The aim of this study was to investigate in situ crosslinking systems of anionic thiolated polymers. In order to accelerate the increase in dynamic viscosity of thiolated polymers (thiomers), they were combined with hydrogen peroxide, carbamide peroxide and ammonium persulfate. Thiomers (pectin-cysteine (Pec-Cys), sodium carboxymethylcellulose-cysteine (NaCMC-Cys) and poly(acrylic acid)-cysteine (PAA-Cys)) were synthesized via amide bond formation between the carboxylic acid group of polymers and the primary amino group of l-cysteine. The rheological properties of 1% (m/v) thiomer solutions with oxidizing agents were compared by oscillatory measurements over time (120 min). Pec-Cys and NaCMC-Cys with hydrogen and carbamide peroxide showed a sol-gel phase transition within a few minutes and scored up to 13,000-fold increase in dynamic viscosity. Furthermore, only thiomers exhibiting a polysaccharide backbone (Pec-Cys and NaCMC-Cys) showed a significant increase in viscosity (p < 0.05). In contrast, measurements of carbohydrate thiomers in combination with ammonium persulfate showed an initial increase in viscosity. Afterwards, a decrease in viscosity was observed likely caused by chain scission. According to these results, carbohydrate thiomer/oxidizing agent systems might be useful for various pharmaceutical applications such as for in situ gelling liquid/semisolid formulations or in tissue engineering.
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http://dx.doi.org/10.3109/03639045.2011.653813 | DOI Listing |
Biomacromolecules
January 2025
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense extracellular matrix (ECM) exhibiting high stiffness and fast stress relaxation. In this work, gelatin-based viscoelastic hydrogels were developed to mimic the compositions, stiffness, and fast stress relaxation of PDAC tissues. The hydrogels were cross-linked by gelatin-norbornene-boronic acid (GelNB-BA), thiolated macromers, and a 1,2-diol-containing linear synthetic polymer PHD.
View Article and Find Full Text PDFChemSusChem
January 2025
Dalian University of Technology, State Key Laboratory of Fine Chemicals, West Campus E-223, 2 Linggong Rd.,, Dalian, CHINA.
Developing high-activity and long-term stable electrocatalysts for electrochemical CO2 reduction reaction (eCO2RR) to valuable products is still a challenge. An in-depth understanding of reaction mechanisms and the structure-function relationship is required for the development of an advanced catalytic eCO2RR system. Herein, a coordination polymer of indium(III) and benzenehexathiol (BHT) was developed as an electrocatalyst (In-BHT) for eCO2RR to HCOO-, which displayed an outstanding catalytic performance over the entire pH range.
View Article and Find Full Text PDFBiofabrication
January 2025
Polymer Chemistry and Biomaterials (PBM) Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281, Building S4, 9000 Ghent, Belgium.
Volumetric bioprinting has revolutionized the field of biofabrication by enabling the creation of cubic centimeter-scale living constructs at faster printing times (in the order of seconds). However, a key challenge remains: developing a wider variety of available osteogenic bioinks that allow osteogenic maturation of the encapsulated cells within the construct. Herein, the bioink exploiting a step-growth mechanism (norbornene-norbornene functionalized gelatin in combination with thiolated gelatin-GelNBNBSH) outperformed the bioink exploiting a chain-growth mechanism (gelatin methacryloyl-GelMA), as the necessary photo-initiator concentration was three times lower combined with a more than 50% reduction in required light exposure dose resulting in an improved positive and negative resolution.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Pharmaceutics and Pharmaceutical Nanotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Protein Technology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address:
Recurrent aphthous stomatitis (RAS) is a common condition that manifests as ulcerative lesions in the oral mucosa. In this study, bilayer, mucoadhesive nanofibers loaded with pomegranate flower extract (PFE) were prepared using thiolated gelatin (TGel) and thiolated chitosan (TCS) as the active layer and drug-free polycaprolactone (PCL) as the backing layer. Gelatin (Gel) and chitosan (CS) were successfully thiolated (proven by Ellman's assay, solubility, H NMR, FTIR, Raman spectroscopy, and XRD) and electrospun into active nanofibrous layers with a diameter of 356.
View Article and Find Full Text PDFLangmuir
January 2025
Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Bio-functional Materials, Department of Materials Science and Engineering, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, P. R. China.
Steric stabilization and lubrication give loop polymer brushes enhanced antifouling properties. In the study, linear zwitterionic poly(NMASMCMS) brushes were first constructed on a poly(ethylene terephthalate) (PET) surface through surface-initiated reversible addition-fragmentation chain-transfer (SI-RAFT) polymerization. The tethered linear brushes on sheets were then thiolated with ethanolamine, followed by oxidation to form loop brushes.
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