Facile Optimization and Evaluation of PEG-PCL Block Copolymeric Nanoparticles for Anticancer Drug Delivery Using Copolymer Hybrids and Histoculture Drug Response Assays

The traditional method of optimizing poly(ethyleneglycol)-polycaprolactone (PEG-PCL) copolymers for drug delivery requires high reaction temperatures, long reaction times, and various organic reagents. Furthermore, the in vivo evaluations of the antitumor effects of these drug delivery systems are time consuming, with animal sacrifice, and negative environmental effects. In this paper, nanoparticles (NPs) prepared from PEG-PCL/PCL hybrids were obtained by mixing PEG-PCL and PCL copolymer in different proportions and used to deliver cisplatin, a widely used anticancer drug. Histoculture drug response assay (HDRA), a predictive method typically used to evaluate chemosensitivity, was applied to evaluate the in vivo antitumor potencies of the NPs. The PEG-PCL and PCL proportions of the PEG-PCL/PCL hybrid were found to affect the NP diameter, drug loading content, encapsulation efficiency, stability, in vitro release properties, in vitro cytotoxicity, and antitumor effect in HDRA. The optimal NPs exhibited a satisfactory antitumor effect along with comparatively low side effects during an in vivo study in a murine model. The results reveal that PEG-PCL/PCL hybrids and HDRA can be used to conveniently and easily optimize and evaluate NPs prepared from block copolymers.