Concept

Hydroxyapatite

Publications associées (24)

Evidence of a transient phase during the hydrolysis of calcium-deficient hydroxyapatite

In the present paper, calcium deficient hydroxyapatite (Ca-def OHAP) has been examined in a transmission electron microscope. During the observation, the initial Ca-def OHAP was seen to transform first into a transient intermediate phase, then to a final, ...

WALTER DE GRUYTER GMBH2022

Catechol Containing Polyelectrolyte Complex Nanoparticles as Local Drug Delivery System for Bortezomib at Bone Substitute Materials

Martin Guillermo Mueller, Jeremy Pak Hei Wong

The proteasome inhibitor bortezomib (BZM) is one of the most potent anti-cancer drugs in the therapy of multiple myeloma. In this study, an adhesive drug delivery system (DDS) for BZM was developed. Therefore, we extended the present DDS concept of polyele ...

2020

Operando XANES from first-principles and its application to iridium oxide

Nicola Marzari, Francesco Nattino

Efficient electro-catalytic water-splitting technologies require suitable catalysts for the oxygen evolution reaction (OER). The development of novel catalysts could benefit from the achievement of a complete understanding of the reaction mechanism on irid ...

ROYAL SOC CHEMISTRY2020

Adsorption of HPDX and CaHPOx (x=1, ...,4) molecules on anatase TiO2 (001) surfaces

Alfonso Baldereschi

perform DFT calculations within the COSMO framework to study the adsorption properties of the CaHPOx (x = 1,...,4) phosphate family, and of the related HPOx acids, on a paradigmatic anatase (001) surface. Of particular interest is CaHPO4, a precursor of hy ...

ELSEVIER SCIENCE BV2019

Structural description of surfaces and interfaces in biominerals by DNP SENS

David Lyndon Emsley

Biological mineralized tissues are hybrid materials with complex hierarchical architecture composed of biominerals often embedded in an organic matrix. The atomic-scale comprehension of surfaces and organo-mineral interfaces of these biominerals is of para ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2019

Non-setting, injectable biomaterials containing particulate hydroxyapatite can increase primary stability of bone screws in cancellous bone

Dominique Pioletti, Ulrike Kettenberger

BACKGROUND: Fracture fixation in weak bone is still a clinical challenge. Screw augmentation was shown to successfully increase their primary stability. The currently used calcium phosphate or polymeric bone cements, however, present important drawbacks su ...

2018

Calcium phosphate formation on titanium-based surfaces: bioactivity evaluated by in vitro methods

Weitian Zhao

The prediction of implant behaviors in vivo by the use of easy-to-perform in vitro methods is of great interest in biomaterials research. In the field of bone implants, it is commonly accepted that a spontaneous formation of a hydroxyapatite (HA) layer on ...

EPFL2018

In vitro and in vivo investigation of bisphosphonate-loaded hydroxyapatite particles for peri-implant bone augmentation

Dominique Pioletti, Ulrike Kettenberger

Locally applied bisphosphonates, such as Zoledronate, have been shown in several studies to inhibit peri-implant bone resorption and recently to enhance peri-implant bone formation. Studies have also demonstrated positive effects of hydroxyapatite particle ...

Wiley-Blackwell2017

A comparative study of simulated body fluids in the presence of proteins

Paul Bowen, Jacques Lemaître, Weitian Zhao

Simulated body fluid (SBF) is widely used as part of an in vitro method to evaluate implant materials such as their apatite forming ability (AFA), a typical indication of potential bone-bonding ability in vivo. We report the use of carbonate-buffered SBFs ...

2017

Active Agent-Particle Combination Supporting Bone Regeneration

Dominique Pioletti, Ulrike Kettenberger

The invention provides for a bioactive composition comprising solid particles, such as e.g. calcium phosphate particles, loaded with an active agent, preferably an osteoconductive/osteoinductive agent or an anti-resorptive agent like a bisphosphonate. The ...

2017

Variability of the pullout strength of cancellous bone screws with cement augmentation

Dominique Pioletti

Background: orthopaedic surgeons often face clinical situations where improved screw holding power in cancellous bone is needed. Injectable calcium phosphate cements are one option to enhance fixation. Methods: paired screw pullout tests were undertaken in ...

Elsevier2015

Strontium hydroxyapatite and strontium carbonate as templates for the precipitation of calcium-phosphates in the absence and presence of fluoride

Janet Gordon Hering, Michèle Bernadette Heeb

The heterogeneous precipitation of calcium phosphates on calcium hydroxyapariLe (Ca-10(PO4)(4)OH)(2) or HAP) in the presence arid absence of fluoride is important in the formation of bone and teeth, protection against tooth decay, dental and skeletal fluor ...

Elsevier Science Bv2014

Development of a Bisphosphonate Delivering Hydrogel for the Augmentation of Impaired Peri-Implant Bone

Ulrike Kettenberger

Osteoporosis is a major health problem in our aging society. This metabolic disease, which is characterized by a deterioration of the bone microarchitecture and a significant loss of bone mass, is affecting a rising number of mostly elderly patients. The m ...

EPFL2014

Development of sol-gel-derived multi-wall carbon nanotube/hydroxyapatite nanocomposite powders for bone substitution

Hossein Najafi

Carbon nanotubes with unique physical and mechanical properties have shown great potential for biological applications, including tissue engineering and mimicking the structure and properties of human bones. In the present work, sol-gel synthesized nanocom ...

Sage Publications Ltd2014

Uptake of Fluoride from Aqueous Solution on Nano-Sized Hydroxyapatite: Examination of a Fluoridated Surface Layer

Janet Gordon Hering

Hydroxyapatite (Ca-10(PO4)(6)(OH)(2), HAP), both as a synthetic material and as a constituent of bone char, can serve as an effective and relatively inexpensive filter material for fluoride (F-) removal from drinking water in low-income countries. Fluoride ...

2012

Injectable calcium phosphate cement for augmentation around cancellous bone screws. In vivo biomechanical studies

Dominique Pioletti, Vincent Stadelmann

In lower cancellous apparent bone density, it can be difficult to achieve adequate screw fixation and hence stable fracture fixation. Different strategies have been proposed, one of them is through augmentation using calcium phosphate cement in the region ...

Elsevier2012

Osteoconductive surfaces generated from peptide functionalized poly(2-hydroxyethyl methacrylate-co-2-(methacryloyloxy)ethyl phosphate) brushes

Harm-Anton Klok, Dusko Paripovic

Modification of bone implant materials with biofunctional surfaces that facilitate osteoblast adhesion and promote matrix mineralization is an attractive strategy to improve osseointegration. This manuscript discusses the preparation and properties of RGD ...

Royal Society of Chemistry2012

Inclusion of carbon nanotubes in a hydroxyapatite sol-gel matrix

Hossein Najafi

In this study, the inclusion of multi-walled carbon nanotubes as the second phase in the hydroxyapatite matrix, in order to improve the mechanical strength, has been performed via the sol-gel process. The stability of carbon nanotube sol with the changes o ...

2009

Nanohydroxyapatite/poly(ester urethane) scaffold for bone tissue engineering

Pierre-Etienne Bourban, Carole Boissard

Biodegradable viscoelastic poly(ester urethane)-based scaffolds show great promise for tissue engineering. In this study, the preparation of hydroxyapatite nanoparticles (nHA)/poly(ester urethane) composite scaffolds using a salt-leaching-phase inverse pro ...

Elsevier2009

Electron microscopy of biomaterials based on hydroxyapatite

Philippe Buffat, Elena Suvorova Buffat

Three types of biomaterials based on hydroxyapatite are synthesized and investigated. Hydroxyapatite nanocrystals or microcrystals precipitated from low-temperature aqueous solutions serve as the initial material used for preparing spherical porous granule ...

2006