Label-free SERS for rapid identification of interleukin 6 based on intrinsic SERS fingerprint of antibody‑gold nanoparticles conjugate.

A label-free surface-enhanced Raman scattering (SERS) was designed for sensitive detection of interleukin-6 (IL-6). The sensing element composed of anti-IL-6 antibodies adsorbed on the surface of spherical gold nanoparticles (AuNPs) as SERS-active surface. The principle of detection was probing antibody conformational changes using its intrinsic SERS fingerprint after binding to IL-6.

Enhanced Adipogenic Differentiation of Human Dental Pulp Stem Cells in Enzymatically Decellularized Adipose Tissue Solid Foams.

Engineered 3D human adipose tissue models and the development of physiological human 3D in vitro models to test new therapeutic compounds and advance in the study of pathophysiological mechanisms of disease is still technically challenging and expensive. To reduce costs and develop new technologies to study human adipogenesis and stem cell differentiation in a controlled in vitro system, here we report the design, characterization, and validation of extracellular matrix (ECM)-based materials of decellularized human adipose tissue (hDAT) or bovine collagen-I (bCOL-I) for 3D adipogenic stem cell culture. We aimed at recapitulating the dynamics, composition, and structure of the native ECM to optimize the adipogenic differentiation of human mesenchymal stem cells.

Design of a photoelectrochemical lab-on-a-chip immunosensor based on enzymatic production of quantum dots .

In this work we report the development and validation of a photoelectrochemical immunosensor on the basis of alkaline phosphatase (ALP)-linked immunoassay for the detection of human serum albumin as a model analyte. In this biosensor, oriented immobilization of capture antibodies on aminated polystyrene was achieved physical adsorption. After the interaction with the analyte, ALP immobilised on the surface through the sandwich immunoassay catalyses the hydrolysis of sodium thiophosphate (TP) to hydrogen sulphide (HS) which in the presence of cadmium ions yields CdS quantum dots (QDs).

Osteogenic differentiation of human dental pulp stem cells in decellularised adipose tissue solid foams.

3D cell culture systems based on biological scaffold materials obtainable from both animal and human tissues constitute very interesting tools for cell therapy and personalised medicine applications. The white adipose tissue (AT) extracellular matrix (ECM) is a very promising biomaterial for tissue engineering due to its easy accessibility, malleability and proven biological activity. In the present study, human dental pulp stem cells (hDPSCs) were combined in vitro with ECM scaffolds from porcine and human decellularised adipose tissues (pDAT, hDAT) processed as 3D solid foams, to investigate their effects on the osteogenic differentiation capacity and bone matrix production of hDPSCs, compared to single-protein-based 3D solid foams of collagen type I and conventional 2D tissue-culture-treated polystyrene plates.

/Macrophage Biointerface on Human and Porcine Decellularized Adipose Matrices.

Macrophages, cells effective in sensing, internalizing and killing , are intertwined with the extracellular matrix (ECM) through different signals, which include the release of specific cytokines. Due to the importance of these interactions, the employment of in vitro models mimicking a fungal infection scenario is essential to evaluate the ECM effects on the macrophage response. In this work, we have analyzed the effects of human and porcine decellularized adipose matrices (DAMs), obtained by either enzymatic or organic solvent treatment, on the macrophage/ interface.

Effects of Human and Porcine Adipose Extracellular Matrices Decellularized by Enzymatic or Chemical Methods on Macrophage Polarization and Immunocompetence.

The decellularized extracellular matrix (ECM) obtained from human and porcine adipose tissue (AT) is currently used to prepare regenerative medicine bio-scaffolds. However, the influence of these natural biomaterials on host immune response is not yet deeply understood. Since macrophages play a key role in the inflammation/healing processes due to their high functional plasticity between M1 and M2 phenotypes, the evaluation of their response to decellularized ECM is mandatory.

Development of portable CdS QDs screen-printed carbon electrode platform for electrochemiluminescence measurements and bioanalytical applications.

In this work, a portable and disposable screen-printed electrode-based platform for CdS QDs electrochemiluminescence (ECL) detection is presented. CdS QDs were synthesized in aqueous media and placed on top of carbon electrodes by drop casting. The CdS QDs spherical assemblies consisted of nanoparticles about 4 nm diameters and served as ECL sensitizers to enzymatic assays.

Antibody-Directed Synthesis of Catalytic Nanoclusters for Bioanalytical Assays.

Synthesis of atomic nanoclusters (NCs) using proteins as a scaffold has attracted great attention. Usually, the synthetic conditions for the synthesis of NCs stabilized with proteins require extreme pH values or temperature. These harsh reaction conditions cause the denaturation of the proteins and end up in the loss of their biological functions.

Modification of chlorosulfonated polystyrene substrates for bioanalytical applications.

In this work the modification of polystyrene micro-well plates and their use as bioanalytical platform is described. A wet-chemical procedure was applied for the chlorosulfonation of these polystyrene substrates (PS) resulting in well-controlled and reactive surfaces. This method enabled the production of transparent and stable substrates under ambient conditions.

CdS quantum dots generated in-situ for fluorometric determination of thrombin activity.

A method is presented for sensitive determination of thrombin activity. It is based on (a) the interaction between fibrinogen after activation with thrombin, and (b) an enzymatic amplification step consisting of in-situ growth of CdS quantum dots (QDs). Fibrinogen is immobilized on the surface of the wells of a microplate and then incubated with a mixture of biotinylated fibrinogen and thrombin.

Biosensing strategies based on enzymatic reactions and nanoparticles.

Enzymes are pivotal elements in bioanalysis due to their specificity and extremely high catalytic activity. The sensitivity of bioanalytical assays depends mainly on the capacity of an observer to detect the product(s) of a biocatalytic reaction. Both natural and artificial compounds have been traditionally used to evaluate enzymatic activities.

Specific bioanalytical optical and photoelectrochemical assays for detection of methanol in alcoholic beverages.

Methanol is a poison which is frequently discovered in alcoholic beverages. Innovative methods to detect methanol in alcoholic beverages are being constantly developed. We report for the first time a new strategy for the detection of methanol using fluorescence spectroscopy and photoelectrochemical (PEC) analysis.

Biointegration of corneal macroporous membranes based on poly(ethyl acrylate) copolymers in an experimental animal model.

Currently available keratoprosthesis models (nonbiological corneal substitutes) have a less than 75% graft survival rate at 2 years. We aimed at developing a model for keratoprosthesis based on the use of poly(ethyl acrylate) (PEA)-based copolymers, extracellular matrix-protein coating and colonization with adipose-derived mesenchymal stem cells. Human adipose tissue derived mesenchymal stem cells (h-ADASC) colonization efficiency of seven PEA-based copolymers in combination with four extracellular matrix coatings were evaluated in vitro.

Fibronectin fixation on poly(ethyl acrylate)-based copolymers.

The aim of this paper is to quantify the adhered fibronectin (FN; by adsorption and/or grafting) and the exposure of its cell adhesive motifs (RGD and FNIII7-10) on poly(ethyl acrylate) (PEA) copolymers whose chemical composition has been designed to increase wettability and to introduce acid functional groups. FN was adsorbed to PEA, poly(ethyl acrylate-co-hydroxyethyl acrylate), poly(ethyl acrylate-co-acrylic acid), and poly(ethyl acrylate-co-methacrylic acid) copolymers, and covalently cross-linked to poly(ethyl acrylate-co-acrylic acid) and poly(ethyl acrylate-co-methacrylic acid) copolymers. Amount of adhered FN and exhibition of RGD and FNIII7- 10 fragments involved in cell adhesion were quantified with enzyme-linked immunosorbent assay tests.

Chlorosulfonation of polystyrene substrates for bioanalytical assays: distribution of activated groups at the surface.

In this work the activation of transparent PS substrates by chlorosulfonation is described and their distribution in the subsurface region is analyzed. For this purpose XPS, FTIR-ATR and colorimetry have been used. It is shown that the electrophilic aromatic substitution of polystyrene in pure chlorosulfonic acid is extremely quick with complete surface coverage by chlorosulfonic groups achieved after only a 10 minute reaction time at -10 °C.

Effects of bacterial adhesion with respect to the type of material, structure and design of intraocular lenses.

The properties of the biomaterials used to constitute lenses are important factors choosing a lens for human implantation because these can influence in posterior clinical evolutions of patients. In this study, different characteristics of intraocular lenses such as chemical composition, surface roughness and lens design have been investigated in terms of their influence into a pathological environment. Eight commercial lenses were tested by optical profiling, Infrared spectra with Fourier transformation (FTIR), water-material contact angle and scanning electron microscope (SEM) to know their chemical composition and structural characteristics.