The effect of electrospun zein nanofiber coated with Nano hydroxyapatite on osteogenic differentiation of mesenchymal stem cells

Background and Aim: Tissue engineering requires comprehensive efforts to combine engineering and physical sciences with life sciences for the purpose of restoring, replacing, or improving the function of damaged tissues and organs. This method is based on three main factors: a scaffold, cells and growth factors. The scaffold, a three-dimensional construct, is designed to support cell infiltration, growth, differentiation, and enhance new tissue development and guide new tissue formation. Among various classes of biomaterials, polymer-based scaffolds are the primary choice for almost all tissues. zein, is a natural polymer isolated from corn which recently regarded as a promising biopolymer for tissue engineering scaffold on account of its amphiphilic nature, nontoxicity, favorable biodegradability and bio-compatibility but like all natural polymers, zein has poor mechanical properties. In order to improve their mechanical properties and water resistance, plant proteins can be blended with inorganic compounds like nano Hydroxyapatite (nHA) that is the main inorganic component of bone.Methods: Zein/nHA nanofibrous structures were fabricated by the electrospinning method. A polymer solution was prepared by dissolving zein in acetic acid. Zein nanofibers coated with Nano hydroxyapatite after fabrication. Surface morphology and pore size of nanocomposite scaffolds were analyzed by images of scanning electron microscope (SEM). Average fiber diameters and Surface pore sizes of nanofibrous scaffolds were determined using ImageJ software. The chemical structure characterized by Fourier transform infrared spectroscopy (FTIR). For invitro assays, the scaffolds cut into small pieces (۱×۱ Cm۲) and sterilized with UV and antibiotics before cells seeding. Human Mesenchymal stem cell was seeded with density of ۵×۱۰۴ cells on Zein Scaffolds. MTT assay was used for cell proliferation assessment after ۴۸h and total RNA was extracted for Osterix and β-catenin genes expression levels in different time period.Results: The diameter of nanofibers was estimated between ۳۳۵-۸۲۸ nm and ۲۹۶-۷۲۲ in nHA coated and control mate respectively. The FTIR spectrum of bulk zein and nanofiber scaffolds had no difference in peaks so no new chemical interaction was suggested and nHA associated to zein nanofibers with physical force. Zein nanofibers in both group had appropriate cell compatibility. The Osterix and β-catenin genes expression elevated significantly in nHA coted zein nanofibers respect with control and zein nanofibers. Conclusion: The electrospun zein nanofiber coated with Nano hydroxyapatite had good effect on osteogenic differentiation of mesenchymal stem cells and may use in bone tissue engineering.

Keywords:

tissue engineering , zein , Nano hydroxyapatite , osteogenic differentiation