title: Construction of a fluorescent nanostructured chitosan-hydroxyapatite scaffold by nanocrystallon induced biomimetic mineralization and its cell biocompatibility.
abstract: Biomaterial surfaces and their nanostructures can significantly influence cell growth and viability. Thus, manipulating surface characteristics of scaffolds can be a potential strategy to control cell functions for stem cell tissue engineering. In this study, in order to construct a hydroxyapatite (HAp) coated genipin-chitosan conjugation scaffold (HGCCS) with a well-defined HAp nanostructured surface, we have developed a simple and controllable approach that allows construction of a two-level, three-dimensional (3D) networked structure to provide sufficient calcium source and achieve desired mechanical function and mass transport (permeability and diffusion) properties. Using a nontoxic cross-linker (genipin) and a nanocrystallon induced biomimetic mineralization method, we first assembled a layer of HAp network-like nanostructure on a 3D porous chitosan-based framework. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis confirm that the continuous network-like nanostructure on the channel surface of the HGCCS is composed of crystalline HAp. Compressive testing demonstrated that the strength of the HGCCS is apparently enhanced because of the strong cross-linking of genipin and the resulting reinforcement of the HAp nanonetwork. The fluorescence properties of genipin-chitosan conjugation for convenient monitoring of the 3D porous scaffold biodegradability and cell localization in the scaffold was specifically explored using confocal laser scanning microscopy (CLSM). Furthermore, through scanning electron microscope (SEM) observation and immunofluorescence measurements of F-actin, we found that the HAp network-like nanostructure on the surface of the HGCCS can influence the morphology and integrin-mediated cytoskeleton organization of rat bone marrow-derived mesenchymal stem cells (BMSCs). Based on cell proliferation assays, rat BMSCs tend to have higher viability on HGCCS in vitro. The results of this study suggest that the fluorescent two-level 3D nanostructured chitosan-HAp scaffold will be a promising scaffold for bone tissue engineering application.
authors.affiliation: Center of Bio & Micro/nano Functional Materials, State Key Laboratory of Crystal Materials, Shandong University, 27 Shanda Nanlu, Jinan 250100, P.R.China.
authors.forename: Guancong
authors.initials: G
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Zheng
authors.forename: Hongshi
authors.initials: H
authors.lastname: Zhao
authors.forename: Junying
authors.initials: J
authors.lastname: Miao
authors.forename: Chunhui
authors.initials: C
authors.lastname: Sun
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Huang
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Yu
authors.forename: Jiyang
authors.initials: J
authors.lastname: Wang
authors.forename: Xutang
authors.initials: X
authors.lastname: Tao
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000633:toxicity*; D032701:Biomimetics; D002470:Cell Survival; D048271:Chitosan / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D005453:Fluorescence; D059630:Mesenchymal Stem Cells / Q000502:physiology; D036103:Nanotechnology / Q000379:methods*; D051381:Rats; D013194:Staining and Labeling / Q000379:methods; D013499:Surface Properties; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D048271:Chitosan; D017886:Durapatite