Biomaterials

Non-linear microscopy of smooth muscle cells in artificial extracellular matrices made of cellulose

by Nihal Engin Vrana

Authors: Christian Brackmann, Jan-Olof Dahlberg, Nihal Engin Vrana, Caitriona Lally , Paul Gatenholm, Annika Enejder,
Published in Journal of Biophotonics

Non-linear microscopy has been used to characterize bovine smooth muscle cells and their proliferation, migration, and... more Non-linear microscopy has been used to characterize bovine smooth muscle cells and their proliferation, migration, and differentiation in hydrogel cellulose scaffolds, toward the development of fully functional blood vessel implants. The extracellular matrix (ECM) composed of cellulose and endogenous collagen fibers was imaged using Second Harmonic Generation (SHG) microscopy and the cell morphology by Coherent Anti-Stokes Raman Scattering (CARS) microscopy. Images prove that cells adhere on the cellulose scaffold without additional surface modification and that both contractile and proliferating phenotypes are developed. This work shows that non-linear microscopy contributes with unique insights in cell interactions with (artificial) ECM components and has the potential to become an established characterization method in tissue engineering.

Mechanical and Microstructural Properties of Sheep Hydroxyapatite (SHA)-Niobium Oxide Composites

by Nermin Demirkol

Absorption and Fluorescence Properties of Oligothiophene Biomarkers from Long-Range-Corrected Time-Dependent Density Functional Theory

by Bryan Wong

Physical Chemistry Chemical Physics, 11, 4498 (2009)

Technology mapping of the scientific research in biomaterials: a trends study of years 2000-2002.

by Elias Olivares-Benitez

Co-authored with Marisela Rodriguez-Salvador and Dieter Scharnweber

Creative Technical Intelligence in Biomaterials: a technology mapping proposal.

by Elias Olivares-Benitez

Bio-hybrid tactile sensor and experimental set-up for investigating and mimicking the human sense of touch

by David Cheneler

Cheneler, D., Buselli, E, Oddo, C. M., Kaklamani, G., Beccai, L, Carrozza, M. C., Grover, L., Anthony, C., Ward, M. C. L. and Adams, M., (2012), Bio-hybrid tactile sensor and experimental set-up for investigating and mimicking the human sense of touch, Proceedings of HRI2012, Boston, USA, 3rd March 2012

In this paper, we describe the design and fabrication of a bio-hybrid tactile sensor and experimental platform. The... more In this paper, we describe the design and fabrication of a bio-hybrid tactile sensor and experimental platform. The system uses tissue engineered alginate encapsulated fibroblasts and a conductivity sensor as a transduction system to monitor applied normal and tangential loads in a manner comparable to mechanotransduction in the human haptic system in nonglabrous skin. The tissue is integrated into a microfluidic system interfaced with a nanoporous membrane capable of sustaining the viability of the cells for extended times. The efficacy of the bio-hybrid tactile sensor is validated using a 2 DoF Cartesian manipulator, capable of indenting and sliding textured stimuli over the device. Also, the platform includes a two-cell Peltier-based temperature controlled control module. This allows the evaluation of the effect of temperature variation on the bio-hybrid sensor response, and to decouple the effect of temperature from mechanical stimulation.

Biomimetic isotropic nanostructures for structural coloration

by Vinod Kumar Saranathan

Colour-producing β-keratin nanofibres in blue penguin (Eudyptula minor) feathers

by Vinod Kumar Saranathan

Evolutionary Photonics: Structure, function, development and evolution of organismal structural color

by Vinod Kumar Saranathan

Structure, function, and self-assembly of single network gyroid (I4132) photonic crystals in butterfly wing scales

by Vinod Kumar Saranathan

Self-assembly of amorphous biophotonic nanostructures by phase separation

by Vinod Kumar Saranathan

Proposed Design of a low-cost mhealth System

by Rajat Kumar

Rajat Kumar and Arvind Rehalia ,Published in International Journal of Modelling and Optimization, IACSIT Press, Singapore.

This paper proposes a model for low cost design of mhealth solutions. The model presented here is based on RF... more This paper proposes a model for low cost design of mhealth solutions. The model presented here is based on RF transmitter and receiver, microcontroller and cellular network integration and uses F-BUS protocol for transmitting and receiving data using a NOKIA 3310 handset. The proposed design aims at eliminating the need of smart-phone dependent costly mhealth solutions. Also, the current paper presents the essential comparative data and statistics to support the concerned proposed design.

Cite: Rajat Kumar and Arvind Rehalia, "Proposed Design of a Low Cost mHealth System," International Journal of Modeling and Optimization vol. 2, no. 1, pp. 15-18, 2012.

Rajat Kumar is with the Bharati Vidyapeeth's College of Engineering, Guru Gobind Singh Indraprastha University , New Delhi , India (e-mail: rajatk489@gmail.com).

Arvind Rehalia is with the Bharati Vidyapeeth's College of Engineering, Guru Gobind Singh Indraprastha University, New Delhi, India (e-mail: rehaliaarvind@gmail.com).

The use of a dual PEDOT and RGD-functionalized alginate hydrogel coating to provide sustained drug delivery and improved cochlear implant function

by Jennifer Chikar

Electron transfer in dextran probed by longitudinal field muon spin relaxation

by Mark Telling

Electron-transfer processes play a crucial role in bio-nanobattery design, the electron transfer rate through the... more Electron-transfer processes play a crucial role in bio-nanobattery design, the electron transfer rate through the organic material being a key parameter in determining the resistance, maximum current, power density, discharge rate and duty cycle of the cell. The labelled electron method using positive muons allows such transfer processes in macromolecules, such as polymers and proteins, to be probed on a microscopic level. Here we present the results of an experiment using the labelled electron method with longitudinal field muon spin relaxation (LF-μSR) to investigate electron-transfer processes in dextran. The data are well described using the Risch–Kehr model and the results suggest intra-chain diffusion is the dominant transport process in this system between 15 and 250 K. Intra-chain diffusion rates of 1013 s−1 have been determined.

Tunable Properties of Self-Assembled Polyurethane Using Two-Dimensional Nanoparticles: Potential Nano-Biohybrid

by Abhinay Mishra

published in Macromolecules, 2010

Unexpected Strength and Toughness in Chitosan-Fibroin Laminates Inspired by Insect Cuticle

by Javier G. Fernandez

Co-authored with D.E. Ingber, Published in 'Advanced Materials'

A material inspired by natural insect cuticle and composed of chitosan and fibroin is created. The material exhibits... more A material inspired by natural insect cuticle and composed of chitosan and fibroin is created. The material exhibits the strength of an aluminum alloy at half its weight, while being clear, biocompatible, biodegradable, and micromoldable. The bioinspired laminate exhibits strength and toughness that are ten times greater than the unstructured component blend and twice that of its strongest constituent.

Directional alignment of MG63 cells on polymer surfaces containing point microstructures

by Javier G. Fernandez

Co-authored with Christopher A. Mills and Josep Samitier, Published in "Small"

MG63 cells cultured on regular arrays of point microstructures (posts and holes) are shown to preferentially align at... more MG63 cells cultured on regular arrays of point microstructures (posts and holes) are shown to preferentially align at certain angles to the pattern of the structures, at 0 degrees, 30 degrees, and 45 degrees in particular. The effect is found to be more pronounced for post rather than hole structures (although no significant difference is found for the angles the cells make to the holes or posts) and is thought to be due to the fact that the cells use the posts as anchorage points to hold themselves to the surface. It is also shown that cells preferentially align with the structures depending on the dimensions of the structures and the distance between neighboring structures. This is important when designing structured surfaces for cell-surface interaction studies for materials to be used in, for example, drug delivery or tissue engineering.

Simultaneous biochemical and topographical patterning on curved surfaces using biocompatible sacrificial molds

by Javier G. Fernandez

Published in "Journal of Biomedical Materials Research"

A method for the simultaneous (bio)chemical and topographical patterning of enclosed structures in poly(dimethyl... more A method for the simultaneous (bio)chemical and topographical patterning of enclosed structures in poly(dimethyl siloxane) (PDMS) is presented. The simultaneous chemical and topography transference uses a water-soluble chitosan sacrificial mold to impart a predefined pattern with micrometric accuracy to a PDMS replica. The method is compared to conventional soft-lithography techniques on planar surfaces. Its functionality is demonstrated by the transference of streptavidin directly to the surface of the three-dimensional PDMS structures as well as indirectly using streptavidin-loaded latex nanoparticles. The streptavidin immobilized on the PDMS is tested for bioactivity by coupling with fluorescently labeled biotin. This proves that the streptavidin is immobilized on the PDMS surface, not in the bulk of the polymer, and is therefore accessible for use as signaling/binding element in micro and bioengineering. The use of a biocompatible polymer and processes enables the technique to be used for the chemical patterning of tissue constructions.

Mesenchymal Stem Cell Fate is Regulated by the Composition and Mechanical Properties of Collagen-Glycosaminoglycan Scaffolds

by Matthew Haugh

Published in the Journal of the Mechanical Behavior of Biomedical Materials

In stem cell biology, focus has recently turned to the influence of the intrinsic properties of the extracellular... more In stem cell biology, focus has recently turned to the influence of the intrinsic properties of the extracellular matrix (ECM), such as structural, composition and elasticity, on stem cell differentiation. Utilising collagen-glycosaminoglycan (CG) scaffolds as an analogue of the ECM, this study set out to determine the effect of scaffold stiffness and composition on naive mesenchymal stem cell (MSC) differentiation in the absence of differentiation supplements. Dehydrothermal (DHT) and 1-ethyl-3-3-dimethyl aminopropyl carbodiimide (EDAC) crosslinking treatments were used to produce three homogenous CG scaffolds with the same composition but different stiffness values: 0.5, 1 and 1.5 kPa. In addition, the effect of scaffold composition on MSC differentiation was investigated by utilising two glycosaminoglycan (GAG) types: chondroitin sulphate (CS) and hyaluronic acid (HyA). Results demonstrated that scaffolds with the lowest stiffness (0.5 kPa) facilitated a significant up-regulation in SOX9 expression indicating that MSCs are directed towards a chondrogenic lineage in more compliant scaffolds. In contrast, the greatest level of RUNX2 expression was found in the stiffest scaffolds (1.5 kPa) indicating that MSCs are directed towards an osteogenic lineage in stiffer scaffolds. Furthermore, results demonstrated that the level of up-regulation of SOX9 was higher within the CHyA scaffolds in comparison to the CCS scaffolds indicating that hyaluronic acid further influences chondrogenic differentiation. In contrast, enhanced RUNX2 expression was observed in the CCS scaffolds in comparison to the CHyA scaffolds suggesting an osteogenic influence of chondroitin sulphate on MSC differentiation. In summary, this study demonstrates that, even in the absence of differentiation supplements, scaffold stiffness can direct the fate of MSCs, an effect that is further enhanced by the GAG type used within the CG scaffolds. These results have significant implications for the therapeutic uses of stem cells and enhance our understanding of the physical effects of the in vivo microenvironment on stem cell behaviour.

Surface-engineered substrates for improved human pluripotent stem cell culture under fully defined conditions

by Krishanu Saha

The current gold standard for the culture of human pluripotent stem cells requires the use of a feeder layer of cells.... more The current gold standard for the culture of human pluripotent stem cells requires the use of a feeder layer of cells. Here, we develop a spatially defined culture system based on UV/ozone radiation modification of typical cell culture plastics to define a favorable surface environment for human pluripotent stem cell culture. Chemical and geometrical optimization of the surfaces enables control of early cell aggregation from fully dissociated cells, as predicted from a numerical model of cell migration, and results in significant increases in cell growth of undifferentiated cells. These chemically defined xeno-free substrates generate more than three times the number of cells than feeder-containing substrates per surface area. Further, reprogramming and typical gene-targeting protocols can be readily performed on these engineered surfaces. These substrates provide an attractive cell culture platform for the production of clinically relevant factor-free reprogrammed cells from patient tissue samples and facilitate the definition of standardized scale-up friendly methods for disease modeling and cell therapeutic applications.