Research Article Open Access
Bioprocessing & Biotechniques
Dulinska-Molak, J Bioproces Biotechniq 2014, 4:3
http://dx.doi.org/10.4172/2155-9821.1000153
Volume 4 • Issue 3 • 1000153
J Bioproces Biotechniq
ISSN:2155-9821 JBPBT, an open access journal
*Corresponding author: Ida Dulinska-Molak, Faculty of Materials Science and
Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw, Poland,
Tel: 48-22-6623158; E-mail: ida.dulinska@gmail.com, idad@meil.pw.edu.pl
Received February 26, 2014; Accepted April 11, 2014; Published April 17,
2014
Citation: Dulinska-Molak I, Jaroszewicz J, Kurzydlowski KJ (2014) Architecture
and Properties of PUR/Calcite Composite Scaffolds for Bone Tissue Engineering.
J Bioprocess Biotech 4: 153 doi: 10.4172/2155-9821.1000153
Copyright: © 2014 Dulinska-Molak I, et al. This is an open-access article
distributed under the terms of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided
the original author and source are credited.
Architecture and Properties of PUR/Calcite Composite Scaffolds for Bone
Tissue Engineering
Ida Dulinska-Molak*, Jakub Jaroszewicz and Krzysztof J Kurzydlowski
Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw, Poland
Keywords: PUR/calcite composites; Scafolds; Bioactivity; Porosity;
Microtomography
Introduction
In recent years polymer – bioactive ceramic composite materials
have been developed as bone repair devices because of their high
bioactivity, biocompatibility and biodegradability. Mainly the irst
two properties of tissue engineering scafolds inluence the important
initial steps related to cell attachment, prior to cell proliferation
and diferentiation. An important step to engineer tissues is the
development of porous three-dimensional scafolds for diferent
anatomical locations in the body. Ideally, the scafolds should be
porous and the porosity should be both macroscopic for cell growth
and migration, as well as microscopic to allow the transport of nutrients
and oxygen, as well as the removal of cellular waste products [1]. he
relevant properties of ideal scafolds and the requirements for their
successful application in bone tissue engineering have been extensively
discussed in the literature [2-6]. hey state that scafolds need to be
biocompatible. A three-dimensional (3D) internal geometry, similar
to bone morphology, and the retention of mechanical properties ater
implantation are required for scafolds in order to maintain a tissue
space of prescribed size and shape for tissue formation. Porosity higher
than 70% seems to be necessary. In addition, a macroporosity of 200–
500 µm is needed to promote bone cell attachment, and a microporosity
should promote ion and liquid difusion [7].
Among the polymers selected for clinical and surgical applications,
polyurethanes (PUR) represent a very important group [8]. Segmented
polyurethanes have found application in medicine as biomaterials due
to good biocompatibility and good processability [9]. heir domain
structure allows one to obtain products with a wide range of physical
and mechanical properties. Polyurethanes represent a class of synthetic
elastomers, which physicochemical properties may be modiied
by changing the ratio between sot and hard segments. herefore,
the biodegradable poly (ε-caprolactone) urethane elastomers are
commonly used for production of scafolds in bone tissue engineering
[10-13]. However, the biodegradable polymers in pure form have inite
application, connected mainly with their poor mechanical properties
and insuicient adhesion of cells that is why their usefulness as implants
is limited. he expansion of their application area is connected with
preparation of new materials, polymer-ceramic composites, for tissue
reconstruction, bringing together advantages of single components:
elasticity and strength of polymers with excellent biocompatibility
of ceramics, and developing from the type of tissue, they show
desired proile of degradation, elasticity or hardness. Composite
materials, depending on type of iller used and spatial distribution,
introduce large possibilities of designing both mechanical properties
and biological behavior of such implant, for example adhesion cells
properties. Application of calcium carbonate as a modifying agent
allows stimulating the growth of bone tissue [14-17]. hese materials,
when in contact with the body luids from on their surface a layer of
hydroxyapatite, through with the material used as the implant, forms a
permanent bond with the bone in a living organism [18]. Moreover the
engineered material composed of PUR and calcite supposes to support
a process of creation of a new tissue not only by mechanical properties
but as well by biological response. Based on our previous results [19], in
the present study, was used the calcite powder as a iller.
he morphogenesis of bone in porous bioceramics when implanted
in heterotopic sites was first reported when implanting coral-derived
hydroxyapatite specimens in the rectus abdominal muscle of adult
non-human primates.
A number of methods have been developed to fabricate polymer
scafolds [1]. One of the most common techniques for producing
Abstract
Bone tissue has a composite nature given by a highly complex and well-harmonized structure of organic and
inorganic components on the microscale, macroscale and nanoscale. Thus, biodegradable composite scaffolds made
of poly (ε-caprolactone) urethane (PCL_PUR) porous matrix and calcium carbonate (CaCO
3
) were developed and
studied for bone tissue engineering. The aim of this work was to examine the structure of new polyurethane/calcite
composites. Micro-computer tomography (µ-CT) and image analysis enabled 3D visualization and quantiication
of the porosity, wall thickness and internal pore size distribution. The fabricated porous polyurethane composites
exhibited porosity >70% with a pore size not exceeding 450 µm and wall thickness about of 50 µm in size. The
mechanical properties of the foams were evaluated using Dynamic Mechanical Analysis (DMA). In-vitro bioactivity
tests in simulated body luid (SBF) were carried out and the marker of bioactivity, e.g. formation of surface bone-like
apatite layers upon immersion in SBF, was investigated. Our results indicated that PUR/calcite scaffolds were more
activity then PUR scaffolds and possessed the function to enhance cell proliferation and differentiation, and might be
used as bone tissue engineering materials.