No abstract

Stomata control gas exchange and water transpiration and are one of the most important physiological apparatuses in higher plants. The regulation of stomatal aperture is closely coordinated with photosynthesis, nutrient uptake, plant growth, development, and so on. With advances in scanning electron microscopy (SEM), high-resolution images of plant stomata and cell surfaces can be obtained from detached plant tissues. However, this method does not allow for rapid analysis of the dynamic variation of plant stomata and cell surfaces in situ under nondestructive conditions. In this study, we demonstrated a novel plant surface impression technique (PSIT, Silagum-Light as correction impression material based on A-silicones for all two-phase impression techniques) that allows for precise analysis of plant stomata aperture and cell surfaces. Using this method, we successfully monitored the dynamic variation of stomata and observed the nanoscale microstructure of soybean leaf trichomes and dragonfly wings. Additionally, compared with the analytical precision and the time used for preparing the observation samples between PSIT and traditional SEM, the results suggested that the analytical precision of PSIT was the same to traditional SEM, but the PSIT was more easy to operate. Thus, our results indicated that PSIT can be widely applied to the plant science field.

Periodontitis is a chronic inflammatory disease characterized by loss of attachment and destruction of the periodontium. Decellularized sheet, as an advanced tissue regeneration engineering biomaterial, has been researched and applied in many fields, but its effects on periodontal regeneration remain unclear. In this study, the biological properties of decellularized human periodontal ligament cell (dHPDLC) sheets were evaluated in vitro. Polycaprolactone/gelatin (PCL/GE) nanofibers were fabricated as a carrier to enhance the mechanical strength of the dHPDLC sheet. 15-deoxy- Δ 12 , 14 -prostaglandin J2 (15d-PGJ2) nanoparticles were added for anti-inflammation and regeneration improvement. For in vivo analysis, dHPDLC sheets combined with 15d-PGJ2 nanoparticles, with or without PCL/GE, were implanted into rat periodontal defects. The periodontal regeneration effects were identified by microcomputed tomography (micro-CT) and histological staining, and immunohistochemistry. The results revealed that DNA content was reduced by 96.6%. The hepatocyte growth factor, vascular endothelial growth factor, and basic fibroblast growth factor were preserved but reduced. The expressions or distribution of collagen I and fibronectin were similar in dHPDLC and nondecellularized cell sheets. The dHPDLC sheets maintained the intact structure of the extracellular matrix. It could be recellularized by allogeneic human periodontal stem ligament cells and retain osteoinductive potential. Newly formed bone, cementum, and PDL were observed in dHPDLC sheets combined with 15d-PGJ2 groups, with or without PCL/GE nanofibers, for four weeks post-operation in vivo. Bringing together all these points, this new construct of dHPDLC sheets can be a potential candidate for periodontal regeneration in an inflammatory environment of the oral cavity.

The aim was to study the characteristics of lateral mandibular horizontal deviations during opening-closing movements and their association with TMJ sounds of the clicking type. Subjects were 28 healthy volunteers and 38 patients diagnosed with MRI imaging as having TMJ disc dysfunction, 22 with disc displacement without (DD) and 16 as having disc displacement with reduction (DDR). TMJ sounds were recorded with miniature microphones placed in the ear canals, and jaw movements were documented with a kinesiograph. A sign, unbalanced lateral deviation (ubd) was defined as a rapid, short duration, change in jaw movement direction from, and back to, a smooth deviation path in the horizontal plane. The hypotheses were that degrees of maximal deviations, proportions of unbalanced deviation (ubd) and such deviation associated with TMJ sounds (ubdS), differ between healthy subjects and patients with DD or DDR. Comparisons between groups were made using one-way anova and chi-square analysis, as appropriate. No differences were found between groups regarding degree of lateral deviation per se. The proportions of ubd and ubdS were significantly higher in patients with DDR than in healthy subjects and than in patients with DD (P < 0·001), but no such differences were found between healthy subjects and patients with DD. For prediction of DDR, the sensitivity and specificity of the sign ubdS were found to be 68·8% and 89·3%, respectively. For the sign ubd, they were 100·0% and 64·3%. This indicates that the sign ubdS has diagnostic value in screening for DDR.

Objective and Background Recently, decellularized matrix (DCM) is considered as a new biomaterial for tissue regeneration. To explore the possible application of DCM in periodontal regeneration, the effect of DCM from three different cells on the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs) was investigated. Methods DCM derived from human periodontal ligament cells (PDLCs), dental pulp cells (DPCs), and gingival fibroblasts (GFs) were fabricated using Triton X‐100/NH4OH combined with DNase I. Allogeneic PDLSCs were cultured on PDLC‐DCM, DPC‐DCM, and GF‐DCM, respectively. The proliferative capacity of PDLSCs was evaluated by PicoGreen assay kit. The expression of alkaline phosphatase (ALP), runt‐related transcription factor‐2 (RUNX2), osteocalcin (OCN), collagen I (COL1), periostin (POSTN), and cementum protein 1 (CEMP1) were detected by qRT‐PCR and western blotting. Results PDLC‐DCM, DPC‐DCM, and GF‐DCM had similar and integrated networks of extracellular matrix, as well as significantly decreased DNA content. Compared with control group in which PDLSCs were directly seeded in culture plates, PDLC‐DCM, DPC‐DCM, and GF‐DCM promoted the proliferation of re‐seeded PDLSCs. Additionally, PDLSCs on DCM exhibited higher mRNA and protein expression levels of ALP, RUNX2, OCN, and COL1. The expression of POSTN in PDLC‐DCM group was significantly higher than control group at both mRNA and protein levels. Conclusions PDLC‐DCM, DPC‐DCM, and GF‐DCM could enhance the proliferation of PDLSCs. PDLC‐DCM facilitated osteogenic differentiation and periodontal ligament differentiation of PDLSCs, while DPC‐DCM and GF‐DCM promoted osteogenic differentiation.