Highly educated patients have lower dental compliance during the COVID-19 pandemic: an observational study.

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) is rapidly changed medical habits, and dental clinics have been forced to adapt. This study explored the pandemic-induced changes in patient utilization of dental services to assist practitioners in responding efficiently to similar public crises as references in the future. METHODS: We retrospectively analyzed the correlation between patient profiles and dental visits attendance within 2 months before and during the outbreak. RESULTS: A total of 332 patients, 210 women and 122 men (total number of visits: 1068) were enrolled in this study. A significantly lower attendance rate was noted during the COVID-19 period (70.3%) than prior to the pandemic (83.4%). The rate of return visits for patients with a high education level during the COVID-19 period was significantly reduced from 96.5 to 93.1%. In addition, the number of days between two visits significantly increased during the pandemic. CONCLUSIONS: Our results indicate that, during the pandemic period, the attendance rates of return dental appointments decreased, and the rate of missed appointments for patients with a high educational levels was higher than that of patients with a low educational level. CLINICAL RELEVANCE: Preventive management of these patients who are easy to miss dental appointments may enable more effective use of medical resources.

Fluoroquinolones Suppress TGF-ß and PMA-Induced MMP-9 Production in Cancer Cells: Implications in Repurposing Quinolone Antibiotics for Cancer Treatment.

BACKGROUND: Fluoroquinolones (FQs) are potent antimicrobials with multiple effects on host cells and tissues. Although FQs can attenuate cancer invasion and metastasis, the underlying molecular mechanisms remain unclear. Matrix metalloproteinase-9 (MMP-9) has functional roles in tumor angiogenesis, invasion, and metastasis, and is associated with cancer progression and poor prognosis, suggesting that inhibitors of MMP-9 activity and transcription are prime candidates for cancer therapy. Despite numerous preclinical data supporting the use of MMP-9 inhibitors as anticancer drugs, the few available examples are not therapeutically useful due to low specificity and off-target effects. We examined the effects of FQs on MMP-9 production in cancer cells following transforming growth factor beta (TGF-ß) and phorbol 12-myristate 13-acetate (PMA) stimulation. EXPERIMENTAL APPROACHES: Using confluent cultures of HepG2 and A549 cells, the effects of FQs (ciprofloxacin, levofloxacin, clinafloxacin, gatifloxacin, and enrofloxacin) on TGF-ß and PMA-induced MMP-9 mRNA expression and production were studied in RNA extracts and culture supernatants, respectively. FQs specifically abrogated TGF-ß and PMA-induced MMP-9 levels and activity in a concentration and time-dependent manner, without affecting other MMPs or proteins involved in epithelial-mesenchymal transition. Additionally, FQs inhibited TGF-ß and PMA-induced cell migration via p38 and cyclic AMP signaling pathways. CONCLUSIONS AND IMPLICATIONS: Overall, we demonstrated that FQs inhibit cancer cell migration and invasion by downregulating MMP-9 expression and revealed the cellular mechanisms underlying their potential value in cancer treatment.

Transformation of Biomass DNA into Biodegradable Materials from Gels to Plastics for Reducing Petrochemical Consumption.

Ancient biomass is the main source for petrochemicals including plastics, which are inherently difficult to be degraded, increasingly polluting the earth's ecosystem including our oceans. To reduce the consumption by substituting or even replacing most of the petrochemicals with degradable and renewable materials is inevitable and urgent for a sustainable future. We report here a unique strategy to directly convert biomass DNA, at a large scale and with low cost, to diverse materials including gels, membranes, and plastics without breaking down DNA first into building blocks and without polymer syntheses. With excellent and sometimes unexpected, useful properties, we applied these biomass DNA materials for versatile applications for drug delivery, unusual adhesion, multifunctional composites, patterning, and everyday plastic objects. We also achieved cell-free protein production that had not been possible by petrochemical-based products. We expect our biomass DNA conversion approach to be adaptable to other biomass molecules including biomass proteins. We envision a promising and exciting era coming where biomass may replace petrochemicals for most if not all petro-based products.

Bioresponsive DNA Hydrogels: Beyond the Conventional Stimuli Responsiveness.

Bioresponsive hydrogels can respond to various biological stimuli by a macroscopic change of physical state or by converting biochemical inputs into biological or mechanical outputs. These materials are playing an increasingly important role in a wide variety of applications, especially in the biological and biomedical fields. However, the design and engineering of intriguing bioresponsive materials with adequate biocompatibility and biodegradability have proven to be a great challenge. DNA, on the other hand, possesses many unique and fascinating properties, including its indispensable genetic function, broad biocompatibility, precise molecular recognition capability, tunable multifunctionality, and convenient programmability. Therefore, DNA has provided crucial prerequisites for the exploration of novel bioresponsive hydrogels and has since become an ideal building block for the construction of novel materials. In this Account, we describe our efforts over more than a decade to develop DNA-based materials including bioresponsive hydrogels. These DNA hydrogels were created through either chemical cross-linking or physical entanglement among DNA chains. We further divided them into two categories: pure DNA-based and hybrid DNA-based hydrogels. For the pure DNA-based hydrogels, we developed the first bulk DNA hydrogel entirely from branched DNA by using enzymatic ligation. Certain drugs were encapsulated in such hydrogels in situ and released in a controllable manner under the stimulation of environmental factors such as nucleases and/or changes in ionic strength. Furthermore, we prepared a protein-producing hydrogel (termed a "P-gel") by ligating X-shaped DNA (X-DNA) and linear plasmids. Following the central dogma of molecular biology, this hydrogel responded to enzymes and substrate and converted them into proteins. This was the first example showing that a hydrogel could be employed to produce proteins without the involvement of live cells. This might also be the first attempt to create cell-like hydrogels that will be ultimately bioresponsive. In addition, we also constructed a DNA physical hydrogel via entanglement of DNA chains elongated by a special polymerase: Phi29. This hydrogel (termed a "meta-hydrogel") exhibited a "meta" property: freely reversible change between liquidlike and solidlike states through stimulation by water molecules. Besides these pure DNA-based hydrogels, we also created a hybrid DNA-based hydrogel: a DNA-clay hybrid hydrogel utilizing electrostatic interactions between DNA and clay nanocrystals. We discovered a synergistic responsiveness in biochemical reaction in this hydrogel, suggesting that a DNA-clay hydrogel might be the environment for the origination of life and that DNA and clay might have been coevolving during early evolution. In summary, DNA links the nonbiological world with biological processes by virtue of its bioresponsiveness. We envision that bioresponsive DNA hydrogels will play an irreplaceable part in the development of future evolvable materials such as soft robots and artificial cells.

Selective cytotoxic effects of low-power laser irradiation on human oral cancer cells.

BACKGROUND AND OBJECTIVES: Low-power laser irradiation (LPLI) is known to regulate cell proliferation and migration in clinical use. Recent studies have shown that LPLI induces cell death in some certain types of cancer cell lines. However, the cytotoxic selectivity of LPLI for cancer cells is not fully understood. The aim of this study was to compare the cytotoxic effects of LPLI in both human oral cancer OC2 cells and normal human gingival fibroblast (HGF) cells. MATERIALS AND METHODS: LPLI at 810 nm with an energy density from 10 to 60 J/cm(2) was used to irradiate human oral cancer OC2 cells and normal HGF cells. RESULTS: We found that LPLI significantly diminished cell viability of human oral cancer OC2 cells due to cell cycle arrest at the G1 phase and the induction of cell death but that it had no or little effects on cell cycle progression and death in normal HGF cells. Moreover, the production of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential (MMP) were elevated in human oral cancer OC2 cells compared with the un-irradiated cells. In contrast, these effects remained unchanged in normal HGF cells after exposure to LPLI. LPLI also induced apoptosis in caspase-3 dependent manner in human oral cancer OC2 cells, a mode of action that could be mediated by ROS and mitochondrial damage. CONCLUSION: Our findings imply LPLI might be a potential therapy for oral cancers.

Pluronic-poly[alpha-(4-aminobutyl)-1-glycolic acid] polymeric micelle-like nanoparticles as carrier for drug delivery.

Pluronic-poly[alpha-(4-aminobutyl)-1-glycolic acid] (Pluronic-PAGA) with different types of Pluronic, the different molecule weight of PAGA, and the different molar ratios of Pluronic to PAGA were synthesized. These materials were bio-degradable, amphiphilic, could be degraded into non-toxic small molecules and could be used to carry drugs. 5-Fluorouracil (5-Fu) loaded Pluronic-PAGA micelle-like nanoparticles (5-Fu loaded P-PAGA NPs) were prepared by a simple self-assembly method, and characterized by dynamic light scattering, transmission electron microscope. The degradation and release characteristics have also been studied in this paper. With the time passing, the 5-Fu loaded P-PAGA NPs degraded into smaller ones with the similar characteristics of the original NPs. Both the types of Pluronic and the molecule weight of the PAGA affected the releasing progresses. It was found that 5-Fu loaded P-PAGA NPs exhibited high growth inhibitory effect on human gastric cancer cells by MTT assay. The cellular uptake of Rhodamine B loaded P-PAGA NPs was higher than free Rhodamine B. This study suggested that the Pluronic-PAGA with acceptable drug entrapment efficiencies, drug loading efficiencies and tunable release profiles could offer an alternative carrier for 5-Fu delivery and have the potential for the delivery of other anti-tumour drug.

Association between prosthesis contour and peri-implantitis in patients compliant with supportive periodontal therapy: A retrospective cohort study.

PURPOSE: Poor contour of the implant restoration causes plaque accumulation and increases the risk of peri-implantitis. This study aimed to investigate whether the prosthodontic components of dental implants were associated with the prevalence of peri-implantitis. METHODS: We enrolled 185 patients with 348 implants who underwent at least 1-year follow-up after the delivery of the prosthesis from February 2010 to January 2021. Demographic data of the patients and implants and the follow-up period were recorded. The emergence angle, type of cervical crown contour, and contour angle were analyzed using annual bite-wing radiographs. Peri-implantitis in this study was diagnosed if the peri-implant bone loss was greater than 2 mm between the bite-wing radiographs taken at baseline and the latest. Chi-square test, two-sample t-test, and multivariate logistic regression were used to investigate the differences and odds ratios between the peri-implantitis and non-peri-implantitis groups. RESULTS: The incidence of peri-implantitis was 14.9% during a follow-up period of 1509 days after the delivery of the prosthesis for at least 1-year. Based on the prevalence of non-peri-implantitis and after adjusting for confounding factors, the risk factors identified were bone types for implants (native bone vs. alveolar ridge preservation: adjusted odds ratio = 2.43, P = 0.04). Sex, arch, and guided bone regeneration vs. alveolar ridge preservation have the potential for a statistical difference. CONCLUSIONS: Compared with implants at alveolar ridge preservation sites, implants in the native bone were more prone to peri-implantitis. Further randomized controlled trials are required to determine these associations.

The use of customized 3D-printed mandibular prostheses with pressure-reducing device: A clinical trial.

BACKGROUND: Segmental bone defects of the mandible result in the complete loss of the affected region. We had incorporated the pressure-reducing device (PRD) designs into the customized mandible prostheses (CMP) and conducted a clinical trial to evaluate this approach. METHODS: Seven patients were enrolled in this study. We examined the association among the history of radiotherapy, the number of CMP regions, the number of chin regions involved, and CMP exposure. RESULTS: We included five men and two women with an average age of 55 years. We excised tumors with an average weight of 147.8 g and the average weight of the CMP was 68.5 g. No significant difference between the two weights was noted (p = 0.3882). Three patients received temporary dentures and the CMP remained stable in all patients. CONCLUSION: The use of PRD in CMP may address the previous challenges associated with CMP, but further research is necessary.

Use of customized 3-dimensional printed mandibular prostheses with a dental implant pressure-reducing device in mandibular body defect: A finite element study performing multiresponse surface methodology.

Background/purpose: Segmental body defects of the mandible result in the complete loss of the affected region. In our previous study, we investigated the clinical applicability of a customized mandible prosthesis (CMP) with a pressure-reducing device (PRD) in an animal study. In this study, we further incorporated dental implants into the CMP and explored the use of dental implant PRD (iPRD) designs. Materials and methods: By employing a finite element analysis approach, we created 4 types of CMP: CMP, CMP with iPRD, CMP-PRD, and CMP-PRD with iPRD. We developed 2 parameters for the iPRD: cone length (CL) in the upper part and spring pitch (SP) in the lower part. Using the response surface methodology (RSM), we determined the most suitable structural assignment for the iPRD. Results: Our results indicate that CMP-PRD had the highest von Mises stress value for the entire assembly (1076.26 MPa). For retentive screws and abutments, CMP with iPRD had the highest von Mises stress value (319.97 and 452.78 MPa, respectively). CMP-PRD had the highest principal stress (131.66 MPa) in the anterior mandible. The iPRD reduced principal stress in both the anterior and posterior mandible. Using the RSM, we generated 25 groups for comparison to achieve the most favorable results for the iPRD and we might suggest the CL to 12 mm and the SP to 0.4 mm in the further clinical trials. Conclusion: Use of the PRD and iPRD in CMP may resolve the challenges associated with CMP, thereby promoting its usage in clinical practice.

Antitumor efficacy of paclitaxel-loaded polylactide/ poly(ethylene glycol) nanoparticles combination with exercise in tumor-bearing mice.

The nanoparticles (NPs) provide a promising prospect for tumor therapy, and exercise is also becoming readily and accepted as a beneficial adjunct therapy to maintain or enhance quality of life in cancer patients. We investigate the antitumor efficacy of paclitaxel (PT) loaded polylactide/poly(ethylene glycol) NPs (PT-PLA/PEG NPs) under the exercise conditions. Results showed that within the first 7 days, the PT concentration in tumor maintained at a higher level in the PT-PLA/PEG NPs + exercise (PT-PLA/PEG NPs + EX) group as compared with the PT-PLA/PEG NPs group. All the phagocytosis rates of macrophages were significantly decreased below the CON in exercise group. The most significant antitumor effect was observed in PT-PLA/PEG NPs + EX group, demonstrating that the PT-PLA/PEG NPs improved the concentration of PT, and exercise could further increased its therapeutic efficiency for tumor. These researches may provide an effective means for tumor therapy.

Changes in alveolar bone width around maxillary implants, as determined through cone beam computed tomography based on bony landmarks: A preliminary study.

PURPOSE: This study aimed to investigate changes in alveolar bone width around dental implants and identify the anterior nasal spine (ANS), posterior nasal spine (PNS), and floor of the nasal cavity that can be used as reference landmarks for standardizing the orientation of different cone-beam computed tomography (CBCT) scans. MATERIALS AND METHODS: We enrolled two groups that comprised 30 implants. Two CBCT scans from the same patient after implant surgery in the first group were obtained to determine differences in the relative distance and angle between the ANS and apex of the dental implant. Then we compared the second group of patients' presurgical and postsurgical CBCT images to evaluate changes in alveolar bone width after dental implant surgery by the aforementioned bony landmarks. RESULTS: In the first group, no statistically significant differences were detected in the mean distance between the ANS, PNS and implant tip in different directions. In the second group, bone width increased at 1 mm (p = 0.020) and decreased at 4 mm (p < 0.001) and 7 mm (p < 0.001) below the alveolar bone crest after implant surgery. CONCLUSIONS: Within the limitations of the present study, the ANS, PNS, and floor of the nasal cavity can be useful in standardizing the orientation of CBCT scans and alveolar bone remodeling after implant surgery varied depending on the height and direction from the alveolar bone crest based on the three landmarks.

Prevalence of peri-implantitis after alveolar ridge preservation at periodontitis and nonperiodontitis extraction sites: A retrospective cohort study.

INTRODUCTION: Periodontitis is the main indication for dental extraction and often leads to peri-implantitis (PI). Alveolar ridge preservation (ARP) is an effective means of preserving ridge dimensions after extraction. However, whether PI prevalence is lower after ARP for extraction after periodontitis remains unclear. This study investigated PI after ARP in patients with periodontitis. MATERIALS AND METHODS: This study explored the 138 dental implants of 113 patients. The reasons for extraction were categorized as periodontitis or nonperiodontitis. All implants were placed at sites treated using ARP. PI was diagnosed on the basis of radiographic bone loss of ≥3 mm, as determined through comparison of standardized bitewing radiographs obtained immediately after insertion with those obtained after at least 6 months. Chi-square and two-sample t testing and generalized estimating equations (GEE) logistic regression model were employed to identify risk factors for PI. Statistical significance was indicated by p < 0.05. RESULTS: The overall PI prevalence was 24.6% (n = 34). The GEE univariate logistic regression demonstrated that implant sites and implant types were significantly associated with PI (premolar vs. molar: crude odds ratios [OR] = 5.27, 95% confidence intervals [CI] = 2.15-12.87, p = 0.0003; bone level vs. tissue level: crude OR = 5.08, 95% CI = 2.10-12.24; p = 0.003, respectively). After adjustment for confounding factors, the risks of PI were significantly associated with implant sites (premolar vs. molar: adjusted OR [AOR] = 4.62, 95% CI = 1.74-12.24; p = 0.002) and implant types (bone level vs. tissue level: AOR = 6.46, 95% CI = 1.67-25.02; p = 0.007). The reason for dental extraction-that is, periodontitis or nonperiodontitis-was not significantly associated with PI. CONCLUSION: ARP reduces the incidence of periodontitis-related PI at extraction sites. To address the limitations of our study, consistent and prospective randomized controlled trials are warranted.

cRGD conjugated mPEG-PLGA-PLL nanoparticles for SGC-7901 gastric cancer cells-targeted Delivery of fluorouracil.

The main purpose of this study was to evaluate the targeting effect of cyclic arginine-glycine-aspartic peptide (cRGD)-modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly (L-lysine) nanoparticles (mPEG-PLGA-PLL-cRGD NPs) for gastric cancer SGC-7901 cells. We prepared the 5-Fulorouracil (5Fu)-loaded mPEG-PLGA-PLL-cRGD (5Fu/mPEG-PLGA-PLL-cRGD) NPs that had an average particle size of 180 nm and a zeta potential 2.77 mV. The results of cytotoxicity demonstrated the mPEG-PLGA-PLL-cRGD NPs showed the ignorable cytotoxicity and the 5Fu/mPEG-PLGA-PLL-cRGD NPs could significantly enhance the cytotoxicity of 5Fu. In vitro drug release experiments showed that the release of drug was effectively prolonged and sustained. The results of confocal laser scanning microscope (CLSM) and flow cytometer analysis demonstrated that the fluorescence intensity of the SGC-7901 gastric cancer cells treated with Rb/mPEG-PLGA-PLL-cRGD NPs was significantly higher than that treated with Rb, this suggested that Rb/mPEG-PLGA-PLL-cRGD NPs could effectively be internalized by SGC-7901 gastric cancer cells. In summary, the above experimental results illustrate that mPEG-PLGA-PLL-cRGD NPs have great potential to be used as an effective delivery carriers.

Biodegradable nanoparticles of mPEG-PLGA-PLL triblock copolymers as novel non-viral vectors for improving siRNA delivery and gene silencing.

Degradation of mRNA by RNA interference is one of the most powerful and specific mechanisms for gene silencing. However, insufficient cellular uptake and poor stability have limited its usefulness. Here, we report efficient delivery of siRNA via the use of biodegradable nanoparticles (NPs) made from monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly-l-lysine (mPEG-PLGA-PLL) triblock copolymers. Various physicochemical properties of mPEG-PLGA-PLL NPs, including morphology, size, surface charge, siRNA encapsulation efficiency, and in vitro release profile of siRNA from NPs, were characterized by scanning electron microscope, particle size and zeta potential analyzer, and high performance liquid chromatography. The levels of siRNA uptake and targeted gene inhibition were detected in human lung cancer SPC-A1-GFP cells stably expressing green fluorescent protein. Examination of the cultured SPC-A1-GFP cells with fluorescent microscope and flow cytometry showed NPs loading Cy3-labeled siRNA had much higher intracellular siRNA delivery efficiencies than siRNA alone and Lipofectamine-siRNA complexes. The gene silencing efficiency of mPEG-PLGA-PLL NPs was higher than that of commercially available transfecting agent Lipofectamine while showing no cytotoxicity. Thus, the current study demonstrates that biodegradable NPs of mPEG-PLGA-PLL triblock copolymers can be potentially applied as novel non-viral vectors for improving siRNA delivery and gene silencing.

RGD-conjugated PLA-PLL nanoparticles targeting to Bacp-37 breast cancer xenografts in vivo.

Targeted delivery carriers are receiving considerable attention, the development of a more precise targeted delivery carrier is critical for the advancement of cancer chemotherapy. In this study, we evaluated the effects of RGD-conjugated poly (lactic acid-co-lysine)-(Arginine-Glycine-Aspartic) nanoparticles (PLA-PLL-RGD NPs) on targeted delivery to Bacp-37 breast cancer bearing mice. PLA-PLL-RGD NPs were prepared by using the emulsion-solvent evaporation method. A subsequent MTT assay indicated that the NPs were non-toxic and had good biocompatibility. In vitro, the results of Confocal Laser Scanning Microscope (CLSM) and FAC Scan flow cytometry (FACS) indicated that the PLA-PLL-RGD NPs can bind more significantly to human umbilical vein endothelial cells, compared to PLA-PLL NPs. In vivo, the results of target imaging and biodistribution showed that PLA-PLL-RGD can significantly target to tumor of Bacp-37 breast cancer bearing mice. These results demonstrated that PLA-PLL-RGD NPs can effectively enhance targeted efficiency in vivo, and have the potential to be used as targeted delivery carrier.

Microfluidic-directed biomimetic Bulbine torta-like microfibers based on inhomogeneous viscosity rope-coil effect.

Helical structures are attracting increasing attention owing to their unique typical physical and chemical properties. However, it remains a challenge to construct atypical helical structures at the microscale. This paper proposes a continuous spinning method with a microfluidic-chip-based spinning device to engineer atypical helical microfibers. The strategy causes polymer fluid to form the biomimetic Bulbine torta (BT)-like shape with the aid of the inhomogeneous viscosity rope-coil effect. In particular, the structure parameter of the BT microfibers could be optimized through the synchronous regulation of the microfluidic flow and reaction kinetics, and the obtained microfibers exhibit ultrahigh strain sensitivity, indicating great promise as exceptional candidates for constructing ideal strain sensors. In addition, single- and double-hollow BT microfibers are also prepared by introducing the core flow channel into the microfluidic chip and demonstrate high structural similarity to irregular blood vessels (e.g. varicose veins), which is promising for the actual application of blood vessel tissue engineering.

Nanoassemblies with Effective Serum Tolerance Capability Achieving Robust Gene Silencing Efficacy for Breast Cancer Gene Therapy.

The transfection efficiency of siRNA mediated by cationic polymers is limited due to the instability of polymers/siRNA complexes in the presence of serum. Poly(ethylene glycol) (PEG) is usually applied to modify cationic polymers, so as to reduce protein and cell adsorption and then to improve siRNA transfection efficiency. However, the polymers' modification with PEG mostly consumes the free amino of the polymers, which can, in turn, reduce the charge density and limit their siRNA transfection efficacy. Here, a new PEG modification strategy that need not consume the surface aminos of polymers is proposed. Catechol-PEG polymers are coated on the surface of phenylboronic acid (PBA)-modified Generation 5 (G5) poly(amidoamine) dendrimers (G5PBA) via reversible boronate esters to establish PEG-modified dendrimer/siRNA nanoassemblies for efficient siRNA delivery. The PEG/G5PBA/siRNA nanoassemblies have positive charge and show excellent gene silencing efficacy in the absence of serum in vitro. More importantly, the PEG/G5PBA/siRNA nanoassemblies also exhibit excellent serum resistance and gene silencing efficacy in serum-containing medium. Furthermore, the effective antiserum and gene silencing efficacy elicited by these nanoassemblies lead to excellent antitumor effects in vivo. This proposed strategy constitutes an important approach to reach an excellent gene silencing efficacy in the presence of serum.

Using Cone-Beam Computed Tomography to Assess Changes in Alveolar Bone Width around Dental Implants at Native and Reconstructed Bone Sites: A Retrospective Cohort Study.

The aim of this study was to use a cone-beam computed tomography (CBCT) to assess changes in alveolar bone width around dental implants at native and reconstructed bone sites before and after implant surgery. A total of 99 implant sites from 54 patients with at least two CBCT scans before and after implant surgery during 2010-2019 were assessed in this study. Demographic data, dental treatments and CBCT scans were collected. Horizontal alveolar bone widths around implants at three levels (subcrestal width 1 mm (CW1), subcrestal width 4 mm (CW4), and subcrestal width 7 mm (CW7)) were measured. A p-value of < 0.05 indicated statistically significant differences. The initial bone widths (mean ± standard deviation (SD)) at CW1, CW4, and CW7 were 6.98 ± 2.24, 9.97 ± 2.64, and 11.33 ± 3.00 mm, respectively, and the postsurgery widths were 6.83 ± 2.02, 9.58 ± 2.55, and 11.19 ± 2.90 mm, respectively. The change in bone width was 0.15 ± 1.74 mm at CW1, 0.39 ± 1.12 mm at CW4 (p = 0.0008), and 0.14 ± 1.05 mm at CW7. A statistically significant change in bone width was observed at only the CW4 level. Compared with those at the native bone sites, the changes in bone width around implants at reconstructed sites did not differ significantly. A significant alveolar bone width resorption was found only at the middle third on CBCT scans. No significant changes in bone width around implants were detected between native and reconstructed bone sites.

The essentiality of alpha-2-macroglobulin in human salivary innate immunity against new H1N1 swine origin influenza A virus.

A novel strain of influenza A H1N1 emerged in the spring of 2009 and has spread rapidly throughout the world. Although vaccines have recently been developed that are expected to be protective, their availability was delayed until well into the influenza season. Although anti-influenza drugs such as neuraminidase inhibitors can be effective, resistance to these drugs has already been reported. Although human saliva was known to inhibit viral infection and may thus prevent viral transmission, the components responsible for this activity on influenza virus, in particular, influenza A swine origin influenza A virus (S-OIV), have not yet been defined. By using a proteomic approach in conjunction with beads that bind alpha-2,6-sialylated glycoprotein, we determined that an alpha-2-macroglobulin (A2M) and an A2M-like protein are essential components in salivary innate immunity against hemagglutination mediated by a clinical isolate of S-OIV (San Diego/01/09 S-OIV). A model of an A2M-based "double-edged sword" on competition of alpha-2,6-sialylated glycoprotein receptors and inactivation of host proteases is proposed. We emphasize that endogenous A2M in human innate immunity functions as a natural inhibitor against S-OIV.

Microstructure, mechanical properties, degradation behavior, and biocompatibility of porous Fe-Mn alloys fabricated by sponge impregnation and sintering techniques.

In this study, porous iron (Fe)-manganese (Mn) alloys with high porosity were successfully prepared by sponge impregnation and sintering (SIS). The compositions of the porous Fe-Mn alloys were strongly dependent on the sintering temperature, and the Mn content was ~44, 30, and 12 wt.% for alloys sintered at 1100, 1150, and 1200 °C, respectively. The porous Fe-Mn alloys exhibited a well-interconnected porous structure with ~85% porosity and average pore size ranging from 375 to 500 um. The porous Fe-44Mn and Fe-30Mn alloys were mainly composed of a γ-austenite phase, while the porous Fe-12Mn was composed of an α-ferrite phase. The yield strength and elastic modulus of the porous Fe-Mn alloys ranged from 6 to 10 MPa and from 0.12 to 0.37 GPa, respectively, similar to those of cancellous bone. The degradation rate of the porous Fe-Mn alloys decreased over time during immersion in simulated body fluid (SBF), and was 1.0 mm/year for Fe-44Mn, 0.81 mm/year for Fe-30Mn, 0.41 mm/year for Fe-12Mn, and 0.33 mm/year for pure Fe after 14 d SBF immersion. Moreover, the porous Fe-Mn alloys exhibited good biocompatibility with clearly enhanced cell proliferation after direct culturing of osteoblastic MC3T3-E1 cells for 7 d. Thus, these porous Fe-Mn alloys can be anticipated to be promising biodegradable implant materials. STATEMENT OF SIGNIFICANCE: This work reports on porous Fe-Mn alloys with high porosity, suitable mechanical properties and degradation rate, and good biocompatibility. The porous alloys prepared by sponge impregnation and sintering exhibited a well-interconnected porous structure with ~85% porosity and average pore size ranging from 375 to 500 um. The yield strength and elastic modulus of the porous alloys ranged from 6 to 10 MPa and from 0.12 to 0.37 GPa, respectively, similar to those of cancellous bone. The degradation rates in simulated body fluid (SBF) were ~1.0 mm/year for Fe-44Mn, 0.81 mm/year for Fe-30Mn, and 0.41 mm/year for Fe-12Mn, respectively. Moreover, the porous Fe-Mn alloys exhibited good biocompatibility with enhanced cell proliferation after direct culturing of osteoblastic MC3T3-E1 cells.