78
antioxidant that can scavenge superoxide and hydroxyl radicals. Ugartondo et al.
(2009) incubated normal human RBC in the presence of lignin, and noted an inhibitory effect against the lipid peroxidation of RBC induced by oxygen radicals.
Cellulose fibers are widely used in several areas, such as in the medical field.
However, microbial growth on the cellulose fiber-based materials causes the hydrolysis, oxidation and fission of cellulose chains (Silva et al. 2011). These changes
have a bad influence on the properties of the material and even increase the risk of
infection in the medical field. These negative effects can be controlled by modifying
cellulose fiber. Li and Peng (2015) designed a modification method by constructing
chitosan (Cs)/LS multilayers on the surface of cellulose fibers. The cellulose fiber
materials obtained showed a higher antimicrobial activity against Escherichia coli
than the unmodified ones. Due to the presence of LSs as an antioxidant, the zerospan tensile strength of the modified fibers and the degree of polymerization did not
change after the 2,2-azobis(2-amidinopropane) dihydrochloride-initiated oxidation
treatment. Jiang et al. (2015) prepared the multi-arm carriers composed of lignin
core and arms derivatived from poly(glycidyl methacrylate)-co-PEGMA (PGMAco- PEGMA) for gene delivery. Ethanolamine was functionalized onto ligninPGMA- co-PEGMA
and
a
lignin-poly(2-(β-D-glucosyloxy)
ethyl
acrylate)-co-PEGMA (PGEA-co-PEGMA) copolymer consisting of a lignin core
and different length PGEA-co-PEGMA side chains was produced by Jiang et al.
(2015). The excellent antioxidant activity gave a good biocompability to the copolymers and attenuated oxidative stress. Evaluation of its gene transfection efficiency
in human hepatoma cell line (Hep G 2 ) and human embryonic kidney (HEK 293 T)
cells suggested that the lignin-PGMA-co-PEGMA copolymers can potentially be
used as a gene delivery vector in vivo. The transfection efficiency of the copolymers
depended largely on the molar ratios of nitrogen in the polymer to phosphate in the
plasmid DNA (Jiang et al. 2015). In addition to serving as a gene delivery vector,
lignin can also function as a drug-loaded film (Li et al. 2017). Trans-resveratrol is a
useful agent to prevent degenerative neurological disorders, the development of cardiovascular diseases and cancer (Rauf et al. 2017). However, low solubility and
photostability greatly restrict its practical use (Liu et al. 2018). Lignin has an ascendant power in UV resistance and can be used for the preservation of trans- resveratrol.
Liu et al. (2018) developed poly(L-lactide)/lignin-graft-poly(D-lactide) film loaded
with trans-resveratrol. The films containing trans-resveratrol had a good performance in terms of mechanical properties, dispersion homogeneity and photolysis
resistance (Liu et al. 2018).
Recently, nanoscale lignin for biomaterial applications has attracted great attention among researchers. Tissue-engineered nerve transplantation can be used as an
alternative to autologous nerve transplantation for peripheral nerve repair (Carriel
et al. 2014). However, oxidative stress generated by transplant rejection can cause
the failure of the implants and the death of the grafted cells. The development of
nerve tissue-engineered grafts with antioxidant activity may be an appropriate way
to solve the problem. Wang et al. (2018b) synthesized polycaprolactone (PCL)/lignin-PCL nanofibers as scaffolds to support the growth of Schwann cells and dorsal
root ganglion (DRG) neurons. The addition of lignin-PCL gave nanofibers good
Z. Qin et al.
antioxidant that can scavenge superoxide and hydroxyl radicals. Ugartondo et al.
(2009) incubated normal human RBC in the presence of lignin, and noted an inhibitory effect against the lipid peroxidation of RBC induced by oxygen radicals.
Cellulose fibers are widely used in several areas, such as in the medical field.
However, microbial growth on the cellulose fiber-based materials causes the hydrolysis, oxidation and fission of cellulose chains (Silva et al. 2011). These changes
have a bad influence on the properties of the material and even increase the risk of
infection in the medical field. These negative effects can be controlled by modifying
cellulose fiber. Li and Peng (2015) designed a modification method by constructing
chitosan (Cs)/LS multilayers on the surface of cellulose fibers. The cellulose fiber
materials obtained showed a higher antimicrobial activity against Escherichia coli
than the unmodified ones. Due to the presence of LSs as an antioxidant, the zerospan tensile strength of the modified fibers and the degree of polymerization did not
change after the 2,2-azobis(2-amidinopropane) dihydrochloride-initiated oxidation
treatment. Jiang et al. (2015) prepared the multi-arm carriers composed of lignin
core and arms derivatived from poly(glycidyl methacrylate)-co-PEGMA (PGMAco- PEGMA) for gene delivery. Ethanolamine was functionalized onto ligninPGMA- co-PEGMA
and
a
lignin-poly(2-(β-D-glucosyloxy)
ethyl
acrylate)-co-PEGMA (PGEA-co-PEGMA) copolymer consisting of a lignin core
and different length PGEA-co-PEGMA side chains was produced by Jiang et al.
(2015). The excellent antioxidant activity gave a good biocompability to the copolymers and attenuated oxidative stress. Evaluation of its gene transfection efficiency
in human hepatoma cell line (Hep G 2 ) and human embryonic kidney (HEK 293 T)
cells suggested that the lignin-PGMA-co-PEGMA copolymers can potentially be
used as a gene delivery vector in vivo. The transfection efficiency of the copolymers
depended largely on the molar ratios of nitrogen in the polymer to phosphate in the
plasmid DNA (Jiang et al. 2015). In addition to serving as a gene delivery vector,
lignin can also function as a drug-loaded film (Li et al. 2017). Trans-resveratrol is a
useful agent to prevent degenerative neurological disorders, the development of cardiovascular diseases and cancer (Rauf et al. 2017). However, low solubility and
photostability greatly restrict its practical use (Liu et al. 2018). Lignin has an ascendant power in UV resistance and can be used for the preservation of trans- resveratrol.
Liu et al. (2018) developed poly(L-lactide)/lignin-graft-poly(D-lactide) film loaded
with trans-resveratrol. The films containing trans-resveratrol had a good performance in terms of mechanical properties, dispersion homogeneity and photolysis
resistance (Liu et al. 2018).
Recently, nanoscale lignin for biomaterial applications has attracted great attention among researchers. Tissue-engineered nerve transplantation can be used as an
alternative to autologous nerve transplantation for peripheral nerve repair (Carriel
et al. 2014). However, oxidative stress generated by transplant rejection can cause
the failure of the implants and the death of the grafted cells. The development of
nerve tissue-engineered grafts with antioxidant activity may be an appropriate way
to solve the problem. Wang et al. (2018b) synthesized polycaprolactone (PCL)/lignin-PCL nanofibers as scaffolds to support the growth of Schwann cells and dorsal
root ganglion (DRG) neurons. The addition of lignin-PCL gave nanofibers good
Z. Qin et al.