Multifunctional nanoplatforms for fluorescence imaging and photodynamic therapy developed by post-loading photosensitizer and fluorophore to polyacrylamide nanoparticles

Abstract

We report a novel post-loading approach for constructing a multifunctional biodegradable polyacrylamide (PAA) nanoplatform for tumor-imaging (fluorescence) and photodynamic therapy (PDT). This approach provides an opportunity to post-load the imaging and therapeutic agents at desired concentrations. Among the PAA nanoparticles, a formulation containing the photosensitizer, HPPH [3-(1’-hexyloxyethyl)pyropheophorbide-a], and the cyanine dye in a ratio of 2:1 minimized the undesirable quenching of the HPPH electronic excitation energy due to energy migration within the nanoparticles and/or Förster (fluorescence) resonance energy transfer (FRET) between HPPH and cyanine dye. An excellent tumor-imaging (NIR fluorescence) and phototherapeutic efficacy of the nanoconstruct formulation is demonstrated. Under similar treatment parameters the HPPH in 1% Tween 80/5% aqueous dextrose formulation was less effective than the nanoconstruct containing HPPH and cyanine dye in a ratio of 2 to 1. This is the first example showing the utility of the post-loading approach in developing a nanoconstructs for tumor-imaging and therapy.

Nanoemulsion-templated multilayer nanocapsules for cyanine-type photosensitizer delivery to human breast carcinoma cells

“…In general, two milliliters of the studied nanocarriers (with even or odd number of PE layers) were placed in a dialysis bag (Carl Roth, Germany, cut-off: 10 kDa) immersed in 30 ml phosphate buffered saline solution (PBS), pH $ 7.4 (control) or 1% HSA (Gupta et al, 2012;Opanasopit et al, 2005) dissolved in PBS. Analysis of the drug content in the released medium samples was performed using UV-Vis spectroscopy, by sampling the external solution at regular time intervals and replenishing with the same volume of fresh HSA or PBS.…”

Near-infrared fluorescent probes in cancer imaging and therapy: an emerging field

“…Gupta et al reported a new method to construct a multifunctional nanoplatform that could incorporate both the NR fluorophore and photosensitizer for NIRF imaging and photodynamic cancer therapy, making an ideal platform for simultaneous cancer imaging and therapy. 182 Karunakaran et al developed two hydrophilic porphyrins, THPP and Zn-THPP. In comparison with Photofrin, these probes have stronger intense fluorescence emission and singlet oxygen generation efficiency, showing the potential for PDT.…”

Up-Conversion Nanoparticles for Gastric Cancer Targeted Imaging and Therapy

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