Papers by Keyword: Regenerative Medicine

Abstract: The aim of the present review was to highlight some of the available processes for cartilage repair and regeneration. Considering the high impact that cartilage degeneration has in the quality of life, in an aging society, efforts to promote better treatments are crucial. The current available processes have advantages and drawbacks, that should be further investigated, aiming to obtain tailored and successful repair. Finally, some suggestions for tissue engineering strategies are presented, so that the scientific community can debate pros and cons to be investigated.

Abstract: Chronic kidney disease is a problem that has grown in recent decades worldwide. The National Kidney Foundation (NKF) estimates that the number of patients will double in the next 10 years. Dialysis and kidney transplantation are the treatments used for chronic kidney disease. There is hope in slowing down chronic kidney disease or even stopping its progression. Bioengineering and cell therapy are the main fields in kidney regeneration research using three-dimensional matrices in which cells are cultured, an ideal solution for scarcity organs for kidney transplantation. The difficulty in re-creating a functional kidney due to the complexity of its three-dimensional structure and its composition of different cell types and that can be incorporated in vivo with low immunogenicity is a very difficult task. Therefore, the aim of the present study was to meet the enormous demand for new treatments, developing strategies of tissue engineering on the basis of the decellularization of the porcine kidney performed through a new cell removal protocol. We determined the effective removal of cells by histologic and immunohistochemical analyses, showing the preservation of type IV collagen and fibronectin. Therefore, this method is a quick way to obtain decellularized porcine kidneys for future recellularization studies.

Abstract: Silica-calcium-phosphate composite (SCPC) is a drug delivery platform that has successfully demonstrated the ability to bind and release several therapeutics including antibiotics, peptides, anticancer drugs, and growth factors. It has successfully demonstrated a unique capacity for bone regeneration. The present studies address the effect of the phosphate and silicate functional groups on drug binding and controlled release kinetics of Cisplatin (Cis). Moreover, the roles of ceramic composition and resorbability on rhBMP2 release kinetics and bone regeneration in a critical size calvarial defect in rabbit is presented.

Abstract: Chimeric proteins have been used for years for various purposes ranging from biomaterials to candidate drug molecules, and from bench to bulk. Regenerative medicine needs various kinds of proteins for providing essential factors for maintaining starting cells, like induced pluripotent stem cells (iPSC), and renewal, proliferation, targeted differentiation of these cells, and as extracellular matrix for the experimental cells. However, there are several challenges associated with making functional chimeric proteins for effective application as biomaterial in this field. Fc-chimeric protein technology could be an effective solution to overcome many of them. These tailored proteins are recently becoming superior choice of biomaterials in stem cell technology and regenerative medicine due to their specific advantageous biophysical and biochemical properties over other chimeric forms of same proteins. Recent advances in recombinant protein-related science and technology also expedited the popularity of this kind of engineered protein. Over the last decade our lab has been pioneering this field, and we and others have been successfully applied Fc-chimeric proteins to overcome many critical issues in stem cell technologies targeting regenerative medicine and tissue engineering. Fc-chimeric protein-based biomaterials, specifically, E-cad-Fc have been preferentially applied for coating of cell culture plates for establishing xenogeneic-agent free monolayer stem cell culture and their maintenance, enhanced directed differentiation of stem cells to specific lineages, and non-enzymatic on-site one-step purification of target cells. Here the technology, recent discoveries, and future direction related with the E-cad-Fc-chimeric protein in connection with regenerative medicine are described.

Abstract: International standard for test method on cell migration into a scaffold is one of the important things to evaluate the scaffold. The "cell migration" ability can divide into two parts. One is infiltration of cell suspension before in vitro cell culture on the scaffold. Another is migration of adherent cells from the edge of scaffold. The latter one could be closely related to cell/tissue migration into the scaffold when it is implanted into bone. Thus, in the present study, the cell migration ability was evaluated toward standardization of in vitro evaluation method for in vivo cell/tissue migration ability using several bioactive ceramics and composites including commercially available materials. The specimen 5 mm in diameter was placed on confluent MG63 cell layer. After 3 days incubation, the specimen was harvested, fixed and divided into two parts. Inside and outside of the scaffold were stained by Giemsa and observed by optical microscopy. In addition, the same specimen was critical point dried and observed with scanning electron microscope (SEM). From microscopic observation, MG63 cells migrated to pore walls of the specimen as well as a sidewall. Maximum migration distances were different among specimens and seemed to depend on pore structure and size as well as porosity. Similar behaviors were observed with SEM.Even relations between this test method and in vivo cell/tissue migration have not been evaluated, this test method is potentially a good method for testing cell migration ability of porous bioactive ceramics as well as other porous scaffold materials.

Abstract: Historically the function of biomaterials has been to replace diseased, damaged and aged tissues. First generation biomaterials, including bio ceramics, were selected to be as inert as possible in order to minimize the thickness of interfacial scar tissue. Bioactive glasses provided an alternative from the 1970’s onward; second generation bioactive bonding of implants with tissues and no interfacial scar tissue. This chapter reviews the discovery that controlled release of biologically active Ca and Si ions from bioactive glasses leads to the up-regulation and activation of seven families of genes in osteoprogenitor cells that give rise to rapid bone regeneration. This finding offers the possibility of creating a new generation of gene activating bioceramics designed specially for tissue engineering and in situ regeneration of tissues.

Abstract: Biocompatible and water-soluble fibers (sodium carboxymethyl cellulose (CMC)) were fabricated via a wet-spinning method. The CMC fibers/ polymethyl methacrylate (PMMA) mixtures and CMC fibers/Poly (L-lactide-co-glycolide-co- -caprolactone) (PLGC) mixtures were prepared by a heat-kneading method. For CMC fibers/PMMA, after removal of the CMC fibers from the mixtures, the interconnected porous scaffolds with porosity from 27.79 % to 60.98 % (volume percent) were obtained. For CMC fibers/PLGC, the interconnected porous scaffolds with porosity 38.55 % and 76.83 % (volume percent) were prepared. The solid CMC fibers/PLGC mixtures had the higher ultimate tensile strength and Young, s modulus than those of porous PLGC scaffolds.

Abstract: The objective of this study was to evaluate cell adhesion and proliferation on the hydroxyapatite (HAp)-coated silk fibroin (SF) fabric. Nano-scaled sintered HAp particles were covalently coated on SF chemically modified by graft polymerization. After the fabrication of the HAp/SF composite, mesenchymal cells (MCs) derived from EGFP-expressing transgenic rat bone marrow were seeded on the composite and cultured for 10 days. Fluorescence and scanning electron microscopy (SEM) revealed that the cells adhered and actively proliferated on the composites comparable to those on tissue culture polystyrene (TCPS) dishes. The results suggest that the composites are suitable for mesenchymal cell culture scaffolds and useful materials for regenerative medicine.

Abstract: The aim of this experiment is to investigate whether MSCs from Banna Minipig Inbred Line (BMI) could be immortalized by introducing SV40 large T antigen gene. MSCs were isolated from BMI and transfected with pSV3neo plasmid. Normal BMI-MSCs would apoptosis and senescence during proliferation while its population doubling (PD) number exceeded 20. However, SV40-transfected cells were immortal. As same as that of normal BMI-MSCs, transfected MSCs were positive for stem cell markers and negative for differentiated osteoblast specific marker. After cultured in osteogenesis supplement media, cbfa1 and calcium deposit on stimulated cells were enhanced obviously. There were no data to prove the tumorigenicity potential of the immortalized cells. Furthermore, histological analysis demonstrated that bone formation was initiated in the pores of HA/TCP implants loaded immortalized BMI-MSCs 7 weeks postimplantation. BMI-MSCs were immortalized by introducing SV40 large T antigen into the cells and still kept the stem cell characters and might be used as seeding cells for tissue engineering as well as stable test cells for biocompatibility of bone biomaterials.