Internal Composition versus the Mechanical Properties of Polyelectrolyte Multilayer Films: The Influence of Chemical Cross-Linking†

Langmuir ◽  
2009 ◽  
Vol 25 (24) ◽  
pp. 13809-13819 ◽  
Author(s):  
Thomas Boudou ◽  
Thomas Crouzier ◽  
Rachel Auzély-Velty ◽  
Karine Glinel ◽  
Catherine Picart
2004 ◽  
Vol 5 (2) ◽  
pp. 284-294 ◽  
Author(s):  
Ludovic Richert ◽  
Fouzia Boulmedais ◽  
Philippe Lavalle ◽  
Jérôme Mutterer ◽  
Emmanuelle Ferreux ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1066 ◽  
Author(s):  
Tim Huber ◽  
Sean Feast ◽  
Simone Dimartino ◽  
Wanwen Cen ◽  
Conan Fee

Cellulose-based hydrogels were prepared by dissolving cellulose in aqueous sodium hydroxide (NaOH)/urea solutions and casting it into complex shapes by the use of sacrificial templates followed by thermal gelation of the solution. Both the gelling temperatures used (40–80 °C), as well as the method of heating by either induction in the form of a water bath and hot press or radiation by microwaves could be shown to have a significant effect on the compressive strength and modulus of the prepared hydrogels. Lower gelling temperatures and shorter heating times were found to result in stronger and stiffer gels. Both the effect of physical cross-linking via the introduction of additional non-dissolving cellulosic material, as well as chemical cross-linking by the introduction of epichlorohydrin (ECH), and a combination of both applied during the gelation process could be shown to affect both the mechanical properties and microstructure of the hydrogels. The added cellulose acts as a physical-cross-linking agent strengthening the hydrogen-bond network as well as a reinforcing phase improving the mechanical properties. However, chemical cross-linking of an unreinforced gel leads to unfavourable bonding and cellulose network formation, resulting in drastically increased pore sizes and reduced mechanical properties. In both cases, chemical cross-linking leads to larger internal pores.


Langmuir ◽  
2018 ◽  
Vol 34 (21) ◽  
pp. 6109-6116 ◽  
Author(s):  
A. Salmatonidis ◽  
J. Hesselbach ◽  
G. Lilienkamp ◽  
T. Graumann ◽  
W. Daum ◽  
...  

2018 ◽  
Vol 41 (4) ◽  
pp. 223-235 ◽  
Author(s):  
Marcus S Niepel ◽  
Fadi Almouhanna ◽  
Bhavya K Ekambaram ◽  
Matthias Menzel ◽  
Andreas Heilmann ◽  
...  

Background: Cells possess a specialized machinery through which they can sense physical as well as chemical alterations in their surrounding microenvironment that affect their cellular behavior. Aim: In this study, we aim to establish a polyelectrolyte multilayer system of 24 layers of poly-l-lysine and hyaluronic acid to control stem cell response after chemical cross-linking. Methods and results: The multilayer build-up process is monitored using different methods, which show that the studied polyelectrolyte multilayer system grows exponentially following the islands and islets theory. Successful chemical cross-linking is monitored by an increased zeta potential toward negative magnitude and an extraordinary growth in thickness. Human adipose–derived stem cells are used here and a relationship between cross-linking degree and cell spreading is shown as cells seeded on higher cross-linked polyelectrolyte multilayer show enhanced spreading. Furthermore, cells that fail to establish focal adhesions on native and low cross-linked polyelectrolyte multilayer films do not proliferate to a high extent in comparison to cells seeded on highly cross-linked polyelectrolyte multilayer, which also show an increased metabolic activity. Moreover, this study shows the relation between cross-linking degree and human adipose–derived stem cell lineage commitment. Histological staining reveals that highly cross-linked polyelectrolyte multilayers support osteogenic differentiation, whereas less cross-linked and native polyelectrolyte multilayers support adipogenic differentiation in the absence of any specific inducers. Conclusion: Owing to the precise control of polyelectrolyte multilayer properties such as potential, wettability, and viscoelasticity, the system presented here offers great potential for guided stem cell differentiation in regenerative medicine, especially in combination with materials exhibiting a defined surface topography.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1787 ◽  
Author(s):  
Dae Hoon Lee ◽  
Atsushi Tamura ◽  
Yoshinori Arisaka ◽  
Ji-Hun Seo ◽  
Nobuhiko Yui

Tough mechanical properties are generally required for tissue substitutes used in regeneration of damaged tissue, as these substitutes must be able to withstand the external physical force caused by stretching. Gelatin, a biopolymer derived from collagen, is a biocompatible and cell adhesive material, and is thus widely utilized as a component of biomaterials. However, the application of gelatin hydrogels as a tissue substitute is limited owing to their insufficient mechanical properties. Chemical cross-linking is a promising method to improve the mechanical properties of hydrogels. We examined the potential of the chemical cross-linking of gelatin hydrogels with carboxy-group-modified polyrotaxanes (PRXs), a supramolecular polymer comprising a poly(ethylene glycol) chain threaded into the cavity of α-cyclodextrins (α-CDs), to improve mechanical properties such as stretchability and toughness. Cross-linking gelatin hydrogels with threading α-CDs in PRXs could allow for freely mobile cross-linking points to potentially improve the mechanical properties. Indeed, the stretchability and toughness of gelatin hydrogels cross-linked with PRXs were slightly higher than those of the hydrogels with the conventional chemical cross-linkers 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS). In addition, the hysteresis loss of gelatin hydrogels cross-linked with PRXs after repeated stretching and relaxation cycles in a hydrated state was remarkably improved in comparison with that of conventional cross-linked hydrogels. It is considered that the freely mobile cross-linking points of gelatin hydrogels cross-linked with PRXs attenuates the stress concentration. Accordingly, gelatin hydrogels cross-linked with PRXs would provide excellent mechanical properties as biocompatible tissue substitutes exposed to a continuous external physical force.


Soft Matter ◽  
2021 ◽  
Author(s):  
Libby Jane Marshall ◽  
Olga Matsarskaia ◽  
Ralf Schweins ◽  
Dave Adams

Exposure of lysine-containing peptide-based gelators to the cross-linking agent glutaraldehyde allows tuning of gel mechanical properties. The effect of cross-linking depends on the position of the lysine residue in the...


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 859 ◽  
Author(s):  
Gabriela Imbir ◽  
Aldona Mzyk ◽  
Klaudia Trembecka-Wójciga ◽  
Ewa Jasek-Gajda ◽  
Hanna Plutecka ◽  
...  

Surface functionalization of materials to improve their hemocompatibility is a challenging problem in the field of blood-contacting devices and implants. Polyelectrolyte multilayer films (PEMs), which can mimic functions and structure of an extracellular matrix (ECM), are a promising solution to the urgent need for functional blood-contacting coatings. The properties of PEMs can be easily tuned in order to provide a scaffold with desired physico-chemical parameters. In this study chitosan/chondroitin sulfate (Chi/CS) polyelectrolyte multilayers were deposited on medical polyurethane. Afterwards PEMs were modified by chemical cross-linking and nanoparticles introduction. Coatings with variable properties were tested for their hemocompatibility in the cone-plate tester under dynamic conditions. The obtained results enable the understanding of how substrate properties modulate PEMs interaction with blood plasma proteins and the morphotic elements.


Sign in / Sign up

Export Citation Format

Share Document