Papers by Keyword: Tissue Engineering

Abstract: Tissue engineering process has developed renewable materials used in a variety of applications. This research selected gelatin blended with CMC and fabricated by using salt-leaching technique. This technique does not require solvent, pressure or unnecessary expensive devices. The ratios of gelatin/CMC were 100/0(G1), 90/10(G2), 80/20(G3), 70/30(G4) and 60/40(G5), respectively. Crosslinking technique by using high temperature or dehydrothermal treatment (DHT) for improvement the properties of gelatin sponges brought to use in this research. The scaffolds were characterized the physical properties by observing the morphology using Scanning Electron Microscope (SEM) and measuring pore size of the scaffold from SEM images. The SEM images results revealed that the scaffolds occurred inter-connected porous structures which were found in 80/20 (G3), 70/30 (G4), and 60/40 (G5). The pore size of all scaffolds was in range of 113.46-212.82 μm. The compressive results revealed that the G3 scaffold occurred the highest compressive modulus which was 184 kPa whereas the mixture of 60/40(G5) ratio had lowest compressive modulus which was 23 kPa and the mixture 90/10(G2), 100/0(G1) and 70/30(G4) ratio were 75, 70 and 46 kPa, respectively.

Abstract: We review here the current research status on bioreactors for tissue engineering with cell electrical stimulation. Depending on the cell types, electrical stimulation has distinct objectives, in particular being employed both to mimic and enhance the endogenous electricity measured in the natural regeneration of living organisms as well as to mimic strain working conditions for contractible tissues (for instance muscle and cardiac tissues). Understanding the distinct parameters involved in electrical stimulation is crucial to optimize its application. The results presented in the literature and reviewed here reveal that the application of electrical stimulation can be essential for tissue engineering applications.

Abstract: Cartilage related diseases are on the top list concerns of the World Health Organization, being the prevention of articular cartilage degeneration a major health matter for which there are few effective solutions. Using an extrusion-based approach and a polyester elastomer it was aimed to produce 3D structures with controlled architecture and with closer mimicry to cartilage native tissue. The obtained constructs demonstrated high reliability, being the addition of poly (glycerol sebacate) a procedure to enhance the properties of the constructs.

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: To produce multi-material scaffolds for Tissue Engineering accurate techniques are needed in order to obtain three-dimensional constructs with clinically appropriate size and structural integrity. This paper presents a novel biomanufacturing system that can fabricate 3D scaffolds with precise shape and porosity which is achieved through the control of all fabrication modules by an integrated computational platform. The incorporation of a clean flow unit and a camera allows to obtain scaffolds in a clean environment and provides a monitoring tool to analyse constructs during the production, respectively. In this research work is demonstrated that the new system enables the fabrication of multi-material 3D structures using poly (e-caprolactone) and sodium alginate for potential use in Tissue Engineering applications.

Abstract: A way to produce 3D scaffold is via laser stereolithography. We propose a method of direct laser writing for micro-stereolithography in which we use as light source a low power blue diode laser with a wavelength of 448nm. The material chosen for scaffold fabrication is a polyethylene glycol diacrylate (PEGDA) solution at concentration of 75% in ethanol. We chose a short PEGDA molecule with a molecular weight of 575 g/mol, in order to obtain a better control over the polymerization. We used Irgacure 819 as photoinitiator to initiate the photopolymerization. The absorption of the Irgacure 819 almost drops to zero at the excitation wavelength, so the efficiency of the photopolymerization is strongly reduced. Since the intensity of the light reduces by a factor 5 within a penetration depth, equal to the depth of focus of the optical system, we achieve a fine control of the vertical and lateral photopolymerization of the solution. The threshold for effective polymerization is not reached outside that region.

Abstract: Tooth loss due to dental diseases, caries, and other related pathological conditions has plagued people and is the most prevalent cause of human organ failure. Billions of people have suffered from losing teeth and dental diseases so that generating natural dental tissues are more appreciated than artificial tooth implantation. The aspiration among the dentists to restore this loss biologically is the genesis of the tooth regeneration. Current trends initiate tissue engineering with a concept of functional restoration of tissue and organ defects by the triad of biomaterial scaffolds, growth factors, and stem cells (Rosa et al. 2012). This paper, therefore, focuses on the significance of nanostructured hybrid materials in the tooth regeneration through tissue engineering. For this purpose, literature was examined and studies on nanomorphological features of stem cells, dental tissues found within the oral area, the signaling molecules utilized in the tissue engineering, and the hybrid scaffolds that guide reconstructions of periodontal tissues were selected for the review. The nanodentistry has been potential, undoubtedly, to achieve almost perfect dental health in the nearest future. However, the success will largely be determined by human requirements and resource supply (technology, economy, and time). Finally, the future and actual potentials of nanotechnologies pertaining tissue engineering will be applied in dentistry (Mitziadis, Woloszyk, & Jimenez-Rojo, 2012). Keywords: Stem cells; scaffolds; nanomaterials; hybrid materials, tissue engineering; dentistry; signaling molecules.

Abstract: We previously reported that P19.CL6 cells can be cultured in porous hydroxyapatite ceramics prepared by firing green compacts consisting of apatite fibers and spherical carbon beads (150 μm in diameter). Cells cultured for 20 days in an apatite-fiber scaffold (AFS) proliferated and differentiated into cells expressing troponin T, a cardiomyocyte-specific gene, but the expression level was insufficient to support the functional maturation of cells required for biomedical device applications. In this study, we aimed to optimize the internal AFS environment for cardiomyocytes by mixing two sizes (150-and 20-μm) of carbon beads. P19.CL6 cells were cultured in AFS materials comprising different carbon ratios in the presence of alpha-MEM with (AFS+) or without (AFS-) dimethyl sulfoxide (DMSO), and cell growth and gene expression were assessed. We found that AFS(50, 1:1 ratio) is the most suitable scaffold for the proliferation and differentiation of P19.CL6 cells and the addition of DMSO to the culture medium is necessary for differentiation into cardiomyocytes. We also assessed the culture of P19.CL6 cells in AFS in a radial-flow bioreactor for several days.

Abstract: Three-dimensional (3D) printing has been playing an important role in diverse areas in medicine. In order to promote the development of tissue engineering, this study attempts to fabricate tissue engineering scaffolds using the inkjet printing technology. Sodium alginate, exhibiting similar properties to the native human extracellular matrix (ECM), was used as bioink. The jetted fluid of sodium alginate would be gelatinized when printed into the calcium chloride solution. The characteristics of the 3D-printed sodium alginate scaffold were systematically measured and analyzed. The results show that, the pore size, porosity and degradation property of these scaffolds could be well controlled. This study indicates the capability of 3D bioprinting technology for preparing tissue engineering scaffolds.

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.