Orellana BR, Hilt JZ, Puleo DA. Drug release from calcium sulfate-based composites.
J Biomed Mater Res B Appl Biomater 2014;
103:135-42. [PMID:
24788686 DOI:
10.1002/jbm.b.33181]
[Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 03/11/2014] [Accepted: 04/05/2014] [Indexed: 12/24/2022]
Abstract
To help reduce the need for autografts, calcium sulfate (CS)-based bone graft substitutes are being developed to provide a stable platform to aid augmentation while having the ability to release a broad range of bioactive agents. CS has an excellent reputation as a biocompatible and osteoconductive substance, but addition of bioactive agents may further enhance these properties. Samples were produced with either directly loaded small, hydrophobic molecule (i.e., simvastatin), directly loaded hydrophilic protein (i.e., lysozyme), or 1 and 10 wt % of fast-degrading poly(β-amino ester) (PBAE) particles containing protein. Although sustained release of directly loaded simvastatin was achieved, direct loading of small amounts of lysozyme resulted in highly variable release. Direct loading of a larger amount of protein generated a large burst, 65% of total loading, followed by sustained release of protein. Release of lysozyme from 1 wt % of PBAE particles embedded into CS was more controllable than when directly loaded, and for 10 wt % of protein-loaded PBAE particles, a higher burst was followed by sustained release, comparable to the results for the high direct loading. Compression testing determined that incorporation of directly loaded drug or drug-loaded PBAE particles weakened CS. In particular, PBAE particles had a significant effect on the strength of the composites, with a 25 and 80% decrease in strength for 1 and 10 wt % particle loadings, respectively. CS-based composites demonstrated the ability to sustainably release both macromolecules and small molecules, supporting the potential for these materials to release a range of therapeutic agents.
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