Oral infection with periodontal pathogens induced chronic obstructive pulmonary disease-like lung changes in mice.

BACKGROUND: Epidemiological studies have demonstrated that periodontitis is an independent risk factor for chronic obstructive pulmonary disease (COPD). However, the mechanism underlying the association between these two diseases remains unclear. The lung microbiota shares similarities with the oral microbiota, and there is growing evidence to suggest that the lung microbiome could play a role in the pathogenesis of COPD. This study aimed to investigate whether periodontal pathogens could contribute to the pathogenesis of COPD in a mouse model. METHODS: We established mouse models with oral infection by typical periodontal pathogens, porphyromonas gingivalis (Pg group) or fusobacterium nucleatum (Fn group), over a three-month period. Mice that did not receive oral infection were set as the control group (C group). We assessed the level of alveolar bone resorption, lung function, and histological changes in the lungs of the mice. Additionally, we measured the levels of inflammatory factors and tissue damage associated factors in the lung tissues. RESULTS: Lung function indices, including airway resistance, peak inspiratory/expiratory flow and expiratory flow-50%, were significantly reduced in the Fn group compared to the C group. Additionally, histological examination revealed an increased number of inflammatory cells and bullae formation in the lung tissue sections of the Fn group. Meanwhile, levels of inflammatory factors such as IL-1ß, IL-6, IFN-γ, and TNF-α, as well as tissue damage associated factors like matrix metalloproteinase-8 and neutrophil elastase, were significantly elevated in the lung tissue of the Fn group in comparison to the C group. The Pg group also showed similar but milder lung changes compared to the Fn group. Pg or Fn could be detected in the lungs of both oral infected groups. CONCLUSION: The results indicated that oral periodontal pathogens infection could induce COPD-like lung changes in mice, and they may play a biological role in the association between periodontitis and COPD.

Role of experimental periodontitis in inducing pulmonary inflammation in mice.

OBJECTIVE: The aim of the study was to explore the potential role of experimental periodontitis in pulmonary inflammation in mice. MATERIALS AND METHODS: Mice were divided into control, ligature-induced periodontitis (L) and ligature plus Porphyromonas gingivalis (P. gingivalis)-induced periodontitis (LPG) groups. Alveolar bone resorption, pulmonary function, lung tissue histology and cytokine expression were examined at 2, 4 and 8 weeks. Then cytokines and neutrophils in the peripheral blood and lung tissue were further assessed at 8 weeks to determine the role of cytokines induced by LPG periodontitis, and the effect of P. gingivalis was evaluated using P. gingivalis-IgG and P. gingivalis gingipain. RESULTS: Alveolar bone resorption was more severe in the L and LPG groups. However, pulmonary inflammation was observed only in the LPG group at 8 weeks when cytokines and neutrophils in the peripheral blood and lung tissue were the most significant elevation, along with higher levels of P. gingivalis-IgG and P. gingivalis gingipain. Cytokine levels were also increased in the gingival tissue, peripheral blood and lung tissue in the L group, accompanied by elevated peripheral blood neutrophils, but not as significantly as that in the LPG group. CONCLUSIONS: LPG periodontitis can trigger pulmonary inflammation over the long term, in which cytokines and P. gingivalis play an important role.

Difference in oral microbial composition between chronic periodontitis patients with and without diabetic nephropathy.

BACKGROUND: To investigate the difference in the structural composition of salivary flora between chronic periodontitis patients with and without diabetic nephropathy (DN). METHODS: Thirty salivary samples of 15 chronic periodontitis patients with DN (DN group) and 15 chronic periodontitis patients with diabetes but without DN (DM group) were subjected to pyrosequencing of polymerase chain reaction-amplified 16 s ribosomal RNA genes. After diversity testing, the differential flora were analyzed. The sequencing results were compared with GenBank database to determine the type of differential flora using species composition analysis, hierarchical cluster analysis, principal co-ordinate analysis, and species difference analysis. RESULTS: There were significant between-group differences with respect to Gemella, Selenomonas spp, Lactobacillales_unclassified, Bacteria-unclassified and Abiotrophia (p < 0.05). Compared with DM group, the relative abundance of Selenomonas spp. in DN group was significantly higher; the area under the receiver operating characteristic curve of Selenomonas spp. was 0.713 (P < 0.05). Multi-level biological identification and feature maps indicated that Selenomonas spp. might be used as a potential biomarker for DN patients. On binary logistic regression analysis, increase of Selenomonas spp. was related with DN. CONCLUSIONS: We found significant between-group differences in the structural composition of oral flora. The increase in the relative abundance of Selenomonas spp. may be associated with DN in patients with chronic periodontitis.

A study on the performance, structure, composition, and release behavior changes of polybutylene adipate terephthalic acid (PBAT) film during food contact.

Polybutylene adipate terephthalic acid (PBAT) is an emerging biodegradable material in food packaging. However, concerns have been raised regarding the potential hazards it could pose to food safety. In this study, the changes of PBAT films during food contact and the release of small molecules were inestigated by a multiscale approach. On a macro-scale, the surface roughness of the films increased with the reduction in the concentration of food simulants and the increase in contact temperatures, especially after immersion in acidic food environments. On a micro-scale, the crystallinity (Xc) and degradation indexes (DI) of the films increased by 5.7-61.2% and 7.8-48.6%, respectively, which led to a decrease in thermal stability. On a scale approaching the molecular level, 2,4-di-tert-butylphenol (2,4-DTBP) was detected by gas chromatography-mass spectrometry (GC-MS/MS) with the highest migration content, and the release behavior of 2,4-DTBP was further investigated by migration kinetics. In addition, terephthalic acid (TPA), a hydrolysis product of PBAT, was detected in acidic food environments by liquid chromatography-mass spectrometry (LC-MS/MS). The results of this study could provide practical guidance and assistance to promote sustainable development in the field of food packaging.

Chronic Periodontitis is a Risk Factor of Renal Dysfunction in Patients with Type 2 Diabetes.

BACKGROUND: This study explores the association between chronic periodontitis and renal dysfunction in type 2 diabetic mellitus (T2DM) patients. METHODS: An observational study was conducted in 169 T2DM patients with chronic periodontitis. Patients were divided into 2 groups according to presence of normal renal function (n=111) and renal dysfunction (n=58), and oral health behavior-related variables were obtained by questionnaire. Periodontal status was examined, and pocket probing depth (PD), clinical attachment level (CAL), and bleeding index (BI) were measured. RESULTS: The severe periodontitis group had a significant higher HbA1c level (8.53 ± 1.61%) as compared with the mild and moderate periodontitis groups (7.68±1.58%) and (7.35±1.45%), P=0.001. Compared with patients with normal renal function, patients with renal dysfunction had a higher PD value, higher CAL value, fewer remaining teeth, and were less likely to have remaining teeth ≥20. The percentage of sites with PD ≥4 mm (52.8% vs. 41.67%) was significantly greater in patients with renal dysfunction. There was no difference in the scores of oral health knowledge assessment between the 2 groups. After adjustment by gender, age, BMI, smoking, hypertension, and HbA1c, the percentage of the sites with PD≥4 mm was an independent risk factor of renal dysfunction in T2DM patients. CONCLUSION: In patients with T2DM, those with periodontitis may be more susceptible to decreased kidney function.

Periodontal Status and Microbiologic Pathogens in Patients with Chronic Obstructive Pulmonary Disease and Periodontitis: A Case-Control Study.

Purpose: To evaluate clinical periodontal status and microbiologic pathogens in patients with chronic obstructive pulmonary disease (COPD) and periodontitis. Patients and Methods: We conducted a case-control study of 60 periodontitis patients with COPD (case group) and 60 periodontitis patients with normal pulmonary function (control group). Their periodontal status and respiratory function were clinically examined. Real-time polymerase chain reaction assays were used to measure five dental pathogens and four respiratory pathogens in subgingival dental plaque. Spearman's rank correlation coefficients (r2) were calculated to assess correlations of pathogens. Principal component analysis (PCA) was employed to assess the similarity of bacterial diversity between the two groups. Logistic regression was performed to examine the associations of periodontal variables and pathogens with COPD risk. Results: COPD patients had fewer remaining teeth, higher plaque index (PLI), and more severe site percentages of clinical attachment level (CAL) than the controls. Although COPD patients tended to have relatively higher ranked means of Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, and Haemophilus influenza than control participants, the differences were not significant. Some periodontal pathogens and respiratory pathogens were positively correlated with each other (r2 =0.29 to 0.47, all P < 0.05). The PCA graph showed that the distributions of pathogens were more dispersed but less discriminated in the COPD group than those in the control group. PLI (P = 0.045) and CAL ≥ 5mm site percentages (P = 0.01) were significantly associated with an increased risk of COPD, while pathogens were not associated with COPD. Conclusion: Our results from this study do not indicate periodontal pathogens as potential predictors of COPD risk, despite significantly poor periodontal status associated with COPD.

Bio-inspired Polydopamine Surface Modification of Nanodiamonds and Its Reduction of Silver Nanoparticles.

Surface functionalization of nanodiamonds (NDs) is still challenging due to the diversity of functional groups on the ND surfaces. Here, we demonstrate a simple protocol for the multifunctional surface modification of NDs by using mussel-inspired polydopamine (PDA) coating. In addition, the functional layer of PDA on NDs could serve as a reducing agent to synthesize and stabilize metal nanoparticles. Dopamine (DA) can self-polymerize and spontaneously form PDA layers on ND surfaces if the NDs and dopamine are simply mixed together. The thickness of a PDA layer is controlled by varying the concentration of DA. A typical result shows that a thickness of ~5 to ~15 nm of the PDA layer can be reached by adding 50 to 100 µg/mL of DA to 100 nm ND suspensions. Furthermore, the PDA-NDs are used as a substrate to reduce metal ions, such as Ag[(NH3)2]+, to silver nanoparticles (AgNPs). The sizes of the AgNPs rely on the initial concentrations of Ag[(NH3)2]+. Along with an increase in the concentration of Ag[(NH3)2]+, the number of NPs increases, as well as the diameters of the NPs. In summary, this study not only presents a facile method for modifying the surfaces of NDs with PDA, but also demonstrates the enhanced functionality of NDs by anchoring various species of interest (such as AgNPs) for advanced applications.

[Preparation of a decellularized scaffold derived from human liver tissue].

OBJECTIVE: To develop a method for preparing a decellularized scaffold based on human liver tissue. METHODS: A surgical specimen of the left lateral lobe of the liver was obtained from a patients with hepatic hemangioma. The decellularization process was performed by repeated freezing-thawing, sequential perfusion with 0.01% SDS, 0.1% SDS and 1% Triton X-100 through the portal vein, and sterilization with peracetic acid. L-02 cells were then engrafted onto the decellularized liver scaffold. RESULTS: HE staining, DAPI staining and scanning electron microscopy all verified the absence of residual cellular components in the decellularized scaffold. The residual DNA content in the decellularized scaffolds was 25.3∓14.6 ng/mg (dry weight), which was less than 1% of the total DNA content in a fresh human liver. Immunohistochemistry demonstrated that type I and IV collagens, fibronectin and elastin were all retained in the scaffold. The engrafted L-02 cells survived well on the scaffold with active proliferation and expressed albumin and G6pc. CONCLUSION: It is feasible to prepare decellularized scaffolds using surgical specimens of human liver, which can be a new approach to constructing a tissue-engineered liver for clinical purposes.

PX DNA triangle oligomerized using a novel three-domain motif.

Structural DNA nanotechnology is directed at building objects, lattices, and arrays from cohesive interactions between DNA molecules. The predominant means of doing this takes advantage of the information inherent in Watson-Crick base pairing in duplex formation and in sticky-ended cohesion. Nevertheless, other forms of nucleic acid cohesion are also known, particularly paranemic edge-sharing interactions (PX). Here we report the formation of a triangular species that has four strands per edge, held together by PX interactions. We demonstrate by nondenaturing gel electrophoresis and by atomic force microscopy (AFM) that we can combine a partial triangle with other strands to form a four-stranded molecule that is robust. By combining them with a new mixed-fusion type of three-domain molecule, we demonstrate by AFM that these triangles can be self-assembled into a linear array.