The "APGI YOUNG INVESTIGATOR AWARD" (sponsored by Sanofi and delivered jointly by SANOFI and APGI) recognizes the most outstanding doctoral thesis in the field of Pharmaceutical Technology each year .
If you defended your PhD thesis between 15 November 2016 and 14 November 2017, you can candidate for the 2016 "APGI YOUNG INVESTIGATOR AWARD".
Please send a pdf file of your thesis (in French or English) and a short curriculum vitae, by 24 November 2017, to APGI (firstname.lastname@example.org) and
Thanks to the supervisors to forward this information to potentially interested former PhD students.
The price (accompanied by a check) will be officially awarded at the 11th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology (from 19 March to 22 March 2018) in Granada, Spain.
The « APGI YOUNG INVESTIGATOR AWARD" sponsored by Sanofi grants each year a doctoral thesis completed in Drug delivery Science. The award (with a check) is given during an APGI meeting.
You will learn soon about the award to be given in 2017.
APGI thesis award 2016/2017
Dr Stephan STREMERSCH
Laboratory for General Biochemistry and Physical Pharmacy,
Faculty of Pharmaceutical Sciences, Ghent University
Promoters: Prof. S. De Smedt, Prof. K. Raemdonck, Prof. K. Braeckmans
has been awarded for his Ph.D. thesis entitled:
"Exploring extracellular vesicles for siRNA delivery and Raman-based diagnostics"
In this thesis the ability of EVs to functionally deliver small interfering RNA (siRNA) was explored. Despite some interesting earlier reports in the literature on the value of EVs as bio-inspired drug carriers, many fundamental biological questions, pertaining to the EV biodistribution, cell uptake specificity and cargo release, remain largely unanswered to date. Additionally, technical hurdles such as inadequate purification strategies and the lack of an efficient loading strategy for macromolecular therapeutics should be overcome to reliably assess the true advantage EVs might have over current state-of-the-art delivery strategies (e.g. liposomes and viral vectors).
A first step in pursuit of harnessing EVs for siRNA delivery is the development of a method to obtain purified vesicles. It is important to realize that EVs represent only a fraction of the cell’s secretome. Different methods to isolate and purify EVs out of conditioned cell medium and biological fluids have been suggested. These approaches rely on the EV’s typical size, density, solubility, surface components or a combination of the above. Currently, no consensus on a gold standard protocol exists, which hampers unambiguous comparison of different studies and increases the risk of misconceptions due to residual impurities when using insufficiently stringent purification protocols. In chapter 3 a number of commonly used techniques to purify EVs from endogenous (e.g.protein complexes) and exogenous (e.g. fluorescent dyes) components were compared. Protocols based on a density gradient and size-exclusion chromatography outperformed differential centrifugation- and precipitation-based approaches. In combination with a better understanding of the influence of the respective isolation procedures on the EV functionality, these observations can contribute to the implementation of a more standardized purification protocol.
The shortcomings of electroporation and the current lack of alternatives to load hydrophilic macromolecules into EVs prompted us to explore new approaches. In chapter 4 we developed a generally applicable method to attach siRNA to the surface of isolated EVs by means of a cholesterol anchor. Moreover, given the complexity and heterogeneity of EV isolates and the previously described loading artifacts with electroporation, here we used a combination of three complementary assays to confirm and quantify siRNA loading (i.e. a gel retention assay, an antibody capture assay and a density gradient co-localization assay). As this approach was also able to load pre- formed liposomes with siRNA with comparable efficiency, a direct comparison between EVs and synthetic liposomes with regard to siRNA delivery could be made. To this end, we selected negatively charged, fusogenic liposomes with a size distribution comparable to EVs. Unfortunately, under the tested in vitro conditions, EVs underperformed compared to the liposomes for their ability to functionally deliver the siRNA therapeutic, which could be attributed to the lack of an intrinsic mechanism to induce endosomal escape prior to trafficking to lysosomes for degradation. Likewise, the endogenously present miRNAs were not functionally delivered to recipient cells. These observations question the efficiency and universal applicability of EVs as a gene therapy nanocarrier.
In conclusion, in a first part of this dissertation the potential of EVs as a drug delivery carrier for siRNA was assessed. We could obtain pure EVs by means of a density gradient purification protocol and load them by exploiting the hydrophobic interaction between the EV membrane and a cholesterol tag covalently attached to one of the siRNA strands. However, under the experimental conditions EVs were unable to bypass the endolysosomal degradation pathway and hence were unable to functionally deliver siRNA upon cellular internalization. To a certain extent, our observations temper the high expectations linked to exploiting EVs as a drug delivery carrier and call for a more in-depth biological understanding of the EV’s cellular delivery mechanism and related cell type specificity. Nonetheless, other therapeutic applications of EVs, as discussed in chapter 6, are very promising and are already developed up to market level (e.g. EV- based immunotherapy). In the second part of this dissertation, we developed a new nanotechnological platform that allows the fast characterization of individual EVs via surface enhanced Raman spectroscopy. As EVs are very promising biomarkers, the high sensitivity inherent to the developed technology makes this an attractive platform to explore further in a diagnostic setting.
APGI thesis award 2015/2016
Dr Alice GAUDIN
UMR CNRS 8612
University of Paris-Sud
School of Pharmacy
Promoters: Prof. P. Couvreur and Prof. K. Andrieux
has been awarded for her Ph.D. thesis entitled:
« Squalenoyl Adenosine Nanoparticles and Cerebral Ischemia: evaluation of the passage of the Blood-Brain Barrier, pharmacological efficiency and theranostic »
This PhD work, as a part of the ERC Advanced Grant project «TERNANOMED», aimed at developing a squalenoyl nanomedicine of adenosine (SQAd NAs), for the treatment of stroke and spinal cord injury (SCI). The ﬁrst part of this research was dedicated to the preparation and characterization of SQAd NAs, and highlighted their dramatic therapeutic activity in pre-clinical models of cerebral ischemia and SCI. To further understand the mechanism of action of these NAs, the second part of this thesis was devoted to the detailed study of their transcytosis across the Blood- Brain Barrier. It was shown that the NAs were disassembled inside the endothelial cells, conﬁrming that the pharmacological mechanism of the SQAd NAs action appeared to be a primary vascular protection via the improvement of microcirculation, leading to a secondary neuronal preservation, likely thanks to neurovascular coupling and to the pleiotropic multitargeted abilities of adenosine. The third part of this work aimed to describe the pharmacokinetic proﬁle and issue distribution of SQAd NAs, thanks to innovative techniques of radiolabeling. Finally, the fourth part presented preliminary results on the development of a theranostic tool, by incorporating USPIO as a MRI contrast agent inside the SQAd NAs. Overall, this PhD work established the foundation to the extension of the squalenoylation platform to the treatment of neurological diseases.
Keywords: nanomedicine, squalene, adenosine, stroke, spinal cord injury, blood-brain barrier