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https://hdl.handle.net/1822/26073
Título: | Carboxymethylation of ulvan and chitosan and their use as polymeric components of bone cements |
Autor(es): | Barros, Alexandre A. Alves, A. Nunes, Cláudia Coimbra, Manuel A. Pires, R. A. Reis, R. L. |
Palavras-chave: | Bone cements Ionomer cements Ulvan Chitosan Carboxymethylation Glass-ionomers |
Data: | Nov-2013 |
Editora: | Elsevier |
Revista: | Acta Biomaterialia |
Resumo(s): | Ulvan, extracted from the green algae Ulva lactuca, and chitosan, extracted from Loligo forbesis squid-pen, were carboxymethylated, 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 Fourier transform infrared spectroscopy and quantified by conductimetric titration and 1H nuclear magnetic resonance. The average molecular weight increased with the carboxymethylation (chitosan, Mn 145→296 kDa and Mw 227→416 kDa; ulvan, Mn 139→261 kDa and Mw 368→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 52.4 ± 8.0 MPa and modulus 2.3 ± 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. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/26073 |
DOI: | 10.1016/j.actbio.2013.06.036 |
ISSN: | 1742-7061 |
Versão da editora: | http://www.sciencedirect.com/science/article/pii/S1742706113003292# |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | 3B’s - Artigos em revistas/Papers in scientific journals |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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17566-1-s2.0-S1742706113003292-main.pdf Acesso restrito! | 1,16 MB | Adobe PDF | Ver/Abrir |