1,720,963 research outputs found
Biocompatible Optically Transparent MEMS for Micromechanical Stimulation and Multimodal Imaging of Living Cells
Get PDFCells and tissues in our body are continuously subjected to mechanical stress. Mechanical stimuli, such as tensile and contractile forces, and shear stress, elicit cellular responses, including gene and protein alterations that determine key behaviors, including proliferation, differentiation, migration, and adhesion. Several tools and techniques have been developed to study these mechanobiological phenomena, including micro-electro-mechanical systems (MEMS). MEMS provide a platform for nano-to-microscale mechanical stimulation of biological samples and quantitative analysis of their biomechanical responses. However, current devices are limited in their capability to perform single cell micromechanical stimulations as well as correlating their structural phenotype by imaging techniques simultaneously. In this study, a biocompatible and optically transparent MEMS for single cell mechanobiological studies is reported. A silicon nitride microfabricated device is designed to perform uniaxial tensile deformation of single cells and tissue. Optical transparency and open architecture of the device allows coupling of the MEMS to structural and biophysical assays, including optical microscopy techniques and atomic force microscopy (AFM). We demonstrate the design, fabrication, testing, biocompatibility and multimodal imaging with optical and AFM techniques, providing a proof-of-concept for a multimodal MEMS. The integrated multimodal system would allow simultaneous controlled mechanical stimulation of single cells and correlate cellular response
A completely transparent MEMS for mechanical properties evaluation of a single living cell
No full textA new BioMEMS for the study of mechanosensitive ion channels
No full textA novel completely transparent bioMEMS (bio - Micro Electro Mechanical System) has been designed and produced using finite element analysis (FEA) and micro-fabrication techniques. This device has been thought to be used for testing the mechanical properties of single living cells. Our bioMEMS is versatile and can be coupled to other analysis techniques and being completely transparent can be used with either transmission or reflection microscopes. This device is based on a silicon dioxide – silicon nitride structure
A new transparent BioMEMS for uni-axial single cell stretching
No full textA novel, completely transparent bio-MEMS
(bio-Micro Electro Mechanical System) device has been
devised and manufactured using finite element analysis
(FEA) and micro-fabrication techniques. The device has
been designed to be used for testing the mechanical properties
of single living cells, it is versatile and suitable for
coupling with other analysis techniques. Furthermore,
being completely transparent, it can be used with either
transmission or reflection microscopes. The transparent
bio-MEMS is based on a silicon dioxide–silicon nitride
structure and, since the main goal is to test living cells, it is
meant to work in a liquid environment and allow for cell
stretching. Sensors for cell deformation and for platform
displacement are also present and the required sensitivity
for single cell analyses is granted. The device will moreover
allow the recording of the stress–strain curve for
single living cell
AFM Cells Morphological Analysis: Influence of Different Environmental Conditions on Fixed and Living Cell
No full textIn this paper we carried out an AFM study on cells morphology, in particular we analyzed the Influence of Different EnvironmentalConditions on Fixed and Living Ce
Metabolic and proliferative cells activity on different substrates
No full textScaffolds for tissue engineering can be either natural or synthetic materials. The latter allow control of chemical, physical and mechanical properties and also provide support and shape, however they are not of biological origin, and therefore could not promote cell adhesion. This problem does not occur in natural materials however, they have the drawback of having non-suitable mechanical properties and tend to deteriorate too fast. In this work we study the influence of different substrate on the metabolic as well as proliferative cells activity. In particular 4 substrates have been considered: (i) medical grade StageFlexer (silicone elastomer), (ii) Polydimethylsiloxane (PDMS), (iii) PDMS with a layer of carbon nanotubes (CNT’s) and (iv) PDMS with a layer of ceramic whiskers. The results of both tests (metabolic and proliferative capacity) showed that the PDMS without any surface treatment, is the worst of the tested substrates. The reason is to be found in the fact that the PDMS is highly hydrophobic and therefore cells have low adhesion to the substrate. This represents a major limitation of PDMS and its functionalization is necessary to improve cell adhesion. Cells placed on PDMS samples with CNT’s show higher metabolic activity and proliferative capacity, compared to the PDMS and PDMS treated with fibronectin. However, the best outcomes have occurred with the PDMS substrate coated with ceramic whiskers
Lithographic patterned substrate with nanotips for cell indentation
No full textWe present a method based to an in situ chemical etching strategy to synthesize glass nano tips arrays. The chemical etching can generate nanotips with controllable tip morphologies on various substrates, and the nanotips density is tunable via etching.
This general in situ chemical etching method might advance the research in the nano tips based devices for biotechnolog
Mechanical Properties of 3T3 Fibroblasts due to Fixation Assessed Using Atomic Force Microscopy
No full textIn this paper we analyzed how the Mechanical Properties of 3T3 Fibroblasts change due to Fixation procedure. This was assessed using Atomic Force Microscop
A study on the cellular structure during stress solicitation induced by BioMEMS
No full textThe investigation of single cells is a topic in continuous evolution. The complexity of the cellular matrix, the huge variety of cells, the interaction of one cell with the other are all factors that must be taken into consideration in the study of the cellular structure and mechanics. In this project, we developed different types of bioMEMS for cell's stretching, both transparent devices based on silicon nitride and non-transparent silicon based. While the use of silicon devices is limited to reflection microscopes, transparent bioMEMS can be used with transmission and reflection microscopes but can also be easily coupled with other tools such as patch clamp analyzers or atomic force microscope. This improvement will open brand new possibilities in the biological investigation field. We used these two BioMEMS to stretch a single cell in a controlled way and, as a first investigation, we focused on its morphology. We noticed that during a controlled stretch, cells react to the applied deformation. A hysteretic behavior on the ratio between area and perimeter has been highlighted
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