Applications of Nanocellulose/Nanocarbon Composites: Focus on Biotechnology and Medicine

Abstract

Nanocellulose/nanocarbon composites are newly emerging smart hybrid materials containing cellulose nanoparticles, such as nanofibrils and nanocrystals, and carbon nanoparticles, such as "classical" carbon allotropes (fullerenes, graphene, nanotubes and nanodiamonds), or other carbon nanostructures (carbon nanofibers, carbon quantum dots, activated carbon and carbon black). The nanocellulose component acts as a dispersing agent and homogeneously distributes the carbon nanoparticles in an aqueous environment. Nanocellulose/nanocarbon composites can be prepared with many advantageous properties, such as high mechanical strength, flexibility, stretchability, tunable thermal and electrical conductivity, tunable optical transparency, photodynamic and photothermal activity, nanoporous character and high adsorption capacity. They are therefore promising for a wide range of industrial applications, such as energy generation, storage and conversion, water purification, food packaging, construction of fire retardants and shape memory devices. They also hold great promise for biomedical applications, such as radical scavenging, photodynamic and photothermal therapy of tumors and microbial infections, drug delivery, biosensorics, isolation of various biomolecules, electrical stimulation of damaged tissues (e.g., cardiac, neural), neural and bone tissue engineering, engineering of blood vessels and advanced wound dressing, e.g., with antimicrobial and antitumor activity. However, the potential cytotoxicity and immunogenicity of the composites and their components must also be taken into account.

Keywords: carbon nanotubes; cellulose nanocrystals; diamond nanoparticles; drug delivery; fullerenes; graphene; nanofibrillated cellulose; sensors; tissue engineering; wound dressing.

Figure A1

Human adipose tissue-derived stem cells (hASC) and porcine adipose tissue-derived stem cells (pASC) on days 1 and 7 after seeding on a cellulose mesh with thick or thin CNF+MWCNT coating (column (a) and (b), respectively), with CNF coating (column (c)), and without any coating (column (d)). Cells were stained by immunofluorescence for vinculin (green), with TRITC-conjugated phalloidin for F-actin (red) and with Hoechst #33258 for the nuclei (blue). Cellulose mesh had autofluorescence in the blue channel. Dragonfly 503 spinning disk confocal microscope with a Zyla 4.2 PLUS sCMOS camera, objective HC PL APO 20x/0.75 IMM CORR CS2. Scale bar: 50 µm.

Figure A2

Lab-made dynamic cultivation system for pressure stimulation of cells on the tested material samples. The whole system in a cell incubator (a); detail of a cultivation chamber (b).

Figure A3

Porcine adipose tissue-derived stem cells (pASC) cultivated in a conventional static cell culture system for four days or in a pressure-generating dynamic cell culture system for three days (after one day of static cultivation). The cells were grown on a cellulose mesh with thick or thin CNF + MWCNT coating (column (a) and (b), respectively), with CNF coating (column (c)), and without any coating (column (d)). Cells were stained by immunofluorescence for vinculin (green), with TRITC-conjugated phalloidin for F-actin (red) and with DAPI for the nuclei (blue). Cellulose mesh had autofluorescence in the blue channel. Dragonfly 503 spinning disk confocal microscope with a Zyla 4.2 PLUS sCMOS camera, objective HC PL APO 20x/0.75 IMM CORR CS2. Scale bar: 50 µm.

Figure 1

Scheme of fullerene C₆₀ (a) and of the preparation and structure of nanocellulose/fullerene composites (b).

Figure 2

Scheme of graphene (a) and of the preparation and structure of nanocellulose/graphene composites (b).

Figure 3

Scheme of multi-walled and single-walled carbon nanotubes (a) and of the preparation and structure of nanocellulose/carbon nanotube composites (b).

Figure 4

Scheme of a nanodiamond (a) and of the preparation and structure of nanocellulose/nanodiamond composites (b).