Electrospinning and Nanofabrication for Health and Energy

Resp. Pr. Guy Schlatter, Dr. Anne Hébraud, Dr. Emeline Lobry

For more details, see our publications

• Equipements disponibles à l'ICPEES
• 2D and 3D assemblies / Nanofibers for health
• Supramolecular materials: from the structures and the self-assembling properties to the processing
• Functional nanofibers for energy, catalysis and sensors
• Funders and industrial partners
• Competitiveness clusters and federation

Nanofibers and microparticles celebrating 100 years of ECPM! Picture obtained by scanning electron microscopy and then colored. 

Electrospinning is a process allowing the elaboration of nanofibrous non-woven membranes (fiber diameter ≈ 50 nm up to 1 μm) from polymer solutions or molten polymers. We develop novel processes in order to control the structures at the scale of the nanofiber as well as at the scale of the membrane. Thanks to collaborations, the elaborated materials can be used for biomedical applications, sensors, catalysis or filters.

Equipements disponibles à l'ICPEES

L'équipe de l'ICPEES a développé une plateforme d'electrospinning unique composée de 4 systèmes dont 1 à l’échelle pilote :

- Système ES1 : système home-made permettant l'electrospinning sur collecteur statique avec possibilité de travailler en voie electrospinning réactif par photochimie.

- Système ES3 : équipement disposant d'un collecteur rotatif vertical permettant de travailler avec 4 émetteurs à aiguilles pour l'élaboration de membranes composites multifibres. Le collecteur peut tourner à très haute vitesse pour induire l'alignement mécanique des nanofibres.

- Système ES4 : équipement disposant d'un collecteur rotatif horizontal permettant de travailler avec 2 émetteurs à aiguilles ou encore des émetteurs sans aiguille pour la production rapide d'échantillons allant jusqu'à 20x30 cm2.

- Système NS-LAB Elmarco© : Le système est représentatif des dispositifs de production industriels Elmarco© et permet la production en continu sur des support de 50cm de large et de longueur quelconque. Le système est équipé d'une caméra haute vitesse permettant de filmer les jets d'electrospinning.

2D and 3D assemblies / Nanofibers for health

We seek to control the organization of the nanofibers in the final material. This microstructuration allows the control of the porosity, the anisotropy of the fiber deposit (aligned fibers, stars,...) or even the chemical composition at the scale of few tens of microns. It will allow to open new applications (tissue engineering, composites, sensors,...). Some of these strategies were or are developped under the frame of ANR projects (ANR-P2N-2011-NeoTissage and ANR-DS03-2015-MimHeart).

The main collaborations  are established with INSERM allowing us to envisage several applications for tissue engineering or wound healing. We also develop different strategies to functionalize the surface of the nanofibers such as the grafting of peptides on polyrotaxane-based fibers (Project ANR-blanc 2011 FibRotaxanes) or thanks to the elaboration of coaxial fibers by the incorporation of drugs in the shell formulation (project in collaboration with UFSCAR, Sao Carlos, Brazil).

2D structures obtained thanks to the use of micro-patterned collectors. Ref: N. Lavielle et al. "Structuring and molding of electrospun nanofibers: Effect of electrical and topographical local properties of micro-patterned collectors ", Macromolecular Materials and Engineering, vol. 297, pp. 958-968, 2012. Link

Micro-structured honeycomb nanofibrous scaffolds. Effect of the structuration on the proliferation of bone cells (collaboration with INSERM-U1109). Ref: S. Nedjari, S. Eap, A. Hébraud, C.R. Wittmer, N. Benkirane-Jessel, G. Schlatter, "Electrospun Honeycomb as Nests for Osteoblast Proliferation", Macromolecular Bioscience, vol. 14, pp. 1580-1589, 2014. Link

From self-assembled nanofibers to 3D porous cm-thick constructs: application for bone regeneration. Ref: D. Ahirwal et al. "From Self-assembly of Electrospun NanoFibers to 3D cm-thick Hierarchical Foams", Soft Matter, vol. 9(11), pp. 3164-3172, 2013. Link

3D structured composites made of nanofibres and microparticules obtained by ETAD process allowing controlled electrostatic interactions during alternate electrospinning and electrospraying on micro patterned collectors. Ref: C.R. Wittmer, A. Hébraud, S. Nedjari, G. Schlatter, "Well-Organized 3D Nanofibrous Composite Constructs using Cooperative Effects between Electrospinning and Electrospraying", Polymer, vol. 55, pp. 5781-5787, 2014. Link Application of the process for the elaboration of biomimetic scaffolds for bone tissue engineering. Ref: A. Garcia Garcia et al, "Poly(e-caprolactone) / hydroxyapatite 3D honeycomb scaffolds for a cellular microenvironment adapted to maxillofacial-bone reconstruction", ACS Biomaterials Science and Engineering, vol. 4, pp. 3317–3326, 2018. Link

3D structures with controlled porosity gradient obtained by electrospinning on micropatterned collectors. a) Cross-section (x,z plane) of the membrane showing the porosity gradient. b) (x,y) planes obtained from X-ray micro-tomography for different z values. c,d) Mechanisms of the 3D structuration. Ref: S. Nedjari, G. Schlatter, A. Hébraud, "Thick Honeycomb Electrospun Scaffold with Controlled Pore Size and Porosity Gradient", Materials Letters, vol. 142, pp. 180-183, 2015. Link

Coaxial structure (PCL/gelatin/hydroxyapatite) of nanofibers for bone regeneration (collaboration with UFSCAR, Sao Carlos, Brazil). Ref: I.H.L. Pereira, E. Ayres, L. Averous, G. Schlatter, A. Hébraud, A.C. Chagas de Paula, P. Henrique L. Viana, A.M. Goes, R.L. Oréfice, "Differentiation of human adipose-derived stem cells seeded on mineralized electrospun co-axial poly(caprolactone) (PCL) / gelatin nanofibers", Journal of Materials Science: Materials in Medicine, vol. 25, pp. 1137-1148, 2014. Link

 

 

Supramolecular materials: from the structures and the self-assembling properties to the processing

Cyclodextrin-based materials:

Polyrotaxanes (PR) are supramolecular necklaces used for the elaboration of functional materials or supramolecular gels with high mechanical properties and high swelling ratio. We focus on the synthesis of PR based on cyclodextrines (ring molecules of the necklace with 6, 7 or 8 glucose units) and polymers (forming the chain of the necklace) such as polyethylene oxyde (PEO), polypropylene oxyde (PPO), PEO-PPO-PEO block copolymers or poly(ε-caprolactone). We also focus on the self-assembling properties of PR and pseudo-PR and on their application for biomedical (project ANR-Blanc FibRotaxanes 2011-2014).
Furthermore, cyclodextrins are also used in the formulations for electrospinning in order to functionalize the nanofibers for drug encapsulation and controlled release purposes. Cyclodextrin is also a processing aid for electrospinning in aqueous solution.

Tannic acid based materials:

More recently, we started research activities dealing with the elaboration of materials from tannic acid, a molecule allowing the formation of supramolecular assemblies through either hydrogen or ionic bonds with polymers or indirectly through coordinate bonds with metals.

We demonstrated that electrospinning of tannic acid in water without any polymer is possible thanks to the formation of a supramolecular network in the processed solution. Subsequently, the nanowebs can be efficiently cross-linked in water either by oxidative reaction with sodium periodate or, most interestingly, with Fe(III) by a combination of oxidative reaction and the formation of coordination complexes. The proposed strategy is easy, low cost, scalable and uses non-toxic solvents as well as biocompatible and biofunctional molecules paving thus the way for various applications in material and biomaterial sciences as well as in catalysis. Ref: M. Allais, D. Mailley et al. "Polymer-free electrospinning of tannic acid and cross-linking in water for hybrid supramolecular nanofibres", Nanoscale, vol. 10, pp. 9164-9173, 2018. Link.

Nano-platelets of pseudo-polyrotaxanes based on β-CD and pluronics. Ref: C. Perry et al. "Pluronic and β-cyclodextrin in water: from swollen micelles to self-assembled crystalline platelets", Soft Matter, vol. 7, pp. 3502-3512, 2011. Link

Functional nanofibers for energy, catalysis and sensors

The goal of this research axis is the preparation and the characterization of functional organic, inorganic or hybrid nanofibers for energy, catalysis or sensors. Our approach starts from the chemistry (synthesis of semi-conductive conjugated polymers, sol-gel processes,...) to the elaboration and the characterization of devices (organic field effect transistors (OFET), sensors...) thanks to the available equipments (STnano clean room, organic electronics platform at team MaCÉPV from Icube and well-established collaborations with other teams of ICPEES. Thus, we are working on the fabrication of sensors made of composite nanofibers, the elaboration of TiO₂-based photocatalytic nanofibrous materials (collaboration with the Department "Catalyse, Energie et Procédés" team: Photocatalyse et Photoconversion), carbon-based nanofibers (Department "Physico-Chimie des Nanosystèmes" team: Nanomatériaux, Catalyse et Interfaces) or the fabrication of membranes for fuel cells (PMNA-Région Alsace project supervised by the Electrochimie et Conversion d'Energie team of the "Catalyse, Energie et Procédés" Department).

Funders and industrial partners

Competitiveness clusters and federation