In vitro bioactivity, tribological property, and antibacterial ability of Ca–Si-based coatings doped with cu particles in-situ fabricated by laser cladding

2018 ◽  
Vol 124 (3) ◽  
Author(s):  
Baoping Hou ◽  
Zhao Yang ◽  
Yuling Yang ◽  
Erlin Zhang ◽  
Gaowu Qin
Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 355 ◽  
Author(s):  
Patricia Mazón ◽  
Patricia Ros-Tárraga ◽  
Sara Serena ◽  
Luis Meseguer-Olmo ◽  
Piedad De Aza

Two dense biphasic ceramics, with a hypereutectic composition of 30 wt % CaSiO3–70 wt % Ca3(PO4)2, were synthesized by a solid-state reaction of homogeneous pressed combinations of previously synthesized synthetic CaSiO3 and Ca3(PO4)2 powders. The objective was to produce a dense structure to generate large enough in situ pores for the ceramic to be used in tissue engineering. To develop such a structure, two grain sizes of CaSiO3 were used (63–100 µm and 100–150 μm) and some of their properties were studied in vitro, as they are relevant for tissue engineering. X-ray diffraction analysis, μ-Raman spectroscopy, diametrical compression test, and scanning electron microscopy with elemental mapping showed a coarse-grained homogeneous microstructure for the materials, which consisted of wollastonite (α-CaSiO3) and tricalcium phosphate (α-Ca3(PO4)2), with adequate mechanical properties for implantation. In vitro bioactivity was evaluated in simulated body fluid (SBF) by exploring a hydroxyapatite (HA)-like formation. The results showed that tricalcium phosphate grains dissolved more preferentially than those of wollastonite, but not fast enough to leave a pore before the surface was coated with an HA-like layer after soaking only for three days. Biocompatibility was evaluated by in vitro cell experiments, which showed cell proliferation, adhesion, and spreading on the ceramic surface. This ceramic is expected to be used as a bone graft substitute.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3772
Author(s):  
Zahra Ansari ◽  
Mahdi Kalantar ◽  
Alessandra Soriente ◽  
Ines Fasolino ◽  
Mahshid Kharaziha ◽  
...  

Ti6Al4V alloy is still attracting great interest because of its application as an implant material for hard tissue repair. This research aims to produce and investigate in-situ chitosan/hydroxyapatite (CS/HA) nanocomposite coatings based on different amounts of HA (10, 50 and 60 wt.%) on alkali-treated Ti6Al4V substrate through the sol-gel process to enhance in vitro bioactivity. The influence of different contents of HA on the morphology, contact angle, roughness, adhesion strength, and in vitro bioactivity of the CS/HA coatings was studied. Results confirmed that, with increasing the HA content, the surface morphology of crack-free CS/HA coatings changed for nucleation modification and HA nanocrystals growth, and consequently, the surface roughness of the coatings increased. Furthermore, the bioactivity of the CS/HA nanocomposite coatings enhanced bone-like apatite layer formation on the material surface with increasing HA content. Moreover, CS/HA nanocomposite coatings were biocompatible and, in particular, CS/10 wt.% HA composition significantly promoted human mesenchymal stem cells (hMSCs) proliferation. In particular, these results demonstrate that the treatment strategy used during the bioprocess was able to improve in vitro properties enough to meet the clinical performance. Indeed, it is predicted that the dense and crack-free CS/HA nanocomposite coatings suggest good potential application as dental implants.


2015 ◽  
Vol 35 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Chi-Sheng Chien ◽  
Yu-Sheng Ko ◽  
Tsung-Yuan Kuo ◽  
Tze-Yuan Liao ◽  
Huan-Chang Lin ◽  
...  

2005 ◽  
Vol 284-286 ◽  
pp. 761-764
Author(s):  
Gabriela A. Silva ◽  
Olga P. Coutinho ◽  
Rui L. Reis

In the present work we describe the synthesis of starch-based/BG 45S5 particles and their in vitro bioactivity behaviour by means of immersion in a simulated body fluid. The composite particles have shown to form a layer of Ca-P at their surface, whose nature was confirmed by chemical and morphological analysis. In order to evaluate the ability of these particles to be used as carriers for cell culture, undifferentiated rat cells were selected and parameters like cell adhesion, proliferation and expression of osteoblastic markers, were evaluated. The starch-based micro-particles have shown to support cellular activity, allowing cells to attach, proliferate and express specific markers while cultured in the particles surface. The final goal is to be able to use these particles as carriers for cells and simultaneously as in-situ forming constructs for tissue engineering and regenerative medicine applications.


Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.


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