Targeting and Photodynamic Killing of Cancer Cell by Nitrogen-Doped Titanium Dioxide Coupled with Folic Acid

Abstract

Titanium dioxide (TiO2) has attracted wide attention as a potential photosensitizer (PS) in photodynamic therapy (PDT). However, bare TiO2 can only be excited by ultraviolet illumination, and it lacks specific targeting ligands, which largely impede its application. In our study, we produced nitrogen-doped TiO2 and linked it with an effective cancer cell targeting agent, folic acid (FA), to obtain N-TiO2-FA nanoconjugates. Characterization of N-TiO2-FA included Zeta potential, absorption spectra and thermogravimetric analysis. The results showed that N-TiO2-FA was successfully produced and it possessed better dispersibility in aqueous solution than unmodified TiO2. The N-TiO2-FA was incubated with human nasopharyngeal carcinoma (KB) and human pulmonary adenocarcinoma (A549) cells. The KB cells that overexpress folate receptors (FR) on cell membranes were used as FR-positive cancer cells, while A549 cells were used as FR-negative cells. Laser scanning confocal microscopy results showed that KB cells had a higher uptake efficiency of N-TiO2-FA, which was about twice that of A549 cells. Finally, N-TiO2-FA is of no cytotoxicity, and has a better photokilling effect on KB cells under visible light irradiation. In conclusion, N-TiO2-FA can be as high-value as a PS in cancer targeting PDT.

An In Vitro Study of the Photodynamic Effectiveness of GO-Ag Nanocomposites against Human Breast Cancer Cells

“…Metal-incorporated graphene has generated extensive interest in various biological applications, including biosensing, photothermal therapy, as well as photodynamic therapy [ 23 , 24 ]. Particularly, the photodynamic process quickly produces reactive oxygen species (ROS) comprising hydroxyl radicals, superoxide ions, and singlet oxygen ( 1 O 2 ), with the latter associated through the main relevant agent of cellular destruction in the photodynamic practice [ 10 , 25 ]. Numerous methodologies have been offered to increase the effectiveness of photodynamic therapy (PDT).…”

“…Numerous methodologies have been offered to increase the effectiveness of photodynamic therapy (PDT). Occasionally, PDT adequacy was observed when nanoparticles were connected as Photosensitizers ( PS ) transporters, proposing that the utilization of nanoparticles can overcome the previously mentioned restrictions [ 14 , 25 , 26 , 27 ]. Among the different nanoparticles accessible, for instance quantum dots, nanotubes, liposomal vehicles, and gold nanoparticles, the latter has pulled in generous consideration on account of their chemical latency, superb optical properties, and nominal biological toxicity [ 28 , 29 , 30 ].…”

TiO2‐Based Photocatalysis at the Interface with Biology and Biomedicine

“…Folic acid (FA) has also been used with nitrogen‐doped TiO 2 nanoconjugates as an effective targeting agent for killing KB cells under visible‐light irradiation …”

“…[66] Folic acid (FA) has also been used with nitrogen-doped TiO 2 nanoconjugates as an effectivet argeting agentf or killing KB cells under visible-light irradiation. [67] Expanding thes pectrum from UV to visible and IR wavelengths:…”

Annealing effect on the photoelectrochemical and photocatalytic performance of TiO2 nanorod arrays

“…12 Accordingly, various attempts have been carried out such as doping with impurities, [13][14][15] coupling with dyes, 16,17 and sensitizing with narrow band gap semiconductors. [18][19][20] On the other hand, fabrication of one dimensional (1-D) nanostructures, such as nanotubes, nanowires, nanobelts and nanorods, has been proved to be a promising way to enhance the solar energy conversion efficiency of TiO 2 , considering the fact that some desirable characteristics, e.g., large surface areas, longer charge carrier diffusion lengths and low reectivity, can be obtained readily.…”