Fluorescent tumor-targeted polymer-bioconjugate: A potent theranostic platform for cancer therapy

• PFBT-B with inherent fluorescence and tumor targeting properties was synthesized. • PFBT-B exhibits greenish-yellow fluorescence emission. • PFBT-B was used as cytocompatible coating on magnetite nanoparticles (MNPs) as probable hyperthermia agent. • Chemotherapeutic drug 5-Fluorouracil was loaded onto PFBT-B coated MNPs for potential use in cancer therapy. Polymer bioconjugate theranostics with inherent fluorescence and tumor targeting properties offers the advantage of diagnosis via fluorescence imaging and tumor targeted cancer therapy in a single platform without any requirement of external probes. Herein, fluorescent tumor targeted polymer biomolecule conjugate (comprising of cancer cell specific biotin moieties) was synthesized as potential theranostic platform for cancer therapy. The polymer biomolecule conjugate (PFBT-B) was used as a non-toxic, tumor-targeted, and fluorescent (greenish-yellow fluorescence) coating on magnetite nanoparticles (MNPs, a probable hyperthermia agent) and subsequently loaded with chemotherapeutic drug 5-Fluorouracil (5FU). The MNPs showed a saturation magnetization of 56.28 emu/g and coercivity of 75.5 Oe. The coating of MNPs with PFBT-B was confirmed from TEM studies which showed an average shell thickness of 1.88 nm. Drug (5FU) loading studies revealed a loading capacity of ~6.64 μg/μg of PFBT-B, while release studies showed pH-sensitive release profiles with accelerated release of drug in acidic milieu. MTT assay showed enhanced cytotoxicity of 5FU in the nanoformulated form as compared to pure 5FU. Additionally, PFBT-B coated MNPs showed preferential localization into the HeLa cancer cells as compared to HEK 293T normal cells. The inherent fluorescence and tumor targeting properties, thus, indicate that PFBT-B could serve as potential theranostic platform for cancer therapy.