A mitochondria-targeting dihydroartemisinin derivative as a reactive oxygen species -based immunogenic cell death inducer.

Immunogenic cell death (ICD) can activate the anticancer immune response and its occurrence requires high reliance on oxidative stress. Inducing mitochondrial reactive oxygen species (ROS) is a desirable capability for ICD inducers. However, in the category of ICD-associated drugs, numerous reported ICD inducers are a series of anthracyclines and weak in ICD induction. Herein, a mitochondria-targeting dihydroartemisinin derivative (T-D) was synthesized by conjugating triphenylphosphonium (TPP) to dihydroartemisinin (DHA). T-D can selectively accumulate in mitochondria to trigger ROS generation, leading to the loss of mitochondrial membrane potential (ΔΨm) and ER stress. Notably, T-D exhibits far more potent ICD-inducing properties than its parent compound. In vivo, T-D-treated breast cancer cell vaccine inhibits metastasis to the lungs and tumor growth. These results indicate that T-D is an excellent ROS-based ICD inducer with the specific function of trigging vigorous ROS in mitochondria and sets an example for incorporating artemisinin-based drugs into the ICD field.

GPX4 inhibition synergistically boosts mitochondria targeting nanoartemisinin-induced apoptosis/ferroptosis combination cancer therapy.

Artemisinin, originally used for its antimalarial activity, has received much attention in recent years for cancer therapy. The anticancer mechanisms of artemisinin are complicated and debatable. Challenges in the delivery of artemisinin also persist because the anticancer effect of artemisinin alone is often not satisfactory when used with traditional nanocarriers. We herein report the mitochondrial delivery of artemisinin with extremely high anticancer capacity. The action mode of artemisinin in the mitochondria of cancer cells includes heme-participating and oxygen-independent conversion of artemisinin into a carbon-centered radical, which is partly converted into ROS in the presence of molecular oxygen. We reveal that artemisinin alone in the mitochondria can induce strong cancer cell apoptosis. In addition, due to the weak inhibition of GPX4 activity by artemisinin, weak ferroptosis is also observed. We further discover that GPX4 activity in MCF-7 cells is greatly inhibited by RSL3 to synergistically enhance the anticancer capacity of artemisinin via enhancing ferroptosis. The synergistic anticancer activity of artemisinin and RSL3 in the mitochondria not only improves cancer cell-killing ability, but also inhibits the re-proliferation of residual cancer cells. This study provides a new insight into developing highly efficient and practical artemisinin nanomedicines for cancer therapy.

Dual-step irradiation strategy to sequentially destroy singlet oxygen-responsive polymeric micelles and boost photodynamic cancer therapy.

Nanotechnology provides a powerful tool to overcome many disadvantages of small-molecule photosensitizers for photodynamic cancer therapy, such as hydrophobicity, rapid blood clearance, low accumulation in tumor tissue and low cell penetration, etc. The occurrence of quench in photosensitizer-loaded nanoparticle greatly downregulates the ability to generate singlet oxygen with light irradiation. Stimuli-responsive nanocarriers can improve the efficacy of PDT to a certain extent. However, insufficient release of photosensitizer from either endogenous or exogenous stimuli responsive nanocarriers in the short period of light irradiation restricts full usage of the photosensitizer delivered into cancer cells. We here report a dual-step light irradiation strategy to enhance the efficacy of cancer PDT. Ce6 as a photosensitizer is loaded in singlet oxygen-sensitive micelles (Ce6-M) via self-assembly of amphiphilic polymer mPEG2000-TK-C16. After co-incubation of Ce6-M with cancer cells or i.v. injection of Ce6-M, cancer cells or tumor tissues are irradiated with light for a short time to trigger Ce6 release, and 2 h later, re-irradiated for relatively long time. The sufficient release of Ce6 in the period between twice light irradiation significantly improves the generation of singlet oxygen, leading to more efficient cancer therapeutic effects of dual-step irradiation than that of single-step irradiation for the same total irradiation time.

Does Economic Overheating Provide Positive Feedback on Population Health? Evidence From BRICS and ASEAN Countries.

This paper explores the relationship of real GDP per capita with cancer incidence applying panel threshold regression model in BRICS and ASEAN countries. The empirical results highlight that the business cycle has an inverted-U correlation with population health indicators and a non-linear single threshold effect. In BRICS countries, the health-promoting effect of economic growth is significantly weaker when exceeding the threshold. Similarly, economic growth in ASEAN countries, even worsens population health, after the turning point. These asymmetric effects are strongly related to the response of regional economic globalization health policies. Changes in economic expansion and overheating may have serious adverse effects on health care systems in emerging economies. Governments should adopt more aggressive health care policies during economic overheating, to avoid wasting health care resources.

Reduction-active Fe3O4-loaded micelles with aggregation- enhanced MRI contrast for differential diagnosis of Neroglioma.

Differential diagnosis between inflammatory mass and malignant glioma is of great significance to patients, which is the basis for developing accurate individualized treatment. Due to the lack of non-invasive imaging characterization methods in the clinical application, the current diagnosis grading of glioma mainly depended on the pathological biopsy, which is complicated and risky. This study aims to develop a non-invasive imaging differential diagnosis method of glioma based on the reduction activated strategy of intracellular aggregation of sensitive superparamagnetic Fe3O4 nanoparticles (SIONPs). In vitro and in vivo magnetic resonance imaging results indicated that SIONPs could specifically increase the T2 relaxation rate and enhance MR imaging in tumor with redox microenvironment by the response-aggregation in the tumorous site. In vivo experiments also demonstrate that the substantial improvement of T2-weighted imaging contrast could be used to differentiate inflammatory mass and malignant glioma. The reduction-active MR imaging contrast agent offers a new paradigm for designing "smart" MR imaging probes of differential diagnosis of the tumor.

An Oxidation-Enhanced Magnetic Resonance Imaging Probe for Visual and Specific Detection of Singlet Oxygen Generated in Photodynamic Cancer Therapy In Vivo.

Singlet oxygen is regarded as the primary cytotoxic agent in cancer photodynamic therapy (PDT). Despite the advances in optical methods to image singlet oxygen, it remains a challenge for in vivo application due to the limited tissue penetration depth of light. Up to date, no singlet oxygen-specific magnetic resonance imaging (MRI) probe has been reported. Herein, a T2 -weighted MRI probe is reported to visually detect singlet oxygen generated in PDT in vitro and in vivo. The MRI probe Ce6/Fe3 O4 -M is constructed by co-encapsulation of photosensitizer Ce6 and Fe3 O4 nanoparticles in mPEG2000 -TK-C16 micelles. Thioketal (TK) linker in the probe is highly sensitive to singlet oxygen, but lowly sensitive to other reactive oxygen species (ROS) existing in physiological and pathological environments. Singlet oxygen, generated with light irradiation, triggers the cleavage of TK, which leads to loss of surface polyethylene glycol, increment of the hydrophobicity, and aggregation of Fe3 O4 nanoparticles. Subsequently, negatively enhanced T2 -weighted MRI signal is obtained for visual detection of singlet oxygen in the solution, cancer cells, and in vivo. This oxidation responsive MRI probe is expected to hold great promise in evaluating the ability of photosensitizers to generate singlet oxygen and in predicting the therapeutic efficacies of PDT in vivo.

Physiological and Transcriptional Response of Xanthomonas oryzae pv. oryzae to Berberine, an Emerging Chemical Control.

Berberine, a botanical drug, has great ability to inhibit the growth of Xanthomonas oryzae pv. oryzae. However, the antibacterial mechanism of berberine against X. oryzae pv. oryzae remains poorly understood. In this study, we investigated the physiological and transcriptional response of X. oryzae pv. oryzae to berberine. When strain X. oryzae pv. oryzae GX13 was treated with berberine (10 µg/ml), the hypersensitive response in tobacco, virulence to rice, pathogen population in the rice xylem, production of extracellular polysaccharide (EPS), and activity of extracellular hydrolases decreased, but the levels of pyruvate and ATP increased. Moreover, biofilm formation was inhibited, and the cell membrane was damaged. Transcriptome sequencing analysis showed downregulated expression of gspD, gspE, and gspF, involved in the type II secretion system (T2SS); hrcC, hrcJ, hrcN, and others, involved in the type III secretion system (T3SS); gumB and gumC, associated with EPS; zapE, ftsQ, and zapA, associated with cell division; lpxH, lpxK, kdtA, and others, associated with the membrane; and pyk, pgk, and mdh, encoding pyruvate kinase, phosphoglycerate kinase, and malate dehydrogenase, respectively. Upregulated expression was observed for nuoA, nuoB, and nuoH, encoding the NADH dehydrogenase complex, and atpF, atpC, and atpB, encoding ATP synthase. An adenylate cyclase (CyaA) fusion assay showed that berberine affects type three effector protein secretion via the T3SS and reduces effector translocation in X. oryzae pv. oryzae. It is speculated that the negative growth and virulence phenotypes of berberine-treated X. oryzae pv. oryzae GX13 may involve differentially expressed genes associated with cytoarchitecture and energy metabolism, and these effects on primary cell function may further dampen virulence and result in differential expression of T3SS- and T2SS-related genes.

A simple and rapid method for the determination of lead dioxide in minium by headspace gas chromatographic technique.

This paper demonstrated a simple and rapid approach for the determination of lead dioxide in minium using a headspace gas chromatographic (GC) technique. This new approach was based on the measurement of carbon dioxide from the redox reaction between lead dioxide and oxalic acid in a sealed headspace vial. The obtained results indicated that the new approach had good measurement accuracy (relative errors ≤8.71%) and precision (RSD ≤2.86%). Moreover, the limit of quantification (LOQ) and limit of detection (LOD) for this new approach were respectively 0.34% and 0.10%, and the recoveries ranged from 97.9 to 101.7%. The new approach is low-cost and reliable, which has potential for use in the analysis of lead dioxide in minium and related products.

Effect of Poly(ethylene glycol) (PEG) Surface Density on the Fate and Antitumor Efficacy of Redox-Sensitive Hybrid Nanoparticles.

The effects of poly(ethylene glycol) (PEG) on improving the biological compatibility and circulation time of nanocarriers are determined by the surface density of PEG on nanoparticles. PEG with high surface density on nanocarriers has greater accumulation in tumor tissues. However, this impairs the release of drugs loaded in the nanoparticles in the tumor tissues. The relations and internal regularities between the controlled stripping of PEG of nanoparticles and its fate and antitumor efficacy in vivo remain unsolved. Redox-sensitive hybrid nanoparticles coated with varied PEG densities were prepared by blending a redox-sensitive polymer of DLPE-SS-MPEG. To keep identical nanoproperties, these nanoparticles were prepared with a similar size distribution of around 100 nm. The effects of controlled stripping of PEG on antitumor activities of nanoparticles were then investigated. As the PEG surface density increased, lower cellular internalization by tumor cells was observed. However, nanoparticles with higher controlled stripping of PEG showed greater accumulation in tumor tissues and advanced antitumor activities in vivo.

Biotinylated and fluorophore-incorporated polymeric mixed micelles for tumor cell-specific turn-on fluorescence imaging of Al3.

Excessive amounts of Al3+ in the human body can cause adverse effects on immune function and induce several neurodegenerative disorders. So far, most of the reported fluorescent probes for Al3+ present some common drawbacks, such as low sensitivity and poor water solubility. In addition, a number of traditional fluorescent probes failed to image Al3+ in tumor cells due to the lack of tumor cell targeting capacity and cell penetrating abilities. To overcome these shortcomings, we constructed tumor-targeting fluorescent mixed nano-micelles (mPEG-Dye-Biotin) with an average particle size of 21 nm from an amphiphilic polymer containing a Schiff-base fluorescent unit (mPEG-Dye) and another amphiphilic polymer containing a tumor cell recognition ligand (DSPE-PEG-Biotin), through the co-self-assembly of both amphiphilic polymers in water using the film rehydration method. The as-prepared nanoprobe showed a highly sensitive and selective turn-on fluorescence response to Al3+ in aqueous solution with a low detection limit. MTT assay revealed the negligible cytotoxicity of the mPEG-Dye-Biotin nanoprobe to both HeLa cells and COS-7 cells, indicating the safety of mPEG-Dye-Biotin for biological applications. More importantly, the biotinylated nanoprobe showed better ability to enter biotin receptor-positive HeLa cells than that of the non-biotinylated micelle mPEG-Dye, which made it more suitable for imaging Al3+ in biotin receptor-positive tumor cells. This work provides a simple and general strategy to design a highly sensitive and tumor cell-specific metal ion nanoprobe, which can not only be applied in Al3+ imaging, but can also be extended to other ions or biomolecules by changing the incorporated fluorescent unit in the amphiphilic polymer.

Tumor acidity activated triphenylphosphonium-based mitochondrial targeting nanocarriers for overcoming drug resistance of cancer therapy.

The drug resistance in cancer treatment with DOX is mainly related to the overexpression of drug efflux proteins, residing in the plasma and nuclear membranes. Delivering DOX into the mitochondria, lacking drug efflux proteins, is an interesting method to overcome DOX resistance. To solve the problem of positively charged triphenylphosphonium (TPP) for mitochondrial targeting in vivo, a charge reversal strategy was developed. Methods: An acidity triggered cleavable polyanion PEI-DMMA (PD) was coated on the surface of positively charged lipid-polymer hybrid nanoparticle (DOX-PLGA/CPT) to form DOX-PLGA/CPT/PD via electrostatic interaction. The mitochondrial localization and anticancer efficacy of DOX-PLGA/CPT/PD was evaluated both in vitro and in vivo. Results: The surface negative charge of DOX-PLGA/CPT/PD prevents from rapid clearance in the blood and improved the accumulation in tumor tissue through the enhanced permeability and retention (EPR) effect. The hydrolysis of amide bonds in PD in weakly acidic tumor tissue leads to the conversion of DOX-PLGA/CPT/PD to DOX-PLGA/CPT. The positive charge of DOX-PLGA/CPT enhances the interaction with tumor cells, promotes the uptake and improves DOX contents in tumor cells. Once endocytosed by tumor cells, the exposed TPP in nanomedicine results in effective mitochondrial localization of DOX-PLGA/CPT. Afterward, DOX can release from the nanomedicine in the mitochondria, target mtDNA, induce tumor cells apoptosis and overcome DOX resistance of MCF-7/ADR breast cancer. Conclusion: Tumor acidity triggered charge reversal of TPP-containing nanomedicine and activation of mitochondrial targeting is a simple and effective strategy for the delivery of DOX into the mitochondria of cancer cells and overcoming DOX resistance of MCF-7/ADR tumor both in vitro and in vivo, providing new insight in the design of nanomedicines for cancer chemotherapy.

Aggregation-Induced Emission (AIE) Polymeric Micelles for Imaging-Guided Photodynamic Cancer Therapy.

Photodynamic therapy (PDT) is a noninvasive treatment for selectively killing malignant tumor cells. The photosensitizer is a necessary component of photodynamic nanomedicine. Many efforts have been made to develop new photosensitizers for efficient cancer photodynamic therapy. In this work, we report a novel nano photosensitizer, polymeric micelles (AIE-M) with aggregation induced emission characteristic, for photodynamic cancer therapy. AIE-M with sub-20 nm particle size is prepared by the self-assembly of salicylaldazine-incorporated amphiphilic polymer (AIE-1), which can produce reactive oxygen species (ROS) with light irradiation in solution. After uptake by cancer cells, AIE-M can specially sojourn in plasma membranes of cancer cells at the early stage and predominantly accumulate in the mitochondria of cancer cell at the late stage. The phototoxicity of AIE-M, resulting from the generation of intracellular ROS with light irradiation, can efficiently cause cancer cells death by apoptosis and necrosis. The advantages of AIE-M as a nano photosensitizer include the small size, highly colloidal stability in the process of preparation and storage, and high cell penetration. The ultra-low Critical Micelle Concentration (CMC) of AIE-1, negligible dark toxicity and super phototoxicity of AIE-M suggest its promising potential for image-guided PDT.

Fluorinated polymeric micelles to overcome hypoxia and enhance photodynamic cancer therapy.

Photodynamic therapy (PDT) as an alternative choice of cancer treatment method has attracted increasing attention in the past few decades. A sufficient amount of oxygen is essential for the production of singlet oxygen (1O2) in successful PDT; however, hypoxia is a typical hallmark of cancer, which is one of the most important limitation factors of PDT. To overcome the hypoxic tumour microenvironment and achieve highly efficient photodynamic cancer therapy, herein, a photosensitizer Ce6-loaded fluorinated polymeric micelle (Ce6-PFOC-PEI-M) was constructed via the self-assembly of an amphiphilic polymer prepared from perfluorooctanoic acid and branched polyethyleneimine (10 kDa). The introduction of perfluoroalkyl groups in the polymeric micelle Ce6-PFOC-PEI-M retained the oxygen-carrying capacity similar to perfluorocarbon, increased the oxygen level and overcame the hypoxia in C6 glioma cells under oxygen-deficient conditions. As a control, Ce6-OC-PEI-M without a perfluoroalkyl group could not increase the oxygen level in C6 glioma cells under the same conditions. With laser irradiation, Ce6-PFOC-PEI-M generated much more reactive oxygen species (ROS) in C6 glioma cells than Ce6-OC-PEI-M, leading to a higher phototoxicity in vitro and photodynamic tumour growth inhibition in vivo than Ce6-OC-PEI-M. Furthermore, there were no differences in the contents of Ce6 in tumour tissue between Ce6-PFOC-PEI-M and Ce6-OC-PEI-M. The higher efficacy of Ce6-PFOC-PEI-M in PDT is ascribed to its oxygen-carrying ability rather than higher content of Ce6 in the tumour. The presented fluorinated polymeric micelle could provide a new platform in the delivery of various photosensitizers and has great potential to improve the efficacy of PDT cancer therapy.

Gadolinium-chelate functionalized bismuth nanotheranostic agent for in vivo MRI/CT/PAI imaging-guided photothermal cancer therapy.

Multifunctional nanomaterials with simple structure and good biosafety, integrating multimodal imaging and therapeutic functions, can facilitate the development of clinical cancer treatments. Here, a simple but powerful pure bismuth based nanoparticle (Gd-PEG-Bi NPs) was developed from pure Bi NPs and gadolinium-diethylenetriaminepentaacetic acid-bis-tetradecylamide, which not only shows high quality MRI/CT/PAI triple-modal imaging, but can also be a potent photothermal therapy agent under the guidance of the triple-modal imaging. The Gd-PEG-Bi NPs showed good stability and excellent biocompatibility. In vitro and in vivo study demonstrated that Gd-PEG-Bi NPs have ultrahigh X-ray attenuation coefficient, short T1 relaxation time in MRI, and strong PAI signal. Following the imaging diagnosis, the excellent light-to-heat conversion efficiency of Gd-PEG-Bi NPs was capable of suppressing the tumor growth effectively under near-infrared laser radiation in vivo. Such multifunctional nanoparticles were ideal candidates for cancer diagnosis and treatment.

Tetramethylpyrazine phosphate and borneol combination therapy synergistically attenuated ischemia-reperfusion injury of the hypothalamus and striatum via regulation of apoptosis and autophagy in a rat model.

The combination of tetramethylpyrazine (TMP) and borneol (BO) has shown promise for treatment of cerebral ischemia in clinical and experimental studies. However, the mechanism for the synergistic effect of these compounds is unclear. In this study, global cerebral ischemia-reperfusion (GCIR) was induced in rats that were subsequently treated with tetramethylpyrazine phosphate (TMPP) (13.3 mg/kg), BO (0.16 g/kg), or the combination TMPP + BO. Neuronal ultrastructure and intracellular calcium [Ca2+]i levels were evaluated in hypothalamus and striatum. Neuron autophagy was evaluated by expression of LC3 II/I, ULK1, Beclin1, BNIP3, mTOR, and pAMPK. Neuron apoptosis was examined via apoptosis index (AI) and expression of p53, Bcl-2, Bax, and caspase-3. Both monotherapies significantly improved neuronal ultrastructure, reduced numbers of apoptotic neurons and AI, attenuated [Ca2+]i overload, increased expression of pAMPK, ULK1, and LC3 II/I, and markedly reduced expression of mTOR, p53, and caspase-3 in hypothalamus and striatum. In hypothalamus, TMPP increased Bcl-2 expression and decreased Bax expression. In striatum, TMPP and BO increased Beclin1 expression while TMPP increased Bcl-2 expression and decreased Bax expression. TMPP + BO combination therapy enhanced expression of LC3 II/I, pAMPK, mTOR, and ULK1 in hypothalamus, and pAMPK, mTOR, ULK1, Beclin1, and Bax in striatum compared to the monotherapies. Combination therapy synergistically modulated p53 and adjusted Bcl-2 in striatum compared to TMPP and BO monotherapies, respectively. These results demonstrated a synergistic effect of TMPP + BO in protecting against hypothalamus and striatum in rats from ischemia-reperfusion injury and suggested that the mechanism involved shifting neurons from harmful apoptosis to protective autophagy and reducing neuronal [Ca2+]i.

MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles.

In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP) for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX). They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo.

Redox-triggered activation of nanocarriers for mitochondria-targeting cancer chemotherapy.

The importance of mitochondrial delivery of an anticancer drug to cancer cells has been recognized to improve therapeutic efficacy. The introduction of lipophilic cations, such as triphenylphosphonium (TPP), onto the surface of nanocarriers was utilized to target mitochondria via strong electrostatic interactions between positively charged TPP and the negatively charged mitochondrial membrane. However, the highly positive charge nature of TPP leads to rapid clearance from the blood, decrease of circulation lifetime, and nonspecific targeting of mitochondria of cells. Here, we report a strategy for improving the anticancer efficacy of paclitaxel via redox triggered intracellular activation of mitochondria-targeting. The lipid-polymer hybrid nanoparticles (LPNPs) are composed of poly(d,l-lactide-co-glycolide) (PLGA), a TPP-containing amphiphilic polymer (C18-PEG2000-TPP) and a reduction-responsive amphiphilic polymer (DLPE-S-S-mPEG4000). The charges of TPP in LPNPs were almost completely shielded by surface coating of a PEG4000 layer, ensuring high tumor accumulation. After uptake by cancer cells, the surface charges of LPNPs were recovered due to the detachment of PEG4000 under intracellular reductive conditions, resulting in rapid and precise localization in mitochondria. This kind of simple, easy and practicable mitochondria-targeting nanoplatform showed high anticancer activity, and the activatable strategy is valuable for developing a variety of nanocarriers for application in the delivery of other drugs.

The Synergic Effect of Tetramethylpyrazine Phosphate and Borneol for Protecting Against Ischemia Injury in Cortex and Hippocampus Regions by Modulating Apoptosis and Autophagy.

This study aimed to investigate the synergic effects of tetramethylpyrazine phosphate (TMPP) and borneol (BO) for protecting against ischemia in the cortex and hippocampus. A rat model of global cerebral ischemia-reperfusion (GCIR) was induced by four-vessel occlusion. The results showed that TMPP (13.3 mg/kg), BO (0.16 g/kg), and their combination improved the ultrastructure of neurons, reduced the apoptosis index, and reduced the intracellular calcium content in both the cortex and hippocampus. TMPP and the combined treatment increased cortex autophagy by modulating phosphorylated adenosine monophosphate-activated protein kinase (pAMPK) in the pAMPK-mammalian target of rapamycin (mTOR)-Unc-51-like kinase 1 (ULK1) signaling pathway, whereas BO only regulated ULK1. Moreover, BO increased neuron autophagy in the hippocampus by modulating mTOR, whereas TMPP targeted both mTOR and Beclin1. Similarly, the combination targeted both pAMPK and Beclin1. All three treatments decreased the expression of p53 and caspase-3 in the two areas. Additionally, TMPP and the combined therapy regulated Bax and Bcl-2. These results demonstrated the synergic effects between TMPP and BO for treating ischemia-reperfusion injury in the cortex and hippocampus regions. Their neuroprotective effects could be partly attributed to switching from apoptosis to protective autophagy. Additionally, the potential mechanism triggering this switching could be ascribed to the reduction of intracellular calcium content.

Near-infrared light-triggered theranostics for tumor-specific enhanced multimodal imaging and photothermal therapy.

The major challenge in current clinic contrast agents (CAs) and chemotherapy is the poor tumor selectivity and response. Based on the self-quench property of IR820 at high concentrations, and different contrast effect ability of Gd-DOTA between inner and outer of liposome, we developed "bomb-like" light-triggered CAs (LTCAs) for enhanced CT/MRI/FI multimodal imaging, which can improve the signal-to-noise ratio of tumor tissue specifically. IR820, Iohexol and Gd-chelates were firstly encapsulated into the thermal-sensitive nanocarrier with a high concentration. This will result in protection and fluorescence quenching. Then, the release of CAs was triggered by near-infrared (NIR) light laser irradiation, which will lead to fluorescence and MRI activation and enable imaging of inflammation. In vitro and in vivo experiments demonstrated that LTCAs with 808 nm laser irradiation have shorter T1 relaxation time in MRI and stronger intensity in FI compared to those without irradiation. Additionally, due to the high photothermal conversion efficiency of IR820, the injection of LTCAs was demonstrated to completely inhibit C6 tumor growth in nude mice up to 17 days after NIR laser irradiation. The results indicate that the LTCAs can serve as a promising platform for NIR-activated multimodal imaging and photothermal therapy.

Selenylsulfide Bond-Launched Reduction-Responsive Superparamagnetic Nanogel Combined of Acid-Responsiveness for Achievement of Efficient Therapy with Low Side Effect.

With the objective to achieve in-between reduction-responsive drug release, selenylsulfide bond was first explored as a reduction cleavable linkage, compared with the most commonly employed disulfide and diselenide bonds. The reductive nanogel, with a combination of superparamagnetic and acid responsiveness, was fabricated. The expected release profiles were testified. Cytotoxicity assays illustrated the remarkable inhibition to the growth of HeLa cells, in contrast, high tolerance to L02 cells. In vivo investigation exhibited the obvious shrinkage in tumor but a healthy appearance. Hematoxylin-eosin staining and histological examination revealed the lower toxicity. The complex nanogels would have appeared highly promising in cancer therapy.