title: Development and characterization of rhVEGF-loaded poly(HEMA-MOEP) coatings electrosynthesized on titanium to enhance bone mineralization and angiogenesis.
abstract: Osteointegration of titanium implants could be significantly improved by coatings capable of promoting both mineralization and angiogenesis. In the present study, a copolymeric hydrogel coating, poly-2-hydroxyethyl methacrylate-2-methacryloyloxyethyl phosphate (P(HEMA-MOEP)), devised to enhance calcification in body fluids and to entrap and release growth factors, was electrosynthesized for the first time on titanium substrates and compared to poly-2-hydroxyethyl methacrylate (PHEMA), used as a blank reference. Polymers exhibiting negatively charged groups, such as P(HEMA-MOEP), help to enhance implant calcification. The electrosynthesized coatings were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. MG-63 human osteoblast-like cell behaviour on the coated specimens was investigated by scanning electron microscopy, MTT viability test and osteocalcin mRNA detection. The ability of negatively charged phosphate groups to promote hydroxyapatite-like calcium phosphate deposition on the implants was explored by immersing them in simulated body fluid. Similar biological responses were observed in both coated specimens, while calcium-phosphorus globules were detected only on P(HEMA-MOEP) surfaces pretreated with alkaline solution. Testing of the ability of P(HEMA-MOEP) hydrogels to entrap and release human recombinant vascular endothelial growth factor, to tackle the problem of insufficient oxygen and nutrient delivery, suggested that P(HEMA-MOEP)-coated titanium prostheses could represent a multifunctional material suitable for bone restoration applications.
authors.affiliation: Department of Chemistry, University of Bari, Bari, Italy. e.degiglio@chimica.uniba.it
authors.forename: Elvira
authors.initials: E
authors.lastname: De Giglio
authors.forename: Stefania
authors.initials: S
authors.lastname: Cometa
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Ricci
authors.forename: Antonio
authors.initials: A
authors.lastname: Zizzi
authors.forename: Damiana
authors.initials: D
authors.lastname: Cafagna
authors.forename: Sandra
authors.initials: S
authors.lastname: Manzotti
authors.forename: Luigia
authors.initials: L
authors.lastname: Sabbatini
authors.forename: Monica
authors.initials: M
authors.lastname: Mattioli-Belmonte
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002113:Calcification, Physiologic / Q000187:drug effects*; D002118:Calcium / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival; D006801:Humans; D008689:Methacrylates / Q000737:chemistry*; D018919:Neovascularization, Physiologic; D010006:Osteoblasts / Q000378:metabolism; D010758:Phosphorus / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014025:Titanium / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D008689:Methacrylates; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D042461:Vascular Endothelial Growth Factor A; D010758:Phosphorus; C026575:2-hydroxyethyl methacrylate phosphate; C005044:hydroxyethyl methacrylate; D014025:Titanium; C022616:thiazolyl blue; D002118:Calcium