title: Long- and short-term effects of biological hydrogels on capsule microvascular density around implants in rats.
abstract: Fibrous capsule formation around implants can inhibit solute exchange between implantable devices and the circulation. Parylene-n coated polycarbonate disks surrounded with growth factor reduced Matrigel (MG) or several gelatin-based matrices were implanted intramuscularly into rats for 21 or 50 days. MG supplemented with vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) increased capsule microvascular density at 21 days (p < 0.05) when compared to bare parylene-coated polycarbonate disks (control). The increased microvascular density around VEGF- and bFGF-treated implants regressed by 50 days and was no longer significantly different from controls. The microvascular density induced by the gelatin-based matrices was not significantly different from controls at 21 days, but was increased at 50 days (p < 0.05), suggesting a slower, long-term effect. Disks treated with MG and gelatin-based matrices had thinner capsules at 21 days (p < 0.05). By 50 days, the capsule thicknesses around these implants were no longer statistically thinner than controls. The capsule thickness around implants treated with VEGF, bFGF, and essential gelatin-based matrix was thinner than controls at 50 days (p < 0.05). These results indicate that it is possible to increase functional microvascular density within fibrous capsules using angiogenic growth factors and gelatin-based matrices. However, this effect may be short-lived, requiring chronic administration of growth factors.
authors.affiliation: Kenan Plastic Surgery Research Laboratories, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Ravin
authors.forename: K C
authors.initials: KC
authors.lastname: Olbrich
authors.forename: L S
authors.initials: LS
authors.lastname: Levin
authors.forename: A L
authors.initials: AL
authors.lastname: Usala
authors.forename: B
authors.initials: B
authors.lastname: Klitzman
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D016228:Endothelial Growth Factors / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005549:Foreign-Body Reaction / Q000473:pathology; D020100:Hydrogels / Q000494:pharmacology*; D008222:Lymphokines / Q000494:pharmacology; D008297:Male; D008422:Materials Testing; D008833:Microcirculation / Q000187:drug effects / Q000473:pathology; D019736:Prostheses and Implants / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D001672:Biocompatible Materials; D016228:Endothelial Growth Factors; D020100:Hydrogels; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2