Biomimetic mineralization of carboxymethyl chitosan nanofibers with improved osteogenic activity in vitro and in vivo. (1st September 2018)

• Record Type: Journal Article
• Authors: Zhao, Xiujuan; Zhou, Liangyu; Li, Qingtao; Zou, Qingxia; Du, Chang
• Is Part Of: Carbohydrate polymers. Volume 195(2018)
• Page Start: 225
• Page End: 234
• Publication Date: 2018-09-01
• Subjects: Carboxymethyl chitosan -- Hydroxyapatite -- Nanofibers -- Osteogenic differentiation; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2018.04.090
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Water-soluble uniform CMCS nanofibers were electrospun with the aid of PEO. CMCS nanofibers enhanced the mineralization due to the introduction of −COOH. CMCS-HA nanofibers promoted the osteogenesis both in vitro and in vivo. Abstract: Inspired by the natural extracellular matrix, the organic-inorganic composite nanofibers are promising scaffolds for bone tissue engineering. Chitosan-based nanofibers are widely used as bone tissue engineering scaffolds with good biocompatibility but pungent solvents are frequently used for its processing. Carboxymethyl chitosan (CMCS), a water-soluble derivative of chitosan, has better biodegradability and bioactivity which allows CMCS to chelate Ca 2+ and induce the deposition of apatite. Moreover, with water as solvent, CMCS nanofibers avoid the acidic salt removal comparing to electrospun-chitosan. In this study, we successfully prepared uniform CMCS nanofibers with the aid of polyethylene oxide (PEO) and obtained the optimized conditions with a voltage of 25 kV and PEO of molecular weight 1000 kDa. We further prepared hydroxyapatite (HA) coated electrospun CMCS nanofibers by biomimetic mineralization using 5 times simulated body fluid. The promotion of osteogenic differentiation of mouse bone marrow stromal cells (mBMSCs) in vitro was evaluated on the nanofibers scaffolds. Cell experiments revealed that CMCS-HA composite nanofibers increased the ALP activity. The gene expression level of Runx2 and ALP were about 1.6 and 4.3 folds at the 7 days, and 5.1 and 10 folds at the 14 days on CMCS-HA nanofibrous membranes than that on CMCS alone samples. The level of OCN increased by 24 and 1.5 times on the CMCS-HA scaffolds than CMCS scaffolds at the 14 and 21 days. In vivo new bone formation by nanofiber scaffolds was investigated in a critical-size rat calvarial bone defect model. Micro-CT results showed that the whole defect was covered by new bone after CMCS-HA filling the defect for 12 weeks. The results of H&E staining and Masson's trichrome staining on histological sections further confirmed that composite nanofibers promoted new bone formation and maturation.