Blocking the utilization of carbon sources via two pathways to induce tumor starvation for cancer treatment.

Glucose oxidase (GOx) is often used to starvation therapy. However, only consuming glucose cannot completely block the energy metabolism of tumor cells. Lactate can support tumor cell survival in the absence of glucose. Here, we constructed a nanoplatform (Met@HMnO2-GOx/HA) that can deplete glucose while inhibiting the compensatory use of lactate by cells to enhance the effect of tumor starvation therapy. GOx can catalyze glucose into gluconic acid and H2O2, and then HMnO2 catalyzes H2O2 into O2 to compensate for the oxygen consumed by GOx, allowing the reaction to proceed sustainably. Furthermore, metformin (Met) can inhibit the conversion of lactate to pyruvate in a redox-dependent manner and reduce the utilization of lactate by tumor cells. Met@HMnO2-GOx/HA nanoparticles maximize the efficacy of tumor starvation therapy by simultaneously inhibiting cellular utilization of two carbon sources. Therefore, this platform is expected to provide new strategies for tumor treatment.

Intestinal Absorption of Nanoparticles to Reduce Oxidative Stress and Vasoconstriction for Treating Diabetic Nephropathy.

The etiology of diabetic nephropathy (DN) is complex, and the incidence is increasing year by year. The patient's kidney showed oxidative stress damage, increasing active oxygen species (ROS) content, and vasoconstriction. Due to poor drug solubility and low renal accumulation, the current treatment regimens have not effectively alleviated glomerulopathy and other kidney damage caused by DN. Therefore, it is of great significance to explore new treatment strategies and drug delivery systems. Here, we constructed an oral nanodelivery system (Tel/CAN@CS-DA) that reduced oxidative stress and vasoconstriction. Deoxycholic acid (DA)-modified nanoparticles entered into intestinal epithelial cells (Caco2 cells) via the bile acid biomimetic pathway, then escaped from the lysosomes and eventually spat out the cells, increasing the oral absorption of nanoparticles. Chitosan (CS) nanoparticles could achieve renal targeting through specific binding with a renal giant protein receptor and deliver drugs to renal tubule epithelial cells (HK-2 cells). In vitro studies also proved that telmisartan (Tel) and canagliflozin (CAN) effectively removed cellular reactive oxygen species (ROS) and reduced HK-2 cell apoptosis caused by high glucose. In the in vivo model induced by streptozotocin (STZ), the results showed that the nanosystem not only elevated AMPK protein expression, inhibited angiotensin II (Ang II) protein expression to effectively reduce oxidative stress level, dilated renal blood vessels but also reduced the degree of inflammation and fibrosis. Overall, Tel/CAN@CS-DA multifunctional oral nanosystem can effectively treat DN with low toxicity, which provides a new idea for the treatment of DN.

Detachable Dual-Targeting Nanoparticles for Improving the Antitumor Effect by Extracellular Matrix Depletion.

In the tumor microenvironment (TME), the extracellular matrix (ECM) produced by cancer-associated fibroblasts (CAFs) forms a dense barrier that prevents nanodrugs from penetrating into deep tumor sites, leading to unsatisfactory therapeutic effects. Recently, it has been found that ECM depletion and using small-sized nanoparticles are effective strategies. Herein, we reported a detachable dual-targeting nanoparticle (HA-DOX@GNPs-Met@HFn) based on reducing ECM for enhancing penetration. When these nanoparticles reached the tumor site, the nanoparticles were divided into two parts in response to matrix metalloproteinase-2 overexpressed in TME, causing a decrease in the nanoparticle size from about 124 to 36 nm. One part was Met@HFn, which was detached from the surface of gelatin nanoparticles (GNPs), which effectively targeted tumor cells and released metformin (Met) under acidic conditions. Then, Met downregulated the expression of the transforming growth factor ß by the adenosine monophosphate-activated protein kinase pathway to inhibit the activity of CAFs, thereby suppressing the production of ECM including α-smooth muscle actin and collagen I. The other was the small-sized hyaluronic acid-modified doxorubicin prodrug with autonomous targeting ability, which was gradually released from GNPs and internalized into deeper tumor cells. Intracellular hyaluronidases triggered the release of doxorubicin (DOX), which killed tumor cells by inhibiting DNA synthesis. The combination of size transformation and ECM depletion enhanced the penetration and accumulation of DOX in solid tumors. Therefore, the tumor chemotherapy effect was greatly improved.

Multiple Strikes Achieve Remarkable Tumor-Inhibition Efficiency via Multi-mechanism Combination.

Breast cancer treatment has been challenging all the time because cancer cells have multiple signaling pathways; so, breast cancer still remains a threat to the lives and health of many patients. While common single drug therapies inhibit only one pathway, the combination of multiple mechanisms offers the potential to simultaneously suppress multiple targets and pathways to kill cancer cells more effectively. It is reported that autophagy caused by autophagy inducers and apoptosis caused by some chemotherapeutic drugs can promote ferroptosis to some extent; herein, we combined these three pathways and constructed a multifunctional dual-responsive release nanosystem of Rap@mFe3O4-DOX-HA that achieved the ferroptosis-autophagy-apoptosis synergistic effect for cancer treatment. Mesoporous Fe3O4 (mFe3O4) was set as the carrier and can also release Fe ions for ferroptosis, the autophagy inducer rapamycin (Rap) was wrapped in the carrier to trigger autophagy, and the chemotherapeutic drug doxorubicin (DOX) was used as the apoptosis inducer. At the tumor site, the prepared Rap@mFe3O4-DOX-HA nanoparticles split and released DOX/Rap in response to H+/GSH. From in vivo and in vitro studies, it was found that Rap@mFe3O4-DOX-HA nanoparticles effectively inhibited the migration of 4T1 cells, furthermore, they struck cancer cells through multiple pathways and greatly improved the anti-tumor effect. Therefore, the strategy of multi-mechanism combination achieved a therapeutic effect of 1 + 1 > 2.

Cascade nanozymes based on the "butterfly effect" for enhanced starvation therapy through the regulation of autophagy.

Although tumor starvation therapy has been proven to be an excellent method for tumor therapy, its efficiency may be weakened by autophagy, a self-protection mechanism exerted by tumors under starvation stress. Interestingly, over-activated autophagy not only improves the efficacy of starvation therapy, but also induces autophagic death. Herein, we report cascade nanozymes for enhanced starvation therapy by inducing over-activated autophagy. First, glucose oxidase (GOx) modified metal-organic frameworks (NH2-MIL88, MOF) were constructed (MOF-GOx). After loading with curcumin (Cur), Cur@MOF-GOx was further decorated with tumor-targeting hyaluronic acid (HA) to obtain Cur@MOF-GOx/HA nanozymes. GOx can catalyze glucose into H2O2 and gluconic acid, which not only leads to tumor starvation, but also provides reactants for the Fenton reaction mediated by the MOF to generate hydroxyl radicals (˙OH) for chemo-dynamic therapy. Most importantly, protective autophagy caused by tumor starvation can be over-activated by Cur to convert autophagy from pro-survival to pro-death, realizing augmented anticancer therapy efficacy. With these cascade reactions, the synergistic action of starvation, autophagy and chemo-dynamic therapy was realized. Generally, the introduction of Cur@MOF-GOx/HA into tumor cells leads to a "butterfly effect", which induces enhanced starvation therapy through subsequent autophagic cell death to completely break the self-protective mechanism of cancer cells, and generate ˙OH for chemo-dynamic therapy. Precise design allows for the use of cascade nanozymes to realize efficient cancer treatment and restrain metastasis.

Glutamine Metabolism-Regulated Nanoparticles to Enhance Chemoimmunotherapy by Increasing Antigen Presentation Efficiency.

Although the strategies to induce dendritic cells (DCs) maturation and promote their antigen presentation can stimulate the tumor immune response, the endogenous deficiency and immunosuppression of DCs reduce antigen utilization, which limits antigen presentation efficiency and reduces immunotherapy effectiveness. Here, we report an endogenous stimulus-responsive nanodelivery system (DOX@HFn-MSO@PGZL). On the one hand, doxorubicin (DOX) promoted antigen presentation by DCs after the immunogenic death of tumor cells. On the other hand, l-methionine sulfoximine (MSO) regulated the glutamine metabolism of tumor-associated macrophages (TAMs) to induce a shift toward the M1-type. M1-TAMs synergistically presented antigens with mature DCs and were more frequently produced to destroy the tumor suppressive immune microenvironment, resulting in the alleviation of DCs functional inhibition. Ultimately, the antigen presentation efficiency was improved, completely activating tumor immunity and exhibiting powerful antitumor effects.

TPGS2k-PLGA composite nanoparticles by depleting lipid rafts in colon cancer cells for overcoming drug resistance.

Recently, studies showed that the drug-resistant cell membranes have formed high-density lipid rafts regions; traditional targeted drug delivery systems can hardly break through the hard shell and deliver drugs to drug-resistant cells. Here, α-tocopherol polyethylene glycol 2000 succinate (TPGS2k) was successfully synthesized and used to modify poly (lactic-glycolic acid) nanoparticles co-loaded with doxorubicin (DOX) and simvastatin (SV) (SV/DOX@TPGS2k-PLGA NPs). The purpose of this study is to explore the synergistic effect between SV consuming cholesterol in lipid rafts and directly down-regulating P-gp expression on the intracellular drugs retention. The research highlights these nanoparticles interrupted lipid rafts (cholesterol-rich domains, where P-gp is often located), which inhibited drug efflux by down-regulating P-gp, promoted the mitochondria apoptosis and made SW620/AD300 cells (DOX-resistant colon cancer cell line) re-sensitized to DOX. Therefore, the carrier can become a promising SV-based nano-delivery system with depleting cholesterol in lipid rafts to reverse drug resistance.

Chemotherapy based on "Domino-effect" combined with immunotherapy amplifying the efficacy of an anti-metastatic treatment.

In tumor immunotherapy, Treg cells are immunosuppressive cells. In general, the main strategy of chemo immune-therapy for Treg cells is to eliminate them using chemotherapy drugs combined with immune checkpoint inhibitors. However, the dead Treg cells still exert immunosuppressive effects via the nucleoside adenosine pathway. To improve immunosuppression, we designed a nanosystem to deliver synthetic chemotherapeutics and immune activators. The homemade curcumin analog (CA) was encapsulated by α-lactalbumin (α-LA), and the Treg cell specific antibody (mAb), as a therapeutic agent, was linked to the drug-loaded protein via matrix metalloproteinase-responded peptide (P). After the cleavage peptide responded to matrix metalloproteinase (MMP-2), the CA@α-LA-P-mAb nanoparticles were separated into CA@α-LA and antibody, which can specifically enter cancer cells and Treg cells via membrane fusion and Nrp-1 receptors, respectively. Finally, we found that CA can not only lead to cell death by the chondriosome apoptosis approach but also reduce the production of Treg cells by inhibiting the expression of foxp3 (a key transcription factor of Treg cells). In addition, specific antibodies can improve the immunosuppression of existing Treg cells. The combined effect of CA and antibodies amplifies the role of chemotherapy in metastatic breast cancer.

Ovalbumin-modified nanoparticles increase the tumor accumulation by a tumor microenvironment-mediated "giant".

We designed a pH intelligently driven self-assembled nano-platform (GOx@ZIF-OVA). The nano-platform was composed of glucose oxidase (GOx), ovalbumin (OVA) and zeolitic imidazolate skeleton-8 (ZIF-8). The goal was to address the depth and cumulative limits of the drug at the tumor site. Firstly, OVA-modified GOx@ZIF could greatly increase tumor accumulation due to spontaneous self-assembly from 142.2 ± 9.1 to 705.5 ± 52.1 nm and the 5779.4 ± 598.3 nm giant at pH values of 7.4, 6.5, and 5.0, respectively. More importantly, the tumor-like sphere experiments demonstrated that the encapsulated GOx "vampires" can cut off the energy source of tumors and poisonous tumor cells without depth limitations. Furthermore, immunofluorescence assay and cytotoxicity assay tests in vivo proved that T cell infiltration could be significantly increased, triggering an effective anti-tumor immune response and inhibiting lung metastasis. Therefore, the experimental results demonstrated that the acid-smart-driven nano-platform has the potential to address the limitations of tumor depth and drug accumulation in solid tumors.

ROS-boosted photodynamic therapy against metastatic melanoma by inhibiting the activity of antioxidase and oxygen-producing nano-dopants.

The antioxidant effect weakens the ability of PDT to resist melanoma, and the hypoxic tumor environment further restricts the application of photosensitizers in tumors. Therefore, to enhance the ability of PDT to resist melanoma, we designed a sequential enhanced PDT theranostic platform (Au@MTM-HA). Firstly, the nanotherapeutic platform uses TiO2 as a photosensitizer, which is doped with MnO2 to form a mesoporous MTM. The MTM can continuously provide oxygen, thereby increasing the level of reactive oxygen species (ROS) and reducing the metastatic effect by alleviating tumor hypoxia. Furthermore, the released Au25Sv9 could inhibit the activity of antioxidant defense enzymes and reduce the scavenging of ROS and further enhance the PDT effect. Simultaneously, surface-modified HA could not only recognize CD44 receptor but also act as a sealing agent for carriers. Result: Au@MTM-HA could explosively produce a 3-fold higher ROS and improve the PDT effect. Therefore, this work may provide strong evidence for Au@MTM-HA as a new and promising PDT candidate for the treatment of metastatic melanoma.

Mild Acid-Responsive "Nanoenzyme Capsule" Remodeling of the Tumor Microenvironment to Increase Tumor Penetration.

Dense extracellular matrix (ECM) severely impedes the spread of drugs in solid tumors and induces hypoxia, reducing chemotherapy efficiency. Different proteolytic enzymes, such as collagenase (Col) or bromelain, can directly attach to the surface of nanoparticles and improve their diffusion, but the method of ligation may also impair the enzymatic activity due to conformational changes or blockage of the active site. Herein, a "nanoenzyme capsule" was constructed by combining collagenase nanocapsules (Col-nc) with heavy-chain ferritin (HFn) nanocages encapsulating the chemotherapy drug doxorubicin (DOX) to enhance tumor penetration of the nanoparticles by hydrolyzing collagen from the ECM. Col-nc could protect the activity of the enzyme before reaching the site of action while being degraded under mildly acidic conditions in tumors, and the released proteolytic enzyme could digest collagen. In addition, HFn as a carrier could effectively load DOX and had a self-targeting ability, enabling the nanoparticles to internalize into cancer cells more effectively. From in vivo and in vitro studies, we found that collagen was effectively degraded by Col-nc/HFn(DOX) to increase the accumulation and penetration of nanoparticles in the solid tumor site and could alleviate hypoxia inside the tumor to enhance the antitumor effects of DOX. Therefore, the strategy of increasing nanoparticle penetration in this system is expected to provide a potential approach for the clinical treatment of solid tumors.

Two-Way Cruise Nanosatellite Promotes Metastasis Inhibition by Immunochemotherapy.

Currently, immunochemotherapy based on tumor-associated macrophages (TAMs) is mainly used for elimination of M2 macrophages. However, these methods cannot make full use of the positive immune-modulatory effects of macrophages. This study explores a two-way cruise strategy for combining immunotherapy based on TAM phenotype reversal with classical chemotherapy, the nanosatellites (DOX@HFn-PGZL@Res) are proposed to accurately deliver the chemotherapeutic agents and immune activators to their respective target cells. When the delivery system is recruited to tumor microenvironment, the nanosatellites are separated into DOX@HFn and Res@GZL nanoparticles, which can enter cancer cells and M2-TAMs, respectively. The data show that DOX@HFn-PGZL@Res successfully re-educate M2 to M1 macrophages, resulting in an activated immune response and inhibition of tumor invasion and metastasis. In general, this work describes a two-way homing nanoplatform for the integration of immunotherapy and chemotherapy, which provides a new idea for the "attack-defense" integrated treatment of tumor.

A traceable nanoplatform for enhanced chemo-photodynamic therapy by reducing oxygen consumption.

Tumor hypoxia impedes the efficiencies of oxygen-dependent photodynamic therapy (PDT) and chemotherapy. Herein, we design a traceable nanoplatform (DOX/Met/BSA-HA-CDs) by reducing oxygen (O2) consumption to overcome the hypoxia-caused cancer therapy. Carbon dots (CDs) are used not only as a PDT agent but also applied for in vivo traceable imaging. Metformin (Met), a potent antihyperglycemic agent, to improve tumor oxygenation and enhance the efficiencies of hypoxia-caused cancer therapy. In the hypoxic tumor microenvironment, Met was released more rapidly than DOX, which is advantageous for improving hypoxic cancer to exert a better therapeutic efficiency. Ex vivo immunofluorescence staining revealed that the DOX/Met/BSA-HA-CDs nanoparticles greatly reduce O2 consumption in tumor site. Followed by in vivo synergistic treatment achieved considerably enhanced cancer therapeutic efficiency. This system holds great clinical promise as a traceable imaging approach to guide the improvement of PDT and chemotherapy efficiencies through utilizing a simple, safe method improved hypoxic tumor microenvironment.

The ratiometric fluorescence nanoparticle based on SiRB for pH detection of tumor.

Tumor pH detection and pH value change monitoring have been of great interest in the field of nanomedicine. In this study, a pH-sensitive near-infrared fluorescence probe SiRB (Si-rhodamine and Boronic acid group) was synthesized by introducing a boronic acid group into the silicon rhodamine structure. ICG (Indocyanine green) as the fluorescence internal standard and SiRB were loaded into PLGA (poly lactic-co-glycolic acid) to form PLGA-SiRB-ICG nanoparticle. The experiments showed that the size of the nanoparticle was about 90 nm, which can reach tumor passively by enhancing permeability and retention effect. PLGA in the acidic environment will accelerate the release of cleavage, and the fluorescence ratio of the two probes can reflect the specific pH value in the tumor. The results indicated that the nanoparticle could quantitatively measure the pH value of the tumor site, which is expected to be used in tumor research and treatment.

A Self-Targeting, Dual ROS/pH-Responsive Apoferritin Nanocage for Spatiotemporally Controlled Drug Delivery to Breast Cancer.

In this study, an intelligent pH and ROS dual-responsive drug delivery system based on an apoferritin (AFt) nanocage was prepared. This therapeutic system can specifically self-target 4T1 breast cancer cells by exploiting L-apoferritin receptor SCARA 5, avoiding the nonspecific binding or aggregation of nanoparticles due to the chemical functionalization for targeting. The characteristics of AFt were utilized for the simultaneous delivery of anticancer drug doxorubicin (DOX) and photosensitizer rose bengal (RB). RB exhibited efficient reactive oxygen species (ROS) generation, which can be applied to photodynamic therapy. Meanwhile, the AFt nanocage was prone to undergoing peptide backbone cleavage when oxidized by ROS. Therefore, by combining the intrinsic pH-responsive property of AFt, the dual ROS/pH-responsive system was developed. The time and location of drug release can be controlled by the combination of internal and external stimulus, which avoids the incomplete drug release under single stimulus response. The drug release rate increased significantly (from 26.1% to 92.0%) under low-pH condition (pH 5.0) and laser irradiation. More DOX from AFt entered the nucleus and killed the tumor cells, and the cell inhibition rate was up to ∼83% (DOX concentration: 5 µg/mL) after 48 h incubation. In addition, the biodistribution and the in vivo antitumor efficacy (within 14 d treatment) of the nanosystem were investigated in 4T1 breast cancer BALB/c mice. The results indicated that the system is a promising therapeutic agent involving ROS/pH dual response, self-targeting, and chemo-photodynamic therapy.

Dual-functional carbon dot-labeled heavy-chain ferritin for self-targeting bio-imaging and chemo-photodynamic therapy.

Image-guided cancer nanotheranostics with a simple nano-platform are seriously significant for nanomedicine. In this study, a novel design is described to achieve sensitive bio-imaging and effective treatment by utilizing heavy-chain ferritin (HFn) nanocages as a vector coupled with dual-functional carbon dots (CDs) on the surface of ferritin and encapsulating the chemotherapeutic drug doxorubicin (DOX). The CDs obtained herein emit bright fluorescence in the red region, which can be applied to bio-imaging in vivo. More significantly, the CDs can produce reactive oxygen species (ROS) under laser irradiation at 532 nm and cause damage to the DNA in the nucleus. These unique properties enabled CDs to act as a theranostic agent. Owing to the self-targeting ability of HFn, the final nanoparticles can internalize into cancer cells more efficiently. The nanoparticles can translocate into the nucleus after DNA damage resulting from the partial release of DOX into the cytoplasm, thereby increasing the nuclear delivery of the drug. The results of this study indicate that the multifunctional HFn(DOX)/CD nanoparticles have potential as a clinically available cancer theranostic agent to deliver diagnostic agents and therapeutic drugs into the cancer cells and thus provide a noninvasive, highly sensitive imaging approach and guidance to the chemo-photodynamic therapy simultaneously.

Oxygen Self-Production Red Blood Cell Carrier System for MRI Mediated Cancer Therapy: Ferryl-Hb, Sonodynamic, and Chemical Therapy.

Hypoxia in tumors can lead to insufficient oxygen supply during sonodynamic therapy (SDT), which in turn strengthens tumor resistance to sonodynamic efficacy. To conquer hypoxia in tumors and improve the treatment effectiveness, we developed oxygen self-production red blood cell (RBC) carrier system to decompose tumor endogenic H2O2 into O2 and combine triplex cancer therapy: ferryl-hemoglobin (ferryl-Hb), sonodynamic, and chemical therapy. Both hydrophilic sonosensitizer and doxorubicin (DOX) were encapsulated inside RBCs (DOX/Mn-TPPS@RBCs). The drug release can be improved by combining the effects of H2O2 and ultrasonic irradiation. Here, we introduced a contrast agent, meso-tetra (4-sulfonatephenyl) porphyrinate manganese(III) complex (Mn-TPPS), which could be used to enhance the signal intensity of magnetic resonance imaging (MRI) of the tumor site. The feasibility of Mn-TPPS as a sonosensitizer was investigated during SDT. Importantly, DOX/Mn-TPPS@RBCs overcame hypoxia in the tumor and improved the efficacy of SDT owing to the O2 generation by the catalase-catalyzed decomposition of tumor endogenic H2O2. Hemoglobin was simultaneously oxidized into highly oxidative ferryl-Hb species by H2O2 and reactive oxygen species, resulting in cytotoxicity. Overall, this drug delivery system is a promising therapeutic agent involving in situ production of oxygen inside the tumor, triplex therapy, and MRI.

A Hollow NaGdF4 /AFn Nanosystem Based on "Relay Race" Release for Therapy.

To develop a multifunctional nanomaterial for dual-mode imaging and synergetic chemotherapy, curcumin (CUR) was physically entrapped into hollow upconversion NaGdF4 nanomaterial, then apoferritin (AFn) loaded with doxorubicin (DOX) was attached to the NaGdF4 surface. Subsequent modification with the targeting reagent folic acid (FA) led to generation of the CUR/NaGdF4 -DOX/AFn-FA conjugate for cancer treatment. X-ray diffraction, scanning (SEM) and transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy demonstrated the successful preparation of hexagonal-phase NaGdF4 and NaGdF4 -AFn-FA. Moreover, no toxicity was observed for NaGdF4 -AFn-FA. In vitro and in vivo experiments demonstrated that the two drugs are sequentially released from the nanocomposites. This two-drug system showed strong growth inhibitory effects on MCF-7 cells. Upconversion luminescence imaging and magnetic resonance (MR) imaging of NaGdF4 -AFn-FA were carried out. The results of this study show that NaGdF4 -AFn-FA can be used for targeted anticancer drug delivery as well as imaging, a novel multi-pronged theranostic system for tumor treatment.

Construction of magnetic-carbon-quantum-dots-probe-labeled apoferritin nanocages for bioimaging and targeted therapy.

Carbon dots (CDs) are one of the most highlighted carbon-based materials for biological applications, such as optical imaging nanoprobes, which are used for labeling cells in cancer treatment mainly due to their biocompatibility and unique optical properties. In this study, gadolinium (Gd)-complex-containing CDs were obtained through a one-step microwave method to develop multimodal nanoprobes integrating the advantages of optical and magnetic imaging. The obtained Gd-CDs exhibited highly fluorescent properties with excellent water solubility and biological compatibility. Natural apoferritin (AFn) nanocages, an excellent drug delivery carrier, are hollow in structure, with their pH-dependent, unfolding-refolding process at pH 2.0 and 7.4. The chemotherapeutic drug doxorubicin (DOX) can be highly effective and encapsulated into AFn cavity. A widely used tumor-targeting molecule, folic acid (FA), functionalized the surface of AFn to obtain an active tumor targeting effect on MCF-7 cells and malignant tumors in mice models. In this study, an AFn nanocarrier encapsulating high concentration of DOX labeled with magnetic and fluorescent Gd-CDs probe was developed. Gd-CDs exhibited a unique green photoluminescence and almost no toxicity compared with free GdCl3. Furthermore, Gd-doped CDs significantly increased the circulation time and decreased the toxicity of Gd3+ in in vitro and in vivo magnetic resonance imaging, which demonstrated that the AFn nanocages labeled with Gd-CD compounds could serve as an excellent T1 contrast agent for magnetic resonance imaging. The self-assembling multifunctional Gd-CDs/AFn (DOX)/FA nanoparticles have a great potential for cancer theranostic applications.

A smart upconversion-based light-triggered polymer for synergetic chemo-photodynamic therapy and dual-modal MR/UCL imaging.

We have developed a novel nanocomposite to achieve effective therapy and live surveillance of tumor tissue. In this study, fullerene (C60) with iron oxide (Fe3O4) nanoparticles and upconversion nanophosphors (UCNPs) was loaded into N-succinyl-N'-4-(2-nitrobenzyloxy)-succinyl-chitosan micelles (SNSC) with good biocompatibility. In addition, hydrophobic anticancer drug docetaxel (DTX) was also loaded into the nanocomposites. The experiments conducted in vitro and in vivo demonstrated that C60/Fe3O4-UCNPs@DTX@SNSC can act synergistically to kill tumor cells by releasing chemotherapy drugs at specific target site as well as generating reactive oxygen using 980nm. In addition, it can also be used for non-invasive deep magnetic resonance and upconversion fluorescence dual-mode imaging. The results indicated that this system provided an efficient method to surmount the drawback of UV or visible light-responsive polymeric systems for controlled drug release and generated reactive oxygen in deep tissues and ultimately realized the integration of dual-modal imaging and treatment.