Functionalized Cu3BiS3 nanoparticles for dual-modal imaging and targeted photothermal/photodynamic therapy

Programmable "triple attack" cancer therapy through in situ activation of disulfiram toxification combined with phototherapeutics

Effectively and completely eliminating residual tumor cells is the key to reducing the risk of tumor metastasis and recurrence. Designing an "ideal" nanoplatform for programmable cancer therapy has great prospects for completely eliminating residual tumor cells. Herein, an intelligent nanoplatform of disulfiram (DSF)-loaded CuS-tannic acid nanohexahedrons (denoted as "DSF-CuS@TA") with thermal- and pH-sensitive degradation, as well as near-infrared (NIR-II) phototherapeutics properties, was constructed. And then, it was employed for in situ DSF toxification activation programmable "triple attack" cancer therapy. After accumulating in the tumor, DSF-CuS@TA first releases the loaded Cu(DTC)2, and simultaneously degrades and releases Cu2+ and DSF under mildly acidic stimulation to trigger instant intratumoral Cu(DTC)2 chelation, thereby achieving the "first strike." Next, under irradiation by a NIR-II laser, light energy is converted into heat to generate NIR-II photothermal therapy, thereby achieving the second strike. Subsequently, under thermal stimulation, DSF-CuS@TA degrades further, triggering the chelation of Cu(DTC)2 for a second time to reach the third strike. As expected, in vitro and in vivo studies showed that the synergistic integration of DSF-based programmed chemotherapy and NIR-II phototherapeutics could achieve effective tumor removal. Therefore, we propose a novel type of programmed therapy against cancer by designing a nanoplatform via "nontoxicity-to-toxicity" chemical chelation transformation.

Advances in nanotechnology-based targeted-contrast agents for computed tomography and magnetic resonance

X-ray computed tomography (CT) and magnetic resonance (MR) imaging are essential tools in modern medical diagnosis and treatment. However, traditional contrast agents are inadequate in the diagnosis of various health conditions. Consequently, the development of targeted nano-contrast agents has become a crucial area of focus in the development of medical image-enhancing contrast agents. To fully understand the current development of nano-contrast agents, this review provides an overview of the preparation methods and research advancements in CT nano-contrast agents, MR nano-contrast agents, and CT/MR multimodal nano-contrast agents described in previous publications. Due to the physicochemical properties of nanomaterials, such as self-assembly and surface modifiability, these specific nano-contrast agents can greatly improve the targeting of lesions through various preparation methods and clearly highlight the distinction between lesions and normal tissues in both CT and MR. As a result, they have the potential to be used in the early stages of disease to improve diagnostic capacity and level in medical imaging.

Tumor microenvironment-responsive micelles assembled from a prodrug of mitoxantrone and 1-methyl tryptophan for enhanced chemo-immunotherapy

Mitoxantrone (MX) can induce the immunogenic-cell death (ICD) of tumor cells and activate anti-tumor immune responses. However, it can also cause high expression of indole amine 2, 3-dioxygenase (IDO) during ICD, leading to T-cell apoptosis and a weakened immune response. An IDO inhibitor, 1-methyl tryptophan (1-MT), can inhibit the activity of IDO caused by MX, resulting in enhanced chemo-immunotherapy. Here, MX-1-MT was connected by ester bond which could be broken in an acidic tumor microenvironment. MX-1-MT was combined with polyethylene glycol (PEG) via a disulfide bond which could be reduced by glutathione overexpressed in tumors, thereby accelerating drug release at target sites. Folic acid-modified distearoyl phosphoethanolamine-polyethylene glycol (DSPE-PEG-FA) was introduced to form targeting micelles. The micelles were of uniform particle size, high stability, and high responsiveness. They could be taken-up by drug-resistant MCF-7/ADR cells, displayed high targeting ability, and induced enhanced cytotoxicity and ICD. Due to 1-MT addition, micelles could inhibit IDO. In vivo studies demonstrated that micelles could accumulate in the tumor tissues of nude mice, resulting in an enhanced antitumor effect and few side-effects.

Recent progress in tannic acid based approaches as a natural polyphenolic biomaterial for cancer therapy: A review

Significant advancements have been noticed in cancer therapy for decades. Despite this, there are still many critical challenges ahead, including multidrug resistance, drug instability, and side effects. To overcome obstacles of these problems, various types of materials in biomedical research have been explored. Chief among them, the applications of natural compounds have grown rapidly due to their superb biological activities. Natural compounds, especially polyphenolic compounds, play a positive and great role in cancer therapy. Tannic acid (TA), one of the most famous polyphenols, has attracted widespread attention in the field of cancer treatment with unique structural, physicochemical, pharmaceutical, anticancer, antiviral, antioxidant and other strong biological features. This review concentrated on the basic structure along with the important role of TA in tuning oncological signal pathways firstly, and then focused on the use of TA in chemotherapy and preparation of delivery systems including nanoparticles and hydrogels for cancer therapy. Besides, the application of TA/Fe3+ complex coating in photothermal therapy, chemodynamic therapy, combined therapy and theranostics is discussed.

Effect of nanoparticle size on their distribution and retention in chronic inflammation sites

Nanomedicines are increasingly researched and used for the treatment of chronic inflammatory diseases. Herein, the effect of the size of nanoparticles on their distribution and retention in chronic inflammatory sites, as compared to healthy tissues, was studied in a mouse model with chronic inflammation in one of the hind footpads. Using PEGylated gold nanoparticles of 2, 10, 100, and 200 nm, we found that although the smaller nanoparticles of 2 and 10 nm showed greater distribution and slower clearance in the inflamed footpad than the relatively larger nanoparticles of 100 and 200 nm, the larger nanoparticles of 100 and 200 nm were more selectively distributed in the inflamed hind footpad than in the healthy hind footpad in the same mouse. Based on these findings, we prepared protein nanoparticles of 100-200 nm with albumin, IgG antibody, or anti-TNF-α monoclonal antibody (mAb). The nanoparticles can release proteins in response to high redox activity and/or low pH, conditions seen in chronic inflammation sites. We then showed that upon intravenous injection, those stimuli-responsive protein nanoparticles distributed more selectively in the inflamed footpad than free proteins and remained longer in the inflamed footpad than similar protein nanoparticles that are not sensitive to high redox activity or low pH. These findings support the feasibility of increasing the selectivity of nanomedicines and protein therapeutics to chronic inflammation sites and prolonging their retention at the sites by innovative nanoparticle engineering.

Bottom-up on-surface synthesis based on click-functionalized peptide bundles

On-surface synthesis is a modern technique for the preparation of atomically low-dimensional molecular nanostructures. However, most nanomaterials grow horizontally on the surface, and the step-by-step longitudinally controllable covalent bonding reaction on the surface is rarely reported. Here, we successfully achieved bottom-up on-surface synthesis by using coiled-coil homotetrameric peptide bundles called 'bundlemers' as building blocks. Rigid nano-cylindrical bundlemer with two click-reactive functionalities at each end can be grafted vertically onto the surface or another bundlemer with complementary clickable groups by click reaction at one end, thus enabling the longitudinal bottom-up synthesis of rigid rods with an exact number of bundlemers (up to 6) on the surface. Moreover, we can graft linear poly(ethylene glycol) (PEG) to one terminal of rigid rods to obtain rod-PEG hybrid nanostructures that can be released from the surface under specific conditions. Interestingly, rod-PEG nanostructures consisting of different numbers of bundles can self-assemble in water into different nano-hyperstructures. In general, the bottom-up on-surface synthesis strategy presented here can provide a simple and accurate method to manufacture a variety of nanomaterials.

Development of "smart" drug delivery systems for chemo/PDT synergistic treatment

Although chemotherapy and photodynamic therapy (PDT) have been developed for fighting cancer, the complex and heterogeneous nature of tumors makes it difficult for a single therapy to completely inhibit tumor growth. In order to reduce multidrug resistance of cancer cells to chemotherapeutic drugs and overcome low PDT efficiency in the hypoxic tumor microenvironment (TME), chemo/PDT synergistic treatment has received much attention in recent years. Depending on the characteristic signals of TME, various drug delivery systems can be constructed to target tumors and improve the therapeutic efficacy and the pharmacokinetic profile of anticancer drugs. This review highlights the synergistic strategies, treatment protocols, and design of chemo/PDT co-therapy in recent years to explore its scope and limitations. Taking advantage of stimuli-responsive materials and active cancer-targeting agents, cancer-targeting synergistic therapy is presented and discussed, providing ideas and suggestions for the construction of chemo/PDT co-therapy "smart" nanocarriers.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Mitochondria-targeting nano therapy altering IDH2-mediated EZH2/EZH1 interaction as precise epigenetic regulation in glioblastoma

Glioblastoma (GBM) is a complex brain cancer with frequent relapses and high mortality and still awaits effective treatment. Mitochondria dysfunction is a pathogenic condition in GBM and could be a prime therapeutic target for ceasing GBM progression. Strategies to overcome brain solid tumor barriers and selectively target mitochondria within specific cell types may improve GBM treatment. Here, we present hypericin-conjugated gold nanoparticles (PEG-AuNPs@Hyp) where hypericin is a mitochondrion-targeting agent exhibiting multimodal therapy by critically impacting the IDH2 gene (Isocitrate dehydrogenase) and its interaction with polycomb methyltransferase EZH1/2 for GBM therapy. It significantly localizes in mitochondria by enhanced cellular uptake in the human GBM cell lines/three-dimensional (3D) culture model under red-light exposure. It triggers oxidative stress and changes the mitochondrial potential, with increased Bax/Bcl2 ratio enhancing GBM cell death. The suppressed expression of mutated IDH2 and polycomb group of proteins upon PEG-AuNPs@Hyp/light exposure regulates mitochondria-targeting-mediated GBM metabolism with epigenetic repression of complex machinery function. Polyubiquitination and proteasomal degradation of EZH1 indicate the implication of these polycomb proteins in GBM progression. Chromatin immunoprecipitation reveals the IDH2 and EZH1/EZH2 direct interaction, confirming the role played by IDH2 in modulating the expression of EZH1 and EZH2. In vivo studies further displayed better tumor ablation in a GBM tumor-bearing nude mouse model. The present multimodal nanoformulation compromised the functional dependency of polycomb on mitochondrial IDH2 and established the mechanism of GBM inhibition.

Polysaccharide-Based Theranostic Systems for Combined Imaging and Cancer Therapy: Recent Advances and Challenges

Designing novel systems for efficient cancer treatment and improving the quality of life for patients is a prime requirement in the healthcare sector. In this regard, theranostics have recently emerged as a unique platform, which combines the benefits of both diagnosis and therapeutics delivery. Theranostics have the desired contrast agent and the drugs combined in a single carrier, thus providing the opportunity for real-time imaging to monitor the therapy results. This helps in reducing the hazards related to treatment overdose or underdose and gives the possibility of personalized therapy. Polysaccharides, as natural biomolecules, have been widely explored to develop theranostics, as they act as a matrix for simultaneously loading both contrast agents and drugs for their utility in drug delivery and imaging. Additionally, their remarkable physicochemical attributes (biodegradability, satisfactory safety profile, abundance, and diversity in functionality and charge) can be tuned via postmodification, which offers numerous possibilities to develop theranostics with desired characteristics. Hence, we provide an overview of recent advances in polysaccharide matrix-based theranostics for drug delivery combined with magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computed tomography, and ultrasound imaging. Herein, we also summarize the toxicity assessment of polysaccharides, associated contrast agents, and nanotoxicity along with the challenges and future research directions.

Bismuth Oxychloride Nanomaterials Fighting for Human Health: From Photodegradation to Biomedical Applications

Environmental pollution and various diseases seriously affect the health of human beings. Photocatalytic nanomaterials (NMs) have been used for degrading pollution for a long time. However, the biomedical applications of photocatalytic NMs have only recently been investigated. As a typical photocatalytic NM, bismuth oxychloride (BiOCl) exhibits excellent photocatalytic performance due to its unique layered structure, electronic properties, optical properties, good photocatalytic activity, and stability. Some environmental pollutants, such as volatile organic compounds, antibiotics and their derivatives, heavy metal ions, pesticides, and microorganisms, could not only be detected but also be degraded by BiOCl-based NMs due to their excellent photocatalytic and photoelectrochemical properties. In particular, BiOCl-based NMs have been used as theranostic platforms because of their CT and photoacoustic imaging abilities, as well as photodynamic and photothermal performances. However, some reviews have only profiled the applications of dye degradation, hydrogen or oxygen production, carbon dioxide reduction, or nitrogen fixation of BiOCl NMs. There is a notable knowledge gap regarding the systematic study of the relationship between BiOCl NMs and human health, especially the biomedical applications of BiOCl-based NMs. As a result, in this review, the recent progress of BiOCl-based photocatalytic degradation and biomedical applications are summarized, and the improvement of BiOCl-based NMs in environmental and healthcare fields are also discussed. Finally, a few insights into the current status and future perspectives of BiOCl-based NMs are given.

Development of Novel Tetrapyrrole Structure Photosensitizers for Cancer Photodynamic Therapy

The effectiveness of photodynamic therapy (PDT) is based on the triad effects of photosensitizer (PS), molecular oxygen and visible light on malignant tumors. Such complex induces a multifactorial manner including reactive-oxygen-species-mediated damage and the killing of cells, vasculature damage of the tumor, and activation of the organism immunity. The effectiveness of PDT depends on the properties of photosensitizing drugs, their selectivity, enhanced photoproduction of reactive particles, absorption in the near infrared spectrum, and drug delivery strategies. Photosensitizers of the tetrapyrrole structure (porphyrins) are widely used in PDT because of their unique diagnostic and therapeutic functions. Nevertheless, the clinical use of the first-generation PS (sodium porfimer and hematoporphyrins) revealed difficulties, such as long-term skin photosensitivity, insufficient penetration into deep-seated tumors and incorrect localization to it. The second generation is based on different approaches of the synthesis and conjugation of porphyrin PS with biomolecules, which made it possible to approach the targeted PDT of tumors. Despite the fact that the development of the second-generation PS started about 30 years ago, these technologies are still in demand and are in intensive development, especially in the direction of improving the process of optimization split linkers responsive to input. Bioconjugation and encapsulation by targeting molecules are among the main strategies for developing of the PS synthesis. A targeted drug delivery system with the effect of increased permeability and retention by tumor cells is one of the ultimate goals of the synthesis of second-generation PS. This review presents porphyrin PS of various generations, discusses factors affecting cellular biodistribution and uptake, and indicates their role as diagnostic and therapeutic (theranostic) agents. New complexes based on porphyrin PS for photoimmunotherapy are presented, where specific antibodies are used that are chemically bound to PS, absorbing light from the near infrared part of the spectrum. Additionally, a two-photon photodynamic approach using third-generation photosensitizers for the treatment of tumors is discussed, which indicates the prospects for the further development of a promising method antitumor PDT.

A novel CuCoS nanozyme for synergistic photothermal and chemodynamic therapy of tumors

Multifunctional CuCoS nanoparticles with photothermal converters and dual enzymatic activities have been designed for the synergistic photothermal and chemodynamic therapy of tumors.

How do bismuth-based nanomaterials function as promising theranostic agents for the tumor diagnosis and therapy?

The complexity of tumor microenvironment and the diversity of tumors seriously affect the therapeutic effect, the focus, therefore, has gradually been shifted from monotherapy to combination therapy in clinical research in order to improve the curative effect. The synergistic enhancement interactions among multiple monotherapies majorly contribute to the birth of the multi-mode cooperative therapy, whose effect of the treatment is clearly stronger than that of any single therapy. In addition, the accurate diagnosis of the tumour location is also crucial to the treatment. Bismuth-based nanomaterials (NMs) hold great properties as promising theranostic platforms based on their many unique features that include low toxicity, excellent photothermal conversion efficiency as well as high ability of X-ray computed tomography imaging and photoacoustic imaging. In this review, we will introduce briefly the main features of tumor microenvironment first and its effect on the mechanism of nanomedicine actions and present the recent advances of bismuth-based NMs for diagnosis and photothermal therapy-based combined therapies using bismuth-based NMs are presented, which may provide a new way for overcoming drug resistance and hypoxia. At the end, further challenges and outlooks regarding this promising field are discussed accompanied with some design tips for bismuth-based NMs, hoping to provide researchers some inspirations to design safe and effective nanotherapeutic agents for the clinical treatments of cancers.

Tumor Microenvironment-Responsive Reagent DFS@HKUST-1 for Photoacoustic Imaging-Guided Multimethod Therapy

Although multimethod therapy has shown great promise for effective cancer treatment, it is still a great challenge to develop simple and effective strategies to construct multifunctional therapeutic reagents. According to the characteristics of the tumor microenvironment, such as a mild acidic environment and overexpression of H₂O₂, an intelligent therapeutic reagent with photoacoustic (PA) imaging-guided photothermal therapy, chemodynamic therapy, and in situ chemotherapy was constructed by simply loading disulfiram (DSF) in a Cu-based porous metal-organic framework (HKUST-1). The resultant material DFS@HKUST-1 shows near-infrared adsorption around 600-900 nm and effective photoacoustic imaging properties and photothermal conversion efficiency upon 808 nm irradiation. Besides, after DFS@HKUST-1 is enriched in the tumor, the acidic environment of the tumor will slowly trigger the decomposition of HKUST-1, leading to the release of Cu²⁺ ions to react with DSF and endogenous H₂O₂ to generate the Cu/DSF complex (CuET) and cytotoxic •OH for chemotherapy and chemodynamic therapy, respectively. Therefore, DFS@HKUST-1 can serve as a promising tumor microenvironment response therapeutic reagent for photoacoustic imaging-guided multimethod therapy.

Dual-path modulation of hydrogen peroxide to ameliorate hypoxia for enhancing photodynamic/starvation synergistic therapy

The common existence of hypoxia within the tumor microenvironment severely restricts the efficacy of photodynamic therapy (PDT), which is attributed to the fact that the PDT process is strongly oxygen (O2) dependent. Here, a multifunctional composite (named CPCG), which combines polyethylene glycol (PEG) functionalized cerium oxide nanoparticles (CeO2) with photosensitizer chlorin e6 (Ce6) and glucose oxidase (GOx), is reported for generating O2 within the tumor microenvironment by the dual-path hydrogen peroxide (H2O2)-modulated ways to ameliorate hypoxia, thereby enhancing the PDT efficiency. This process is realized based on the dual enzyme-like activity of CeO2. The first modulated way is to transform the superoxide anion (O2˙-) into H2O2 by the superoxide dismutase-like activity of CeO2. The second modulated way is to decompose glucose into H2O2 through the catalysis of GOx. Subsequently, H2O2 generated from the above dual modulated ways can further produce O2via the catalase-like activity of CeO2. Additionally, the depletion of glucose could impede the nutrient supply to obtain starvation therapy. Both in vitro and in vivo experiments indicate that the CPCG composite could enhance the efficacy of photodynamic/starvation synergistic therapy. Therefore, this strategy offers great potential to modulate the O2 level in the tumor microenvironment for better therapeutic outcomes, and can act as a promising candidate in photodynamic/starvation synergistic therapy.

Cell membrane camouflaged bismuth nanoparticles for targeted photothermal therapy of homotypic tumors

Bi nanoparticles (NPs) have been demonstrated as effective all-in-one type theranostic agent for imaging-guided photothermal therapy, but their applications have been limited by relatively low biocompatibility and target accumulation capacity. To address this issue, we report the camouflage of Bi NPs (size: ~42 ± 2 nm) by using the mouse colon cancer CT26 cells membrane (CT26 CCM). The camouflaging process confers the efficient coating of CCM shell layer with thickness of ~8 ± 2 nm on Bi NPs cores, which can be confirmed by TEM image, zeta potential and protein gel electrophoresis tests. Simultaneously, CCM shell has no side effects on the photoabsorption/photothermal effect. Importantly, Bi@CCM NPs retain significant features of CCM, including good biocompatibility and homologous targeting ability. When Bi@CCM dispersion was intravenously (i.v.) injected into mice, they exhibited higher blood circulation half-life (11.5 h, ~2.9 times) and accumulation amount (4.7 ± 0.56% ID/g, ~2.3 times) in homotypic CT26 tumor compared to those (4.0 h in blood and 2.03 ± 0.60% ID/g in tumor) from uncoated Bi NPs. After 808 nm laser irradiation, CT26 cancer cells could be effectively ablated after the photothermal therapy of high-accumulated Bi@CCM NPs, and then the tumor tends to be eradicated after 12 days. Thus, Bi NPs camouflaged with CT26 CCM have great potential for the targeted photothermal therapy of homotypic tumors.

Functionalized g-C3N4 nanosheets for potential use in magnetic resonance imaging-guided sonodynamic and nitric oxide combination therapy

The oxygen consumption-induced hypoxia and the high concentration of glutathione in tumor microenvironment limit the treatment outcomes of sonodynamic therapy (SDT). SDT needs to be combined with other treatment modalities to achieve the desired therapeutic efficiency. In this study, an oxidized g-C₃N₄ (OCN) nanosheet-based theranostic nanoplatform is developed for sonodynamic and nitric oxide (NO) combination therapy of cancer. The OCN nanosheets are successively modified with amino-terminated 6-armed polyethylene glycol, chlorin e6, and Gd³⁺ ions, and then the as-prepared OCN-PEG-(Ce6-Gd³⁺) nanosheets are loaded with the NO donor N,N'-di-sec-butyl-N,N'-dinitroso-1,4-phenylenediamine (BNN6). Upon ultrasound (US) irradiation, the OCN-PEG-(Ce6-Gd³⁺)/BNN6 nanocomposite can induce the generation of reactive oxygen species (ROS) and simultaneously release NO molecules to effectively kill the cancer cells, thereby significantly suppressing the tumor growth. Moreover, a good in vivo T₁-weighted magnetic resonance imaging (MRI) contrast effect is achieved after intravenous injection of OCN-PEG-(Ce6-Gd³⁺)/BNN6 due to remarkably enhanced contrast performance of the nanocomposite. Therefore, the OCN-PEG-(Ce6-Gd³⁺)/BNN6 formulation can serve as a promising theranostic agent for MRI-guided sonodynamic-NO combination therapy.

Receptor-mediated photothermal/photodynamic synergistic anticancer nanodrugs with SERS tracing function

Phototherapy, especially the photothermal therapy (PTT) and the photodynamic therapy (PDT), have become very promising in cancer treatment due to its low invasiveness and high efficacy. Both PTT and PDT involve the utilization of light energy, and their synergistic treatment should be a good solution for cancer treatment by ingenious design. The therapeutic effect of phototherapy is closely associated with the amount and location of anticancer-nanodrugs accumulated in tumor cells, and the receptor-mediated endocytosis should be an excellent candidate for enhancing anticancer-nanodrugs internalization. Surface enhanced Raman spectroscopy (SERS) imaging is suitable for tracing nanodrugs due to its high selectivity, sensitivity and reliability. In this paper, we hope to construct a receptor-mediated PTT/PDT synergistic anticancer nanodrugs and evaluate the corresponding efficacy through SERS tracing function. Here, the receptor-mediated PTT/PDT synergistic anticancer nanodrugs are prepared by the chemical modification of gold nanorods (GNRs), involving protoporphyrin IX (PpIX), 4-mecaptobenzoic acid (MBA), and folic acid (FA). The achieved results show that the receptor-mediated endocytosis can greatly facilitate the internalized amount and intracellular distribution of the nanodrugs, thus lead to the anti-cancer efficacy improvement. Importantly, this receptor-mediated PTT/PDT synergistic treatment with SERS tracing function will provide a simple and effective strategy for the design and application of anticancer phototherapy nanodrugs.

Optimal fluorescence and photosensitivity properties of dual-functional NaYb1−xF4:Tmx3+ nanoparticles for applications in imaging guided photodynamic therapy

The fluorescence and photosensitivity properties of NaYb_1−xF₄:Tm_x³⁺ nanoparticles were optimized to develop noninvasive near-infrared fluorescence imaging-guided photodynamic therapy. The emission at 800 nm from Tm³⁺ presented an exponential increase with an increase in the Tm³⁺ doping concentration from 0 to 2%. The photosensitivity properties of NaYb_1−xF₄:Tm_x³⁺ nanoparticles were also studied via the chemoprobe method, which used a reactive oxygen quencher, 1,3-diphenylisobenzofuran (DPBF). With the increase in the doping concentration of Tm³⁺, the generation rate of reactive oxygen species in NaYb_1−xF₄:Tm_x³⁺ nanoparticles decreased linearly at a rate of 0.3. The doping concentration of Tm³⁺ had two opposite effects on the 800 nm emission and generation rates of reactive oxygen species. The competitive relationship was discussed and an optimal value for the Tm³⁺ doping concentration of approximately 1% was determined. At this concentration, the energy of the Yb³⁺ excited state can be fully utilized, and the fluorescence and photosensitivity properties are an effective combination.

An optimal Tm³⁺ concentration of approximately 1% was determined for the most efficient energy distribution to balance imaging and PDT.

A full-spectrum responsive B-TiO2@SiO2–HA nanotheranostic system for NIR-II photoacoustic imaging-guided cancer phototherapy

A full-spectrum responsive B-TiO₂@SiO₂–HA nanotheranostic system has been successfully fabricated for second near-infrared photoacoustic imaging-guided synergistic cancer targeting phototherapy.

A Review on the Biodistribution, Pharmacokinetics and Toxicity of Bismuth-Based Nanomaterials

Here, bismuth-based nanomaterials (Bi-based NMs) are introduced as promising theranostic agents to enhance image contrast as well as for the therapeutic gain for numerous diseases. However, understanding the interaction of such novel developed nanoparticles (NPs) within a biological environment is a requisite for the translation of any promising agent from the lab bench to the clinic. This interaction delineates the fate of NPs after circulation in the body. In an ideal setting, a nano-based therapeutic agent should be eliminated via the renal clearance pathway, meanwhile it should have specific targeting to a diseased organ to reach an effective dose and also to overcome off-targeting. Due to their clearance pathway, biodistribution patterns and pharmacokinetics (PK), Bi-based NMs have been found to play a determinative role to pass clinical approval and they have been investigated extensively in vivo to date. In this review, we expansively discuss the possible toxicity induced by Bi-based NMs on cells or organs, as well as biodistribution profiles, PK and the clearance pathways in animal models. A low cytotoxicity of Bi-based NMs has been found in vitro and in vivo, and along with their long-term biodistribution and proper renal clearance in animal models, the translation of Bi-based NMs to the clinic as a useful novel theranostic agent is promising to improve numerous medical applications.

Investigation of cell mechanics using single-beam acoustic tweezers as a versatile tool for the diagnosis and treatment of highly invasive breast cancer cell lines: an in vitro study

Advancements in diagnostic systems for metastatic cancer over the last few decades have played a significant role in providing patients with effective treatment by evaluating the characteristics of cancer cells. Despite the progress made in cancer prognosis, we still rely on the visual analysis of tissues or cells from histopathologists, where the subjectivity of traditional manual interpretation persists. This paper presents the development of a dual diagnosis and treatment tool using an in vitro acoustic tweezers platform with a 50 MHz ultrasonic transducer for label-free trapping and bursting of human breast cancer cells. For cancer cell detection and classification, the mechanical properties of a single cancer cell were quantified by single-beam acoustic tweezers (SBAT), a noncontact assessment tool using a focused acoustic beam. Cell-mimicking phantoms and agarose hydrogel spheres (AHSs) served to standardize the biomechanical characteristics of the cells. Based on the analytical comparison of deformability levels between the cells and the AHSs, the mechanical properties of the cells could be indirectly measured by interpolating the Young's moduli of the AHSs. As a result, the calculated Young's moduli, i.e., 1.527 kPa for MDA-MB-231 (highly invasive breast cancer cells), 2.650 kPa for MCF-7 (weakly invasive breast cancer cells), and 2.772 kPa for SKBR-3 (weakly invasive breast cancer cells), indicate that highly invasive cancer cells exhibited a lower Young's moduli than weakly invasive cells, which indicates a higher deformability of highly invasive cancer cells, leading to a higher metastasis rate. Single-cell treatment may also be carried out by bursting a highly invasive cell with high-intensity, focused ultrasound.

Au2Pt-PEG-Ce6 nanoformulation with dual nanozyme activities for synergistic chemodynamic therapy / phototherapy

Although synergistic therapy for tumors has displayed significant promise for effective treatment of cancer, developing a simple and effective strategy to build a multi-functional nanoplatform is still a huge challenge. By virtue of the characteristics of tumor microenvironment, such as hypoxia, slight acidity and H₂O₂ overexpression, Au₂Pt-PEG-Ce6 nanoformulation is constructed for collaborative chemodynamic/phototherapy of tumors. Specifically, the Au₂Pt nanozymes with multiple functions are synthesized in one step at room temperature. The photosensitizer chlorin e6 (Ce6) is covalently linked to Au₂Pt nanozymes for photodynamic therapy (PDT). Interestingly, the Au₂Pt nanozymes possess catalase- and peroxidase-like activities simultaneously, which not only can generate O₂ for relaxation of tumor hypoxia and enhancement of PDT efficiency but also can produce ∙OH for chemodynamic therapy (CDT). In addition, the high photothermal conversion efficiency (η = 31.5%) of Au₂Pt-PEG-Ce6 nanoformulation provides the possibility for photoacoustic (PA) and photothermal (PT) imaging guided photothermal therapy (PTT). Moreover, the presence of high-Z elements (Au and Pt) in Au₂Pt-PEG-Ce6 nanoformulation endows it with the ability to act as an X-ray computed tomography (CT) imaging contrast agent. All in all, the Au₂Pt-PEG-Ce6 exhibits great potential in multimodal imaging-guided synergistic PTT/PDT/CDT with remarkably tumor specificity and enhanced therapy.

pH-responsive PEG-chitosan/iron oxide hybrid nanoassemblies for low-power assisted PDT/PTT combination therapy

Aim: To develop a hybrid nanoassembly platform using PEG-chitosan/iron oxide nanoparticles for effective low-power assisted photodynamic/photothermal combination therapy. Materials & methods: The hybrid nanoassemblies (NAs) were firstly fabricated by self-assembling chitosan and iron oxide nanoparticles, following which their surfaces were modified with polyethylene glycolated triphenylphosphine and loaded with methylene blue (MB) photosensitizer. The physical characteristics and phototherapy effects of these NAs were evaluated. Results: The formed MB-loaded NAs could produce both heat and singlet oxygen under low-power near-infrared irradiation, which would damage the cancer cells. Delivered by intravenous injection, the MB-loaded NAs showed high tendency to accumulate at the tumor sites, which would lead to effective cancer treatment under controlled photoexcitation without damaging the normal tissues. Conclusion: The proposed low-power assisted simultaneous photodynamic/photothermal approach effectively improves treatment efficiency and provides safe and precise treatment option.

Polydopamine Coated PB-MnO2 Nanoparticles as an Oxygen Generator Nanosystem for Imaging-Guided Single-NIR-Laser Triggered Synergistic Photodynamic/Photothermal Therapy

Exploring a combined phototherapeutic strategy to overcome the limitations of a single mode therapy and inducing high anticancer efficiency is highly promising for precision cancer nanomedicine. However, a single-wavelength laser activates dual photothermal/photodynamic therapy (PTT/PDT) treatment is still a formidable challenge. Herein, we strategically design and fabricate a multifunctional theranostic nanosystem based on chlorin e6-functionalized polydopamine (PDA) coated prussian blue/manganese dioxide nanoparticles (PB-MnO₂@PDA-Ce6 NPs). Interestingly, the obtained PB-MnO₂@PDA NPs not only offer an effective delivery system for Ce6 but also provide strong optical absorption in the near-infrared range, endowing high antitumor efficacy of PTT. More importantly, the as-prepared PB-MnO₂@PDA-Ce6 nanoagents exhibit an effective oxygen generation, superior reactive oxygen species (ROS), and outstanding photothermal conversion ability to greatly improve PTT and PDT treatments. As a result, both in vitro and in vivo treatments guided by MR imaging on liver cancer cells reveal the complete cell/tumor eradication under a single wavelength of 660 nm laser irradiation, implying the simultaneous synergistic PDT/PTT effects triggered by PB-MnO₂@PDA-Ce6 nanoplatform, which are much higher than individual treatment. Taken together, our phototherapeutic nanoagents exhibit an excellent therapeutic performance, which may act as a nanoplatform to find safe and clinically translatable routes to accelerate cancer therapeutics.

Self-assembled CeVO4/Au heterojunction nanocrystals for photothermal/photoacoustic bimodal imaging-guided phototherapy

Phototherapy, including photothermal therapy (PTT) and photodynamic therapy (PDT), has attracted great attention because it can effectively inhibit the proliferation and propagation of cancer cells. Recently, heterojunction nanomaterials have shown tremendous application value in the field of biological medicine. In this work, the CeVO4/Au heterojunction nanocrystals (NCs) are designed for photothermal/photoacoustic bimodal imaging-guided phototherapy. The as-synthesized hydrophobic oleic acid (OA)-stabilized CeVO4 nanosheets were modified with HS-PEG-OH for translating into hydrophilic ones, which can significantly improve their stability and biocompatibility. Subsequently, the plasmonic Au nanoparticles were in situ successfully deposited on the surface of HS-PEG-coated CeVO4 to form CeVO4/Au heterojunction NCs for improving the visible and near-infrared light absorption, which results in enhanced photothermal conversion performance and reactive oxygen species (ROS) generation capacity. Thus, the CeVO4/Au can cause more severe damage to cancer cells than pure CeVO4 under NIR laser irradiation. Also, CeVO4/Au can provide distinct tumor contrast by photothermal/photoacoustic bimodal bioimaging. Our results demonstrate that CeVO4/Au NCs could be used as an effective theranostic anticancer agent for near-infrared (NIR) light-mediated PTT and PDT.

A Multifunctional Cascade Bioreactor Based on Hollow-Structured Cu2 MoS4 for Synergetic Cancer Chemo-Dynamic Therapy/Starvation Therapy/Phototherapy/Immunotherapy with Remarkably Enhanced Efficacy

The unique tumor microenvironment (TME) facilitates cancer proliferation and metastasis, and it is hard to cure cancer completely via monotherapy. Herein, a multifunctional cascade bioreactor based on hollow mesoporous Cu₂ MoS₄ (CMS) loaded with glucose oxidase (GOx) is constructed for synergetic cancer therapy by chemo-dynamic therapy (CDT)/starvation therapy/phototherapy/immunotherapy. The CMS harboring multivalent elements (Cu^1+/2+ , Mo^4+/6+ ) exhibit Fenton-like, glutathione (GSH) peroxidase-like and catalase-like activity. Once internalized into the tumor, CMS could generate ·OH for CDT via Fenton-like reaction and deplete overexpressed GSH in TME to alleviate antioxidant capability of the tumors. Moreover, under hypoxia TME, the catalase-like CMS could react with endogenous H₂ O₂ to generate O₂ for activating the catalyzed oxidation of glucose by GOx for starvation therapy accompanied with the regeneration of H₂ O₂ . The regenerated H₂ O₂ can devote to Fenton-like reaction for realizing GOx-catalysis-enhanced CDT. Meanwhile, the CMS under 1064 nm laser irradiation shows remarkable tumor-killing ability by phototherapy due to its excellent photothermal conversion efficiency (η = 63.3%) and cytotoxic superoxide anion (·O₂ ^- ) generation performance. More importantly, the PEGylated CMS@GOx-based synergistic therapy combined with checkpoint blockade therapy could elicit robust immune responses for both effectively ablating primary tumors and inhibiting cancer metastasis.

Surface engineering of nanomaterials with phospholipid-polyethylene glycol-derived functional conjugates for molecular imaging and targeted therapy

In recent years, phospholipid-polyethylene glycol-derived functional conjugates have been widely employed to decorate different nanomaterials, due to their excellent biocompatibility, long blood circulation characteristics, and specific targeting capability. Numerous in vivo studies have demonstrated that nanomedicines peripherally engineered with phospholipid-polyethylene glycol-derived functional conjugates show significantly increased selective and efficient internalization by target cells/tissues. Targeting moieties including small-molecule ligands, peptides, proteins, and antibodies are generally conjugated onto PEGylated phospholipids to decorate liposomes, micelles, hybrid nanoparticles, nanocomplexes, and nanoemulsions for targeted delivery of diagnostic and therapeutic agents to diseased sites. In this review, the synthesis methods of phospholipid-polyethylene glycol-derived functional conjugates, biophysicochemical properties of nanomedicines decorated with these conjugates, factors dominating their targeting efficiency, as well as their applications for in vivo molecular imaging and targeted therapy were summarized and discussed.

Glutathione triggered degradation of polydopamine to facilitate controlled drug release for synergic combinational cancer treatment

Here we report a novel mechanism for triggering drug release in the polydopamine (PDA)-coated magnetic CuCo2S4 core-shell nanostructure by glutathione (GSH) triggered degradation of PDA for release. In the design, we used PDA coated CuCo2S4 as the nanocarrier with polyethylene glycol and folic acid targeting molecules to ensure the safe delivery of doxorubicin (DOX) to cancer cells. In addition, the controlled release could be enforced by taking advantage of the pH sensitivity of PDA to tumor acidic environments. The targeting and treatment of HeLa cancer cells were very effective and the killing was more efficient at higher levels of GSH. Furthermore, the designed system not only could be used for drug delivery but also could combine photothermal therapy with chemotherapy in a synergetic way. Plus, the system could be used for magnetic resonance imaging (MRI), which is beneficial for imaging-guided treatment.

Co-delivery of GOLPH3 siRNA and gefitinib by cationic lipid-PLGA nanoparticles improves EGFR-targeted therapy for glioma

Glioblastoma is one of the most aggressive types of brain tumor. Epidermal growth factor receptors (EGFRs) are overexpressed in glioma, and EGFR amplifications and mutations lead to rapid proliferation and invasion. EGFR-targeted therapy might be an effective treatment for glioma. Gefitinib (Ge) is an EGFR tyrosine kinase inhibitor (TKI), and Golgi phosphoprotein 3 (GOLPH3) expression is associated with worse glioma prognosis. Downregulation of GOLPH3 could promote EGFR degradation. Here, an angiopep-2 (A2)-modified cationic lipid-poly (lactic-co-glycolic acid) (PLGA) nanoparticle (A2-N) was developed that can release Ge and GOLPH3 siRNA (siGOLPH3) upon entering glioma cells and therefore acts as a combinatorial anti-tumor therapy. The in vitro and in vivo studies proved that A2-N/Ge/siGOLPH3 successfully crossed the blood-brain barrier (BBB) and targeted glioma. Released siGOLPH3 effectively silenced GOLPH3 mRNA expression and further promoted EGFR and p-EGFR degradation. Released Ge also markedly inhibited EGFR signaling. This combined EGFR-targeted action achieved remarkable anti-glioma effects and could be a safe and effective treatment for glioma. KEY MESSAGES: Angiopep-2-modified cationic lipid polymer can penetrate the BBB. Gefitinib can inhibit EGFR signaling and block the autophosphorylation of critical tyrosine residues on EGFR. GOLPH3 siRNA can be transfected into glioma and downregulate GLOPH3 expression. A2-N/Ge/siGOLPH3 can inhibit glioma growth.

A new strategy for accurate targeted diagnosis and treatment of cutaneous malignant melanoma: dual-mode phase-change lipid nanodroplets as ultrasound contrast agents

Background

Currently, effective detection and treatment of cutaneous malignant melanoma (CMM) still face severe challenges. Ultrasound molecular imaging as a noninvasive and easy-to-operate method is expected to bring improvements for tumor detection.

Purpose

The aim of this research is to prepare novel phase-change ultrasound contrast agents, Nds-IR780, which can perform not only dual-mode molecule-targeted imaging but also targeted photothermal therapy for CMM.

Methods

A double emulsion process was used to prepare the Nds-IR780. Then, the entrapment rate and drug loading of IR-780 iodide in Nds-IR780 were detected by high-performance liquid chromatography. The biocompatibility of Nds-IR780 was evaluated by a CCK-8 assay and the characteristics and stability of that were verified through the particle size analyzer, laser scanning confocal microscopy (LSCM) and transmission electron microscopy (TEM). The abilities of dual-mode molecule-targeted imaging and targeted photothermal therapy for Nds-IR780 were confirmed via the in vitro and in vivo experiments.

Results

Nds-IR780 had good size distribution, polydispersity index, stability and biosafety. The in vitro and in vivo experiments confirmed that Nds-IR780 were capable of targeting CMM cells with high affinity (22.4±3.2%) and facilitating dual-mode imaging to detect the primary lesion and sentinel lymph nodes (SLNs) of CMM. Furthermore, the photothermal ablation of CMM mediated by Nds-IR780 was very effective in vivo.

Conclusion

The newly prepared Nds-IR780 were observed to be effective targeted theranostic probe for the precise detection and targeted treatment of CMM.

Synthesis of Bi2WO6-x nanodots with oxygen vacancies as an all-in-one nanoagent for simultaneous CT/IR imaging and photothermal/photodynamic therapy of tumors

All-in-one nanoagents with a single-component and all-required functions have attracted increasing attention for the imaging-guided therapy of tumors, but the design and preparation of such nanoagents remain a challenge. Herein, we report the introduction of oxygen vacancies to traditional semiconductors with heavy-metal elements for tuning photoabsorption in the near infrared (NIR) region, by using Bi2WO6 (band-gap: ∼2.7 eV) as a model. Bi2WO6-x nanodots with sizes of ∼3 or ∼8 nm have been prepared by a facile coprecipitation-solvothermal method assisted by citric acid (CA, 0.1-1.5 g) as the reduction agent. CA confers the removal of O atoms from the [Bi2O2]2+ layer during the solvothermal process, resulting in the formation of plenty of oxygen vacancies in the Bi2WO6-x crystal. As a result, NIR photoabsorption of Bi2WO6-x nanodots can be remarkably enhanced with the increase of the CA amount from 0 to 1.0 g. Under irradiation of a single-wavelength (808 nm, 1.0 W cm-2) NIR laser, black Bi2WO6-x-CA1.0 nanodots can not only efficiently produce a sufficient amount of heat with a photothermal conversion efficiency of 45.1% for photothermal therapy, but also generate singlet oxygen (1O2) for photodynamic therapy. Furthermore, due to the presence of heavy-metal (Bi and W) elements, Bi2WO6-x-CA1.0 nanodots have high X-ray attenuation ability for CT imaging. After the Bi2WO6-x-CA1.0 nanodot dispersion is injected into the tumor-bearing mice, the tumor can be imaged by using CT and an IR thermal camera. After irradiation with a single-wavelength (808 nm, 1.0 W cm-2, 10 min) NIR laser, the tumor can be completely suppressed by the synergic photothermal and photodynamic effects of Bi2WO6-x-CA1.0 nanodots, without recurrence and treatment-induced toxicity. Therefore, Bi2WO6-x nanodots have great potential as a novel all-in-one nanoagent for the imaging and phototherapy of tumors.

A literature review on multimodality molecular imaging nanoprobes for cancer detection

Molecular imaging techniques using nanoparticles have significant potential to be widely used for the detection of various types of cancers. Nowadays, there has been an increased focus on developing novel nanoprobes as molecular imaging contrast enhancement agents in nanobiomedicine. The purpose of this review article is to summarize the use of a variety of nanoprobes and their current achievements in accurate cancer imaging and effective treatment. Nanoprobes are rapidly becoming potential tools for cancer diagnosis by using novel molecular imaging modalities such as Ultrasound (US) imaging, Computerized Tomography (CT), Single Photon Emission Tomography (SPECT) and Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), and Optical Imaging. These imaging modalities may facilitate earlier and more accurate diagnosis and staging the most of cancers.

A NIR-responsive indocyanine green-genistein nanoformulation to control the polycomb epigenetic machinery for the efficient combinatorial photo/chemotherapy of glioblastoma

Combinatorial photodynamics and chemotherapy have drawn enormous attention as therapeutic modalities via precise stimuli-responsive drug delivery for glioblastoma, which can overcome the limitations associated with conventional therapies. Herein, we have prepared an indocyanine green tagged, genistein encapsulated casein nanoformulation (ICG-Gen@CasNPs) that exhibits the near infra-red region responsive controlled release of genistein and enhanced cellular uptake in the human glioblastoma monolayer and a three-dimensional raft culture model via the enhanced retention effect. ICG-Gen@CasNPs, with the integrated photosensitizer indocyanine green within the nanoformulation, triggered oxidative stress, activating the apoptosis cascade, promoting cell cycle arrest and damaging the mitochondrial membrane potential, collectively directing glioblastoma cell death. The suppression of the polycomb group of proteins in the glioblastoma upon ICG-Gen@CasNPs/NIR exposure revealed the involvement of the epigenetic repression complex machinery in the regulation. Furthermore, ICG-Gen@CasNPs/PDT/PTT directed ubiquitination and proteasomal degradation of EZH2 and BMI1 indicates the implication of the polycomb in conferring glioblastoma survival. The increased activation of the apoptotic pathways and the generation of cellular reactive oxygen species upon inhibiting the expression of EZH2 and BMI1 strengthen our observations. It is worth noting that ICG-Gen@CasNPs robustly accumulated in the brain after crossing the blood-brain barrier, which represents the eminent biocompatibility and means that the system is devoid of any nonspecific toxicity in vivo. Moreover, a superior anti-tumor effect was demonstrated on a three-dimensional glioma spheroid model. Thus, this combinatorial chemo/photodynamic therapy revealed that ICG-Gen@CasNPs mediated epigenetic regulation, which is a crucial molecular mechanism of GBM suppression.

pH/redox dual-stimuli-responsive cross-linked polyphosphazene nanoparticles for multimodal imaging-guided chemo-photodynamic therapy

Multifunctional nanodrugs with the integration of precise diagnostic and effective therapeutic functions have shown great promise in improving the efficacy of cancer therapy. We report herein a simple and effective approach to directly assemble an anticancer drug (curcumin), a photodynamic agent (Ce6) and tumor environment-sensitive molecules into cross-linked polyphosphazene and coat on superparamagnetic Fe3O4 nanoclusters to form discrete nanoparticles (termed as FHCPCe NPs). FHCPCe NPs have high physiological stability and good biocompatibility, and can enhance accumulation in tumor tissue via the enhanced permeability and retention effect. Meanwhile, the FHCPCe NPs exhibit an effective performance of dual-modality magnetic resonance imaging (MRI) due to the Fe3O4 cores and fluorescence imaging (FL) in the xenografted HeLa tumor because of the fluorescence of Ce6. Importantly, under the conditions of supernormal glutathione levels and acidic microenvironment in tumor tissue, curcumin and Ce6 can be effectively released by the degradation of FHCPCe NPs. Therefore, excellent anti-tumor effects both in vitro and in vivo have been achieved by synergistic chemotherapy/photodynamic therapy (CT/PDT) using multifunctional NPs. Our study highlights the promise of developing multifunctional nanomaterials for accurate multimodal imaging-guided highly sensitive therapy of cancer.

Targeted Fe-doped silica nanoparticles as a novel ultrasound-magnetic resonance dual-mode imaging contrast agent for HER2-positive breast cancer

Background

Multimodal contrast agents with low toxicity and targeted modification have opened up new possibilities for specific imaging of breast cancer and shown broad application prospects in biomedicine and great potential for clinical transformation. In this work, a potential multifunctional imaging agent was developed by doping Fe into hollow silica nanoparticles (HS-Fe NPs), followed by modification with specific anti-HER2 antibodies, enabling the NPs to have dual-mode ultrasound (US)-magnetic resonance (MR)-specific imaging capacity with low toxicity.

Methods

Anti-HER2 antibodies were conjugated to silane-polyethylene glycol (PEG)-COOH-modified HS-Fe (HS-Fe-PEG) NPs to produce HER2-targeted HS-Fe-PEG (HS-Fe-PEG-HER2) NPs. The toxicity of HS-Fe-PEG-HER2 NPs on targeted cells in vitro and blood and organ tissue of mice in vivo was investigated. Distribution in vivo was also studied. Confocal laser-scanning microscopy and flow cytometry were used to evaluate the targeting ability of HS-Fe-PEG-HER2 NPs in vitro. US and MR instruments were used for imaging both in vivo and in vitro.

Results

The obtained HS-Fe-PEG-HER2 NPs (average diameter 234.42±48.76 nm) exhibited good physical properties and biosafety. In solution, they showed obvious enhancement of the US signal and negative contrast in T ₂-weighted MR imaging. The binding rate of HS-Fe-PEG-HER2 NPs to targeted cells (SKBR3) was 78.97%±4.41% in vitro. US and MR imaging in vivo confirmed that the HS-Fe-PEG-HER2 NPs were delivered passively into the tumor region of SKBR3 and bound specifically to tumor cells. Target enhancement was better than untargeted and targeted competition groups.

Conclusion

HS-Fe-PEG-HER2 NPs have potential as a low-cytotoxicity and dual-mode US-MR-specific imaging agent.

Cerasome-based gold-nanoshell encapsulating L-menthol for ultrasound contrast imaging and photothermal therapy of cancer

Various nanoformulations of perfluorocarbon have been developed thus far, to achieve ultrasound imaging of tumors and tumor-targeted therapy. However, their application has been greatly limited by their short sonographic duration and large size distribution. A novel theranostic agent was constructed based on gold nanoshell cerasome-encapsulated L-menthol (GNC-LM). Owing to the sustained and controllable generation of L-menthol bubbles under near-infrared laser irradiation, GNC-LM showed good performance in contrast enhancement of ultrasound imaging in vivo. GNC-LM could be imaged for 30 min, which is much longer than the imaging time of SonoVue (commercially used microbubbles). Moreover, photothermal therapy (PTT) based on the light-to-heat conversion of the nanosystem effectively ablated the tumor. Our study demonstrated the promising potential of the obtained GNC-LM to serve as a therapeutic nanoprobe for ultrasound contrast imaging and PTT of tumors.

Rational Design of IR820- and Ce6-Based Versatile Micelle for Single NIR Laser-Induced Imaging and Dual-Modal Phototherapy

Phototherapy as a promising cancer diagnostic and therapeutic strategy has aroused extensive attention. However, single-wavelength near-infrared (NIR) light-triggered combinational treatment of photothermal therapy (PTT) and photodynamic therapy (PDT) is still a great challenge. Herein, a multifunctional micelle activated by a single-wavelength laser for simultaneous PTT and PDT as well as fluorescence imaging is developed. Briefly, new indocyanine green (IR820) is conjugated to d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) via the linker 6-aminocaproic acid, and then, chlorin e6 (Ce6) is encapsulated into the micelles formed by TPGS-IR820 conjugates to fabricate TPGS-IR820/Ce6 micelles. As the well-designed TPGS-IR820 conjugate shares a similar peak absorption wavelength with Ce6, this micelle can be applied with a single NIR laser (660 nm). The stable micelles exhibit excellent photothermal conversion efficiency in vitro and in vivo as well as high singlet oxygen generation capacity in tumor cells. After efficient cellular internalization, the as-prepared micelles display outstanding anticancer activity upon single NIR laser irradiation in vitro and in vivo. Furthermore, TPGS-IR820/Ce6 micelles show negligible systemic toxicity. The highly safe and effective TPGS-IR820/Ce6 micelles can offer an innovative strategy to construct single NIR light-induced PTT and PDT combined phototherapy nanoplatforms via suitable modification of organic phototherapeutic agents.