Biocompatible Size-Defined Dendrimer-Albumin Binding Protein Hybrid Materials as a Versatile Platform for Biomedical Applications

Nanoparticles in the diagnosis and treatment of vascular aging and related diseases

Aging-induced alternations of vasculature structures, phenotypes, and functions are key in the occurrence and development of vascular aging-related diseases. Multiple molecular and cellular events, such as oxidative stress, mitochondrial dysfunction, vascular inflammation, cellular senescence, and epigenetic alterations are highly associated with vascular aging physiopathology. Advances in nanoparticles and nanotechnology, which can realize sensitive diagnostic modalities, efficient medical treatment, and better prognosis as well as less adverse effects on non-target tissues, provide an amazing window in the field of vascular aging and related diseases. Throughout this review, we presented current knowledge on classification of nanoparticles and the relationship between vascular aging and related diseases. Importantly, we comprehensively summarized the potential of nanoparticles-based diagnostic and therapeutic techniques in vascular aging and related diseases, including cardiovascular diseases, cerebrovascular diseases, as well as chronic kidney diseases, and discussed the advantages and limitations of their clinical applications.

Cell immunocapture microfluidic chip based on high-affinity recombinant protein binders

Cell immunocapture microfluidic devices represent a rapidly developing field with many potential applications in medical diagnostics. The core of such approach lies in the cell binding to antibody coated surfaces through their surface receptors. Here we show, that the small recombinant protein binders (PBs) can be used for this purpose as well, with the advantage of their constructional flexibility, possibility of fusion with range of tags and cheap mass production. For this purpose, two different PBs derived from Albumin Binding Domain (ABDwt) of streptococcal protein G, so called REX and ARS ligands with proved high affinity and selectivity to the human interleukin-23 (IL-23R) and IL-17 receptor A were used. Four PBs variants recognizing two different epitopes on two different receptors and two PBs variants binding to the same epitope on one receptor but having different peptide spacer with Avitag sequence necessary for their immobilization on sensor surface were tested for cell-capture efficiency. The glass microfluidic Y-system with planar immunocapture channel working in so-called stop-flow dynamic regime was designed. Up to 60-74% immunocapture efficiency of model THP-1 cells on REX/ARS surfaces and practically no cell binding on control ABDwt surfaces was achieved. Moreover, the specific immunocapture of THP-1 cells from mixture with IL-17RA negative DU-145 cells was demonstrated. We discuss the role of the epitope, affinity and immobilization spacer of PBs as well as the influence of stop-flow dynamic regime on the effectivity of THP-1 cell immunocapture. Results can be further exploited in design of microfluidic devices for rare cells immunocapture.

Biotinylated Phosphorus Dendrimers as Control Line in Nucleic Acid Lateral Flow Tests

Lateral flow assays (LFA) are an affordable, easy-to-use, qualitative rapid test for clinical diagnosis in nonlaboratory environments and low-resource facilities. The control line of these tests is very important to provide a valid result, confirming that the platform operates correctly. A clear, nondiffused line is desirable. The number of colored nanoparticles that reach the control line in a positive test can be very small, and they should all be trapped efficiently by the molecules adsorbed there. In this work, we proposed the use of robust biotinylated dendrimers of two different generations as signal amplifiers in control lines of LFA, able to react with streptavidin-modified gold nanoparticles. Besides the synthesis and characterization, the analytical performance as control lines will be studied, and their response will be compared with other commercially available biotinylated molecules. Finally, the utility of the dendrimer implemented in a NALF (Nucleic Acid Lateral Flow) strip was also demonstrated for detection of the amplicons obtained by double-tagging PCR (polymerase chain reaction) for the detection of E. coli as a model of foodborne pathogen.

Dendrimers: Amazing Platforms for Bioactive Molecule Delivery Systems

Today, dendrimers are the main nanoparticle applied to drug delivery systems. The physicochemical characteristics of dendrimers and their versatility structural modification make them attractive to applied as a platform to bioactive molecules transport. Nanoformulations based on dendrimers enhance low solubility drugs, arrival to the target tissue, drugs bioavailability, and controlled release. This review describes the latter approaches on the transport of bioactive molecules based on dendrimers. The review focus is on the last therapeutic strategies addressed by dendrimers conjugated with bioactive molecules. A brief review of the latest studies in therapies against cancer and cardiovascular diseases, as well as future projections in the area, are addressed.

Carbosilane dendrimers with phosphonium terminal groups are low toxic non-viral transfection vectors for siRNA cell delivery

Non-viral gene delivery vectors studied in the gene therapy applications are often designed with the cationic nitrogen containing groups necessary for binding and cell release of nucleic acids. Disadvantage is a relatively high toxicity which restricts the in vivo use of such nanoparticles. Here we show, that the 3rd generation carbosilane dendrimers possessing (trimethyl)phosphonium (PMe₃) groups on their periphery were able to effectively deliver the functional siRNA into the cells (B14, Cricetulus griseus), release it into the cytosol and finally to achieve up to 40% gene silencing of targeted gene (glyceraldehyde-3-phosphate dehydrogenase (GAPDH)) with the comparable or, in some cases, even better effectivity as their ammonium counterparts. Moreover, such cationic dendrimers show relatively low in vivo toxicity as compared to their ammonium analogues when analyzed by standard fish embryo test (FET) on Danio rerio in vivo model, with LD₅₀ = 6.26 µM after 48 h of incubation. This is more than 10-fold improvement as compared to published values for various other types of cationic dendrimers. We discuss the potential of further increase of the transfection efficiency, endosomal escape and decrease of toxicity of such non-viral vectors, based on the systematic screening of different types of substituents on central phosphonium atom.

Phosphonium carbosilane dendrimers for biomedical applications – synthesis, characterization and cytotoxicity evaluation

Phosphonium carbosilane dendrimers could represent an alternative to ammonium ones in gene therapy applications with high potential of mitochondrial targeting.

High-throughput screening of triplex DNA binders from complicated samples by 96-well pate format in conjunction with peak area-fading UHPLC-Orbitrap MS

Screening triplex DNA binders from complicated samples in a high-throughput fashion with good reproducibility without the requirement of an extra releasing step.

Coil-like Enzymatic Biohybrid Structures Fabricated by Rational Design: Controlling Size and Enzyme Activity over Sequential Nanoparticle Bioconjugation and Filtration Steps

Well-defined enzymatic biohybrid structures (BHS) composed of avidin, biotinylated poly(propyleneimine) glycodendrimers, and biotinylated horseradish peroxidase were fabricated by a sequential polyassociation reaction to adopt directed enzyme prodrug therapy to protein-glycopolymer BHS for potential biomedical applications. To tailor and gain fundamental insight into pivotal properties such as size and molar mass of these BHS, the dependence on the fabrication sequence was probed and thoroughly investigated by several complementary methods (e.g., UV/vis, DLS, cryoTEM, AF4-LS). Subsequent purification by hollow fiber filtration allowed us to obtain highly pure and well-defined BHS. Overall, by rational design and control of preparation parameters, e.g., fabrication sequence, ligand-receptor stoichiometry, and degree of biotinylation, well-defined BHS with stable and even strongly enhanced enzymatic activities can be achieved. Open coil-like structures of BHS with few branches are available by the sequential bioconjugation approach between synthetic and biological macromolecules possessing similar size dimensions.