A chlorogenic acid-chitosan complex bifunctional coating for improving osteogenesis differentiation and bactericidal properties of zirconia implants.

Poor osteogenesis caused by limited bioactivity and peri-implantitis caused by bacterial colonization are the main challenges affecting the use of zirconia-based materials in dental implants. Accordingly, the development of a surface treatment method with an antibacterial effect and that promotes osteogenesis without damage to cells is crucial for yttrium-stabilized tetragonal zirconia (Y-TZP) implants. Herein, we have developed a functional surface modification strategy whereby a poly (ethylene imine)/hyaluronic acid /chitosan-chlorogenic acid (PEI/HA/CGA-CS) conjugate is deposited on a zirconia surface by the layer-by-layer (LBL) technique, enhancing its osteogenic differentiation and antibacterial activities. The results showed that the PEI/HA/CGA-CS coating improved the wettability of the zirconia surface and maintained stable release of CGA. The PEI/HA/CGA-CS functional coating was found to promote early cell adhesion, proliferation, differentiation, and calcification. The results of bacterial adhesion and activity tests showed that the coating effectively inhibits the proliferation and activity of Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) without impairing the biological activity of osteoblasts. In addition, we found that the PEI/HA/CGA-CS coating enhances the osteogenesis of MC3T3-E1 cells by promoting the protein expression of Nephronectin (NPNT) and activating the Wnt/ß-catenin signaling pathway. The above results are of profound significance for the practical application of zirconia-based implants. DATA AVAILABILITY: Data will be made available on request.

Development of genomic resources for Wenchengia alternifolia (Lamiaceae) based on genome skimming data.

Wenchengia alternifolia (Lamiaceae), the sole species of the genus Wenchengia is extremely rare and is currently listed as Critically Endangered (CR) on the IUCN Red List. The species had long been considered endemic to Hainan Island, China and was once believed to be extinct until a small remnant population was rediscovered at the type locality in 2010. Four more populations were later found on Hainan and in Vietnam. In order to develop genomic resources for further studies on population genetics and conservation biology of this rare species, we identified infraspecific molecular markers in the present study, using genome skimming data of five individuals collected from two populations on Hainan Island and three populations in Vietnam respectively. The length of plastome of the five individuals varied from 152,961 bp to 150,204 bp, and exhibited a typical angiosperm quadripartite structure. Six plastid hotspot regions with the Pi > 0.01 (trnH-psbA, psbA-trnK, rpl22, ndhE, ndhG-ndhI and rps15-ycf1), 1621 polymorphic gSSRs, as well as 1657 candidate SNPs in 237 variant nuclear genes were identified, thereby providing important information for further genetic studies.

Molecular Detection of Zoonotic and Veterinary Pathogenic Bacteria in Pet Dogs and Their Parasitizing Ticks in Junggar Basin, North-Western China.

Despite the recognized epidemiological importance of ticks as vectors for pathogens that cause numerous zoonotic and veterinary diseases, data regarding the pathogens of pet dogs and their parasitic ticks in the Junggar Basin are scarce. In this study, a total of 178 blood samples and 436 parasitic ticks were collected from pet dogs in Junggar Basin, Xinjiang Uygur Autonomous Region (XUAR), north-western China. All ticks were identified as Rhipicephalus turanicus sensu stricto (s.s.) according to morphological and molecular characteristics. Rh. turanicus s.s. ticks were collected from pet dogs in China for the first time. Seven tick-borne pathogens, such as Ehrlichia chaffeensis, Anaplasma phagocytophilum, Rickettsia massiliae, Candidatus R. barbariae, Brucella spp., Rickettsia sibirica, and Anaplasma ovis, were detected from ticks, whereas the first five bacteria were detected from blood samples of dogs. Brucella spp. was the most predominant pathogen in both blood samples and ticks of pet dogs, with the detection rates of 16.29 and 16.74%, respectively. Moreover, 17 ticks and 1 blood sample were co-infected with two pathogens, and 1 tick was co-infected with three pathogens. This study provided molecular evidence for the occurrence of Anaplasma spp., Ehrlichia spp., Rickettsia spp., and Brucella spp. circulating in pet dogs and their parasitic ticks in Junggar Basin, north-western China. These findings extend our knowledge of the tick-borne pathogens in pet dogs and their parasitic ticks in Central Asia; therefore, further research on these pathogens and their role in human and animal diseases is required.

The roles of 10-methacryloyloxydecyl dihydrogen phosphate and its calcium salt in preserving the adhesive-dentin hybrid layer.

OBJECTIVES: 10-Methacryloyloxydecyl dihydrogen phosphate (MDP) has been regarded as the most effective dentin-bonding monomer for more than 20 years. Although the dentin-bonding promoting effect of MDP has been well demonstrated, the mechanisms by which it benefits the stably of collagen within the adhesive-dentin hybrid layer are not currently fully understood. The objective of this study was to investigate the roles of MDP and its calcium salt in preserving the adhesive-dentin hybrid layer. METHODS: MDP-conditioned collagen was investigated by Fourier-transform infrared spectroscopy, Ultraviolet-visible spectroscopy, and molecular docking. The structural changes to the dentin surface upon acid-etching and MDP-conditioning were observed by SEM. X-ray diffraction and nuclear magnetic resonance were used to investigate the chemical interactions between MDP and HAp. The collagen-protecting effects of MDP and its Ca salt were investigated using in-situ zymography, rhMMP-9 colorimetric assay, hydroxyproline assay, and molecular docking. RESULTS: MDP forms a stable collagen-phosphate complex through hydrogen bonding with the collagen in dentin. Furthermore, it generates MDP-Ca salts that are deposited on the dentin collagen scaffold, protecting it from degradation. Moreover, both free MDP and the MDP-Ca salt inhibit matrix metallopeptidase and exogenous proteases, with the inhibitory effect of the calcium salt being significantly stronger than that of the free form. SIGNIFICANCE: MDP-based adhesives preserve the collagen within the hybrid layer by simultaneously improving collagen's resistance to exogenous enzymes and inhibiting MMP activity, both of which contribute to the longevity of dentin-resin bonding.

Characterization and biocompatibility analysis of different silanes coupling c(RGDfK) cyclic peptide on titanium surfaces / 口腔疾病防治

Objective@#To compare the efficiency and biocompatibility of four different silanes on immobilizing c(RGDfK) peptide on titanium surface.@*Methods @# After alkali-heat treatment (group OH), the titanium surface was treated with 3-aminopropyltriethoxysilane (APTES) (group OHAP), 3-chloropropyltriethoxysilane (CPTES) (group OHCP) (3-mercaptopropyltrimethoxysilane (MPTS) (group OHMPT) and 3-isobutyryloxy propyltrimethoxysilane(γ- MPS) (group OHMPS) to immobilize the c(RGDfK) cyclic peptide and constructa titanium-silane-c(RGDfK) coating. The NT group was the blank control group. The surface morphology and wettability of the coatings were detected using scanning electron microscopy and contact angle measurement. The elemental composition of the titanium surface was analyzed using X-ray photoelectron spectroscopy. After fluorescent staining with 4’,6-diamino-2-phenylindole (DAPI) and phalloidin, the adhesion of mouse preosteoblast MC3T3-E1 cells on the surface of the materials was observed using laser confocal microscopy. Cell counting kit-8 (CCK-8) and alkaline phosphatase (ALP) activity assays were used to evaluate the proliferation and osteogenic differentiation of MC3T3-E1 cells on the surface of the materials, respectively. @*Results @#Scanning electron microscope observation showed a spongy-like 3-dimensional network formed on the titanium surface after alkali-heat treatment with silane-c(RGDfK) coating adhesion. The wettability of each group was greatly improved compared to the untreated titanium surface. The element ratios of Si/Ti and amide-N/Ti in the OHMPS group were the highest. The OHAP group exhibited the best cell adhesion effect. The cell proliferation and ALP activity of the OHAP, OHMPT, and OHMPS groups were significantly higher than the control group (P <0.05); there was no statistical difference between the OHCP group and the control group.@*Conclusion @#MPTS, CPTES and γ-MPS covalently immobilized cyclic peptide c(RGDfK) on the titanium surface, which promoted adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells. Theγ-MPS conjugated C (RGDfK)cyclic peptide exhibited the best effect. MPTS, CPTES and γ-MPS coupled with c(RGDfK) cyclic peptides had similar biological properties.