Low Biological Toxicity Research Articles

A novel iron oxide (Fe3O4)-laden titanium carbide (Ti3C2) MXene stacks for the efficient removal of tetracycline from aqueous solution

Fe3O4 has the advantages of unique magnetic stability and low biological toxicity, which can improve pollutants separation efficiency. MXenes are two-dimensional materials and easy surface functionalization that can provide suitable carriers for Fe3O4. In this work, we synthesized magnetic MXene composites by a one-pot method that relies on doping Fe3O4 particles onto Ti3C2 MXene nanosheets by heat treatment. The Fe3O4/Ti3C2 MXene was analyzed by SEM, XRD, FTIR and XPS techniques, which showed that the material has good tetracycline (TC) removal properties and magnetic separation ability. The results showed that the adsorption capacity of it was 46.42 mg g−1, and the removal efficiency of 0.06 g adsorbent for 50 mL of 30 mg L−1 TC could reach 92.1% in a wide pH range of 4–10, when the adsorption temperature was 25 °C, and the adsorption time was 3 h. The adsorption data were consistent with Langmuir and the proposed second-order kinetic model, and the thermodynamic experiments confirmed that the adsorption of TC was a monolayer physicochemical adsorption coexisting heat-trapping process (ΔH = 15.72 kJ mol−1). In addition, the adsorption of TC by Fe3O4/Ti3C2 MXene was attributed to the synergistic effect of electrostatic attraction, hydrogen bonding and π-π packing. In conclusion, the saturation magnetization of Fe3O4/Ti3C2 MXene is 27.3 emu/g and it can not only be separated from water using its strong magnetic properties to avoid secondary contamination, but also can be used as a promising material to effectively remove antibiotics from aqueous media.

Establishment of a Rapid Detection Method for Cadmium Ions via a Specific Cadmium Chelator N-(2-Acetamido)-Iminodiacetic Acid Screened by a Novel Biological Method.

Heavy metal ions such as cadmium, mercury, lead, and arsenic in the soil cannot be degraded naturally and are absorbed by crops, leading to accumulation in agricultural products, which poses a serious threat to human health. Therefore, establishing a rapid and efficient method for detecting heavy metal ions in agricultural products is of great significance to ensuring the health and safety. In this study, a novel optimized spectrometric method was developed for the rapid and specific colorimetric detection of cadmium ions based on N-(2-Acetamido)-iminodiacetic acid (ADA) and Victoria blue B (VBB) as the chromogenic unit. The safety evaluation of ADA showed extremely low biological toxicity in cultured cells and live animals. The standard curve is y = 0.0212x + 0.1723, R2 = 0.9978, and LOD = 0.08 μM (0.018 mg/kg). The liner concentrations detection range of cadmium is 0.1-10 μM. An inexpensive paper strip detection method was developed with a detection limit of 0.2 μM to the naked eye and a detection time of less than 1 min. The method was successfully used to assess the cadmium content of rice, soybean, milk, grape, peach, and cabbage, and the results correlated well with those determined by inductively coupled plasma-mass spectrometry (ICP-MS). Thus, our study demonstrated a novel rapid, safe, and economical method for onsite, real-time detection of cadmium ions in agricultural products.

Sustainable water sterilization by nano-ZnO using anisotropic polysaccharide columns derived from agro-waste stalk

The escalating demand for clean water and proliferation of microbial contamination in water have challenged ecosystems and human health safety. ZnO NPs are widely used as environmental restoration agents, but their efficacy in water decontamination is hindered by low biological toxicity. In order to enhance its sterilization efficiency, we propose a top-down strategy utilizing the unique maze structure of corn stalk pith (CSP) as a germ trapper for ZnO. The in-situ delignified CSP offers abundant active sites for the adsorption of Zn2+, exhibiting the typical behaviors of monolayer, physisorption, endothermicity, spontaneity, and randomness. This adsorption behavior exerts an influence on microscopic morphology of the composite column, consequently resulting in alterations to antibacterial properties. The results show that the hybrid column fabricated under the Zn2+ initial dosage of 1.00 mol/L at 30 h for 40 °C, possesses such optimal features as stacked grain-shaped ZnO NPs of 669.3 mg/g loading amount with adhesion coefficients of 0.73 ∼ 0.86 for bacterial microparticles. Consequently, the assembled bio-filter can eliminate E. coli and S. aureus as high as 99.7 % and 96.5 % respectively, attributed to CSPP labyrinth structure to enhance pathogen capture from water and facilitate ZnO-mediated inactivation. The collective findings emphasize the viability of agro-waste stalks as bio-filters for water purification.

Development of a Supermolecular Radionuclide-Drug Conjugate System for Integrated Radiotheranostics for Non-small Cell Lung Cancer.

Radionuclide-drug conjugates (RDCs) designed from small molecule or nanoplatform shows complementary characteristics. We constructed a new RDC system with integrated merits of small molecule and nanoplatform-based RDCs. Erlotinib was labeled with 131I to construct the bulk of RDC (131I-ER). Floxuridine was mixed with 131I-ER to develop a hydrogen bond-driving supermolecular RDC system (131I-ER-Fu NPs). The carrier-free 131I-ER-Fu NPs supermolecule not only demonstrated integrated merits of small molecule and nanoplatform-based RDC, including clear structure definition, stable quality control, prolonged circulation lifetime, enhanced tumor specificity and retention, and rapidly nontarget clearance, but also exhibited low biological toxicity and stronger antitumor effects. In vivo imaging also revealed its application for tumor localization of nonsmall cell lung cancer (NSCLC) and screening of patients suitable for epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. We considered that 131I-ER-Fu NPs showed potentials as an integrated platform for the radiotheranostics of NSCLC.

Design and application of Cd2+ polypeptide fluorescent probes based on Aggregation Induced Emission (AIE).

Cadmium is a toxic heavy metal, which is both an environmental pollutant, and a threat to human health. A fluorescent probe was developed to detect Cd2+ selectively, sensitively, and quickly. This study reports the successful development of a polypeptide fluorescent probe TPE-HC (TPE-His-Pro-Gly-Cys) which selectively detects Cd2+ by Aggregation-Induced Emission effect. After fluorescence excitation, Cd2+ can be effectively detected based on the change of fluorescence intensity. The detection limit of Cd2+ in buffer solution was determined to be 151 nM (R2 = 0.9933). This probe exhibits high sensitivity, high cell permeabilit y, and low biological toxicity, and can perform live cell imaging under biological conditions. This study indicates that TPE-HC can detect Cd2+ in biological environments.

Multifunctional antibacterial enhanced amoxicillin carbon nanodots for the detection of Hg (II) and methanol in edible alcohol

Amoxicillin was used as the sole precursor to rapidly synthesize amoxicillin carbon nanodots via a one-step microwave method. The diameter of the amoxicillin carbon nanodots was concentrated at 1.8 ± 0.6 nm, with fluorescence excitation-dependent characteristics. After characterization, the carbon nanodots retained some of the amoxicillin structure, exhibiting low biological toxicity and good antibacterial activity. Due to the formation of the carbon dots structure, the hydrophilicity and water solubility of the amoxicillin carbon nanodots improved. An antibacterial plate experiment further showed that the antibacterial performance of the amoxicillin carbon nanodots was higher than that of the original amoxicillin. The amoxicillin carbon nanodots could quickly and conveniently detect Hg2+ via changes in their fluorescence intensity. Moreover, several aliphatic alcohols could be distinguished and quantified based on the fluorescence intensity increase of the amoxicillin carbon nanodots. Most importantly, the amoxicillin carbon nanodots quickly identified and quantified methanol mixed in edible alcohol. These multifunctional amoxicillin carbon nanodots have broad application prospects in antibiosis, toxic Hg2+ detection, and identification and detection of several aliphatic alcohols, especially the microfluorometric determination of methanol in edible alcoholic beverages.

Fibroblast activation protein-sensitive polymeric nanobeacon for early diagnosis of renal fibrosis

Early diagnosis and treatment of renal fibrosis (RF) significantly affect the clinical outcomes of chronic kidney diseases (CKDs). As the typical fibrotic ailment, RF is characterized by remodeling of the extracellular matrix, and the activation of fibroblast activation protein (FAP) plays a crucial role in the mediation of extracellular matrix protein degradation. Therefore, FAP can serve as a biomarker for RF. However, up to now, no effective tools have been reported to diagnose early-stage RF via detecting FAP. In this work, a polymeric nanobeacon integrating an FAP-sensitive amphiphilic polymer and fluorophores was proposed, which was used to diagnose early RF by sensing FAP. The FAP can be detected in the range of 0 to 200 ng/mL with a detection limit of 0.132 ng/mL. Furthermore, the fluorescence imaging results demonstrate that the polymeric nanobeacon can sensitively image fibrotic kidneys in mice with unilateral ureteral occlusion (UUO), suggesting its potential for early RF diagnosis and guidance of FAP-targeted treatments. Importantly, when employed alongside with non-invasive diagnostic techniques like magnetic resonance imaging (MRI) and serological tests, this nanobeacon exhibits excellent biocompatibility, low biological toxicity, and sustained imaging capabilities, making it a suitable fluorescent tool for diagnosing various FAP-related fibrotic conditions. To our knowledge, this study represents the first attempt to image RF in early stage by detecting FAP, offering a promising fluorescent molecular tool for diagnosing various FAP-associated diseases in the future.

Harnessing the power of polyethyleneimine in modifying chitosan surfaces for efficient anion dyes and hexavalent chromium removal

In this investigation, synthesis of a surface-functionalized chitosan known as amino-rich chitosan (ARCH) was achieved by successful modification of chitosan by polyethyleneimine (PEI). The synthesized ARCH was characterized by a specific surface area of 8.35 m2 g−1 and a microporous structure, with pore sizes predominantly under 25 nm. The Zeta potential of ARCH maintained a strong positive charge across a wide pH range of 3–11. These characteristics contribute to its high adsorption efficiency in aqueous solutions, demonstrated by its application in removing various anionic dyes, including erioglaucine disodium salt (EDS), methyl orange (MO), amaranth (ART), tartrazine (TTZ), and hexavalent chromium ions (Cr(VI)). The adsorption capacities (Qe) for these contaminants were measured at 1301.15 mg g−1 for EDS, 1025.45 mg g−1 for MO, 940.72 mg g−1 for ART, 732.96 mg g−1 for TTZ, and 350.15 mg g−1 for Cr(VI). A significant observation was the rapid attainment of adsorption equilibrium, occurring within 10 min for ARCH. The adsorption behavior was well-described by the Pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption process is spontaneous and endothermic in nature. Additionally, an increase in temperature was found to enhance the adsorption capacity of ARCH. The material demonstrated robust stability and selective adsorption capabilities in varied conditions, including different organic compounds, pH environments, sodium salt presence, and in the face of interfering ions. After five cycles of adsorption, ARCH maintained about 60% of its initial adsorption capacity. Due to its efficient adsorption performance, simple synthesis process, low biological toxicity, and cost-effectiveness, ARCH is a promising candidate for future water treatment technologies.

A Review of Advances in Graphene Quantum Dots: From Preparation and Modification Methods to Application

Graphene quantum dot (GQD) is a new type of carbon nanometer material. In addition to the excellent properties of graphene, it is superior due to the quantum limit effect and edge effect. Because of its advantages such as water solution, strong fluorescent, small size, and low biological toxicity, it has important application potential in various fields, especially in sensors and biomedical areas, which are mainly used as optical electrical sensors as well as in biological imaging and tumor therapy. In addition, GQDs have very important characteristics, such as optical and electrical properties. There are many preparation methods, divided into top-down and bottom-up methods, which have different advantages and disadvantages, respectively. In addition, the modification methods include heterogeneous doping, surface heterogeneity, etc. There are still many challenges in developing GQDs. For example, the synthesis steps are still hard to conduct, but as the inquiry continues to deepen, GQDs will be revolutionary materials in the future. In this work, the literature concerning research progress on GQDs has been reviewed and summarized, while the key challenges of their application have been pointed out, which may bring new insights to the application of GQDs.

PH-responsive iron-loaded carbonaceous nanoparticles for chemodynamic therapy based on the Fenton reaction.

The Fenton reaction-based chemodynamic therapy is a form of cancer therapy, and its efficacy can be significantly improved by promoting catalytic reactions involving iron ions. A system with high catalytic capacity and low biological toxicity that effectively inhibits tumor progression is required for optimal treatment. In this study, iron-loaded carbonaceous nanoparticles (CNPs@Fe) with Fenton catalytic activity were fabricated and applied for the chemodynamic therapy of cancer. The carbonaceous nanoparticles derived from glucose via a caramelization reaction demonstrated high biocompatibility. Besides, aromatic structures in the carbonaceous nanoparticles helped accelerate electron transfer to enhance the catalytic decomposition of H2O2, resulting in the formation of highly reactive hydroxyl radicals (˙OH). At pH 6.0 (representing weak acidity in the tumor microenvironment), the Fenton catalytic activity of CNPs@Fe in the decomposition of H2O2 was 15.3 times higher than that of Fe2+ and 28.3 times higher than that of Fe3O4via a chromogenic reaction. The reasons for the enhancement were revealed by analyzing the chemical composition of carbonaceous nanoparticles using high-resolution mass spectra. The developed Fenton agent also demonstrated significant therapeutic effectiveness and minimal side effects in in vitro and in vivo anticancer studies. This work proposes a novel approach to promote the generation of reactive oxygen species (ROS) for the chemodynamic therapy of cancer.

Precise optical engineering of carbon-based photoluminescence arrays based on e-beam irradiation process

Photoluminescent carbonnanomaterials have been widely studied for their low biological toxicity, outstanding biocompatibility, unique physical–chemical properties and obvious PL properties. The reliable fabrication of high-resolution fluorescence arrays has important significance in further studies and applications. The organic resist can be in-situ transferred into specific carbon-based micro-nano structure with fluorescence properties under e-beam irradiation. In this work, polymethyl methacrylate (PMMA) thin film was adopted for preparing solid-carbon nanostructures with 23.89 nm feature size. In a dark field environment, the structure has presented broad luminescent spectrum with maximum at 600 nm. Considering the significant influence of the surface molecular state on solid-carbon arrays, ammonia solution was used to enhance the PL intensity of the sample. The results verified that PL intensity was enhanced by a factor of 17 before and after ammonia solution treatment. Then carbon-based nanostructures were also fabricated on the surface of MoS2 film for studying PL properties between 2D materials and carbon-based dot arrays. The results show that superposition state was produced based on PL intensity and peak location of the solid-carbon dot array and MoS2 film. The optical behavior study of high-resolution solid-carbon arrays will provide a powerful supplement for carbon-based photophysical study and high-performance sensing devices.

Cellulose circular economy: Amino-functionalized graphene quantum dots as highly sensitive vaccine indicators

Cellulose is a highly content natural polymer that can be extracted from plants. Rice straw is a valuable resource because it is rich in cellulose. This study aims to develop a technology to extract and utilize cellulose from rice straw, which would otherwise be discarded. Cellulose derived from rice straw is used to synthesize low-biotoxicity, high-performance graphene quantum dots. Cellulose is hydrolyzed into glucose and processed into graphene quantum dots using the hydrothermal method, which is a green synthetic route. The 3-(4,5-dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide assay shows that the natural biomass (cellulose)-derived graphene quantum dots have low biological toxicity and cell viability that exceeds 100% (48 h, 400 micrograms per milliliter). Their luminescence properties, chemical stability, and biological toxicity are significantly improved by subsequent reduction and amination. Subsequently, amino-functionalized graphene quantum dots are used as a display agent for vaccine detection, which quantified secondary antibody concentration with a detection limit of 2 pg/mL, excellent linearity (r2 = 0.9982), and a low coefficient of variation of < 0.04%, outperforming the existing 3,3′5,5′-tetramethylbenzidine. This study demonstrates that graphene quantum dots synthesized from natural polymers are suitable for low-toxicity applications, such as vaccine indicators.

Analysis of the process of resource utilization of AMPS kettle residues

As a widely used synthetic raw material in industrial production, a large amount of 2-Acrylamido-2-methylpropanesulfonic acid (AMPS) is produced every year. However, many wastes will be generated from the kettle residues of AMPS production. If these wastes are not properly disposed of in a timely manner, they can result in environmental pollution, pose environmental hazards, and lead to economic losses. In this paper, a new process technology is proposed in which the waste from the AMPS reactor residue can be combined with acrylic acid (AA) to create a new polymer.This polymer has a structure similar to the industrial scale inhibitor TH3100 as shown by the NMR, FTIR and TG analysis. Scale inhibition experiments are conducted on CaCO3, Ca3(PO4)2 and CaSO4 to demonstrate the polymer's excellent scale inhibition performance. Besides, the polymer shows a low biological toxicity as proved by zebrafish toxicity tests. Thus, the proposed novel process technology not only manages the waste in the AMPS kettle, but also resources it as an alternative to industrial-scale inhibitors, producing economic benefits as well as protecting the environment.

Polyphenol‐mediated construction of highly stable and bioactive selenium nanoparticles

AbstractSelenium (Se), a well‐known essential element in human health, plays a vital role in regulating metabolism owing to its antioxidative nature. However, organic Se compounds are toxic and cannot be used for biomedical applications. Selenium nanoparticles (SeNPs) exhibit low biological toxicity and high bioavailability; however, they are prone to aggregation and are extremely unstable, thereby diminishing their bioactivity and bioavailability. To overcome these limitations, ultra‐small, highly stable, and bioactive SeNPs were synthesised based on an in‐situ hybridisation strategy by using polyphenol‐grafted‐chitosan (GA‐CS) to control and restrict crystal growth of Se nanoparticles. The resultant GA‐CS@nSe exhibited an average particle size of ∼30 nm and was highly stable in aqueous solutions. In addition, GA‐CS@nSe displayed improved biocompatibility and enhanced antioxidative activity. Taken together, the authors provide a basis for polyphenol‐mediated construction of Se‐based particles with increased bioactivity.

Synergistic enhancement of chemotherapy for bladder cancer by photothermal dual-sensitive nanosystem with gold nanoparticles and PNIPAM

Bladder cancer is a common malignant tumor of the urinary system with the potential to be treated by nano drug delivery system. The current work describes the synthesis and characterization of a novel nanomaterial to construct a nano-carrier based on 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphatecholine (POPC) loaded doxorubicin (DOX) and embedded with gold nanoparticles and poly(N-isopropyl acrylamide) (PNIPAM) (GNPS@PNIPAM-POPC-DOX, GPPD). The dual-sensitive nanosystem gives simultaneous photothermal treatment and chemotherapy for bladder cancer. In vitro and in vivo properties were assessed using bladder cancer cell lines and mice and GPPD system distribution, tumor inhibition, and biocompatibility are reported. The system had favorable stability, low biological toxicity, controlled release efficiency, photothermal synergistic action, efficient photothermal transition, and favorable tumor suppressive effects. As a result, GPPD is a potential therapeutic approach for bladder cancer.

(Invited) Tuning Optoelectronic and Chiroptical Properties of Carbon Dots Based Hybrids

Carbon dots (CDs) are a rising star in carbon nanomaterials due to their easy preparation and numerous potential applications. With a diameter from a few to tens of nanometers, and a tunable structure, composition, and morphology, they integrate the merits of water solubility, low biological toxicity, and diversity of opto-electronic properties. Commonly, they are categorized into different subgroups, where graphene quantum dots (GQDs) and carbon nanodots (CNDs) can be found. GQDs are two-dimensional nanoparticles of one or few-layer graphene sheets formed during the exfoliation processes of graphitic materials, whereas CNDs are amorphous nanoparticles fabricated from easily affordable organic precursors, natural products, or waste.In recent years, we have set-up methodologies for the synthesis of GQDs and CNDs, carried out a detailed characterization of the obtained structures, and explored the modulation of properties by chemical modification of these carbon nanostructures, as part of the objectives of our research.Special attention was dedicated to customize the optoelectronic properties of GQDs and CNDs, and to investigate the electronic communication in related functional materials.1 Both, electron-donor and electron-acceptor character of GQDs and CNDs, make their charge-transfer chemistry rather versatile. Charge-separated states are observed in the photoexcitation of CNDs previously endowed with electron-donating extended tetrathiafulvalenes (exTTF) or electron-accepting 11,11,12,12-tetracyano-9,10-anthra-p-quinodimethanes (TCAQ).In a different approach, the top-down synthesis of chiral GQDs by covalent functionalization of GQDs with chiral ligands has been explored.2 Chirality can actually be transferred to a supramolecular structure built with pyrene molecules, where the chiral-GQDs/pyrene ensembles show a characteristic chiroptical response depending on the configuration of the organic ligands introduced on the GQDs structure. Furthermore, amide hydrogen bonding and π-π stacking interactions could drive the self-aggregation process to construct supramolecular polymers at the nanoscale (Figure).Within this contribution, we will present and discuss the most recent advances on the use of CDs in our group. References a) Ferrer-Ruiz, A.; Scharl, T.; Haines, P.; Rodríguez-Pérez, L.; Cadranel, A.; Herranz, M. A.; Guldi, D. M.; Martín, N. Angew. Chem. Int. Ed. 2018, 57, 1001-1005; b) Scharl, T.; Ferrer-Ruiz, A.; Saura-Sanmartín, A.; Rodríguez-Pérez, L.; Herranz, M. A.; Martín, N.; Guldi, D. M. Chem. Commun., 2019, 55, 3223-3226; c) Ferrer-Ruiz, A.; Scharl, T.; Rodríguez-Pérez, L.; Cadranel, A.; Herranz, M. A.; Martín, N.; Guldi, D. M. J. Am. Chem. Soc. 2020, 142, 20324−20328.a) Vázquez-Nakagawa, M.; Rodríguez-Pérez, L.; Herranz, M. A.; Martín, N. Chem. Commun., 2016, 52, 665-668, b) Vázquez-Nakagawa, M.; Rodríguez-Pérez, L:, Martín, N.; Herranz, M. A.; Angew. Chem. Int. Ed., 2022, 61, e202211365. Figure 1

Donor-acceptor-donor small molecules for fluorescence/photoacoustic imaging and integrated photothermal therapy.

Here, a D-A-D type fluorescent conjugated molecule with a high molar absorption coefficient and emission at 1120 nm in the near-infrared region was synthesized. Conjugated molecules and two polyethylene glycol polymers with different lipophilic ends are assembled into water-soluble nanoparticles to improve their biocompatibility. Then, their physical and chemical properties were studied and compared. Compared with phospholipid-based PEG, styrene-based PEG can reduce the π-π stacking between molecules and the quenching caused by molecular aggregation. It has more advantages in particle size and fluorescence performance and can be better used in biological imaging. In addition, the Nano-particles have good photo-thermal conversion efficiency; the temperature rises to 62.8°C after 980 nm irradiation for 6 min, which can be used as a potential near-infrared II photothermal therapeutic agent. In vivo imaging experiments confirmed that nanomaterials have fluorescence, photoacoustic dual-modal imaging and good biological safety. STATEMENT OF SIGNIFICANCE: In this work, we constructed D-A-D type dual donor fluorescent molecules using BBTD, CPDT and EDOT, and used amphiphilic polymers to improve their biocompatibility. Compared with DSPE NPs, PS-NPs can reduce intermolecular π-π stacking and increase quantum yield (QY=0.98 %). Deep penetration and low biological toxicity make it have biomedical value and realize the integration of multi-functional collaborative imaging. This work can still be further improved and supplemented, and the molecular structure can be optimized to improve its application in biomedical imaging.

Cefminox sodium carbon nanodots for treatment and bacterial detection of bloodstream infection

Cefminox sodium carbon nanodots were synthesized via a rapid one-step microwave method using cefminox sodium as sole precursor. The prepared cefminox sodium carbon nanodots had good water solubility and the diameter was concentrated at 1.29 ± 0.40 nm with relative uniform. They exhibited fluorescence excitation-dependent property, of which optimal excitation wavelength was ∼ 390 nm, and optimal emission wavelength was ∼ 465 nm. As retained part of the structure and antibacterial properties of cefminox sodium, cefminox sodium carbon nanodots had low biological toxicity and sufficient antibacterial activity against bacteria in vitro. In vivo experiments demonstrated cefminox sodium carbon nanodots could exert a good therapeutic effect on acute bloodstream infection. In the mixed solution (Escherichia coli, blood and cefminox sodium carbon nanodots), the fluorescent intensity exhibited quadratic functional relationship with the concentration of Escherichia coli. The detection concentration range for Escherichia coli was 0.5 × 106 ∼ 1 × 109 CFU/mL, and the detection limit was 3.7 × 105 CFU/mL. It suggested cefminox sodium carbon nanodots can rapidly and quantitatively detect the number of Escherichia coli in blood while effectively treating bloodstream infection. Due to the long period of clinical detection time (about 1–5 days or more) for bacterial counts in the blood of patients, this method provides a new strategy for rapid clinical treatment and effective monitoring of the degree of infection in patients.

Cancer Cell Membrane-Coated Gambogic Acid Nanoparticles for Effective Anticancer Vaccination by Activating Dendritic Cells.

Recent studies have shown that traditional Chinese medicine (TCM), such as gambogic acid (GA), is involved in the regulation of tumor immune microenvironment and can be combined with other anti-tumor treatment strategies. Here, we used GA as an adjuvant to construct a nano-vaccine to improve the anti-tumor immune response of colorectal cancer (CRC). We used a previously reported two-step emulsification method to obtain poly (lactic-co-glycolic acid) /GA nanoparticles (PLGA/GA NPs), and then CT26 colon cancer cell membrane (CCM) was used to obtain CCM-PLGA/GA NPs. This novel nano-vaccine, CCM-PLGA/GA NPs, was co-synthesized with GA as an adjuvant and neoantigen provided by CT26 CCM. We further confirmed the stability, tumor targeting, and cytotoxicity of CCM-PLGA/GA NPs.The regulatory effect on the tumor immune microenvironment, the anti-tumor efficacy, and the combined anti-tumor efficacy with anti-PD-1 monoclonal Antibodies (mAbs) of this novel nano-vaccine was also detected in vivo. We successfully constructed the CCM-PLGA/GA NPs. In vitro and in vivo tests showed low biological toxicity, as well as the high tumor-targeting ability of the CCM-PLGA/GA NPs. Besides, we revealed a remarkable effect of CCM-PLGA/GA NPs to activate the maturation of dendritic cells (DCs) and the formation of a positive anti-tumor immune microenvironment. This novel nano-vaccine constructed with GA as the adjuvant and CCM providing the tumor antigen can not only directly kill tumors by enhancing the ability of GA to target tumors, but also indirectly kill tumors by regulating tumor immune microenvironment, providing a new strategy for immunotherapy of CRC.

Ultrasonic enhancement of microdroplet-based interfacial reaction for improving the synthesis of Ag2S QDs

Ag2S quantum dots (QDs) have aroused extensive concerns in intravital imaging field due to their merits of narrow bandgap, low biological toxicity and decent fluorescence emission properties in the second near-infrared (NIR-II) window. However, low quantum yield (QY) and poor uniformity of Ag2S QDs are still main obstacles for its application. In this work, a novel strategy of utilizing ultrasonic field is presented, which can enhance the microdroplet-based interfacial synthesis of Ag2S QDs. The ultrasound increases the presence of ions at the reaction sites by enhancing the ion mobility in the microchennels. Therefore, the QY is enhanced from 2.33 % (optimal QY without ultrasound) to 8.46 %, which is the highest value of Ag2S ever reported without ion-doping. Also, the decrease of the corresponding full width at half maximum (FWHM) from 312 nm to 144 nm indicates the obvious uniformity improvement of the obtained QDs. Further mechanism exploration illustrates that ultrasonic cavitation significantly increases the interfacial reaction sites by splitting the droplets. Meanwhile, the acoustic flow field strengthens the ion renewal at the droplet interface. Consequently, the mass transfer coefficient increases by more than 500 %, which is favorable to improve both the QY and quality of Ag2S QDs. This work serves both fundamental research and practical production for the synthesis of Ag2S QDs.