Functional Nanomaterials II-05.09.2007 New hybrid inorganic-organic nanomaterials obtained in hydrothermal conditions for regenerative medicine Roxana

Functional Nanomaterials II-05.09.2007

New hybrid inorganic-organic nanomaterials New hybrid inorganic-organic nanomaterials obtained in hydrothermal conditions for obtained in hydrothermal conditions for

regenerative medicineregenerative medicine

Roxana M. Piticescu, National R&D Institute for Non-ferrous and Rare Metals

102 Biruintei Blvd., Pantelimon, Ilfov, Romania

IMNR


IntroductionMaterials chemistry, synthesis methods for nanostructured

materials

Original resultsHybrid organic-inorganic compounds

Conclusions

Acknowledgement


Materials research involves two main domains of activity [1]:

Synthesis of novel materials for improving basic knowledge, making correlations between composition, chemical bonding, structure and resulting physical properties

New routes for producing materials by the development of economically cheaper processes

The optimization of the shape of materials (nano crystallites, thin films, single crystals…) for specific applications

[1] G. Demazeau, G. Goglio, A. Largeteau, Solvothermal processes in Materials Synthesis, Mater. Res. Soc. Symp. Proc. Vol. 878E, 2005

Introduction


IntroductionWhat we know from the literature data: 1.Hybrid materials synthesis routes: copolymerisation of organosilanes and metal alkoxides, encapsulation of organic components within sol-gel derived silica or metallic oxides, organic functionalisation of nanofillers, nanoclays or other compounds with lamellar structures

2. Strong chemical bonding between organic-inorganic phases enhance the mechanical properties of nanocomposites

3. Sol gel process drawbacks (large volume shrinkage due to the evaporation of large amount of solvent, small molecular hydrolysis by-products and poly-condensation reactions) limit its technological applications,

4. Fabrication ZnO nanostructured films and nanorods (diameter 90 nm, 1 micron lengths ) by CVD, PLD, electrodeposition, template methods presents some limitations to achieve a certain thickness and is incovenient for dopping when more dopants are used. ZnO-PVA was used due to well distributed ligand radicals on chain and the polymer chain limits the growth scale of ZnO core [5].

5. Fabrication of ZnO nanoparticles by thermooxidative degradation of ZnO complexes e.g.:[Zn(phen)2(H2O)2][Zn(phen)S2O3)2].4H2O [6]

[1]. Cuiming Wu &al, European Polymer Journal, 41, 1901-1908, (2005)[2]. Clement Sanchez &al, J.Mater.Chem., 15, 3559-3592 (2005)[3]. Eduardo Ruiz-Hitzky &al, J.Mater.Chem., 15, 3650-3662 (2005)[4]. Jui-Ming Yeh &al, Journal of Applied Polymer Science, 101, 1151-1159 (2006)[5].Ying He &all, J. Nanoparticles Res. 7, 307-310 (2005)[6]. A. Dumbrava&al., J. Therm. Analysis& Calorim., 79, 509-514 (2005)


Methods for the preparation of nanostructured compounds

Conventional Conventional methodsmethods

Form-in-place Form-in-place processesprocesses

Gas phase synthesis Gas phase synthesis methodsmethods

Wet chemical methodsWet chemical methods(“soft chemistry”)(“soft chemistry”)

Mechanical methods

Physical vapor deposition (PVD)

Laser ablation Hydrothermal and solvothermal synthesis

Solid-state synthesis

Chemical vapor deposition (CVD)

Microwave plasma synthesis

Sol-gel method

Spray pyrolysis

Vaporization-Condensation (VC) using Solar Physical Vapor Deposition (SPVD)

Pechini method

The reactivity of the precursors play an important role in the preparation of novel materialsMild thermodynamic conditions (in terms of pressure and temperature parameters) specific to hydrothermal or solvothermal reactions are able to initiate through chemical bounding directly from solutions new nanostructures

Introduction


Introduction

New Nanostructured

compounds

Previous original experimental works

Hydrothermal synthesis of nanostructured oxides, hybrids

organic-inorganic

Application in the field of Nanomedicine

Application in the field of Nanoelectronics

Application in the field of Functionally graded materials


The main goal is to prepare original nanostructured compounds: hybrid organic/inorganic powders using hydrothermal method in mild conditions.

The stabilization of hybrid organic/inorganic materials is favored by low temperature and high pressure values.

Pressure can be the autogenous pressure (the vapor pressure of components in solution) or a higher pressure due to the barbotage of an inert gas before heating.

Some examples of hybrid organic/inorganic nanostructured compounds are presented :

Hydroxyapatite/collagen nanocomposites

Hybrid nanostructures based on hydroxyapatite/maleic acid copolymers

Hybrid nanostructures based on hydroxyapatite/layered silicate

Hybrid nanostructures based on ZnO/maleic acid copolymers


S (STRENGTH) - O (OPORTUNITIES)

The ability to create crystalline phases which are not stable at the melting point

Materials which have a high vapor pressure near their melting points can be grown by a high pressure method

Suitable for the growth of large good-quality crystals while maintaining good control over their composition

Rapid nanoparticles production, morphology control with a little change of temperature or pressure, control of oxidation state by introducing oxygen or hydrogen gas

By introducing organic substances including biomolecules in a reaction atmosphere of supercriticalhydrothermal / solvothermal synthesis, nanoparticles whose surface is modified with organicmaterials can be synthesized. In supercritical state, water and organic materials form ahomogeneous phase, which provides an excellent reaction atmosphere for the organic modification of nanoparticles

Modification with bio-materials including amino acids is also possible. By changing organic modifiers, particle morphology and crystal structure can be changed. This organic surface modification provides a various unique characteristics for the nanoparticles; possibility to form strength chemical bonding under high pressures conditions between organic-inorganic phases

Dispersion of nanoparticles in aqueous solutions, organic solvents or in liquid polymers can becontrolled by selecting hydrophilic or hydrophobic modifiers

W (WEAKS) – T (THREATS)

Lack of thermodynamic and kinetic data

Very fine powders require high special compacting procedures

SWOT analysis of hydrothermal synthesis


Inorganic salt solution Mineralising agent

Hydrothermal synthesis

Washing/Filtering

Wet powders

Mother liquor/Washing waters

Chemical analysis

Nanocrystalline powders

Solution of doping element

Polymer

UV-VIS, ICP,AAS

XRD, DSC,FT-IR, HRTEM

Structural characterisation

Hydrothermal synthesis of nanostructured compounds


Hydroxyapatite/collagen Hydroxyapatite/collagen nanocompositesnanocomposites

FT-IR analysis of HAp/COL nanocomposites shows the specific bands of hydroxyapatite as well as the presence of collagen with its characteristic functional groups [2].

[2] L.M. Popescu, A. Meghea, R.M. Piticescu, E.Vasile, High pressure synthesis procedure to obtained nanostructured composites for regenerative medicine, submitted to Journal of Optoelectronics and Advanced Materials.

Original results


Hydroxyapatite/collagen Hydroxyapatite/collagen nanocompositesnanocomposites

Hydroxyapatite-collagen hybrid powder consists of particles with spherical or polyhedral shape, grouped in small chains and measuring nearly 4-7 nm in diameter [2].

Nanocrystalline HAp

TEM image of one

representative sample (scale 100

nm)

Original results

[2] L.M. Popescu, A. Meghea, R.M. Piticescu, E.Vasile, High pressure synthesis procedure to obtained nanostructured composites for regenerative medicine, submitted to Journal of Optoelectronics and Advanced Materials.


4500 4000 3500 3000 2500 2000 1500 1000 500

0

10

20

30

40

1992

3571

1411

3434

3631

894

1035

1641

3451

T [

%]

Wavenumber [cm-1]

BVCUAP-purified montmorillonite HBP 4

3635

3224

Roxana Piticescu&al., J. Liquid&Molecular Crystals 2007(In press)

Hybrid nanostructures based on Hybrid nanostructures based on hydroxyapatite/layered silicatehydroxyapatite/layered silicate

Original results


Bright field transmission micrograph of sample HBP2

HRTEM micrograph of sample HBP2

Roxana Piticescu&al., J. Liquid&Molecular Crystals 2007(In press)

Original results

Hybrid nanostructures based on Hybrid nanostructures based on hydroxyapatite/layered silicatehydroxyapatite/layered silicate


Original results

Some preliminary biocompatibility testsSome preliminary biocompatibility tests

SA

SA

SA

SNA

SNA

SA

TiNb/P1HA6S1 TiNb/P1HA6S1

SA

TiNb/P1HA6S2 TiNb/P1HA6S2

SA

SNASNA

SA

TiNb/P1HA6S3

TiNb/P1HA6S3

SA

Citotoxicity tests for TiAlNb alloys coated by spin coating procedure with Phosphorilated polissacharide-Hap nanostructured hybrids

Biocompatibility evaluation of a novel hydroxyapatite-polymer coating for medical implants ( in vitro tests)G.Negroiu, L. Zdrentu R.M. Piticescu ,G. C. Chitanu , I.N. MihailescuAccepted for publication in J.Materials Science: Materials in Medicine


Original results

Hybrid nanostructures based on Hybrid nanostructures based on ZnO/maleic acid copolymerZnO/maleic acid copolymer

Zn(OH)2 - Zinc Hydroxide - 01-074-0094 (I)

ZnO - Zinc Oxide - 01-089-1397 (*)

File: ZnO - AM222.raw

Inte

nsity

(cps

)

0

100

200

300

400

500

2Theta (deg)

20 30 40 50 60 70


Ca10(PO4)6 (OH)2A possible explanation of interactions between natural silicate and HAP

dTRT

Hpd

2ln

Vg > > Vl

Formation of nanocrystalline solid species is favored underhydrothermal conditions

New types of binary systems

Original results


Conclusions

New binary systems based on hydroxyl apatite- purified montmorillonite - were synthesized in situ in hydrothermal conditions at high pressures and low temperatures. The process enables the formation of complex nanostructured materials with controlled phase composition.

The possibility to form chemical bonding between phases was revealed by different methods: XRD, FT-IR

Microstructure and morphology investigation by HRTEM shows the presence of both hydroxyl apatite with rod-like shapes of lengths up to 100 nm and montmorillonite forming a complex nanostructured material.

Further works are in course to detail the mechanisms of formation of the new binary systems.

Further works are in course to analyse and characterise some binary systems synthesised in hydrothermal conditions at very high pressures (3000, 4000, and 7000 bars respectively) at Université de BORDEAUX 1-Centre de Ressources Hautes Pressions (experiments performed in the frame of COST D30 action).


Conclusions

Performed multidisciplinary works try to answer to the ETP Nanomedicine questions:-What are the best materials to be used in regenerative medicine;-What are the appropriate cellular lines ;-Do we need new materials/new technologies;- What is the level of the research in the field of regenerative medicine: basic research and applicative research.


Aknowledgement

This paper is a result of experimental works performed in the frame of Research for Excellence contracts 46-ReteBdent, 69-SINAPS and 16-TECOREMED financed by Romanian Agency for Scientific Research and COST D30 – High pressure Tuning of Materials.

The authors thank:

Prof. Gerard Demazeau - Univ.Bordeaux for fruitfull disscusionsDr.Maria Giurginca - CNC-UPB for performing FT-IR spectra of composites, Dr. Zina Vuluga – ICECHIM for providing natural purified montmorillonite Dr. Gabrielle Chitanu – ICMPP for providing synthetic polymers.Dr. Gabriela Negroiu – Biochemistry Institute, Bucharest, Romanian Academy-for in vitro tests.


Thank you for your attention !

Documents

Functional Nanomaterials II-05.09.2007 New hybrid inorganic-organic nanomaterials obtained in hydrothermal conditions for regenerative medicine Roxana