The influence of Ni(II) on surface antigen expression in murine macrophages

T1-weighted MRI of targeting atherosclerotic plaque based on CD40 expression on engulfed USPIO's cell surface

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of cholesterol within the arterial wall. Its progression can be monitored via magnetic resonance imaging (MRI). Ultrasmall Superparamagnetic Particles of Iron Oxide (USPIO) (<5 nm) have been employed as T1 contrast agents for MRI applications. In this study, we synthesized USPIO with an average surface carboxylation of approximately 5.28 nm and a zeta potential of -47.8 mV. These particles were phagocytosed by mouse aortic endothelial cells (USPIO-MAECs) and endothelial progenitor cells (USPIO-EPCs), suggesting that they can be utilized as potential contrast agent and delivery vehicle for the early detection of atherosclerosis. However, the mechanism by which this contrast agent is delivered to the plaque remains undetermined. Our results demonstrated that with increasing USPIO concentration during 10-100 μg ml-1, consistent change appeared in signal enhancement on T1-weighted MRI. Similarly, T1-weighted MRI of MAECs and EPCs treated with these concentrations exhibited a regular change in signal enhancement. Prussian blue staining of USPIO revealed substantial absorption into MAECs and EPCs after treatment with 50 μg ml-1USPIO for 24 h. The iron content in USPIO-EPCs was much higher (5 pg Fe/cell) than in USPIO-MAECs (0.8 pg Fe/cell). In order to substantiate our hypothesis that CD40 protein on the cell surface facilitates migration towards inflammatory cells, we utilized AuNPs-PEI (gold nanoparticles-polyethylenimine) carrying siRNACD40to knockout CD40 expression in MAECs. It has been documented that gold nanoparticle-oligonucleotide complexes could be employed as intracellular gene regulation agents for the control of protein level in cells. Our results confirmed that macrophages are more likely to bind to MAECs treated with AuNPs-PEI-siRNANC(control) for 72 h than to MAECs treated with AuNPs-PEI-siRNACD40(reduced CD40 expression), thus confirming CD40 targeting at the cellular level. When USPIO-MAECs and MAECs (control) were delivered to mice (high-fat-fed) via tail vein injection respectively, we observed a higher iron accumulation in plaques on blood vessels in high-fat-fed mice treated with USPIO-MAECs. We also demonstrated that USPIO-EPCs, when delivered to high-fat-fed mice via tail vein injection, could indeed label plaques by generating higher T1-weighted MRI signals 72 h post injection compared to controls (PBS, USPIO and EPCs alone). In conclusion, we synthesized a USPIO suitable for T1-weighted MRI. Our results have confirmed separately at the cellular and tissue andin vivolevel, that USPIO-MAECs or USPIO-EPCs are more accessible to atherosclerotic plaques in a mouse model. Furthermore, the high expression of CD40 on the cell surface is a key factor for targeting and USPIO-EPCs may have potential therapeutic effects.

Molecular basis and therapeutic implications of CD40/CD40L immune checkpoint

The CD40 receptor and its ligand CD40L is one of the most critical molecular pairs of the stimulatory immune checkpoints. Both CD40 and CD40L have a membrane form and a soluble form generated by proteolytic cleavage or alternative splicing. CD40 and CD40L are widely expressed in various types of cells, among which B cells and myeloid cells constitutively express high levels of CD40, and T cells and platelets express high levels of CD40L upon activation. CD40L self-assembles into functional trimers which induce CD40 trimerization and downstream signaling. The canonical CD40/CD40L signaling is mediated by recruitment of TRAFs and NF-κB activation, which is supplemented by signal pathways such as PI3K/AKT, MAPKs and JAK3/STATs. CD40/CD40L immune checkpoint leads to activation of both innate and adaptive immune cells via two-way signaling. CD40/CD40L interaction also participates in regulating thrombosis, tissue inflammation, hematopoiesis and tumor cell fate. Because of its essential role in immune activation, CD40/CD40L interaction has been regarded as an attractive immunotherapy target. In recent years, significant advance has been made in CD40/CD40L-targeted therapy. Various types of agents, including agonistic/antagonistic monoclonal antibodies, cellular vaccines, adenoviral vectors and protein antagonist, have been developed and evaluated in early-stage clinical trials for treating malignancies, autoimmune diseases and allograft rejection. In general, these agents have demonstrated favorable safety and some of them show promising clinical efficacy. The mechanisms of benefits include immune cell activation and tumor cell lysis/apoptosis in malignancies, or immune cell inactivation in autoimmune diseases and allograft rejection. This review provides a comprehensive overview of the structure, processing, cellular expression pattern, signaling and effector function of CD40/CD40L checkpoint molecules. In addition, we summarize the progress, targeted diseases and outcomes of current ongoing and completed clinical trials of CD40/CD40L-targeted therapy.

Biological and Chemo-Physical Features of Denture Resins

In the dental field, the study of materials has always been the basis of the clinical practice. Over the years, with the evolution of materials, it has been possible to produce safe and predictable prosthetic devices, with ever better aesthetic features, biocompatibility and patient satisfaction. This review briefly analyzes the features of dental resin materials to underline the biological, microbiological and chemo-physical characteristics. The main aim of prosthodontics is to rehabilitate patients and therefore improve their quality of life. Dental resins are the main materials used for the production of dentures. Once solidified, these polymers have different mechanical or surface characteristics. The results of the literature on these characteristics were analyzed and some new brand dental resins, known as modern resin, were subsequently evaluated. The new materials are undoubtedly a step forward in the creation of dental prostheses, and also in all subsequent maintenance phases. This review shows how changing the chemical structure of the resins could have microbiological influences on the growth and management of the biofilm, and also physical influences in terms of its mechanical characteristics. The development of new materials is a constant goal in dentistry in order to obtain increasingly predictable rehabilitations.

Evaluation of Imaging Software Accuracy for 3-Dimensional Analysis of the Mandibular Condyle. A Comparative Study Using a Surface-to-Surface Matching Technique

The aim of this study was to assess the accuracy of 3D rendering of the mandibular condylar region obtained from different semi-automatic segmentation methodology. A total of 10 Cone beam computed tomography (CBCT) were selected to perform semi-automatic segmentation of the condyles by using three free-source software (Invesalius, version 3.0.0, Centro de Tecnologia da Informação Renato Archer, Campinas, SP, Brazil; ITK-Snap, version2.2.0; Slicer 3D, version 4.10.2) and one commercially available software Dolphin 3D (Dolphin Imaging, version 11.0, Chatsworth, CA, USA). The same models were also manually segmented (Mimics, version 17.01, Materialise, Leuven, Belgium) and set as ground truth. The accuracy of semi-automatic segmentation was evaluated by (1) comparing the volume of each semi-automatic 3D rendered condylar model with that obtained with manual segmentation, (2) deviation analysis of each 3D rendered mandibular models with those obtained from manual segmentation. No significant differences were found in the volumetric dimensions of the condylar models among the tested software (p > 0.05). However, the color-coded map showed underestimation of the condylar models obtained with ITK-Snap and Slicer 3D, and overestimation with Dolphin 3D and Invesalius. Excellent reliability was found for both intra-observer and inter-observer readings. Despite the excellent reliability, the present findings suggest that data of condylar morphology obtained with semi-automatic segmentation should be taken with caution when an accurate definition of condylar boundaries is required.

Cytotoxicity and oxidative stress induced by nickel and titanium ions from dental alloys on cells of gastrointestinal tract

The aim was to explore the biological effect of nickel (Ni) and titanium (Ti) ions released from dental alloys. NiTi alloy were exposed to 40 mL of artificial saliva (pH = 4.8, t = 37 °C). The dynamics of Ni and Ti ions release during corrosion were recorded on the 3th, 7th and 14th day. Biological effect of Ni and Ti ions released from alloy was explored on cell lines of human tongue CAL 27, liver Hep G2 and colon Caco-2. Neutral Red uptake assay for the estimation of cell viability/cytotoxicity and 2',7'-dichlorofluorescein diacetate fluorimetric assay for reactive oxygen species were used. Cells were exposed to the following concentration of corrosion products: 5.0×, 1.0×, 0.5 and 0.1× during the period of 24, 48 and 72 h. To check the effect of each metal separately, cells were exposed to nickel-chloride and titanium-dioxide of corresponding concentration. The release of Ni is higher than of Ti (15.1-30.4 μg/L for Ni and 9.0-17.3 μg/L for Ti, respectively) and 5× higher concentrations are needed to induce cytotoxic effect. Ni and Ti ions alone do not induce a major cytotoxic effect, but their combination does indicating their synergistic effect. Increase in concentration of Ni and Ti tends to increase cytotoxicity, Ti more than Ni. Cytotoxicity and induction of free radicals are in strong positive linear correlation. Ions released from NiTi alloy during 14 days do not induce significant cytotoxic effect and would not have a clinically important impact. Cytotoxic effect is largely the result of the induction of free radicals.

Astragalus Polysaccharide RAP Induces Macrophage Phenotype Polarization to M1 via the Notch Signaling Pathway

Macrophages occur in polarized phenotypes, whose characteristics determine the role they play in tumor growth. The M1 phenotype macrophages promote tumoricidal responses and suppress tumor growth. Our previous study showed that a polysaccharide isolated from Radix Astragali, named RAP, was itself non-cytotoxic but induced RAW264.7 cells' cytotoxicity against cancer cells. The current study was undertaken to determine its mechanism. Series studies was conducted to show that RAP is able to induce much higher gene expression of M1 markers, including iNOS, IL-6, TNF-a, and CXCL10, compared with the control group. When RAP-induced BMDMs were transplanted together with 4T1 tumor cells in BALB/c mice, both tumor volume and tumor weight decreased. Further studies indicated that RAP induces the Notch signaling pathway in RAW264.7 cells. The function of Notch signaling in macrophage polarization was confirmed by using γ-secretase inhibitor. These results suggested that Astragalus polysaccharide RAP induces macrophage's polarization to M1 phenotype via the Notch signaling pathway.

Cytokine Expression and Macrophage Localization in Xenograft and Allograft Tumor Models Stimulated with Lipopolysaccharide

T cell-deficient mice such as nude mice are often used to generate tumor xenograft for the development of anticancer agents. However, the functionality of the other immune cells including macrophages, dendritic cells (DCs), and myeloid-derived suppressor cells (MDSCs) in the xenograft are largely unknown. Macrophages and dendritic cells (DCs) acquire functionally distinct properties in response to various environmental stimuli; the interaction of these cells with MDSCs in tumor microenvironments regulates cancer progression. Nude mice are less likely to reject human cancer cells because of major histocompatibility complex (MHC) mismatches. The tumor microenvironment in a xenograft, comprising human and mouse cells, exhibits more complex bidirectional signaling and function than that of allograft. Here, we evaluated the differences of myeloid cells between them. Plasma interferon-γ and interleukin-18 concentrations in the xenograft tumor model after lipopolysaccharide (LPS) administration were significantly higher than those in the allograft tumor model. MHC class I, II, and CD80 expression levels were increased in CD11b⁺ and MDSC populations after LPS administration in the spleen of a xenograft tumor model but not in that of an allograft tumor model. Additionally, the number of CD80- and mannose receptor C type 1 (MRC1)-expressing cells was decreased upon LPS administration in the tumor of the xenograft tumor. These results suggest that functions of macrophages and DCs are sustained in the xenograft, whereas their functions in response to LPS were suppressed in the allograft. The findings will encourage the consideration of the effects of myeloid cells in the xenograft for drug development.

Effect of bleaching agent extracts on murine macrophages

OBJECTIVES

The aim of this study was to evaluate the cytotoxicity and the influence of bleaching agents on immunologically cell surface antigens of murine macrophages in vitro.

MATERIALS AND METHODS

RAW 264.7 cells were exposed to bleaching gel extracts (40% hydrogen peroxide or 20% carbamide peroxide) and different H₂O₂ concentrations after 1 and 24-h exposure periods and 1-h exposure and 23-h recovery. Tests were performed with and without N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO). Cell viability was determined by MTT assay. The expression of surface markers CD14, CD40, and CD54 with and without LPS stimulation was detected by flow cytometry, while the production of TNF-α was measured by ELISA. Statistical analysis was performed using the Mann-Whitney U test (α = 0.05).

RESULTS

Extracts of bleaching agents were cytotoxic for cells after a 1-h exposure; cells could not recover after 24 h. This effect can be mitigated by the antioxidant NAC and increased by BSO, an inhibitor of glutathione (GSH) synthesis. LPS stimulated expression of all surface markers and TNF-α production. Exposure to bleaching agent extracts and H₂O₂ leads to a reduction of TNF-α, CD14, and CD40 expression, while the expression of CD54 was upregulated at non-cytotoxic concentrations. Whereas NAC reduced this effect, it was increased in the presence of BSO.

CONCLUSIONS

Extracts of bleaching agents were irreversibly cytotoxic to macrophages after a 1-h exposure. Only the expression of CD54 was upregulated. The reactions are mediated by the non-enzymatic antioxidant GSH.

CLINICAL RELEVANCE

The addition of an antioxidant can downregulate unfavorable effects of dental bleaching.

Surface and Protein Adsorption Properties of 316L Stainless Steel Modified with Polycaprolactone Film

The surface and protein adsorption properties of 316L stainless steel (316L SS) modified with polycaprolactone (PCL) films are systematically investigated. The wettability of the PCL films was comparable to that of bare 316L SS because the rough surface morphology of the PCL films counteracts their hydrophobicity. Surface modification with PCL film significantly improves the corrosion resistance of the 316L SS because PCL is insulating in nature. A coating of PCL film effectively reduces the amount of adhered bovine serum albumin (BSA) on the surface of 316L SS in a bicinchoninic acid protein assay. PCL is both biodegradable and biocompatible, suggesting the potential for the surface modification of implants used in human bodies; in these applications, excellent corrosion resistance and anticoagulant properties are necessary.

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

OBJECTIVE

To investigate the cytotoxicity of nickel-titanium (NiTi) esthetic orthodontic archwires with different surface coatings.

MATERIALS AND METHODS

Three fully coated, tooth-colored NiTi wires (BioCosmetic, Titanol Cosmetic, EverWhite), two ion-implanted wires (TMA Purple, Sentalloy High Aesthetic), five uncoated NiTi wires (BioStarter, BioTorque, Titanol Superelastic, Memory Wire Superelastic, and Sentalloy), one β-titanium wire (TMA), and one stainless steel wire (Stainless Steel) were considered for this study. The wire samples were placed at 37°C in airtight test tubes containing Dulbecco's Modified Eagle's Medium (0.1 mg/mL) for 1, 7, 14, and 30 days. The cell viability of human gingival fibroblasts (HGFs) cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by a two-way analysis of variance (α  =  .05).

RESULTS

The highest cytotoxic effect was reached on day 30 for all samples. The archwires exhibited a cytotoxicity on HGFs ranging from "none" to "slight," with the exception of the BioTorque, which resulted in moderate cytotoxicity on day 30. Significant differences were found between esthetic archwires and their uncoated pairs only for BioCosmetic (P  =  .001) and EverWhite (P < .001).

CONCLUSIONS

Under the experimental conditions, all of the NiTi esthetic archwires resulted in slight cytotoxicity, as did the respective uncoated wires. For this reason their clinical use may be considered to have similar risks to the uncoated archwires.

Possible implications of Ni(II) on oral IL-1β-induced inflammatory processes

OBJECTIVES

Nickel (Ni) is one of the main metal elements in orthodontic and prosthetic devices. Different effects of Ni are described ranging from an induction of local inflammation to allergy and cancerous/mutagenic properties. Inflammatory reactions are frequently observed in the oral cavity, but the interrelationship of Ni with those events is still unknown. Therefore, we focused on the impact of Ni on inflammation in vitro.

METHODS

In accordance to previous immersion tests of our lab, human gingival fibroblasts (HGFs) (n=6) were exposed to a pro-inflammatory environment using interleukin-1 beta (IL-1β) and additionally stimulated with different Ni(II) concentrations (400 and 4000ng/ml). At varying time points the expression of pro- and anti-inflammatory as well as matrix degeneration proteins, i.e. MMPs, were analyzed. Furthermore, proliferation assays, wound healing tests and the detection of NF-κB activation were conducted. Unstimulated HGFs served as control.

RESULTS

Our experiments showed that low clinical average Ni(II) levels did not alter pro-inflammatory cytokines significantly compared to control (p>0.05). Instead, a 10-fold higher dose up-regulated these mediators significantly in a time-dependent manner (p<0.01). This was even more pronounced combining both Ni(II) concentrations with an inflammatory condition (p<0.001), MMP expressions were in line with our findings (p<0.001). The mRNA data were supported by proliferation and wound closure assays (p<0.001). However, the combination of both stimuli induced contradictory results. Analyzing NF-κB activation revealed that our results may be in part attributed to NF-κB.

SIGNIFICANCE

Our in vitro study implicated that Ni(II) has various modifying effects on IL-1β-induced inflammatory processes depending on the concentration.

Translation control of TAK1 mRNA by hnRNP K modulates LPS-induced macrophage activation

Macrophage activation by bacterial lipopolysaccharides (LPS) is induced through Toll-like receptor 4 (TLR4). The synthesis and activity of TLR4 downstream signaling molecules modulates the expression of pro- and anti-inflammatory cytokines. To address the impact of post-transcriptional regulation on that process, we performed RIP-Chip analysis. Differential association of mRNAs with heterogeneous nuclear ribonucleoprotein K (hnRNP K), an mRNA-specific translational regulator in differentiating hematopoietic cells, was studied in noninduced and LPS-activated macrophages. Analysis of interactions affected by LPS revealed several mRNAs encoding TLR4 downstream kinases and their modulators. We focused on transforming growth factor-β-activated kinase 1 (TAK1) a central player in TLR4 signaling. HnRNP K interacts specifically with a sequence in the TAK1 mRNA 3' UTR in vitro. Silencing of hnRNP K does not affect TAK1 mRNA synthesis or stability but enhances TAK1 mRNA translation, resulting in elevated TNF-α, IL-1β, and IL-10 mRNA expression. Our data suggest that the hnRNP K-3' UTR complex inhibits TAK1 mRNA translation in noninduced macrophages. LPS-dependent TLR4 activation abrogates translational repression and newly synthesized TAK1 boosts macrophage inflammatory response.

Effects of intraoral aging on surface properties of coated nickel-titanium archwires

OBJECTIVE

To evaluate the effects of intraoral aging on surface properties of esthetic and conventional nickel-titanium (NiTi) archwires.

MATERIALS AND METHODS

Five NiTi wires were considered for this study (Sentalloy, Sentalloy High Aesthetic, Superelastic Titanium Memory Wire, Esthetic Superelastic Titanium Memory Wire, and EverWhite). For each type of wire, four samples were analyzed as received and after 1 month of clinical use by an atomic force microscope (AFM) and a scanning electronic microscope (SEM). To evaluate sliding resistance, two stainless steel plates with three metallic or three monocrystalline brackets, bonded in passive configuration, were manufactured; four as-received and retrieved samples for every wire were pulled five times at 5 mm/min for 1 minute by means of an Instron 5566, recording the greatest friction value (N). Data were analyzed by one-way analysis of variance and by Student's t-test.

RESULTS

After clinical use, surface roughness increased considerably. The SEM images showed homogeneity for the as-received control wires; however, after clinical use esthetic wires exhibited a heterogeneous surface with craters and bumps. The lowest levels of friction were observed with the as-received Superelastic Titanium Memory Wire on metallic brackets. When tested on ceramic brackets, all the wires exhibited an increase in friction (t-test; P < .05). Furthermore, all the wires, except Sentalloy, showed a statistically significant increase in friction between the as-received and retrieved groups (t-test; P < .05).

CONCLUSION

Clinical use of the orthodontic wires increases their surface roughness and the level of friction.

Effect of pH on in vitro biocompatibility of orthodontic miniscrew implants

Background

Although the clinical use of miniscrews has been investigated on a large scale, little is known about their biocompatibility. Since low pH can affect corrosion resistance, the aim of this study was to evaluate the cytotoxic effect of orthodontic miniscrews in different pH conditions.

Methods

Four orthodontic miniscrews of stainless steel and grade IV and grade V titanium were immersed in a pH 7 and pH 4 saline solution for 1, 7, 14, 21, 28, and 84 days. Human osteogenic sarcoma cells (U2OS), permanent human keratinocytes (HaCat), and primary human gingival fibroblasts (HGF) were exposed to eluates, and the mitochondrial dehydrogenase activity was measured after 24 h to assess the cytoxicity. The results were analyzed using the Mann-Whitney U test (P < 0.05).

Results

When exposed to pH 7-conditioned eluates, the cell lines showed an even greater viability than untreated cells. On the contrary, the results revealed a statistically significant decrease in U2OS, HaCat, and HGF viability after exposure to eluates obtained at pH 4. Among the cell lines tested, HGF showed the most significant decrease of mitochondrial activity. Interestingly, grade V titanium miniscrews caused highest toxic effects when immersed at pH 4.

Conclusions

The results suggested that at pH 7, all the miniscrews are biocompatible while the eluates obtained at pH 4 showed significant cytotoxicity response. Moreover, different cell lines can produce different responses to miniscrew eluates.

Effect of nickel chloride on cell proliferation

Objective:

Metal alloys used in dentistry and in other biomedical fields may release nickel ions in the oral environment. The release of nickel might influence the normal biological and physiological processes, including tissue wound healing, cell growth and proliferation. The aim of this study was to evaluate in vitro the effects of nickel ions on cell cycle, viability and proliferation.

Materials and Methods:

Human osteosarcoma cells (U2OS) and human keratinocytes (HaCat) were exposed to different nickel chloride (NiCl₂) concentrations (0 - 5mM) for various periods exposure. The viability of cultured cells was estimated by flow cytometry using Annexin V-FITC and Propidium Iodide (PI). Cell proliferation was evaluated by using carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and flow cytometry. Finally, the effects of NiCl₂ on cell cycle were assessed and quantified by flow cytometry. Statistical analysis was performed by means of ANOVA followed by Tukey’s test.

Results:

NiCl₂ induced a dose and time dependent decrease in cell viability. After 24h, 1mM NiCl₂ caused a similar and significant reduction of viability in U2OS and HaCat cells, while higher NiCl₂ concentrations and longer exposure times showed a reduced cytotoxic effect in HaCat as compared to U2OS cells.

Exposure to NiCl₂ caused a dose- and time-dependent inhibition of cell proliferation in both cell lines tested, with a prominent effect on U2OS cells. Furthermore, both cell lines exposed to NiCl₂ exhibited significant changes in cell cycle distribution after 24h exposure 2mM NiCl2, as compared to untreated cells (p<0.05).

Conclusion:

Our results indicate that release of nickel ions may affect cell proliferation. The inhibition of cell growth by NiCl2 is mediated by both cell cycle arrest and by induction of cell death.

The upregulation of tumour necrosis factor-α and surface antigens expression on macrophages by bisphenol A-glycidyl-methacrylate

AIM

To evaluate the expression of tumour necrosis factor-α and surface antigens by bisphenol A-glycidyl-methacrylate (BisGMA) on murine macrophage cell line RAW264.7.

METHODOLOGY

Cytotoxicity was measured by tetrazolium bromide reduction assay. Tumour necrosis factor (TNF)-α was analysed by enzyme-linked immunosorbent assay. Cell surface antigens were investigated by flowcytometry. Statistical analyses were performed using anova followed by the Bonferroni's t-test for multigroup comparisons.

RESULTS

BisGMA exhibited cytotoxicity to RAW264.7 in a dose-dependent manner (P < 0.05) during 2-h incubation period. BisGMA was found to increase TNF-α secretion in a dose-dependent manner (P < 0.05). In addition, CD11, CD14, CD45, CD54, CD40, CD80, and MHC II were significantly stimulated by BisGMA in a dose-dependent manner (P < 0.05). However, MHC I expression was not affected by BisGMA (P > 0.05).

CONCLUSIONS

Taken together, the ability of macrophages to induce an appropriate immune response when exposed to BisGMA has the potential to upregulate TNF-α production and expression of surface antigens.

Immunomodulatory activity of andrographolide on macrophage activation and specific antibody response

AIM

To investigate the immunomodulatory effects of andrographolide on both innate and adaptive immune responses.

METHODS

Andrographolide (10 microg/mL in vitro or 1 mg/kg in vivo) was used to modulate LPS-induced classical activated (M1) or IL-4-induced alternative activated (M2) macrophages in vitro and humor immune response to HBsAg in vivo. Cytokine gene expression profile (M1 vs M2) was measured by real-time PCR, IL-12/IL-10 level was detected by ELISA, and surface antigen expression was evaluated by flow cytometry, whereas phosphorylation level of ERK 1/2 and AKT was determined by Western blot. The level of anti-HBs antibodies in HBsAg immunized mice was detected by ELISA, and the number of HBsAg specific IL-4-producing splenocyte was enumerated by ELISPOT.

RESULTS

Andrographolide treatment in vitro attenuated either LPS or IL-4 induced macrophage activation, inhibited both M1 and M2 cytokines expression and decreased IL-12/IL-10 ratio (the ratio of M1/M2 polarization). Andrographolide down-regulated the expression of mannose receptor (CD206) in IL-4 induced macrophages and major histocompability complex/costimulatory molecules (MHC I, CD40, CD80, CD86) in LPS-induced macrophages. Correspondingly, anti-HBs antibody production and the number of IL-4-producing splenocytes were reduced by in vivo administration of andrographolide. Reduced phosphorylation levels of ERK1/2 and AKT were observed in macrophages treated with andrographolide.

CONCLUSION

Andrographolide can modulate the innate and adaptive immune responses by regulating macrophage phenotypic polarization and Ag-specific antibody production. MAPK and PI3K signaling pathways may participate in the mechanisms of andrographolide regulating macrophage activation and polarization.

Increased Biocompatibility and Bioactivity after Energetic PVD Surface Treatments

Ion implantation, a common technology in semiconductor processing, has been applied to biomaterials since the 1960s. Using energetic ion bombardment, a general term which includes conventional ion implantation plasma immersion ion implantation (PIII) and ion beam assisted thin film deposition, functionalization of surfaces is possible. By varying and adjusting the process parameters, several surface properties can be attuned simultaneously. Extensive research details improvements in the biocompatibility, mainly by reducing corrosion rates and increasing wear resistance after surface modification. Recently, enhanced bioactivity strongly correlated with the surface topography and less with the surface chemistry has been reported, with an increased roughness on the nanometer scale induced by self-organisation processes during ion bombardment leading to faster cellular adhesion processes.