of S. aureus-induced infection. Our findings regarding the utilization of a Lactobacillus delivery system in S. aureus vaccine development support the usefulness of this live vaccination strategy and its potential application in next-generation vaccine development.

Mammary γδ T cells promote IL-17A-mediated immunity against Staphylococcus aureus-induced mastitis in a microbiota-dependent manner.

Mastitis, a common disease for female during lactation period that could cause a health risk for human or huge economic losses for animals, is mainly caused by S. aureus invasion. Here, we found that neutrophil recruitment via IL-17A-mediated signaling was required for host defense against S. aureus-induced mastitis in a mouse model. The rapid accumulation and activation of Vγ4+ γδ T cells in the early stage of infection triggered the IL-17A-mediated immune response. Interestingly, the accumulation and influence of γδT17 cells in host defense against S. aureus-induced mastitis in a commensal microbiota-dependent manner. Overall, this study, focusing on γδT17 cells, clarified innate immune response mechanisms against S. aureus-induced mastitis, and provided a specific response to target for future immunotherapies. Meanwhile, a link between commensal microbiota community and host defense to S. aureus mammary gland infection may unveil potential therapeutic strategies to combat these intractable infections.

Periodontal Parameters in Fixed Labial and Lingual Orthodontic Treatment: A Systematic Review and Meta-Analysis.

PURPOSE: To critically evaluate the periodontal parameters of patients receiving fixed labial and lingual orthodontic therapy. MATERIALS AND METHODS: The current systematic review was registered at PROSPERO. Clinical studies comparing the periodontal parameters between fixed labial and lingual orthodontic treatment were searched up to June 2022 in four electronic databases, and unpublished literature was searched at ClinicalTrial.gov. The risk of bias of randomised controlled clinical trials (RCTs) and non-randomised clinical trials (n-RCTs) was assessed using the Cochrane risk-of-bias tool 2.0 and the Risk of Bias in Non-randomised Studies of Interventions (ROBINS-I) assessment tool, respectively. The pooled periodontal parameters were calculated in random-effect meta-analyses. The confidence of evidence was assessed via the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Eight studies involving 223 patients were included in the current study. The risk of bias was high for 2 RCTs and 3 n-RCTs, and moderate for 3 n-RCTs. Patients receiving fixed lingual orthodontic treatment showed a lower plaque index (MD = -0.14; 95%CI -0.27 to -0.02). No statistically significant difference was found in the bleeding on probing index (MD = 0.11; 95%CI -0.03 to 0.25), gingival index (MD = 0.02; 95%CI -0.06 to 0.11), and periodontal pocket depth ( MD = 0.06; 95%CI -0.16 to 0.27) between the two groups. The overall quality of the evidence was very low to low. CONCLUSION: The present study indicates no obvious difference in periodontal parameters between the fixed labial and lingual orthodontic systems, although the overall quality was very low to low. Further RCTs with standardised outcome measures are needed.

Novel exopolysaccharide derived from probiotic Lactobacillus pantheris TCP102 strain with immune-enhancing and anticancer activities.

Probiotics are gaining attention due to their functions of regulating the intestinal barrier and promoting human health. The production of exopolysaccharide (EPS) is one of the important factors for probiotics to exert beneficial properties. This study aimed to screen exopolysaccharides-producing lactic acid bacteria (LAB) and evaluate the probiotic potential. we obtained three exopolysaccharide fractions (EPS1, EPS2, and EPS3) from Lactobacillus pantheris TCP102 and purified by a combination of ion-exchange chromatography and gel permeation chromatography. The structures of the fractions were characterized by FT-IR, UV, HPLC, and scanning electron microscopy (SEM) analysis. The Mw of EPS1, EPS2, and EPS3 were approximately 20.3, 23.0, and 19.3 kDa, and were mainly composed of galactose, glucose, and mannose, with approximate molar ratios of 2.86:1:1.48, 1.26:1:1, 1.58:1.80:1, respectively. Furthermore, SEM analysis demonstrated that the three polysaccharide fractions differ in microstructure and surface morphology. Additionally, preliminary results for immune-enhancing and anticancer activities reveal that these EPSs significantly induced the production of nitric oxide (NO), TNF-α, and IL-6 in Ana-1 cells and peritoneal macrophage cells. Meanwhile, the EPSs also significantly suppressed the proliferation of HCT-116, BCG-803, and particularly A-2780 cells. The results suggest that the three novel EPSs isolated from Lactobacillus pantheris TCP102 can be regarded as potential application value in functional food and natural antitumor drugs.

Oral Delivery of Novel Recombinant Lactobacillus Elicit High Protection against Staphylococcus aureus Pulmonary and Skin Infections.

Staphylococcus aureus is a leading cause of nosocomial and community-associated infection worldwide; however, there is no licensed vaccine available. S. aureus initiates infection via the mucosa; therefore, a mucosal vaccine is likely to be a promising approach against S. aureus infection. Lactobacilli, a non-pathogenic bacterium, has gained increasing interest as a mucosal delivery vehicle. Hence, we attempted to develop an oral S. aureus vaccine based on lactobacilli to cushion the stress of drug resistance and vaccine needs. In this study, we designed, constructed, and evaluated recombinant Lactobacillus strains synthesizing S. aureus nontoxic mutated α-hemolysins (HlaH35L). The results from animal clinical trials showed that recombinant Lactobacillus can persist for at least 72 h and can stably express heterologous protein in vivo. Recombinant L. plantarum WXD234 (pNZ8148-Hla) could induce robust mucosal immunity in the GALT, as evidenced by a significant increase in IgA and IL-17 production and the strong proliferation of T-lymphocytes derived from Peyer's patches. WXD234 (pNZ8148-Hla) conferred up to 83% protection against S. aureus pulmonary infection and significantly reduced the abscess size in a S. aureus skin infection model. Of particular interest is the sharp reduction of the protective effect offered by WXD234 (pNZ8148-Hla) vaccination in γδ T cell-deficient or IL-17-deficient mice. In conclusion, for the first time, genetically engineered Lactobacillus WXD234 (pNZ8148-Hla) as an oral vaccine induced superior mucosal immunity, which was associated with high protection against pulmonary and skin infections caused by S. aureus. Taken together, our findings suggest the great potential for a delivery system based on lactobacilli and provide experimental data for the development of mucosal vaccines for S. aureus.

Vaccine Composition Formulated with a Novel Lactobacillus-Derived Exopolysaccharides Adjuvant Provided High Protection against Staphylococcus aureus.

A vaccine that effectively targets methicillin-resistant Staphylococcus aureus (MRSA) is urgently needed, and has been the focus of studies by numerous research groups, but with limited success to date. Recently, our team found that exopolysaccharides derived from probiotic Lactobacilluscasei strain WXD030 as an adjuvant-formulated OVA could upregulate IFN-γ and IL-17 expression in CD4+ T cells. In this study, we developed a vaccine (termed rMntC-EPS) composed of S. aureus antigen MntC and Lactobacillus casei exopolysaccharides, which conferred high levels of protection against S. aureus infection. METHODS: Six-eight-week-old female mice were vaccinated with purified rMntC-EPS30. The immune protection function of rMntC-EPS30 was assessed by the protective effect of rMntC-EPS30 to S. aureus-induced pulmonary and cutaneous infection in mice, bacterial loads and H&E in injury site, and ELISA for inflammation-related cytokines. The protective mechanism of rMntC-EPS30 was assessed by ELISA for IgG in serum, cytokines in the spleen and lungs of vaccinated mice. In addition, flow cytometry was used for analyzing cellular immune response induced by rMntC-EPS30. For confirmation of our findings, three kinds of mice were used in this study: IL-17A knockout mice, IFN-γ knockout mice and TCRγ/δ knockout mice. RESULTS: rMntC-EPS30 conferred up to 90% protection against S. aureus pulmonary infection and significantly reduced the abscess size in the S. aureus cutaneous model, with clearance of the pathogen. The rMntC-EPS vaccine could induce superior humoral immunity as well as significantly increase IL-17A and IFN-γ production. In addition, we found that rMntC-EPS vaccination induced robust Th 17/γδ T 17 primary and recall responses. Interestingly, this protective effect was distinctly reduced in the IL-17A knockout mice but not in IFN-γ knockout mice. Moreover, in TCRγ/δ knockout mice, rMntC-EPS vaccination neither increased IL-17A secretion nor provided effective protection against S. aureus infection. CONCLUSIONS: These data demonstrated that the rMntC formulated with a novel Lactobacillus-derived Exopolysaccharides adjuvant provided high protection against Staphylococcus aureus. The rMntC-EPS vaccine induced γδ T cells and IL-17A might play substantial roles in anti-S. aureus immunity. Our findings provided direct evidence that rMntC-EPS vaccine is a promising candidate for future clinical application against S. aureus-induced pulmonary and cutaneous infection.

Lipo­prostaglandin E1 modifies cognitive impairment in rats with vascular cognitive impairment by promoting angiogenesis via the VEGF/VEGFR pathway.

The pathological mechanism of vascular cognitive impairment (VCI) involves ischemic lesions in the hippocampus. Prostaglandin E1 (PGE1) serves roles in the promotion of vascular endothelial growth factor (VEGF) expression, angiogenesis and enhances blood flow to ischemic regions. However, the effect of PGE1 on cognitive function in VCI rats and the underlying mechanism are unknown. In the current study, learning and memory function in VCI rats treated by lipo­PGE1 injection was assessed through Morris Water Maze test. Furthermore, the histological alterations, blood vessel numbers in the hippocampal CA1 region and relative VEGF protein and mRNA expression were researched. The results confirmed that VCI rats treated with lipo­PGE1 presented improved cognitive function, less neuronal cell loss, a greater number of blood vessels in the hippocampal region and higher VEGF protein and mRNA expression. However, the role of lipo­PGE1 in VCI rats can be inhibited by SU5416 (a specific VEGFR2 antagonist). The results indicated that lipo­PGE1 may alleviate cognitive deficits in VCI rats. The underlying mechanism may be associated with angiogenesis promoted by lipo­PGE1, which may involve the VEGF/VEGFR pathway. These findings may have therapeutic implications for cognitive impairment induced by hypoperfusion or chronic ischemic lesions.