Light-responsive smart drug delivery systems: synthesis and characterization of DNA-polymer and protein-polymer conjugates

Recently more effective smart drug delivery systems having potential of treating patients with less side effects compared to conventional drugs having been developed because of the increase in need for finding new methods for treating important diseases such as cancer. These systems are designed to be applied only to desired parts without spreading in the whole body by targeting polymeric nanoparticles appropriately to dieased area after loading drugs in them. Using amphiphilic conjugates self-assembling in suitable solvents in order to synthesize delivery systems for aforementioned purposes enables to obtain such systems easily. Hydrophobic and hydrophilic blocks are joined together for building amphiphilic structures by using different conjugation systems. Amphiphilic structures may be prepared by using only synthetic polymers. On the other hand biomacromolecules are nowadays widely used as hydrophilic blocks for the reason of being biocompatible. In this study, a hydrophobic copolymer was synthesized via ATRP of a methacrylate monomer containing photoactive coumarin group and a tert-butyl acrylate monomer. Two different biomacromolecules were used as hydrophilic blocks in amphiphilic structures. First, 5ʹ-aminohexyl functionalized oligonucleotide was conjugated to PCMAtBA polymer via CuAAC click reaction. Obtained OLN-polymer and conjugate was characterized with FT-IR, DLS, UV and fluorescence spectroscopy. BSA protein was used as another hydrophilic block. After conjugation of BSA to hydrophobic polymer via click reaction, characterization of the conjugate was carried out using FT-IR, DSC, SDS-PAGE, UV and fluorescence spectroscopy. Micelles of the synthesized conjugates were formed in distilled water and particule sizes of the micelles were observed via DLS. DLS measurements were repeated after UV irradiation of BSA-PCMAtBA micelles at 350 nm for 1 hour. Difference in sizes of irradiated and non-irradiated micelles were compared.