TY - JOUR A1 - Koc, Julian A1 - Simovich, Tomer A1 - Schönemann, Eric A1 - Chilkoti, Ashutosh A1 - Gardner, Harrison A1 - Swain, Geoffrey W. A1 - Hunsucker, Kelli A1 - Laschewsky, André A1 - Rosenhahn, Axel T1 - Sediment challenge to promising ultra-low fouling hydrophilic surfaces in the marine environment JF - Biofouling : the journal of bioadhesion and biofilm research N2 - Hydrophilic coatings exhibit ultra-low fouling properties in numerous laboratory experiments. In stark contrast, the antifouling effect of such coatings in vitro failed when performing field tests in the marine environment. The fouling release performance of nonionic and zwitterionic hydrophilic polymers was substantially reduced compared to the controlled laboratory environment. Microscopy and spectroscopy revealed that a large proportion of the accumulated material in field tests contains inorganic compounds and diatomaceous soil. Diatoms adhered to the accumulated material on the coating, but not to the pristine polymer. Simulating field tests in the laboratory using sediment samples collected from the test sites showed that incorporated sand and diatomaceous earth impairs the fouling release characteristics of the coatings. When exposed to marine sediment from multiple locations, particulate matter accumulated on these coatings and served as attachment points for diatom adhesion and enhanced fouling. Future developments of hydrophilic coatings should consider accumulated sediment and its potential impact on the antifouling performance. KW - hydrogel KW - field test KW - fouling release KW - marine biofouling KW - sediment Y1 - 2019 U6 - https://doi.org/10.1080/08927014.2019.1611790 SN - 0892-7014 SN - 1029-2454 VL - 35 IS - 4 SP - 454 EP - 462 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Blocki, Anna A1 - Löwenberg, Candy A1 - Jiang, Yi A1 - Kratz, Karl A1 - Neffe, Axel T. A1 - Jung, Friedrich A1 - Lendlein, Andreas T1 - Response of encapsulated cells to a gelatin matrix with varied bulk and microenvironmental elastic properties JF - Polymers for advanced technologies N2 - Gelatin-based hydrogels offer various biochemical cues that support encapsulated cells and are therefore suitable as cell delivery vehicles in regenerative medicine. However, besides the biochemical signals, biomechanical cues are crucial to ensure an optimal support of encapsulated cells. Hence, we aimed to correlate the cellular response of encapsulated cells to macroscopic and microscopic elastic properties of glycidylmethacrylate (GMA)-functionalized gelatin-based hydrogels. To ensure that different observations in cellular behavior could be attributed to differences in elastic properties, an identical concentration as well as degree of functionalization of biopolymers was utilized to form covalently crosslinked hydrogels. Elastic properties were merely altered by varying the average gelatin-chain length. Hydrogels exhibited an increased degree of swelling and a decreased bulk elastic modulus G with prolonged autoclaving of the starting solution. This was accompanied by an increase of hydrogel mesh size and thus by a reduction of crosslinking density. Tougher hydrogels retained the largest amount of cells; however, they also interfered with cell viability. Softer gels contained a lower cell density, but supported cell elongation and viability. Observed differences could be partially attributed to differences in bulk properties, as high crosslinking densities interfere with diffusion and cell spreading and thus can impede cell viability. Interestingly, a microscopic elastic modulus in the range of native soft tissue supported cell viability and elongation best while ensuring a good cell entrapment. In conclusion, gelatin-based hydrogels providing a soft tissue-like microenvironment represent adequate cell delivery vehicles for tissue engineering approaches. Copyright (c) 2016 John Wiley & Sons, Ltd. KW - mechanotransduction KW - hydrogel KW - gelatin KW - cell encapsulation KW - matrix elasticity Y1 - 2017 U6 - https://doi.org/10.1002/pat.3947 SN - 1042-7147 SN - 1099-1581 VL - 28 SP - 1245 EP - 1251 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Dey, Pradip A1 - Adamovski, Miriam A1 - Friebe, Simon A1 - Badalyan, Artavazd A1 - Mutihac, Radu-Cristian A1 - Paulus, Florian A1 - Leimkühler, Silke A1 - Wollenberger, Ursula A1 - Haag, Rainer T1 - Dendritic polyglycerol-poly(ethylene glycol)-based polymer networks for biosensing application JF - ACS applied materials & interfaces N2 - This work describes the formation of a new dendritic polyglycerol-poly(ethylene glycol)-based 3D polymer network as a matrix for immobilization of the redox enzyme periplasmatic aldehyde oxidoreductase to create an electrochemical biosensor. The novel network is built directly on the gold surface, where it simultaneously stabilizes the enzyme for up to 4 days. The prepared biosensors can be used for amperometric detection of benzaldehyde in the range of 0.8-400 mu M. KW - biosensors KW - hydrogel KW - amperometry KW - dendritic Y1 - 2014 U6 - https://doi.org/10.1021/am502018x SN - 1944-8244 VL - 6 IS - 12 SP - 8937 EP - 8941 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schneider, Matthias A1 - Günter, Christina A1 - Taubert, Andreas T1 - Co-deposition of a hydrogel/calcium phosphate hybrid layer on 3D printed poly(lactic acid) scaffolds via dip coating BT - Towards Automated Biomaterials Fabrication JF - Polymers N2 - The article describes the surface modification of 3D printed poly(lactic acid) (PLA) scaffolds with calcium phosphate (CP)/gelatin and CP/chitosan hybrid coating layers. The presence of gelatin or chitosan significantly enhances CP co-deposition and adhesion of the mineral layer on the PLA scaffolds. The hydrogel/CP coating layers are fairly thick and the mineral is a mixture of brushite, octacalcium phosphate, and hydroxyapatite. Mineral formation is uniform throughout the printed architectures and all steps (printing, hydrogel deposition, and mineralization) are in principle amenable to automatization. Overall, the process reported here therefore has a high application potential for the controlled synthesis of biomimetic coatings on polymeric biomaterials. KW - 3D printing KW - dip-coating KW - poly(lactic acid) KW - PLA KW - calcium phosphate KW - gelatin KW - chitosan KW - hydrogel KW - calcium phosphate hybrid material KW - biomaterials Y1 - 2018 U6 - https://doi.org/10.3390/polym10030275 SN - 2073-4360 VL - 10 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Weiler, Markus A1 - Menzel, Christoph A1 - Pertsch, Thomas A1 - Alaee, Rasoul A1 - Rockstuhl, Carsten A1 - Pacholski, Claudia T1 - Bottom-Up Fabrication of Hybrid Plasmonic Sensors: Gold-Capped Hydrogel Microspheres Embedded in Periodic Metal Hole Arrays JF - Polymer : the international journal for the science and technology of polymers N2 - The high potential of bottom-up fabrication strategies for realizing sophisticated optical sensors combining the high sensitivity of a surface plasmon resonance with the exceptional properties of stimuli-responsive hydrogel is demonstrated. The sensor is composed of a periodic hole array in a gold film whose holes are filled with gold-capped poly(N-isoproyl-acrylamide) (polyNIPAM) microspheres. The production of this sensor relies on a pure chemical approach enabling simple, time-efficient, and cost-efficient preparation of sensor platforms covering areas of cm(2). The transmission spectrum of this plasmonic sensor shows a strong interaction between propagating surface plasmon polaritons at the metal film surface and localized surface plasmon resonance of the gold cap on top of the polyNIPAM microspheres. Computer simulations support this experimental observation. These interactions lead to distinct changes in the transmission spectrum, which allow for the simultaneous, sensitive optical detection of refractive index changes in the surrounding medium and the swelling state of the embedded polyNIPAM microsphere under the gold cap. The volume of the polyNIPAM microsphere located underneath the gold cap can be changed by certain stimuli such as temperature, pH, ionic strength, and distinct molecules bound to the hydrogel matrix facilitating the detection of analytes which do not change the refractive index of the surrounding medium significantly. KW - bottom-up KW - hydrogel KW - hole array KW - sensor KW - surface plasmon resonance Y1 - 2016 U6 - https://doi.org/10.1021/acsami.6b08636 SN - 1944-8244 VL - 8 SP - 26392 EP - 26399 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Tartivel, Lucile A1 - Blocki, Anna M. A1 - Braune, Steffen A1 - Jung, Friedrich A1 - Behl, Marc A1 - Lendlein, Andreas T1 - An Inverse shape-memory hydrogel scaffold switching upon cooling in a tissue-tolerated temperature range JF - Advanced materials interfaces N2 - Tissue reconstruction has an unmet need for soft active scaffolds that enable gentle loading with regeneration-directing bioactive components by soaking up but also provide macroscopic dimensional stability. Here microporous hydrogels capable of an inverse shape-memory effect (iSME) are described, which in contrast to classical shape-memory polymers (SMPs) recover their permanent shape upon cooling. These hydrogels are designed as covalently photo cross-linked polymer networks with oligo(ethylene glycol)-oligo(propylene glycol)-oligo(ethylene glycol) (OEG-OPG-OEG) segments. When heated after deformation, the OEG-OPG-OEG segments form micelles fixing the temporary shape. Upon cooling, the micelles dissociate again, the deformation is reversed and the permanent shape is obtained. Applicability of this iSME is demonstrated by the gentle loading of platelet-rich plasma (PRP) without causing any platelet activation during this process. PRP is highly bioactive and is widely acknowledged for its regenerative effects. Hence, the microporous inverse shape-memory hydrogel (iSMH) with a cooling induced pore-size effect represents a promising candidate scaffold for tissue regeneration for potential usage in minimally invasive surgery applications. KW - active scaffold KW - critical micellation temperature KW - hydrogel KW - inverse KW - shape-memory effect KW - platelet-rich plasma Y1 - 2022 U6 - https://doi.org/10.1002/admi.202101588 SN - 2196-7350 VL - 9 IS - 6 PB - Wiley CY - Hoboken ER -