1,721,033 research outputs found
Hydrogel Bioactive Scaffold Fabricated with PAM2 System: Realization of Complex Shaped Scaffold with a Homogeneous Dispersion of HepG2 cells
No full textProcedimento e sistema er assemblare una forma di dosaggio orale e forma di dosaggio orale
No full textLa presente invenzione si riferisce alla produzione di medicamenti orali, ed in particolare di medicamenti costituiti da più principi attivi combinati in una singola forma di dosaggio, le cosiddette polypil
Hydrostatic pressure and shear stress affect endothelin-1 and nitric oxide release by endothelial cells in bioreactors
No full textThere is plenty of experimental evidence to show that endothelial cells are sensitive to flow, but very little attention has been paid to fluid pressure or pressure gradients which are used to drive viscous flow. In fact there are two principal physical forces exerted on the blood vessel wall by the passage of intra-luminal blood: pressure and shear. In order to analyze their independent effects, these two stresses were applied to cultured cells by means of two different bioreactors: the pressure-controlled bioreactor (PCB) and the laminar flow bioreactor (LFB), in which controlled levels of pressure and shear stress can be respectively generated. Using the bioreactor systems, endothelin-1 and nitric oxide release from human umbilical vein endothelial cells (HUVEC) were measured in varying conditions of shear stress and pressure. As result, a decrease of endothelin-1 production from the cells cultured in both bioreactors, with respect to the controls, was observed, whereas nitric oxide synthesis was up-regulated only in the presence of shear stress but not modulated by hydrostatic pressure. These results show that the two hemodynamic forces acting on blood vessels affect endothelial cell function in different ways, and that both should be considered when planning in vitro experiments in the presence of flow. Understanding the individual and synergic effects of the two forces could provide important insights into physiological and pathological processes involved in vascular remodeling and adaptation
Controlled in vitro growth of cell microtubes: towards the realisation of artificial microvessels
No full text
Preliminary experimental analysis of Reservoir Computing approach for balance assessment
Full text linkEvaluation of balance stability in elderly people is of prominent relevance in the field of health monitoring. Recently, the use of Wii Balance Board has been proposed as valid alternative to clinical balance tests, such as the widely used Berg Balance Scale (BBS) test, allowing to measure and analyze static features such as the duration or the speed of assessment of patients' center of pressure. In an innovative way, in this paper we propose to take into consideration the whole temporal information generated by the balance board, analyzing it by means of dynamical neural networks. In particular, using Recurrent Neural Networks implemented according to the Reservoir Computing paradigm, we propose to estimate the BBS score from the temporal data generated by the execution of one simple exercise on the balance board. Preliminary experimental assessments of the proposed approach on a real-world dataset show promising results
A High-throughput bioreactor system for simulating physiological environments
No full textThe optimization of in vitro cell culture for tissue engineering, pharmacological, or metabolic studies requires a large number of experiments to be performed under varying conditions. In this paper, we describe a high-throughput bioreactor system that allows the conduction of parallel experiments in a simulated in vivo-like environment. Our bioreactors consist of tissue-, organ-, or system-specific culture chambers and a mixing device controlled by an embedded system that regulates the insertion of gas in the culture medium in order to control pH and pressure. Each culture chamber and mixing device possesses an autonomous control system that is able to ensure an optimal environment for cells. A computer communicates with the embedded system to acquire data and set up experimental variables. With this apparatus, we can perform a high-throughput experiment controlling several bioreactors working in parallel. In this paper, we discuss the architecture and design of the system, and the results of some experiments which simulate physiological and pathological conditions are presented
Design and Validation of an Open-Hardware Print-Head for Bioprinting Application
Full text linkIn the last decades drop-on-demand inkjet technology played an increasing role in industrial and medical applications. This is due to the ability to deposit a small amount of material in precisely defined position. In the field of Biofabrication, inkjet printers are used to build 2D and 3D scaffolds and gels with biological molecules, including living cells. Several works, including seminal papers on inkjet bioprinting, were carried out with modified office printers. These printers have fixed structural characteristics and operating size, especially on the print-head, limiting the range of materials that can be dispensed. The aim of the present work is the design and fabrication of an open-source piezoelectric inkjet print-head, optimized for the bioprinting field. This low-cost, reproducible, reliable, versatile and biocompatible device will enable various research laboratories to work with a shared device; the open source allowing for parts to be modified to suit specific needs. The design was carried out by Finite Element (FE) modelling of the piezoelectric, mechanical, fluid dynamics and their coupling. The design was optimized for shear rate, which we minimized in order to be able to print cells. The mechanical frame of the printer was designed and built using a low-cost 3D printer. The nozzle plate was fabricated from a polycarbonate disc coated with biocompatible silicone, to increase the hydrophobicity of the outer surface of the disc, preventing ink adhesion on the edge of the nozzle; the refilling system, and the electronic control were also part of the project and will be freely available to download. The FE models were validated with ad-hoc experiments, printing water, gelatin solution, and cell culture media, by modulating the wave power in amplitude, frequency and duty cycle. The tests showed a large working window both respect to viscosity and to surface tension. Finally Human Skin Fibroblasts (ATCC-CRL- 2522, Teddington UK), suspended in culture media, were printed. Cell viability, assessed by CellTiter-Blue and LIVE / DEAD tests, resulted comparable with the control, demonstrating the validity of the first open source piezoelectric inkjet print-head for biofabrication
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