title: Amide-linkage formed between ammonia plasma treated poly(D,L-lactide acid) scaffolds and bio-peptides: enhancement of cell adhesion and osteogenic differentiation in vitro.
abstract: The surface characteristics of scaffolds for bone tissue engineering must support cell adhesion, migration, proliferation, and osteogenic differentiation. In the study, poly(D,L-lactide acid) (PDLLA) scaffolds were modified by combing ammonia (NH(3) ) plasma pretreatment with Gly-Arg-Gly-Asp-Ser (GRGDS)-peptides coupling technologies. The x-ray photoelectron spectroscopy (XPS) survey spectra showed the peak of N1s at the surface of NH(3) plasma pretreated PDLLA, which was further raised after GRGDS conjugation. Furthermore, N1s and C1s in the high-resolution XPS spectra revealed the presence of -C=N(imine), -C-NH-(amine), and -C=O-NH- (amide) groups. The GRGDS conjugation increased amide groups and decreased amine groups in the plasma-treated PDLLA. Confocal microscope and high performance liquid chromatography verified the anchored peptides after the conjugation process. Bone marrow mesenchymal stem cells were co-cultured with scaffolds. Fluorescent microscope and scanning electron microscope photographs revealed the best cell adhesion in NH(3) plasma pretreated and GRGDS conjugated scaffolds, and the least attachment in unmodified scaffolds. Real-time PCR demonstrated that expression of osteogenesis-related genes, such as osteocalcin, alkaline phosphatase, type I collagen, bone morphogenetic protein-2 and osteopontin, was upregulated in the single NH(3) plasma treated and NH(3) plasma pretreated scaffolds following GRGDS conjugation. The results show that NH(3) plasma treatment promotes the conjugation of GRGDS peptides to the PDLLA scaffolds via the formation of amide linkage, and combination of NH(3) plasma treatment and peptides conjugation may enhance the cell adhesion and osteogenic differentiation in the PDLLA scaffolds. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 682-694, 2011.
authors.affiliation: Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Zi-Xing
authors.initials: ZX
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Zhao-Ming
authors.initials: ZM
authors.lastname: Zhong
authors.forename: Ding-Sheng
authors.initials: DS
authors.lastname: Zha
authors.forename: Song-Hui
authors.initials: SH
authors.lastname: Wu
authors.forename: Fu-Qiang
authors.initials: FQ
authors.lastname: Liu
authors.forename: Wen-De
authors.initials: WD
authors.lastname: Xiao
authors.forename: Xiao-Rui
authors.initials: XR
authors.lastname: Jiang
authors.forename: Xin-Xin
authors.initials: XX
authors.lastname: Zhang
authors.forename: Jian-Ting
authors.initials: JT
authors.lastname: Chen
mesh_terms: D000577:Amides / Q000737:chemistry; D000641:Ammonia; D000818:Animals; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D015870:Gene Expression; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology; D009842:Oligopeptides / Q000737:chemistry; D010012:Osteogenesis / Q000235:genetics; D011091:Polyesters / Q000737:chemistry; D051381:Rats; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000577:Amides; D009842:Oligopeptides; D011091:Polyesters; C033616:poly(lactide); D000641:Ammonia; C049554:glycyl-arginyl-glycyl-aspartyl-serine