title: Catechol-functionalized adhesive polymer nanoparticles for controlled local release of bone morphogenetic protein-2 from titanium surface.
abstract: We report on a novel surface functionalization approach to equip the titanium (Ti) surfaces with osteogenic properties. A key feature of the approach is the treatment of the Ti surfaces with Ti-adhesive nanoparticles that can stably load and controllably release bone morphogenetic protein-2 (BMP-2). Ti-adhesive nanoparticles were prepared by self-assembly of a catechol-functionalized poly(amino acid) diblock copolymer, catechol-poly(L-aspartic acid)-b-poly(L-phenylalanine) (Cat-PAsp-PPhe). The nanoparticles consist of Ti-adhesive peripheral catechol groups, anionic PAsp shells, and PPhe inner cores. Field-emission scanning electron microscopy (Fe-SEM) images showed that the Ti-adhesive nanoparticles could be uniformly immobilized on Ti surfaces. X-ray photoelectron spectroscopy (XPS) confirmed the successful anchoring of nanoparticles onto Ti surfaces. After surface immobilization of the nanoparticles, the static water contact angle of the Ti substrate decreased from 75.3° to 50.0° or 36.4°, depending on the surface nanoparticle. Fluorescence microscopic analysis showed that BMP-2 could be effectively incorporated onto the Ti surface with adhesive nanoparticles. BMP-2 was controllably released for up to 40 days. The Ti substrate functionalized with BMP-2-incorporated nanoparticles significantly promoted attachment, proliferation, spreading, and alkaline phosphatase (ALP) activity of human adipose-derived stem cell (hADSC). The catechol-functionalized adhesive nanoparticles may be applied to various medical devices to create surfaces for improved performance.
authors.affiliation: Department of Maxillofacial Biomedical Engineering & Institute of Oral Biology, School of Dentistry, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Republic of Korea.
authors.forename: Hong Jae
authors.initials: HJ
authors.lastname: Lee
authors.forename: Ahn Na
authors.initials: AN
authors.lastname: Koo
authors.forename: Suk Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Myung Hyun
authors.initials: MH
authors.lastname: Lee
authors.forename: Sang Cheon
authors.initials: SC
authors.lastname: Lee
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D000273:Adipose Tissue / Q000166:cytology; D000469:Alkaline Phosphatase / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry*; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D003692:Delayed-Action Preparations / Q000737:chemistry; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D013234:Stem Cells / Q000502:physiology; D014025:Titanium / Q000737:chemistry*
chemical_list: D000269:Adhesives; D055396:Bone Morphogenetic Protein 2; D002396:Catechols; D003692:Delayed-Action Preparations; D010455:Peptides; C027751:poly(L-aspartyl-L-phenylalanine); D014025:Titanium; D000469:Alkaline Phosphatase; C034221:catechol
keywords: Adhesive nanoparticle; Bone morphogenetic protein-2; Dental implant; Surface functionalization; Titanium