Fabrication and Analysis of Surface Functionalized Porous PCL-nHA Scaffolds With P(HEMA-co-EGDMA) Hydrogel via iCVD and BMP-2 Release Simulation

Well-designed tissue engineering scaffolds are needed for effective healing by regulating cell behavior such as cell attachment, proliferation and differentiation. Scaffolds should not only exhibit biocompatibility, interconnected porosity and strength but should provide hydrophilic surface where cell adheres in-vitro and in-vivo. The aim of this study is the fabrication and characterization of porous and surface functionalized biocompatible scaffolds for bone tissue engineering. Few studies exist in literature using iCVD for surface functionalization of bone scaffolds. For instance, p(HEMA-co-EDGMA) microbeads were synthesized by suspension polymerization technique by Ayhan et al. [1]. showing that 3T3 and MDBK cell lines significantly attached on these microbeads. Bose et al. [2] fabricated p(HEMA) thin film via iCVD and demonstrated that thin films were nontoxic and have good adhesive property for fibroblast cells. p(HEMA) was produced by thermally initiated free radical polymerization by Passos et al. [3] demonstrating biocompatibility of p(HEMA) without showing apoptosis. Giglio et al. [4] used electro-polymerization technique to produce p(HEMA) based thin films coated with p(HEMA) increasing cell attachment. Ma et al. [5] showed that PCL electrospun substrate can be coated with iCVD. Cheng et al. [7] studied the response of 3D printed scaffolds coated with p(HEMA-co-EGDMA) via iCVD and they achieved hydrophilic surface. Contact angle measurement of the study of Gupta et al. [7] demonstrated that surface properties of pores was tuned by iCVD nanocoating.  In this study, we will produce porous PCL-nHA scaffolds using earlier proposed NIPS (acik hali) with multi-scale porosity and use iCVD for coating these scaffolds with p(HEMA-co-EGDMA) polymer. The goal is to explore the increased biofunctionality using MT3T3-e1 cells on iCVD coated scaffolds fabricated using NIPS. Porosity analysis was performed by micro-CT and SEM showed that scaffolds exhibited highly porous structure both internally and on the surface. Surface characterization was performed via FTIR, AFM and X-ray Photoelectron Spectroscopy to show coating was successfully achieved. Contact angle measurement was performed to demonstrate hydrophilic surface was obtained after iCVD coating. In-vitro analyses were carried out to show enhancement of cell activities on scaffolds. The study demonstrated that surface modified PCL-nHA scaffolds with p(HEMA-co-EGDMA) hydrogel exhibited augmented compatibility with cell media by enhancing cell attachment, proliferation and differentiation in vitro.

References:

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