Water-based carbodiimide mediated synthesis of polysaccharide-amino acid conjugates: Deprotection, charge and structural analysis

Organic acid cross-linked 3D printed cellulose nanocomposite bioscaffolds with controlled porosity, mechanical strength, and biocompatibility

“…The Ink 0 /120°C ( Figure S7 B) showed the characteristic peaks because of the carbon atoms of NFC or CMC appeared at δ C 61 (C6), 70–80 (C2, C3, C5, and C7), 81 (C4), and 105 ppm (C1; the respective carbons are numbered in Figure 6 ). Besides this, the carboxyl carbon (C8) of the CMC carboxylate group is observed at δ C 178 ppm ( Dobaj Štiglic et al., 2021 ; Gürer et al., 2021 ; Mohan et al., 2020 ) (see Figure S7 ). All these characteristic peaks are also observed for CA cross-linked sample (Ink 2.5 /120°C/N, Figure 6 A), in addition to the methylene carbon atoms of CA at δ C 45 ppm (C2∗-C4∗) ( Sun et al., 2019 ).…”

“…Recently, we used a combination of NFC and CMC for DIW ( Mohan et al., 2020 ). CMC, a derivative of the natural polymer cellulose, is inexpensive, biocompatible, water soluble, has pH-dependent solubility and charge, and can be easily cross-linked/modified with various functional molecules ( Gürer et al., 2021 ). It is structurally similar to NFC and exhibits a natural affinity to NFC through interfacial adhesion.…”

3D Printed Porous Nanocellulose-Based Scaffolds As Carriers for Immobilization of Glycosyltransferases

“…Figure shows the ATR-IR spectra of non-cross-linked and CA cross-linked scaffolds. The spectra of the neat polymers (see Figure S3, Supporting Information) show all characteristic peaks for NFC (OH, 3337 cm –1 ; CH, 2910 cm –1 ; C–O, 1100 cm –1 ) and CMC (OH, 3298 cm –1 ; CH, 2910 cm –1 ; COOH, 1590 cm –1 ; C–O, 1100 cm –1 ). ,, All these peaks were also observed for the non-cross-linked scaffold (NC/CA0,Figure A). Interestingly, in addition to the CMC-carboxyl carbonyl peak at 1590 cm –1 , a new peak at 1730 cm –1 associated with ester carbonyl was observed in the CA cross-linked samples (Figure A and B) .…”

Regioselective synthesis of polysaccharide–amino acid ester conjugates

“…The indole structure is highly stable (Pino-Rios & Solà, 2020); extensive delocalization of the nitrogen lone pair of nitrogen reduces its nucleophilicity (Anderson & Liu, 2000). Kleinschek et al also concluded that the α-amine of L-tryptophan methyl ester can react with carboxyls via EDC coupling, but the amine at its side chain cannot (Gürer et al, 2021).…”

“…Some downstream Maillard products may be toxic, causing issues including oxidative stress and inflammation in vivo (Zhou et al, 2021). Esterification of polysaccharide hydroxyls using Boc-protected amino acids (Hotzel et al, 2019;Zink et al, 2019), and EDC/NHS coupling of amino acids with carboxymethyl cellulose (Gürer et al, 2021) have been reported, but they are not regioselective methods.…”