402 research outputs found

    Decreased Fibroblast and Increased Osteoblast Functions on Ionic Plasma Deposited Nanostructured Ti Coatings

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    Bioactive coatings are in high demand to control cellular functions for numerous medical devices. The objective of this in vitro study was to characterize for the first time fibroblast (fibrous scar tissue forming cells) adhesion and proliferation on an important polymeric biomaterial (silicone) coated with titanium using a novel ionic plasma deposition (IPD) process. Fibroblasts are one of the first anchorage-dependent cells to arrive at an implant surface during the wound healing process. Persistent excessive functions of fibroblasts have been linked to detrimental fibrous tissue formation which may cause implant failure. The IPD process creates a surface-engineered nanostructure (with features usually below 100 nm) by first using a vacuum to remove all contaminants, then guiding charged metallic ions or plasma to the surface of a medical device at ambient temperature. Results demonstrated that compared to currently used titanium and uncoated silicone, silicone coated with titanium using IPD significantly decreased fibroblast adhesion and proliferation. Results also showed competitively increased osteoblast (bone-forming cells) over fibroblast adhesion on silicone coated with titanium; in contrast, osteoblast adhesion was not competitively increased over fibroblast adhesion on uncoated silicone or titanium controls. In this manner, this study strongly suggests that IPD should be further studied for biomaterial applications in which fibrous tissue encapsulation is undesirable (such as for orthopedic implants, cardiovascular components, etc.)

    Topography, substratum and benthic macrofaunal relationships on a tropical mesophotic shelf margin, central Great Barrier Reef, Australia

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    Habitats and ecological communities occurring in the mesophotic region of the central Great Barrier Reef (GBR), Australia, were investigated using autonomous underwater vehicle (AUV) from 51 to 145 m. High-resolution multibeam bathymetry of the outer-shelf at Hydrographers Passage in the central GBR revealed submerged linear reefs with tops at 50, 55, 80, 90, 100 and 130 m separated by flat, sandy inter-reefal areas punctuated by limestone pinnacles. Cluster analysis of AUV images yielded five distinct site groups based on their benthic macrofauna, with rugosity and the presence of limestone reef identified as the most significant abiotic factors explaining the distribution of macrofaunal communities. Reef-associated macrofaunal communities occurred in three distinct depth zones: (1) a shallow (75 m). The effects of depth and microhabitat topography on irradiance most likely play a critical role in controlling vertical zonation on reef substrates. The lower depth limits of zooxanthellate corals are significantly shallower than that observed in many other mesophotic coral ecosystems. This may be a result of resuspension of sediments from the sand sheets by strong currents and/or a consequence of cold water upwelling

    The effect of chrysin�curcumin-loaded nanofibres on the wound-healing process in male rats

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    Aim: The aim of the present study was to produce chrysin�curcumin-loaded PCL-PEG nanofibres by an electrospinning technique and to evaluate the biological activity of the chrysin�curcumin-loaded PCL-PEG fibres for wound healing and its related genes using in vivo methods. Materials and methods: The electrospinning method was carried out for the preparation of the chrysin, curcumin and chrysin�curcumin-loaded PCL-PEG nanofibres with different concentrations. FTIR and SEM were performed to characterize the chemical structures and morphology of the nanofibres. In vitro drug release, as well as in vivo wound-healing studies were investigated in male rats. The expressions of genes related to the wound-healing process were also evaluated by real-time PCR. Results: Our study showed that the chrysin�curcumin-loaded nanofibres have anti-inflammatory properties in several stages of the wound-healing process by affecting the IL-6, MMP-2, TIMP-1, TIMP-2 and iNOS gene expression. Our results demonstrated that the effect of the chrysin-loaded nanofibre, the curcumin-loaded nanofibre and the chrysin�curcumin-loaded nanofibre in the wound-healing process is dose dependent and in accordance with the obtained results in that it might affect the inflammation phase more than the other stages of the wound-healing process. Conclusion: We have introduced chrysin�curcumin-loaded PCL-PEG nanofibres as a novel compound for shortening the duration of the wound-healing process. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

    Development and characterization of a novel conductive polyaniline-g-polystyrene/Fe 3 O 4 nanocomposite for the treatment of cancer

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    The goal of this study is to synthesize, characterize and investigate some physicochemical properties of conductive polyaniline-g-polystyrene/Fe 3 O 4 (Fe 3 O 4 /PSt-g-PANi) nanocomposites. For this purpose, initially, Fe 3 O 4 nanoparticles were synthesized by a co-precipitation method. Then, the desired nanocomposite was synthesized in two steps. First, the atom transfer radical polymerization (ATRP) of styrene was performed using an ATRP initiator attached to the surface of Fe 3 O 4 nanoparticles, followed by functionalization of the Fe 3 O 4 -PSt with amine groups (�NH 2 ). Second, surface oxidative graft copolymerization of aniline was accomplished using the �NH 2 moieties on the Fe 3 O 4 /PSt-NH 2 as the anchoring sites. The prepared materials were characterized by various instruments, including TEM, SEM, TGA, EDX, FT-IR, XRD and conductivity measurements. The results indicated that the synthesized conductive polymer/Fe 3 O 4 nanocomposites had higher electrical conductivity and thermal resistance than those of the corresponding homopolymers. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
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