Driving forces of hydrological health and multifractal response of fish habitat in regulated rivers.

Climate change and anthropogenic activities are major influences on the hydrological cycle, further altering river hydrological health. However, the characteristics of the forces in driving the variations of hydrological health at long-short time scales (annual, seasonal, monthly), as well as the potential impacts of these variations on aquatic habitats, remain unclear. In this study, the flow threshold method was introduced to identify the inherent characteristics of river hydrological health degree (RHD) evolution in the upper reaches of the Yangtze River (URYR) through the extreme-point symmetric modal decomposition (ESMD) method and range of variation approach (RVA). The RHD under unregulated conditions was reconstructed to quantify the impacts of anthropogenic activities and climate change. Subsequently, a multifractal model was proposed to establish the relationship between RHD and habitat-weighted usage area (WUA) during the spawning period of the Four Famous Major Carps, aiming to analyze the response mechanisms of habitat conditions to RHD fluctuations. The results showed that the RHD in the URYR exhibited degradation characteristics, experiencing a moderate change with a value of 0.44. Climate change was identified as the dominant factor causing the annual-scale decline in RHD, with an average impact weight of 62.9%. At the annual scale, Anthropogenic activities exacerbate (-3.4), counteract (20.1), and counteract (20.5) the adverse climatic impacts at Yichang, Cuntan, and Zhutuo stations, respectively. Additionally, the effect of human activities during the flood season is slight, with the most favorable and unfavorable impacts occurring in December (50.7) at the Zhutuo station and in October (-27.2) at the Yichang station. Under the influence of driving forces, the multifractal correlation of the RHD-WUA system tended to homogenized as the time window increased, indicating the presence of potential nonlinear dependence, asymmetric fractal characteristics, and positive-to-negative persistence transitions. Therefore, modeling river health considering fish habitat cannot be limited to linear paradigms. The findings provide valuable insights for the management and restoration of aquatic ecosystems.

Tumor Reoxygenation and Blood Perfusion Enhanced Photodynamic Therapy using Ultrathin Graphdiyne Oxide Nanosheets.

Both diffusion-limited and perfusion-limited hypoxia are associated with tumor progression, metastasis, and the resistance to therapeutic modalities. A strategy that can efficiently overcome both types of hypoxia to enhance the efficacy of cancer treatment has not been reported yet. Here, it is shown that by using biomimetic ultrathin graphdiyne oxide (GDYO) nanosheets, both types of hypoxia can be simultaneously addressed toward an ideal photodynamic therapy (PDT). The GDYO nanosheets, which are oxidized and exfoliated from graphdiyne (GDY), are able to efficiently catalyze water oxidation to release O2 and generate singlet oxygen (1O2) using near-infrared irradiation. Meanwhile, GDYO nanosheets also exhibit excellent light-to-heat conversion performance with a photothermal conversion efficiency of 60.8%. Thus, after the GDYO nanosheets are coated with iRGD peptide-modified red blood membrane (i-RBM) to achieve tumor targeting, the biomimetic GDYO@i-RBM nanosheets can simultaneously enhance tumor reoxygenation and blood perfusion for PDT. This study provides new insights into utilizing novel water-splitting materials to relieve both diffusion- and perfusion-limited hypoxia for the development of a novel therapeutic platform.

PVP intercalated metallic WSe2 as NIR photothermal agents for efficient tumor ablation.

Transition metal dichalogenides (TMDCs) with unique layered structures hold promising potential as transducers for photothermal therapy. However, the low photothermal conversion efficiency and poor stability in some cases limit their practical applications. Herein, we demonstrate the fabrication of ultrathin homogeneous hybridized TMDC nanosheets and their use for highly efficient photothermal tumor ablation. In particular, the nanosheets were composed of metallic WSe2 intercalated with polyvinylpyrrolidone (PVP), which was facilely prepared through a solvothermal process from the mixture of selenourea crystals, WCl6 powder along with PVP polymeric nanogel. Our characterizations revealed that the obtained nanosheets exhibited excellent photothermal conversion efficiency, therapeutic demonstration with improved biocompatibility and physiological stability attributing to the combined merits of metallic phase of WSe2 and hydrophilic PVP insertion. Both the histological analysis of vital organs and in vitro/in vivo tests confirmed the nanosheets as actively effective and biologically safe in this phototherapeutic technique. Findings from this non-invasive experiment clearly emphasize the explorable therapeutic efficacy of the layered-based hybrid agents in future cancer treatment planning procedures.

Ultrathin Polypyrrole Nanosheets via Space-Confined Synthesis for Efficient Photothermal Therapy in the Second Near-Infrared Window.

Extensive efforts have been devoted to synthesizing photothermal agents (PTAs) that are active in the first near-infrared (NIR) region (650-950 nm). However, PTAs for photothermal therapy in the second NIR window (1000-1350 nm) are still rare. Here, it is shown that two-dimensional ultrathin polypyrrole (PPy) nanosheets prepared via a novel space-confined synthesis method could exhibit unique broadband absorption with a large extinction coefficient of 27.8 L g-1 cm-1 at 1064 nm and can be used as an efficient PTA in the second NIR window. This unique optical property is attributed to the formation of bipolaron bands in highly doped PPy nanosheets. The measured prominent photothermal conversion efficiency could achieve 64.6%, surpassing previous PTAs that are active in the second NIR window. Both in vitro and in vivo studies reveal that these ultrathin PPy nanosheets possess good biocompatibility and notable tumor ablation ability in the second NIR window. Our study highlights the potential of ultrathin two-dimensional polymers with unique optical properties in biomedical applications.

Enzyme Degradable Hyperbranched Polyphosphoester Micellar Nanomedicines for NIR Imaging-Guided Chemo-Photothermal Therapy of Drug-Resistant Cancers.

Multidrug resistance (MDR) is the major cause for chemotherapy failure, which constitutes a formidable challenge in the field of cancer therapy. The synergistic chemo-photothermal treatment has been reported to be a potential strategy to overcome MDR. In this work, rationally designed enzyme-degradable, hyperbranched polyphosphoester nanomedicines were developed for reversing MDR via the codelivery of doxorubicin and IR-780 (hPPEDOX&IR) as combined chemo-photothermal therapy. The amphiphilic hyperbranched polyphosphoesters with phosphate bond as the branching point were synthesized via a simple but robust one-step polycondensation reaction. The self-assembled hPPEDOX&IR exhibited good serum stability, sustained release, preferable tumor accumulation, and enhanced drug influx of doxorubicin in resistant MCF-7/ADR cells. Moreover, the degradation of hPPEDOX&IR was accelerated in the presence of alkaline phosphatase, which was overexpressed in various cancers, resulting in the fast release of encapsulated doxorubicin. The enzyme-degradable polymer generated synergistic chemo-photothermal cytotoxicity against MCF-7/ADR cells and, thus, the efficient ablation of DOX-resistant tumor without regrowth. This delivery system may open a new avenue for codelivery of chemo- and photothermal therapeutics for MDR tumor therapy.

Tumor Acidity/NIR Controlled Interaction of Transformable Nanoparticle with Biological Systems for Cancer Therapy.

Precisely controlling the interaction of nanoparticles with biological systems (nanobio interactions) from the injection site to biological targets shows great potential for biomedical applications. Inspired by the ability of nanoparticles to alter their physicochemical properties according to different stimuli, we explored the tumor acidity and near-infrared (NIR) light activated transformable nanoparticle DATAT-NPIR&DOX. This nanoparticle consists of a tumor acidity-activated TAT [the TAT lysine residues' amines was modified with 2,3-dimethylmaleic anhydride (DA)], a flexible chain polyphosphoester core coencapsulated a NIR dye IR-780, and DOX (doxorubicin). The physicochemical properties of the nanoparticle can be controlled in a stepwise fashion using tumor acidity and NIR light, resulting in adjustable nanobio interactions. The resulting transformable nanoparticle DATAT-NPIR&DOX efficiently avoids the interaction with mononuclear phagocyte system (MPS) ("stealth" state) due to the masking of the TAT peptide during blood circulation. Once it has accumulated in the tumor tissues, DATAT-NPIR&DOX is reactivated by tumor acidity and transformed into the "recognize" state in order to promote interaction with tumor cells and enhance cellular internalization. Then, this nanoparticle is transformed into "attack" state under NIR irradiation, achieving the supersensitive DOX release from the flexible chain polyphosphoester core in order to increase the DOX-DNA interaction. This concept provides new avenues for the creation of transformable drug delivery systems that have the ability to control nanobio interactions.

Identification of a targeted ACSL4 inhibitor to treat ferroptosis-related diseases.

Ferroptosis is a form of iron-dependent, lipid peroxidation-driven regulatory cell death that has been implicated in the pathogenesis of multiple diseases, including organ injury, ischemia/reperfusion, and neurodegenerative diseases. However, inhibitors that directly and specifically target ferroptosis are not yet available. Here, we identify the compound AS-252424 (AS) as a potent ferroptosis inhibitor through kinase inhibitor library screening. Our results show that AS effectively inhibits lipid peroxidation and ferroptosis in both human and mouse cells. Mechanistically, AS directly binds to the glutamine 464 of ACSL4 to inhibit its enzymatic activity, resulting in the suppression of lipid peroxidation and ferroptosis. By using nanoparticle-based delivery systems, treatment with AS-loaded nanoparticles effectively alleviate ferroptosis-mediated organ injury in mouse models, including kidney ischemia/reperfusion injury and acute liver injury (ALI). Thus, our results identify that AS is a specific and targeted inhibitor of ACSL4 with remarkable antiferroptosis function, providing a potential therapeutic for ferroptosis-related diseases.

Copper(II)-Based Nano-Regulator Correlates Cuproptosis Burst and Sequential Immunogenic Cell Death for Synergistic Cancer Immunotherapy.

Immunogenic cell death (ICD) of tumor cells serves as a crucial initial signal in the activation of anti-tumor immune responses, holding marked promise in the field of tumor immunotherapy. However, low immunogenicity tumors pose challenges in achieving complete induction of ICD, thereby limiting the response rates of immunotherapy in clinical patients. The emergence of cuproptosis as a new form of regulated cell death has presented a promising strategy for enhanced immunotherapy of low immunogenic tumors. To trigger cuproptosis, copper-ionophore elesclomol (ES) had to be employed for the copper-transporting-mediated process. Herein, we proposed a copper(II)-based metal-organic framework nanoplatform (Cu-MOF) to facilitate a cooperative delivery of encapsulated ES and copper (ES-Cu-MOF) to induce cuproptosis burst and enhance ICD of fibrosarcoma. Our results showed that the ES-Cu-MOF nano-regulator could effectively release Cu2+ and ES in response to the intracellular environment, resulting in elevated mitochondrial ROS generation and initiated cuproptosis of tumor cells. Furthermore, sequential ICDs were significantly triggered via the ES-Cu-MOF nano-regulator to activate the anti-tumor immune response. The results of tumor inhibition experiment indicated that the nano-regulator of ES-Cu-MOF obviously accumulated in the tumor site, inducing ICD for dendritic cell activation. This enabled an increased infiltration of cytotoxic CD8+ T cells and consequently enhanced antitumor immune responses for successfully suppressing fibrosarcoma growth. Thus, the copper(II)-based metal-organic framework nano-regulator offered a promising approach for inducing cuproptosis and cuproptosis-stimulated ICD for cancer immunotherapy.

Role of pyroptosis in the pathogenesis and treatment of diseases.

Programmed cell death (PCD) is regarded as a pathological form of cell death with an intracellular program mediated, which plays a pivotal role in maintaining homeostasis and embryonic development. Pyroptosis is a new paradigm of PCD, which has received increasing attention due to its close association with immunity and disease. Pyroptosis is a form of inflammatory cell death mediated by gasdermin that promotes the release of proinflammatory cytokines and contents induced by inflammasome activation. Recently, increasing evidence in studies shows that pyroptosis has a crucial role in inflammatory conditions like cardiovascular diseases (CVDs), cancer, neurological diseases (NDs), and metabolic diseases (MDs), suggesting that targeting cell death is a potential intervention for the treatment of these inflammatory diseases. Based on this, the review aims to identify the molecular mechanisms and signaling pathways related to pyroptosis activation and summarizes the current insights into the complicated relationship between pyroptosis and multiple human inflammatory diseases (CVDs, cancer, NDs, and MDs). We also discuss a promising novel strategy and method for treating these inflammatory diseases by targeting pyroptosis and focus on the pyroptosis pathway application in clinics.

Compartmentalized Nano-MOFs as Co-delivery Systems for Enhanced Antitumor Therapy.

Therapeutic bioactive macromolecules hold great promise in cancer therapy, but challenges such as low encapsulation efficiency and susceptibility to inactivation during the targeted co-delivery hinder their widespread applications. Compartmentalized nano-metal-organic frameworks (nMOFs) can easily load macromolecules in the innermost layer, protect them from the outside environment, and selectively release them in the target location after stimulation, showing great potential in the co-delivery of biomacromolecules. Herein, the rationally designed (GOx + CAT)/ZIF-8@BSATPZ/ZIF-8 (named GCZ@BTZ) nMOFs with compartmentalized structures are employed to deliver cascaded enzymes and the chemotherapeutic drug tirapazamine (TPZ)-conjugated bovine serum albumin (BSATPZ). Benefiting from the compartmentalized structure and protective shell, the GCZ@BTZ system is stable during blood circulation and preferentially accumulates in the tumor. Furthermore, in response to the acidic tumor environment, GCZ@BTZ effectively released the loading enzymes and BSATPZ. Along with the tumor starvation caused by depletion of glucose, cascaded reactions could also contribute to the enhancement of tumor hypoxia, which further activated BSATPZ-based chemotherapy. Notably, in the mouse tumor models, GCZ@BTZ treatment significantly inhibits tumor survival and metastasis. Such a compartmentalized nMOF delivery system presents a promising avenue for the efficient delivery of bioactive macromolecules.

Nanomedicines with high drug availability and drug sensitivity overcome hypoxia-associated drug resistance.

Tumor hypoxia heterogeneity, a hallmark of the tumor microenvironment, confers resistance to conventional chemotherapy due to insufficient drug availability and drug sensitivity in hypoxic regions. To overcome these challenges, we develope a nanomedicine, NPHPaPN, constructed with hyaluronic acid (HA) grafted with cisplatin prodrug and PEG-azobenzene for hypoxia-responsive PEG shell deshielding and loaded with a DNA damage repair inhibitor (NERi). After arriving at the tumor site, NPHPaPN deshields the PEG shell in response to hypoxia due to the enzymolysis of azobenzene and thus exposes HA. The exposed HA binds to the highly expressed CD44 on cisplatin-resistant tumor cells and mediates drug internalization, thus increasing drug availability to hypoxic tumor cells. After intracellular hyaluronidase-mediated cleavage, the HA NPs release the cisplatin prodrug and NERi, and cause enhanced DNA damage and consequent cell death, thus enhancing the drug sensitivity of hypoxic tumor cells. Eventually, NPHPaPN achieves distinct tumor growth suppression with an ∼84.4% inhibition rate.

Nano-enabled coordination platform of bismuth nitrate and cisplatin prodrug potentiates cancer chemoradiotherapy via DNA damage enhancement.

The combination of chemotherapy and radiotherapy (chemoradiotherapy) is a promising strategy, extensively studied and applied clinically. Meanwhile, radiosensitizers play an important role in improving clinical radiotherapy therapeutic efficacy. There are still some disadvantages in practical applications, because radiosensitizers and drugs are difficult to deliver spatio-temporally to tumor sites and work simultaneously with low efficiency for DNA damage and repair inhibition, leading to an inferior synergistic effect. Herein, a suitable radiosensitizer of nano-enabled coordination platform (NP@PVP) with bismuth nitrate and cisplatin prodrug is developed by a simple synthetic route to improve the effectiveness of chemo-radiation synergistic therapy. When NP@PVP is internalized by a tumor cell, the bismuth in NP@PVP can sensitize radiation therapy (RT) by increasing the amount of reactive oxygen species generation to enhance DNA damage after X-ray radiation; meanwhile, the cisplatin in NP@PVP can inhibit DNA damage repair with spatio-temporal synchronization. NP@PVP is demonstrated to exhibit higher sensitization enhancement ratio (SER) of 2.29 and excellent tumor ablation capability upon irradiation in vivo in comparison with cisplatin (SER of 1.78). Our strategy demonstrates that the RT sensitization effect of bismuth and cisplatin based NP@PVP has great anticancer potential in chemo-radiation synergistic therapy, which is promising for clinical application.

Facile syntheses of conjugated polymers for photothermal tumour therapy.

Development of photothermal materials which are able to harness sunlight and convert it to thermal energy seems attractive. Besides carbon-based nanomaterials, conjugated polymers are emerging promising photothermal materials but their facile syntheses remain challenging. In this work, by modification of a CBT-Cys click condensation reaction and rational design of the starting materials, we facilely synthesize conjugated polymers poly-2-phenyl-benzobisthiazole (PPBBT) and its dihexyl derivative with good photothermal properties. Under the irradiation of either sunlight-mimicking Xe light or near-infrared laser, we verify that PPBBT has comparable photothermal heating-up speed to that of star material single-wall carbon nanotube. Moreover, PPBBT is used to fabricate water-soluble NPPPBBT nanoparticles which maintain excellent photothermal properties in vitro and photothermal therapy effect on the tumours exposed to laser irradiation. We envision that our synthetic method provides a facile approach to fabricate conjugated polymers for more promising applications in biomedicine or photovoltaics in the near future.

Near-Infrared II Phototherapy Induces Deep Tissue Immunogenic Cell Death and Potentiates Cancer Immunotherapy.

The deep and inner beds of solid tumors lack lymphocytic infiltration and are subjected to various immune escape mechanisms. Reversing immunosuppression deep within the tumor is vital in clinical cancer therapy, however it remains a huge challenge. In this work, we have demonstrated the use of a second window near-infrared (NIR(II)) photothermal treatment to trigger more homogeneous and deeper immunogenic cancer cell death in solid tumors, thereby eliciting both innate and adaptive immune responses for tumor control and metastasis prevention. Specifically, photothermal transducers with similar components, structures, and photothermal conversion efficiencies, but different absorptions in red light, NIR(I), and NIR(II) biowindows, were constructed by controlling the self-assembly of gold nanoparticles on fluidic liposomes. In vitro, photothermal treatments induced immunogenic cell death (ICD) that were accompanied by the release of damage-associated molecular patterns (DAMPs) regardless of the wavelength of incident lasers. In vivo, NIR(II) light resulted in a more homogeneous release and distribution of DAMPs in the deeper parts of the tumors. With the induction of ICD, NIR(II) photothermal therapy simultaneously triggered both innate and adaptive immune responses and enabled efficient tumor control with 5/8 of the mice remaining tumor-free in the cancer vaccination assay. Additionally, the NIR(II) photothermal treatment in combination with checkpoint blockade therapy exerted long-term tumor control over both primary and distant tumors. Finally, using systemically administered two-dimensional polypyrrole nanosheets as a NIR(II) transducer, we achieved striking therapeutic effects against whole-body tumor metastasis via a synergistic photothermal-immunological response.

Nanoclustered Cascaded Enzymes for Targeted Tumor Starvation and Deoxygenation-Activated Chemotherapy without Systemic Toxicity.

Intratumoral glucose depletion-induced cancer starvation represents an important strategy for anticancer therapy, but it is often limited by systemic toxicity, nonspecificity, and adaptive development of parallel energy supplies. Herein, we introduce a concept of cascaded catalytic nanomedicine by combining targeted tumor starvation and deoxygenation-activated chemotherapy for an efficient cancer treatment with reduced systemic toxicity. Briefly, nanoclustered cascaded enzymes were synthesized by covalently cross-linking glucose oxidase (GOx) and catalase (CAT) via a pH-responsive polymer. The release of the enzymes can be first triggered by the mildly acidic tumor microenvironment and then be self-accelerated by the subsequent generation of gluconic acid. Once released, GOx can rapidly deplete glucose and molecular oxygen in tumor cells while the toxic side product, i.e., H2O2, can be readily decomposed by CAT for site-specific and low-toxicity tumor starvation. Furthermore, the enzymatic cascades also created a local hypoxia with the oxygen consumption and reductase-activated prodrugs for an additional chemotherapy. The current report represents a promising combinatorial approach using cascaded catalytic nanomedicine to reach concurrent selectivity and efficiency of cancer therapeutics.

Au nanoparticles with enzyme-mimicking activity-ornamented ZIF-8 for highly efficient photodynamic therapy.

The tumor hypoxic microenvironment (THME) has a profound impact on tumor progression, and modulation of the THME has become an essential strategy to promote photodynamic therapy (PDT). Here, an oxygen self-supplied nanodelivery system that is based on nanometal-organic frameworks (nMOFs) with embedded AuNPs (Au@ZIF-8) on the nMOF surface as a catalase (CAT)-like nanozyme and encapsulating Ce6 inside as a photosensitizer was found to mitigate tumor hypoxia and reinforce PDT. As soon as Au@ZIF-8 reaches the tumor site, the AuNP nanozyme can catalyze excessive H2O2 to produce O2 to alleviate tumor hypoxia, promoting the production of 1O2 with strong toxicity toward tumor cells under irradiation. Our study demonstrates that nMOFs embellished with a nanozyme have great potential for overcoming the THME for cancer therapeutics, which provides a facile strategy for accurate bioimaging and cancer therapy in vivo.

Hierarchical Multiplexing Nanodroplets for Imaging-Guided Cancer Radiotherapy via DNA Damage Enhancement and Concomitant DNA Repair Prevention.

Clinical success of cancer radiotherapy is usually impeded by a combination of two factors, i.e., insufficient DNA damage and rapid DNA repair during and after treatment, respectively. Existing strategies for optimizing the radiotherapeutic efficacy often focus on only one facet of the issue, which may fail to function in the long term trials. Herein, we report a DNA-dual-targeting approach for enhanced cancer radiotherapy using a hierarchical multiplexing nanodroplet, which can simultaneously promote DNA lesion formation and prevent subsequent DNA damage repair. Specifically, the ultrasmall gold nanoparticles encapsulated in the liquid nanodroplets can concentrate the radiation energy and induce dramatic DNA damage as evidenced by the enhanced formation of γ-H2AX foci as well as in vivo tumor growth inhibition. Additionally, the ultrasound-triggered burst release of oxygen may relieve tumor hypoxia and fix the DNA radical intermediates produced by ionizing radiation, prevent DNA repair, and eventually result in cancer death. Finally, the nanodroplet platform is compatible with fluorescence, ultrasound, and magnetic resonance imaging techniques, allowing for real-time in vivo imaging-guided precision radiotherapy in an EMT-6 tumor model with significantly enhanced treatment efficacy. Our DNA-dual-targeting design of simultaneously enhancing DNA damage and preventing DNA repair presents an innovative strategy to effective cancer radiotherapy.

Encapsulation of cisplatin in a pegylated calcium phosphate nanoparticle (CPNP) for enhanced cytotoxicity to cancerous cells.

HYPOTHESIS: Exchange of the chloride ion (Cl-) ligands of cisplatin with carboxylates is widely used in fabricating cisplatin loaded nanoparticles for improved cancer therapy. However, the dynamic exchange may cause premature cisplatin release and even disintegration of the nanoparticles in Cl--containing medium such as in plasma. Molecules bearing carboxylates are capable of mediating the mineralization process of calcium phosphate; therefore, it is possible to overcome the disadvantage by sequestering cisplatin in a calcium phosphate nanoparticle (CPNP). EXPERIMENTS: With the hypothesis, precipitation reaction of calcium nitrate and disodium hydrogen phosphate was performed in a solution of poly(ethylene glycol)-poly(acrylic acid) block copolymers with their carboxylates partly conjugated with cisplatin. Then, structure, physicochemical properties, and bioactivity of the product were carefully investigated with multiple characterization methods. FINDINGS: It was revealed a pegylated, cisplatin encapsulated CPNP was prepared; and with appropriate mole ratio of cisplatin to carboxylates, the nanoparticle encapsulated cisplatin efficiently (>90%), was stable and almost entirely prevented the cisplatin release in Cl--containing medium at pH 7.4 but released them in an acidic condition, and showed moderately and greatly enhanced cytotoxicities to the lung cancer cell line A549 and its cisplatin resistance form A549R respectively in comparison with the free cisplatin.

Ruthenium nitrosyl functionalized graphene quantum dots as an efficient nanoplatform for NIR-light-controlled and mitochondria-targeted delivery of nitric oxide combined with photothermal therapy.

A mitochondria-targeting nanoplatform for near-infrared-light-controlled release of nitric oxide accompanied by photothermal therapy was developed, which consists of ruthenium nitrosyl functionalized N-doped graphene quantum dots and a triphenylphosphonium moiety. The nanoplatform demonstrated both in vitro and in vivo anti-tumor efficacy upon irradiation with 808 nm light.

PEGylated hyperbranched polyphosphoester based nanocarriers for redox-responsive delivery of doxorubicin.

Redox-responsive polymers exhibit great potential as drug delivery systems. Herein, a redox-responsive PEGylated hyperbranched polyphosphoester (PPE) was synthesized through (A2 + B3) type polycondensation. The obtained hyperbranched PPE can self-assemble into nanoparticles in water. The biocompatibility of the nanoparticles was evaluated. The hydrophobic chemotherapy drug doxorubicin (DOX) can be efficiently encapsulated into the obtained nanoparticles. Such DOX-loaded nanoparticles exhibited excellent stability due to the PEGylation, and showed redox-responsive drug release behavior. In addition, flow cytometric analyses demonstrated that the redox-responsive nanoparticles could be efficiently internalized into the human breast cancer cell line MDA-MB-231, and intracellular glutathione enhanced the intracellular drug release from the redox-responsive hyperbranched PPE based nanoparticles. Therefore, such nanoparticles resulted in the enhanced inhibition of tumor cell growth, suggesting the potential of redox-responsive PEGylated hyperbranched PPE in anticancer drug delivery.