Glycosidases have long been used for the synthesis of glycosides by transglycosylation reactions. Especially glycosidases from hyperthermophilic bacteria are useful for reactions under extreme reaction conditions, e.g.
View Article and Find Full Text PDFThermoresponsive copolymer microgels based on the biocompatible monomer N-vinylcaprolactam (VCL) and the hydrophobic comonomer 4-tert-butylcyclohexylacrylate (TBCHA) with highly tunable comonomers ratio were for the first time synthesized by miniemulsion polymerization. Their physical properties in aqueous solution and at the solid interface were characterized using dynamic light scattering (DLS), atomic force microscopy (AFM) and dissipative particle dynamics (DPD) simulations. The results show a significant decrease of the swelling rate of the obtained microgels with an increase of the amount of the hydrophobic comonomer.
View Article and Find Full Text PDFEnzyme immobilization has been widely used to improve the stability and recyclability of enzymes in industrial processes. In this work, a sortase-mediated and therefore selective covalent immobilization strategy (sortagging) for enzymes on microgels (GelZyms) was investigated. Aqueous microgels were synthesized from poly(-vinylcaprolactam)/glycidyl methacrylate (PVCL/GMA) and tagged with the sortase A recognition peptide sequence (LPETG) or its nucleophilic counterpart-tag (GGG).
View Article and Find Full Text PDFCurrent nanomedicine suffers from a big challenge due to the fact that most of the nanocarrier systems lack the desired tumor penetration depth, thereby limiting their clinical translation. Unlike the nanomaterials with a similar size or shape, microgels display excellent softness, fluidity and deformability, as well as stimuli-responsiveness in the tumor microenvironment. Herein, we report the synthesis of temperature-responsive poly(N-vinylcaprolactam)/oligo (ethylene glycol) acrylate/glycidyl methacrylate (PVCL/OEGA/GMA) microgels with different hydrodynamic radii (100-500 nm), crosslinking densities, 2-methoxyethyl acrylate (MEA) contents and OEGA chain lengths using a precipitation polymerization method and the investigation of the microgels in terms of their tumor penetration capability using a multicellular tumor spheroid (MCTS) model.
View Article and Find Full Text PDFHerein, the synthesis of amylose-coated, temperature-responsive poly(N-vinylcaprolactam) (VCL)-based copolymer microgels by enzyme-catalyzed grafting-from polymerization with phosphorylase b from rabbit muscle is reported. The phosphorylase is able to recognize the oligosaccharide maltoheptaose as primer and attach glucose units from the monomer glucose-1-phosphate to it, thereby forming amylose chains while releasing inorganic phosphate. Therefore, to enable the phosphorylase-catalyzed grafting-from polymerization of glucose-1-phosphate from the PVCL-based microgels, the maltoheptaose primer is covalently attached to the microgel in the first synthesis step.
View Article and Find Full Text PDFBiomacromolecules
September 2017
In this work we explored an enzyme-mediated method for selective and efficient decoration of aqueous microgels with biomolecules. Poly(N-vinylcaprolactam) (VCL) microgels with varied amounts of glycidyl methacrylate (GMA) as comonomer incorporated in the microgel shell were synthesized and characterized in regard to their size, swelling degree, and temperature-responsiveness in aqueous solutions. The surface of the PVCL/GMA microgel containing 5 mol % glycidyl methyacrylate was modified by grafting of a specific recognition peptide sequence (LPETG) for Sortase A from Staphylococcus aureus (Sa-SrtA).
View Article and Find Full Text PDFHerein we report the synthesis of biocompatible stimuli-responsive core-shell microgels consisting of a poly(N-vinylcaprolactam) (PVCL) core and a poly(2-methoxyethyl acrylate) (PMEA) corona via one-step surfactant-free precipitation copolymerization. The copolymerization process was investigated by reaction calorimetry, microgel growth was monitored by in situ dynamic light scattering and the chemical structure of core-shell microgels was characterized by Raman spectroscopy. It was possible to incorporate up to 32 mol% MEA into the PVCL/MEA microgels without loss of colloidal stability and broadening of the size distribution.
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