Physical and antibacterial properties of bacterial cellulose films supplemented with cell-free supernatant enterocin-producing Enterococcus faecium TJUQ1.

In this study, a composite film was prepared with bacterial cellulose (BC) of Gluconacetobacter xylinus and cell-free supernatant (CFS) of Enterococcus faecium TJUQ1, which was named BC-E. The optimum conditions for the preparation of the composite film with a minimal antibacterial activity were the soak of BC in 80 AU/mL CFS for 6 h. By scanning electron microscope observation, the surface network structure of BC-E was denser than that of BC. The tensile strength of BC and BC-E was 4.65 ± 0.88 MPa and 16.30 ± 0.92 MPa, the elongation at break of BC and BC-E was 3.33 ± 0.89% and 31.60 ± 1.15%, respectively, indicating the mechanical properties of BC-E were significantly higher than that of BC (P < 0.05). The swelling ratio of BC-E (456.67 ± 7.20%) was lower than that of BC (1377.78 ± 9.07%), demonstrating BC-E films presented better water resistance. BC-E films were soaked with 320 AU/mL CFS, and then used to pack the ground meat with 6.55 log10 CFU/g of Listeria monocytogenes. After 8 days of storage, the number of bacteria decreased by 3.16 log10 CFU/g. Similarly, total mesophilic bacterial levels in the ground meat decreased by 2.41 log10 CFU/g compared to control groups.

Associations Among Self-rated Oral Health, Subjective Oral Conditions, Oral Health Behaviours, and Oral Healthrelated Quality of Life (OHRQoL).

PURPOSE: To evaluate the relationship between self-rated oral health, subjective oral conditions, oral health behaviours, and oral health-related quality of life (OHRQoL) in Chinese college students. MATERIALS AND METHODS: An online cross-sectional survey was conducted, inviting college students from eastern China to participate. A total of 1708 participants were included. A structural equation model was constructed to explain and assess the associations among self-rated oral health, subjective oral conditions, oral health behaviours, and OHRQoL. RESULTS: Self-rated oral health had a direct positive effect on subjective oral conditions and OHRQoL. Oral health behaviours had direct negative impacts on subjective oral conditions and OHRQoL as well as on tooth condition perception and oral health interventions. Subjective oral conditions had a direct positive effect on OHRQoL. There was a positive correlation between oral health behaviours and self-rated oral health. In addition, subjective oral conditions partially mediated both the effect of oral health behaviours on OHRQoL and the effect of self-rated oral health on OHRQoL. CONCLUSION: There were influential associations between self-rated oral health, subjective oral conditions, oral health behaviours, and OHRQoL among college students in eastern China. Making the most of their association can be a guide to radically improving the oral health of college students.

Characterization of antibacterial bacterial cellulose composite membranes modified with chitosan or chitooligosaccharide.

To synthesize biomaterials for antibacterial applications, chitosan (CS) and chitooligosaccharide (COS) were successfully incorporated into bacterial cellulose (BC) matrix respectively. The representative Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) were selected to evaluate the antibacterial effects of the composite membranes. The results manifested BC-CS and BC-COS membranes exhibited remarkable antibacterial properties against both bacteria with the inhibition ratio of 99.99 ±â€¯0.01% (S. aureus) and 99.99 ±â€¯0.01% (E. coli) for BC-CS, 99.64 ±â€¯0.18% (S. aureus) and 90.56 ±â€¯0.06% (E. coli) for BC-COS. The morphology obtained by scanning electron microscopy (SEM) showed BC-CS and BC-COS composite membranes possessed lower porosity and denser structure in comparison to pure BC. Moreover, in contrast with BC-CS, BC-COS performed better mechanical properties and also displayed stronger ABTS radical scavenging capacity of 92.62 ±â€¯2.85%. These results suggested that the development of BC-COS composite membrane would open up the possibility for the antibacterial applications in food and medical fields.

Malocclusion Generates Anxiety-Like Behavior Through a Putative Lateral Habenula-Mesencephalic Trigeminal Nucleus Pathway.

Malocclusion is an important risk factor for temporomandibular disorder (TMD), a series of disorders characterized by dysfunction in the orofacial region involving the temporomandibular joint (TMJ) and jaw muscles. We recently showed that experimental unilateral anterior crossbite (UAC) produced masseter hyperactivity through a circuit involving the periodontal proprioception, trigeminal mesencephalic nucleus (Vme), and trigeminal motor nucleus (Vmo). Anxiety is a common complication in patients with TMD. The lateral habenula (LHb) is involved in emotional modulation and has direct projections to the Vme. Therefore, the present research examined whether UAC facilitates excitatory input from the LHb to the Vme and, subsequently, anxiety-like behaviors in rats. The LHb activation was evaluated by the electrophysiological recording, assessment of vesicular glutamate transporter-2 (VGLUT2) mRNA expression, and measurement of anxiety-like behaviors. The effects of LHb activity on Vme were evaluated by electrophysiological recording from Vme neurons and local changes in VGLUT2 protein density. UAC produced anxiety in modeled rats and increased neuronal activity in the LHb. VGLUT2 mRNA expression was also increased in the LHb. Further, VGLUT2-positive boutons were observed in close apposite upon parvalbumin (PV)-labeled Vme neurons. VGLUT2 protein expression was also increased in the Vme. Significantly, injection of VGLUT2-targeted shRNA into the LHb reduced the expression of VGLUT2 protein in the Vme, attenuated UAC-associated anxiety-like behaviors, and attenuated electrophysiological changes in the Vme neurons. In conclusion, we show that UAC activates the LHb neurons as well as the periodontal proprioceptive pathway to provide excitatory input to the Vme and produce anxiety in rats. These findings provide a rationale for suppressing activity of the LHb to attenuate both the physical and psychological effects of TMD.