br Declaration of Competing Interest br No potential conflic
Declaration of Competing Interest
No potential conflicts of interest were disclosed.
The authors thank Professor Weijie Zhao at School of Pharmaceutical Science and Technology, Dalian University of Technology, for kindly providing L-02 cell line.
We gratefully acknowledge the financial supports from the National Natural Science Foundation of China (Grant Nos. 21475015, 21775015) and Australian Research Council (DE170100092).
Appendix A. Supplementary material
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Sensors and Actuators B: Chemical
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A folic acid-sensitive polyfluorene based “turn-oﬀ” fluorescence nanoprobe T for folate receptor overexpressed cancer cell imaging
Susmita Roya, Anusha Gunukulab, Balaram Ghoshb, Chanchal Chakrabortya,
a Department of Chemistry, Birla Institute of Technology and Science (BITS) Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, 500078, India
b Department of Pharmacy, Birla Institute of Technology and Science (BITS) Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet Mandal, Hyderabad, 500078, India
Cancer cell imaging
Herein, we have developed an eﬃcient approach for folate receptor (FR) over expressed cancer cell targeting and imaging through non-covalent conjugation between folic acid (FA) and a polyfluorene based amphiphilic, fluorescent polymer nanoprobes (CPF) by fluorescence “turn oﬀ” mechanism. The pH dependent supramolecular complexation/decomplexation tendency of CPF nanoprobes with FA provides the eﬀective reversible fluores-cence “turn oﬀ/turn on” of CPF fluorescence. The complete pH dependent complexation/decomplexation phe-nomena is characterized by photophysical and morphological characterization. The FESEM image study reveals the alteration of nanosphere structure of CPF to interconnected network after complexation with FA at pH 9 and consequently restoration of nanosphere morphology by decomplexation at pH 2. Again, the CPF nanoprobes exhibit 91% fluorescence quenching even in physiological pH 7.4 to reveal that the nanoprobes can be a suitable candidate for FA targeted turn-oﬀ fluorescent nanoprobes for FA pre-treated FR-positive cancer cells in vivo study. The fluorescence of CPF nanoprobes is significantly quenched in FA pre-treated FR-positive B16F10 cancer cell whereas it remains unchanged in FR-non overexpressed normal human corneal cell (HCE cells) even after FA pre-treatment. Furthermore, the present study can provide a dissimilar protocol to use a “turn oﬀ” fluorescent nanoprobe for FR-positive cancer cell imaging using free FA and fluorescent polymer nanoparticle rather than the conventional direct FA-fluorescent conjugated polymer complex.