Terminal deoxynucleotidyl transferase-mediated formation of protein binding polynucleotides.

Terminal deoxynucleotidyl transferase (TdT) enzyme plays an integral part in the V(D)J recombination, allowing for the huge diversity in expression of immunoglobulins and T-cell receptors within lymphocytes, through their unique ability to incorporate single nucleotides into oligonucleotides without the need of a template. The role played by TdT in lymphocytes precursors found in early vertebrates is not known. In this paper, we demonstrated a new screening method that utilises TdT to form libraries of variable sized (vsDNA) libraries of polynucleotides that displayed binding towards protein targets. The extent of binding and size distribution of each vsDNA library towards their respective protein target can be controlled through the alteration of different reaction conditions such as time of reaction, nucleotide ratio and initiator concentration raising the possibility for the rational design of aptamers prior to screening. The new approach, allows for the screening of aptamers based on size as well as sequence in a single round, which minimises PCR bias. We converted the protein bound sequences to dsDNA using rapid amplification of variable ends assays (RAVE) and sequenced them using next generation sequencing. The resultant aptamers demonstrated low nanomolar binding and high selectivity towards their respective targets.

An Optimally Designed Engineering Exosome-Reductive COF Integrated Nanoagent for Synergistically Enhanced Diabetic Fester Wound Healing.

Oxidative stress and local overactive inflammation have been considered major obstacles in diabetic wound treatment. Although antiphlogistic tactics have been reported widely, they are also challenged by pathogen contamination and compromised angiogenesis. Herein, a versatile integrated nanoagent based on 2D reductive covalent organic frameworks coated with antibacterial immuno-engineered exosome (PCOF@E-Exo) is reported to achieve efficient and comprehensive combination therapy for diabetic wounds. The E-Exo is collected from TNF-α-treated mesenchymal stem cells (MSCs) under hypoxia and encapsulated cationic antimicrobial carbon dots (CDs). This integrated nanoagent not only significantly scavenges reactive oxygen species and induces anti-inflammatory M2 macrophage polarization, but also stabilizes hypoxia-inducible factor-1α (HIF-1α). More importantly, the PCOF@E-Exo exhibits intriguing bactericide capabilities toward Gram-negative, Gram-positive, and drug-resistant bacteria, showing favorable intracellular bacterial destruction and biofilm permeation. In vivo results demonstrate that the synergetic impact of suppressing oxidative injury and tissue inflammation, promoting angiogenesis and eradicating bacterial infection, could significantly accelerate the infected diabetic fester wound healing with better therapeutic benefits than monotherapy or individual antibiotics. The proposed strategy can inspire further research to design more delicate platforms using the combination of immunotherapy with other therapeutic methods for more efficient ulcerated diabetic wounds treatments.

Synthesis of graphene quantum dots and their applications in drug delivery.

This review focuses on the recent advances in the synthesis of graphene quantum dots (GQDs) and their applications in drug delivery. To give a brief understanding about the preparation of GQDs, recent advances in methods of GQDs synthesis are first presented. Afterwards, various drug delivery-release modes of GQDs-based drug delivery systems such as EPR-pH delivery-release mode, ligand-pH delivery-release mode, EPR-Photothermal delivery-Release mode, and Core/Shell-photothermal/magnetic thermal delivery-release mode are reviewed. Finally, the current challenges and the prospective application of GQDs in drug delivery are discussed.

ß-Hydroxybutyrate dehydrogenase decorated MXene nanosheets for the amperometric determination of ß-hydroxybutyrate.

MXene nanosheets of type Ti3C2Tx were modified with ß-hydroxybutyrate dehydrogenase and then used as a biosensor for amperometric sensing of ß-hydroxybutyrate. The MXene and the nanocomposite were characterized by X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The MXene has a layered structure and proved to be an excellent immobilization matrix providing good compatibility with the enzyme ß-hydroxybutyrate dehydrogenase. The MXene-based biosensor, best operated at a potential of - 0.35 V (vs. Ag/AgCl), displays a wide linear range (0.36 to 17.9 mM), a sensitivity of 0.480 µA mM-1 cm-2, and a low detection limit (45 µM). The biosensor was successfully applied to the determination of ß-hydroxybutyrate in (spiked) real serum samples. Graphical abstract Schematic representation of the synthesis and decoration of Mxene 2D sheets with ß-hydroxybutyrate dehydrogenase for the amperometric determination of ß-hydroxybutyric acid.

Robust Bioengineered Apoferritin Nanoprobes for Ultrasensitive Detection of Infectious Pancreatic Necrosis Virus.

Infectious pancreatic necrosis virus (IPNV) has been identified as a viral pathogen for many fish diseases that have become a huge hurdle for the growing fishing industry. Thus, in this work, we report a label-free impedance biosensor to quantify IPNV in real fish samples at point-of-care (POC) level. High specificity IPNV sensor with a detection limit of 2.69 TCID50/mL was achieved by conjugating IPNV antibodies to portable Au disk electrode chips using human heavy chain apoferritin (H-AFN) nanoprobes as a binding agent. H-AFN probes were bioengineered through PCR by incorporating pET-28b(+) resulting in 24 subunits of 6 × his-tag and protein-G units on its outer surface to increase the sensitivity of the IPNV detection. The biosensor surface modifications were characterized by differential pulse voltammetry (DPV) and EIS methods for each modification step. The proposed nanoprobe based sensor showed three-fold enhancement in charge transfer resistance toward IPNV detection in comparison with the traditional linker approach when measured in a group of similar virus molecules. The portable sensor exhibited a linear range of 100-10000 TCID50/mL and sensitivity of 5.40 × 10-4 TCID50/mL in real-fish samples. The performance of the proposed IPNV sensor was fully validated using an enzyme-linked immunosorbent assay (ELISA) technique with a sensitivity of 3.02 × 10-4 TCID50/mL. Results from H-AFN nanoprobe based IPNV sensor indicated high selectivity, sensitivity, and stability could be a promising platform for the detection of similar fish viruses and other biological molecules of interest.

Electrochemical Biosensor Composed of Silver Ion-Mediated dsDNA on Au-Encapsulated Bi2 Se3 Nanoparticles for the Detection of H2 O2 Released from Breast Cancer Cells.

A newly developed electrochemical biosensor composed of a topological insulator (TI) and metallic DNA (mDNA) is fabricated. The bismuth selenide nanoparticle (Bi2 Se3 NP) is synthesized and sandwiched between the gold electrode and another Au-deposited thin layer (Bi2 Se3 @Au). Then, eight-silver-ion mediated double-stranded DNA (mDNA) is immobilized onto the substrate (Bi2 Se3 @Au-mDNA) for the further detection of hydrogen peroxide. The Bi2 Se3 NP acts as the electrochemical-signal booster, while unprecedentedly its encapsulation by the Au thin layer keeps the TI surface states protected, improves its electrochemical-signal stability and provides an excellent platform for the subsequent covalent immobilization of the mDNA through Au-thiol interaction. Electrochemical results show that the fabricated biosensor represents much higher Ag+ redox current (≈10 times) than those electrodes prepared without Bi2 Se3 @Au. The characterization of the Bi2 Se3 @Au-mDNA film is confirmed by atomic force microscopy, scanning tunneling microscopy, and cyclic voltammetry. The proposed biosensor shows a dynamic range of 00.10 × 10-6 m to 27.30 × 10-6 m, very low detection limit (10 × 10-9 m), unique current response (1.6 s), sound H2 O2 recovery in serum, and substantial capability to classify two breast cancer subtypes (MCF-7 and MDA-MB-231) based on their difference in the H2 O2 generation, offering potential applications in the biomedicine and pharmacology fields.

Bifunctional Au@Bi2 Se3 Core-Shell Nanoparticle for Synergetic Therapy by SERS-Traceable AntagomiR Delivery and Photothermal Treatment.

For the first time, topological insulator bismuth selenide nanoparticles (Bi2 Se3 NP) are core-shelled with gold (Au@Bi2 Se3 ) i) to represent considerably small-sized (11 nm) plasmonic nanoparticles, enabling accurate bioimaging in the near-infrared region; ii) to substantially improve Bi2 Se3 biocompatibility, iii) water dispersibility, and iv) surface functionalization capability through straightforward gold-thiol interaction. The Au@Bi2 Se3 is subsequently functionalized for v) effective targeting of SH-SY5Y cancer cells, vi) disrupting the endosome/lysosome membrane, vii) traceable delivery of antagomiR-152 and further synergetic oncomiR knockdown and photothermal therapy (PTT). Unprecedentedly, it is observed that the Au shell thickness has a significant impact on evoking the exotic plasmonic features of Bi2 Se3 . The Au@Bi2 Se3 possesses a high photothermal conversion efficiency (35.5%) and a remarkable surface plasmonic effect (both properties are approximately twofold higher than those of 50 nm Au nanoparticles). In contrast to the siRNA/miRNA delivery methods, the antagomiR delivery is based on strand displacement, in which the antagomiR-152 is displaced by oncomiR-152 followed by a surface-enhanced Raman spectroscopy signal drop. This enables both cancer cell diagnosis and in vitro real-time monitoring of the antagomiR release. This selective PTT nanoparticle can also efficiently target solid tumors and undergo in vivo PTT, indicating its potential clinical applications.

Fabrication of Electrochemical-Based Bioelectronic Device and Biosensor Composed of Biomaterial-Nanomaterial Hybrid.

The field of bioelectronics has paved the way for the development of biochips, biomedical devices, biosensors and biocomputation devices. Various biosensors and biomedical devices have been developed to commercialize laboratory products and transform them into industry products in the clinical, pharmaceutical, environmental fields. Recently, the electrochemical bioelectronic devices that mimicked the functionality of living organisms in nature were applied to the use of bioelectronics device and biosensors. In particular, the electrochemical-based bioelectronic devices and biosensors composed of biomolecule-nanoparticle hybrids have been proposed to generate new functionality as alternatives to silicon-based electronic computation devices, such as information storage, process, computations and detection. In this chapter, we described the recent progress of bioelectronic devices and biosensors based on biomaterial-nanomaterial hybrid.

Genetically edited T-cell membrane coated AIEgen nanoparticles effectively prevents glioblastoma recurrence.

Glioblastoma stem cells (GSCs) are subpopulations of tumor-initiating cells responsible for glioblastoma (GBM) tumorigenesis and recurrence. Dual inhibition of vascular endothelium and GSCs is still a challenge due to their different pathological features. Here we present a combined all-in-control strategy to realize a local photothermal therapy (PTT). We designed T-cell-mimic nanoparticles with aggregation-induced emission (AIE) characteristics by coating the genetically engineered T cell membrane (CM) onto AIE nanoparticles (CM@AIE NPs). The CM shell was designed against CD133 and epidermal growth factor receptor (EGFR) which provides the possibility to target both GBM cells and GSCs for cancer therapy. CM@AIE NPs can serve as the tight junction (TJ) modulators to trigger an intracellular signaling cascade, causing TJ disruption and actin cytoskeleton reorganization to allow CM@AIE NPs to cross the blood-brain barrier (BBB) silently. The 980 nm excitation-triggered PTT can completely inhibit tumorigenesis and recurrence. The combination of CM-coating nanotechnology and genetic editing technique can inspire further development of synergetic techniques for preventing GBM recurrence.

Anti-MicroRNA-21 Oligonucleotide Loaded Spermine-Modified Acetalated Dextran Nanoparticles for B1 Receptor-Targeted Gene Therapy and Antiangiogenesis Therapy.

The use of nanoparticles (NPs) to deliver small inhibiting microRNAs (miRNAs) has shown great promise for treating cancer. However, constructing a miRNA delivery system that targets brain cancers, such as glioblastoma multiforme (GBM), remains technically challenging due to the existence of the blood-tumor barrier (BTB). In this work, a novel targeted antisense miRNA-21 oligonucleotide (ATMO-21) delivery system is developed for GBM treatment. Bradykinin ligand agonist-decorated spermine-modified acetalated dextran NPs (SpAcDex NPs) could temporarily open the BTB by activating G-protein-coupled receptors that are expressed in tumor blood vessels and tumor cells, which increase transportation to and accumulation in tumor sites. ATMO-21 achieves high loading in the SpAcDex NPs (over 90%) and undergoes gradual controlled release with the degradation of the NPs in acidic lysosomal compartments. This allows for cell apoptosis and inhibition of the expression of vascular endothelial growth factor by downregulating hypoxia-inducible factor (HIF-1α) protein. An in vivo orthotopic U87MG glioma model confirms that the released ATMO-21 shows significant therapeutic efficacy in inhibiting tumor growth and angiogenesis, demonstrating that agonist-modified SpAcDex NPs represent a promising strategy for GBM treatment combining targeted gene therapy and antiangiogenic therapy.

Brain-targeted antigen-generating nanoparticles improve glioblastoma prognosis.

The exploration of multifunctional nanomedicine has prompted interest in improving glioblastoma (GBM) prognosis. In this study, we constructed tumor microenvironment (TME)-responsive magnetic therapeutic nanoparticles (BK@MTNPs) as a multifunctional drug delivery platform. It contains the following components. [Des-arg(Sheets et al., 2020 [9])]bradykinin (BK), which contributes to the transient opening of the blood-brain barrier (BBB) and targeting of GBM cells; nanoparticles (NPs) encapsulated in MTNPs, which act as an in vivo magnetic resonance (MR) imaging agent; crizotinib, which is an inhibitor of protein kinase c-Met; and the immune drug anti-PDL1 antibody. These components were loaded into BK@MTNPs for complete tumoricidal effects. Abundant glutathione in the TME can promote BK@MTNP degradation by interrupting the disulfide bonds between cysteine residues. Such BK@MTNPs support a synergistic tumoricidal effect by inducing DNA damage, activating the transcription of the tumor suppressor gene PTEN, inhibiting glioblastoma stem cell function, activating cytotoxic T lymphocytes, and reprogramming tumor-associated macrophages. BK@MTNPs showed a significant increase in antitumor activity compared with free drugs in vitro. Furthermore, in mice bearing orthotopic GBM, treatment with BK@MTNPs resulted in marked tumor inhibition and greatly extended survival time with minimal side effects. This study demonstrates the advantages of chemo-immunotherapeutic NPs accumulated in the GBM area and their effective inhibition of GBM growth, thus establishing a delivery platform to promote antitumor immunity against GBM.

Dual enzyme-mimic nanozyme based on single-atom construction strategy for photothermal-augmented nanocatalytic therapy in the second near-infrared biowindow.

Nanozyme-based catalytic therapy, an emerging therapeutic pattern, has significantly incorporated in the advancement of tumor therapy by generating lethal reactive oxygen species. Nevertheless, most of the nanozymes have mono catalytic performances with H2O2 in the tumor microenvironment (TME), which lowers their therapeutic efficiency. Herein, we design a newly-developed single-atom Fe dispersed N-doped mesoporous carbon nanospheres (SAFe-NMCNs) nanozyme with high H2O2 affinity for photothermal-augmented nanocatalytic therapy. The SAFe-NMCNs nanozyme possesses dual enzyme-mimic catalytic activity which not only acts as a catalase-mimic role to achieve ultrasonic imaging in tumor site by O2 generation, but also exhibits the superior peroxidase-mimic catalytic performance to generate •OH for nanocatalytic therapy. Besides, the SAFe-NMCNs nanozyme with strong optical absorption in the second near-infrared (NIR-II) region shows excellent photothermal conversion performance. The peroxidase-mimic catalytic process of SAFe-NMCNs nanozyme is realized using density functional theory (DFT). Both in vitro and in vivo results indicate that the SAFe-NMCNs nanozyme can efficiently suppress tumor cells growth by a synergistic therapy effect with photothermal-augmented nanocatalytic therapy. The work developed a single-atom-coordinated nanozyme with dual-enzyme catalytic performance and achieve hyperthermia-augmented nanocatalytic therapy effect, can open a window for potential biological applications.

Upregulating Aggregation-Induced-Emission Nanoparticles with Blood-Tumor-Barrier Permeability for Precise Photothermal Eradication of Brain Tumors and Induction of Local Immune Responses.

Compared to other tumors, glioblastoma (GBM) is extremely difficult to treat. Recently, photothermal therapy (PTT) has demonstrated advanced therapeutic efficacy; however, because of the relatively low tissue-penetration efficiency of laser light, its application in deep-seated tumors remains challenging. Herein, bradykinin (BK) aggregation-induced-emission nanoparticles (BK@AIE NPs) are synthesized; these offer selective penetration through the blood-tumor barrier (BTB) and strong absorbance in the near-infrared region (NIR). The BK ligand can prompt BTB adenosine receptor activation, which enhances transportation and accumulation inside tumors, as confirmed by T1 -weighted magnetic resonance and fluorescence imaging. The BK@AIE NPs exhibit high photothermal conversion efficiency under 980 nm NIR laser irradiation, facilitating the treatment of deep-seated tumors. Tumor progression can be effectively inhibited to extend the survival span of mice after spatiotemporal PTT. NIR irradiation can eradicate tumor tissues and release tumor-associated antigens. It is observed that the PTT treatment of GBM-bearing mice activates natural killer cells, CD3+ T cells, CD8+ T cells, and M1 macrophages in the GBM area, increasing the therapeutic efficacy. This study demonstrates that NIR-assisted BK@AIE NPs represent a promising strategy for the improved systematic elimination of GBMs and the activation of local brain immune privilege.

A novel biodegradable injectable chitosan hydrogel for overcoming postoperative trauma and combating multiple tumors.

Wound bacterial infections and tumor recurrence are the main reasons for the poor prognosis after primary tumor resection. Here, we fabricated a novel therapeutic nanocomposite using chitosan (CS) hydrogel combined with black phosphate nanosheets (BPNSs) and in situ grown copper nanoparticles (CuNPs). The obtained hydrogel (CS@BPNSs@CuNPs), possessing a remarkable temperature-sensitive spongy-like state, offered 24.98 % blood clotting index. The released BPNSs@CuNPs could produce reactive oxygen species (ROS) to kill infected invasive bacteria (98.1 %) and inhibit local residual tumor cell regeneration (11.3 %). Moreover, by coupling the photothermal properties of BPNSs, the BPNSs@CuNPs showed 19.6 % penetration rate to cross the blood tumor barrier (BTB) for treating brain tumors. The hydrogel platform was further combined with aPD-L1-based immunotherapy to employ its synergetic therapeutic effect in the prevention of tumors. The in vivo studies showed that biodegradable hydrogel could hold a great potential as a novel strategy for improving postoperative therapy and multi-tumor treatments.

A non-enzymatic, isothermal strand displacement and amplification assay for rapid detection of SARS-CoV-2 RNA.

The current nucleic acid signal amplification methods for SARS-CoV-2 RNA detection heavily rely on the functions of biological enzymes which imposes stringent transportation and storage conditions, high cost and global supply shortages. Here, a non-enzymatic whole genome detection method based on a simple isothermal signal amplification approach is developed for rapid detection of SARS-CoV-2 RNA and potentially any types of nucleic acids regardless of their size. The assay, termed non-enzymatic isothermal strand displacement and amplification (NISDA), is able to quantify 10 RNA copies.µL-1. In 164 clinical oropharyngeal RNA samples, NISDA assay is 100 % specific, and it is 96.77% and 100% sensitive when setting up in the laboratory and hospital, respectively. The NISDA assay does not require RNA reverse-transcription step and is fast (<30 min), affordable, highly robust at room temperature (>1 month), isothermal (42 °C) and user-friendly, making it an excellent assay for broad-based testing.

Bacterial Isolation by Adsorption on Graphene Oxide from Large Volume Sample.

Graphene oxide (GO) is a well-known two-dimensional nanomaterial with broad applications in various fields. In particular, the functional groups of GO has demonstrated significance in the molecular binding interactions. GO is normally coated on a solid surface as it is difficult to handle due to its nano-scaled size. Therefore, chemical properties of surface-coated GO depend on the morphological structure of GO on the surface and the operating conditions during the coating process. Isolation of bacteria from environmental samples such as river and pond water is important for increasing the analytical sensitivity of sensor devices. The main issue in isolation of bacteria from an environmental sample is adsorption capacity per unit time. However, increasing the velocity of water sample to elevate the process rate induces high shear stress on the surface, such that the bacteria adsorption rate on the surface is reduced. In this study, we investigated the morphological and chemical properties of sonicated GO and GO-coated surface by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The sonicated GO-coated beads were successfully used for concentrating bacteria from a large-volume sample as opposed to the conventional methods. It can be concluded that, GO-coated surfaces are prospective platforms for concentrating bacteria from various samples and play a major role in reducing the concentration time.

Gold nanoparticle/MXene for multiple and sensitive detection of oncomiRs based on synergetic signal amplification.

Multiple and sensitive detection of oncomiRs for accurate cancer diagnostics is still a challenge. Here, a synergetic amplification strategy was introduced by combining a MXene-based electrochemical signal amplification and a duplex-specific nuclease (DSN)-based amplification system for rapid, attomolar and concurrent quantification of multiple microRNAs on a single platform in total plasma. Synthesized MXene-Ti3C2Tx modified with 5 nm gold nanoparticles (AuNPs) was casted on a dual screen-printed gold electrode to host vast numbers of DNA probes identically co-immobilized on dedicated electrodes. Interestingly, presence of MXene provided biofouling resistance and enhanced the electrochemical signals by almost 4 folds of magnitude, attributed to its specious surface area and remarkable charge mobility. The 5 nm AuNPs were perfectly distributed within the whole flaky architect of the MXene to give rise to the electrochemical performance of MXene and provide the thiol-Au bonding feature. This synergetic strategy reduced the DSN-based biosensors' assay time to 80 min, provided multiplexability, antifouling activity, substantial sensitivity and specificity (single mutation recognition). The limit of detection of the proposed biosensor for microRNA-21 and microRNA-141 was respectively 204 aM and 138 aM with a wide linear range from 500 aM to 50 nM. As a proof of concept, this newly-developed strategy was coupled with a 96-well adaptive sensing device to successfully profile three cancer plasma samples based on their altered oncomiR abundances.

Single Functionalized pRNA/Gold Nanoparticle for Ultrasensitive MicroRNA Detection Using Electrochemical Surface-Enhanced Raman Spectroscopy.

Controlling the selective one-to-one conjugation of RNA with nanoparticles is vital for future applications of RNA nanotechnology. Here, the monofunctionalization of a gold nanoparticle (AuNP) with a single copy of RNA is developed for ultrasensitive microRNA-155 quantification using electrochemical surface-enhanced Raman spectroscopy (EC-SERS). A single AuNP is conjugated with one copy of the packaging RNA (pRNA) three-way junction (RNA 3WJ). pRNA 3WJ containing one strand of the 3WJ is connected to a Sephadex G100 aptamer and a biotin group at each arm (SEPapt/3WJ/Bio) which is then immobilized to the Sephadex G100 resin. The resulting complex is connected to streptavidin-coated AuNP (STV/AuNP). Next, the STV/AuNP-Bio/3WJa is purified and reassembled with another 3WJ to form a single-labeled 3WJ/AuNP. Later, the monoconjugate is immobilized onto the AuNP-electrodeposited indium tin oxide coated substrate for detecting microRNA-155 based on EC-SERS. Application of an optimum potential of +0.2 V results in extraordinary amplification (≈7 times) of methylene blue (reporter) SERS signal compared to the normal SERS signal. As a result, a highly sensitive detection of 60 × 10-18 m microRNA-155 in 1 h in serum based on monoconjugated AuNP/RNA is achieved. Thus, the monofunctionalization of RNA onto nanoparticle can provide a new methodology for biosensor construction and diverse RNA nanotechnology development.

Detachable microfluidic device implemented with electrochemical aptasensor (DeMEA) for sequential analysis of cancerous exosomes.

The quantification of cancer-derived exosomes has a strong potential for minimally invasive diagnosis of cancer during its initial stage. As cancerous exosomes form a small fraction of all the exosomes present in blood, ultra-sensitive detection is a prerequisite for the development of exosome-based cancer diagnostics. Herein, a detachable microfluidic device implemented with an electrochemical aptasensor (DeMEA) is introduced for highly sensitive and in-situ quantification of cancerous exosomes. To fabricate the aptasensor, a nanocomposite was applied on the electrode surface followed by electroplating of gold nanostructures. Subsequently, an aptamer against an epithelial cell adhesion molecule is immobilized on the electrode surface to specifically detect cancer-specific exosomes. A microfluidic vortexer is then constructed and implemented in the sensing system to increase the collision between the exosomes and sensing surface using hydrodynamically generated transverse flow. The microfluidic vortexer was integrated with the aptasensor via a 3D printed magnetic housing. The detachable clamping of the two different devices provides an opportunity to subsequently harvest the exosomes for downstream analysis. The DeMEA has high sensitivity and specificity with an ultra-low limit of detection of 17 exosomes/µL over a wide dynamic range (1 × 102 to 1 × 109) exosomes/µL in a short period. As proof of the concept, the aptasensor can be separated from the 3D printed housing to harvest and analyze the exosomes by real-time polymerase chain reaction. Moreover, the DeMEA quantifies the exosomes from plasma samples of patients with breast cancer at different stages of the disease. The DeMEA provides a bright horizon for the application of microfluidic integrated biosensors for the early detection of cancerous biomarkers.

Biodegradable Poly(γ-glutamic acid)@glucose oxidase@carbon dot nanoparticles for simultaneous multimodal imaging and synergetic cancer therapy.

It is known that tumor antigens could induce obvious anti-tumor immune responses for efficient cancer immunotherapy when combined with checkpoint blockade. However, the amount of tumor antigens is often limited due to the suppressive tumor microenvironment (TME). Here, a new type of nanomaterial was developed to improve tumor treatment by the combined action of starving therapy/photodynamic therapy (PDT)/photothermal therapy (PTT) and checkpoint-blockade immunotherapy. In detail, the immunoadjuvant nanoagents (γ-PGA@GOx@Mn,Cu-CDs) were fabricated by integrating the gamma-glutamyl transferase (GGT) enzyme-induced cellular uptake polymer-poly (γ-glutamic acid) (γ-PGA), a glucose-metabolic reaction agent - glucose oxidase (GOx), Mn,Cu-doped carbon dots (CDs) as photosensitizer and self-supplied oxygenator nanodots. γ-PGA@GOx@Mn,Cu-CDs nanoparticles (NPs) showed long retention time at the tumor acidic microenvironment and could further target cancer cells. The NPs also displayed both photothermal and photodynamic effects under laser irradiation at 730 nm. Interestingly, the endogenous generation of hydrogen peroxide (H2O2) caused by the nanoreactors could significantly relieve tumor hypoxia and further enhance in vivo PDT. By synergistically combining the NPs-based starving-like therapy/PDT/PTT and check-point-blockade therapy, the treatment efficiency was significantly improved. More importantly, the systematic antitumor immune response would eliminate non-irradiated tumors as well, which is promising for metastasis inhibition.