Multimodality imaging in nanomedicine and nanotheranostics

Accurate diagnosis of tumors needs much detailed information. However, available single imaging modality cannot provide complete or comprehensive data. Nanomedicine is the application of nanotechnology to medicine, and multimodality imaging based on nanoparticles has been receiving extensive attention. This new hybrid imaging technology could provide complementary information from different imaging modalities using only a single injection of contrast agent. In this review, we introduce recent developments in multifunctional nanoparticles and their biomedical applications to multimodal imaging and theragnosis as nanomedicine. Most of the reviewed studies are based on the intrinsic properties of nanoparticles and their application in clinical imaging technology. The imaging techniques include positron emission tomography, single-photon emission computed tomography, computerized tomography, magnetic resonance imaging, optical imaging, and ultrasound imaging.

Preparation and Control of the Formation of Single Core and Clustered Nanoparticles for Biomedical Applications Using a Versatile Amphiphilic Diblock Copolymer

We report the application of a versatile diblock copolymer,poly(ethylene oxide)-b-poly(γ-methacryloxypropyl trimethoxysilane)(PEO-b-PγMPS),to prepare nanocrystals such as iron oxide nanoparticles or quantum dots,with either a single core or multi-core cluster,for biomedical applications.This amphiphilic copolymer comprises both a hydrophilic PEO segment and a hydrophobic segment with a“surface anchoring moiety”(the silane group)which can interact effectively with the hydrophobic nanocrystals through ligand exchange.One of the unique features of this work is that we can control the formation of either single core nanoparticles or multi-core nanoclusters by simply varying the conditions of ligand exchange and aging of the mixture of block copolymer and nanoparticles without needing to change the copolymer.The morphologies of the resulting single core nanoparticles or multi-core nanoclusters were confirmed by dynamic light scattering and transmission electron microscopy.The clustered nanoparticles exhibit enhanced physicochemical properties that are beyond those expected from a simple accumulation of individual nanoparticles.Additionally,the hybrid nanoparticles containing both magnetic iron oxide nanoparticles and optical quantum dots obtained using our strategy provide have combined magnetic and optical functionalities that allow for potential new and expanded biomedical applications,as demonstrated by their use for magnetic resonance imaging and biomarker-targeted cell imaging.

Breaking the vicious cycle between tumor cell proliferation and bone resorption by chloroquine-loaded and bone-targeted polydopamine nanoparticles

The vicious cycle between tumor cell proliferation and bone resorption remarkably elevates the progression and metastasis of bone tumors.Here,we fabricated polyethylene glycol-conjugated alendronate-functionalized and chloroquine(CQ)-loaded polydopamine nanoparticles(PPA/CQ)for efficient treatment of bone tumors via breaking the vicious cycle.The nanoparticles were efficiently accumulated to the bone tissues,especially the osteolytic lesions around tumors.CQ released from PPA/CQ inhibited osteoclastogenesis via preventing the degradation of tumor necrosis factor(TNF)receptor-associated receptor 3 to attenuate the osteolysis in bone tumors.On the other hand,CQ blocked the autophagy in cancer cells,resulting in improved photothermal killing of cancer cells.Finally,the in vivo experiment revealed that PPA/CQ-associated treatment efficiently inhibited both tumor growth and osteolysis.This work suggests that autophagy inhibition-associated photothermal therapy could be a promising strategy for treating malignant bone tumors.

Multifunctional nanoparticle systems for combined chemo- and photothermal cancer therapy

Hyperthermia has long been considered as an adjuvant therapy for treating various diseases. Cancer treatment exploiting hyperthermia shows great clinical potential for a wide range of tumors. Importantly, the efficacy of hyperthermal therapy has recently been enhanced by the development of functional nanomaterials. The unique physicochemical properties of nanomaterials afford the specific localization of hyperthermia to primary tumors and early-stage cancers. In particular, due to their high rate of light-to-heat conversion and their capacity to be activated by tissue-penetrating electromagnetic radiation, near-infrared （NIR） light-absorbing plasmonic nanomaterials have attracted considerable attention as candidates for noninvasive photothermal therapy. The purpose of this article is to provide a overview on the current development in multifunctional nanomaterials capable of combined hyperthermia-chemotherapy delivery.

Encapsulation of superparamagnetic Fe_3O_4@SiO_2 core/shell nanoparticles in MnO_2 microflowers with high surface areas

Microflowers made of interconnected MnO2 nanosheets have been successfully synthesized in a microwave reactor through a hydrothermal reduction of KMnO4 with aqueous HCI at elevated temperatures in the presence of superparamagnetic Fe3O4SiO2 core-shell nanoparticles.Due to the chemical compatibility between SiO2 and MnO2,the heterogeneous reaction leads to the spontaneous encapsulation of the Fe3O4@SiO2 core-shell nanoparticles in the MnO2 microflowers.The resulting hybrid particles exhibit multiple properties including high surface area associated with the MnO2nanosheets and superparamagnetism originated from the Fe3O4@SiO2 core-shell nanoparticles.which are beneficial for applications requiring both high surface area and magnetic separation.

Nanostructured self-assemblies of photosensitive dyes: green and efficient theranostic approaches

Recently,nano theranostics,by integrating diagnostic and therapeutic functions into a nano system,have provided increasing opportunities for the design of personalized medicine in cancer.Among the construction method of various theranostic nano systems,the design of single component nanoparticles which are composed of organic photosensitive dyes has become a promising approach to constructing multifunctional nano-theranostic systems,thanks to its unique advantages such as defined structure,100%loading,and high repeatability.Specifically,depending on the inherent photonic imaging and therapeutic properties of the photosensitive dyes,the multifunctional purpose which integrates theranostic effects and targeting abilities can be realized via reasonable molecular modification and supramolecular assembly.In this review,recent advances in the development of nanostructured self-assemblies of porphyrins,phthalocyanines,and boron-dipyrromethanes for theranostics are summarized.Emphasis on their design consideration and theranostic applications are presented.Additionally,prospects for clinical practice and potential challenges of this rapidly growing field are also provided.