- Overview:
Inorganic phosphate-based compounds are key species relevant to a wide number of domains and applications.
Nature itself provides good examples
either as "biominerals" (found for example in the composition of bones, teeth as well as some pathological calcifications) or as phosphate-ore minerals
(on Earth but also in other contexts as on Mars or the Moon).
Calcium phosphates, in particular, occupy a very important place in various fields such as:
- Biomineralization (e.g. understanding the formation of calcifications in vivo, characterizing calcified tissues)
- Anthropology (e.g. analysis of sketetal remains, fossils, preservation of ancient DNA)
- Biomaterials science and biomedical engineering (e.g. developing bioactive systems for bone regeneration, nanomedicine, medical imaging...)
- Mineralogy (e.g. Terrestrial, Martian)
- Environmental sciences (e.g. sequestration of pollutants)
- Research interests:
I am interested in all these inspiring domains, which I am addressing via a combined approach involving (bio)materials science, bulk and surface
chemistry/functionalization, detailed physicochemical and thermodynamic characterization, structure/properties relationships, materials processing especially
via low temperature/cold sintering strategies, as well as modeling .
In several cases, the samples prepared/studied are complex, often nonstoichiometric
and involve substituting ions or adsorbed (bio)molecules/drugs in view of providing specific additional properties (e.g. antimicrobial, anticancer, hemostatic,
luminescent, cell-targeting...) and/or for mimicking natural compounds for a biomimetic/bio-inspired approach whenever possible. The conception of composite
and hybrid organic/inorganic materials is also often investigated. Finally, some of the strategies developed for CaP compounds can be transferred to other
relevant (hydr)oxide-based materials (e.g. low temperature processing of other metastable compounds by SPS or freeze-casting, etc.).
Some research axes:
- - Development of the "hydrated layer model" on bone apatite or their biomimetic analogs: synthesis and characterization of nanocrystalline biomimetic apatites, analysis of "non-apatitic" chemical environments on the surface of apatite nanocrystals, volume and surface properties, follow-up of biological properties.
- - Study of the thermodynamic properties of inorganic materials: mixed oxides and hydroxides, nanocrystalline apatites analogous to bone mineral, etc., and related micro- and macroscopic consequences. Review of thermodynamic data on apatites: doi:10.1016/j.jct.2014.09.012. Development of an additive thermodynamic model for the evaluation of thermodynamic properties of apatites containing various ions: Link to the free program of predictive thermodynamics Therm'AP (model now extanded also to other complex oxides)
- - Development of a new generation of « low temperature » bioactive and biodegradable bioceramics: Study of the consolidation of calcium phosphates by non-conventional techniques: Cold Sintering approaches, Spark Plasma Sintering at low temperature, Freeze-Casting etc. to nanocrystalline apatites, amorphous CaP and other metastable (hydr)oxides; soft-chemistry routes for the preparation of highly-reactive/bioactive systems. Physico-chemical and biological properties of the prepared compounds.
- - Surface ion exchanges / Adsorption: : ion exchange with biologically-active ions, study of the reversibility of the exchange, exchange mechanisms, adsorption isotherms, association with (and release of) active compounds (growth factors, enzymes, antibiotics, anti-cancerous drugs, DNA...). Development of "smart", stimuli-responsive/controlled release (in time and space) systems for biomedicine.
- - Development of hybrid organic/inorganic colloidal nanoparticles based on bio-inspired apatites for applications in therapeutics (oncology, hematology, dermatology… and for diagnosis purposes (colloidal luminescent nanoprobes, cell targeting).
- - Functionalization of the surface of CaP-based biomaterials and post-activation of other existing biomaterials (metals or other less bioactive ceramics); exploration of organic/inorganic interfaces.
- - Anthropology: Interaction DNA / nanocrystalline apatites. Physico-chemical characterization of skeletal remains (bones and teeth).
- - Study of the nucleation/growth of calcium phosphates on biomaterials based on metal (titanium…) or ceramics ; bioactive coatings.
- - Preparation of phosphates compounds and other complex (hydr)oxides (standards), e.g. for mineralogical investigations.
© 2021 All rights reserved • Christophe Drouet • Conception CREA2F