Logo image
Gene Activated Titanium Surfaces Promote In Vitro Osteogenesis
Journal article   Peer reviewed

Gene Activated Titanium Surfaces Promote In Vitro Osteogenesis

Keerthi Atluri, Joun Lee, Denise Seabold, Satheesh Elangovan and Aliasger K Salem
The International journal of oral & maxillofacial implants, Vol.32(2), pp.e83–e96-e83–e96
2017
DOI: 10.11607/jomi.5026
PMCID: PMC5350041
PMID: 27706263
url
http://doi.org/10.11607/jomi.5026View
Open Access

Abstract

Commercially pure titanium (CpTi) and its alloys possess favorable mechanical and biological properties for use as implants in orthopedics and dentistry. However, failures in osseointegration still exist and are common in select individuals with risk factors such as smoking. Therefore, in this study, a proposal was made to enhance the potential of CpTi discs for osseointegration by coating their surfaces with nanoplexes comprising polyethyleneimine (PEI) and plasmid DNA encoding bone morphogenetic protein-2 ( pBMP-2 ). The nanoplexes were characterized for size and surface charge at a range of N/P ratios. CpTi discs were surface characterized for morphology and composition before and after nanoplex coating using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD). The cytotoxicity and transfection ability of CpTi discs coated with nanoplexes of varying N/P ratios in human bone marrow derived mesenchymal stem cells (BMSCs) was measured via MTS assays and flow cytometry, respectively. The CpTi discs coated with nanoplexes prepared at an N/P ratio of 10 (N/P-10) were considered optimal, resulting in 75% cell viability and 14% transfection efficiency. ELISA results demonstrated a significant enhancement in BMP-2 protein secretion by BMSCs 7 days post-treatment with CpTi discs coated with PEI/ pBMP-2 nanoplexes (N/P-10), compared to the controls. Real time PCR data demonstrated that the BMSCs treated with PEI/ pBMP-2 nanoplex coated CpTi discs resulted in an enhancement of runx-2 , alkaline phosphatase and osteocalcin gene expressions on day 7, post-treatment. In addition, these BMSCs demonstrated enhanced calcium deposition on day 30 post-treatment as determined by qualitative (alizarin red staining) and quantitative (atomic absorption spectroscopy) assays. Thus, from all the above data it can be concluded that PEI/ pBMP-2 nanoplex (N/P-10) coated CpTi discs have the potential to induce osteogenesis and enhance osseointegration.
Titanium gene therapy non-viral BMP-2 implant surface

Details

Metrics

Logo image