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Background: Although stimuli-responsive nanoplatforms were developed to deliver immunogenic cell death (ICD) inducers to enhance cancer immunotherapy, the complete release of ICD inducers into the tumor microenvironment (TME) was limited by the inadequate supplementation of endogenous stimulus (e.g., reactive oxygen species (ROS)). To address this issue, we synthesized a self-responsive nanomaterial with self-supplied ROS, which mainly consists of a ROS responsive moiety HPAP and cinnamaldehyde (CA) as the ROS-generating agent. The endogenous ROS can accelerate the degradation of HPAP in materials to release docetaxel (DTX, an ICD inducer). In intracellular acidic environment, the pH-sensitive acetal was cleaved to release CA. The released CA in turn induces the generation of more ROS through mitochondrial damage, resulting in amplified DTX release. Using this self-cycling and self-responsive nanomaterial as a carrier, DTX-loaded pH/ROS dual-responsive nanoparticles (DTX/FA-CA-Oxi-αCD NPs) were fabricated and evaluated in vitro and in vivo., Results: In vitro experiments validated that the NPs could be effectively internalized by FA-overexpressed cells and completely release DTX in acidic and ROS microenvironments to induce ICD effect. These NPs significantly blocked 4T1 cell migration and decreased cell invasion. In vivo experiments demonstrated that the tumor-targeted NPs significantly inhibited tumor growth and blocked tumor metastasis. More importantly, these NPs significantly improved immunotherapy through triggering effector T-cell activation and relieving the immunosuppressive state of the TME., Conclusions: Our results demonstrated that DTX/FA-CA-Oxi-αCD NPs displayed great potential in preventing tumor metastasis, inhibiting tumor growth, and improving the efficacy of anti-PD-1antibody., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Photodynamic therapy (PDT) has achieved continued success in the treatment of tumors, but its progress in the treatment of atherosclerosis has been limited, mainly due to the low tissue-penetration ability of the excitation light for photosensitizers., Methods: In this study, we designed a chemiexcited system producing singlet oxygen in an attempt to apply PDT for the treatment of atherosclerosis without the irradiation of external light. The system designed was polymeric nanoparticles (NPs) equipped with chemical fuel and photosensitizers, cross-linked with an Fe 3+ -catechol complex for stabilization and magnetic resonance imaging (MRI)., Results: The system (FeCNPs for short) accumulated effectively in plaques, providing persistent and enhanced T 1 -weighted contrast ability. FeCNPs also prevented progression of atherosclerosis via macrophage elimination, and obviously reduced plaque size and thickness revealed by T 1 -weighted MRI. Expression of CD68, MCP1, and TNFα was significantly reduced after treatment. However, low doses of FeCNPs exhibited better therapeutic efficacy than high doses. Furthermore, low-dose FeCNPs exhibited effective macrophage elimination in aortic arches and abdominal aortae, but inefficiency in the thoracic aorta, aortic hiatus, and aorta-iliac bifurcation., Conclusion: This study provides the first example of a combination of MRI and chemiexcited PDT for atherosclerosis, evidencing the effectiveness of PDT and providing significant pointers for developing nanotherapy on atherosclerosis., Competing Interests: The authors report no conflicts of interest in this work., (© 2022 Mu et al.)

Luteolin (Lut) is a natural flavonoid polyphenolic compound with multiple pharmacological activities, such as anti-oxidant, anti-inflammatory, and anti-tumor effects. However, the poor aqueous solubility and low bioactivity of Lut restrict its clinical translation. Herein, we developed a reactive oxygen species (ROS)-responsive nanoplatforms to improve the bioactivity of Lut. Folic acid (FA) was employed to decorate the nanoparticles (NPs) to enhance its targeting ability. The size of Lut-loaded ROS-responsive nanoparticles (Lut/Oxi-αCD NPs) and FA-modified Lut/Oxi-αCD NPs (Lut/FA-Oxi-αCD NPs) is 210.5 ± 6.1 and 196.7 ± 1.8 nm, respectively. Both Lut/Oxi-αCD NPs and Lut/FA-Oxi-αCD NPs have high drug loading (14.83 ± 3.50 and 16.37 ± 1.47%, respectively). In vitro cellular assays verified that these NPs could be efficiently internalized by 4T1 cells and the released Lut from NPs could inhibit tumor cells proliferation significantly. Animal experiments demonstrated that Lut/Oxi-αCD NPs, especially Lut/FA-Oxi-αCD NPs obviously accumulated at tumor sites, and inhibited tumor growth ∼3 times compared to the Lut group. In conclusion, the antitumor efficacy of Lut was dramatically improved by targeting delivery with the ROS-responsive nanoplatforms.

In recent times, co-delivery of therapeutics has emerged as a promising strategy for treating dreadful diseases such as cancer., Materials and Methods: In this study, we developed a novel nanocarrier based on bacterial magnetosomes (BMs) that co-loaded with siRNA and doxorubicin (DOX) using polyethyleneimine (PEI) as a cross-linker (BMs/DP/siRNA). The delivery efficiency of siRNA as well as the pH-responsive release of DOX, and synergistic efficacy of these therapeutics in vitro were systematically investigated., Results: The structure of DOX-PEI (DP) conjugates that synthesized via hydrazone bond formation was confirmed by 1H nuclear magnetic resonance (NMR). The in vitro release experiments showed that the DP conjugate (DOX-loading efficiency - 5.77%±0.08%) exhibited the long-term release behavior. Furthermore, the optimal BMs/DP/siRNA particle size of 107.2 nm and the zeta potential value of 31.1±1.0 mV facilitated enhanced cellular internalization efficiency. Moreover, the agarose gel electrophoresis showed that the co-delivery system could protect siRNA from degradation in serum and RNase A. In addition, the cytotoxicity assay showed that BMs/DP/siRNA could achieve an excellent synergistic effect compared to that of siRNA delivery alone. The acridine orange (AO)/ethidium bromide (EB) double staining assay also showed that BMs/DP/siRNA complex could induce cells in a stage of late apoptosis and nanocomplex located in the proximity of the nucleus., Conclusion: The combination of gene and chemotherapeutic drug using BMs is highly efficient, and the BMs/DP/siRNA would be a promising therapeutic strategy for the future therapeutics., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Breast cancer is the most common malignant tumor in women and is a big challenge to clinical treatment due to the high morbidity and mortality. The pH/ROS dual-responsive nanoplatforms may be an effective way to significantly improve the therapeutic efficacy of breast cancer. Herein, we report a docetaxel (DTX)-loaded pH/ROS-responsive NP that could achieve active targeting of cancer cells and selective and complete drug release for effective drug delivery. The pH/ROS-responsive NPs were fabricated using nanocarriers that consist of an ROS-responsive moiety (4-hydroxymethylphenylboronic acid pinacol ester, HPAP), cinnamaldehyde (CA, an aldehyde organic compound with anticancer activities) and cyclodextrin (α-CD). The NPs were loaded with DTX, modified with a tumor-penetration peptide (circular RGD, cRGD) and named DTX/RGD NPs. The cRGD could promote DTX/RGD NPs penetration into deep tumor tissue and specifically target cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, the pH-responsive acetal was cleaved to release CA in the lysosomal acidic environment. Meanwhile, the high ROS in tumor cells induced the disassembly of NPs with complete release of DTX. In vitro cellular assays verified that DTX/RGD NPs could be effectively internalized by 4T1 cells, obviously inducing apoptosis, blocking the cell cycle of 4T1 cells and consequently, killing tumor cells. In vivo animal experiments demonstrated that the NPs could target to the tumor sites and significantly inhibit the tumor growth in 4T1 breast cancer mice. Both in vitro and in vivo investigations demonstrated that DTX/RGD NPs could significantly improve the antitumor effect compared to free DTX. Thus, the DTX/RGD NPs provide a promising strategy for enhancing drug delivery and cancer therapy. [ABSTRACT FROM AUTHOR]

A main challenge in Heat-Assisted Magnetic Recording technology is the build-up of contaminants called smear on the near field transducer. In this paper, we investigate the role of optical forces originating from the electric field gradient in the formation of smear. First, based on suitable theoretical approximations, we compare this force with air drag and the thermophoretic force in the head-disk interface for two smear nanoparticle shapes. Then, we evaluate the force field's sensitivity to the relevant parameter space. We find that the smear nanoparticle's refractive index, shape, and volume significantly impact the optical force. Further, our simulations reveal that the interface conditions, such as spacing and the presence of other contaminants, also influence the magnitude of the force. [ABSTRACT FROM AUTHOR]

The activation of water molecules in thermal catalysis typically requires high temperatures, representing an obstacle to catalyst development for the low‐temperature water‐gas shift reaction (WGSR). Plasmonic photocatalysis allows activation of water at low temperatures through the generation of light‐induced hot electrons. Herein, we report a layered double hydroxide‐derived copper catalyst (LD‐Cu) with outstanding performance for the low‐temperature photo‐driven WGSR. LD‐Cu offered a lower activation energy for WGSR to H2 under UV/Vis irradiation (1.4 W cm−2) compared to under dark conditions. Detailed experimental studies revealed that highly dispersed Cu nanoparticles created an abundance of hot electrons during light absorption, which promoted *H2O dissociation and *H combination via a carboxyl pathway, leading to the efficient production of H2. Results demonstrate the benefits of exploiting plasmonic phenomena in the development of photo‐driven low‐temperature WGSR catalysts. [ABSTRACT FROM AUTHOR]

A method for the preparation of polyimide nanofoams with high thermal stability, which can be used as dielectric layers in microelectronics is presented. Poly[styrene-co-(4-vinylpyridine)] (PSVP) nanospheres were prepared by emulsion polymerization. The dimension of these particles is between 30 and 40 nm. PMDA-ODA nanocomposite films with various contents of PSVP were obtained by in-situ condensation polymerization in the presence of the nanospheres, casting of polyamic acid solution containing the nanospheres, and imidization. The dispersion of the nanospheres in the films and the morphology of the composite films were characterized by transmission electron microscopy (TEM) and a gas diffusion method. Relative homogenous distributions were observed for the polyimide/PSVP nanocomposite films, which could be ascribed to the formation of poly(amic acid) amine salts between the pyridinyl groups of the nanosphere and the carboxyl groups of the poly(amic acid) before the films being cured. Upon a thermal treatment, the thermally unstable nanospheres undergo thermolysis, leaving pores the size and shape of which are nearly dictated by the initial nanoparticle morphology. The resultant foams were characterized by TEM, TG, density measurements and dielectric constant measurements respectively. The results showed that foams with high thermal stability and low dielectric constant approaching 2.0 could be prepared using this polyimide nanocomposite approach. [ABSTRACT FROM AUTHOR]

Abstract: Molecular imprinting is an attractive technique for preparing mimics of natural, biological receptors. Nevertheless, the imprinting of macromolecule remains a challenge due to their bulkiness and sensitivity to denaturation. In this work, we presented a method for preparing multifunctional lysozyme-imprinted nanoparticles (magnetic susceptibility, molecular recognition and environmental response). The magnetic susceptibility was imparted through the successful encapsulation of Fe3O4 nanoparticles. Selective lysozyme recognition depended on molecularly imprinted film. Moreover, it was also a hydrophilic stimuli-responsive polymer, which could undergo a reversible change of imprinted cavity in response to a small change in the environmental conditions. Thus, magnetic molecularly imprinted nanoparticles had high adsorption capacity (0.11mgmg−1), controlled selectivity and direct magnetic separation (22.1emug−1) in crude samples. After preconcentration and purification with magnetic MIPs nanoparticles, a sensitive chemiluminescence method was developed for determination of lysozyme in human serum samples. The results indicated that the spiked recoveries were changed from 92.5 to 113.7%, and the RSD was lower than 11.8%. [ABSTRACT FROM AUTHOR]

Abstract: A room temperature method for the encapsulation of pyrene in SiO2 nanoparticles is described. The relation between alkoxysilane surfactant chain length, reactant molar ratios and the uptake of dye, sample morphology, photophysical properties, and the ability of the silicate matrix to protect the encapsulated dye was examined. The synthesis can easily be adapted for the encapsulation of other hydrophobic and thermolabile substances, and used in the development of nanostructured optically active coatings, films and monoliths. [Copyright &y& Elsevier]