LBL coating of type I collagen and hyaluronic acid on aminolyzed PLLA to enhance the cell-material interaction

Abstract

The aim of the present work is to assemble extracellular matrix components onto poly (L-lactic acid) (PLLA) films using layer-by-layer (LBL) depositing method to enhance the cell-material interaction. To introduce charges onto the hydrophobic and neutral PLLA surface so that the electronic assembly can be processed, poly (ethylene imine) (PEI) was covalently bonded to modify the PLLA films. Positively charged collagen I (Col I) was then deposited onto the aminolyzed PLLA film surface in a LBL assembly manner using hyaluronic acid (HA) as a negatively charged polyelectrolyte. The PEI modification efficiency was monitored via X-ray photoelectron spectroscopy (XPS) measurements. The results of Surface Plasmon Resonance (SPR) and Water contact angle (WCA) monitoring the LBL assemble process presented that the HA/Col I deposited alternately onto the PLLA surface. The surface topography of the films was observed by Atomic force microscope (AFM). In vitro osteoblast culture found that the presence of Col I layer greatly improved the cytocompatibility of the PLLA films in terms of cell viability, cell proliferation and Alkaline Phosphatase (ALP) expression. Furthermore, osteoblast extensions were found to be directed by contact guidance of the aligned Col I fibrils. Thus, these very flexible systems may allow broad applications for improve the bioactivity of polymeric materials, which might be a potential application for bone tissue engineering.

Keywords

• Biocompatible polymers
• Layer by layer
• type I collagen
• Hyaluronic acid
• Osteoblast