The combination of chemotherapy and photodynamic therapy (PDT) has promising potential in the synergistic treatment of cancer. However, chemotherapy and photodynamic synergistic therapy are impeded by uncontrolled chemotherapeutics release behavior, targeting deficiencies, and hypoxia-associated poor PDT efficacy in solid tumors. Here, a platinum nanozyme (PtNP) loaded reactive oxygen species (ROS)-responsive prodrug nanoparticle (CPT-TK-HPPH/Pt NP) is created to overcome these limitations. The ROS-responsive prodrug consists of a thioketal bond linked with camptothecin (CPT) and photosensitizer-2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH). The PtNP in CPT-TK-HPPH/Pt NP can efficiently catalyze the decomposition of hydrogen peroxide (H2O2) into oxygen to relieve hypoxia. The production of oxygen can satisfy the consumption of HPPH under 660 nm laser irradiation to attain the on-demand release of CPT and ensure enhanced photodynamic therapy. As a tumor diagnosis agent, the results of photoacoustic imaging and fluorescence imaging for CPT-TK-HPPH/Pt NP exhibit desirable long circulation and enhanced in vivo targeting. CPT-TK-HPPH/Pt NPs effectively inhibit tumor proliferation and growth in vitro and in vivo. CPT-TK-HPPH/Pt NP, with its excellent ROS-responsive drug release behavior and enhanced PDT efficiency can serve as a new cancer theranostic agent, and will further promote the research of chemophotodynamic synergistic cancer therapy.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.202001853

Polymeric Nanoparticles with ROS‐Responsive Prodrug and Platinum Nanozyme for Enhanced Chemophotodynamic Therapy of Colon Cancer

Strategies for developing sensitive and specific nanoparticle-based lateral flow assays as point-of-care diagnostic device

Anti-fouling and thermosensitive ion-imprinted nanocomposite membranes based on grapheme oxide and silicon dioxide for selectively separating europium ions.

Current signal amplification strategies in aptamer-based electrochemical biosensor: A review

Infectious diseases claim millions of lives each year. Robust and accurate diagnostics are essential tools for identifying those who are at risk and in need of treatment in low-resource settings. Inorganic complexes and metal-based nanomaterials continue to drive the development of diagnostic platforms and strategies that enable infectious disease detection in low-resource settings. In this review, we highlight works from the past 20 years in which inorganic chemistry and nanotechnology were implemented in each of the core components that make up a diagnostic test. First, we present how inorganic biomarkers and their properties are leveraged for infectious disease detection. In the following section, we detail metal-based technologies that have been employed for sample preparation and biomarker isolation from sample matrices. We then describe how inorganic- and nanomaterial-based probes have been utilized in point-of-care diagnostics for signal generation. The following section discusses instrumentation for signal readout in resource-limited settings. Next, we highlight the detection of nucleic acids at the point of care as an emerging application of inorganic chemistry. Lastly, we consider the challenges that remain for translation of the aforementioned diagnostic platforms to low-resource settings.

Inorganic Complexes and Metal-Based Nanomaterials for Infectious Disease Diagnostics.

The development of a sensitive and rapid diagnostic test is needed for early detection of avian influenza (AI) H7 subtype. In this study, novel monoclonal antibodies (mAbs) against influenza A H7N9 recombinant hemagglutinin (rHA)1 were developed and applied to a Europium nanoparticle–based rapid fluorescent immunochromatographic strip test (FICT) to improve the sensitivity of the rapid diagnostic system. Two antibodies (2F4 and 6D7) exhibited H7 subtype specificity in a dot-FICT assay by optimization of the conjugate and the pH of the lysis buffer. The subtype specificity was confirmed by an immunofluorescence assay and Western blot analysis. The limit of detection of the FICT employing novel mAbs 31 ng/mL for H7N9 rHA1 and 40 hemagglutination units/mL for H7 subtype virus. Sensitivity was improved 25-fold using Europium as confirmed by comparison of colloidal gold-based rapid diagnostic kit using the 2F4 and 6D7 mAbs.

/pdf/improvement-of-a-rapid-diagnostic-application-of-monoclonal-2en7j7gop6.pdf

Improvement of a rapid diagnostic application of monoclonal antibodies against avian influenza H7 subtype virus using Europium nanoparticles.

Currently, the point of care testing (POCT) is not fully developed for subtype-specific avian influenza virus detection. In this study, an H5N1 hemaglutinin 1 (HA1) epitope (P0: KPNDAINF) and three modified peptides (P1: KPNTAINF, P2: KPNGAINF, P3: KPNDAINDAINF) were evaluated as POCT elements for rapid detection of avian influenza virus. Based on modeling predictions by Autodock Vina, binding affinity varied depending on alteration of one amino acid in these peptides. The binding energy of P2 indicated its potential for a strong interaction with HA. Fluorescence-linked immunosorbent assay experimentally demonstrated the interaction between these peptides and virus. The four peptides interacted with HA1 of H5N3 with different binding affinities with P2 showing the strongest binding affinity. When P0 and P2 peptides were used in rapid fluorescent immunochromatographic test (FICT) as detection elements, the inter-assay coefficients of variation (CV) indicated that P2-linked FICT was more acceptable than the P0-linked FICT in the presence of human specimens. Antibody pair-linked FICT was influenced by clinical samples more than the P2-linked FICT assay, which showed a 4-fold improvement in the detection limit of H5N3 and maintained H5 subtype-specificity. Compared to the rapid diagnostic test (RDT) which is not specific for influenza subtypes, P2-linked FICT could increase virus detection. In conclusion, results of this study suggest that HA epitope-derived peptides can be used as alternatives to antibodies for a rapid fluorescent diagnostic assay to detect avian influenza virus.

Rapid Detection of Avian Influenza Virus by Fluorescent Diagnostic Assay using an Epitope-Derived Peptide.

Alternative antibody (aptamer)-based biosensors are attracting increasing attention owing to advantages such as simplicity and low cost, which are beneficial for point-of-care diagnosis, particularly where resources are limited. In this study based on in silico modeling predictions made with Autodock Vina, the binding affinity of an optimized novel peptide (Pf_P1: KITTTDEEVEGIFD) was altered compared to that of the original epitope peptide (P1: KITDEEVEGIFDC). The binding energy of Pf_P1 implies that it has stronger interactions with Plasmodium falciparum lactate dehydrogenase (LDH) than with human LDH. Fluorescence-linked immunosorbent assay (FLISA) demonstrated significant interactions (P < 0.05) between the Pf_P1 peptide and P. falciparum LDH at 35.7 nmol. A peptide- and antibody-linked sandwich FLISA was able to detect at least 100 infected red blood cells (RBC)/μL significantly (P < 0.001). The clinical diagnostic performance of peptide- and antibody-linked sandwich FLISA was evaluated using blood samples from patients infected by P. falciparum with parasitemia values of 151 to 128,636. All positive samples exhibited higher fluorescence than normal samples did. In conclusion, in silico modeling was used to efficiently design a Plasmodium LDH epitope-derived peptide aptamer to function as an alternative to antibodies in immunoassays.

A Novel Peptide Aptamer to Detect Plasmodium falciparum Lactate Dehydrogenase.

Plasmodium lactate dehydrogenase (pLDH) is a strong target antigen for the determination of infection with Plasmodium species specifically. However, a more effective antibody is needed because of the low sensitivity of the current antibody in many immunological diagnostic assays. In this study, recombinant Plasmodium vivax LDH (PvLDH) was experimentally constructed and expressed as a native antigen to develop an effective P. vivax-specific monoclonal antibody (mAb). Two mAbs (2CF5 and 1G10) were tested using ELISA and immunofluorescence assays (IFA), as both demonstrated reactivity against pLDH antigen. Of the 2 antibodies, 2CF5 was not able to detect P. falciparum, suggesting that it might possess P. vivax-specificity. The detection limit for a pair of 2 mAbs-linked sandwich ELISA was 31.3 ng/ml of the recombinant antigen. The P. vivax-specific performance of mAbs-linked ELISA was confirmed by in vitro-cultured P. falciparum and P. vivax-infected patient blood samples. In conclusion, the 2 new antibodies possessed the potential to detect P. vivax and will be useful in immunoassay.

/pdf/development-of-monoclonal-antibodies-for-diagnosis-of-2qlq9njho1.pdf

Nguyen Thi Phuong Linh

Papers

Improvement of a rapid diagnostic application of monoclonal antibodies against avian influenza H7 subtype virus using Europium nanoparticles.

Rapid Detection of Avian Influenza Virus by Fluorescent Diagnostic Assay using an Epitope-Derived Peptide.

A Novel Peptide Aptamer to Detect Plasmodium falciparum Lactate Dehydrogenase.

Development of Monoclonal Antibodies for Diagnosis of Plasmodium vivax.