title: In vitro and in vivo response to nanotopographically-modified surfaces of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and polycaprolactone.
abstract: Colloidal lithography and embossing master are new techniques of producing nanotopography, which have been recently applied to improve tissue response to biomaterials by modifying the surface topography on a nano-scale dimension. A natural polyester (Biopol), 8% 3-hydroxyvalerate-component (D400G) and a conventional biodegradable polycaprolactone (PCL) were studied, both nanostructured and native forms, in vitro and in vivo. Nanopits (100-nm deep, 120-nm diameter) on the D400G surface were produced by the embossing master technique (Nano-D400G), while nanocylinders (160-nm height, 100-nm diameter) on the PCL surface were made by the colloidal lithography technique (Nano-PCL). L929 fibroblasts were seeded on polyesters, and cell proliferation, cytotoxic effect, synthetic and cytokine production were assessed after 72 h and 7 days. Then, under general anesthesia, 3 Sprague-Dawley rats received dorsal subcutaneous implants of nanostructured and native polyesters. At 1, 4 and 12 weeks the animals were pharmacologically euthanized and implants with surrounding tissue studied histologically and histomorphometrically. In vitro results showed significant differences between D400G and PCL in Interleukin-6 production at 72 h. At 7 days, significant (P < 0.05) differences were found in Interleukin-1beta and tumor necrosis factor-alpha release for Nano-PCL when compared to Nano-D400G, and for PCL in comparison with D400G. In vivo results indicated that Nano-D400G implants produced a greater extent of inflammatory tissue than Nano-PCL at 4 weeks. The highest vascular densities were observed for Nano-PCL at 4 and 12 weeks. Chemical and topographical factors seem to be responsible for the different behaviour, and from the obtained results a prevalence of chemistry on in vitro data and nanotopography on soft tissue response in vivo are hypothesized, although more detailed investigations are necessary in this field.
authors.affiliation: Department of Experimental Surgery, Research Institute 'Codivilla-Putti', Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, I-40136 Bologna, Italy. gianluca.giavaresi@ior.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giavaresi
authors.forename: Matilde
authors.initials: M
authors.lastname: Tschon
authors.forename: John H
authors.initials: JH
authors.lastname: Daly
authors.forename: John J
authors.initials: JJ
authors.lastname: Liggat
authors.forename: Duncan S
authors.initials: DS
authors.lastname: Sutherland
authors.forename: Hossein
authors.initials: H
authors.lastname: Agheli
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.forename: Paola
authors.initials: P
authors.lastname: Torricelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Giardino
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001808:Blood Vessels; D049109:Cell Proliferation; D002470:Cell Survival; D016207:Cytokines / Q000096:biosynthesis; D005347:Fibroblasts / Q000166:cytology; D020007:Implants, Experimental / Q000592:standards*; D007249:Inflammation; D051379:Mice; D018919:Neovascularization, Physiologic; D011091:Polyesters / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D000094122:Polyhydroxybutyrates
chemical_list: D001672:Biocompatible Materials; D016207:Cytokines; D011091:Polyesters; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C016240:polycaprolactone