Fabrication of Porous Aluminum Coating by Cored Wire Arc Spray for Anchoring Antifouling Hydrogel Layer.

Biofouling has been persisting as a worldwide problem due to the difficulties in finding efficient environment-friendly antifouling coatings for long-term applications. Developing novel coatings with desired antifouling properties has been one of the research goals for surface coating community. Recently hydrogel coating was proposed to serve as antifouling layer, for it offers the advantages of the ease of incorporating green biocides, and resisting attachment of microorganisms by its soft surface. Yet poor adhesion of the hydrogel on steel surfaces is a big concern. In this study, porous matrix aluminum coatings were fabricated by cored wire arc spray, and the sizes of the pores in the aluminum (Al) coatings were controlled by altering the size of the cored powder of sodium chloride. Silicone hydrogel was further deposited on the porous coating. The hydrogel penetrated into the open pores of the porous Al coatings, and the porous Al structure significantly enhanced the adhesion of the hydrogel. In addition, hydrogel coating exhibited very encouraging antifouling properties.

Recyclable heparin and chitosan conjugated magnetic nanocomposites for selective removal of low-density lipoprotein from plasma.

A new fabrication protocol is described to obtain heparin and chitosan conjugated magnetic nanocomposite as a blood purification material for removal of low-density lipoprotein (LDL) from blood plasma. The adsorbent could be easily separated with an external magnet for recyclable use since it had a magnetic core. The LDL level of plasma decreased by 67.3 % after hemoperfusion for 2 h. Moreover, the adsorbent could be recycled simply washing with NaCl solution. After eight cycles, the removal efficiency of the adsorbent was still above 50 %. The recyclable magnetic adsorbent had good blood compatibility due to the conjugation of heparin to the chitosan-coated magnetic nanocomposites. The fabricated magnetic adsorbent could be applied for LDL apheresis without side effects.

Effect of Initial Surface Scratches on the Cavitation Erosion Behavior of 316L Stainless Steel Substrates and 316L Stainless Steel Coatings.

Rough surfaces have been widely considered as negative factors affecting cavitation erosion resistance. However, this study presented the opposite result. Here, 316L stainless steel substrates and the arc-sprayed 316L stainless steel coatings were subjected to a specific grinding process that introduced scratches on the surfaces. The surface hardness values of these ground specimens were measured to evaluate the influence of the grinding-induced strain hardening. The cavitation erosion performance of the specimens was evaluated. The results showed that rough surfaces with scratches could enhance the cavitation erosion resistance, particularly at the early stage of cavitation erosion. The scratches had a greater effect on the cavitation erosion resistance of the coatings than on the substrates. Moreover, rough surfaces with initial surface scratches could extend the incubation period of the 316L stainless steel substrates due to the inhibition of the plastic deformation. The SEM observation showed that the scratch structure of the coating surface inhibited the growth of cracks and the propagation of cavitation pits. This study could also serve as a reference for investigating the cavitation erosion behaviors of materials with a particular surface feature.

Screening and Identification of Human Endogenous Retrovirus-K mRNAs for Breast Cancer Through Integrative Analysis of Multiple Datasets.

Objective: Human endogenous retroviruses (HERVs) make up 8% of the human genome. HERVs are biologically active elements related to multiple diseases. HERV-K, a subfamily of HERVs, has been associated with certain types of cancer and suggested as an immunologic target in some tumors. The expression levels of HERV-K in breast cancer (BCa) have been studied as biomarkers and immunologic therapeutic targets. However, HERV-K has multiple copies in the human genome, and few studies determined the transcriptional profile of HERV-K copies across the human genome for BCa. Methods: Ninety-one HERV-K indexes with entire proviral sequences were used as the reference database. Nine raw sequencing datasets with 243 BCa and 137 control samples were mapped to this database by Salmon software. The differential proviral expression across several groups was analyzed by DESeq2 software. Results: First, the clustering of each dataset demonstrated that these 91 HERV-K proviruses could well cluster the BCa and control samples when the normal controls were normal cells or healthy donor tissues. Second, several common HERV-K proviruses that are closely related with BCa risk were significantly differentially expressed (p adj < 0.05 and absolute log2FC > 1.5) in the tissues and cell lines. Additionally, almost all the HERV-K proviruses had higher expression in BCa tissue than in healthy donor tissue. Notably, we first found the expression of 17p13.1 provirus that located with TP53 should regulate TP53 expression in ER+ and HER2+ BCa. Conclusion: The expression profiling of these 91 HERV-K proviruses can be used as biomarkers to distinguish individuals with BCa and healthy controls. Some proviruses, especially 17p13.1, were strongly associated with BCa risk. The results suggest that HERV-K expression profiles may be appropriate biomarkers and targets for BCa.

Surface functionalization of TiO2 nanotubes with bone morphogenetic protein 2 and its synergistic effect on the differentiation of mesenchymal stem cells.

To investigate the influence of surface-functionalized substrates with nanostructures on the behaviors of mesenchymal stem cells, we conjugated bone morphogenetic protein 2 (BMP2) onto TiO(2) nanotubes with different diameter sizes of 30, 60, and 100 nm for in vitro study. Polydopamine was employed as the intermediate layer for the conjugation of BMP2. The successful conjugation of BMP2 onto TiO(2) nanotubes was revealed by field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Immunofluorescence staining of vinculin, osteocalcin (OCN), and osteopontin (OPN) revealed that BMP2-functionalized TiO(2) nanotubes was favorable for cell growth. More importantly, MSCs cultured onto BMP2-functionalized TiO(2) nanotubes displayed significantly higher (p < 0.05 or p < 0.01) differentiation levels of ALP and mineralization after 7 and 14 day cultures, respectively. The results suggested that surface functionalization of TiO(2) nanotubes with BMP2 was beneficial for cell proliferation and differentiation. The approach presented here has potential application for the development of titanium-based implants for enhanced bone osseointegration.

In-situ SEM observations of ultrasonic cavitation erosion behavior of HVOF-sprayed coatings.

Several typical high-velocity oxy-fuel (HVOF)-sprayed coatings, including WC-10Co4Cr coatings, Co-based coatings, WC-10Co4Cr/Co-based composite coatings, and Fe-based amorphous/nanocrystalline coatings were fabricated, and their cavitation behavior was evaluated in deionized water. Further, in-situ SEM surface observations were used to understand the microstructure of tested coatings. The results show that cavitation erosion initially occurred at pre-existing defects in the coatings. Meanwhile, it was found that cavitation erosion damage of the WC-10Co4Cr/Co-based composite coating, which contained a hard reinforcing phase (WC-10Co4Cr phase) and a soft matrix phase (Co-based phase), preferentially occurred at or around pores and microcracks in the reinforcement, rather than in the defect free matrix. This suggested that defects were a critical contributing factor to cavitation damage of the composite coatings. Furthermore, a mechanism was suggested to explicate the cavitation behavior of composite coatings. The approach of using in-situ SEM surface observations proved to be useful for the analysis of the cavitation mechanism of engineering materials and protective coatings.

[Intraoperative radiotherapy for 30 esophageal carcinoma patients].

OBJECTIVE: To analyze the complications and treatment results of intraoperative radiotherapy (IORT) for esophageal carcinoma. METHODS: Sixty patients with thoracic esophageal carcinoma underwent esophagectomy through right thoractomy, 30 patients of whom received IORT of 15 - 25 Gy. RESULTS: In patients who underwent IORT, 2 cases of pneumonitis, 1 case of anastomotic leak and 1 case of incisional wound infection were found. In patients underwent surgery only, 1 case of thoracic empyema and 1 case of anastomotic leak were found. All the complications ultimately healed. There was no operative mortality. During the follow-up of 3 years, in patients who underwent IORT, 2 of 3 died of radiation pneumonitis 24 and 26 months after IORT with one complicated with bronchoesophageal fistula. One of 3 died of multiple lung metastases. The 3-year survival rate was 88.0% (22/25) in IORT group and 76.0% (19/25) in surgery only group. CONCLUSION: Intraoperative radiotherapy can reduce locoregional recurrence if performed to thoracic esophageal carcinoma patients without surgical contraindication or distant metastasis. Radiation pneumonitis, a common complication difficult to manage, implies a poor prognosis and, consequently, the lung and bronchus should be protected from the radiation.

Effects of mesoporous SiO2 , Fe3 O4 , and TiO2 nanoparticles on the biological functions of endothelial cells in vitro.

To comparatively investigate the cytotoxicities of nanomaterials in circulation, in this study, three different types of nanoparticles (NPs; mesoporous SiO2, Fe3O4, and TiO2) with diameters of around 100 nm were synthesized. The morphologies, crystalline phases, and zeta potentials of those NPs were characterized by scanning electron microscopy, X-ray diffraction and zeta potential measurement, respectively. Then, we investigated the influences of different NPs on the biological functions of endothelial cells, in particular of the organelle of cells. The results indicated that different types of NPs had cytotoxic effects in a dose- and time-dependent manner, and there was no significant difference in cytotoxicity between SiO2 and Fe3O4 at concentrations <0.20 mg/mL. The shape and surface charges of NPs greatly affected cellular internalization. We found that cytoskeleton and integrity of cells were destroyed by different NPs. Additionally, the production of reactive oxygen species damaged the mitochondria of cells, in turn leading to cells apoptosis and death.

Effects of titanium nanoparticles on adhesion, migration, proliferation, and differentiation of mesenchymal stem cells.

BACKGROUND: The purpose of this study was to investigate the influences of nanoscale wear particles derived from titanium/titanium alloy-based implants on integration of bone. Here we report the potential impact of titanium oxide (TiO2) nanoparticles on adhesion, migration, proliferation, and differentiation of mesenchymal stem cells (MSC) from the cellular level to the molecular level in the Wistar rat. METHODS: A series of TiO2 nanoparticles (14 nm, 108 nm, and 196 nm) were synthesized and characterized by scanning electron microscopy and transmission electron microscopy, respectively. RESULTS: The TiO2 nanoparticles had negative effects on cell viability, proliferation, and the cell cycle of MSC in a dose-dependent and size-dependent manner. Confocal laser scanning microscopy was used to investigate the effects of particle internalization on adhesion, spreading, and morphology of MSC. The integrity of the cell membrane, cytoskeleton, and vinculin of MSC were negatively influenced by large TiO2 nanoparticles. CONCLUSION: The Transwell migration assay and a wound healing model suggested that TiO2 nanoparticles had a strong adverse impact on cell migration as particle size increased (P < 0.01). Furthermore, alkaline phosphatase, gene expression of osteocalcin (OC) and osteopontin (OPN), and mineralization measurements indicate that the size of the TiO2 nanoparticles negatively affected osteogenic differentiation of MSC.

Fabrication of selenium-deposited and chitosan-coated titania nanotubes with anticancer and antibacterial properties.

To exploit titanium materials with anticancer and antibacterial properties, TiO(2) nanotubes arrays as nanoreservoirs for deposition of selenium were generated onto titanium substrates and then covered with chitosan layer. The deposition of selenium in TiO(2) nanotubes was performed with electrodeposition. The physical properties (surface morphologies, chemical compositions and wettability) of the substrates were characterized by field-emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and contact angle measurement, respectively. The growth behaviors of both healthy osteoblasts and cancerous osteoblasts on the substrates were investigated in vitro. The selenium-deposited and chitosan-coated TiO(2) nanotubes substrates (TiO(2) nanotubes-Se-Chi) demonstrated great potential for promoting the proliferation of healthy osteoblasts and inhibiting the growth of cancerous osteoblasts. Meanwhile, the TiO(2) nanotubes-Se-Chi substrates displayed a sustained release of selenium for 21 days. The antibacterial properties of the prepared substrates were evaluated with Escherichia coli (E. coli). The result showed that TiO(2) nanotubes-Se-Chi substrates had long term antibacterial capacity. The approach in this study provides an alternative to fabricate anticancer and antibacterial titanium-based implants for potential clinical application.

Construction of microenvironment onto titanium substrates to regulate the osteoblastic differentiation of bone marrow stromal cells in vitro and osteogenesis in vivo.

To mimic the extracellular matrix of natural bone, apatite/gelatin composite was deposited onto nanostructured titanium substrates via a coprecipitation method, which was pretreated by potassium hydroxide and heat treatment to generate an anticorrosive nanostructured layer. The successful formation of the apatite/gelatin nanocomposite onto titanium surfaces was revealed by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, atomic force microscopy (AFM), and thin film X-ray diffraction (TF-XRD) measurements, respectively. The immunofluorescence staining of vinculin revealed that the apatite/gelatin nanocomposite deposited titanium substrate was favorable for cell adhesion. More importantly, bone marrow stromal cells cultured onto the apatite/gelatin nanocomposite deposited titanium substrates displayed significantly higher (p < 0.05 or p < 0.01) proliferation and differentiation levels of alkaline phosphatase, mRNA expressions of osteocalcin (OC), osteopontin (OPN), and collagen type I (Col I), and OC content after culture for 7, 14, and 21 days, respectively, which was also revealed by the immunofluorescence analysis of OC and OPN expression. The deposition of apatite/gelatin nanocomposite improved bone density (p < 0.05) and bone-implant contact rate (p < 0.05), which was reflected by microcomputed tomography analysis and histological evaluation in vivo using a rabbit model. This work provides an approach to fabricate high-performance titanium-based implants with enhanced bone osseointegration.