IOP PUBLISHING BIOMEDICAL MATERIALS
Biomed. Mater. 7 (2012) 015001 (16pp) doi:10.1088/1748-6041/7/1/015001
Biomimetic surface modification of
titanium surfaces for early cell capture by
advanced electrospinning
Rajeswari Ravichandran
1,2,3
, Clarisse CH Ng
4
, Susan Liao
5, 8
,
Damian Pliszka
2
, Michael Raghunath
1,6
, S Ramakrishna
2,3
and
Casey K Chan
1,7
1
Division of Bioengineering, Faculty of Engineering, National University of Singapore,
Singapore 117574
2
Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3,
Singapore 117576
3
Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore,
Singapore 117576
4
Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore,
11 Lower Kent Ridge Road, Singapore 119083
5
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
6
Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore,
8 Medical Drive, Singapore 117597
7
Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine,
National University of Singapore, Singapore 119074
E-mail: SusanLiao@ntu.edu.sg
Received 17 June 2011
Accepted for publication 21 November 2011
Published 9 December 2011
Online at stacks.iop.org/BMM/7/015001
Abstract
The time required for osseointegration with a metal implant having a smooth surface ranges
from three to six months. We hypothesized that biomimetic coating surfaces with
poly(lactic-co-glycolic acid) (PLGA)/collagen fibers and nano-hydroxyapatite (n-HA) on the
implant would enhance the adhesion of mesenchymal stem cells. Therefore, this surface
modification of dental and bone implants might enhance the process of osseointegration. In
this study, we coated PLGA or PLGA/collagen (50:50 w/w ratio) fiber on Ti disks by
modified electrospinning for 5 s to 2 min; after that, we further deposited n-HA on the fibers.
PLGA fibers of fiber diameter 0.957 ± 0.357 μm had a contact angle of 9.9 ± 0.3
◦
and
PLGA/collagen fibers of fiber diameter 0.378 ± 0.068 μm had a contact angle of 0
◦
. Upon
n-HA incorporation, all the fibers had a contact angle of 0
◦
owing to the hydrophilic nature of
n-HA biomolecule. The cell attachment efficiency was tested on all the scaffolds for different
intervals of time (10, 20, 30 and 60 min). The alkaline phosphatase activity, cell proliferation
and mineralization were analyzed on all the implant surfaces on days 7, 14 and 21. Results of
the cell adhesion study indicated that the cell adhesion was maximum on the implant surface
coated with PLGA/collagen fibers deposited with n-HA compared to the other scaffolds.
Within a short span of 60 min, 75% of the cells adhered onto the mineralized PLGA/collagen
fibers. Similarly by day 21, the rate of cell proliferation was significantly higher (p 0.05) on
the mineralized PLGA/collagen fibers owing to enhanced cell adhesion on these fibers. This
enhanced initial cell adhesion favored higher cell proliferation, differentiation and
mineralization on the implant surface coated with mineralized PLGA/collagen fibers.
S Online supplementary data available from stacks.iop.org/BMM/7/015001/mmedia
(Some figures in this article are in colour only in the electronic version)
8
Author to whom any correspondence should be addressed.
1748-6041/12/015001+16$33.00 1 © 2012 IOP Publishing Ltd Printed in the UK