DoE Analysis of Approaches for Hydrogel Microbeads' Preparation by Millifluidic Methods

Hydrogel microbeads hold great promise for immune-protective cell transplants and in vitro studies. Millifluidic generation of hydrogel microbeads is a highly efficient and reproducible approach enabling a mass production. This paper illustrates the preparation and characterization of highly controlled and reproducible microbeads made by different types of hydrogel using millifluidic approaches. The optimization of the process was made by a design of experiments (DoE) approach. The microbeads' large-scale production can be potentially used for single cells or clusters encapsulation

Tunable and Reversible Gelatin-Based Bonding for Microfluidic Cell Culture

The development of novel bonding techniques could enable new applications and uses of plastics in microfluidic cell culture, complementing the omnipresent polydimethylsiloxane (PDMS). In this respect, the present paper describes a reversible gelatin-based method (named GEL-D) for bonding microfluidic chip parts, constituted of different materials. The herein introduced method enables the bonding of the most of the commonly used materials in microfluidics such as PMMA, PDMS, glass and NOA. Notably, the fabricated chips resist to pressure up to 0.7 MPa, to organic solvent exposure and temperature up to 70 °C. To show the versatility of the described method, microchips with different sizes, materials, and geometries were bonded, including microchannel down to 200 µm (width x depth) and round microstructures. The bonded chips are suitable to microfluidic cell culture procedures, including formation of microtissues, cells viability analysis and confocal microscopy. Therefore, the room-temperature bonding method appear to be highly efficient for cell culture on plastic chips, where in situ analysis of the seeded cells is required after microchip de-bonding

From square to circular polymeric microchannels by spin coating technology: a low cost platform for endothelial cell culture

Square microchannels are easy to fabricate by means of micromachining or lithographic techniques. However, in vitro vascular microcapillaries-as well as plug production and microparticle alignment-require mainly circular microchannels that can be used also in applications based on open microchannels. Nowadays, a simple, low cost, and versatile method to fabricate circular microchannels is still missing. Here, we report on a fast, inexpensive, flexible and reproducible method to fabricate circular microchannels by coupling spin coating with micromilled square microchannels. The proposed method is based on the balance between the displacement of liquid PDMS induced by centrifugal forces and the surface tension that tends to keep the liquid accumulated especially in the corners, which become therefore rounded. To show the versatility of the described experimental study we prepared a variety of rounded microchannels, including branched and PMMA-PDMS hybrid configuration microchannels. Finally, an endothelial cell layer was formed by culturing brain endothelial bEnd.3 cells inside the proposed circular microchannels. Results demonstrated a more successful adhesion, growth, and homogeneous distribution of the cells along the circular microchannel than those observed in the square microchannel used as a control

Fabrication of a modular hybrid chip to mimic endothelial-lined microvessels in flow conditions

In vitro microvessel models exploiting microfluidic channels have been developed to replicate cardiovascular flow conditions and to more closely mimic the blood vessels by traditionally using plasma or solvent evaporation bonding methods. The drawback of these methods is represented by an irreversible sealing which prevents internal accessibility as well as the reuse of the device. This paper presents a novel, simple, and low cost procedure to fabricate a modular and reusable chip with endotheliazed microvessels in a hybrid configuration based on poly( methyl methacrylate) and polydimethylsiloxane presenting a temporary magnetic bonding. In details, small magnets are embedded in the two poly( methyl methacrylate) substrates each of them carrying a thin polydimethylsiloxane layer which provides enhanced sealing during flow conditions as compared to conventional procedures and makes the microchannels circular as preferred in cell culture. Finally, an endothelial cell layer is formed by culturing brain endothelial bEnd. 3 cells inside the proposed microchannels and characterized upon microchannel aperture, demonstrating the preservation of the cell layer

Evaluation of a Set of Indicators Devoted to the Service of Health Education: the Case of the Biotechnology Centre of the AORN Hospital "A. Cardarelli" in Naples

The work begins with an introduction about two concepts: Quality and Indicators. The most important aim of this work is to evaluate the training service offered by the "Centro di Biotecnologie", analyzing each phase of the process, to realize an appropriate indicators set that can be used to assess the quality level reached in the service delivery. To analyze the training service, it is also important to evaluate the Customer Satisfaction, to realize a needs hierarchy through a statistical analysis realized with the "Analytic Hierarchy Process"

Acute disseminated cryptococcosis in lupus nephritis: report of a fatal case

We report a clinical case of systemic lupus erythematosus with fatal infection from Cryptococcus neoformans. The patient had a rapidly progressive renal failure due to lupus nephritis. She was severely immunodepressed especially by the disease, and secondarily by immunosuppressive therapy. She had more probabilities to be exposed to fungal infections because she lived in a rural area. This report enhances an interesting discussion about the utility of employing antifungal drugs in immunodepressed patients submitted to empirical antibiotic treatment because of fever of unknown aetiology

Shuttle-Mediated Nanoparticle Transport Across an In Vitro Brain Endothelium Under Flow Conditions

The blood brain barrier (BBB) represents a challenge in the development of new nano-delivery systems able to reach the central nervous system (CNS). In order to test the efficacy of these nanocarriers, it is fundamental to use in vitro models that resemble the in vivo cell culture conditions. Here, we demonstrate for the first time the ability of a membranotropic peptide, namely gH625, to transport a cargo-acting as a shuttle-across the BBB layer under flow conditions that mimic the blood flow rate. To this aim, a BBB microfluidic device was designed based on a transparent polyester porous membrane sandwiched between a top and a bottom overlying channel made of poly(methyl methacrylate) (PMMA). Our data clearly indicate that this microfluidic system allows the growth of brain endothelial bEnd. 3 cells and the formation of a confluent layer at 7 days of culture that hinders the passage of nanoparticles compared to porous membrane alone. The device was validated at a 5 mu L/min working flow rate, where the capability of the model to remain intact after nanoparticle passage was shown. Very interestingly, the decoration with the gH625 peptide enhances the adhesion of nanoparticles to the endothelial layer and the BBB crossing in flow conditions, thus confirming the efficacy of the gH625 as a delivery platform to the brain. (C) 2016 Wiley Periodicals, Inc

Easy Surface Functionalization and Bioconjugation of Peptides as Capture Agents of a Microfluidic Biosensing Platform for Multiplex Assay in Serum

The development of assays for protein biomarkers in complex matrices is a demanding task that still needs implementation of new approaches. Antibodies as capture agents have been largely used in bioassays but their low stability, low-efficiency production, and cross-reactivity in multiplex approaches impairs their larger applications. Instead, synthetic peptides, even with higher stability and easily adapted amino acid sequences, still remain largely unexplored in this field. Here, we provide a proof-of-concept of a microfluidic device for direct detection of biomarker overexpression. The multichannel microfluidic polydimethylsiloxane (PDMS) device was first derivatized with PAA (poly(acrylic acid)) solution. CRP-1, VEGF-114, and φG6 peptides were preliminarily tested to respectively bind the biomarkers, C-reactive protein (CRP), vascular endothelial growth factor (VEGF), and tumor necrosis factor-alpha (TNF-α). Each PDMS microchannel was then respectively bioconjugated with a specific peptide (CRP-1, VEGF-114, or φG6) to specifically capture CRP, VEGF, and TNF-α. With such microdevices, a fluorescence bioassay has been set up with sensitivity in the nanomolar range, both in buffered solution and in human serum. The proposed multiplex assay worked with a low amount of sample (25 μL) and detected biomarker overexpression (above nM concentration), representing a noninvasive and inexpensive screening platform