Development and characterization of conducting polymer nanoparticles for photodynamic therapy in vitro

Abstract

Conducting polymer nanoparticles (CPNPs), composed of the conducting polymer poly[2-methoxy-5-(2-ethylhexyl-oxy)-p-phenylenevinylene] (MEH-PPV) were studied for applications in biophotonics and therapeutics. The extent of cellular uptake, cytotoxicity, and effectiveness of these nanoparticles in photodynamic therapy (PDT) was investigated for four cell lines, namely TE-71, MDA-MB-231, A549 and OVCAR3. Confocal fluorescence imaging and flow cytometry show that CPNPs are taken up only in limited quantities by TE-71, while they are taken up extensively by the cancer cell lines. The uptake among the cancer cell lines was observed to vary with cell line, with CPNPs uptake increasing from MDA-MB-231 to A549 to OVCAR3. Fluorescence imaging experiments show that the CPNPs have high brightness and appear stable in the intracellular environment. No cytotoxicity of non-photoactivated CPNPs (in dark) was observed from MTT assay. After completion of PDT, the quantitative data on cell viability suggest that cell death scales across the cell lines with CPNP uptake, is light dose dependent, and is complete for OVCAR3. In addition, for OVCAR3 apoptotic cell death is observed after PDT. The reported work illustrates the potential of the intrinsically fluorescent and photoactivateable CPNPs for application in biophotonics and therapeutics.

Theranostics of Triple-Negative Breast Cancer Based on Conjugated Polymer Nanoparticles

“…Conjugated polymers with high stability and low cytotoxicity have emerged as novel photosensitizers in PDT of cancer. Among various CPs, MEH-PPV have shown promises in PDT of cancer with obvious reduction in cancer cell viability. , In addition, MEH-PPV has desired red emission (above 600 nm), which can facilitate in vivo cancer imaging, due to the merits including less tissue scattering and less blood absorption as compared to the light with lower wavelength . Therefore, we synthesized MEH-PPV nanoparticles with maleimide groups on the surface, where amphiphilic polymers, DSPE-PEG 2000 , and DSPE-PEG 2000 -MAL were used to encapsulate MEH-PPV (Figure ).…”

“…Although photosensitizers have been wrapped into silicon dioxide or adsorbed on proteins to prevent aggregation, these approaches can only solve the ACQ issue to a certain degree and usually have to sacrifice ROS generation . Recently, fluorescent conjugated polymers (CPs) with delocalized π-conjugated backbones have emerged as versatile functional materials and have been applied as imaging probes and photosensitizers with high photostability and brightness, strong fluorescence due to their high extinction coefficient and large Stokes shift, as well as low cytotoxicity under dark and acute cytotoxicity under the light irradiation. , CP nanoparticles have recently shown promising outcomes in the PDT of breast cancers. − However, to the best of our knowledge, the application of CP nanoparticles in the treatment of TNBC has not been reported yet, due to the poor diagnosis and prognosis options for TNBC. Therefore, there is still an urgent need to develop the theranostic platform with stable fluorescent imaging for detecting and monitoring TNBC as well as effective killing capability of TNBC.…”

Conjugated Polymer Nanoparticles for Bioimaging

“…Finally, Gesquiere and coworkers used MEH-PPV (see Figure 6 ) as a photosensitizer for photodynamic therapy [ 69 , 70 ]. Due to its high extinction coefficient and easy intersystem crossing to the triplet state, ROS are readily generated.…”

High photothermal conversion efficiency for semiconducting polymer/fullerene nanoparticles and its correlation with photoluminescence quenching

“…[34][35][36][37] In addition, CPs are organic and biologically inert which make them suitable candidates for biological and biomedical applications, such as in bio sensing, 38,39 bio imaging, 40,41 drug delivery and release, 42,43 and photodynamic therapy. [44][45][46][47][48][49][50] Besides, they can be easily prepared as hydrophobic nanoparticles with photo stability, biocompatibility or biodegradability. [51][52][53][54] Usually for PTT applications in medicine, the CPs are employed in the form of semiconducting polymer nanoparticles (SPNs).…”