Synthesis and characterization of cisplatin-loaded, EGFR-targeted biopolymer and in vitro evaluation for targeted delivery

The design of smart targeted drug delivery systems that deliver drugs to specific cancer cells will give rise to cancer treatments with better efficacy and lower toxicity levels. We report the development and characterizations of maleimide-functionalized biopolymer (Mal-PGA-Asp) as an effective targeted drug delivery carrier synthesized from an amidation reaction between aspartylated PGA (PGA-Asp) and N-(maleimidohexanoyl)-ethylenediamine (NME). The epidermal growth factor receptor (EGFR) targeting peptide (TP13) was conjugated to Mal-PGA-Asp to obtain the targeting carrier (TP13-Mal-PGA-Asp). Cisplatin was finally loaded by complexation to form a biocompatible and tumor targeted therapeutic drug (TP13-Mal-PGA-Asp3-Pt). The resultant biopolymer with an average size 87 ± 28 nm showed a sustainable release profile with a half-maximal release time (t(1/2)) of approximately 15 h in physiological saline. Fluorescence imaging and flow cytometry analysis revealed that TP13 significantly enhanced the cellular uptake of TP13-Mal-PGA-Asp3-Pt in the human hepatoma cell line SMMC-7721. The IC(50) value demonstrated the superior anticancer activity of TP13-Mal-PGA-Asp3-Pt over PGA-Asp-Pt. Therefore, the newly developed drug carrier (TP13-Mal-PGA-Asp) obtained in this study may provide an efficient and targeted delivery of anticancer drugs, presenting a promising targeted chemotherapy in EGFR-positive cancers.