183 / 2024-06-14 23:05:48

Nanoliposomes co-encapsulating biomedical imaging regents and photosensitizers for multimodal imaging and phototherapy

Nanoliposomes,CT imaging,photoacoustic imaging,fluorescence imaging,heavy atom effect,photodynamic therapy,theranostics,photosensitizer

As nanoliposomes (NL) have been considered as an ultimate platform for theranostic nanomedicine, various biomedical imaging regents and photosensitizer (PSs) have been co-encapsulated in NL for multimodal imaging and phototherapy. PSs are ideal theranostic drugs that can be administered as both photodynamic therapy (PDT) drugs and fluorescence imaging (FI) reagents. However, PSs can only provide imaging information from the superficial tissues, which hampers its potential clinical application in bioimaging guided PDT. Although some multifunctional theranostic regents such as indocyanine green (ICG) can be treated as near-infrared (NIR) FI regents, photoacoustic (PA) imaging contrast regents, PDT drugs and photothermal therapy (PTT) regents, limited imaging depth still inhabit its further application. Some imaging contrast regents such as X-ray CT contrast regents have shown complementary combinations with FL and PA to get high spatial resolution and high-sensitivity multimodal imaging for imaging guided PDT, which enables a more precise spatiotemporal control of the localized therapeutic action. In our study, iodinated CT imaging contrast agent (CTIA) and ICG were considered to co-encapsulate with PSs in NL to explore the biomedical theranostic applications. In addition to providing CT, PA and NIR fluorescence multimodal imaging for monitoring drug biodistribution, targeting and retention, we have investigated the phototherapeutic potential of co-encapsulating CTIA and PSs in NL. The direct and indirect measurements of singlet oxygen production in CTIA and PSs co-encapsulated NL were evaluated to confirm the influence of CTIA on the PDT efficiency of PSs. The results have shown the enhanced PDT efficacy in CTIA and PSs co-encapsulated NL. It is associated with the heavy atom effect of iodine which can interaction with ICG in nanoscale. Our study demonstrated that co-encapsulating optimal biomedical imaging and phototherapy regents in nanoliposomes can serve as a highly efficient theranostic nanoplatform.