Discoidal Nanoparticles: reaction environment-dependent Size Response

In recent years, the develop of new drug delivery system (DDS) was necessary to optimize the treatment efficiency, thus overcoming the limits of traditional teraphy such as targeting and drug half life. However, many treatmants cause immunogenicity. Several DDS was developed such as liposomes, niosomes and other tipe of nanoparticles, but they can have some limits like the recognition and elimination of the immune system or the tumour targeting. These drawbacks can be bypassed by modifing sizes and shapes of liposomes. Discoidal Nanopartcles (DNs) are obtained from liposomes by adding Styrene-Maleic Acid copolimer (SMA) (Fig. 1). The molecular ratio between styrene and maleic anhydride, pH and temperature of microenvironment reaction can affect the synthesis of DNs [1]. In this work we studied the use of SMA as copolymer, which is able to synthesis DNs by starting from spherical liposomes (DMPC) at different molar ratio of copolymers (2:1 and 4:1), pHs (range of pH from 3.5 to 11.5) and temperatures (4°C, 25°C, 37°C, 65°C). The SMA copolymer can form DNs, and their properties depend on the reaction enviroment. In fact, at different pHs, particle sizes are modified according to these physical parameters. The modifcation of temperature can influence the synthesis of DNs. Currently, the best condition is obtained at pH = 7.4 and 25°C by using 2:1 molar ratio of copolymer. The results are in agreement with previously reported data using SMA as a copolymer under different reaction conditions [1]. These properties could be affected the synthesis of DNs as well as drug delivery, but DNs could be a innovative DDS for anticancer therapy. Acknowledgment: This research is funded by the Italian Ministry of Instruction, University, and Research under the national project PON Ricerca e Innovazione 2014-2020.