@article {17566, title = {Carboxymethylation of ulvan and chitosan and their use as polymeric components of bone cements}, journal = {Acta Biomaterialia}, year = {2013}, month = {2013-06-21 00:00:00}, abstract = {

We carboxymethylated ulvan, extracted from the green algae\ Ulva lactuca, and chitosan, extracted fromLoligo forbesis\ squid-pen, yielding polysaccharides with an average degree of substitution of \~{}98\% (carboxymethyl ulvan, CMU) and \~{}87\% (carboxymethyl chitosan, N,O-CMC). The carboxymethylation was confirmed by FTIR and quantified by conductimetric titration and\ 1H NMR. The average molecular weight increased with the carboxymethylation (chitosan: Mn\ 145{\textrightarrow}296 kDa and Mw\ 227{\textrightarrow}416 kDa; ulvan: Mn139{\textrightarrow}261 kDa and Mw\ 368{\textrightarrow}640 kDa) indicating successful chemical modifications. Mixtures of the modified polysaccharides were tested in the formulation of polyacrylic acid-free glass-ionomer bone cements. Mechanical and\ in vitro\ bioactivity tests indicate that the inclusion of CMU in the cement formulation, i.e. 0.50:0.50 N,O-CMC:CMU, enhances its mechanical performance (compressive strength of 52.4 {\textpm} 8.0 MPa and modulus of 2.3 {\textpm} 0.3 GPa), generates non-cytotoxic cements and induces the diffusion of Ca and/or P-based moieties from the surface to the bulk of the cements.

}, keywords = {Bone cements, ionomer cements}, doi = {10.1016/j.actbio.2013.06.036}, url = {http://www.sciencedirect.com/science/article/pii/S1742706113003292$\#$}, author = {Barros, A. A. and Alves, A. and Nunes, C. and Coimbra, M. A. and Pires, R. A. and Reis, R. L.} }