Artificial Receptors Research Articles

Fully Aqueous Self-Assembly of a Gold-Nanoparticle-Based Pathogen Sensor.

Surface plasmon resonance (SPR) is a very sensitive measure of biomolecular interactions but is generally too expensive for routine analysis of clinical samples. Here we demonstrate the simplified formation of virus-detecting gold nanoparticle (AuNP) assemblies on glass using only aqueous buffers at room temperature. The AuNP assembled on silanized glass and displayed a distinctive absorbance peak due to the localized SPR (LSPR) response of the AuNPs. Next, assembly of a protein engineering scaffold was followed using LSPR and a sensitive neutron reflectometry approach, which measured the formation and structure of the biological layer on the spherical AuNP. Finally, the assembly and function of an artificial flu sensor layer consisting of an in vitro-selected single-chain antibody (scFv)-membrane protein fusion was followed using the LSPR response of AuNPs within glass capillaries. In vitro selection avoids the need for separate animal-derived antibodies and allows for the rapid production of low-cost sensor proteins. This work demonstrates a simple approach to forming oriented arrays of protein sensors on nanostructured surfaces that uses (i) an easily assembled AuNP silane layer, (ii) self-assembly of an oriented protein layer on AuNPs, and (iii) simple highly specific artificial receptor proteins.

Notch1 signaling is limited in healthy mature kidneys in vivo

ObjectiveA Delta-Notch signaling component, Notch1, is involved in the normal development and multiple disorders of the kidney. Although the increase in Notch1 signaling is crucial to these pathogeneses, the basal signaling level in ‘healthy’ mature kidneys is still unclear. To address this question, we used an artificial Notch1 receptor fused with Gal4/UAS components in addition to the Cre/loxP system and fluorescent proteins in mice. This transgenic reporter mouse system enabled labeling of past and ongoing Notch1 signaling with tdsRed or Cre recombinase, respectively.ResultsWe confirmed that our transgenic reporter mouse system mimicked the previously reported Notch1 signaling pattern. Using this successful system, we infrequently observed cells with ongoing Notch1 signaling only in Bowman’s capsule and tubules. We consider that Notch1 activation in several lines of disease model mice was pathologically significant itself.

Lysozyme Imprinted poly(hydroxyethyl methacrylate) Cryogel Membrane with the Assistance of polydopamine

The surface imprinted technique was utilized in creating the synthetic lysozyme receptors on the poly(hydroxyethyl methacrylate) [p(HEMA)] cryogel membrane with the assistance of polydopamine under alkaline conditions. Following the design of the artificial receptors, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and the swelling test were used for the characterization studies and the lysozyme adsorption capability of the adsorbent was evaluated in the aqueous solution. The maximum adsorption capacity (Qmax) of lysozyme was found as 108.9 mg/g and the adsorption of the target protein on the adsorbent was monolayer and showed a good fit to the Langmuir isotherm model. The IF factor was 3.26 and the adsorbent was highly selective against creatinine and bovine serum albumin (BSA). Furthermore, the adsorbent maintained its stability after 5 adsorption, desorption, and regeneration cycles.

Targeting CD19 and CD22 with CAR-T cell therapy in acute lymphoid leukemia

Acute lymphoid leukemia (ALL) was usually occurred in children. It accounted for 75% of all acute leukemias. In other words, it accounted for 35 percent of all cancers in the same age group, especially Caucasian children. CAR-T cell therapy was an resultful treatment for ALL patients.CARs were artificial receptors. Their function was primarily to target lymphocytes, most commonly T cells, recognizing and eliminating cells that express specifically targeted antigens. There were some targets for CAR-T, such as CD19 and CD22. When treated with common methods, the prognosis of recurrent ALL after allotransplantation was frustrating. In specific the cell of CAR-T with CD19, B-ALL treatment was highly successful, 70 to 94% in a complete response (CR). therapy with CD19 and CD22 was targeted when treating refractory/relapse(R/R) B-ALL achieved high CR, most of patients couldn’t maintain enduring remission. This therapy was a huge success in curing leukemia, up to 60% of patients with this therapy relapse. To extend the period of recurrence-free survival, people targeted CD22 or CD19 antigen expression, respectively, treating relapse B-ALL patient after transplant treatment. The CR rate in single therapy with the first round achieved 85%. After that, among patients who completed CAR-T with CD19 and CD22, 88.5% and 67.5% were OS and EFS, respectively, between 12 and 18 months. The new strategy significantly improved treatment outcomes. In the future, the key of the research was shift to strategies with minimal cytotoxic chemotherapy and hematopoietic stem cell transplantation, and we hope can treat tumor successfully.

CAR T-Cell Therapy: Current Progress, Challenges and potential Strategies

In recent years, the unexpected development of immune system resistance in cancer cells has initiated development for new drug therapies that combat resistant cancer cells. One important issue is the mutation of antigens, which are able to help the cancer cells avoid immune system detection. As a result, the development of effective new therapies free from these problems is still a heavy focus in the medical community. Chimeric Antigen Receptor T-cells therapy is a new potential treatment that uses the infusion of genetically engineered immune system T-cells to recognize specific threats with the help of artificial T-cell receptors. Through extracting and engineering the blood sample of patients, foreign pathogens and cancer cells that aren’t yet able to be identified by the immune system can be recognized and detected by the CAR T-cells. This review paper aims to examine CAR T-cell treatments against ALL, focusing on the target antigens used in CAR design, variations in CAR generations, clinical trials and FDA approvals for CAR T-cells, obstacles in CAR T-cell treatments, and the best ways to overcome them.

Rapid detection of Ag+ in food using cholesteric chiral artificial receptor L5

A cholesteric chiral artificial receptor L5 was synthesized, which recognized and cooperated with Ag+ in metal ions, and a rapid method for detecting Ag+ was established in food. It was found by fluorescence spectroscopy analysis that the L5 could recognize Ag+ in DMSO solution; with the help of fluorescence and UV titration, job test and interference test to verify its recognition pattern, and founded that the L5 and guest Ag+ were combined with 1:1 coordination ratio. Then, the recognition mechanism between L5 and guest Ag+ was explored by measures of nuclear magnetic titration, infrared spectroscopy, electron microscopy and computer molecular simulation. It was speculated that the carbonyl oxygen atom near the amide of the MeO-PhCONH group and the carbonyl oxygen atom of the –COOCH3 group cooperated with Ag+ throµgh electrostatic gravitational interaction. This method was used to establish the detection of Ag+ in food in which the detection limit of L5 for Ag+ was derived as 0.13 µmol/L, and the silver ions in wolfberry, milk powder,wheat flour, tea leaf and soybean were accurately detected. This method can be used to quantify Ag+ content in actual samples accurately and efficiently.

Tunable Fluorescent Artificial Receptor Biosensor Based on Programmable Lanthanide Metal‐Organic Framework for Highly Selective Neurotransmitter Detection

AbstractThe design and fabrication of artificial receptors suitable for highly selective and sensitive sensing of neurotransmitters in aqueous media remains a challenge, especially for the significant biomarker dopamine (DA) for neurological diseases. Herein, a novel modular fluorescent artificial receptor design strategy based on multiple parameters programming engineering is proposed. The optimal artificial receptor DA biosensor based on fluorescent lanthanide metal‐organic frameworks (Ln‐MOFs) is coded by adjusting the modular design parameters such as preparation solvents and ligands. It is prepared by Eu ion and ligand 1,2,4,5‐benzenetetracarboxylic acid (BTEC) in DMF/water, which can selectively recognize DA even in complex biological fluids, without the interference of other structurally similar neurotransmitters such as levodopa, serotonin and noradrenaline, and the limit of detection for DA is as low as 10 nm. Ln‐MOFs are believed to uniquely utilize their tunable host‐guest interactions (specific recognition) and confinement catalysis capabilities to achieve highly selective and dual‐response DA detection, similar to lock‐and‐key theory, which is supported by experiments and density functional theory calculations. Fluorescent artificial receptors based on Ln‐MOFs are proved to have broad potential for label‐free detection, imaging and diagnosis. They can overcome the long‐standing limitations of complex synthetic biosensors, and bringing new solutions to personalized medicine.

Molecular imprinting based on metal-ion mediated recognition: Electrosynthesis of artificial receptors for the selective detection of peptides

We describe the electrosynthesis of a molecularly imprinted polymer (MIP) based on a metallo-porphyrin, namely Zn(II)− 5,10,15,20-tetrakis-(p-aminophenyl)-porphyrin (ZnTAPP), as a new artificial receptor for the recognition of carnosine (β-Ala--His), used as a model dipeptide. The MIP architecture has been selected with the aim to exploit metal-ion mediated recognition leveraging carnosine ability to chelate metal ions as Zn(II) through its histidine moiety. Metal ion coordination in imprinting procedures is beneficial as it combines the flexibility of noncovalent approach with the strength and specificity of covalent one representing an attractive hybrid imprinting strategy. MIP assembly was monitored by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) both showing MIP deposition on the electrode as well as template removal. FT-IR analysis confirmed carnosine entrapment within the electrosynthesized Zn-porphyrin, further confirmed by XPS characterization which also demonstrated a significant metal removal from polymer film upon treatment with EDTA. Interestingly, no significant EIS response was monitored on the as-treated film, revealing no carnosine rebinding in the absence of metal ion. High response specificity has instead emerged by EIS measurements on MIP as well as a good time stability and a remarkable selectivity with little or no cross-reactivity with other peptides, including histidine-bearing ones and peptides with high structural similarity. Tests in lysates from human neuron-derived cells revealed sensor applicability in real samples analysis. This strategy allows to achieve excellent analytical performances with high versatility being possibly expandable to the detection of any histidine-bearing molecules as aminoacids, peptides and proteins, and also to any target molecule able to interact with Zn(II) ions.

Fabrication of a Lactate-Specific Molecularly Imprinted Polymer toward Disease Detection.

The development of sensitive and selective robust sensor materials for targeted biomarker detection aims to contribute to self-health monitoring and management. Molecularly imprinted polymeric (MIP) materials can perform as biomimetic recognition elements via tailored routes of synthesis for specific target analyte extraction and/or detection. In this work, a sensitive- and selective-lactate MIP has been developed utilizing methacrylic acid and ethylene glycol dimethacrylate as the functional monomer and cross-linker, respectively. The sensitivity of the as-synthesized imprinted species was evaluated by determining the target analyte retention, imprinting factor, and selectivity adsorption of up to 63.5%, 6.86, and 0.82, respectively. MIP selectivity elucidated the imprinting mechanism between the functional monomers and target analyte lactate, further experimentally evidenced by using structurally competitive analytes malic acid and sodium 2-hydroxybutyrate, where retentions of 22.6 and 25.2%, respectively, were observed. Understanding the specific intermolecular mechanisms of both the template analyte and structural interferents with the MIP enables experimentalists to make informed decisions regarding monomer-target and porogen selections and possible sites of interaction for improved molecular imprinting. This imprinting system highlights the potential to be further developed into artificial receptor sensor materials for the detection of disease.

Supramolecular Recognition of Cytidine Phosphate in Nucleotides and RNA Sequences.

Supramolecular recognition of nucleotides would enable manipulating crucial biochemical pathways like transcription and translation directly and with high precision. Therefore, it offers great promise in medicinal applications, not least in treating cancer or viral infections. This work presents a universal supramolecular approach to target nucleoside phosphates in nucleotides and RNA. The artificial active site in new receptors simultaneously realizes several binding and sensing mechanisms: encapsulation of a nucleobase via dispersion and hydrogen bonding interactions, recognition of the phosphate residue, and a self-reporting feature-"turn-on" fluorescence. Key to the high selectivity is the conscious separation of phosphate- and nucleobase-binding sites by introducing specific spacers in the receptor structure. We have tuned the spacers to achieve high binding affinity and selectivity for cytidine 5' triphosphate coupled to a record 60-fold fluorescence enhancement. The resulting structures are also the first functional models of poly(rC)-binding protein coordinating specifically to C-rich RNA oligomers, e.g., the 5'-AUCCC(C/U) sequence present in poliovirus type 1 and the human transcriptome. The receptors bind to RNA in human ovarian cells A2780, causing strong cytotoxicity at 800 nM. The performance, self-reporting property, and tunability of our approach open up a promising and unique avenue for sequence-specific RNA binding in cells by using low-molecular-weight artificial receptors.

An ultra-sensitive dopamine measurement platform based on molecularly imprinted polymer-carbon hybrid nanomaterials for in vitro use

In the present study, we designed an ultrasensitive sensing platform for the evaluation of the physiologically relevant values of basal dopamine (DA) in a culture medium as a complex biological environment. The proposed sensing platform was fabricated via the integration of molecular imprinting technology with carbon hybrid nanomaterials. Carbon nanofibers (CNFs) were grown by using plasma-enhanced chemical vapor deposition (PECVD) on tetrahedral amorphous carbon (ta-C) thin films on silicon wafers. The prepared ta-C/CNFs sensing platforms were electrochemically coated with DA-imprinted polypyrrole as the molecularly imprinted polymer (MIP) or "artificial receptors". The three-dimensional MIP receptors were able to determine trace values of DA in phosphate-buffered saline solution (PBS) pH 7.4 (LOD = 5.43 nM) as well as in the absolute culture media such as DMEM/F-12 medium (LOD = 39 nM), DMEM/F-12 medium supplemented with 15% horse serum and 2.5% fetal bovine serum (LOD = 53.26 nM), and F-12 K cell culture medium (LOD = 62.57 nM), with highly physiologically relevant sensitivity and free of interference by other coexisting biomolecules and biological compounds. As all the fabrication steps of the composite electrode are compatible with common microsystem technology processes, the present results pave the way for integrating these ultra-sensitive electrodes to microelectrode arrays (MEA) platforms used for human dopaminergic neurons studies in vitro and enable continuous measurement of the basal DA concentration in real-time for instance in organoid studies.

DNA‐Incorporated Biomimetic Olfactory Neuroepithelium That Facilitates Artificial Intelligence

Designing biomimetic olfactory neuroepithelium (BONe) with subnanosized active domains as artificial olfactory receptors (ORs) is highly desirable to sense various colorless and odorless hazardous odorants which find no appropriate ORs in the human olfactory neuroepithelium (ONe), yet challenging because of the unsuitability of biomolecules for a design that requires effective electronic features and stability. Herein, a DNA‐incorporated 3D BONe is introduced, where DNA facilitates optimal tuning of d‐band center, and in situ anchoring of PdO2 subnanoscale clusters (PdO2‐sNCs) on the exfoliated single‐layer reduced graphene oxide (SL rGO), to mimic wrinkled morphology of natural ONe. Unprecedentedly, BONe demonstrates benchmarked H2‐sensing performance (small recovery time of ≈30 s with a limit of detection of 50 ppb) at room temperature with yearlong durability, satisfying prerequisites of safe adoption of H2 clean energy. The great recovery is innovatively illustrated by the downshift of d‐band center of PdO2‐sNCs and strong electron transport of SL‐rGO network. An adsorption/desorption model is proposed to clarify the sensing mechanism. BONe design may eventually be integrated with artificial intelligent electronics for ppb‐level sensing of harmful gases to ensure accident prevention in modern public and military environments.

Resorc[4]arene-Modified Gold-Decorated Magnetic Nanoparticles for Immunosensor Development.

In recent years, several efforts have been made to develop selective, sensitive, fast response, and miniaturized immunosensors with improved performance for the monitoring and screening of analytes in several matrices, significantly expanding the use of this technology in a broad range of applications. However, one of the main technical challenges in developing immunosensors is overcoming the complexity of binding antibodies (Abs) to the sensor surface. Most immobilizing approaches lead to a random orientation of Abs, resulting in lower binding site density and immunoaffinity. In this context, supramolecular chemistry has emerged as a suitable surface modification tool to achieve the preorganization of artificial receptors and to improve the functional properties of self-assembled monolayers. Herein, a supramolecular chemistry/nanotechnology-based platform was conceived to develop sensitive label-free electrochemical immunosensors, by using a resorcarene macrocycle as an artificial linker for the oriented antibody immobilization. To this aim, a water-soluble bifunctional resorc[4]arene architecture (RW) was rationally designed and synthesized to anchor gold-coated magnetic nanoparticles (Au@MNPs) and to maximize the amount of the active immobilized antibody (Ab) in the proper "end-on" orientation. The resulting supramolecular chemistry-modified nanoparticles, RW@Au@MNPs, were deposited onto graphite screen printed electrodes which were then employed to immobilize three different Abs. Furthermore, an immunosensor for atrazine (ATZ) analysis was realized and characterized by the differential pulse voltammetry technique to demonstrate the validity of the developed biosensing platform as a proof of concept for electrochemical immunosensors. The RW-based immunosensor improved AbATZ loading on Au@MNPs and sensitivity toward ATZ by almost 1.5 times compared to the random platform. Particularly, the electrochemical characterization of the developed immunosensor displays a linearity range toward ATZ within 0.05-1.5 ng/mL, a limit of detection of 0.011 ng/ml, and good reproducibility and stability. The immunosensor was tested by analyzing spiked fortified water samples with a mean recovery ranging from 95.7 to 108.4%. The overall good analytical performances of this immunodevice suggest its application for the screening and monitoring of ATZ in real matrices. Therefore, the results highlighted the successful application of the resorc[4]arene-based sensor design strategy for developing sensitive electrochemical immunosensors with improved analytical performance and simplifying the Ab immobilization procedure.

Chimeric antigen receptor-based therapies beyond cancer.

Adoptive cell transfer (ACT) therapies have gained renewed interest in the field of immunotherapy following the advent of chimeric antigen receptor (CAR) technology. This immunological breakthrough requires immune cell engineering with an artificial surface protein receptor for antigen-specific recognition coupled to an intracellular protein domain for cell activating functions. CAR-based ACT has successfully solved some hematological malignancies, and it is expected that other tumors may soon benefit from this approach. However, the potential of CAR technology is such that other immune-mediated disorders are beginning to profit from it. This review will focus on CAR-based ACT therapeutic areas other than oncology such as infection, allergy, autoimmunity, transplantation, and fibrotic repair. Herein, we discuss the results and limitations of preclinical and clinical studies in that regard.

A Clinically Viable Approach to Cell Programming

A Clinically Viable Approach to Cell Programming

Driving the Chimeric Antigen Receptor: The Road Ahead for Cell Therapy

Driving the Chimeric Antigen Receptor: The Road Ahead for Cell Therapy

Molecularly Imprinted Polymer-Based Sensors for Protein Detection.

The accurate detection of biological substances such as proteins has always been a hot topic in scientific research. Biomimetic sensors seek to imitate sensitive and selective mechanisms of biological systems and integrate these traits into applicable sensing platforms. Molecular imprinting technology has been extensively practiced in many domains, where it can produce various molecular recognition materials with specific recognition capabilities. Molecularly imprinted polymers (MIPs), dubbed plastic antibodies, are artificial receptors with high-affinity binding sites for a particular molecule or compound. MIPs for protein recognition are expected to have high affinity via numerous interactions between polymer matrices and multiple functional groups of the target protein. This critical review briefly describes recent advances in the synthesis, characterization, and application of MIP-based sensor platforms used to detect proteins.

Synthesis of fluorescent artificial receptors with high specificity for simultaneous detection of non-steroidal anti-inflammatory drugs

Development of multiple detection methods to monitor non-steroidal anti-inflammatory drugs (NSAIDs) in food is an effective way to protect human health. Here, we aimed to synthesize fluorescent artificial receptors by molecular imprinting technique to construct a simultaneous detection system targeting NSAIDs. Rhodamine B and fluorescein-functionalized silanes were employed as the fluorescence signal reporters for naproxen and ketoprofen, respectively. Two fluorescent molecularly imprinted polymers (FMIPs) were obtained with high specificity, giving cross-reactivity factors of 6.4–15.8 (naproxen) and 2.6–25.6 (ketoprofen). Both FMIPs also displayed rapid response time (5 min) and high sensitivity (detection limit at ∼ nM level). A simultaneous detection system was constructed based on the FMIPs and applied for sensing the spiked NSAIDs in real samples, showing recoveries of 71–119 %, comparable with the HPLC methods (70–113 %). In summary, use of different FMIPs to construct simultaneous detection systems is practicable, and provides a flexible way for sensing multiple hazards in food samples.

Carbohydrate recognition using metal-ligand assemblies.

Carbohydrate-binding proteins, known as lectins, play a wide range of vital roles in cellular and pathological processes. Mimicking lectins to achieve specific molecular recognition of carbohydrates in organic and aqueous media using artificial receptors is challenging due to the synthetic hurdles of receptors and structural similarities between sugars. Carbohydrate recognition using non-covalent interactions remains a vast topic. This review summarises the recognition of carbohydrates using metal-ligand assemblies, including metallosupramolecules, macrocycles, and cages. It also highlights the challenges and future directions in the field.

Gold nanoshells with magnetic cores and a urea-based receptor for SERS sensing of fluoride anions: experimental and computational study.

The study demonstrates that a combination of plasmonic nanostructures and artificial receptors can be applied for sensing small molecular species. Gold nanoshells containing magnetic cores are used as the SERS-active substrates, which opens the way for the development of multimodal contrast agents with applicability extended to sensing or for the separation of analytes by magnetic solid-phase extraction. Disubstituted ureas forming hydrogen-bonded complexes with certain anions can be employed as molecular sensors. In this case study, gold nanoshells with silica-coated Mn-Zn ferrite cores were prepared by a multistep procedure. The nanoshells were co-functionalized with an N-(4-mercaptophenyl)-N'-(4-nitrophenyl)urea sensor synthesized directly on the gold surface, and with 4-nitrothiophenol, which is adopted as an internal standard. SERS measurements were carried out with acetonitrile solutions of tetrabutylammonium fluoride (Bu4NF) over a concentration range of 10-10-10-1 mol L-1. The spectral response of the sensor is dependent on the fluoride concentration in the range of 10-5-10-1 mol L-1. To investigate further the SERS mechanism, a model sensor, N-(4-bromophenyl)-N'-(4-nitrophenyl)urea, was synthesized and used in Raman spectroscopy with solutions of Bu4NF, up to a molar ratio of 1 : 20. The spectra and the interactions between the sensors and fluoride anions were also studied by extensive DFT computations.