Project leaders: Claire Monge (CR), Thomas Trimaille (MCU)
Participants: Sofia Caridade (Post-Doc), Anne-Lise Paris (PhD student, ANRS), Damien Ficheux (IE), Evelyne Colomb (IE).
Objective 1: Biodegradable nano-assemblies based on PLA backbone
On the basis on our solid expertise on versatile PLA-based nanoparticles/micelles, we aim at pursuing our efforts in the development of improved functional nano-delivery systems, with a particular emphasis on three issues:
• Design of fluorescent nanoparticles for monitoring NP trafficking in vivo and ex vivo, using whole cell imaging techniques. For instance, we master the synthesis of PLA particles with hydrophobic fluorophores (coumarin6, Dir, etc..) which permits to monitor their in vivo trafficking.
Distribution of infra-red fluorescent particles 24h after their administration by sub-cutaneous, intra-tracheal or intra-nasal route. The white arrows point the injection sites. Those images highlight the particles accumulation within the secondary lymphoid structures after their administration in mice, analysis performed by fluorescent tomography (FMT 4000).
• Triggered vaccine/drug release, with the development of micelles able to release encapsulated biomolecules upon stimuli. For instance, we develop micelles based on PLA backbone able to carry either proteins moities or mRNAsuch as NIR/UV irradiation or to carry nucleic acids.
Schematical representation of the micellar nanoparticles developed as vaccine adjuvants; (A) polymeric micelles obtained by self-assembly of amphiphilic block copolymers in water, in/on which the antigenic peptide is encapsulated (1) or surface coupled (2) (reactive groups represented by star symbols); (B) micelles obtained from self-assembly of peptide antigen amphiphiles in water. D’apres Jimenez-Sanchez et al, Pharm Res. 2015,32 (1)311-20
• Oral delivery : with the development of various coating strategies of NPs, such as pH sensitive for by-passing gastrointestinal environment or maintaining colloidal stability for nebulization. For instance, we are comparing micelles and PLA nanoparticles for pulmonary delivery of antibiotics or nucleic acids using whole body imaging and intratracheal administration.
Objective 2: Dual delivery system using PLA and nanofibers scaffold or hydrogels
Emerging evidences show that combination of therapeutic approaches in one single implantable system is currently the most promising approach to gain therapeutic efficiency. Therefore, based on our PLA-NP expertise, we are pursuing this objective by:
• Designing scaffolds of biodegradable nanofibers, mimicking the extracellular matrix
Our strategy is particularly developed in the context of wound healing, with the aim of providing optimal environment for tissue ingrowth. In case of skin wound healing, (ANR Astrid) we particularly focus on nanofibrous PLA/PLGA scaffolds (oriented or not) created by the jet-spraying technique (collaboration with D. Sigaudo-Roussel, J. Sohier), associated with PLA-NPs functionalized with various biomolecules of interest (antibiotics, anti-oxydant, growth factors).
Schematic illustration of the different strategies followed to associate nanoparticles and microfibers
and SEM micrographs at various magnifications of MF-NP edifices obtained by co-projection of NP during jet-spraying of PLGA (A) and PLA (B) MF d’après Keloglu N, et al, 2016Colloids Surf B Biointerfaces. 2016 Apr 1;140:142-9.
• Designing topical formulations based on biocompatible hydrogel with embedded nanoparticles
This strategy is dedicated to topical delivery of active ingredients, such ingredients being either included in the gel or loaded in the core of NPs. For instance, in case of a skin disorder (psoriasis), we focus on the design of hydrogel containing nanoparticles, with a strong emphasis on using biocompatible hydrogel for topical administration. The main challenge we face is to maintain the colloidal behavior of nanoparticles after their embedding in such hydrogels.
Objective 3: Polyelectrolyte multilayer films as drug delivery systems
The controlled delivery of drugs is one of the main challenges in pharmaco-biology. Our response is the development of a membrane able to deliver bioactive molecules with a spatial and temporal control of their release.
The Layer-by-Layer (LbL) technology is used to build free-standing (FS) films made of successive deposition of a polycation (PC) and a polyanion (PA). We aim at using natural polymers and green chemistry in the production of our delivery systems; no solvents are used in the process and the final membranes are fully biodegradable and biocompatible.
Layer by layer FS membrane build-up. A polycation (PC) and a polyanion (PA) are successively deposited on a polypropylene (PP) substrate. After air drying, the membrane can be manipulated easily.
These LbL assemblies can be loaded with a variety of molecules (cytokines, nucleic acids, growth factors…) [Monge et al, Adv Healthc Mat, 2015]. The amount and level of bioactive molecule incorporation, the degree of crosslinking or the size of the polymers allow the control of the temporal release of the incorporated molecule. The confinement of the drugs inside the core of the membrane ensures their topical delivery. The FS membranes are a versatile tool, adaptable to either chemotherapeutic treatments or tissue engineering, and are easily implantable in vivo.
Selection of publications:
Berthet M, Gauthier Y, Lacroix C, Verrier B, Monge C. (2017) Nanoparticle-Based Dressing: The Future of Wound Treatment? Trends Biotechnol. 35(8):770-784.
Jiménez-Sánchez G, Terrat C, Verrier B, Gigmes D, Trimaille T. (2017) Improving bioassay sensitivity through immobilization of bio-probes onto reactive micelles. Chem Commun (Camb). 2017 Jul 13;53(57):8062-8065.
Gutjahr A, Phelip C, Coolen AL, Monge C, Boisgard AS, Paul S, Verrier B. (2016) Biodegradable Polymeric Nanoparticle-based vaccine adjuvants for lymph nodes targeting. Vaccines (Basel). 2016 Oct 12;4(4).
Monge C, Almodóvar J, Boudou T, Picart C. (2015) Spatio-Temporal Control of LbL Films for Biomedical Applications: From 2D to 3D. Adv Healthc Mater. 4(6):811-30.
Trimaille T, Verrier B. (2015) Micelle-Based Adjuvants for Subunit Vaccine Delivery. Vaccines (Basel). 3(4):803-13.
Caridade SG, Monge C, Almodóvar J, Guillot R, Lavaud J, Josserand V, Coll JL, Mano JF, Picart C. (2015) Myoconductive and osteoinductive free-standing polysaccharide membranes. Acta Biomater. 15:139-49.
Caridade SG, Monge C, Gilde F, Boudou T, Mano JF, Picart C. (2013) Free-standing polyelectrolyte membranes made of chitosan and alginate. Biomacromolecules. 2013 May 13;14(5):1653-60.
Inter groups collaborations: D. Sigaudo-Roussel, J. Sohier, F. Pirot.
Grants: Astrid 2015-2018, Marie curie fellowhip, Sidaction, ANRS, Eranet Flunanoair.