Processable intelligEnt Colloids for MucoSal Drug Delivery – PECSDDeli

The project aims at developing a mucosal drug delivery nano system simple to administer and to manufacture, based on safe, biodegradable and biocompatible polysaccharides. So the two major objectives of this project are :
i) to design a green and scalable process of manufacturing colloidal delivery systems using no toxic chemicals nor solvent and based on two polysaccharides renown for their safety,
ii) to develop a simple targeting strategy based on humanized monoclonal antibodies aiming at the natural reservoirs of the HIV virus which is our model to perform the feasibility of the concept.
The elaboration of the nanoassemblies will take place as follows:
- synthesis of colloidal PECs of chitosan and dextran sulfate with the objective of developing a sound, environmental friendly and acceptable by the regulatory agencies, process of manufacturing these nanoassemblies of natural products. These colloidal PECs should meet the following requirements : submicrometric size, stable in physiological medium, modular surface charge, loading capacity of low molar mass drugs and macromolecular targeting species;
- incorporation of drugs or fluorescent dye in the carriers, using both PLA particles as model colloids and the colloidal PECs. The loading of colloidal PECs with the drugs will be carried out by IMP in collaboration with IBCP. Two model drugs will be considered : hydrophilic Emtricitabine (FTC) and hydrophobic Efavirenz.
- surface functionalisation with the targeting antibodies provided by partner 4 and intended to fuel WP 4 & 5. Partners 1 & 2 involved in this task have already worked together in this field and so they have an outstanding experience in the adsorption of various proteins onto colloids such as PLA particles or colloidal PECs. The determination of the parameters that control the binding process as a function of the nature of the antibodies and the physico-chemical properties of the colloidal interface (surface charge, hydrophobicity, structural organization) will provide a sound understanding of the functionalisation process, a means to secure and provide robustness to the production process.

The targeting strategy of the natural reservoirs of HIV will be implemented as follows:
- elaboration and production of two human IgA monoclonals one directed against HIV glycoprotein (gp41 part of gp160), the other one against a natural receptor expressed on potential HIV reservoirs, a4ß7 integrin. The production technology is proprietary of the SME, B Cell Design. To obtain high affinity monoclonals to ensure the success of the targeting purpose, the adjuvant capacity of PLAs nanoparticles will be used via the other SME partner Phusis.
- selection of nanoassembly candidates will be carried out first according to a multi step process: 1) using a model cell monolayer containing M cells to screen the formulations of crossing a simple monolayer; 2) the mouse ligated loop model, that maintains the natural homeostasis of the intestinal mucosa, to provide improved data on the migrating capacity of each formulation; 3) use of a mouse model after oral or enteric administration to monitor the specific uptake of nanoassemblies in the presence of the natural acidic environment and intestinal mucus thanks to the Cell Vizio imaging technique; 4) use of cynolmogus macaques for the final selection of nanoassemblies candidate by sampling intestine biopsies and confocal analysis co-localization.
- evaluation of the specific targeting of HIV infected cell by the nanoassemblies screened above i) first, in vitro on HIV-1 infected cells ii) second, on SHIV infected cynomolgus, after enteric administration and monitored by imagery tools. The final objective is to demonstrate the feasibility of our targeting strategy for addressing in dedicated cells significant amount of ARD through the mucosal administration of smart nanosystems.