Former Projects

Adjuvant research is of primary importance in the development of novel and safe vaccines against mutating infectious diseases. Pandemic influenza is a fitting example; in fact, researchers agree that the emergence of a new pandemic strain is not a question of if but a question of where and when. The most efficient way of controlling the rise and spread of a new pandemic disease is through the development of a safe and effective vaccine. Unfortunately, inactivated vaccines alone fail to induce a sufficient immune response and reuqire high doses and multiples administration, increasing vaccine campaign costs and reducing patient compliance. Adjuvants are necessary to ensure a sufficient immunogenicity. There is a need to identify new adjuvants or adjuvant combinations which can be combined with nano-carriers such as polymeric particles to increase targeting and thus reduce toxicity and allow dose sparing. In this study, we characterize and evaluate an adjuvant system composed of tomatine, solanine (lesser known saponins compared to Quillaja saponaria derivatives), SG101 NOD-like receptor (NLR) agonist, synthetized in the University of Ljubljana, encapsulated into PLGA-cholesterol nanoparticles for a WIV H5N1 influenza vaccine.

Project Members :Allegra Peletta, Alcidia Barros Ramos, Dr. Céline Lemoine, Dr. Stéphanie Romand, Dr. Nicolas Collin, Prof. Gerrit Borchard.

Immunotherapy sees its effectiveness limited by the resistance of poorly immunogenic “cold ”tumors, such as found in glioblastoma, prostate can or pancreatic cancer. In order to reduce this resistance, one strategy consists in modifying the tumor microenvironment (TME) towards the “hot ”phenotype, infiltrated by the immune system. Therefore, we used the activation of the stimulator of the interferon gene (STING) of the innate immunity pathway, targeting the cytosol of antigen-presenting cells (APC) in the TME. We opted for cGAMP, a negatively charged STING ligand. To allow targeting of APCs and efficient transfection to the cytosol of APCs (both dendritic cells (DC) and macrophages (M)) as well as protection against enzymes, positively charged carriers are required. For this, we formulated nanoparticles (NPs) with cGAMP through electrostatic interactions. To increase the quality of NP formulations, complementary techniques (DLS, NTA, AF4-MALS, UPLC-UV and EM) were used to characterize NPs ’critical quality attributes (CQA).

Project Members : Dr Marija Petrovic, Dr Olivier Jordan, Prof Gerrit Borchard.

As a multifactorial disease, cancer imposes challenges that have been followed by constant effort by researchers to find new drugs, targets, and therapies. The cocktail combination used in this project was previously identified using the Therapeutically Guided Multidrug Optimization (TGMO) method. A four-drug combination called C2, composed of two tyrosine kinase inhibitors (TKIs): Tacedinaline and Tubacin with two histone deacetylase inhibitors (HDACIs): Erlotinib and Dasatinib was identified as a low-dose drug combination. The efficiency of an optimized drug cocktail is however hindered by distinct pharmacokinetic properties of each drug hence, solubility, polarity, charge, or stability. The result is a lack of control over the ratio, leading to the loss of synergy. Up to the challenge : the use of nanotechnology to load a drug cocktail is a well-known strategy. Indeed, nanoparticles extend drug ’s blood circulation time and allow modulation of time and place of drug release. With their versatility and high biocompatibility, liposomal systems are the nanocarrier this project is based on.

Project Members : Cindy Schelker, Prof Patrycja Nowak-Sliwinska, Prof Gerrit Borchard

During influenza pandemics, the requirement to administer multiple doses of a vaccine to induce immunity is a recognized problem. It would be beneficial to develop vaccine formulations allowing for a single dose of a vaccine to induce immunity equal to what is observed after several immunizations. In this project, poly lactic-co-glycolic acid microparticles (PMPs) are evaluated as an antigen carrier system for H5N1 whole inactivated influenza virus (WIV). For one approach, cationic microparticle formulations have been developed to which the vaccine has been adsorbed and a potent and immediate response is observed in vivo. For a more complex approach, the antigen will be encapsulated to achieve a delayed release. The administration of ‘free’ vaccine combined with encapsulated vaccine into a single-shot formulation should essentially induce a prime and boost immune response.

Protein corona is an important factor in to predict nanomedicines efficacy and safety. Even though the corona has been characterized for different nanosystems, less is known about what happens to proteins at the nano-bio interface. This project aims to predict and optimize the adsorption of a plasma protein to different surface functionalized superparamagnetic iron oxide nanoparticles (SPIONs). Transferrin was chosen as a protein model since it is generally detected on corona. Additionally, studies have shown that selective adsorption of the protein can alter the nanoparticles pharmacodynamics through specific interaction with its receptor. However, the mechanism of transferrin adsorption and potential conformation alterations has not yet been sufficiently examined. We intend to describe and identify the key parameters involved in the nano-bio interface interactions, thus predicting the critical quality attributes (CQAs, i.e. interactions with plasma components) of the nanocarrier system. This will serve as a basis to engineer nanoparticles with a transferrin corona for specifically targeting transferrin receptor 1 (TfR1) expressing endothelia (e.g., the blood-brain barrier), or tumor cells with high metastatic potential.

Project Members : Cíntia Baptista Marques, Dr Olivier Jordan, Prof Gerrit Borchard.

This project deals with novel approaches and combination therapies for the stimulation of immune cells in the liver cancer microenvironment. Vectorization strategies are being developped, using nanoparticles loaded with immunostimulating drug, eventually adsorbed on embolization microspheres. Microspheres with nanoparticles will be delivered through local, intratumoral administration, so called transcatheter arterial embolization (TAE). Besides their mechanical effect during the procedure to stop the blood flow, beads also release nanoparticles, letting the tumor soaked in a high concentration of drug, therefore activating the immune response. Such an approahc intends should improve treatment efficacy and reduce side effects.

Our strategy is based on an iterative optimization including a computational approach to understand the interaction of polymeric biomaterials and small interfering RiboNucleic Acids (siRNA), and their physicochemical and biophysical characterization. An ideal number of amino groups in combination with a typical siRNA entity is investigated. The molecular dynamics simulations suggested by Prof. Danani (SUPSI) determine precision polycations with accurate characteristics for an optimal loading and delivery of nucleic acids. The resulting benefit of these predictions is to rapidly develop a novel delivery system with reduced cytotoxicity.

The initial phase of the project is to PEGylate selected cationic polymers, followed by the synthesis of biocompatible and biodegradable polymers to form triblock co-polymers. These biomaterials form micellar systems (nanocarriers) by self-assembly, which are fully characterized and tested on cells successively to evaluate the safety of the polymer candidates. After formulation with siRNA, micelles’ internalization is tracked by microscopic methods. Knockdown mechanisms are further investigated for a proof of silencing efficiency.

More information on the computer modelling part : http://m3.dti.supsi.ch/index.php/projects/4584-2/

Among numerous biomedical applications of superparamagnetic iron oxide nanoparticles (SPIONs), we are studying their potential as MRI contrast agent in the detection of early lymph node metastases of prostate cancer. Aptamer ligands targeting the prostate-specific membrane antigen (PSMA) are attached to coated SPIONs and optimized for lymph node delivery to investigate their specificity towards prostate cancer cells. Another promising use of SPIONs called magnetic-induced hyperthermia relies on SPIONs ability to release heat when exposed to an alternating magnetic field. Localized hyperthermia sensitizes tumor tissue to radio- or chemotherapy and can even destroy these tissues. However, reaching the target temperature for moderate hyperthermia (42 – 45 °C) under clinically acceptable magnetic field strengths and frequencies remains a challenge. We are currently developing a liquid polymer formulation containing SPIONs optimized for hyperthermia. Solidifying as a compact, radiopaque implant entrapping SPIONs upon injection in biological tissue, the implant reaches its target temperatures at low magnetic field strengths and frequencies.

Absorption of drugs is a constant and recurrent problem in drug design, especially with the gastro-intestinal metabolism before the absorption. The nasal route is not already used at its complete capacities even if it’s one of the part of the body where the blood flow is the most important. By this way we could be able to avoid the metabolism of drugs before absorption. In our lab we synthesized a peptide which can open reversibly and temporarily the tight junctions. The objective is to find some application for this peptide by some permeability experiments. Several ideas came to use this peptide, like mixing it with naloxone. The intention in the end is to be able to cure opioid crisis in emergency.

Iron sucrose (IS) is a highly complex colloidal suspension used to treat iron deficiency anemia. Addressing the problems of quality, safety and efficacy within IS and its follow-on versions (ISSs), regulatory agencies recently underlined the need of new assays to characterize these drugs. In this perspective, innovative analytical methods for the physicochemical characterization of IS and several ISSs were developed, retrieving statistically significant differences. These specifically tailored assays might serve as tools for the establishment of IS’s critical quality attributes by regulatory agencies as well as tools for the evaluation of degree of similarity between IS and ISSs and they represent the first example of an orthogonal characterization approach in the framework of NBCDs. Moreover, the need of specific multimethod strategies for characterizing iron polymaltose complex, as another example of nanomedicines to contrast anemia, was emphasized.

More examples on the old website http://www.unige.ch/sciences/pharm/fabio/itemcomp_en.html

The re-epithelialization step during wound healing is an essential step to protect the underlying tissue from infectious agents and from extensive water loss. In case of non-healing wounds, this step might be impaired and proliferation- and migration promoting strategies may offer an attractive solution. In this view, we developed different formulations for topical application, based on carboxymethylated chitosan (CMTMC) displaying Arg-Gly-Asp (RGD) peptide. RGD, a known bioadhesion peptide, was thus anchored to the chitosan matrix in order to better interact with the cells. The peptide-functionalized gel, foams and nanoparticles were shown to promote cell adhesion and migration.

Controlled delivery of biologicals without losing their activity is an everlasting challenge. Efforts are made to design and evaluate a reliable system that can meet this challenge via adapting the concepts of Layer By Layer (LBL) Technology in 2 main themes: a. Sustained delivery of injectable active peptides b. Development of LBL nanoparticles coated with viral proteins as a novel intracellular delivery system.

Localized mild hyperthermia sensitizes tumoral tissues to radio- or chemotherapy, and can even destroy these tissues. We developed formulations that, once injected intratumorally, form an implant carrying superparamagnetic nanoparticles and anticancer agents. The implant can be heated applying an external magnetic field, sensitizing the surrounding tumoral tissues, while releasing the chemotherapeutic agent. By combining hyperthermia and chemotherapy, a synergetic effect could be reached improving the therapeutic effects of the implant.

Common treatment for arthritis or osteoarthritis, intra-articularly injected steroid suspensions are not exempt of undesired effects, such as poor retention in the joint or appearance of crystal-induced pain. To overcome these limitations, we propose PLGA microparticles co-encapsulating the anti-inflammatory drug dexamethasone acetate and Superparamagnetic Iron Oxide Nanoparticles (SPIONs) as intra-articular drug delivery systems. Embedded in the microparticle polymer matrix, the corticosteroid is gradually released, thus avoiding crystal formation in the joint. Moreover, due to the magnetic nature of SPIONs, the microparticles could be retained in the joint with an external magnet, thus reducing their clearance from the joint.

Endoscopic injection of bulking agents under urethral mucosa is an effective but short-lasting treatment of stress urinary incontinence. Biomaterials for a durable recovery of continence are still needed. For this purpose, we are evaluating precipitating polymeric formulations, hydrogels and microspheres suspensions

Cerebral aneurysms and vascular malformations are prevalent life-threatening conditions. Prevention of hemorragic rupture may be achieved through endovascular embolization with polymers. For this purpose, we developed radiopaque injectable biomaterials and shown their ability to embolize aneurysms.

Mucosal vaccination is a real challenge to induce protective immunity against mucosal pathogens, but successes (oral Polio vaccine, nasal-spray Flu vaccine) are moderated by failed attempts (HIV, mycobacterium). Synthetic biodegradable particles have been widely used for vaccine application; however their immunostimulator effect on immune cells is often weak. To increase potency and specificity of mucosal immune responses, additional immunostimulatory signals, such as TLR agonists, could be delivered together with the antigens. We developed biodegradable nanocarrier systems loaded with multiple TLR agonists: incorporated (imiquimod for the intracellular TLR7) and/or decorated (Pam3Cys for the cell surface TLR2) on the PLGA particles.

The potential of mucosal immunization in humans has been recognised and investigated over the last decades. However, the requirement of efficient and safe carrier systems for antigen subunits remains the biggest challenge in mucosal vaccination. Therefore, this project investigates the development and the in vitro and in vivo characterization of such vaccines, at various sites of administration.

In the present project the physical stability of protein formulations is investigated. Several new excipients are synthesized and tested for their ability to ameliorate or even inhibit non-native aggregation of proteins under solution conditions to prolong their stability during formulation, shipping and storage

Within the scope of our research project, we are focusing on the optimization of chitosan as delivery system for pulmonary vaccination. Hereby, we one aim is to improve the adjuvanticity of chitosan materials, which could be possibly achieved by functionalization with mucosal adjuvants. Among potential compounds, so-called Toll-like receptor (TLR) agonists attracted drew much attention. Therefore, we are aiming at covalent binding of different TLR agonists to modified chitosan in order to enhance its adjuvanticity as delivery system for mucosal vaccination.

Hepatic carcinoma might be treated by infusion of beads into the tumor vasculature - so - called embolization - leading to tumor death. Drug-eluting beads delivering locally an anticancer agent may avoid adverse effects and improve the efficiency of the treatment.

The conjugation of a polyethylene Glycol (PEG) polymer to a protein drug can have many advantages; an enhanced stability in vitro, reduced immunogenicity, enhanced stability against enzymatic destruction, reduced renal clearance and enhanced solubility. The receptor affinity of the protein drug is, however, reduced as well. We are trying to design novel PEG-based excipients which are being non-covalently bound to a therapeutic protein in order to imbue the drug with many of the desired effects of PEGylation but keeping its native receptor affinity.