Crosslinker length dictates step-growth hydrogel network formation dynamics and allows rapid on-chip photoencapsulation

AbstractVarious biofunctional hydrogel materials can be fabricated in aqueous media through the self-assembly of peptide derivatives, forming supramolecular nanostructures and their three-dimensional networks. In this study, we describe the self-assembly of new Fmoc-dipeptides comprising α-methyl-L-phenylalanine. We found that the position and number of methyl groups introduced onto the α carbons of the Fmoc-dipeptides by α-methyl-L-phenylalanine have a marked influence on the morphology of the supramolecular nanostructure as well as the hydrogel (network) formation ability.

Download Full-text

Spatially resolved non-invasive chemical stimulation for modulation of signalling in reconstructed neuronal networks

Journal of The Royal Society Interface ◽

10.1098/rsif.2005.0099 ◽

2005 ◽

Vol 3 (7) ◽

pp. 333-343 ◽

Cited By ~ 6

Author(s):

Yulia Mourzina ◽

Alfred Steffen ◽

Dmitri Kaliaguine ◽

Bernhard Wolfrum ◽

Petra Schulte ◽

...

Keyword(s):

Cortical Neurons ◽

Network Architecture ◽

Neuronal Networks ◽

Network Formation ◽

Microcontact Printing ◽

Chemical Stimulation ◽

Functional Coupling ◽

Non Invasive ◽

On Chip

Functional coupling of reconstructed neuronal networks with microelectronic circuits has potential for the development of bioelectronic devices, pharmacological assays and medical engineering. Modulation of the signal processing properties of on-chip reconstructed neuronal networks is an important aspect in such applications. It may be achieved by controlling the biochemical environment, preferably with cellular resolution. In this work, we attempt to design cell–cell and cell–medium interactions in confined geometries with the aim to manipulate non-invasively the activity pattern of an individual neuron in neuronal networks for long-term modulation. Therefore, we have developed a biohybrid system in which neuronal networks are reconstructed on microstructured silicon chips and interfaced to a microfluidic system. A high degree of geometrical control over the network architecture and alignment of the network with the substrate features has been achieved by means of aligned microcontact printing. Localized non-invasive on-chip chemical stimulation of micropatterned rat cortical neurons within a network has been demonstrated with an excitatory neurotransmitter glutamate. Our system will be useful for the investigation of the influence of localized chemical gradients on network formation and long-term modulation.

Download Full-text

Understanding of hydrogel network formation and its application in the architecture of significantly enhanced hydrogel

Applied Physics Letters ◽

10.1063/1.2338007 ◽

2006 ◽

Vol 89 (8) ◽

pp. 083106 ◽

Cited By ~ 6

Author(s):

J. Y. Xiong ◽

X. Y. Liu ◽

J. L. Li ◽

J. Narayanan ◽

R. Y. Wang

Keyword(s):

Network Formation ◽

Hydrogel Network

Download Full-text

Network Formation Kinetics of Poly(dimethylsiloxane) Based on Step-Growth Polymerization

Macromolecules ◽

10.1021/acs.macromol.1c01131 ◽

2021 ◽

Vol 54 (17) ◽

pp. 7678-7689 ◽

Cited By ~ 1

Author(s):

Jie Jin ◽

Ru-Qiu Zheng ◽

Yin-Ning Zhou ◽

Zheng-Hong Luo

Keyword(s):

Network Formation ◽

Formation Kinetics ◽

Step Growth ◽

Step Growth Polymerization ◽

Kinetics Of

Download Full-text

New Hydrogel Network Based on Alginate and a Spiroacetal Copolymer

Gels ◽

10.3390/gels7040241 ◽

2021 ◽

Vol 7 (4) ◽

pp. 241

Author(s):

Alina Elena Sandu ◽

Loredana Elena Nita ◽

Aurica P. Chiriac ◽

Nita Tudorachi ◽

Alina Gabriela Rusu ◽

...

Keyword(s):

Thermal Stability ◽

Biomedical Applications ◽

Network Formation ◽

Bioactive Compound ◽

Synthetic Polymer ◽

Hybrid Gels ◽

Polymer Conjugate ◽

Hydrogel Network ◽

Important Approach ◽

Gel Network

This study reports a strategy for developing a biohybrid complex based on a natural/synthetic polymer conjugate as a gel-type structure. Coupling synthetic polymers with natural compounds represents an important approach to generating gels with superior properties and with potential for biomedical applications. The study presents the preparation of hybrid gels with tunable characteristics by using a spiroacetal polymer and alginate as co-partners in different ratios. The new network formation was tested, and the structure was confirmed by FTIR and SEM techniques. The physical properties of the new gels, namely their thermal stability and swelling behavior, were investigated. The study showed that the increase in alginate content caused a smooth increase in thermal stability due to the additional crosslinking bridges that appeared. Moreover, increasing the content of the synthetic polymer in the structure of the gel network ensures a slower release of carvacrol, the encapsulated bioactive compound.

Download Full-text

Analyzing Developing Brain-On-Chip Cultures with the CALIMA Calcium Imaging Tool

Micromachines ◽

10.3390/mi12040412 ◽

2021 ◽

Vol 12 (4) ◽

pp. 412

Author(s):

Elles A. L. Raaijmakers ◽

Nikki Wanders ◽

Rob M. C. Mestrom ◽

Regina Luttge

Keyword(s):

Calcium Imaging ◽

Network Formation ◽

Cell Activity ◽

Software Tool ◽

Large Data ◽

Published Data ◽

Data Sets ◽

Cellular Activity ◽

Process Data ◽

On Chip

Brain-on-chip (BoC) models are tools for reproducing the native microenvironment of neurons, in order to study the (patho)physiology and drug-response of the brain. Recent developments in BoC techniques focus on steering neurons in their activity via microfabrication and via computer-steered feedback mechanisms. These cultures are often studied through calcium imaging (CI), a method for visualizing the cellular activity through infusing cells with a fluorescent dye. CAlciumImagingAnalyser 2.0 (CALIMA 2.0) is an updated version of a software tool that detects and analyzes fluorescent signals and correlates cellular activity to identify possible network formation in BoC cultures. Using three previous published data sets, it was demonstrated that CALIMA 2.0 can analyze large data sets of CI-data and interpret cell activity to help study the activity and maturity of BoC cultures. Last, an analysis of the processing speed shows that CALIMA 2.0 is sufficiently fast to process data sets with an acquisition rate up to 5 Hz in real-time on a medium-performance computer.

Download Full-text