Article
Engineering, Biomedical
Nicole E. Friend, Atticus J. McCoy, Jan P. Stegemann, Andrew J. Putnam
Summary: The formation of functional capillary blood vessels in engineered tissues remains a challenge. In this study, researchers investigated the effects of matrix properties on vessel network formation using PEG hydrogels. By varying the crosslinking ratio and incorporating cleavage sites, they found that reducing crosslinking or increasing degradability promoted vascularization and cell-mediated stiffening. These findings highlight the importance of cell-mediated remodeling for rapid vessel formation.
Article
Engineering, Biomedical
Alisa Rosenfeld, Tobias Goeckler, Mariia Kuzina, Markus Reischl, Ute Schepers, Pavel A. Levkin
Summary: Light-triggered degradation of hydrogels is essential for tissue engineering and bioprinting. A novel biocompatible and inherently photodegradable hydrogel has been developed for 3D cell culture, allowing for convenient and quick degradation via UV irradiation to produce structured hydrogels. Additionally, the study investigates the effects of hydrogel composition and swelling liquid on both photodegradability and biocompatibility.
ADVANCED HEALTHCARE MATERIALS
(2021)
Article
Polymer Science
Andrew Chung, Burak Tavsanli, Elizabeth R. Gillies
Summary: Hydrogels have diverse applications, and OPF has attracted attention for its tunable degradation. By introducing protected amines into OPF, the degradation rate can be controlled by triggering the cleavage of the polymer backbone. This approach can be applied to other stimuli, providing a versatile method to control OPF degradation.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Eva Mueller, Fei Xu, Todd Hoare
Summary: This study demonstrates the 3D printing of hydrazone-crosslinked POEGMA hydrogels using the FRESH technique and a low-cost extrusion bioprinter. The dynamic nature of the hydrazone cross-links allows for the reconfiguration of the gel structure and maintains the degradability of the scaffold. Moreover, the POEGMA hydrogels support cell adhesion and viability.
Article
Materials Science, Composites
Hatice Karaer Yagmur, Ismet Kaya
Summary: In this study, PU/Ag composites were synthesized in DMF without extra reducing agents, with DMF serving as both diluent and reducing agent for silver particles. Various analyses confirmed the formation of PU/Ag composites and showed that the composites have higher thermal stability compared to polyurethane. Conductivity measurements revealed different conductivity values for undoped PU and PU/Ag composites.
POLYMER COMPOSITES
(2021)
Article
Chemistry, Multidisciplinary
Ekkachai Martwong, Yvette Tran
Summary: The study reports on the synthesis and temperature-responsive properties of poly(PEGMA) hydrogel thin films. Surface-attached poly(PEGMA) hydrogel films were synthesized using a simple, versatile, and well-controlled thiol-ene click reaction method, with the transition temperature finely tunable by adjusting the number of PEG units. The LCST properties of the hydrogel films are not sensitive to salt, holding promise for applications in biology such as injectable hydrogels, drug delivery systems, microfluidic valves, and flow switches for biotechnologies.
Article
Chemistry, Multidisciplinary
Jinyoung Hwang, Phuong Le Thi, Simin Lee, Eun-Hye Park, Eunmi Lee, Eunmin Kim, Kiyuk Chang, Ki Dong Park
Summary: Although numerous poly(ethylene glycol) (PEG)-based bioadhesives have been developed and commercialized, their biocompatibility and bioactivity performances are generally lacking. To address these issues, chemically crosslinked gelatin-PEG adhesive hydrogels (GP) were designed through the enzymatic crosslinking reaction of horseradish peroxidase (HRP). The GP hydrogels exhibited adjustable mechanical and adhesive properties and effectively improved tissue adhesiveness and bioactivity. They also showed promising potential for hemostatic and wound healing treatments.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Polymer Science
Ionela Alice Podaru, Paul O. Stanescu, Raluca Ginghin, Stefania Stoleriu, Bogdan Tric, Raluca Somoghi, Mircea Teodorescu
Summary: This study investigates the synthesis and properties of nanocomposite hydrogels obtained by the aqueous solution free radical polymerization of N-vinylpyrrolidone (NVP) in the presence of Laponite XLG (XLG) as a crosslinker, and compares them with hydrogels prepared using conventional crosslinking agents. The results show that XLG is a better crosslinking agent than the conventional agent, leading to larger gel fractions and more homogeneous network hydrogels. Adding XLG as a second crosslinker significantly enhances the material properties.
Article
Chemistry, Multidisciplinary
Guodong Nian, Junsoo Kim, Xianyang Bao, Zhigang Suo
Summary: In this study, a novel method was developed to create hydrogels that are both swell-resistant and tough by densely entangling polymer chains at elevated temperatures and sparsely crosslinking them using UV light. This method is applicable to various synthetic and natural polymers and compatible with industrial processing technologies, opening doors to the development of sustainable and high-performance hydrogels.
ADVANCED MATERIALS
(2022)
Article
Polymer Science
Yuandou Wang, Shuxin Wang, Wenju Hu, Feng Su, Fusheng Liu, Suming Li
Summary: Amphiphilic block copolymers were synthesized and photo-crosslinked hydrogels were prepared. The hydrogels exhibited high swelling and excellent biocompatibility. Drug loading efficiency and release rate were dependent on the hydrogel properties. Hydrogels with higher drug concentration and shorter hydrophobic block length showed higher anti-cancer activity. Therefore, these hydrogels have great potential for long-term local cancer therapy.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2022)
Article
Materials Science, Biomaterials
Shuang Li, Dongyang Niu, Tuhe Shi, Wentao Yun, Shifeng Yan, Guohua Xu, Jingbo Yin
Summary: This study presents a novel design of injectable hydrogels via a Schiff base cross-linking reaction between adipic dihydrazide (ADH)-modified poly(L-glutamic acid) (PLGA-ADH) and benzaldehydeterminated poly(ethylene glycol) (PEG-CHO). The hydrogels showed good self-healing ability and biocompatibility with bone marrow-derived mesenchymal stem cells (BMSCs), promoting BMSC proliferation and deposition of glycosaminoglycans and upregulating the expression of cartilage-specific genes. In a rat cartilage defect model, the hydrogels significantly promoted new cartilage formation, indicating their potential in cartilage tissue engineering.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2023)
Article
Engineering, Biomedical
Nathan R. Richbourg, Nicholas A. Peppas
Summary: Synthetic hydrogels are commonly used as artificial 3D environments for studying cell-environment interactions, but their representation of physical properties of biological tissues is limited. This study successfully decoupled stiffness and solute transport in hydrogels by manipulating four structural parameters of multi-arm PEG hydrogel formulations. The results suggest that this approach is validated and applicable for decoupling stiffness and solute transport in hydrogels, enabling precise hydrogel design for investigating cell-environment interactions.
Article
Biochemistry & Molecular Biology
Julieta Paez, Adrian de Miguel-Jimenez, Rocio Valbuena-Mendoza, Aditi Rathore, Minye Jin, Alisa Glaser, Samuel Pearson, Aranzazu del Campo
Summary: In this study, the reactivity of the MS partner's heteroaromatic ring was optimized to slow down cross-linking kinetics and degradation of hydrogels. New MS substrates based on Tz and Bt rings were synthesized via simple pathways, extending the working time of precursor mixtures and allowing longer term cell culture. The Tz-based MS substrate was identified as the best candidate, supporting cell cultures for over 2 weeks.
Article
Biochemistry & Molecular Biology
Pawika Towongphaichayonte, Rangrong Yoksan
Summary: This study successfully fabricated polyelectrolyte complexes from mPEG-g-CTS and ALG, which could form fibrous network macrogels or spherical nanoparticles with different physicochemical properties depending on the mPEG chain length and weight ratios. These complexes have potential applications as carriers for functional food additives, drugs, and bioactive compounds.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Biochemistry & Molecular Biology
Mathilde Grosjean, Edouard Girard, Audrey Bethry, Gregory Chagnon, Xavier Garric, Benjamin Nottelet
Summary: This study designed degradable bioadhesives based on PEG-PLA star-shaped hydrogels and investigated the performance of acrylate, methacrylate, and catechol functional copolymers as bioadhesive hydrogels. The results showed that these bioadhesives reached adhesion strength comparable to commercial glues and exhibited low cytotoxicity, indicating their potential as surgical adhesives.
Article
Chemistry, Multidisciplinary
Antonino Cucinotta, Christophe Kahlfuss, Andrea Minoia, Samuel Eyley, Keanu Zwaenepoel, Gangamallaiah Velpula, Wim Thielemans, Roberto Lazzaroni, Veronique Bulach, Mir Wais Hosseini, Kunal S. Mali, Steven De Feyter
Summary: In this study, we achieved the expression and amplification of chirality in 2D metallosupramolecular networks formed by a nucleobase derivative. A racemic compound was obtained in the absence of coordinating metal ions, but spontaneous resolution occurred upon the addition of a coordinating ion or suitable guest molecule. The use of enantiopure solvent broke the mirror symmetry and resulted in a globally homochiral surface.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Ruth Cardinaels, An-Sofie Huysecom, Wim Thielemans, Paula Moldenaers
Summary: In this study, we investigate the temporary network topology and elasticity of micellar networks formed by hydrophobically associating multiblock copolymers. By using a combinatorics approach, we extend the mechano-statistical transient network model to multiblock copolymers and show that the micellar network microstructure can predict the concentration dependent elasticity. The network transitions from loop-dominated, poorly elastic structures with low functional cross-linking nodes at low concentrations to bridge-dominated, highly elastic structures with higher functional nodes at elevated concentrations.
Article
Chemistry, Applied
Zuxin Sun, Wim Thielemans
Summary: In this study, the cycling stability and capacitance performance of polypyrrole (PPy) electrode material were improved by doping with carboxylated cellulose nanocrystals (CNC-COO-) and commonly used salts. The results showed that the porous structure formed by doping enhanced the energy storage capacity and charging rate of the PPy-based films.
JOURNAL OF ENERGY CHEMISTRY
(2023)
Article
Pharmacology & Pharmacy
Maarten A. Mees, Fleur Boone, Thomas Bouwen, Frederik Vanaerschot, Charlotte Titeca, Hanna-Kaisa Vikkula, Leen Catrysse, Anja Vananroye, Erin Koos, Stelios Alexandris, Sabine Rosenfeldt, Samuel Eyley, Joachim Koetz, Geert van Loo, Wim Thielemans, Esther Hoste
Summary: High-mobility group box 1 (HMGB1) released during wounding delays skin regeneration. We discovered that dissolving glycyrrhizin in water forms a hydrogel with remarkable rheological properties. Glycyrrhizin-based hydrogels accelerate the closure of cutaneous wounds in normoglycemic and diabetic mice by influencing keratinocyte migration.
Article
Chemistry, Physical
Yong Zhou, Martine Trentesaux, Maya Marinova, Sergei Chernyak, Jean-Charles Morin, Melanie Dubois, Samuel Eyley, Wim Thielemans, Vlad Martin-Diaconescu, Andrei Khodakov, Jeremie Zaffran, Vitaly Ordomsky
Summary: In conventional bifunctional catalysts, active metal sites are associated with metal components, while acid sites are usually localized over oxide supports. The modification of metal sites by halogens provides an opportunity to generate acidity via the heterolytic dissociation of hydrogen directly over metal sites. High-throughput screening of different metal-halogen combinations reveals that only Pd and Pt catalysts demonstrate the formation of acid sites by interaction with Br, Cl, and I. Characterization and density functional theory (DFT) modeling suggest that hydrogen heterolytic dissociation occurs over halogens localized at the edges and corners of Pd and Pt nanoparticles, with the strength of the acid sites increasing with the electronegativity of the halogen.
Review
Polymer Science
Ineke Velghe, Bart Buffel, Veerle Vandeginste, Wim Thielemans, Frederik Desplentere
Summary: This review paper provides an overview of the state of the art on process-induced degradation of poly(lactic acid) (PLA) and the relative importance of different processing variables. The review focuses on degradation during melt processing techniques, such as injection molding and extrusion, and discusses general processing and fundamental variables, material properties for monitoring degradation, the effects of processing variables, and additives for melt stabilization. Despite existing knowledge on degradation reactions and their effects on PLA properties, gaps still remain in selecting and predicting processing conditions that minimize process-induced degradation.
Article
Chemistry, Multidisciplinary
Aleksei A. Turkin, Fatima Rammal, Samuel Eyley, Wim Thielemans, Ekaterina V. Makshina, Bert F. Sels
Summary: This study reveals the mechanism of catalyst poisoning by organic sulfur species in commercial 5-HMF feedstock during its hydroconversion. Various sulfur species were found to have a significant catalyst poisoning effect on HMF hydroconversion. The degree of poisoning is correlated with the thermodynamic favorability of metal sulfide formation. The presence of reduced sulfur species was identified as the ultimate metal poisoning agent, and their formation from more oxidized sulfur compounds explains the observed poisoning effect.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Biotechnology & Applied Microbiology
Sara P. Cuellar -Bermudez, Dries Bleus, Maarten A. Mees, Tom Struyf, Sanjaya Lama, Dries Vandamme, Peter Adriaensens, Roger Scherrers, Wim Thielemans, Wim Van den Ende, Ruddy Wattiez, Koenraad Muylaert
Summary: In this study, polysaccharides were isolated from an Arthrospira farm's spent culture medium and purified. These polysaccharides were rich in uronic acid, had low sulfate content, and contained various monosaccharides. The polysaccharides formed stable gel beads and exhibited stable gel properties. This research demonstrates the potential for using these recovered polysaccharides in food and biotechnological applications.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2023)
Article
Chemistry, Physical
An-Sofie Huysecom, Christ Glorieux, Jan Thoen, Wim Thielemans, Charles-Andre Fustin, Paula Moldenaers, Ruth Cardinaels
Summary: This article investigates the micellization process of block copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO). The results show that multiblock copolymers have lower transition temperatures and higher thermodynamic driving forces for micellization compared to triblock copolymers, due to the presence of multiple PPO blocks per chain. With increasing concentration, multiblock copolymers gradually form a viscoelastic network formed by soluble bridges in between micellar nodes, while triblock micelles jam into liquid crystalline phases resembling an elastic colloidal crystal.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Acoustics
Hamdi Ezzin, Souhail Dahmen, Zhenghua Qian, Christ Glorieux, Raj Das
Summary: This paper studies the dispersion curve of guided modes in a cubic Ni-Mn-Ga thin plate. It reports exceptional dispersion behavior with multiple crossings between antisymmetric (An) and symmetric (Sn) Lamb modes. In addition, several dispersion branches contain one or more zero group velocity (ZGV) points. The number of ZGV points per symmetric mode Sn and per antisymmetric mode An is found to be 3n-2.
Article
Nanoscience & Nanotechnology
Fanglei Guo, Wei Yu, Olivier Deschaume, Stijn Jooken, Liwang Liu, Qi Wei, Wim Thielemans, Carmen Bartic
Summary: In this study, a nanoparticle-based, light-controlled platform was developed to modulate the beating rate of cardiomyocytes. The platform utilized near-infrared stimulation and quantum dot thermometry for local temperature monitoring. This method is highly valuable for in vitro assays requiring control or synchronization of cell activities as well as thermobiology studies.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Niklas Herrmann, Cristina Martin, Samuel Eyley, Yusen Li, Nerea Bilbao, Victor Rubio-Gimenez, Mark Van der Auweraer, Wim Thielemans, Long Chen, Kunal S. Mali, Steven De Feyter
Summary: This article reports the rapid reaction kinetics of a 2D polymer based on imine, which is formed from a single monomer containing both aldehyde and amine groups. The results suggest a direct transition from monomer to crystalline polymer without an amorphous intermediate.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Yong Zhou, Martine Trentesaux, Maya Marinova, Sergei Chernyak, Jean-Charles Morin, Melanie Dubois, Samuel Eyley, Wim Thielemans, Vlad Martin-Diaconescu, Andrei Khodakov, Jeremie Zaffran, Vitaly Ordomsky
Summary: In conventional bifunctional catalysts, metal sites are responsible for catalytic activity, while acid sites are typically located on oxide supports. This study investigates the modification of metal sites with halogens to generate acidity through the heterolytic dissociation of hydrogen. High-throughput screening of different combinations of metals (Co, Ni, Ru, Pt, Pd, Rh) and halogens (Cl, Br, I) reveals that only Pd and Pt catalysts can form acid sites through interaction with Br, Cl, and I. Characterization and density functional theory (DFT) modeling suggest that hydrogen undergoes heterolytic dissociation over halogens located at the edges and corners of Pd and Pt nanoparticles, with the strength of the acid sites increasing with the electronegativity of the halogen.
Article
Materials Science, Multidisciplinary
Anna Trubetskaya, Jenni Leppiniemi, Sami Lipponen, Salvatore Lombardo, Wim Thielemans, Thaddeus Maloney, Timo Paeaekkoenen, Kavindra Kumar Kesari, Janne Ruokolainen, Vesa P. Hytoenen, Eero Kontturi
Summary: In this study, a thermoresponsive and biocompatible hydrogel composed of poly(N-isopropylacrylamide) (PNIPAAm) and cellulose nanocrystals (CNC) was developed. The hydrogel was generated through simple mixing without complicated derivatization, and its composition was optimized to enhance its stiffness. The hydrogel showed good compatibility with fibroblast cells and its thermoresponsive characteristics were observed. The findings suggest that this PNIPAAm-CNC hydrogel can be used as a versatile and affordable material for controllable 3D cell culture and may have potential applications in 3D-printing.
MATERIALS ADVANCES
(2023)
Article
Chemistry, Physical
Tim de la Croix, Nathalie Claes, Samuel Eyley, Wim Thielemans, Sara Bals, Dirk De Vos
Summary: This study investigates the potential of using heterogeneous platinum catalysts for the transfer dehydrogenation of long-chain alkanes, using ethylene as a hydrogen acceptor. The results show that the addition of tin to the catalyst leads to lower initial reaction rates but better resistance to catalyst deactivation and increased selectivity towards alkylaromatics.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)