In vivo study of miktoarm star copolymers as a promising nanocarrier to transfer hydrophobic chemotherapeutic agents to breast cancer tumor

In this project, in vitro and in vivo properties of drug loaded nanocarriers based on miktoarm star copolymer mPEG-Lys-PCL 2 were evaluated. Miktoarm was synthesized using ring opening polymerization reaction. Then, quercetin which is a hydrophobic plant based flavonol, was loaded into star NCs using nanoprecipitation method. The structure and biocompatibility nanocarriers were determined using proton nuclear magnetic resonance, Fourier-transform infrared spectroscopy, dynamic light scattering, hemolysis assay and lethal dose test. According to biocompatibility tests, prepared nanocarrier was practically nontoxic. The drug loading and encapsulation efficiency of nanocarriers were high because of miktoarm has two hydrophobic arms and more spaces between layers in comparison with linear copolymer with the same material. The results of MTT assay proved that quercetin-loaded star nanocarriers possess acceptable toxicity on cancerous cells which is because of the ability of miktoarm to mimic phospholipid structure. Furthermore, in vivo results showed the quercetin-loaded star nanocarriers is more effective to inhibit tumor volume than the free Quer. Also, the survival rate of mice treated with quercetin loaded star nanocarriers enhanced so that all the treated mice survived more than 75 days, and 20% of them were alive even after 85 days of experiment.