abstract
Biopolymer aerogels of appropriate open-porous morphology, nanotopology, surface chemistry, and mechanical properties can be promising cell scaffolding materials. Here, we report a facile approach towards the preparation of cellulose phosphate aerogels from two types of cellulosic source materials. Since high degrees of phosphorylation would afford water-soluble products inappropriate for cell scaffolding, products of low DSP (ca. 0.2) were prepared by a heterogeneous approach. Aiming at both i) full preservation of chemical integrity of cellulose during dissolution and ii) utilization of specific phase separation mechanisms upon coagulation of cellulose, TBAFH(>2)O/DMSO was employed as a non-derivatizing solvent. Sequential dissolution of cellulose phosphates, casting, coagulation, solvent exchange, and scCO(2) drying afforded lightweight, nano-porous aerogels. Compared to their non-derivatized counterparts, cellulose phosphate aerogels are less sensitive towards shrinking during solvent exchange. This is presumably due to electrostatic repulsion and translates into faster scCO(2) drying. The low DSP values have no negative impact on pore size distribution, specific surface (S-BET <= 310 m(2) g(-1)), porosity (Pi 95.5-97 vol.%), or stiffness (E rho <= 211 MPa cm(3) g(-1)). Considering the sterilization capabilities of scCO(2), existing templating opportunities to afford dual-porous scaffolds and the good hemocompatibility of phosphorylated cellulose, TBAFH(2)O/DMSO can be regarded a promising solvent system for the manufacture of cell scaffolding materials.
keywords
BACTERIAL CELLULOSE; FIBERS; REINFORCEMENT; PYROLYSIS; SCAFFOLDS
subject category
Biochemistry & Molecular Biology; Chemistry
authors
Schimper, CB; Pachschwoell, PS; Hettegger, H; Neouze, MA; Nedelec, JM; Wendland, M; Rosenau, T; Liebner, F
our authors
Wolfgang Falk Liebner
Invited Chair of Biorefinery and Bioeconomyacknowledgements
The financial support by the University of Natural Resources and Life Sciences, Vienna (BOKU), through the BOKU DOC Grant 2008 (Funder Id: 10.13039/501100006380) to C.B.S. is gratefully acknowledged.