Platelet Membrane‐Camouflaged Magnetic Nanoparticles for Ferroptosis‐Enhanced Cancer Immunotherapy

Although cancer immunotherapy has emerged as a tremendously promising cancer therapy method, it remains effective only for several cancers. Photoimmunotherapy (e.g., photodynamic/photothermal therapy) could synergistically enhance the immune response of immunotherapy. However, excessively generated immunogenicity will cause serious inflammatory response syndrome. Herein, biomimetic magnetic nanoparticles, Fe₃O₄‐SAS @ PLT, are reported as a novel approach to sensitize effective ferroptosis and generate mild immunogenicity, enhancing the response rate of non‐inflamed tumors for cancer immunotherapy. Fe₃O₄‐SAS@PLT are built from sulfasalazine (SAS)‐loaded mesoporous magnetic nanoparticles (Fe₃O₄) and platelet (PLT) membrane camouflage and triggered a ferroptotic cell death via inhibiting the glutamate‐cystine antiporter system X_c^? pathway. Fe₃O₄‐SAS @ PLT‐mediated ferroptosis significantly improves the efficacy of programmed cell death 1 immune checkpoint blockade therapy and achieves a continuous tumor elimination in a mouse model of 4T1 metastatic tumors. Proteomics studies reveal that Fe₃O₄‐SAS @ PLT‐mediated ferroptosis could not only induce tumor‐specific immune response but also efficiently repolarize macrophages from immunosuppressive M2 phenotype to antitumor M1 phenotype. Therefore, the concomitant of Fe₃O₄‐SAS @ PLT‐mediated ferroptosis with immunotherapy are expected to provide great potential in the clinical treatment of tumor metastasis.     

Personalized Cancer Immunotherapy via Transporting Endogenous Tumor Antigens to Lymph Nodes Mediated by Nano Fe3O4

While immunotherapy has a tremendous clinical potential to combat cancer, immune responses generated by conventional cancer immunotherapy remain not enough to completely eliminate tumors, mainly due to the tumor's immunosuppressive microenvironment and heterogeneity of tumor immunogenicity. To improve antitumor immune responses and realize personalized immunotherapy, in this report, endogenous tumor antigens (ETAs) that dynamically present on tumor cells are transported to lymph nodes (LNs). Based on the hypothesis that nano Fe₃O₄ (≈10 nm) could serve as the nanocarrier for transporting ETAs from the tumor to LNs, we wondrously find that Fe₃O₄ has a tremendous potential to improve cancer immunotherapy, because of its excellent protein‐captured efficiency and LNs‐targeted ability. To ensure the optimal ETAs‐bound efficiency of Fe₃O₄, a core–shell formulation (denoted as Ce6/Fe₃O₄‐L) is developed and specific release of Fe₃O₄ in tumor is enabled. These findings provide a simple and general strategy for boosting cytotoxic T‐cell response and realizing personalized cancer immunotherapy simultaneously.     

Bioinspired Superhydrophobic Fe3O4@Polydopamine@Ag Hybrid Nanoparticles for Liquid Marble and Oil Spill

Fe₃O₄ nanoparticles (NPs) with Ag NPs evenly distributed on the surface are fabricated by using polydopamine (PDA) as the intermediate layer. Silanization and thiol chemistry are used to firmly combine the Fe₃O₄@ PDA core and outer surface Ag NPs. The spherical and hybrid nanoparticles are termed Fe₃O₄@PDA@Ag NPs, which possess a core–shell and hierarchical structure. After surface modification with 1H,1H,2H,2H‐perfluorodecanethiol, the hybrid Fe₃O₄@PDA@Ag NPs become highly hydrophobic. Slight rolling of a water droplet on the as‐prepared NPs causes the formation of a “liquid marble”, which is capable of performing remote actuation on various solid surfaces, such as glass sheet, paper, plastic, textile, and ceramic, and at the liquid–air interface using a permanent magnet. Liquid marbles with self‐assembled NPs on the liquid surface have potential to act as a miniaturized reactor for manipulation of inner liquid droplet with high positioning precision. In addition, the Fe₃O₄@PDA@Ag NPs are multifunctional and can be applied for oil/water separation and antibacterial purpose.     

Photonic Reactions Leading to Fluorescence in a Polymeric System Induced by the Photothermal Effect of Magnetite Nanoparticles Using a 780 nm Multiphoton Laser

Recently, polymer‐coated magnetite (Fe₃O₄) nanoparticles (NPs) are extensively studied for applications in therapeutics or diagnostics using photothermal effect. Therefore, it is essential to understand the interactions between Fe₃O₄ NPs and polymers when optical stimuli are applied. Herein, the photonic reactions of Fe₃O₄ NPs and polymer composites upon application of a 780 nm multiphoton laser are analyzed. The photonic reactions produce unique results including fluorescence from conformationally changed polymer and low‐temperature phase transformation of Fe₃O₄ NPs. Typically, π‐conjugated chains are formed, inducing fluorescence through a series of main and side‐chain cleavage reactions of polymers with the aliphatic chain. In addition, fluorescence is detected in the cellular system by photonic reactions between Fe₃O₄ NPs and biomolecules. After multiphoton laser irradiation, light emission is detected near the intracellular Fe₃O₄ NPs, and a stronger intensity is observed in large‐sized NPs.     

Red Blood Cell Membrane as a Biomimetic Nanocoating for Prolonged Circulation Time and Reduced Accelerated Blood Clearance

For decades, poly(ethylene glycol) (PEG) has been widely incorporated into nanoparticles for evading immune clearance and improving the systematic circulation time. However, recent studies have reported a phenomenon known as “accelerated blood clearance (ABC)” where a second dose of PEGylated nanomaterials is rapidly cleared when given several days after the first dose. Herein, we demonstrate that natural red blood cell (RBC) membrane is a superior alternative to PEG. Biomimetic RBC membrane‐coated Fe₃O₄ nanoparticles (Fe₃O₄@RBC NPs) rely on CD47, which is a “don't eat me” marker on the RBC surface, to escape immune clearance through interactions with the signal regulatory protein‐alpha (SIRP‐α) receptor. Fe₃O₄@RBC NPs exhibit extended circulation time and show little change between the first and second doses, with no ABC suffered. In addition, the administration of Fe₃O₄@RBC NPs does not elicit immune responses on neither the cellular level (myeloid‐derived suppressor cells (MDSCs)) nor the humoral level (immunoglobulin M and G (IgM and IgG)). Finally, the in vivo toxicity of these cell membrane‐camouflaged nanoparticles is systematically investigated by blood biochemistry, hematology testing, and histology analysis. These findings are significant advancements toward solving the long‐existing clinical challenges of developing biomaterials that are able to resist both immune response and rapid clearance.     

Enhancement of methane production by Methanosarcina barkeri using Fe3O4 nanoparticles as iron sustained release agent

Anaerobic digestion has attracted attention because it does not require power for aeration, it reduces excess sludge and it generates methane gas. However, the growth rate of anaerobic microorganisms is slow, resulting in low treatment efficiency. In this study, the impact of Fe₃O₄ nanoparticles (NPs) on the growth of methanogens, which is the rate-determining step in anaerobic digestion, was investigated using a pure culture of Methanosarcina barkeri as the model methanogen. M. barkeri were cultivated in iron free medium, as well as in media amended with various concentrations of Fe₃O₄ NPs with a mean diameter of 8.1?±?2.4?nm. The production of methane gas was greatly increased when organisms were cultured in media containing NPs. After the methane production was saturated, methanol was newly added to the culture, which resulted in additional methane generation at a higher production rate than occurred during the initial round of cultivation in media containing 20?ppm Fe₃O₄ NPs. In addition, no evidence of negative impacts of Fe₃O₄ NPs on the growth of M. barkeri was observed. Taken together, these results strongly suggest that adding Fe₃O₄ NPs into the fermenter as an agent of sustained iron release can enable sustainable methane fermentation.     

Nanoparticle‐Enhanced Radiotherapy to Trigger Robust Cancer Immunotherapy

External radiotherapy is extensively used in clinic to destruct tumors by locally applied ionizing‐radiation beams. However, the efficacy of radiotherapy is usually limited by tumor hypoxia‐associated radiation resistance. Moreover, as a local treatment technique, radiotherapy can hardly control tumor metastases, the major cause of cancer death. Herein, core–shell nanoparticles based poly(lactic‐co‐glycolic) acid (PLGA) are fabricate, by encapsulating water‐soluble catalase (Cat), an enzyme that can decompose H₂O₂ to generate O₂, inside the inner core, and loading hydrophobic imiquimod (R837), a Toll‐like‐receptor‐7 agonist, within the PLGA shell. The formed PLGA‐R837@Cat nanoparticles can greatly enhance radiotherapy efficacy by relieving the tumor hypoxia and modulating the immune‐suppressive tumor microenvironment. The tumor‐associated antigens generated postradiotherapy‐induced immunogenic cell death in the presence of such R837‐loaded adjuvant nanoparticles will induce strong antitumor immune responses, which together with cytotoxic T‐lymphocyte associated protein 4 (CTLA‐4) checkpoint blockade will be able to effectively inhibit tumor metastases by a strong abscopal effect. Moreover, a long term immunological memory effect to protect mice from tumor rechallenging is observed post such treatment. This work thus presents a unique nanomedicine approach as a next‐generation radiotherapy strategy to enable synergistic whole‐body therapeutic responses after local treatment, greatly promising for clinical translation.     

MWCNTs as Conductive Network for Monodispersed Fe3O4 Nanoparticles to Enhance the Wave Absorption Performances

Magnetic oxides are widely used as electromagnetic (EM) wave absorbers. To promote the absorption efficiency, tremendous efforts have been contributed to adjusting the composite, structure, and size of magnetic loss materials. Employing carbon materials (CNTs, CF, graphene, PANI) is an efficient way to improve the dielectric loss of the matrix. Anchoring the tiny‐monodispersed Fe₃O₄ nanoparticles (NPs) onto the lightweight multi ? walled carbon nanotubes (MWCNTs) leads to improve dielectric loss and impedance matching characteristic. Magnetic Fe₃O₄ NPs along the one‐dimensional nanotubes direction play a good synergetic role with MWCNTs due to the interfacial strong chemical and structure bonding. The as‐synthesized Fe₃O₄/MWCNTs nanocomposites exhibit efficient EM wave absorption characteristics (R_L av?10 dB) with a maximum reflection loss of ?63.64 dB at 12.08 GHz and a diminutive thickness of only 1.6 mm. The magnetic Fe₃O₄ NPs show strong chemical and structure bonding with the one‐dimensional MWCNTs. This work may show a way to broaden the application of such kinds of lightweight high‐performance absorbing materials frameworks.

     

Molecular Engineering of NIR-II/IIb Emitting AIEgen for Multimodal Imaging-Guided Photo-Immunotherapy

In view of the great challenges related to the complexity and heterogeneity of tumors, efficient combination therapy is an ideal strategy for eliminating primary tumors and inhibiting distant tumors. A novel aggregation-induced emission (AIE) phototherapeutic agent called T-TBBTD is developed, which features a donor–acceptor–donor (D–A–D) structure, enhanced twisted molecule conformation, and prolonged second near-infrared window (NIR-II) emission. The multimodal imaging function of the molecule has significance for its treatment time window and excellent photothermal/photodynamic performance for multimode therapy. The precise molecular structure and versatility provide prospects for molecular therapy for anti-tumor applications. Fluorescence imaging in the NIR-II window offers advantages with enhanced spatial resolution, temporal resolution, and penetration depth. The prepared AIE@R837 NPs also have controllable performance for antitumor photo-immunotherapy. Following local photo-irradiation, AIE@R837 NPs generate abundant heat, and ¹O₂ directly kills tumor cells, induces immunogenic cell death (ICD) as a photo-therapeutic effect, and releases R837, which enhances the synergistic effect of antigen presentation and contributes to the long-lasting protective antitumor immunity. A bilateral 4T1 tumor model revealed that this photo-immunotherapy can eliminate primary tumors. More importantly, it has a significant inhibitory effect on distant tumor growth. Therefore, this method can provide a new strategy for tumor therapy.     

Cement-based composites endowed with novel functions through controlling interface microstructure from Fe3O4@SiO2 nanoparticles

In this paper, Fe₃O₄@SiO₂ nanoparticles (NPs) were introduced in the surface layer of cement-based materials derived by magnetic field to create a wave adsorbing layer. The cement-based materials treated with Fe₃O₄@SiO₂ NPs revealed superior microwave-absorption property comparing with the samples treated with pure Fe₃O₄ NPs. Because of a SiO₂ coating on Fe₃O₄ NPs, water absorption rates of cement mortars treated with Fe₃O₄@SiO₂ NPs have reduced by 45.3%. In addition, the SiO₂ coating on Fe₃O₄ NPs bonded wave absorbing materials on the surface of cement-based composites by forming a mass of SiO₂ and calcium silicate hydrate (C-S-H) gels. The Fe₃O₄@SiO₂ NPs can be considered as an ideal wave absorption surface-treatment agent for cement-based composites.     

Dendrimer‐Assisted Formation of Fe3O4/Au Nanocomposite Particles for Targeted Dual Mode CT/MR Imaging of Tumors

A unique dendrimer‐assisted approach is reported to create Fe₃O₄/Au nanocomposite particles (NCPs) for targeted dual mode computed tomography/magnetic resonance (CT/MR) imaging of tumors. In this approach, preformed Fe₃O₄ nanoparticles (NPs) are assembled with multilayers of poly(γ‐glutamic acid) (PGA)/poly(l ‐lysine)/PGA/folic acid (FA)‐modified dendrimer‐entrapped gold nanoparticles via a layer‐by‐layer self‐assembly technique. The interlayers are crosslinked via 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide chemistry, the assembled Au core NPs are then used as seed particles for subsequent seed‐mediated growth of Au shells via iterative Au salt reduction process, and subsequent acetylation of the remaining amines of dendrimers leads to the formation of Fe₃O₄/Au_n.Ac‐FA NCPs with a tunable molar ratio of Au/Fe₃O₄. It is shown that the Fe₃O₄/Au_n.Ac‐FA NCPs at an optimized Au/Fe₃O₄ molar ratio of 2.02 display a relatively high R₂ relaxivity (92.67 × 10^?3 M^?1 s^?1) and good X‐ray attenuation property, and are cytocompatible and hemocompatible in the given concentration range. Importantly, with the FA‐mediated targeting, the Fe₃O₄/Au_n.Ac‐FA NCPs are able to be specifically uptaken by cancer cells overexpressing FA receptors, and be used as an efficient nanoprobe for targeted dual mode CT/MR imaging of a xenografted tumor model. With the versatile dendrimer chemistry, the developed Fe₃O₄/Au NCPs may be differently functionalized, thereby providing a unique platform for diagnosis and therapy of different biological systems.     

Study of Structural and Magnetic Properties of Superparamagnetic Fe3O4–ZnO Core–Shell Nanoparticles

In this work, Fe₃O₄–ZnO core–shell nanoparticles have been successfully synthesized using a simple two-step co-precipitation method. In this regard, Fe₃O₄ (magnetite) and ZnO (zincite) nanoparticles (NPs) were synthesized separately. Then, the surface of the Fe₃O₄ NPs was modified with trisodium citrate in order to improve the attachment of ZnO NPs to the surface of Fe₃O₄ NPs. Afterwards, the modified magnetite NPs were coated with ZnO NPs. Moreover, the influence of the core to shell molar ratio on the structural and magnetic properties of the core–shell NPs has been investigated. The prepared nanoparticles have been characterized utilizing transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometer (VSM). The results of XRD indicate that Fe₃O₄ NPs with inverse spinel phase were formed. The results of VSM imply that the Fe₃O₄–ZnO core–shell NPs are superparamagnetic. The saturation magnetization of prepared Fe₃O₄ NPs is 54.24 emu/g and it decreases intensively down to 29.88, 10.51 and 5.75 emu/g, after ZnO coating with various ratios of core to shell as 1:1, 1:10 and 1:20, respectively. This reduction is attributed to core–shell interface effects and shielding. TEM images and XRD results imply that ZnO-coated magnetite NPs are formed. According to the TEM images, the estimated average size for most of core–shell NPs is about 12 nm.     

Electrospun magnetic poly(l-lactide) (PLLA) nanofibers by incorporating PLLA-stabilized Fe3O4 nanoparticles

Magnetic poly(l-lactide) (PLLA)/Fe₃O₄ composite nanofibers were prepared with the purpose to develop a substrate for bone regeneration. To increase the dispersibility of Fe₃O₄ nanoparticles (NPs) in the PLLA matrix, a modified chemical co-precipitation method was applied to synthesize Fe₃O₄ NPs in the presence of PLLA. Trifluoroethanol (TFE) was used as the co-solvent for all the reagents, including Fe(II) and Fe(III) salts, sodium hydroxide, and PLLA. The co-precipitated Fe₃O₄ NPs were surface-coated with PLLA and demonstrated good dispersibility in a PLLA/TFE solution. The composite nanofiber electrospun from the solution displayed a homogeneous distribution of Fe₃O₄ NPs along the fibers using various contents of Fe₃O₄ NPs. X-ray diffractometer (XRD) and vibration sample magnetization (VSM) analysis confirmed that the co-precipitation process had minor adverse effects on the crystal structure and saturation magnetization (Ms) of Fe₃O₄ NPs. The resulting PLLA/Fe₃O₄ composite nanofibers showed paramagnetic properties with Ms directly related to the Fe₃O₄ NP concentration. The cytotoxicity of the magnetic composite nanofibers was determined using in vitro culture of osteoblasts (MC3T3-E1) in extracts and co-culture on nanofibrous matrixes. The PLLA/Fe₃O₄ composite nanofibers did not show significant cytotoxicity in comparison with pure PLLA nanofibers. On the contrary, they demonstrated enhanced effects on cell attachment and proliferation with Fe₃O₄ NP incorporation. The results suggested that this modified chemical co-precipitation method might be a universal way to produce magnetic biodegradable polyester substrates containing well-dispersed Fe₃O₄ NPs. This new strategy opens an opportunity to fabricate various kinds of magnetic polymeric substrates for bone tissue regeneration.     

Heterogeneous Fenton-like discoloration of methyl orange using Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/MWCNTs as catalyst: combination mechanism and affecting parameters

Multi-walled carbon nanotubes (MWCNTs) can act not only as a support for Fe₃O₄ nanoparticles (NPs) but also as a coworker with synergistic effect, accordingly improving the heterogeneous Fenton-like efficiency of Fe₃O₄ NPs. In this study, Fe₃O₄ NPs were in situ anchored onto MWCNTs by a moderate co-precipitation method and the as-prepared Fe₃O₄/MWCNTs nanocomposites were employed as the highly efficient Fenton-like catalysts. The analyses of XRD, FTIR, Raman, FESEM, TEM and HRTEM results indicated the formation of Fe₃O₄ crystals in Fe₃O₄/MWCNTs nanocomposites prepared at different conditions and the interaction between Fe₃O₄ NPs and MWCNTs. Over a wide pH range, the surface of modified MWCNTs possessed negative charges. Based on these results, the possible combination mechanism between Fe₃O₄ NPs and MWCNTs was discussed and proposed. Moreover, the effects of preparation and catalytic conditions on the Fenton-like catalytic efficiency were investigated in order to gain further insight into the heterogeneous Fenton-like reaction catalyzed by Fe₃O₄/MWCNTs nanocomposites.     

Effect of magnetite nanoparticles on dye absorption properties of magnetite@carbon composites

Magnetite@carbon (Fe₃O₄@C) composites were prepared using three kinds of Fe₃O₄ nanoparticles (NPs). All the Fe₃O₄@C composites could be easily separated from water by an external magnet. The Fe₃O₄ NPs synthesized by a microreactor system have the smallest size and narrowest size distribution among the three kinds of Fe₃O₄ NPs. The saturated capacity of the Fe₃O₄@C composite originating from microreactor-prepared Fe₃O₄ NPs to absorb Rhodamine B at 2 0 ^° C exceeds 135 mg g ^{? 1} , which is 1.35 times as much as the value of the Fe₃O₄@C composite originating from traditional Fe₃O₄ NPs. This value for the Fe₃O₄@C composite using commercial Fe₃O₄ NPs as core is only 76 mg g ^{? 1} . The Fe₃O₄@C composite using microreactor-prepared Fe₃O₄ NPs also has good retrievability and reusability.     

Fast microwave synthesis of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> and Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/Ag magnetic nanoparticles using Fe<Superscript>2+</Superscript> as precursor

A simple and quick microwave method to prepare high performance magnetite nanoparticles (Fe₃O₄ NPs) directly from Fe has been developed. The as-prepared Fe₃O₄ NPs product was fully characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The results show that the as-prepared Fe₃O₄ NPs are quite monodisperse with an average core size of 80 × 5 nm. The microwave synthesis technique can be easily modified to prepare Fe₃O₄/Ag NPs and these NPs possess good magnetic properties. The formation mechanisms of the NPs are also discussed. Our proposed synthesis procedure is quick and simple, and shows potential for large-scale production and applications for catalysis and biomedical/biological uses.     

Polyphenol‐Inspired Facile Construction of Smart Assemblies for ATP‐ and pH‐Responsive Tumor MR/Optical Imaging and Photothermal Therapy

Smart assemblies have attracted increased interest in various areas, especially in developing novel stimuli‐responsive theranostics. Herein, commercially available, natural tannic acid (TA) and iron oxide nanoparticles (Fe₃O₄ NPs) are utilized as models to construct smart magnetic assemblies based on polyphenol‐inspired NPs–phenolic self‐assembly between NPs and TA. Interestingly, the magnetic assemblies can be specially disassembled by adenosine triphosphate, which shows a stronger affinity to Fe₃O₄ NPs than that of TA and partly replaces the surface coordinated TA. The disassembly can further be facilitated by the acidic environment hence causing the remarkable change of the transverse relaxivity and potent “turn‐on” of fluorescence (FL) signals. Therefore, the assemblies for specific and sensitive tumor magnetic resonance and FL dual‐modal imaging and photothermal therapy after intravenous injection of the assemblies are successfully employed. This work not only provides understandings on the self‐assembly between NPs and polyphenols, but also will open new insights for facilely constructing versatile assemblies and extending their biomedical applications.     

Structural design and synthesis of new MOO3-x interlayer bi-functional nanomaterials for enhanced up-conversion luminescence properties

A novel imaging materials based on bi-functional Fe₃O₄@M_OO_3-x@YF₃:Yb/Er nanoparticles (NPs) with strong up-conversion luminescence and magnetic properties was designed and synthesized by inlaying M_OO_3-x with localized surface plasmon resonance (LSPR) and ferromagnetic property in the bi-functional Fe₃O₄@YF₃:Yb/Er NPs. The morphology, structure and properties of Fe₃O₄@M_OO_3-x@YF₃:Yb/Er NPs are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), photoluminescence (PL) spectra, UV–Vis-NIR spectrophotometer and superconducting quantum interference devices (SQUID). It was found that the experimental conditions (reaction temperature, reaction time, the mass ratio of core:shell and oxygen pressure in heat treatment) have a certain effect on the oxygen defect concentration of the M_OO_3-x interlayer. XRD also showed the crystal structure of Fe₃O₄, Fe₃O₄@M_OO_3-x and Fe₃O₄@M_OO_3-x@YF₃:Yb/Er NPs. The SEM and TEM results showed that the average grain size of the prepared NPs were 200 nm. The SQUID and PL results showed that the Fe₃O₄@M_OO_3-x@YF₃:Yb/Er NPs have stronger magnetism (14.3 emu/g) and excellent up-conversion luminescence performance (the emission peak at 525 nm is nearly 20 times higher than the corresponding emission intensity of the Fe₃O₄@YF₃:Yb/Er). The Fe₃O₄@M_OO_3-x@YF₃:Yb/Er NPs can be easily used to magnetic resonance and fluorescence dual-mode image-guided visual delivery drug and also increase the accurate diagnosis and treatment effect of malignant tumor.     

Glycocalyx‐Mimicking Nanoparticles for Stimulation and Polarization of Macrophages via Specific Interactions

Malignant tumors develop multiple mechanisms to impair and escape from antitumor immune responses, of which tumor‐associated macrophages that often show immunosuppressive phenotype (M2), play a critical role in tumor‐induced immunosuppression. Therefore, strategies that can reverse M2 phenotype and even enhance immune‐stimulation function of macrophage would benefit tumor immunotherapy. In this paper, self‐assembled glyco‐nanoparticles (glyco‐NPs), as artificial glycocalyx, have been found to be able to successfully induce the polarization of mouse primary peritoneal macrophages from M2 to inflammatory type (M1). The polarization change was evidenced by the decreased expression of cell surface signaling molecules CD206 and CD23, and the increased expression of CD86. Meanwhile, secretion of cytokines supported this polarization change as well. More importantly, this phenomenon is observed not only in vitro, but also in vivo. As far as we known, this is the first report about macrophage polarization being induced by synthetic nanomaterials. Moreover, preparation, characterization of these glyco‐NPs and their interaction with the macrophages are also demonstrated.     

Green synthesis and characterisation of L-Serine capped magnetite nanoparticles for removal of Rhodamine B from contaminated water

ABSTRACT

This paper describes a green one-pot synthesis of L-Serine (L-Ser) capped magnetite nanoparticles (Fe₃O₄ NPs) and its potential application for adsorption of RhB dye from aqueous solution. The surface property, structure, morphology and magnetic properties of as prepared L-Ser capped Fe₃O₄ NPs were characterised through UV-Visible spectroscopy, Fourier transform-infrared spectroscopy, X-Ray Diffraction (XRD), scanning electron microscope, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD results were indicated the formation of high crystalline spinel type Fe₃O₄ NPs. TEM images were shown the spherical shape of L-Ser capped Fe₃O₄ NPs with particle size of 5.9 nm. The VSM curve showed the superparamagnetic behaviour of L-Ser capped Fe₃O₄. A plausible interaction mechanism of L-Ser and Fe₃O₄ NPs was also investigated. L-Ser capped Fe₃O₄ NPs due to its large surface area and a strong magnetism was shown potential adsorption efficiency towards RhB dye from aqueous solution. The adsorption isotherm data fitted well with Langmuir isotherm model and the monolayer adsorption capacity (q_e,exp) was found to be 6.82 mg/g at pH 7.4 and 300 K. The experimental kinetic data fitted very well with the pseudo-second-order model. The thermodynamic studies reveal that adsorption efficiency is critically dependent on temperature.