Association Between Oral Health and Cognitive Impairment in Older Adults: Insights from a Six-Year Prospective Cohort Study.

OBJECTIVE: This study aims to investigate the relationships between four baseline oral conditions (periodontal status, dental caries, tooth wear, and dentition) and repeated global cognition or domain-specific cognition (memory, executive function, attention, and verbal fluency) in non-demented older adults over time. METHODS: This prospective cohort study (2011-2019) enrolled 516 non-demented community-dwelling older adults (age ≥ 65) to explore the association between oral health and cognitive function. Global and domain-specific cognition were assessed biennially (four repeats) using a battery of neuropsychological tests. The baseline oral health conditions were examined, including periodontal status, dental caries, tooth wear, and dentition. The association of these oral conditions with cognition was evaluated by generalized linear mixed models. Stratified analyses were performed by important covariates. RESULTS: Over time, dental caries was associated with poor memory in two different logical memory tests (ß^= -0.06 and ß^= -0.04). Incomplete dentition with less than 28 teeth was associated with poor performance in attention (ß^= -0.05) and verbal fluency (ß^= -0.03). These associations became more evident in those with an elevated inflammatory marker (IL-6, ß^= -0.11 to -0.08). In contrast, tooth wear was associated with better memory in two different logical memory tests (ß^= 0.33 and ß^= 0.36) and better executive function (ß^= 0.06) over time, and this association became more evident in those with the lowest inflammatory marker (IL-6, ß^= 0.10). CONCLUSIONS: Dental caries and incomplete dentition were associated with poor memory, attention, and verbal fluency performance. Conversely, tooth wear was associated with better memory performance and executive function. CLINICAL SIGNIFICANCE: For early prevention of dementia, an evaluation of multiple dental and periodontal status in older adults helps predict the risk of dementia in the preclinical phase. Maintaining intact tooth structure without caries progression and eventually tooth loss may help prevent the worsening of memory, attention, and verbal fluency over time.

The temporospatial relationship between mouse dental pulp stem cells and tooth innervation.

Background/purpose: Dental pulp stem cells (DPSCs) exhibit versatile differentiation capabilities, including neural differentiation, prompting the hypothesis that they may be implicated in the neurodevelopment of teeth. This study aimed to explore the temporospatial dynamics between DPSCs and tooth innervation, employing immunofluorescence staining and fluorescent dye injections to investigate the distribution of DPSCs, neural stem cells (NSCs), nerve growth cones, and sensory nerves in developing mouse tooth germs at various stages. Materials and methods: Immunofluorescence staining targeting CD146, Nestin, and GAP-43, along with the injection of AM1-43 fluorescent dye, were utilized to observe the distribution of DPSCs, NSCs, nerve growth cones, and sensory nerves in mouse tooth germs at different developmental stages. Results: Positive CD146 immunostaining was observed in microvascular endothelial cells and pericytes within and around the tooth germ. The percentage of CD146-positive cells remained consistent between 4-day-old and 8-day-old second molar tooth germs. Conversely, Nestin expression in odontoblasts and their processes decreased in 8-day-old tooth germs compared to 4-day-old ones. Positive immunostaining for GAP-43 and AM1-43 fluorescence revealed the entry of nerve growth cones and sensory nerves into the pulp in 8-day-old tooth germs, while these elements were confined to the dental follicle in 4-day-old germs. No co-localization of CD146-positive DPSCs with nerve growth cones and sensory nerves was observed. Conclusion: DPSCs and NSCs were present in dental pulp tissue before nerves penetrated the pulp. The decline in NSCs after nerve entry suggests a potential role for DPSCs and NSCs in attracting neural growth and/or differentiation within the pulp.

Interactions of neural-like cells with 3D-printed polycaprolactone with different inner diameters for neural regeneration.

Background/purpose: Peripheral neural regeneration is an interesting and challenging field. The aim of this study was to investigate the interactions of neural-like PC12 cells and Poly-D-Lysine (PDL)-coated 3D-printed polycaprolactone (PCL) scaffolds with different inner diameters of half tubular array (HTA) (0, 200, 300, and 400 µm), respectively. Materials and methods: This study used the fused deposition modeling (FDM) technique with 3D-printing to fabricate the thermoplastic polymer. Scaffold properties were measured by mechanical testing, and coating quality was observed under a scanning electron microscope (SEM). PC12 cell biocompatibility was examined by an MTT assay. Cell differentiation was evaluated by immunofluorescence staining. Results: The cell viability of PC12 cells on PDL-coated PCL scaffolds with a 200-µm inner diameter of HTA was shown with significant differences (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001) than other PCL groups at all experimental dates. The SEM observation showed that PDL-coated PCL scaffolds with 200-µm inner diameters of HTA promoted cell adhesion. An immunofluorescence staining of PC12 cells on the PDL-coated PCL scaffold with a 200-µm inner diameter of the HTA group showed that it stimulated PC12 cells for neurite formation much better than the other groups.A PDL-coated PCL scaffold with a 200-µm inner diameter of HTA can promote the growth and differentiation of PC12 cells better than other groups. It indicated that PDL-coated PCL scaffolds with a 200-µm inner diameter HTA can be used for further neural regeneration application.

3D-printed polycaprolactone scaffolds coated with beta tricalcium phosphate for bone regeneration.

BACKGROUND/PURPOSE: 3D-printing technology is an important tool for the bone tissue engineering (BTE). The aim of this study was to investigate the interaction of polycaprolactone (PCL) scaffolds and modified mesh PCL coated with beta TCP (PCL/ß-TCP) scaffolds with MG-63. METHODS: This study used the fused deposition modeling (FDM) technique with the 3D printing technique to fabricate the thermoplastic polymer and composite scaffolds. Scaffold structure and coating quality were observed under a scanning electron microscope (SEM). MG-63 cells were injected and attached to the mesh-manufactured PCL scaffolds. The biocompatibility of mesh structured PCL and PCL/ß-TCP scaffolds could be examined by measuring the viability of MG-63 cells of MTT assay. Bone cell differentiation was evaluated ALP activity by mineralization assay. RESULTS: The results showed that both mesh PCL scaffolds and PCL/ß-TCP scaffolds were non-toxic to the cells. The ALP activities of cells in PCL/ß-TCP scaffolds groups were significant differences and better than PCL groups in all groups at all experimental dates. The mineralization process was time-dependent, and significantly higher mineralization of osteosarcoma cells was observed on PCL/ß-TCP scaffolds at experimental dates. CONCLUSION: We concluded that both meshes structured PCL and PCL/ß-TCP scaffolds could promote the MG-63 cell growth, and PCL/ß-TCP was better than the PCL scaffolds for the outcome of MG63 cell differentiation and mineralization.

Action of econazole on Ca2+ levels and cytotoxicity in OC2 human oral cancer cells.

Background/purpose: Econazole is an antifungal drug. Antifungal activity of econazole against non-dermatophyte molds was reported. Econazole inhibited Ca2+ channels and stimulated cytotoxicity in lymphoma and leukemia cells. Ca2+ cations are crucial second envoy that triggers various processes. This research was aimed to investigate action of econazole on Ca2+ levels and cytotoxicity in OC2 human oral cancer cells. Materials and methods: Cytosolic Ca2+ levels ([Ca2+]i) were detected employing fura-2 as a probe in a RF-5301PC spectrofluorophotometer (Shimadzu). Cytotoxicity was determined using 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] (WST-1) to detect fluorescence changes. Results: Econazole at 10-50 µmol/L provoked [Ca2+]i raises. Forty % of 50 µml//L econazole-induced signal was diminished when external Ca2+ was eliminated. The Ca2+ influx provoked by econazole was suppressed by different degrees by store-induced Ca2+ influx suppressors SKF96365 and nifedipine; GF109203X (a protein C [PKC] inhibitor); an extracellular signaling pathway (ERK) 1/2 blocker PD98059, and phospholipase A2 suppressor aristolochic acid, but was enhanced by phorbol 12-myristate 13 acetate (PMA; a PKC activator) by 18%. Without external Ca2+, econazole-caused [Ca2+]i raises were abolished by thapsigargin. In contrast, econazole partially suppressed the [Ca2+]i raises caused by thapsigargin. U73122 fell short to change econazole-caused [Ca2+]i responses. Econazole (10-70 µmol/L) elicited cytotoxicity in a dose-dependent fashion. Blockade of 50 µmol/L econazole-induced [Ca2+] rises with BAPTA/AM enhanced econazole-induced cytotoxicity by 72%. Conclusion: Econazole evoked [Ca2+]i raises and provoked cytotoxicity in a concentration-dependent manner in OC2 human oral cancer cells. In Ca2+-containing solution, BAPTA/AM enhanced 50 µmol/L econozole-induced cytotoxicity.

Efficacy of polyacrylate silver salt/polyvinylpyrrolidone-based liquid oral gel in management of concurrence chemoradiotherapy-induced oral mucositis.

BACKGROUND/PURPOSE: Acute oral mucositis (OM) is a painful complication of concurrent chemoradiotherapy (CCRT). This severe adverse symptom may impact on patient's quality of life, lead to malnutrition. Thus, finding more effective methods in OM management is very important. The purpose of this study is to evaluate the efficacy of polyacrylate silver salt/Polyvinylpyrrolidone-based liquid oral gel (named as polyacrylate silver salt oral gel) in improving the symptomatic relief of CCRT-induced oral mucositis and oral dysfunction in neck and head cancer patients. METHODS: In this study, 24 oral cancer patients underwent CCRT and having OM grade 2 or higher were randomly assigned into the test group and the control group. Both groups followed Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) clinical practice guidelines for the management of mucositis, but adding rinsing with 15 g oral gel right after oral hygiene treaded the test group. Clinical OM and oral function were assessed weekly for 4 consecutive weeks till 5-10 days after the completion of radiotherapy. For evaluation, Common Terminology Criteria for Adverse Events (CTCAE) v3.0 was used for collecting the data of OM grade. RESULTS: The results showed that polyacrylate silver salt oral gel had better effect for relieving the oral mucositis. There were statistically significant differences in OM grades (1.59 vs. 2.8, p < 0.0001) between the test group and the control group. CONCLUSION: Our clinical studies demonstrated that polyacrylate silver salt oral gel is an effective interventional option in terms of rapid mucositis healing.

Comparison of periodontal health of primary teeth restored with zirconia and stainless steel crowns: A systemic review and meta-analysis.

BACKGROUND/PURPOSE: In children, the use of stainless steel crowns to treat caries has a high success rate. However, due to the unnatural color of stainless steel crowns, it still needs to modify crown types. The present meta-analysis study aims to explore the previous articles on the comparison of stainless steel crowns and zirconia crowns. METHODS: The systematic search of studies on the comparison of zirconia crowns and stainless steel crowns for primary teeth was mainly in PubMed and Cochrane database. The standardized mean differences (SMDs) of gingival health between zirconia crowns and stainless steel crowns comprised the primary outcome, and the SMDs of plaque index compared two crown treatments was treated as the secondary outcome. RESULTS: The meta-analysis extracted 187 papers from various databases and collected five randomized controlled trials, four comparisons on deciduous molars and one comparison on deciduous incisors. 160 children were included, ranging in age from 3-9 years old. The quantitative analysis showed a significantly lower gingival index of zirconia crowns in the primary molar group and the primary incisor group. The plaque index between two crown treatments groups was -4.51, indicating less accumulation of plaque on zirconia crown. However, the heterogeneity of included trials still need to be considered. CONCLUSION: Zirconia crowns for deciduous teeth had its advantages for gingival health. Although stainless steel crowns were more likely to have plaque deposition and gingival inflammation, zirconia crowns relatively caused the opposite tooth wearing and chipping. Therefore, the comprehensive consideration is important to choose deciduous tooth crown.

Challenge Tooth Regeneration in Adult Dogs with Dental Pulp Stem Cells on 3D-Printed Hydroxyapatite/Polylactic Acid Scaffolds.

Tooth regeneration is an important issue. The purpose of this study was to explore the feasibility of using adult dental pulp stem cells on polylactic acid scaffolds for tooth regeneration. Three teeth were extracted from each side of the lower jaws of two adult dogs. In the experimental group, dental pulp stem cells were isolated and seeded in the 3D-printed hydroxyapatite/polylactic acid (HA/PLA) scaffolds for transplantation into left lower jaw of each dog. The right-side jaw of each dog was transplanted with cell-free scaffolds as the control group. Polychrome sequentially labeling was performed for observation of mineralization. Dental cone beam computed tomography (CBCT) irradiation was used for assessment. Nine months after surgery, dogs were euthanized, and the lower jaws of dogs were sectioned and fixed for histological observation with hematoxylin and eosin staining. The results showed that the degree of mineralization in the experimental group with cells seeded in the scaffolds was significantly higher than that of the control group transplanted with cell-free scaffolds. However, the HA/PLA scaffolds were not completely absorbed in both groups. It is concluded that dental pulp stem cells are important for the mineralization of tooth regeneration. A more rapid absorbable material was required for scaffold design for tooth regeneration.

The Role of Alcohol, LPS Toxicity, and ALDH2 in Dental Bony Defects.

It is estimated that 560 million people carry an East Asian-specific ALDH2*2 dominant-negative mutation which leads to enzyme inactivation. This common ALDH2 polymorphism has a significant association with osteoporosis. We hypothesized that the ALDH2*2 mutation in conjunction with periodontal Porphyromonas gingivalis bacterial infection and alcohol drinking had an inhibitory effect on osteoblasts and bone regeneration. We examined the prospective association of ALDH2 activity with the proliferation and mineralization potential of human osteoblasts in vitro. The ALDH2 knockdown experiments showed that the ALDH2 knockdown osteoblasts lost their proliferation and mineralization capability. To mimic dental bacterial infection, we compared the dental bony defects in wild-type mice and ALDH2*2 knockin mice after injection with purified lipopolysaccharides (LPS), derived from P. gingivalis which is a bacterial species known to cause periodontitis. Micro-computed tomography (micro-CT) scan results indicated that bone regeneration was significantly affected in the ALDH2*2 knockin mice with about 20% more dental bony defects after LPS injection than the wild-type mice. Moreover, the ALDH2*2 knockin mutant mice had decreased osteoblast growth and more dental bone loss in the upper left jaw region after LPS injection. In conclusion, these results indicated that the ALDH2*2 mutation with alcohol drinking and chronic exposure to dental bacterial-derived toxin increased the risk of dental bone loss.

Preclinical evaluation of a 3D-printed hydroxyapatite/poly(lactic-co-glycolic acid) scaffold for ridge augmentation.

BACKGROUND/PURPOSE: Supracrestal ridge augmentation (SRA) is a major challenge for clinicians. This study investigated the efficacy of a 3D-printed (3DP) hydroxyapatite/poly(lactic-co-glycolic acid) (HA/PLGA) scaffold as a potential biologic for SRA. METHODS: Scaffolds that were 5 mm in diameter and 2.5-mm thick with a 1.2-mm diameter through-and-through central hole composed of 90% HA and 10% PLGA were printed using an extrusion-based bioprinter. The HA/PLGA scaffold was fixed with a 1.2-mm titanium mini-implant on the buccal surface of rat mandible (Ti-HPS), and the outcome of SRA were compared with sites treated with a titanium mini-implant alone (control) and a titanium mini-implant covered with deproteinized bovine bone-derived matrix (Ti-DBBM) at 4 and 8 weeks by microcomputed tomography (micro-CT), back-scattered SEM, and histology assessments. RESULTS: The HA/PLGA scaffolds were 2.486 ± 0.082 mm thick with an outer diameter of 4.543 ± 0.057 mm and an inner diameter of 1.089 ± 0.045 mm, and the pore dimensions were 0.48-0.52 mm. There was significantly more mineralized tissue in the Ti-DBBM and Ti-HPS groups than in the control group at both time points. Newly formed bone (NB) was well-integrated with the DBBM and HA/PLGA scaffolds. The framework of the 3DP-HA/PLGA scaffold remained in place, and NB-implant contact (NBIC) was advanced to the middle level in the Ti-HPS group until 8 weeks, whereas dispersion of DBBM with a lower level NBIC was noted in the Ti-DBBM group at both time points. CONCLUSION: The 3DP HA/PLGA scaffold maintains supracrestal space and demonstrates osteoconductivity to facilitate SRA.

Regeneration of critical-sized mandibular defect using a 3D-printed hydroxyapatite-based scaffold: An exploratory study.

BACKGROUND: Three-dimensional (3D) printing has become an available technology to fabricate customized tissue engineering scaffolds with delicate architecture. This exploratory study aimed to evaluate the potential of a 3D-printed hydroxyapatite-based scaffold as a biomaterial for obtaining guided bone regeneration (GBR) in vivo. METHODS: Scaffolds composed of 90% hydroxyapatite and 10% poly(lactic-co-glycolic acid) were printed using a microextrusion process to fit 4 mm diameter and 0.5 mm thick through-and-through osseous defects on the mandibular ramus of rats, with unfilled defects serving as controls. Specimens were analyzed for regeneration-associated gene expression on day 7, and micro-computed tomography (micro-CT) and histology assessments were carried out on day 28. RESULTS: The scaffolds were 3.56 ± 0.43 mm (x-axis) and 4.02 ± 0.44 mm (y-axis) in diameter and 0.542 ± 0.035 mm thick (z-axis), with a mean pore size of 0.420 ± 0.028 × 0.328 ± 0.005 mm2 . Most scaffolds fit the defects well. Type I collagen, VEGF, and Cbfa1 were upregulated in the scaffold-treated defects by day 7. By day 28, de novo osteogenesis and scaffold-tissue integration were evident in the scaffold-treated defects, and entire mineralized tissue, as well as newly formed bone, was significantly promoted, as seen in the micro-CT and histologic analyses. CONCLUSION: The 3D-printed hydroxyapatite-based scaffold showed acceptable dimensional stability and demonstrated favorable osteoregenerative capability that fulfilled the need for GBR.

Perceived pain for orthodontic patients with conventional brackets or self-ligating brackets over 1 month period: A single-center, randomized controlled clinical trial.

BACKGROUND/PURPOSE: The objective of this 2-arm parallel trial was to test the superiority of self-ligating brackets (SLB) over conventional brackets (CB) in terms of perceived pain for orthodontic patients. METHODS: Patients about to undergo treatment were included to fixed appliance placed with CB or SLB. Eligibility criteria included malocclusion patients whose age between 12 to 40 years and suitable for orthodontic fixed appliance treatment. The main outcome was pain intensity measured by visual analog scale (VAS) with all patients followed at 4 h, 24 h, 3 days, 1 week and 1 month. Randomization was accomplished with a computer-generated list of random numbers. Blinding was applicable for outcome assessment only. Data were analyzed using multi-level nonlinear mixed effect model, Friedman's test and Wilcoxon signed rank test with the Bonferroni correction for multiple tests. RESULTS: Eight-eight patients were randomized in a 1:1 ratio to either SLB or CB. All patients completed the study, and none were lost to follow-up. There were no drop-outs after randomization. Baseline characteristics were similar between groups. The is no statistical significant difference in pain intensity between CB and SLB at 4 h, 24 h, 3 days, 1 week and 1 month. Data were analyzed on an intention-to-treat basis. No serious harm was observed. CONCLUSION: The results of this study indicated no evidence that the pain intensity differs between CB and SLB at 4 h, 24 h, 3 days, 1 week and 1 month.

Characterization of designed directional polylactic acid 3D scaffolds for neural differentiation of human dental pulp stem cells.

BACKGROUND/PURPOSE: In recent years, 3D printing technology has flourished and applied to tissue engineering regeneration. The purpose of this study is to investigate the effects of gap width between struts (GWbS) of three-dimensional-printed polylactic acid scaffolds (3DP-PLASs) on neural differentiation of human dental pulp stem cells (hDPSCs). METHODS: Both the 3DP-PLASs with the GWbS of 150 µm and 200 µm were experimental groups and the 3DP-PLAS without microfilament struts was the control group. Properties of 3DP-PLASs were observed by water contact angles (WCA), atomic force microscope (AFM), and differential scanning calorimeter (DSC). The cell culture of hDPSCs on 3DP-PLASs was performed, and cytotoxicities were measured with Alamar Blue assay. The neural differentiation of hDPSCs on different 3DP-PLASs was compared after neural induction. Expressions of neural markers Nestin, MAP2, beta III tubulin, and GFAP were evaluated with immunocytochemical staining. RESULTS: Our results demonstrated no cytotoxicities among scaffolds, whereas they may differ in crystal sizes and directions resulting from different orders of cooling time, contact surface, and temperature distribution during the building process. In addition, hDPSCs could successfully adhere to 3DP-PLAS modified by alcohol or poly-l-Lysine and demonstrate morphological change and related protein performance. CONCLUSION: We conclude that 3DP-PLASs with 150 µm gaps can induce cellular orientations more easily than those with 200 µm gaps. In addition, 3DP-PLASs seem to improve cell adhesion after being coated with poly-l-lysine or soaked with alcohol.

Far-infrared ray radiation promotes neurite outgrowth of neuron-like PC12 cells through AKT1 signaling.

BACKGROUND/PURPOSE: Far-infrared (FIR) therapy is a safe and noninvasive source for medical applications. Animal study has shown the effects of FIR in promoting nerve repair. However, the cellular mechanism is not well known. Nerve growth factor (NGF) treated neuron-like PC12 cells for neurite outgrowth have been widely employed as the in vitro model for neural regeneration. METHODS: In this study, we tried to evaluate the potential of FIR in promoting neurite outgrowth and related mechanism by using NGF-treated neuron-like PC12 cells as a cellular model. We found that FIR could promote neurites outgrowth of neuron-like PC12 cells at earlier culture period. RESULTS: The neurite outgrowth-enhancing effect of FIR irradiation was more obvious when lower NGF concentration (1 ng/ml and 10 ng/ml) was added into the medium. We also found that FIR had no thermal effects on culture medium. The effects of FIR in promoting neurite outgrowth were dose dependent, and higher power density of FIR provided more effects for improving neurite outgrowth. The mechanism of FIR in promoting neurite outgrowth was through AKT1 pathway. CONCLUSION: The effects of FIR irradiation on promoting neurite outgrowth and neural regeneration of NGF-treated neuron-like PC12 cells are dose dependent and through activation of AKT1 phosphorylation. This study provided important information for understanding the cellular mechanism of FIR in promoting neurite outgrowth and possible neural regeneration for further clinical applications.

Promoting dentinogenesis of DPSCs through inhibiting microRNA-218 by using magnetic nanocarrier delivery.

PURPOSE: The purposes of this study are to explore the roles of microRNA-218 (miR-218) delivered by a newly designed magnetic nanocarrier: GCC-Fe3O4 (GCC-Fe) in dentinogenesis potentials of human dental pulp stem cells (DPSCs). METHODS: Human DPSCs were obtained from impacted wisdom teeth of healthy donors under the permission of National Taiwan University Hospital institutional review board (NTUH IRB). Meanwhile, the transfection efficiency of GCC-Fe was evaluated. After transfecting miR-218 (GFm) and miR-218 inhibitor (GFmi) into DPSCs for 24 h, the dentinogenesis potentials of DPSCs were then evaluated with Alizarin Red S (ARS) staining with or without induction for 1, 4, and 9 days. Possible signaling pathway was further investigated by Western Blotting. RESULTS: We found that the magnetic GCC-Fe3O4 nanocarrier was serum endurable with about 90% transfection efficiency in DPSCs under normal culture condition. Results of ARS staining indicated that miR-218 was negatively regulating dentinogenesis potentials of DPSCs after induction. When the miR-218 inhibitor was delivered, calcium deposits in DPSCs were increased significantly. We also discovered that the effects of miR-218 were further regulated through the MAPK/ERK pathway. CONCLUSION: We identified that miR-218 had a negative regulation role in the dentinogenesis of DPSCs. By inhibiting miR-218, the mineralization potentials of DPSCs were promoted after induction. In addition, we also confirmed that the highly efficient magnetic GCC-Fe3O4 nanocarrier not only was suitable for gene manipulation in biomedical studies, but also ideal for future clinical applications due to its serum endurable property.

Developing a novel cholesterol-based nanocarrier with high transfection efficiency and serum compatibility for gene therapy.

BACKGROUND/PURPOSE: Primary cells are sensitive to culture conditions, which can be more difficult to get efficient transfection. The purpose of this study is to develop a serum-compatible cholesterol-based nanocarrier for delivering therapeutic nucleic acids into cells efficiently for future clinical gene therapy. METHODS: A novel cationic 3-ß-[N-(2-guanidinoethyl)carbamoyl]-cholesterol (GEC-Chol) was mixed with cholesterol and superparamagnetic iron oxide (SPIO) nanoparticles to form GCC-Fe3O4 nanocarrier. Transfection efficiency and cytotoxicity in serum and non-serum conditions were evaluated. Florescent-labeled oligonucleotides (ODNs) were transfected as indicators. Fluorescent microscopy, confocal microscopy, and flow cytometry analysis were used for evaluations. Besides, we also delivered functional antisense c-myc ODNs as surrogates for specific gene manipulation in vitro. RESULTS: Results indicated that GCC-Fe3O4 nanocarrier could have size down to less than 135 nm, which structure was highly stable and consistent over time. It also showed great transfection efficiency and low cytotoxicity in both serum and non-serum conditions. Our results demonstrated that GCC-Fe3O4 nanocarrier had exceeded 90% transfection efficiency, which was much better than common commercialized transfection reagents under same conditions. Such nanocarrier not only worked well in cell lines, but also ideal for gene delivery in primary cells. CONCLUSION: With high transfection efficiency and serum compatibility, this novel biocompatible cholesterol-based nanocarrier provides an ideal platform especially for RNAi-based gene manipulation. It also opens a wide range of biomedical applications for in vivo cell tracking and gene therapeutics for clinical usage.

Restorative and Esthetic Dentistry-A Special Issue of the Dentistry Journal.

Due to the development of dental materials and the esthetic requirements of patients, conservative restoration and esthetic dentistry is becoming more and more important.[...].

Curcumin inhibits TGF-ß1-induced connective tissue growth factor expression through the interruption of Smad2 signaling in human gingival fibroblasts.

BACKGROUND/PURPOSE: Many fibrotic processes are associated with an increased level of transforming growth factor-ß1 (TGF-ß1). TGF-ß1 can increase synthesis of matrix proteins and enhance secretion of protease inhibitors, resulting in matrix accumulation. Connective tissue growth factor (CTGF) is a downstream profibrotic effector of TGF-ß1 and is associated with the fibrosis in several human organs. Curcumin has been applied to reduce matrix accumulation in fibrotic diseases. This study was aimed to evaluate whether curcumin could suppress TGF-ß1-induced CTGF expression and its related signaling pathway involving in this inhibitory action in primary human gingival fibroblasts. METHODS: The differences in CTGF expression among three types of gingival overgrowth and normal gingival tissues were assessed by immunohistochemistry. Gingival fibroblast viability in cultured media with different concentrations of curcumin was studied by MTT assay. The effect of curcumin on TGF-ß1-induced CTGF expression in primary human gingival fibroblasts was examined by immunoblotting. Moreover, the proteins involved in TGF-ß1 signaling pathways including TGF-ß1 receptors and Smad2 were also analyzed by immunoblotting. RESULTS: CTGF was highly expressed in fibroblasts, epithelial cells and some of endothelial cells, smooth muscle cells, and inflammatory cells in phenytoin-induced gingival overgrowth tissues rather than in those of hereditary and inflammatory gingival overgrowth tissues. Moreover, CTGF expression in the epithelial and connective tissue layers was higher in phenytoin-induced gingival overgrowth tissues than in normal gingival tissues. Curcumin was nontoxic and could reduce TGF-ß1-induced CTGF expression by attenuating the phosphorylation and nuclear translocation of Smad2. CONCLUSION: Curcumin can suppress TGF-ß1-induced CTGF expression through the interruption of Smad2 signaling.