Towards Aptamer-Targeted Drug Delivery to Brain Tumors: The Synthesis of Ramified Conjugates of an EGFR-Specific Aptamer with MMAE on a Cathepsin B-Cleavable Linker.

Targeted delivery of chemotherapeutic agents is a well-established approach to cancer therapy. Antibody-drug conjugates (ADCs) typically carry toxic payloads attached to a tumor-associated antigen-targeting IgG antibody via an enzyme-cleavable linker that releases the drug inside the cell. Aptamers are a promising alternative to antibodies in terms of antigen targeting; however, their polynucleotide nature and smaller size result in a completely different PK/PD profile compared to an IgG.

Detection of α-Galactosidase A Reaction in Samples Extracted from Dried Blood Spots Using Ion-Sensitive Field Effect Transistors.

Fabry disease is a lysosomal storage disorder caused by a significant decrease in the activity or absence of the enzyme α-galactosidase A. The diagnostics of Fabry disease during newborn screening are reasonable, due to the availability of enzyme replacement therapy. This paper presents an electrochemical method using complementary metal-oxide semiconductor (CMOS)-compatible ion-sensitive field effect transistors (ISFETs) with hafnium oxide-sensitive surfaces for the detection of α-galactosidase A activity in dried blood spot extracts.

A Portable Readout System for Biomarker Detection with Aptamer-Modified CMOS ISFET Array.

Biosensors based on ion-sensitive field effect transistors (ISFETs) combined with aptamers offer a promising and convenient solution for point-of-care testing applications due to the ability for fast and label-free detection of a wide range of biomarkers. Mobile and easy-to-use readout devices for the ISFET aptasensors would contribute to further development of the field. In this paper, the development of a portable PC-controlled device for detecting aptamer-target interactions using ISFETs is described.

Biological Activity of Artificial Plant Peptides Corresponding to the Translational Products of Small ORFs in Primary miRNAs and Other Long "Non-Coding" RNAs.

Generally, lncPEPs (peptides encoded by long non-coding RNAs) have been identified in many plant species of several families and in some animal species. Importantly, molecular mechanisms of the miPEPs (peptides encoded by primary microRNAs, pri-miRNAs) are often poorly understood in different flowering plants. Requirement for the additional studies in these directions is highlighted by alternative findings concerning positive regulation of pri-miRNA/miRNA expression by synthetic miPEPs in plants.

Targeting GD2-Positive Tumor Cells by Pegylated scFv Fragment-Drug Conjugates Carrying Maytansinoids DM1 and DM4.

Oligomerization of antibody fragments via modification with polyethylene glycol (pegylation) may alter their function and properties, leading to a multivalent interaction of the resulting constructs with the target antigen. In a recent study, we generated pegylated monomers and multimers of scFv fragments of GD2-specific antibodies using maleimide-thiol chemistry. Multimerization enhanced the antigen-binding properties and demonstrated a more efficient tumor uptake in a syngeneic GD2-positive mouse cancer model compared to monomeric antibody fragments, thereby providing a rationale for improving the therapeutic characteristics of GD2-specific antibody fragments.

Recombinant Fusion Protein Containing Plant Nigellothionin Regulates the Growth of Food-Spoiling Fungus ().

This study aimed to obtain a recombinant chimeric protein named trx-NsW2 via theheterologous expression of the multifunctional antimicrobial peptide nigellothionin from black cumin ( L.) seeds in the system. The protein was purified using a combination of Ni-NTA affinity chromatography and reversed-phase HPLC.

Off-Stoichiometry Thiol-Ene Polymers: Inclusion of Anchor Groups Using Allylsilanes.

The use of polymers in silicon chips is of great importance for the development of microelectronic and biomedical industries. In this study, new silane-containing polymers, called OSTE-AS polymers, were developed based on off-stoichiometry thiol-ene polymers. These polymers can bond to silicon wafers without pretreatment of the surface by an adhesive.

Aminooxy Click Modification of a Periodate-Oxidized Immunoglobulin G: A General Approach to Antibody-Drug Conjugates with Dye-Mediated Expeditious Stoichiometry Control.

A universal approach to the construction of antibody-drug conjugates (ADCs) has been developed. It relies on periodate oxidation of naturally present glycans of immunoglobulin G, followed by oxime ligation and, optionally, copper(I)-catalyzed alkyne-azide cycloaddition for conjugation with a toxic payload. The introduction of highly absorbing cyanine dyes into the linker allows for facile determination of the drug-antibody ratio.

Regulatory miPEP Open Reading Frames Contained in the Primary Transcripts of microRNAs.

This review aims to consider retrospectively the available data on the coding properties of pri-microRNAs and the regulatory functions of their open reading frames (ORFs) and the encoded peptides (miPEPs). Studies identifying miPEPs and analyzing the fine molecular mechanisms of their functional activities are reviewed together with a brief description of the methods to identify pri-miRNA ORFs and the encoded protein products. Generally, miPEPs have been identified in many plant species of several families and in a few animal species.

Minibody-Based and scFv-Based Antibody Fragment-Drug Conjugates Selectively Eliminate GD2-Positive Tumor Cells.

Ganglioside GD2 is a well-established target expressed on multiple solid tumors, many of which are characterized by low treatment efficiency. Antibody-drug conjugates (ADCs) have demonstrated marked success in a number of solid tumors, and GD2-directed drug conjugates may also hold strong therapeutic potential. In a recent study, we showed that ADCs based on the approved antibody dinutuximab and the drugs monomethyl auristatin E (MMAE) or F (MMAF) manifested potent and selective cytotoxicity in a panel of tumor cell lines and strongly inhibited solid tumor growth in GD2-positive mouse cancer models.

Branched Linkers for Site-Specific Fluorescent Labeling of Antibodies.

Fluorescent antibodies have proved to be an invaluable tool for molecular biology and diagnostics. They are routinely produced by modification of lysine residues, which leads to high heterogeneity. As such, their affinity may be compromised if the antigen-binding site is affected, the probability of which increases along with the degree of labeling.

Rational Design of Plant Hairpin-like Peptide EcAMP1: Structural-Functional Correlations to Reveal Antibacterial and Antifungal Activity.

Plant antimicrobial peptides from the α-hairpinins family (hairpin-like peptides) are known to possess a wide range of biological activities. However, less is known about the structural determinants of their antimicrobial activity. Here, we suggest that spatial structure as well as surface charge and hydrophobicity level contribute to the antimicrobial properties of α-hairpinin EcAMP1 from barnyard grass () seeds.

Off-Stoichiometry Thiol-Enes Polymers Containing Silane Groups for Advanced Packaging Technologies.

New modified off-stoichiometry thiol-enes polymers, called OSTE-MS polymers, were developed by introducing mercaptosilane into the polymer mixture. This modification made it possible to introduce silane groups into the polymer frame, due to which the polymer gained the ability to bond with silicon wafers without modification of the wafer surface by any adhesive. The optimal composition for creating 3D polymer structures on a chip was selected, which consists of a volume ratio of 6:6:1 of allyl monomer, mercapto monomer, and mercaptosilane, respectively.

7,8-Dihydro-8-oxo-1,N6-ethenoadenine: an exclusively Hoogsteen-paired thymine mimic in DNA that induces A→T transversions in Escherichia coli.

This work investigated the structural and biological properties of DNA containing 7,8-dihydro-8-oxo-1,N6-ethenoadenine (oxo-ϵA), a non-natural synthetic base that combines structural features of two naturally occurring DNA lesions (7,8-dihydro-8-oxoadenine and 1,N6-ethenoadenine). UV-, CD-, NMR spectroscopies and molecular modeling of DNA duplexes revealed that oxo-ϵA adopts the non-canonical syn conformation (χ = 65º) and fits very well among surrounding residues without inducing major distortions in local helical architecture. The adduct remarkably mimics the natural base thymine.

Sensitive Immunofluorescent Detection of the PRAME Antigen Using a Practical Antibody Conjugation Approach.

Bioconjugation of antibodies with various payloads has diverse applications across various fields, including drug delivery and targeted imaging techniques. Fluorescent immunoconjugates provide a promising tool for cancer diagnostics due to their high brightness, specificity, stability and target affinity. Fluorescent antibodies are widely used in flow cytometry for fast and sensitive identification and collection of cells expressing the target surface antigen.

Probing GFP Chromophore Analogs as Anti-HIV Agents Targeting LTR-III G-Quadruplex.

Green fluorescent protein (GFP) chromophore and its congeners draw significant attention mostly for bioimaging purposes. In this work we probed these compounds as antiviral agents. We have chosen LTR-III DNA G4, the major G-quadruplex (G4) present in the long terminal repeat (LTR) promoter region of the human immunodeficiency virus-1 (HIV-1), as the target for primary screening and designing antiviral drug candidates.

Molecular Beacon DNA Probes with Fluorescein Bifluorophore.

Unlabelled: An azido-derivative of a fluorescein bifluorophore was obtained and used for the synthesis of "molecular beacon"-type oligonucleotide fluorogenic probes for RT-PCR. Eight probe variants were synthesized based on an optimized sequence: with one or two quencher residues at the 3'-end, with a single or bifluorophore fluorescein label attached to 5'-end using modifying phosphoramidites (short linker) or "click reaction" (long linker). Comparison of probes in RT-PCR showed that probes with a doubled quencher (single fluorescein on a short linker) and doubled dye on a short linker (single dye) are somewhat superior in sensitivity to a standard probe (single quencher, single dye on a short linker) by the value of ΔC = 1-2.

Activity of Chemically Synthesized Peptide Encoded by the miR156A Precursor and Conserved in the Brassicaceae Family Plants.

It was recently found that the primary transcripts of some microRNA genes (pri-miRNAs) are able to express peptides with 12 to 40 residues in length. These peptides, called miPEPs, participate in the transcriptional regulation of their own pri-miRNAs. In our previous studies, we used bioinformatic approach for comparative analysis of pri-miRNA sequences in plant genomes to identify a new group of miPEPs (miPEP-156a peptides) encoded by pri-miR156a in several dozen species of the Brassicaceae family.

Rolling circle amplification with fluorescently labeled dUTP-balancing the yield and degree of labeling.

Detection methods based on rolling circle amplification (RCA) have been applied to a large number of targets in molecular biology. The key feature of RCA-based methods as well as other nucleic acid amplification methods is their exceptional sensitivity, which allows the detection of molecules at low concentrations, achieved by signal amplification due to nucleic acid magnification and subsequent detection. Variations on the method, such as immuno-RCA, extend the range of potential targets that can be detected.

Extracellular heat shock proteins and cancer: New perspectives.

Heat shock proteins (HSPs) are a large family of molecular chaperones aberrantly expressed in cancer. The expression of HSPs in tumor cells has been shown to be implicated in the regulation of apoptosis, immune responses, angiogenesis and metastasis. Given that extracellular vesicles (EVs) can serve as potential source for the discovery of clinically useful biomarkers and therapeutic targets, it is of particular interest to study proteomic profiling of HSPs in EVs derived from various biological fluids of cancer patients.

Diversity of Harpin-Like Defense Peptides from Barnyard Grass (Echinochloa crusgalli L.) Seeds.

The results of the study of the structure and function of harpin-like peptides (alpha-harpinins) of the EcAMP group from the barnyard grass (E. crusgalli) seeds and the possibility of their involvement in the innate immunity to biotic stresses are presented.

Integration of a field effect transistor-based aptasensor under a hydrophobic membrane for bioelectronic nose applications.

A new bioelectronic nose based on a field effect transistor coupled with an aptamer as the sensing element was developed. The gas-to-liquid extraction interface required for appropriate aptamer function was integrated into standard CMOS technology. It was developed with the use of a sacrificial aluminium etching technique combined with surface modifications by silanes for wettability control.

Development of the covalent antibody-DNA conjugates technology for detection of IgE and IgM antibodies by immuno-PCR.

Immuno-PCR (iPCR) is one of the methods used for the detection of a wide range of analytes and features the high sensitivity of the polymerase chain reaction (PCR) method. iPCR uses antibodies coupled to DNA, followed by the amplification of the attached DNA using RT-PCR. Two major types of antibody-DNA conjugates are currently used, which are obtained as a result of non-covalent (biotin-streptavidin) or covalent interactions.

Primary Structure Analysis of Antifungal Peptides from Cultivated and Wild Cereals.

Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in the range and level of their antimicrobial activity. We performed a primary structure analysis of some antimicrobial peptides from wild and cultivated cereals to find out the features that are associated with the much higher antimicrobial resistance characteristic of wild plants.

A Novel Fluorescent GFP Chromophore Analog-Based Dye for Quantitative PCR.

This is the first report describing the possibility of using a green fluorescent protein chromophore synthetic analog, P-HOBDI-BF, as a fluorescent dye for a linear hydrolysis probe used in qPCR. The study was carried out on a system for detection of the plant pathogenic fungus Fusarium avenaceum using a plasmid containing translation elongation factor 1α fragment as a template. To estimate fluorogenic properties of P-HOBDI-BF, 6-FAM- and BDP-FL-labeled probes were used.