Repair of full-thickness tendon injury using connective tissue progenitors efficiently derived from human embryonic stem cells and fetal tissues.
ABSTRACT The use of stem cells for tissue engineering (TE) encourages scientists to design new platforms in the field of regenerative and reconstructive medicine. Human embryonic stem cells (hESC) have been proposed to be an important cell source for cell-based TE applications as well as an exciting tool for investigating the fundamentals of human development. Here, we describe the efficient derivation of connective tissue progenitors (CTPs) from hESC lines and fetal tissues. The CTPs were significantly expanded and induced to generate tendon tissues in vitro, with ultrastructural characteristics and biomechanical properties typical of mature tendons. We describe a simple method for engineering tendon grafts that can successfully repair injured Achilles tendons and restore the ankle joint extension movement in mice. We also show the CTP's ability to differentiate into bone, cartilage, and fat both in vitro and in vivo. This study offers evidence for the possibility of using stem cell-derived engineered grafts to replace missing tissues, and sets a basic platform for future cell-based TE applications in the fields of orthopedics and reconstructive surgery.
- SourceAvailable from: europepmc.org[show abstract] [hide abstract]
ABSTRACT: Stem cells are one of the most fascinating areas in regenerative medicine today. They play a crucial role in development and regeneration and are defined as cells that continuously reproduce themselves while maintaining the ability to differentiate into various cell types. Stem cells are found at all developmental stages, from embryonic stem cells (ESCs) which differentiate into all cell types, to adult stem cells (ASCs) which are responsible for tissue regeneration. Studies using animal models have shown promising results following cell therapy for induced injury in musculoskeletal system, including tendon healing, but the results can be variable. Alternative sources for cell therapy in tendon pathology may include ESCs, ASCs (bone marrow, adipose tissue or tendon derived stem cells) or induced pluripotent stem cells (iPSCs). While ethical and safety concerns currently forbid clinical application of ESCs and iPSCs, initial clinical trials with ASCs are promising.Muscles, ligaments and tendons journal. 07/2012; 2(3):204-11.
- [show abstract] [hide abstract]
ABSTRACT: Treatment of soft and hard connective tissues especially those associated with massive tissue loss is technically demanding. Tendon and cartilage have low healing capability. Massive bone injures are often associated with non-union or malunion and other complications. Treatment of tendon-bone junction is challenging and treatment of osteoarthritis is more palliative than curative. Tissue engineering which composed of three elements including scaffolds, healing promotive factors such as growth factors, and stem cells is an option. Recently stem cell based therapy is much popular due to the encouraging reported results. This review introduced stem cells and discussed their potential application and roles in tissue regenerative medicine. We have focused on the effectiveness of stem cells based therapy on different tissue injuries, including tendon, tendon to bone junction, bone, cartilage and osteoarthritis. In vitro to clinical evidences have been discussed in detail with the aiming to conclude whether stem cell based therapy is a clinically accepted method. This review showed that despite of exploring several sources for the stem cells, the adult mesenchymal stem cells are still the only reliable stem cells in tissue regenerative medicine. In addition, despite of significant improvement in tissue engineering, it seems cell seeding is technically demanding and direct injection of the stem cells is the only reliable method for cell delivery at injured site. Because of controversial results and lack of well-designed clinical trial studies, this review also showed that despite of several animal studies and application of stem cells on various tissue injuries, it is still soon to suggest stem cell therapy as an effective method in restoring morphology and functionality of the injured tissues.Hard Tissue. 05/2013; 2(4):31.
- [show abstract] [hide abstract]
ABSTRACT: Engineering strategies guided by developmental biology may enhance and accelerate in vitro tissue formation for tissue engineering and regenerative medicine applications. In this study, we looked toward embryonic tendon development as a model system to guide our soft tissue engineering approach. To direct cellular self-assembly, we utilized laser micromachined, differentially adherent growth channels lined with fibronectin. The micromachined growth channels directed human dermal fibroblast cells to form single cellular fibers, without the need for a provisional three-dimensional extracellular matrix or scaffold to establish a fiber structure. Therefore, the resulting tissue structure and mechanical characteristics were determined solely by the cells. Due to the self-assembly nature of this approach, the growing fibers exhibit some key aspects of embryonic tendon development, such as high cellularity, the rapid formation (within 24 h) of a highly organized and aligned cellular structure, and the expression of cadherin-11 (indicating direct cell-to-cell adhesions). To provide a dynamic mechanical environment, we have also developed and characterized a method to apply precise cyclic tensile strain to the cellular fibers as they develop. After an initial period of cellular fiber formation (24 h postseeding), cyclic strain was applied for 48 h, in 8-h intervals, with tensile strain increasing from 0.7% to 1.0%, and at a frequency of 0.5 Hz. Dynamic loading dramatically increased cellular fiber mechanical properties with a nearly twofold increase in both the linear region stiffness and maximum load at failure, thereby demonstrating a mechanism for enhancing cellular fiber formation and mechanical properties. Tissue engineering strategies, designed to capture key aspects of embryonic development, may provide unique insight into accelerated maturation of engineered replacement tissue, and offer significant advances for regenerative medicine applications in tendon, ligament, and other fibrous soft tissues.Tissue Engineering Part A 01/2013; · 4.64 Impact Factor
Tissue Eng Part A. 2010 Oct;16(10):3119-37.
Repair of full-thickness tendon injury using connective tissue progenitors efficiently
derived from human embryonic stem cells and fetal tissues.
Cohen S, Leshansky L, Zussman E, Burman M, Srouji S, Livne E, Abramov N, Itskovitz-
Sohnis and Forman Families Center for Stem Cell and Tissue Regeneration Research,
Faculty of Medicine, Technion, Haifa, Israel.
The use of stem cells for tissue engineering (TE) encourages scientists to design new
platforms in the field of regenerative and reconstructive medicine. Human embryonic stem
cells (hESC) have been proposed to be an important cell source for cell-based TE
applications as well as an exciting tool for investigating the fundamentals of human
development. Here, we describe the efficient derivation of connective tissue progenitors
(CTPs) from hESC lines and fetal tissues. The CTPs were significantly expanded and
induced to generate tendon tissues in vitro, with ultrastructural characteristics and
biomechanical properties typical of mature tendons. We describe a simple method for
engineering tendon grafts that can successfully repair injured Achilles tendons and
restore the ankle joint extension movement in mice. We also show the CTP's ability to
differentiate into bone, cartilage, and fat both in vitro and in vivo. This study offers
evidence for the possibility of using stem cell-derived engineered grafts to replace
missing tissues, and sets a basic platform for future cell-based TE applications in the
fields of orthopedics and reconstructive surgery.
PMID: 20486794 [PubMed - in process]
Int J Clin Exp Med. 2010 Sep 7;3(4):248-69.
Bone marrow and umbilical cord blood human mesenchymal stem cells: state of the art.
Malgieri A, Kantzari E, Patrizi MP, Gambardella S.
Mesenchymal stem cells (MSCs) are multipotent adult stem cells present in all tissues, as
part of the perivascular population. As multipotent cells, MSCs can differentiate into
different tissues originating from mesoderm ranging from bone and cartilage, to cardiac
muscle. MSCs are an excellent candidate for cell therapy because they are easily
accessible, their isolation is straightforward, they can be bio-preserved with minimal loss
of potency, and they have shown no adverse reactions to allogeneic versus autologous
MSCs transplants. Therefore, MSCs are being explored to regenerate damaged tissue and
treat inflammation, resulting from cardiovascular disease and myo-cardial infarction (MI),
brain and spinal cord injury, stroke, diabetes, cartilage and bone injury, Crohn's disease
and graft versus host disease (GvHD). Most of the application and clinical trials involve
MSCs from bone marrow (BMMSCs). Transplantation of MSCs from bone marrow is
considered safe and has been widely tested in clinical trials of cardiovascular,
neurological, and immunological disease with encouraging results. There are examples of
MSCs utilization in the repair of kidney, muscle and lung. The cells were also found to
promote angiogenesis, and were used in chronic skin wound treatment. Recent studies
involve also mesenchymal stem cell transplant from umbilical cord (UCMSCt). One of
these demonstrate that UCMSCt may improve symptoms and biochemical values in
patients with severe refractory systemic lupus erythematosus (SLE), and therefore this
source of MSCs need deeper studies and require more attention. However, also if there are
79 registered clinical trial sites for evaluating MSC therapy throughout the world, it is still
a long way to go before using these cells as a routinely applied therapy in clinics.
PMID: 21072260 [PubMed - in process]
Am J Sports Med. 2010 Sep;38(9):1857-69. Epub 2010 May 27.
Repair of chronic osteochondral defects using predifferentiated mesenchymal stem cells
in an ovine model.
Zscharnack M, Hepp P, Richter R, Aigner T, Schulz R, Somerson J, Josten C, Bader A,
BACKGROUND: The use of mesenchymal stem cells (MSCs) to treat osteochondral
defects caused by sports injuries or disease is of particular interest. However, there is a
lack of studies in large-animal models examining the benefits of chondrogenic
predifferentiation in vitro for repair of chronic osteochondral defects.
HYPOTHESIS: Chondrogenic in vitro predifferentiation of autologous MSCs embedded in a
collagen I hydrogel currently in clinical trial use for matrix-associated autologous
chondrocyte transplantation facilitates the regeneration of a chronic osteochondral defect
in an ovine stifle joint.
STUDY DESIGN: Controlled laboratory study.
METHODS: The optimal predifferentiation period of ovine MSCs within the type I collagen
hydrogel in vitro was defined by assessment of several cellular and molecular biological
parameters. For the animal study, osteochondral lesions (diameter 7 mm) were created at
the medial femoral condyles of the hind legs in 10 merino sheep. To achieve a chronic
defect model, implantation of the ovine MSCs/hydrogel constructs was not performed until
6 weeks after defect creation. The 40 defects were divided into 4 treatment groups: (1)
chondrogenically predifferentiated ovine MSC/hydrogel constructs (preMSC-gels), (2)
undifferentiated ovine MSC/hydrogel constructs (unMSC-gels), (3) cell-free collagen
hydrogels (CF-gels), and (4) untreated controls (UCs). Evaluation followed after 6 months.
RESULTS: With regard to proteoglycan content, cell count, gel contraction, apoptosis,
compressive properties, and progress of chondrogenic differentiation, a differentiation
period of 14 days in vitro was considered optimal. After 6 months in vivo, the defects
treated with preMSC-gels showed significantly better histologic scores with morphologic
characteristics of hyaline cartilage such as columnarization and presence of collagen type
CONCLUSION: Matrix-associated autologous chondrocyte transplantation with
predifferentiated MSCs may be a promising approach for repair of focal, chronic
CLINICAL RELEVANCE: The results suggest an encouraging method for future treatment
of focal osteochondral defects to prevent progression to osteoarthritis.
PMID: 20508078 [PubMed - in process]
Orthopedics. 2010 Sep 7;33(9):661. doi: 10.3928/01477447-20100722-31.
Allograft alternatives: bone substitutes and beyond.
Excessive wear debris, deep infection, periprosthetic fracture, and other causes can lead
to bone loss associated with total joint replacements. When performing revisions,
surgeons are often preoccupied by the failed implant and the method of replacement, and
neglect an opportunity to replenish lost bone. Thus, when formulating a plan for revision
total joint replacement, the surgeon should consider not only the hardware that should be
used, but also ways in which lost bone could be restored. Autograft bone provides the
best source for osteoprogenitor cells, growth factors, and a scaffold. However, autograft is
limited in supply, and is generally associated with another incision, dissection, and
accompanying morbidity. Osteoconductive bone void fillers such as morselized
cancellous allograft bone, polymeric scaffolds, and biodegradable ceramics each have
their merits and deficiencies; however, all of these materials function as a scaffold only,
without the ability to induce bone formation. Osteoinductive growth factors are essential
to bone growth and remodeling; however, exogenous growth factors are expensive, are
given in large nonphysiological doses, may yield unpredictable clinical results, and may
have significant adverse effects. Demineralized bone matrix contains a scaffold and
variable amounts of several growth factors. Recently, the use of mesenchymal stem cells
and osteoprogenitors, together with a suitable scaffold carrier has gained increasing
popularity. With the addition of appropriate growth factors, this combination can provide
all the necessary components for osteogenesis. Future basic and clinical research will
define the indications and outcomes for new combination products for reconstruction of
lost bone associated with revision total joint replacement.
Copyright 2010, SLACK Incorporated.
PMID: 20839690 [PubMed - in process]
J Biomed Mater Res A. 2010 Aug 19. [Epub ahead of print]
Cartilage regeneration by bone marrow cells-seeded scaffolds.
Wegener B, Schrimpf FM, Bergschmidt P, Pietschmann MF, Utzschneider S, Milz S,
Jansson V, Müller PE.
Different approaches exist for the treatment of small articular cartilage defects. Several
studies show comparable results for autologous chondrocyte implantation (ACI) and
microfracture. Unfortunately, the fibrocartilage resulting from microfracture has neither
the structure nor the mechanical properties of hyaline cartilage, even though the adult