# Steering the Clinical Translation of Delivery Systems for Drugs and Health Products
## 3 Poster Presentations
### Polysaccharide Hydrogels for the Stabilization and Controlled Release of Ionic Cargo
###### Abstract  
In this paper, we present a novel core-shell structure nanohydrogel system based on the biolatronic acid (HA-SH) and vinyl sulfonated poly(HPMAm-lac\({}_{1}\)-2)-PEG-poly(HPMAm-lac\({}_{1,2}\)) triblock copolymer (Trib-sulfur) was developed as a carrier for prostate-specific oncolytic adenovirus Ad Ad[I/PPT-E1A]. After the synthesis of Trib-sulfur and HA-SH polymer, [36] nanocapsules were prepared by the W/O emulsion method. HA-SH was dissolved in Ad[I/PPT-E1A] PBS as water phase, while Trib-sulfur was dissolved in CHCl\({}_{3}\) supplemented with lecithin (5.0% w/v). The water phase was added dropwise into organic phase and homogenized at 4 \({}^{\circ}\)C. The emulsion was kept at 4 \({}^{\circ}\)C overnight under gentle stirring, and then purified by washing with chloroform to remove residual lecithin. A novel adenovirus delivery system was successfully developed composed by a HA-SH core and Trib-sulfur shell. The particle size ranged from 439.6 and 387.9 nm for empty and Ad-loaded nanohydrogel, respectively. The zeta potential was negative -38.19 and 31.85 mV, for empty and Ad-loaded nanohydrogel, respectively. The morphology of nanohydrogel was observed by SEM and TEM. It can be seen the nanohydrogel has a smooth surface and core-shell structure. According to the TEM pictures, it can be visually observed the encapsulation of adenovirus into the nanohydrogel. The toxicity of nanohydrogel and adenovirus activity after encapsulation were measured by MTT assay on PC3 prostate cancer cells. The MTT assay showed the adenovirus can still successfully infect the prostate cancer cells after encapsulation. In conclusion, in this work, we demonstrated the suitability of the developed HA-SH/Trib-sulfur core-shell structure nanohydrogel as delivery system for oncolytic adenovirus. To conclude, we demonstrated that the described nanohydrogel system has interesting biofunctional properties and high versatility of processing, being able to be prepared as nano-scaled delivery system for other kinds of oncolytic adenovirus and also other immune compounds in order to contribute to cancer immunotherapy. **Acknowledgments:** The authors acknowledge receipt of a European Commission funded H2020 MSCA-ETN grant under proposal number 675743 (project acronym: ISPIC). **Conflicts of Interest:** The authors declare no conflict of interest. Extracellular Vesicles as Delivery Carriers of Oncolytic Viruses and Therapeutic Agents for Mesothelioma Treatment  
[PERSON] \({}^{1,2}\), [PERSON] \({}^{3}\), [PERSON] \({}^{4}\), [PERSON] \({}^{4}\), [PERSON] \({}^{4}\) and [PERSON] \({}^{4,*}\)  
\({}^{1}\) Targovax Oy, Clinical Science, 00180 Helsinki, Finland  
\({}^{2}\) Department of Virology, National Institute of Public Health--National Institute of Hygiene, 00-791 Warsaw, Poland  
\({}^{3}\) Core Facility Alternative Biomodels and Pre-clinical Imaging, Medical University of Graz, Biomedical Research, 8010 Graz, Austria  
\({}^{4}\) Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35122 Padua, Italy  
\({}^{*}\) Correspondence: [EMAIL_ADDRESS] remarkable improvements achieved in cancer treatment modalities, the outcome remains partially ineffective against different cancer types such as malignant pleural mesothelioma (MPM). Therefore, new and most effective treatment modalities are in high demand. The use of oncolytic viruses (OVs), able to selectively infect, replicate in and induce antitumor immune responses is one of the most promising approaches currently investigated worldwide. Although promising efficacy was observed in pre-clinical and clinical studies, OVs are often administered intra-lumorally (i.t. ), thus many solid tumors cannot be treated using this approach. Additionally, the efficacy of such therapies is limited by pre-existing neutralizing antibodies (NAbs), especially when the virus is administered systemically for a wider biodistribution or to reach multiple metastases.