Recently, regenerative medicine utilizing tissue manufacturing has been a creative topic of study, offering promise for resolving the gap between insufficient organ supply and transplantation needs. Moreover, 3D generation of functional organs is seen as the main hope to resolve these issues that will be a major advancement in the field over the next generation. Organ printing is the 3D construction of functional cellular tissue that can replace organs made by additive biofabrication with computational technology. Its advantages offer rapid prototyping (RP) methods for fabricating cells and adjunctive biomaterials layer by layer for manufacturing 3D tissue structures. There is growing interest in applying stem cell research to bio-printing. Recently several bio-printing methods have been developed that accumulate organized 3D structures of living cells by inkjet, extrusion, and laser based printing systems. By printing spatially organized gradients of biomolecules as an extracellular matrix, direct stem cell seeding can then be engineered to differentiate into different lineages forming multiple subpopulations that closely approximate the desired organ. Pliable implementation patches can Stem cells for tissue regeneration can be arranged or deposited onto pliable implementation patches with the purpose of generating functional tissue structures. In this review, current research and advancement of RP-based bio-printing methods to construct synthetic living organs will be discussed. Furthermore, recent accomplishments in bioprinting methods for stem cell study and upcoming endeavors relevant to tissue bioengineering, regenerative medicine and wound healing will be examined.
Biocompatible Materials ; Bioengineering ; Bioprinting ; Extracellular Matrix ; Hope ; Imaging, Three-Dimensional ; Organ Transplantation* ; Regeneration ; Regenerative Medicine ; Stem Cell Research ; Stem Cells ; Tissue Engineering ; Transplants* ; Wound Healing

Neomorphogenesis of cartilage using chondrocyte-polymer constructs is a potential source for development of cartilage reconstruction. Current tissue engineering techniques of neocartilage rely on in vivo implantation of polymer-chondrocyte constructs. The purpose of this study was to find a way to bioengineer cartilage in vitro by entrapping chondrocytes in a molded autologous fibrin glue. Chondrocytes isolated from the cartilage of rabbit joints were combined with fibrinogen extracted by a single cryoprecipitation of autologous plasma, and they were then polymerized with thrombin to create a fibrin glue with a final cell density of 2.5x10(6) cells/ml. The collagen for a control study was used as a polymer. The polymer-chondrocyte constructs were cultured for 4 weeks and the fibrin-chondrocyte constructs molded in the shape of a human ear were cultured for 6 weeks in vitro. Morphometric, histochemical, and histomorphometric analysis including glycosaminoglycan quantitation confirmed the following results: 1) Highly-concentrated autologous fibrinogen was easily extracted by a single cryoprecipition of autologous olasma. 2) The fibrin-chondrocyte constructs demonstrated the presence of actively proliferating chondrocytes with the production of cartilaginous matrix(collagen and glycosaminoglycan) at 1 week after culture, as well as gross and histologic evidence similar to those of normal cartilage at 3-4 weeks after culture. 3) The collagen-chondrocyte constructs demonstrated lower degrees of hardness and transparency, as well as a lower density of cells and glycosaminoglycan during the culture period. 4) Neocartilage generated from fibrin-chondrocyte constructs in the shape of a human ear nearly retained their original configuration and size without degeneration for 6 weeks of culture in vitro. This study demonstrated a novel method for bioengineering the molded cartilage in vitro using autologous fibrin glue as a matrix scaffold. The generated cartilage showed gross and histologic evidence similar to those of normal cartilage, retaining the original gross dimension. With further refinement, this may be a new application of tissue engineering for the reconstruction of cartilage.
Bioengineering ; Cartilage* ; Cell Count ; Chondrocytes* ; Collagen ; Ear ; Fibrin Tissue Adhesive* ; Fibrin* ; Fibrinogen ; Fungi ; Hardness ; Humans ; Joints ; Plasma ; Polymers ; Thrombin ; Tissue Engineering*

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, or other clinical issues. Currently, patients with diseased and injured organs are often treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and as the number of new cases of organ failure increases. Scientists in the field of regenerative medicine and tissue engineering are now applying the principles of cell transplantation, material science, and bioengineering to construct biological substitutes that can restore and maintain normal function in diseased and injured tissues. In addition, the stem cell field is a rapidly advancing part of regenerative medicine, and new discoveries in this field create new options for this type of therapy. For example, new types of stem cells, such as amniotic fluid and placental stem cells that can circumvent the ethical issues associated with embryonic stem cells, have been discovered. The process of therapeutic cloning and the creation of induced pluripotent cells provide still other potential sources of stem cells for cell-based tissue engineering applications. Although stem cells are still in the research phase, some therapies arising from tissue engineering endeavors that make use of autologous, adult cells have already entered the clinical setting, indicating that regenerative medicine holds much promise for the future.
Adult ; Amniotic Fluid ; Biocompatible Materials ; Bioengineering ; Cell Transplantation ; Clone Cells ; Cloning, Organism ; Embryonic Stem Cells ; Female ; Humans ; Regenerative Medicine ; Stem Cells ; Tissue Donors ; Tissue Engineering ; Transplants

In the last decade, spine surgery has advanced tremendously. Tissue engineering and three-dimensional (3D) printing/additive manufacturing have provided promising new research avenues in the fields of medicine and orthopedics in recent literature, and their emergent role in spine surgery is encouraging. We reviewed recent articles that highlighted the role of 3D printing in medicine, orthopedics, and spine surgery and summarized the utility of 3D printing. 3D printing has shown promising results in various aspects of spine surgery and can be a useful tool for spine surgeons. The growing research on tissue bioengineering and its application in conjunction with additive manufacturing has revealed great potential for tissue bioengineering in the treatment of spinal ailments.
Bioengineering ; Orthopedics ; Printing, Three-Dimensional ; Spine ; Surgeons ; Tissue Engineering

PURPOSE: These days, mesenchymal stem cells (MSCs) have received worldwide attention because of their potentiality in tissue engineering for implant dentistry. The purpose of this study was to evaluate various growth inducing factors in media for improvement of acquisition of bone marrow mesenchymal stem cells (BMMSCs) and colony forming unit-fibroblast (CFU-F). MATERIALS AND METHODS: The mouse BMMSCs were freshly obtained from female C3H mouse femur and tibia. The cells seeded at the density of 106/dish in media supplemented with different density of fetal bovine serum (FBS), 1alpha, 25-dihydroxyvitamin (VD3) and recombinant human epidermal growth factor (rhEGF). After 14 days, CFU-F assay was conducted to analyze the cell attachment and proliferation, and moreover for VD3, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was additionally conducted. RESULTS: The cell proliferation was increased with the increase of FBS concentration (P<.05). The cell proliferation was highest at the density of 20 ng/mL rhEGF compared with 0 ng/mL and 200 ng/mL rhEGF (P<.05). For VD3, although the colony number was increased with the increase of its concentration, the difference was not statistically significant (P>.05). CONCLUSION: FBS played the main role in cell attachment and growth, and the growth factor like rhEGF played the additional effect. However, VD3 did not have much efficacy compare with the other two factors. Improvement of the conditions could be adopted to acquire more functional MSCs to apply into bony defect around implants easily.
Animals ; Bioengineering* ; Bone Marrow ; Cell Proliferation ; Dentistry ; Epidermal Growth Factor ; Female ; Femur ; Humans ; Mesenchymal Stromal Cells* ; Mice ; Mice, Inbred C3H ; Tibia ; Tissue Engineering

In this review, we focused on a few obstacles that hinder three-dimensional (3D) bioprinting process in tissue engineering. One of the obstacles is the bioinks used to deliver cells. Hydrogels are the most widely used bioink materials; however, they aremechanically weak in nature and cannot meet the requirements for supporting structures, especially when the tissues, such as cartilage, require extracellular matrix to be mechanically strong. Secondly and more importantly, tissue regeneration is not only about building all the components in a way that mimics the structures of living tissues, but also about how to make the constructs function normally in the long term. One of the key issues is sufficient nutrient and oxygen supply to the engineered living constructs. The other is to coordinate the interplays between cells, bioactive agents and extracellular matrix in a natural way. This article reviews the approaches to improve the mechanical strength of hydrogels and their suitability for 3D bioprinting; moreover, the key issues of multiple cell lines coprinting with multiple growth factors, vascularization within engineered living constructs etc. were also reviewed.
Animals ; Bioprinting ; Cell Line ; Humans ; Hydrogels ; Nanoparticles ; Tissue Engineering

Current investigations on the bioengineering of female reproductive tissues have created new hopes for the women suffering from reproductive organ failure including congenital anomaly of the female reproductive tract or serious injuries. There are many surgically restore forms that constitute congenital anomaly, however, to date, there is no treatment except surgical treatment of transplantation for patients who are suffering from anomaly or dysfunction organs like vagina and uterus. Restoring and maintaining the normal function of ovary and uterus require the establishment of biological substitutes that can cover the roles of structural support for cells and passage of secreting molecules. As in the case of constructing other functional organs, reproductive organ manufacturing also needs biological matrices which can provide an appropriate condition for attachment, growth, proliferation and signaling of various kinds of grafted cells. Among the organs, uterus needs special features such as plasticity due to their amazing changes in volume when they are in the state of pregnancy. Although numerous natural and synthetic biomaterials are still at the experimental stage, some biomaterials have already been evaluated their efficacy for the reconstruction of female reproductive tissues. In this review, all the biomaterials cited in recent literature that have ever been used and that have a potential for the tissue engineering of female reproductive organs were reviewed, especially focused on bioengineered ovary and uterus.
Biocompatible Materials* ; Bioengineering ; Female* ; Hope ; Humans ; Ovary ; Plastics ; Pregnancy ; Tissue Engineering* ; Transplants ; Uterus ; Vagina

Liver transplantation is the only known treatment for patients with end-stage liver failure, but this therapy is limited by the shortage of donor organs. Hepatic tissue engineering combining biomaterial scaffolds and cells have been used as a promising strategy to create engineered liver graft for liver regeneration. Despite significant progress in this field, attempts to create clinically transplantable whole organs have not been as nearly successful. Recently, whole organ decellularization techniques have emerged as a new therapeutic strategy for organ replacement and provided feasibility for clinical translation. The perfusion decellularization method was applied to the whole organ for efficient removal of cellular components and generated organ scaffolds that can maintain the extracellular matrix (ECM) and vascular structure of the native organ. This review paper describes current progress in organ bioengineering for the development of transplantable liver grafts.
Bioengineering ; Extracellular Matrix ; Humans ; Liver ; Liver Failure ; Liver Regeneration ; Liver Transplantation ; Organ Transplantation* ; Perfusion ; Tissue Donors ; Tissue Engineering ; Transplants*

With more than 20 years of development, Pichia pastoris system has been extensively used both on a lab and industrial scale. This review outlines the progress made on P. pastoris from aspects of protein expression, molecular engineering tools and methods, and biochemical production. This review also provides perspectives on the current challenges and future directions of this important system.
Bioengineering ; Industrial Microbiology ; Pichia

Engineering three-dimensional (3D) implantable tissue constructs is a promising strategy for replacing damaged or diseased tissues and organs with functional replacements. However, the efficient vascularization of new 3D organs is a major scientific and technical challenge since large tissue constructs or organs require a constant blood supply to survive in vivo. Current approaches to solving this problem generally fall into the following three major categories: (a) cell-based, (b) angiogenic factor-based, and (c) scaffold-based. In this review, we summarize state-of-the-art technologies that are used to develop complex, stable, and functional vasculature for engineered 3D tissue constructs and organs; additionally, we have suggested directions for future research.
Bioengineering ; Tissue Scaffolds