Fabrication and Cellular Investigation of Biomimetic Collagen-Gelatin Nanopillar Films

Introduction One of the common problems in implant dentistry is the lack of sufficient amount of bone tissue formation around the implant.  Investigation of bone and teeth interaction brings out the periodontal... [ view full abstract ]

• Introduction

One of the common problems in implant dentistry is the lack of sufficient amount of bone tissue formation around the implant.  Investigation of bone and teeth interaction brings out the periodontal ligament (PDL), which provides bone regeneration. Some parts of PDL include Sharpey fibers and it consists of structures linking teeth and bone. These fibers are generally positioned parallel to each other and perpendicular to the tooth surface. Besides , they have extremely rich and regular structure of collagen. Our aim in this study is to examine bone cell behaviors on arrays of collagen-gelatin mixed nanorods which are bioinspired from Sharpey fiber structures and compare them to flat collagen-gelatin films. Such nanorod arrays were fabricated using anodic aluminum oxide (AAO) molds. These nanoporous substrates are ideal molds for many applications owing to their modifiable chemistry, ultrahigh surface areas, and controllable porosity and pore dimensions that extend perpendicular to membrane surface. 

• Methods

In this study, we fabricated nanoporous AAO molds by the two-step anodization of ultrapure Al foils and decreased their surface energy by using silane chemistry. Different concentrations of collagen-gelatin solution were used to obtain collagen-gelatin films that replicate the topography of the AAO molds. We have optimized the PEGDGE concentration in the collagen-gelatin solution to obtain stable nanostructures. The morphological characterization of these nanorod arrays were examined by using scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig.1). Their stability tests in water and cell medium were conducted by utilizing SEM imaging and swelling tests. Also, cell viability and toxicity tests on SAOS-2 cells were completed.

• Results & Discussion

Improved cell adhesion and viability were observed on the nanorod collagen-gelatin films compared to flat collagen-gelatin films. Also, collagen-gelatin films were not toxic to the cells.  Finally,mineralization and ALP activity of SAOS-2 cells on nanostructured surfaces will be completed and compared to flat collagen-gelatin films.

The project is partially supported by Turkish Academy of Science (TUBA).