Effect of Sulfation Route and Subsequent Oxidation on Derivatization Degree and Biocompatibility of Cellulose Sulfates

• Published in: Macromolecular bioscience 2020-02, Vol.20 (2), p.e1900403-n/a
• Main Authors: Strätz, Juliane, Liedmann, Andrea, Heinze, Thomas, Fischer, Steffen, Groth, Thomas
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; Amino groups; Animals; Aqueous solutions; Biocompatibility; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Biological activity; Biomedical materials; Biopolymers; Cellulose; Cellulose - analogs & derivatives; Cellulose - chemistry; Cellulose - pharmacology; cellulose sulfates; Fibroblasts; Heparin; Hydrogels; Magnetic resonance spectroscopy; Malaprade oxidation; Materials Testing; Mice; mouse fibroblasts; NMR; NMR spectroscopy; Nuclear magnetic resonance; Oxidation; Oxidation-Reduction; Sulfates; Sulfation; Toxicity
• ISSN: 1616-5187; 1616-5195
• DOI: 10.1002/mabi.201900403

Sulfated cellulose (CS) represents an interesting biopolymer due to bioactivity comparable to heparin. However, use of CS for making surface coatings or hydrogels requires the presence of reactive groups for covalent reactions. Here, an approach is presented to oxidize cellulose sulfates for subsequent cross‐linking reactions with amino groups to form imine bonds. Cellulose is sulfated by direct sulfation or acetosulfation, followed by a Malaprade oxidation. The CS obtained is characterized by elemental analysis and 13C‐NMR spectroscopy. The resulting oxidized cellulose sulfates (oxCS) have different degrees of sulfation ranging from 0.79 to 1.13 and oxidation degrees from 0.18 to 0.34, but also different mass average molecular mass (MW). Toxicity studies are carried out with mouse 3T3 fibroblasts exposed to aqueous solutions of oxCS. The results show that all oxCS are non‐toxic at lower concentrations (0.5 mg mL−1), but with both increasing degree of oxidation and concentrations, toxic effects are observed particularly for acetosulfated and lesser for direct sulfated oxCS, which is related to a decrease in the MW of the products. It is concluded that oxCS obtained by direct sulfation with MW above 70 kDa may represent a biocompatible material for the applications suggested above. Cellulose sulfate has a bioactivity comparable to heparin, but needs reactive groups to form covalent bonds with pendant groups for making surface coatings or hydrogels. Different routes of sulfation of cellulose and subsequent oxidation are explored and products are characterized toward molecular composition and toxicity on mouse 3T3 fibroblasts.