Temperature-Responsive Nanofibrillar Hydrogels for Cell Encapsulation

Abstract

Natural extracellular matrices often have a filamentous nature, however, only a limited number of artificial extracellular matrices have been designed from nanofibrillar building blocks. Here we report the preparation of temperature-responsive nanofibrillar hydrogels from rod-shaped cellulose nanocrystals (CNCs) functionalized with a copolymer of N-isopropylacrylamide and N,N'-dimethylaminoethyl methacrylate. The composition of the copolymer was tuned to achieve gelation of the suspension of copolymer-functionalized CNCs at 37 °C in cell culture medium and gel dissociation upon cooling it to room temperature. The mechanical properties and the structure of the hydrogel were controlled by changing copolymer composition and the CNC-to-copolymer mass ratio. The thermoreversible gels were used for the encapsulation and culture of fibroblasts and T cells and showed low cytotoxicity. Following cell culture, the cells were released from the gel by reducing the temperature, thus, enabling further cell characterization. These results pave the way for the generation of injectable temperature-responsive nanofibrillar hydrogels. The release of cells following their culture in the hydrogels would enable enhanced cell characterization and potential transfer in a different cell culture medium.

Nanofibrillar Stimulus‐Responsive Cholesteric Microgels with Catalytic Properties

“…Nanofibrillar CNC microgels offer structural integrity,c atalyst retention, and enhanced transportation of molecules to the microgel interior. [26] These features underline the potential of Ch-CNC microgels in catalysis.T he combination of these properties paves the way for the design and generation of multifunctional responsive materials with avariety of applications from natural resources.…”

“…[26] These features underline the potential of Ch-CNC microgels in catalysis.T he combination of these properties paves the way for the design and generation of multifunctional responsive materials with avariety of applications from natural resources. Themicrogel morphology (predetermined by the CNC organization in the precursor droplets) resulted in the isotropic or anisotropic swelling of microgels with ac oncentric or planar bipolar CNC organization, respectively.T he catalytic performance of the Ch-CNC microgels stemmed from the nucleophilic hydroxy groups on the CNC surface.F urthermore,o wing to the negative charge and reducing properties of the CNC component, the Ch-CNC microgels sequestered and reduced Ag + ions to plasmonic Ag NPs.T he resulting hybrid microgels showed catalytic performance in ar eduction reaction.…”

Chiral Carbon Dots Synthesized on Cellulose Nanocrystals

“…There is a growing interest in using CNCs in nanomedicine, due to their biocompatibility, as well as their asymmetric (rod‐like) shape facilitating prolonged blood circulation time and possible cellular uptake . Furthermore, the hydroxyl groups on the CNCs surface are amenable for attachment of polymer molecules or imaging and therapeutic agents .…”

“…enhancing the quality of imaging of biological species by suppressing background PL signal, due to, e.g., autofluorescence in the 400-550 nm spectral range. [66] There is a growing interest in using CNCs in nanomedicine, due to their biocompatibility, [67][68][69] as well as their asymmetric (rod-like) shape facilitating prolonged blood circulation time and possible cellular uptake. [70][71][72] Furthermore, the hydroxyl groups on the CNCs surface are amenable for attachment of polymer molecules [68,73] or imaging and therapeutic agents.…”

Supramolecular Nanofibrillar Thermoreversible Hydrogel for Growth and Release of Cancer Spheroids

“…The CNCs were surface‐functionalized with PNIPAM using reversible addition‐fragmentation chain‐transfer polymerization . The grafting density of the polymer was 0.09±0.04 polymer chains/nm 2 , that is, the same as the grafting density of the chain transfer agent (evaluated using inductively coupled plasma atomic emission spectroscopy).…”