Nonionic, Water Self-Dispersible “Hairy-Rod” Poly(p-phenylene)-g-poly(ethylene glycol) Copolymer/Carbon Nanotube Conjugates for Targeted Cell Imaging

Abstract

The generation and fabrication of nanoscopic structures are of critical technological importance for future implementations in areas such as nanodevices and nanotechnology, biosensing, bioimaging, cancer targeting, and drug delivery. Applications of carbon nanotubes (CNTs) in biological fields have been impeded by the incapability of their visualization using conventional methods. Therefore, fluorescence labeling of CNTs with various probes under physiological conditions has become a significant issue for their utilization in biological processes. Herein, we demonstrate a facile and additional fluorophore-free approach for cancer cell-imaging and diagnosis by combining multiwalled CNTs with a well-known conjugated polymer, namely, poly(p-phenylene) (PP). In this approach, PP decorated with poly(ethylene glycol) (PEG) was noncovalently (π-π stacking) linked to acid-treated CNTs. The obtained water self-dispersible, stable, and biocompatible f-CNT/PP-g-PEG conjugates were then bioconjugated to estrogen-specific antibody (anti-ER) via -COOH functionalities present on the side-walls of CNTs. The resulting conjugates were used as an efficient fluorescent probe for targeted imaging of estrogen receptor overexpressed cancer cells, such as MCF-7. In vitro studies and fluorescence microscopy data show that these conjugates can specifically bind to MCF-7 cells with high efficiency. The represented results imply that CNT-based materials could easily be fabricated by the described approach and used as an efficient "fluorescent probe" for targeting and imaging, thereby providing many new possibilities for various applications in biomedical sensing and diagnosis.

Poly(p‐phenylene) with Poly(ethylene glycol) Chains and Amino Groups as a Functional Platform for Controlled Drug Release and Radiotherapy

“…The main advantages of using polymers include changing the drug solubility, permeability and retention, selectivity, radiosensitivity, and potential in photodynamic therapy . Polymers and co‐polymers such as PPP, polyethylene glycol (PEG), N ‐(2‐hydroxypropyl)‐methacrylamide copolymer (HPMA), poly‐ l ‐glutamic acid (PGA), poly(methyl methacrylate) (PMMA), and poly(2‐hydroxyethyl methacrylate) (PHEMA) are widely used as drug carrier scaffolds . Owing to various synthesis strategies, it is possible to introduce functional groups which enable further modification of the polymers with targeting and/or imaging agents .…”

Synthesis and solid-state self-assembly of poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamate)s and single-walled carbon nanotubes

“…Among a wide scope of strategies that have been explored to control the aggregation state of SWCNTs and improve SWCNT/matrix interfacial properties, block copolymers have proven effective in enhancing the solubility of SWCNTs in a wide range of conventional solvents or solid matrices through non‐covalent wrapping . In addition, self‐assembly of SWCNTs with block copolymers also lead to hybrid nano‐structures with unique material properties …”

A novel DAD type and folic acid conjugated fluorescent monomer as a targeting probe for imaging of folate receptor overexpressed cells

“…Molecular imaging with small fluorescent molecules is an extensively used method in biomedical applications along with detection of tumor cells . Various polymeric structures have been designed and applied for the targeted imaging studies by our group . Targeting of polyphenylene copolymers to breast cancer cells using Anti‐metadherin and a lectin biomolecules as fluorescent probes for in vitro imaging of cancer cells was performed and these structures allow effective visualization and discrimination of MCF7 cells from human mammary epithelial cells .…”

“…Targeting of polyphenylene copolymers to breast cancer cells using Anti‐metadherin and a lectin biomolecules as fluorescent probes for in vitro imaging of cancer cells was performed and these structures allow effective visualization and discrimination of MCF7 cells from human mammary epithelial cells . Additionally, a facile and additional fluorophore‐free approach for cancer cell‐imaging and diagnosis by combining multiwalled CNTs with a conjugated polymer, namely poly(p‐phenylene) and estrogen specific antibody was also reported . Folate receptor (FR) overexpression is a tumor marker for many human tumor cells where the receptors on the surface of tumor cells are up‐regulated in various kinds of human cancers such as breast, ovaries and kidney .…”