TY  - JOUR
A1  - Piluso, Susanna
A1  - Vukicevie, Radovan
A1  - Nöchel, Ulrich
A1  - Braune, Steffen
A1  - Lendlein, Andreas
A1  - Neffe, Axel T.
T1  - Sequential alkyne-azide cycloadditions for functionalized gelatin hydrogel formation
JF  - European polymer journal
N2  - While click chemistry reactions for biopolymer network formation are attractive as the defined reactions may allow good control of the network formation and enable subsequent functionalization, tailoring of gelatin network properties over a wide range of mechanical properties has yet to be shown. Here, it is demonstrated that copper-catalyzed alkyne-azide cycloaddition of alkyne functionalized gelatin with diazides gave hydrogel networks with properties tailorable by the ratio of diazide to gelatin and diazide rigidity. 4,4′-diazido-2,2′-stilbenedisulfonic acid, which has been used as rigid crosslinker, yielded hydrogels with Young’s moduli E of 50–390 kPa and swelling degrees Q of 150–250 vol.%, while the more flexible 1,8-diazidooctane resulted in hydrogels with E = 125–280 kPa and Q = 225–470 vol.%. Storage moduli could be varied by two orders of magnitude (G′ = 100–20,000 Pa). An indirect cytotoxicity test did not show cytotoxic properties. Even when employing 1:1 ratios of alkyne and azide moieties, the hydrogels were shown to contain both, unreacted alkyne groups on the gelatin backbone as well as dangling chains carrying azide groups as shown by reaction with functionalized fluorescein. The free groups, which can be tailored by the employed ratio of the reactants, are accessible for covalent attachment of drugs, as was demonstrated by functionalization with dexamethasone. The sequential network formation and functionalization with click chemistry allows access to multifunctional materials relevant for medical applications.
KW  - Click chemistry
KW  - Hydrogel
KW  - Polymer functionalization
KW  - Biopolymer
KW  - Rheology
KW  - Multifunctionality
Y1  - 2018
U6  - https://doi.org/10.1016/j.eurpolymj.2018.01.017
SN  - 0014-3057
SN  - 1873-1945
VL  - 100
SP  - 77
EP  - 85
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Richter, Marina Juliane
A1  - Schulz, Alexander
A1  - Subkowski, Thomas
A1  - Böker, Alexander
T1  - Adsorption and rheological behavior of an amphiphilic protein at oil/water interfaces
JF  - Journal of colloid and interface science
N2  - Hydrophobins are highly surface active proteins which self-assemble at hydrophilic-hydrophobic interfaces into amphipathic membranes. We investigate hydrophobin self-assembly at oil/water interfaces to deepen the understanding of protein behavior in order to improve our biomimetic synthesis. Therefore, we carried out pendant drop measurements of hydrophobin stabilized oil/water systems determining the time-dependent IFT and the dilatational rheology with additional adaptation to the Serrien protein model. We show that the class I hydrophobin H*Protein B adsorbs at an oil/water interface where it forms a densely-packed interfacial protein layer, which dissipates energy during droplet oscillation. Furthermore, the interfacial protein layer exhibits shear thinning behavior. (C) 2016 Elsevier Inc. All rights reserved.
KW  - Hydrophobin
KW  - Self-assembly
KW  - Pendant drop tensiometry
KW  - IFT
KW  - Rheology
Y1  - 2016
U6  - https://doi.org/10.1016/j.jcis.2016.06.062
SN  - 0021-9797
SN  - 1095-7103
VL  - 479
SP  - 199
EP  - 206
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Piluso, Susanna
A1  - Hiebl, Bernhard
A1  - Gorb, Stanislav N.
A1  - Kovalev, Alexander
A1  - Lendlein, Andreas
A1  - Neffe, Axel T.
T1  - Hyaluronic acid-based hydrogels crosslinked by copper-catalyzed azide-alkyne cycloaddition with tailorable mechanical properties
JF  - The international journal of artificial organs
N2  - Biopolymers of the extracellular matrix are attractive starting materials for providing degradable and biocompatible biomaterials. In this study, hyaluronic acid-based hydrogels with tunable mechanical properties were prepared by the use of copper-catalyzed azide-alkyne cycloaddition (known as "click chemistry"). Alkyne-functionalized hyaluronic acid was crosslinked with linkers having two terminal azide functionalities, varying crosslinker density as well as the lengths and rigidity of the linker molecules. By variation of the crosslinker density and crosslinker type, hydrogels with elastic moduli in the range of 0.5-4 kPa were prepared. The washed materials contained a maximum of 6.8 mg copper per kg dry weight and the eluate of the gel crosslinked with diazidostilbene did not show toxic effects on L929 cells. The hyaluronic acid-based hydrogels have potential as biomaterials for cell culture or soft tissue regeneration applications.
KW  - Biomaterial
KW  - Hydrogel
KW  - Hyaluronic acid
KW  - Microindentation
KW  - Rheology
Y1  - 2011
U6  - https://doi.org/10.5301/IJAO.2011.6394
SN  - 0391-3988
VL  - 34
IS  - 2
SP  - 192
EP  - 197
PB  - Wichtig
CY  - Milano
ER  -