Design and fabrication of flexible DNA polymer cocoons to encapsulate live cells.

The capability to encapsulate designated live cells into a biologically and mechanically tunable polymer layer is in high demand. Here, an approach to weave functional DNA polymer cocoons has been proposed as an encapsulation method. By developing in situ DNA-oriented polymerization (isDOP), we demonstrate a localized, programmable, and biocompatible encapsulation approach to graft DNA polymers onto live cells.

Host-Guest Chemistry in Layer-by-Layer Assemblies Containing Calix[n]arenes and Cucurbit[n]urils: A Review.

This review provides an overview of the synthesis of layer-by-layer (LbL) assemblies containing calix[]arene (CA[]) and cucurbit[]uril (CB[]) and their applications. LbL assemblies, such as thin films and microcapsules, containing selective binding sites have attracted considerable attention because of their potential use in separation and purification, sensors for ions and molecules, and controlled release. CA[]-containing LbL films have been prepared using sulfonated CA[] and cationic polymers to construct chemical sensors and molecular containers.

Voltammetric Response of Alizarin Red S-Confined Film-Coated Electrodes to Diol and Polyol Compounds: Use of Phenylboronic Acid-Modified Poly(ethyleneimine) as Film Component.

Alizarin red S (ARS) was confined in layer-by-layer (LbL) films composed of phenylboronic acid-modified poly(ethyleneimine) (PBA-PEI) and carboxymethylcellulose (CMC) to study the voltammetric response to diol and polyol compounds. The LbL film-coated gold (Au) electrode and quartz slide were immersed in an ARS solution to uptake ARS into the film. UV-visible absorption spectra of ARS-confined LbL film suggested that ARS formed boronate ester (ARS-PBS) in the film.

Photosensitive Layer-by-Layer Assemblies Containing Azobenzene Groups: Synthesis and Biomedical Applications.

This review provides an overview of the syntheses of photosensitive layer-by-layer (LbL) films and microcapsules modified with azobenzene derivatives and their biomedical applications. Photosensitive LbL films and microcapsules can be prepared by alternate deposition of azobenzene-bearing polymers and counter polymers on the surface of flat substrates and microparticles, respectively. Azobenzene residues in the films and microcapsules exhibit trans-to-cis photoisomerization under UV light, which causes changes in the physical or chemical properties of the LbL assemblies.

Lactate-induced decomposition of layer-by-layer films composed of phenylboronic acid-modified poly(allylamine) and poly(vinyl alcohol) under extracellular tumor conditions.

Multilayer films that decompose in the presence of lactate were prepared by depositing phenylboronic acid-modified poly(allylamine) (PBA-PAH) and poly(vinyl alcohol) (PVA) on a lactate oxidase (LOx) layer. The layers adhered through boronate ester bonds. The resulting LOx(PBA-AH/PVA) film was stable in pH 7.

Ultrasensitive Quantitation of Plasma Membrane Proteins via isRTA.

Quantitation of plasma membrane proteins (PMPs) is fundamental and frequently performed daily in the lab. However, challenged by the inherent/interacting heterostructures and complex surroundings of the PMPs in lipid membrane, quantitative techniques for PMP often require complex treatments (e.g.

Alizarin Red S-Confined Layer-By-Layer Films as Redox-Active Coatings on Electrodes for the Voltammetric Determination of L-Dopa.

The preparation of redox-active coatings is a key step in fabricating electrochemical biosensors. To this goal, a variety of coating materials have been used in combination with redox-active compounds. In this study, alizarin red S (ARS) was confined in layer-by-layer (LbL) films composed of poly(ethyleneimine) (PEI) and carboxymethylcellulose (CMC) to study the redox properties.

Recent Progress in Nanomaterial-Based Electrochemical Biosensors for Cancer Biomarkers: A Review.

This article reviews recent progress in the development of nanomaterial-based electrochemical biosensors for cancer biomarkers. Because of their high electrical conductivity, high affinity to biomolecules, and high surface area-to-weight ratios, nanomaterials, including metal nanoparticles, carbon nanotubes, and graphene, have been used for fabricating electrochemical biosensors. Electrodes are often coated with nanomaterials to increase the effective surface area of the electrodes and immobilize a large number of biomolecules such as enzymes and antibodies.

Phenylboronic Acid-Functionalized Layer-by-Layer Assemblies for Biomedical Applications.

Recent progress in the development of phenylboronic acid (PBA)-functionalized layer-by-layer (LbL) assemblies and their biomedical applications was reviewed. Stimuli-sensitive LbL films and microcapsules that exhibit permeability changes or decompose in response to sugars and hydrogen peroxide (H₂O₂) have been developed using PBA-bearing polymers. The responses of PBA-modified LbL assemblies arise from the competitive binding of sugars to PBA in the films or oxidative decomposition of PBA by H₂O₂.

Sugar-sensitive dendrimer films as a sacrificial layer for the preparation of freestanding multilayer films.

Multilayer thin films composed of poly(vinyl alcohol) (PVA) and phenylboronic acid-bearing poly(amidoamine) dendrimer (PBA-PAMAM) were used as a sacrificial layer for constructing freestanding polyelectrolyte films consisting of poly(styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). Freestanding (PSS/PAH) films were successfully released from substrate by exposing composite (PVA/PBA-PAMAM)/(PSS/PAH) films (n=5 and 10) to sorbitol solutions under mild conditions at pH7.0-9.

Recent Progress in Electrochemical Biosensors for Glycoproteins.

This review provides an overview of recent progress in the development of electrochemical biosensors for glycoproteins. Electrochemical glycoprotein sensors are constructed by combining metal and carbon electrodes with glycoprotein-selective binding elements including antibodies, lectin, phenylboronic acid and molecularly imprinted polymers. A recent trend in the preparation of glycoprotein sensors is the successful use of nanomaterials such as graphene, carbon nanotube, and metal nanoparticles.

Recent progress in electrochemical biosensors based on phenylboronic acid and derivatives.

This review provides an overview of recent progress made in the development of electrochemical biosensors based on phenylboronic acid (PBA) and its derivatives. PBAs are known to selectively bind 1,2- and 1,3-diols to form negatively charged boronate esters in neutral aqueous media and have been used to construct electrochemical glucose sensors because of this selective binding. PBA-modified metal and carbon electrodes have been widely studied as voltammetric and potentiometric glucose sensors.

Preparation of Layer-by-Layer Films Composed of Polysaccharides and Poly(Amidoamine) Dendrimer Bearing Phenylboronic Acid and Their pH- and Sugar-Dependent Stability.

Layer-by-layer films composed of polysaccharides and poly(amidoamine) dendrimer bearing phenylboronic acid (PBA-PAMAM) were prepared to study the deposition behavior of the films and their stability in buffer solutions and in sugar solutions. Alginic acid (AGA) and carboxymethylcellulose (CMC) were employed as counter-polymers in constructing LbL films. AGA/PBA-PAMAM films were successfully prepared at pH 6.

Enzymatically Regulated Peptide Pairing and Catalysis for the Bioanalysis of Extracellular Prometastatic Activities of Functionally Linked Enzymes.

Diseases such as cancer arise from systematical reconfiguration of interactions of exceedingly large numbers of proteins in cell signaling. The study of such complicated molecular mechanisms requires multiplexed detection of the inter-connected activities of several proteins in a disease-associated context. However, the existing methods are generally not well-equipped for this kind of application.

pH- and sugar-sensitive multilayer films composed of phenylboronic acid (PBA)-modified poly(allylamine hydrochloride) (PBA-PAH) and poly(vinyl alcohol) (PVA): A significant effect of PBA content on the film stability.

Multilayer thin films composed of phenylboronic acid (PBA)-modified poly(allylamine hydrochloride) (PAH), PBA-PAH, with different PBA contents were prepared to study the effect of PBA content on the stability of the films. An alternate deposition of PBA-PAH and poly(vinyl alcohol) (PVA) on the surface of a quartz slide afforded multilayer films through forming boronate ester bonds between PBA-PAH and PVA. The 10-layered (PBA-PAH/PVA)10 films constructed using PBA-PAHs containing 16% and 26% PBA residues were stable in aqueous solutions over the range of pH 4.

Recent Progress in Lectin-Based Biosensors.

This article reviews recent progress in the development of lectin-based biosensors used for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins. Lectin proteins have been widely used for the construction of optical and electrochemical biosensors by exploiting the specific binding affinity to carbohydrates. Among lectin proteins, concanavalin A (Con A) is most frequently used for this purpose as glucose- and mannose-selective lectin.

Mitochonic Acid 5 Binds Mitochondria and Ameliorates Renal Tubular and Cardiac Myocyte Damage.

Mitochondrial dysfunction causes increased oxidative stress and depletion of ATP, which are involved in the etiology of a variety of renal diseases, such as CKD, AKI, and steroid-resistant nephrotic syndrome. Antioxidant therapies are being investigated, but clinical outcomes have yet to be determined. Recently, we reported that a newly synthesized indole derivative, mitochonic acid 5 (MA-5), increases cellular ATP level and survival of fibroblasts from patients with mitochondrial disease.

Glucose-induced decomposition of layer-by-layer films composed of phenylboronic acid-bearing poly(allylamine) and poly(vinyl alcohol) under physiological conditions.

Multilayer thin films prepared via layer-by-layer (LbL) deposition of phenylboronic acid-bearing poly(allylamine hydrochloride) (PBA-PAH) and poly(vinyl alcohol) (PVA) were combined with glucose oxidase (GOx) to develop LbL films that can be decomposed in response to glucose. LbL deposition of PBA-PAH and PVA on a GOx-modified quartz slide afforded GOx/(PBA-PAH/PVA) films, in which PBA-PAH and PVA layers were connected to each other through boronate ester bonds, while GOx was immobilized electrostatically. The GOx/(PBA-PAH/PVA) films were stable in glucose-free solutions under physiological conditions.

Mitochonic Acid 5 (MA-5), a Derivative of the Plant Hormone Indole-3-Acetic Acid, Improves Survival of Fibroblasts from Patients with Mitochondrial Diseases.

Mitochondria are key organelles implicated in a variety of processes related to energy and free radical generation, the regulation of apoptosis, and various signaling pathways. Mitochondrial dysfunction increases cellular oxidative stress and depletes ATP in a variety of inherited mitochondrial diseases and also in many other metabolic and neurodegenerative diseases. Mitochondrial diseases are characterized by the dysfunction of the mitochondrial respiratory chain, caused by mutations in the genes encoded by either nuclear DNA or mitochondrial DNA.

Recent Progress in Electrochemical HbA1c Sensors: A Review.

This article reviews recent progress made in the development of electrochemical glycated hemoglobin (HbA1c) sensors for the diagnosis and management of diabetes mellitus. Electrochemical HbA1c sensors are divided into two categories based on the detection protocol of the sensors. The first type of sensor directly detects HbA1c by binding HbA1c on the surface of an electrode through bio-affinity of antibody and boronic acids, followed by an appropriate mode of signal transduction.

Electrochemical biosensors based on ferroceneboronic Acid and its derivatives: a review.

We review recent progress in the development of electrochemical biosensors based on ferroceneboronic acid (FcBA) and ferrocene (Fc)-modified boronic acids. These compounds can be used to construct electrochemical biosensors because they consist of a binding site (i.e.

Multilayer films composed of phenylboronic acid-modified dendrimers sensitive to glucose under physiological conditions.

Layer-by-layer (LbL) multilayer films were prepared using phenylboronic acid-modified poly(amidoamine) dendrimers and poly(vinyl alcohol) (PVA) in order to investigate the glucose sensitivity of the films. We used dendrimer derivatives modified with 3-carboxyphenylboronic acid (3CPBA-D) and 3-carboxy-5-nitrophenylboronic acid (3C5NPBA-D) to evaluate the effect of electron-withdrawing nitro groups on glucose sensitivity. PVA/3CPBA-D and PVA/3C5NPBA-D films were prepared on the surface of a quartz slide from PVA and 3CPBA-D or 3C5NPBA-D solutions at pH 7.

Loading and release of fluorescent dye from layer-by-layer film-coated magnetic particles in response to hydrogen peroxide.

Polymer-coated magnetic particles (MPs) were prepared to study the binding of fluorescence dye on the surface and its H2O2-induced release. For this goal, multilayer films were prepared by layer-by-layer deposition of shikimic acid-appended poly(allylamine hydrochloride) (SA-PAH) and poly(styrenesulfonate) (PSS) on the surface of MPs. 3-(Dansylamino)phenylboronic acid (DPBA) was loaded on the MPs through boronate ester bonding between SA-PAH and DPBA.

H2O2-induced decomposition of layer-by-layer films consisting of phenylboronic acid-bearing poly(allylamine) and poly(vinyl alcohol).

Layer-by-layer (LbL) films were prepared by an alternate deposition of phenylboronic acid-bearing poly(allylamine hydrochloride) (PBA-PAH) and poly(vinyl alcohol) (PVA) on the surface of a quartz slide to develop thin films that can be decomposed in response to hydrogen peroxide (H2O2). The PBA-PAH/PVA films decomposed in the presence of H2O2; the degree and kinetics of decomposition depend on the concentration of H2O2 and on the pH of the solution. For example, the film decomposition completely occurred in 30 min in 1.

Poly(lactic acid) microparticles coated with insulin-containing layer-by-layer films and their pH-dependent insulin release.

Poly(lactic acid) (PLA) microparticles were coated with layer-by-layer (LbL) films containing insulin and the pH-dependent release of insulin was studied. The LbL films were prepared on the surface of PLA microparticles by the alternate deposition of insulin and poly(allylamine hydrochloride) (PAH) through the electrostatic attraction between insulin and PAH. The insulin loading on the PLA microparticles depended on the film thickness, which corresponded to the number of insulin layers, and on the pH of the solution used to deposit insulin.