TY - JOUR
T1 - In vivo tissue response to resorbable silica xerogels as controlled-release materials
AU - Radin, Shula
AU - El-Bassyouni, Gehan
AU - Vresilovic, Edward
AU - Schepers, Evert
AU - Ducheyne, Paul
PY - 2005/3/1
Y1 - 2005/3/1
N2 - Biodegradable, controlled-release carrier materials with non-toxic degradation products are valuable for local delivery of biologically active molecules. Previously, it was shown that room-temperature processed silica sol-gels (or xerogels) are porous, resorbable materials that can release molecules of various sizes in a controlled, time dependent manner. Previous in vitro studies also demonstrated benefits of silica xerogels as controlled-release materials for the treatment of bone infections. Herein the tissue and cell response to xerogels is documented using a subacute implantation procedure. The tissue response was correlated to composition, surface properties, resorption rate and incorporation of the antibiotic vancomycin. Ca- and P-free and Ca- and P-containing xerogels, with and without apatite (AP) surface, were used. Xerogels were implanted either as discs in a subcutaneous site, or as granules in the iliac crest of New Zealand white rabbits. The samples with surrounding tissue were retrieved after 2 and 4 weeks of implantation. Silica xerogels implanted either as discs subcutaneously or as granules in the iliac crest showed a favorable tissue response. The granules, either with or without Ca and P content, gradually resorbed over time. The resorption was accompanied by extensive trabecular bone growth and a minimal inflammatory response. Ca- and P-containing granules with an AP-surface layer showed a slower resorption rate and more extensive new bone growth than those without AP layer. Among AP-coated granules, those with incorporated vancomycin showed the most favorable tissue response. The present in vivo data together with prior in vitro data suggest that these xerogels have potential as controlled-release materials for the treatment of bone infections and as carrier materials for a variety of other applications.
AB - Biodegradable, controlled-release carrier materials with non-toxic degradation products are valuable for local delivery of biologically active molecules. Previously, it was shown that room-temperature processed silica sol-gels (or xerogels) are porous, resorbable materials that can release molecules of various sizes in a controlled, time dependent manner. Previous in vitro studies also demonstrated benefits of silica xerogels as controlled-release materials for the treatment of bone infections. Herein the tissue and cell response to xerogels is documented using a subacute implantation procedure. The tissue response was correlated to composition, surface properties, resorption rate and incorporation of the antibiotic vancomycin. Ca- and P-free and Ca- and P-containing xerogels, with and without apatite (AP) surface, were used. Xerogels were implanted either as discs in a subcutaneous site, or as granules in the iliac crest of New Zealand white rabbits. The samples with surrounding tissue were retrieved after 2 and 4 weeks of implantation. Silica xerogels implanted either as discs subcutaneously or as granules in the iliac crest showed a favorable tissue response. The granules, either with or without Ca and P content, gradually resorbed over time. The resorption was accompanied by extensive trabecular bone growth and a minimal inflammatory response. Ca- and P-containing granules with an AP-surface layer showed a slower resorption rate and more extensive new bone growth than those without AP layer. Among AP-coated granules, those with incorporated vancomycin showed the most favorable tissue response. The present in vivo data together with prior in vitro data suggest that these xerogels have potential as controlled-release materials for the treatment of bone infections and as carrier materials for a variety of other applications.
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U2 - 10.1016/j.biomaterials.2004.04.004
DO - 10.1016/j.biomaterials.2004.04.004
M3 - Article
C2 - 15369693
AN - SCOPUS:4444263804
SN - 0142-9612
VL - 26
SP - 1043
EP - 1052
JO - Biomaterials
JF - Biomaterials
IS - 9
ER -