title: Effect of well defined dodecahedral porosity on inflammation and angiogenesis.
abstract: Porosity is an important factor in the healing of prosthetic devices. To better understand this phenomenon, porous polyurethane scaffolds were produced by a variation of the phase inversion/porogen extraction technique in which a prepacked column of spherical porogen particles was infiltrated with a polymer solution before polymer precipitation and porogen extraction. Scaffolds contained pores of well defined shape (approaching open faced pentagonal dodecahedra), narrow size distributions (66.1 +/- 1.3 microm, 84.2 +/- 1.7 microm, and 156.9 +/- 1.2 microm) and high interconnectivity (interconnecting windows of 30.1 +/- 0.8 microm, 41.9 +/- 1.5 microm, and 76.4 +/- 2.0 microm, respectively). A high degree of accessible macroporosity (>80%) could be achieved while limiting the mostly inaccessible microporosity to below 2%. The neovascularization and inflammatory responses to the scaffolds were evaluated in the subcutaneous rat model for 4 weeks. The inflammatory response index and foreign body giant cell index could be reduced by 56% (p < 0.05) and 21% (p < 0.02), respectively, when the pore size was increased from 66 microm to 157 microm, whereas the vascularization index and arteriolar index remained unchanged. Thus, a significant decrease in inflammatory response could be achieved without adversely affecting the degree of neovascularization by increasing the size of the pores.
authors.affiliation: Cardiovascular Research Unit, Cape Heart Centre, University of Cape Town Medical School, South Africa.
authors.forename: Deon
authors.initials: D
authors.lastname: Bezuidenhout
authors.forename: Neil
authors.initials: N
authors.lastname: Davies
authors.forename: Peter
authors.initials: P
authors.lastname: Zilla
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D005208:Fasciitis / Q000139:chemically induced*; D005547:Foreign Bodies / Q000276:immunology; D008297:Male; D008956:Models, Chemical; D018919:Neovascularization, Physiologic; D011140:Polyurethanes / Q000737:chemistry / Q000494:pharmacology*; D019736:Prostheses and Implants / Q000009:adverse effects; D051381:Rats; D017208:Rats, Wistar; D040521:Subcutaneous Tissue / Q000276:immunology*; D014945:Wound Healing / Q000276:immunology
chemical_list: D001672:Biocompatible Materials; D011140:Polyurethanes