The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform

Michael G Dunn - One of the best experts on this subject based on the ideXlab platform.

Michael D Weir - One of the best experts on this subject based on the ideXlab platform.

  • effect of cell seeding density on proliferation and osteodifferentiation of umbilical cord stem cells on calcium phosphate cement Fiber Scaffold
    Tissue Engineering Part A, 2011
    Co-Authors: Hongzhi Zhou, Michael D Weir
    Abstract:

    Calcium phosphate cement (CPC) can fill complex-shaped bone defects and set in situ to form a Scaffold with intimate adaptation to neighboring bone. The objectives of this study were to determine (1) the effects of Fiber length and alginate microbead volume fraction on CPC mechanical properties, and (2) the effect of cell seeding density of human umbilical cord mesenchymal stem cells (hUCMSCs) on their proliferation and osteodifferentiation on CPC. Adding microbeads to CPC degraded the strength. However, increasing the Fiber length improved the mechanical properties. Strength and elastic modulus of CPC-microbead-Fiber Scaffold matched those reported for cancellous bone. When the cell seeding density was increased from 50k to 300k, the cell viability, osteodifferentiation, and bone mineral synthesis also increased. When the seeding density was further increased to 500k, the osteodifferentiation and mineralization decreased. Hence, the 300k seeding density was optimal for CPC-microbead-Fiber under the specified conditions. At day 8, alkaline phosphatase (ALP) gene expression of hUCMSCs with seeding density of 300k was threefold the ALP at 150k, and 200-fold the ALP at 50k. At day 14, osteocalcin and runt-related transcription factor 2 with cell seeding density of 300k was fourfold those at 50k. At day 14, mineralization by hUCMSCs at seeding density of 300k was 5-fold the mineralization at 150k, and 25-fold that at 50k. In conclusion, the effect of stem cell seeding density on CPC was determined for the first time. At low cell densities, cell viability and mineralization increased with seeding density. However, a higher seeding density was not necessarily better, and an optimal seeding density on CPC resulted in the best osteodifferentiation and mineralization. The stem cell-seeded CPC-Fiber Scaffold with excellent osteodifferentiation and mineralization is promising for orthopedic and craniofacial applications.

  • human umbilical cord stem cell encapsulation in calcium phosphate Scaffolds for bone engineering
    Biomaterials, 2010
    Co-Authors: Liang Zhao, Michael D Weir
    Abstract:

    Human bone marrow mesenchymal stem cells (hBMSCs) require an invasive procedure to harvest, and have lower self-renewal potential with aging. Umbilical cord mesenchymal stem cells (hUCMSCs) are a relatively new stem cell source; this study reveals a self-setting and load-bearing calcium phosphate construct that encapsulates these stem cells. The flexural strength (mean+/-sd; n=5) of the hUCMSC-encapsulating calcium phosphate cement (CPC) increased from (3.5+/-1.1) MPa without polyglactin Fibers, to (11.7+/-2.1) MPa with 20% of polyglactin Fibers (p<0.05). hUCMSCs attached to the bone mineral-mimicking Scaffold in the osteogenic media and differentiated down the osteogenic lineage, yielding elevated alkaline phosphatase (ALP) and osteocalcin (OC) gene expressions. ALP and OC on the CPC-Fiber Scaffold was 2-fold those on CPC control without Fibers. hUCMSCs encapsulated inside the Scaffolds retained excellent viability and cell density. The encapsulated hUCMSCs inside four different constructs successfully differentiated down the osteogenic lineage and synthesized bone minerals, as confirmed by mineral staining, SEM, and XRD. The percentage of mineral area synthesized by the encapsulated hUCMSCs increased from about 3% at day-7, to 12% at day-21 (p<0.05). In conclusion, this study demonstrated that hUCMSCs encapsulated in the bioengineered Scaffolds osteo-differentiated and synthesized bone minerals. The self-setting CPC-chitosan-Fiber Scaffold supported the viability and osteogenic differentiation of the encapsulated hUCMSCs, and had mechanical strength matching that of cancellous bone.

Xu Wang - One of the best experts on this subject based on the ideXlab platform.

  • polycaprolactone electrospun Fiber Scaffold loaded with ipscs nscs and ascs as a novel tissue engineering Scaffold for the treatment of spinal cord injury
    International Journal of Nanomedicine, 2019
    Co-Authors: Xianhu Zhou, Guidong Shi, Baoyou Fan, Xin Cheng, Xiaolei Zhang, Xu Wang
    Abstract:

    Background Spinal cord injury (SCI) is a traumatic disease of the central nervous system, accompanied with high incidence and high disability rate. Tissue engineering Scaffold can be used as therapeutic systems to provide effective repair for SCI. Purpose In this study, a novel tissue engineering Scaffold has been synthesized in order to explore the effect of nerve repair on SCI. Patients and methods Polycaprolactone (PCL) Scaffolds loaded with actived Schwann cells (ASCs) and induced pluripotent stem cells -derived neural stem cells (iPSC-NSCs), a combined cell transplantation strategy, were prepared and characterized. The cell-loaded PCL Scaffolds were further utilized for the treatment of SCI in vivo. Histological observation, behavioral evaluation, Western-blot and qRT-PCR were used to investigate the nerve repair of Wistar rats after Scaffold transplantation. Results The iPSCs displayed similar characteristics to embryonic stem cells and were efficiently differentiated into neural stem cells in vitro. The obtained PCL Scaffolds were0.5 mm in thickness with biocompatibility and biodegradability. SEM results indicated that the ASCs and (or) iPS-NSCs grew well on PCL Scaffolds. Moreover, transplantation reduced the volume of lesion cavity and improved locomotor recovery of rats. In addition, the degree of spinal cord recovery and remodeling maybe closely related to nerve growth factor and glial cell-derived neurotrophic factor. In summary, our results demonstrated that tissue engineering Scaffold treatment could increase tissue remodeling and could promote motor function recovery in a transection SCI model. Conclusion This study provides preliminary evidence for using tissue engineering Scaffold as a clinically viable treatment for SCI in the future.

Kaoru Yamagata - One of the best experts on this subject based on the ideXlab platform.

  • spontaneous differentiation of human mesenchymal stem cells on poly lactic co glycolic acid nano Fiber Scaffold
    PLOS ONE, 2016
    Co-Authors: Koshiro Sonomoto, Xiangmei Zhang, Kunihiro Yamaoka, Hiroaki Kaneko, Masahiro Kondo, Kaoru Yamagata, Kei Sakata, Yukichi Zenke, Ken Sabanai, Shingo Nakayamada
    Abstract:

    Introduction Mesenchymal stem cells (MSCs) have immunosuppressive activity and can differentiate into bone and cartilage; and thus seem ideal for treatment of rheumatoid arthritis (RA). Here, we investigated the osteogenesis and chondrogenesis potentials of MSCs seeded onto nano-Fiber Scaffolds (NFs) in vitro and possible use for the repair of RA-affected joints. Methods MSCs derived from healthy donors and patients with RA or osteoarthritis (OA) were seeded on poly-lactic-glycolic acid (PLGA) electrospun NFs and cultured in vitro. Results Healthy donor-derived MSCs seeded onto NFs stained positive with von Kossa at Day 14 post-stimulation for osteoblast differentiation. Similarly, MSCs stained positive with Safranin O at Day 14 post-stimulation for chondrocyte differentiation. Surprisingly, even cultured without any stimulation, MSCs expressed RUNX2 and SOX9 (master regulators of bone and cartilage differentiation) at Day 7. Moreover, MSCs stained positive for osteocalcin, a bone marker, and simultaneously also with Safranin O at Day 14. On Day 28, the cell morphology changed from a spindle-like to an osteocyte-like appearance with processes, along with the expression of dentin matrix protein-1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE), suggesting possible differentiation of MSCs into osteocytes. Calcification was observed on Day 56. Expression of osteoblast and chondrocyte differentiation markers was also noted in MSCs derived from RA or OA patients seeded on NFs. Lactic acid present in NFs potentially induced MSC differentiation into osteoblasts. Conclusions Our PLGA Scaffold NFs induced MSC differentiation into bone and cartilage. NFs induction process resembled the procedure of endochondral ossification. This finding indicates that the combination of MSCs and NFs is a promising therapeutic technique for the repair of RA or OA joints affected by bone and cartilage destruction.

  • local delivery of mesenchymal stem cells with poly lactic co glycolic acid nano Fiber Scaffold suppress arthritis in rats
    PLOS ONE, 2014
    Co-Authors: Xiangmei Zhang, Kunihiro Yamaoka, Koshiro Sonomoto, Hiroaki Kaneko, Makoto Satake, Yuka Yamamoto, Masahiro Kondo, Jidong Zhao, Ippei Miyagawa, Kaoru Yamagata
    Abstract:

    Mesenchymal stem cells (MSC) have been used recently for the treatment of autoimmune diseases in murine animal models due to the immunoregulatory capacity. Current utilization of MSC requires cells in certain quantity with multiple courses of administration, leading to limitation in clinical usage. Here we efficiently treated collagen-induced arthritis rats with a single local implantation with reduced number of MSC (2∼20% of previous studies) with nano-Fiber poly-lactic-co-glycolic acid (nano-Fiber) Scaffold. MSC seeded on nano-Fiber Scaffold suppressed arthritis and bone destruction due to inhibition of systemic inflammatory reaction and immune response by suppressing T cell proliferation and reducing anti- type II collagen antibody production. In vivo tracing of MSC demonstrated that these cells remained within the Scaffold without migrating to other organs. Meanwhile, in vitro culture of MSC with nano-Fiber Scaffold significantly increased TGF-β1 production. These results indicate an efficient utilization of MSC with the Scaffold for destructive joints in rheumatoid arthritis by a single and local inoculation. Thus, our data may serve as a new strategy for MSC-based therapy in inflammatory diseases and an alternative delivery method for bone destruction treatment.

Kejing Li - One of the best experts on this subject based on the ideXlab platform.

  • coaxial electrospun aligned tussah silk fibroin nanostructured Fiber Scaffolds embedded with hydroxyapatite tussah silk fibroin nanoparticles for bone tissue engineering
    Materials Science and Engineering: C, 2016
    Co-Authors: Weili Shao, Jianxin He, Feng Sang, Bin Ding, Li Chen, Kejing Li
    Abstract:

    The bone is a composite of inorganic and organic materials and possesses a complex hierarchical architecture consisting of mineralized fibrils formed by collagen molecules and coated with oriented hydroxyapatite. To regenerate bone tissue, it is necessary to provide a Scaffold that mimics the architecture of the extracellular matrix in native bone. Here, we describe one such Scaffold, a nanostructured composite with a core made of a composite of hydroxyapatite and tussah silk fibroin. The core is encased in a shell of tussah silk fibroin. The composite Fibers were fabricated by coaxial electrospinning using green water solvent and were characterized using different techniques. In comparison to nanoFibers of pure tussah silk, composite notably improved mechanical properties, with 90-fold and 2-fold higher initial modulus and breaking stress, respectively, obtained. Osteoblast-like MG-63 cells were cultivated on the composite to assess its suitability as a Scaffold for bone tissue engineering. We found that the Fiber Scaffold supported cell adhesion and proliferation and functionally promoted alkaline phosphatase and mineral deposition relevant for biomineralization. In addition, the composite were more biocompatible than pure tussah silk fibroin or cover slip. Thus, the nanostructured composite has excellent biomimetic and mechanical properties and is a potential biocompatible Scaffold for bone tissue engineering.