High-Porosity Poly(ε-Caprolactone)/Mesoporous Silicon Scaffolds: Calcium Phosphate Deposition and Biological Response to Bone Precursor Cells

2008 ◽  
Vol 14 (1) ◽  
pp. 195-206 ◽  
Author(s):  
Melanie A. Whitehead ◽  
Dongmei Fan ◽  
Priyabrata Mukherjee ◽  
Giridhar R. Akkaraju ◽  
Leigh T. Canham ◽  
...  
2008 ◽  
Vol 14 (1) ◽  
pp. 195-206 ◽  
Author(s):  
Melanie A. Whitehead ◽  
Dongmei Fan ◽  
Priyabrata Mukherjee ◽  
Giridhar R. Akkaraju ◽  
Leigh T. Canham ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 613
Author(s):  
Sankar Sekar ◽  
Sejoon Lee

High-quality silicon (Si) nanocrystals that simultaneously had superior mesoporous and luminescent characteristics were derived from sticky, red, and brown rice husks via the facile and cost-effective magnesiothermic reduction method. The Si nanocrystals were confirmed to comprise an aggregated morphology with spherical nanocrystals (e.g., average sizes of 15–50 nm). Due to the surface functional groups formed at the nanocrystalline Si surfaces, the Si nanocrystals clearly exhibited multiple luminescence peaks in visible-wavelength regions (i.e., blue, green, and yellow light). Among the synthesized Si nanocrystals, additionally, the brown rice husk (BRH)-derived Si nanocrystals showed to have a strong UV absorption and a high porosity (i.e., large specific surface area: 265.6 m2/g, small average pore diameter: 1.91 nm, and large total pore volume: 0.5389 cm3/g). These are indicative of the excellent optical and textural characteristics of the BRH-derived Si nanocrystals, compared to previously reported biomass-derived Si nanocrystals. The results suggest that the biomass BRH-derived Si nanocrystals hold great potential as an active source material for optoelectronic devices as well as a highly efficient catalyst or photocatalyst for energy conversion devices.


2012 ◽  
Vol 101A (1) ◽  
pp. 13-22 ◽  
Author(s):  
Kate Cameron ◽  
Paul Travers ◽  
Chaman Chander ◽  
Tom Buckland ◽  
Charlie Campion ◽  
...  

Biomaterials ◽  
2007 ◽  
Vol 28 (32) ◽  
pp. 4788-4794 ◽  
Author(s):  
Mark R. Appleford ◽  
Sunho Oh ◽  
Judith A. Cole ◽  
Jiri Protivínský ◽  
Joo L. Ong

2007 ◽  
Vol 330-332 ◽  
pp. 625-628
Author(s):  
Ying Chun Wang ◽  
Jian Guo Li ◽  
Yaohe Zhou

Hydroxyapatite(HAP) has excellent osteoconductive properties. By controlling the Ca/P ratio better biphasic calcium phosphate ceramics can be produced than pure HAP ceramics. β- calcium pyrophosphate(β-Ca2P2O7) is a new biodegradable ceramic material and its biological response is quite similar to HAP. Obtaining HAP and other bioactive calcium phosphate ceramic coatings has been a popular research field in the past. In our research a new bioceramic composite coating was obtained by laser cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on the metal substrate. Its main constituents are HAP and β-Ca2P2O7. The microstructure of the coating consists of minute granular HAP that is distributed among the overlapped club-shaped or needle-like β-Ca2P2O7. The hardness distribution in the cladding layer is even and its value is much higher than that in the substrate. There is a bonded structure of the epitaxial planar growth between the substrate and cladding layer, and both a typical cellular microstructure in the middle and an equiaxed microstructure at the top of the cladding layer.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 823
Author(s):  
Monika Furko ◽  
Csaba Balázsi

Calcium phosphate based bioactive ceramics (CPCs) can be successfully applied as implant coatings since they are chemically similar to the inorganic constituent of hard tissues (bones, teeth). Nowadays, in orthopedic surgeries, it is still common to use metallic implants. However, the biological response of the human body to these foreign materials can be adverse, causing the failure of implant materials. This disadvantage can be avoided by bioactive coatings on the surface of implants. CPCs can be prepared by different routes that provide coatings of different quality and properties. In our paper, we compared the morphological, chemical, and biological properties of CPC coatings prepared by the pulse current electrochemical method. The size and thickness of the pulse current deposited platelets largely depended on the applied parameters such as the length of ton and the current density. The decrease in the ton/toff ratio resulted in thinner, more oriented platelets, while the increase in current density caused a significant decrease in grain size. The higher pH value and the heat treatment favored the phase transformation of CPCs from monetite to hydroxyapatite. The contact angle measurements showed increased hydrophilicity of the CPC sample as well as better biocompatibility compared to the uncoated implant material.


2012 ◽  
Vol 529-530 ◽  
pp. 421-425
Author(s):  
Edirlaine Soares Silva ◽  
Deny Gomes de Freitas ◽  
Sidney Nicodemos da Silva

Dermal fillers are injectable implants made of biological materials (collagen, autologous fat and hyaluronic acid animal) or synthetic (PMMA microparticles of hydroxyapatite and non-animal hyaluronic acid), biodegradable or not, that include features such as ideal biocompatibility, durability, non-profile migration and ability to promote a smooth, natural-looking correction. Its main indication is intended to treat contour defects caused by aging, photo damage, disease, trauma or scarification. The fact of biodegradable fillers are absorbed within a year after application resulted in the emergence of products permanent and semi-permanent to offer patients long-lasting effects. Currently, one of the most effective strategies has been the development of scaffolds formed by combining two or more biomaterials seeking the restoration of tissue function. The bioceramic associated with water-soluble polymers have been developed as substitutes for the repair of soft tissues with optimal biological response. The objective of this study was to process and characterize a composite hydrogel in the form of hyaluronic acid (HA) microspheres and biphasic calcium phosphate (BCP) in order injectable applications for repair of soft tissue. The powders of HA and BCP were characterized by Infrared Spectroscopy Fourier Transform (FTIR) and X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The characterization of the hydrogel injectability pure and the composite with different ratios of HA and BCP was performed. The components were characterized compatible for use as dermal fillers. The composite of hyaluronic acid (HA) and biphasic calcium phosphate (BCP) had adequate characterization and injetabilidade proving to be a potential candidate for restoration of soft tissue.


1991 ◽  
Vol 256 ◽  
Author(s):  
A. G. Cullis ◽  
L. T. Canham ◽  
O. D. Dosser

ABSTRACTThis detailed electron microscope study of porous silicon compares the different structures of macro-, meso- and microporous material. Mesoporous silicon of high porosity (∼-80%) exhibits efficient red photoluminescence at room temperature. Transmission electron microscopy provides strong direct evidence that this visible luminescence arises from dramatic carrier confinement in quantum-size, crystalline silicon structures. Images of undulating, interconnected ‘quantum wires’ of widths <3nm are shown.


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