Injectable nano-composite hydrogels based on hyaluronic acid-chitosan derivatives for simultaneous photothermal-chemo therapy of cancer with anti-inflammatory capacity.

Nowadays, the photothermal therapy (PTT) has received widespread attention and research by rapidly killing tumors with local high temperature. However, due to the irregular edges of tumor and the blurred boundary between normal and necrotic tissues, the desirable treatment cannot be achieved by the single PTT, and excessive heat will cause serious inflammation in local tissues. Herein, an injectable composite hydrogel is prepared by the oxidized hyaluronic acid (OHA) and hydroxypropyl chitosan (HPCS) via the imine bonds, which is employed as the delivery substrate for functional substances. In the gel medium, the mesoporous polydopamine (MPDA) nanoparticles are incorporated as the high efficiency photothermal agent and a reservoir of DOX, which can achieve the good photothermal conversion performance and pulsed drug release. Besides, the addition of the curcumin-cyclodextrin host-guest inclusion complex (CUR@NH2-CD) in the composite hydrogel could reduce the inflammation caused by PTT. The composite hydrogel shows favorable the Hepa1-6 tumor inhibition in vivo by virtue of the comprehensive effect of the admired photothermal efficacy of MPDA, chemotherapy of DOX and anti-inflammatory of CUR. It can be predicted that the composite hydrogel has a broad prospect in the field of comprehensive therapy for tumor.

Recent advances in erythrocyte membrane-camouflaged nanoparticles for the delivery of anti-cancer therapeutics.

INTRODUCTION: Red blood cell (or erythrocyte) membrane-camouflaged nanoparticles (RBC-NPs) not only have a superior circulation life and do not induce accelerated blood clearance but also possess special functions, which offers great potential in cancer therapy. AREAS COVERED: This review focuses on the recent advances of RBC-NPs for delivering various agents to treat cancers in light of their vital role in improving drug delivery. Meanwhile, the construction and in vivo behavior of RBC-NPs are discussed to provide an in-depth understanding of the basis of RBC-NPs for improved cancer drug delivery. EXPERT OPINION: Although RBC-NPs are quite prospective in delivering anti-cancer therapeutics, they are still in their infancy stage and many challenges need to be overcome for successful translation into the clinic. The preparation and modification of RBC membranes, the optimization of coating methods, the scale-up production and the quality control of RBC-NPs, and the drug loading and release should be carefully considered in the clinical translation of RBC-NPs for cancer therapy.

Extracellular matrix-degrading STING nanoagonists for mild NIR-II photothermal-augmented chemodynamic-immunotherapy.

Regulation of stimulator of interferon genes (STING) pathway using agonists can boost antitumor immunity for cancer treatment, while the rapid plasma clearance, limited membrane permeability, and inefficient cytosolic transport of STING agonists greatly compromise their therapeutic efficacy. In this study, we describe an extracellular matrix (ECM)-degrading nanoagonist (dNAc) with second near-infrared (NIR-II) light controlled activation of intracellular STING pathway for mild photothermal-augmented chemodynamic-immunotherapy of breast cancer. The dNAc consists of a thermal-responsive liposome inside loading with ferrous sulfide (FeS2) nanoparticles as both NIR-II photothermal converters and Fenton catalysts, 2'3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) as the STING agonist, and an ECM-degrading enzyme (bromelain) on the liposome surface. Mild heat generated by dNAc upon NIR-II photoirradiation improves Fenton reaction efficacy to kill tumor cells and cause immunogenic cell death (ICD). Meanwhile, the generated heat triggers a controlled release of cGAMP from thermal-responsive liposomes to active STING pathway. The mild photothermal activation of STING pathway combined with ICD promotes anti-tumor immune responses, which leads to improved infiltration of effector T cells into tumor tissues after bromelain-mediated ECM degradation. As a result, after treatment with dNAc upon NIR-II photoactivation, both primary and distant tumors in a murine mouse model are inhibited and the liver and lung metastasis are effectively suppressed. This work presents a photoactivatable system for STING pathway and combinational immunotherapy with improved therapeutic outcome.

Polydopamine Nanoparticles for Deep Brain Ablation via Near-Infrared Irradiation.

Local resection or ablation remains an important approach to treat drug-resistant central neurological disease. Conventional surgical approaches are designed to resect the diseased tissues. The emergence of photothermal therapy (PTT) offers a minimally invasive alternative. However, their poor penetration and potential off-target effect limit their clinical application. Here, polydopamine nanoparticles (PDA-NPs) were prepared and characterized. Studies were performed to evaluate whether PDA-NPs combined with near-infrared (NIR) light can be used to ablate deep brain structures in vitro and in vivo. PDA-NPs were prepared with a mean diameter of ∼150 nm. The particles show excellent photothermal conversion efficiency. PDA-NPs did not show remarkable cytotoxicity against neuronal-like SH-SY5Y cell lines. However, it can cause significant cell death when combined with NIR irradiation. Transcranial NIR irradiation after PDA-NPs administration induced enhanced local hyperthermia as compared with NIR alone. Local temperature exceeded 60 °C after 6 min of irradiation plus PDA while it can only reach 48 °C with NIR alone. PTT with PDA (10 mg/mL, 3 µL) and NIR (1.5 W/cm2) can ablate deep brain structures precisely with an ablation volume of ∼6.5 mm3. Histological analysis confirmed necrosis and apoptosis in the targeted area. These results demonstrate the potential of NP-assisted PTT for the treatment against nontumorous central neurological diseases.

Obacunone attenuates high glucose-induced oxidative damage in NRK-52E cells by inhibiting the activity of GSK-3ß.

Hyperglycemia-induced proximal tubule injury plays a critical role in the pathogenesis of diabetic nephropathy (DN). Attenuating high glucose (HG)-induced oxidative damage in renal tubular epithelial cells has been documented to ameliorate DN. Obacunone (OB), a natural bioactive compound isolated from the Rutaceae family, has been demonstrated to possess various pharmacological effects with low toxicity. However, the role of OB in DN has not yet been investigated. To explore the influence of OB on oxidative damage that is induced by HG and its potential mechanisms of action, we set up a high glucose model and induced oxidative damage in NRK-52E cells. OB could protect the NRK-52E cells from the HG-induced decrease of cell viability and the accumulation of ROS. The protective effects of OB were associated with its ability to increase the levels of antioxidants (SOD, GSH and CAT), inhibit the production of ROS, and stabilize the mitochondrial membrane potential. In addition, OB significantly downregulated the activity of GSK-3ß, enhanced the nuclear translocation of Nrf2 and increased the mRNA expression of the Nrf2-driven genes NQO-1 and HO-1 in HG-treated cells. OB also decreased the release of cytochrome c from the mitochondria to the cytosol and inhibited the activation of caspase-3 in HG-treated cells. Pretreatment with a GSK-3ß activator blocked the protective effects of OB, while pretreatment with a GSK-3ß inhibitor yielded opposite results. These findings indicate that the renoprotective effects of OB against HG-induced oxidative damage in NRK-52E cells may be mediated by its ability to inhibit oxidative stress and mitochondrial dysfunction through the GSK-3ß signaling pathway.

Autophagy upregulation promotes macrophages to escape mesoporous silica nanoparticle (MSN)-induced NF-κB-dependent inflammation.

BACKGROUND: Our previous studies (Int J Nanomed 10:22, 2015) have indicated that a single large dose of mesoporous silica nanoparticles (MSNs) can induce severe and selective nephrotoxicity, which is closely related to inflammation mediated by the NF-κB pathway. However, the effect of MSNs on other organs and the interactions of nanomaterials with biological systems remain rudimentary. OBJECTIVE: This study aimed to clarify the biological behaviour and influence of MSNs on macrophages. METHODS: The mice received a single intraperitoneal injection of a suspension of 150, 300 of 600 mg/kg MSNs, and RAW 264.7 cells were treated with MSNs at various concentrations and times. Cell viability was determined by MTT assay and LDH release assay. The NF-κB pathway and the target proinflammatory cytokines IL-1ß and TNF-α were determined by western blotting or ELISA. Autophagy is considered as an emerging mechanism of nanomaterials. So the autophagic ultrastructural analysis, the determination of Beclin-1 and LC3 expression, and the calculation of LC3II dots were employed to verify autophagy activation. In addition, RNA interference, autophagy agonist and inhibitor were used to explore the role of autophagy in inflammation. RESULTS: The results indicated that MSNs are internalized into macrophages and induce cytotoxicity in a dose- and time-dependent manner. The NF-κB pathway, IL-1ß and TNF-α were induced and released by MSNs. The levels of Beclin-1 and LC3II dots were obviously up-regulated by MSNs, which indicated that autophagy was induced in the MSN-treated cells. Moreover, the enhanced autophagy can attenuate the inflammation mediated by the NF-κB pathway, whereas the inhibition of autophagy can contribute to inflammation. CONCLUSIONS: In summary, our results suggest that autophagy may be a possible protective factor in inflammation induced by MSNs in macrophages.