Stem Cell Based Tissue-Engineered Grafts for
Articular Cartilage Defects- a Mini Review Volume 5 - Issue 3
Amit Kumar Singh and Krishna Pramanik*
Center of Excellent in Tissue Engineering, Department of Biotechnology & Medical Engineering, National Institute of Technology, India
Received: May 31, 2018; Published: June 13, 2018
*Corresponding author: Krishna Pramanik, Center of Excellent in Tissue Engineering, Department of Biotechnology & Medical Engineering, National
Institute of Technology, Rourkela, India
Millions of patient report hospital with joint and articular
cartilage injuries that are usually occur in knee, wrist, and ankle
joints. Among these, knee injury is the most critical and common
one. People also suffer from knee arthritis which is caused by
progressive cartilage tissue loss due to wear and tear [1]. Among
the different joints affected by osteoarthritis, knee arthritis is the
most critical that resists patients from doing everyday activities
[2]. In osteoarthritis, the cartilage in the knee joint gradually
wears away which further exposes the bony ends thereby affecting
subchondral bone site of the knee and ultimately produces painful
bone spurs [3]. Articular cartilage defects are difficult to heal due to
their avascular nature and the repair process is only transient and
imperfect, and tissue degeneration eventually occurs leading to the
progressive deposition of subchondral bone [4,5]. Osteochondral
lesion involving both articular cartilage surface and underlying
subchondral bone, essentially forms fibrocartilage and loose its
ability to protect subchondral bone degeneration [6]. All these
events lead to severe pain, joint deformity, and retardation of joint
mobility.
More than 51 million peoples had been reported to visit
hospitals with some form of arthritis in USA only [7,8]. The currently
used mosaicplasty, autologous chondrocytes transplantation and
marrow stimulation techniques for the treatment of damaged
cartilage and subchondral bone tissue often offer unsatisfactory
outcome eventually lead to the continuing of pain [9,10]. The
recently emerged tissue engineering technique has brought a
new hope to the patients providing a suitable strategy for the
regeneration and repairing of the damaged tissues through
developing biologically functionalized scaffolds derived from
biomaterials with appropriate properties mimicking body tissue
[11-13]. However, it is quite obvious that TE, being new have
numerous challenges starting with its development to actual
application in human health care. The success of TE depends on
various factors that often relate to patient’s defect site, properties
of scaffold acts as a platform for cell career, cell types for neo tissue
generation and level of interaction between scaffold and native
body tissue [12,13]. The tissue-engineered scaffold developed
from biodegradable and biocompatible polymers combined with
bioactive ceramics are proven to be promising, however, the success
of these techniques largely determined by the fabrication methods,
cell source and signaling factors [14-17].
Though electrospinning has been evolved as the suitable
fabrication technique [18] and being widely used so far, rapid
prototyping technique, bioprinting in particular, is considered
as the most appropriate which needs further development for
its commercial availability with affordable cost [19]. Another
important factor for the success of TE is to develop cartilage–
bone interfaces that should be intact after implantation. Novel
strategies suggest the fabrication of scaffolds with distinct layers of
different biomaterials [20,21]. Stem cells, specifically mesenchymal
stem cells possessing excellent chondrogenic and osteogenic
differentiation capability are attractive cell source. Suitable cell
signaling factors such as specific growth factors, mechanical and
electrical stimulation and gas exchange are important to trigger and
regulate cell differentiation and to improve mechanical property of
the cartilage tissue after implantation [22].
The repair of osteochondral tissue defect involves much
critical challenges as it is often associated with the risk of changes
in cell phenotype and structural de-organization of the native
tissue by the regeneration of neo-cartilage tissue [23-24]. It is,
therefore, important to assure the ability of the scaffolds towards
tissue integration through in vivo study using animal model with
variation in defect thickness, angiogenesis, inflammatory effect and
long-term stability to translate in-vitro data into clinically relevant
approaches. To simulate in vitro tissue formation at optimal level,
a suitable bioreactor system and its scale up are important. In this
context, perfusion bioreactor is efficient that provides dynamic
culture system resulting in the homogeneous cell distribution throughout the scaffold and offers better nutrient exchange [25-
27]. The preservation of the tissue engineered grafts on long-term
perspective is important for commercialization of these products
[28].
ISSN: 2574 -1241
Abstract
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