Nanoliposomes Co-Encapsulating CT Imaging Contrast Agent and Photosensitizer for Enhanced, Imaging Guided Photodynamic Therapy of Cancer

Abstract

Fluorescence (FL) and X-ray computed tomography (CT) imaging-guided photodynamic therapy (PDT) can provide a powerful theranostic tool to visualize, monitor, and treat cancer and other diseases with enhanced accuracy and efficacy. Methods: In this study, clinically approved iodinated CT imaging contrast agent (CTIA) iodixanol and commercially available photosensitizer (PS) meso-tetrakis (4-sulphonatophenyl) porphine (TPPS 4 ) were co-encapsulated in biocompatible PEGylated nanoliposomes (NL) for enhanced anticancer PDT guided by bimodal (FL and CT) imaging. Results: The NL co-encapsulation of iodixanol and TPPS 4 (LIT) lead to an increase in singlet oxygen generation by PS via the intraparticle heavy-atom (iodine) effect on PS molecules, as it was confirmed by both direct and indirect measurements of singlet oxygen production. The confocal imaging and PDT of cancer cells were performed in vitro , exhibiting the cellular uptake of TPPS 4 formulations and enhanced PDT efficacy of LIT. Meanwhile, bimodal (FL and CT) imaging was also conducted with tumor-bearing mice and the imaging results manifested high-efficient accumulation and retention of LIT in tumors. Moreover, PDT of tumor in vivo was shown to be drastically more efficient with LIT than with other formulations of TPPS 4 . Conclusion: This study demonstrated that LIT can serve as a highly efficient theranostic nanoplatform for enhanced anticancer PDT guided by bimodal (FL and CT) imaging.

Core–shell polymeric nanoparticles co-loaded with photosensitizer and organic dye for photodynamic therapy guided by fluorescence imaging in near and short-wave infrared spectral regions

“…b Fluorescence decays for HPPH in organic solvent (DMF) or in NF, post-loaded alone or with two different NIRFDs. c fluorescence of NIRFDs post-loaded to NF alone or in combination with HPPH (excitation at 808 nm) direct 1 O 2 measurement method, utilizing the luminescence emission of 1 O 2 peaked at 1270 nm to evaluate the production of 1 O 2 , which is relevant to PDT efficacy [15,36]. Figure 5a shows decays of singlet oxygen phosphorescence produced by NPs_D2 post-loaded with HPPH or HPPH/JB7-08 nanoformulations under pulsed laser excitation at 532 nm.…”

“…When molecules of ABDA and singlet oxygen interact, the anthracene moiety undergoes a specific reaction to form a 9, 10-endoperoxide product. This singlet oxygen-specific reaction can be assessed spectrophotometrically to quantify singlet oxygen production by measuring the decrease in optical absorbance at 380 nm (the absorption peak of anthracene chromophore) [27,36,37]. Figure 4b shows ABDA bleaching (change of absorption at 380 nm with time under irradiation at 532 nm) for ABDA in water and when it is added to suspensions of HPPH, HPPH/JB7-08 and HPPH/JB17-08 nanoformulations (which contain the same amount of HPPH).…”

Alliance with EPR Effect: Combined Strategies to Improve the EPR Effect in the Tumor Microenvironment

“…In this regard, assessing the EPR effect in individuals is crucial for improved therapeutic effects. Clinically available technology for imaging the EPR effect in patients, such as computed tomography, MRI could provide clinicians with valuable information for medication regimens and treatment planning, thus paving the way for personalized nanomedicine 144, 145. Individuals with tumors that exhibit high EPR would be treated with EPR-dependent nanomedicine, while combination treatment in addition to traditional nanomedicine would be applied to the individuals with tumors that produce a low EPR effect.…”

AS1411 aptamer-modified theranostic liposomes co-encapsulating manganese oxide nano-contrast agent and paclitaxel for MRI and therapy of cancer

“…[4][5][6][7] Except for the use as a drug delivery carrier, theranostic liposomes have been concerned more and more in recent years due to the demand of the simultaneous diagnosis and therapy. Such theranostic liposomes are commonly obtained by the co-encapsulation of drugs and imaging molecules, such as uorescent quantum dots, 8,9 magnetic resonance imaging contrast agents (MRI CAs), [10][11][12][13] CT imaging contrast agents, 14 photoacoustic imaging CAs, 15 and ultrasound imaging CAs. 16 Among them, MRI-based theranostic liposomes own special advantages, because MRI is a widely used non-invasive medical imaging technique in clinical diagnosis.…”