Factor In Tissue Engineering Research Articles

3D scaffolds-specific cellular mechanoresponse as a pivotal regulating factor in tissue engineering

3D scaffolds-specific cellular mechanoresponse as a pivotal regulating factor in tissue engineering

Evaluation of extruded starch foam for glucose-supplying biomaterials

The survival rate of mesenchymal stem cells (MSC), a crucial factor in tissue engineering, is highly dependent on glucose supply. The purpose of this paper is to study the potential of starch foams as glucose suppliers. It is investigated through in vitro hydrolysis by amyloglucosidase in conditions that respect physiological constraints (37 °C and pH 7.4), including a duration of 21 days, and no stirring. Nine extruded starch foams with amylose contents ranging from 0 to 74 %, with various cell wall thicknesses (50 to 300 μm), and different crystallinities (0–30 %) were hydrolysed. These kinetics were fitted by a model which shows that the maximum rate of hydrolysis varies from 7 to 100 %, and which allows the rate of hydrolysis at 21 days to be calculated precisely. The results reveal the major role of amylose in glucose delivery kinetics, and the secondary roles of crystallinity and cell wall thickness of the foams. Additional hydrolysis of starch films revealed that thickness positively influences the amylose chain reorganisation during hydrolysis, which, in slows down and limits glucose delivery. A simple glucose delivery kinetics analysis procedure is proposed to select samples for testing as MSC glucose suppliers.

Effect of gelatinous spongy scaffold containing nano-hydroxyapatite on the induction of odontogenic activity of dental pulp stem cells

Tissue engineering methods may be applied for the repair or regeneration of damaged teeth by inducing cell proliferation and differentiation in endodontic regeneration. One of the main factors in tissue engineering is the scaffold used. An ideal scaffold should be able to facilitate predictable tissue development in endodontic regeneration. Thus, tissue engineering requires consideration for the composition and functionality of the scaffold suited for biological applications. The objective of this study was to assess the morphological, physico-chemical, and biological properties of a new gelatin (Gel)-nano-hydroxyapatite (nHA)-based scaffold to be applied in endodontic regeneration. The scaffold containing gelatin and nHA was prepared by a freeze-drying method. Conventional techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and dynamic light scattering (DLS) analysis were used to evaluate the physico-chemical properties of the fabricated Gel-nHA sponge scaffold. Biological examination for cell survival and differentiation of dental pulp stem cells (DPSCs) was evaluated by the MTT assay and ALP activity techniques, respectively. The produced Gel-nHA scaffold had spongy properties that all functional groups of gelatin and hydroxyapatite were present in the sponge. In biological studies, the viability of the cells grown on Gel-nHA scaffold had no different change from the control group on days 2nd, 4th, and 6th. Besides, after 14 days of cells cultured on Gel-nHA, alkaline phosphatase (ALP) activity showed a significant increment. In summary, the Gel-nHA scaffold revealed favorable effects on odontogenic activity, implying a potential future for application in endodontic regeneration.

A review on fabrication of 3D printed biomaterials using optical methodologies for tissue engineering applications.

Human body comprises of different internal and external biological components. Human organs tend to fail due to continuous or sudden stress which leads to deterioration, failure, and dislocation. The choice of selection and fabrication of materials for tissue engineering play a key role in terms of suitability, sensitivity, and functioning with other organs as a replacement for failed organs. The progressive improvement of the additive manufacturing (AM) approach in healthcare made it possible to print multi-material and customized complex/intricate geometries in a layer-by-layer fashion. The customized or patient-specific implant fabrication can be easily produced with a high success rate due to the development of AM technologies with tailorable properties. The structural behavior of 3D printed biomaterials is a crucial factor in tissue engineering as they affect the functionality of the implants. Various techniques have been developed in appraising the important features and the effects of the subsequent design of the biomaterial implants. The behavior of the AM built biomaterial implants can be understood visually by an imaging system with a high spatial and spectral resolution. This review intends to present an overview of various biomaterials used in implants, followed by a detailed description of optical 3D printing procedures and evaluation of the performance of 3D printed biomaterials using optical characterization.

Cold Argon Athmospheric Plasma for Biomedicine: Biological Effects, Applications and Possibilities.

Currently, plasma medicine is a synthetic direction that unites the efforts of specialists of various profiles. For the successful formation of plasma medicine, it is necessary to solve a large complex of problems, including creating equipment for generating cold plasma, revealing the biological effects of this effect, as well as identifying and justifying the most promising areas of its application. It is known that these biological effects include antibacterial and antiviral activity, the ability to stimulate hemocoagulation, pro-regenerative properties, etc. The possibility of using the factor in tissue engineering and implantology is also shown. Based on this, the purpose of this review was to form a unified understanding of the biological effects and biomedical applications of argon cold plasma. The review shows that cold plasma, like any other physical and chemical factors, has dose dependence, and the variable parameter in this case is the exposure of its application. One of the significant characteristics determining the specificity of the cold plasma effect is the carrier gas selection. This gas carrier is not just an ionized medium but modulates the response of biosystems to it. Finally, the perception of cold plasma by cellular structures can be carried out by activating a special molecular biosensor, the functioning of which significantly depends on the parameters of the medium (in the field of plasma generation and the cell itself). Further research in this area can open up new prospects for the effective use of cold plasma.

Comparison of Selective Laser Melted Commercially Pure Titanium Sheet‐Based Triply Periodic Minimal Surfaces and Trabecular‐Like Strut‐Based Scaffolds for Tissue Engineering

This systematic comparison between sheet‐based triply periodic minimal surfaces (TPMS) and strut‐based ordered and disordered lattice topologies offers insights into parametric designs for tissue engineering scaffolds intended as implants. The study explores the effect of topology on compressive properties and in vitro osteoblastogenesis. TPMS‐sheet gyroid and IWP, Voronoi tessellation with different sharpness, and cubic orthogonal lattices are studied. Disparities between the design intent and the as‐manufactured scaffolds, intrinsic to selective laser processing, are considered to ensure that actual porosity and surface area per unit volume, two important factors in tissue engineering, are consistent across the set. Surface analysis reports the presence of microporosity created by partly sintered titanium particles. The TPMS topologies display a stretching‐dominated deformation and the strut‐based disordered ones a bending‐dominated double‐shear failure. Although the trabecular‐like structures exhibit an enhanced compressive behavior when the designed topology is smoothed, they are more prone to printing imperfections with sharper finishes. The in vitro studies reveal that the trabecular sharp topology displays a faster proliferation rate, explained by concavity‐driven cellular growth, but its smooth counterpart promotes a larger differentiation extent, outperforming TPMS, as it is aided by larger pore throats lined with microporosity at the scale of osteoblastic geometric features.

DNA-DAPI Interaction-Based Method for Cell Proliferation Rate Evaluation in 3D Structures.

Effective cell number monitoring throughout the three-dimensional (3D) scaffold is a key factor in tissue engineering. There are many methods developed to evaluate cell number in 2D environments; however, they often encounter limitations in 3D. Therefore, there is a demand for reliable methods to measure cell proliferation in 3D surroundings. Here, we report a novel technique for the DNA content-based evaluation of cell proliferation using DNA-binding dye DAPI. We demonstrated the method’s compatibility with four different cell cultures: cancer lines MCF-7 and MH-22a, embryonic fibroblast cell line Swiss 3T3, and primary mesenchymal stem cell culture isolated from rat’s incisors. The DAPI based method was able to successfully evaluate cell proliferation in 2D, 2.5D, and 3D environments. Even though the proposed method does not discriminate between viable and dead cells, it might give a convenient snapshot of the cell number at a given time point. This should help to more reliably evaluate various processes proceeding in 2.5D and 3D cultures.

A Green Composite Based on Gelatin/Agarose/Zeolite as a Potential Scaffold for Tissue Engineering Applications

Designing a novel platform capable of providing a proper tissue regeneration environment is a key factor in tissue engineering. Herein, a green composite based on gelatin/agarose/zeolite with pomegranate peel extract was fabricated as an innovative platform for tissue engineering. Gelatin/agarose was loaded with pomegranate peel extract-loaded zeolite to evaluate its swelling behavior, porosity, release rate, and cell viability performance. The composite characteristics were evaluated using XRD and DSC. The hydrogel performance can be adjusted for the desired aim by zeolite content manipulation, such as controlled release. It was shown that the green nanocomposite exhibited proper cellular activity along with a controlled release rate. Moreover, the hydrogel composite’s swelling ratio was decreased by adding zeolite. This study suggested a fully natural composite as a potential biomaterial for tissue engineering, which opens new ways to design versatile hydrogels for the regeneration of damaged tissues. The hydrogel performance can be adjusted specifically by zeolite content manipulation for controlled release.

Incorporation of VEGF-and bFGF-loaded alginate oxide particles in acellular collagen-alginate composite hydrogel to promote angiogenesis

BackgroundThe use of growth factors in tissue engineering is often challenging due to their instability and short half-life. The delivery of growth factors with nanocarriers can eliminate these problems. In the present study, we introduced an alginate oxide particle in acellular collagen-alginate composite hydrogel platform for the immobilization and controlled release of VEGF and bFGF to promote angiogenesis. MethodsThe particles were prepared by the oxidation of sodium alginate. Then, they were embedded in collagen-alginate hydrogel. Cytocompatibility of the construct with the human umbilical vein endothelial cells was analyzed through a live/dead assay and scanning electron microscopy. In vitro evaluation of VEGF and bFGF Release Kinetics was done. Moreover, the function of the constructs was confirmed through the chick chorioallantoic membrane assay. ResultsThe engineered constructs maintained the human umbilical vein endothelial cells viability, which indicates the non-toxicity of the tested constructs. The presence of VEGF-loaded particles could improve the Total Branching Points in the chick chorioallantoic membrane assay. In this regard, Total Branching Points was significantly improved in the VEGF group compared to the control group (p = 0.010) and FGF group (p = 0.023). ConclusionThe results demonstrated the potential role of these particles in regenerative medicine to improve angiogenesis.

Applications of Small Molecules in Muscle Tissue Engineering

Introduction: Skeletal muscles account for about 40% of the total body weight. Every year, hundreds of people lose at least part of their muscle tissue due to illness, war, and accidents. This can lead to disruption of activities such as breathing, movement, and social life. To this end, various therapeutic strategies such as medication therapy, cell therapy and tissue transplantation have been used or studied in muscle regeneration. However, there is no effective and well-defined clinical approach for treatment of muscle injuries and the severity of muscle injuries increase with age in most cases. Therefore, investigation for finding new and effective clinical approach for muscle regeneration is one of the most important issues in basic and clinical researches. Tissue engineering is considered as one of the promising and newest approach for skeletal muscle tissue regeneration and provides an appropriate model for personalized medicine and basic researches that can be used in personalized medicine and basic research. Besides biomaterials and cells, inducing factors are another element of tissue engineering. These factors influence epigenetic mechanisms and signaling pathway, thereby inducing proliferation, differentiation, and migration of cells used in muscle tissue engineering, and accelerates muscle formation in vitro. Recently, small molecules have been used as alternatives to growth factors or along with other inducing factors in muscle tissue engineering. Since they do not induce an immune reaction, penetrate easily to the cells and have a specific molecular target, therefore they have attracted much attention as the cost-effective inducing factors in tissue engineering. Conclusion: Taken together, the effective small molecules in muscle tissue engineering can be used with different biomaterial conditions (e.g. hydrogel, decellularized tissue, and synthetic scaffolds) in both in vivo and in vitro, resulting to production of cost effective and highly efficient engineered muscle tissues that help to achieve therapeutical goals of muscle tissue engineering. Herein, we describe tissue engineering and review the small molecules used in skeletal muscle tissue engineering.

SCAFOLDS IN PERIODONTAL SURGERY. Review

Relevance. Substitution of bone defects in destructive periodontitis is one of the most difficult tasks of maxillofacial surgery. Today, tissue engineering, which makes up the classical triad: biomaterials + cells + growth factors, is the most effective and technologically promising for restoring the parameters and structure of the alveolar bone. Objective. The goal is to summarize of literature data on the possibilities of using modified scaffold materials, bone morphogenetic proteins, growth factors in tissue engineering in the replacement of jaw bone defects. Materials and methods.Scientific literature search was carry out using scientometric bases such as Scopus, PubMed, Web of Science, RSCI during 18 years (2001-2018). The literature sources on the possibility of using osteoinductive and osteoconductive materials in dentistry is analyzed. Also the data on the possibility and prospects of using individual osteoregenerative drugs for periodontal diseases and for the elimination of jaw defects was analyzed. The characteristics of the composition, properties, manufacturing methods and mechanism of action of osteoplastic materials was analyzed. Results. Advantages of osteoreparative technologies using scaffolds are their sufficient hydrophilicity, the possibility of complete biocompatibility, biodegradation of the material without any toxic effects on the patient’s body, the possibility of penetration into the cell structure and different molecular sizes (including those stimulating angiogenesis), maintaining the required volume, the possibility of programming the composition and properties at the manufacturing stage and the like. Tissue-engineering constructs have shown their high mechanical and biological properties for osteogenic differentiation and cell replacement. In addition, it is possible to expand operational protocols depending on the specific anatomical and physiological conditions in each patient. Conclusion. The use of modified scaffold materials, bone morphogenetic proteins, growth factors in tissue engineering allows us to restore the structure and volume when replacing defects in the bone tissue of the jaw. Tissue engineering (matrices, growth factors, cells) is becoming an attractive clinical approach for bone regeneration.

Aging: A cell source limiting factor in tissue engineering.

Tissue engineering has yet to reach its ideal goal, i.e. creating profitable off-the-shelf tissues and organs, designing scaffolds and three-dimensional tissue architectures that can maintain the blood supply, proper biomaterial selection, and identifying the most efficient cell source for use in cell therapy and tissue engineering. These are still the major challenges in this field. Regarding the identification of the most appropriate cell source, aging as a factor that affects both somatic and stem cells and limits their function and applications is a preventable and, at least to some extents, a reversible phenomenon. Here, we reviewed different stem cell types, namely embryonic stem cells, adult stem cells, induced pluripotent stem cells, and genetically modified stem cells, as well as their sources, i.e. autologous, allogeneic, and xenogeneic sources. Afterward, we approached aging by discussing the functional decline of aged stem cells and different intrinsic and extrinsic factors that are involved in stem cell aging including replicative senescence and Hayflick limit, autophagy, epigenetic changes, miRNAs, mTOR and AMPK pathways, and the role of mitochondria in stem cell senescence. Finally, various interventions for rejuvenation and geroprotection of stem cells are discussed. These interventions can be applied in cell therapy and tissue engineering methods to conquer aging as a limiting factor, both in original cell source and in the in vitro proliferated cells.

Human Oral Stem Cells, Biomaterials and Extracellular Vesicles: A Promising Tool in Bone Tissue Repair.

Tissue engineering and/or regenerative medicine are fields of life science exploiting both engineering and biological fundamentals to originate new tissues and organs and to induce the regeneration of damaged or diseased tissues and organs. In particular, de novo bone tissue regeneration requires a mechanically competent osteo-conductive/inductive 3D biomaterial scaffold that guarantees the cell adhesion, proliferation, angiogenesis and differentiation into osteogenic lineage. Cellular components represent a key factor in tissue engineering and bone growth strategies take advantage from employment of mesenchymal stem cells (MSCs), an ideal cell source for tissue repair. Recently, the application of extracellular vesicles (EVs), isolated from stem cells, as cell-free therapy has emerged as a promising therapeutic strategy. This review aims at summarizing the recent and representative research on the bone tissue engineering field using a 3D scaffold enriched with human oral stem cells and their derivatives, EVs, as a promising therapeutic potential in the reconstructing of bone tissue defects.

Research progress in pulp tissue regeneration strategy in microenvironment

Pulpal and periapical diseases are the common diseases in human diseases. The traditional treatment method for these diseases is root canal treatment, which is to completely remove and control infection, repair or prevent periapical lesions by root canal mechanical preparation, chemical disinfection and filling. At present, although root canal treatments have a high success rate, there are still a series of problems. Dental pulp regeneration has attracted more and more attention from researchers in promoting the formation of pulp-like tissue in root canals. The ultimate goal of regenerative endodontics is to form a functional endodontic-dentin complex with inner blood vessels and nerves, outer layers of dentin cells arranged along the root canal wall, and new dentin formed by secreting matrix, so as to restore pulp vitality. Stem cells, scaffolds, biosignal molecules, and regenerative microenvironment are key tissue engineering factors that affect pulp regeneration. In this paper, the strategies and applications of pulp regeneration were reviewed around the above factors and clinical procedures. Key words: Pulp tissue regeneration; Pulp revascularization; Tissue engineering; Cell transplantation; Cells homing; Scaffolds; Microenviroment

Magnetic Cell-Scaffold Interface Constructed by Superparamagnetic IONP Enhanced Osteogenesis of Adipose-Derived Stem Cells.

One of the key factors in tissue engineering and regenerative medicine is to optimize the interaction between seed cells and scaffolds such that the cells can grow in naturally biomimetic conditions. Their similarity to macromolecules and many unique properties mean that functional nanoparticles have promising potential for the modification and improvement of traditional scaffolds to obtain excellent biocompatibility, tunable stiffness, physical sensing, and stimulus-response capabilities. In the present study, we report magnetic poly(lactic- co-glycolic acid)/polycaprolactone (PLGA/PCL) scaffolds that were fabricated using a combination of the electrospinning technique and layer-by-layer assembly of superparamagnetic iron oxide nanoparticles (IONPs). PLGA/PCL scaffolds assembled with gold nanoparticles were prepared using the same method for comparison. The results showed that the assembled film of nanoparticles on the surface greatly enhanced the hydrophilicity and increased the elastic modulus of the scaffold, which subsequently improved the osteogenesis of the stem cells. Furthermore, the magnetic property of the IONPs proved to be the key factor in enhancing osteogenic differentiation, which explained the superior osteogenic capacity of the magnetic scaffolds compared with that of the gold nanoparticle-assembled scaffold. These results demonstrated the importance of magnetic nanomaterials as a bioactive interface between cells and scaffolds and will promote the design of biomaterials to improve tissue engineering and regenerative medicine efficacy.

Effects of Tunable Keratin Hydrogel Erosion on Recombinant Human Bone Morphogenetic Protein 2 Release, Bioactivity, and Bone Induction.

Recombinant human bone morphogenetic protein 2 (rhBMP-2) delivery from collagen sponges for bone formation is an important clinical example of growth factors in tissue engineering. Side effects from rhBMP-2 burst release and rapid collagen resorption have led to investigation of alternative carriers. Here, keratin carriers with tunable erosion rates were formulated by varying disulfide crosslinking via ratios of oxidatively (keratose) to reductively (kerateine) extracted keratin. In vitro rhBMP-2 bioactivity increased with kerateine content, reaching levels greater than with collagen. Heterotopic bone formation in a mouse model depended on the keratin formulation, highlighting the importance of the growth factor carrier.

Degradation profile of synthetic coral scaffold in cell culture media

<p>The scaffold is one of the factors in tissue engineering that determine the success of bone regeneration. The important characteristic of the scaffold is able to degrade gradually. In vitro study using cells, the scaffold will be exposed to culture media. Therefore, degradation profile for scaffold needs to be examined. This study aims to investigate the degradation profile of synthetic coral scaffold in cell culture media using pH measurement. The method used the synthetic coral scaffolds were prepared from denaturalized collagen (gelatin) and calcium carbonate (calcite) with a concentration of 5:5 and 4:6 weight % in aqua dest. The scaffold<span lang="IN" style="">s</span> were fabricated in membrane thick film which was then physically crosslinked.  <span lang="IN" style="">The </span>10 % <span lang="IN" style="">of gelatin scaffold was used as a control.</span>  The scaffolds were incubated in cell culture media (non-phenol red Dulbecco’s Modified Eagle Medium) for 1 until 8 days, and pH changes of the medium were measured. As the result, Profile of degradation on day 1 to day 4 showed the 5:5 scaffold had the smallest degradation. The results indicated the significant different between scaffold concentration in day 1 (p=0.005), 5th(p=0.03), and 6th day (p=0.011). At the end of incubated days, the pH changed but not significantly different. LSD showed the significant differences between scaffold (5:5 and 4:6) with control and no significant difference between 2 concentrations of the scaffold. The conclusion of this study is the synthetic coral scaffold degraded gradually until the end incubation time and between concentration had different degradation profile in the early incubation time using pH measurement.<br></p>

Synthetic Materials for Osteochondral Tissue Engineering.

The objective of an articular cartilage repair treatment is to repair the affected surface of an articular joint's hyaline cartilage. Currently, both biological and tissue engineering research is concerned with discovering the clues needed to stimulate cells to regenerate tissues and organs totally or partially. The latest findings on nanotechnology advances along with the processability of synthetic biomaterials have succeeded in creating a new range of materials to develop into the desired biological responses to the cellular level. 3D printing has a great ability to establish functional tissues or organs to cure or replace abnormal and necrotic tissue, providing a promising solution for serious tissue/organ failure. The 4D print process has the potential to continually revolutionize the current tissue and organ manufacturing platforms. A new active research area is the development of intelligent materials with high biocompatibility to suit 4D printing technology. As various researchers and tissue engineers have demonstrated, the role of growth factors in tissue engineering for repairing osteochondral and cartilage defects is a very important one. Following animal testing, cell-assisted and growth-factor scaffolds produced much better results, while growth-free scaffolds showed a much lower rate of healing.

ID: 1045 Oxygen carrier containing microparticles for prolonged cell survival and effective bone regeneration

The organ transplantation is considered as an effective therapeutic method for organ failure. However, the shortage of donor organ and the immunological rejection are still remained as a big huddle in clinical fields. As an alternative, the tissue-engineering approach for functional organ replacement is extensively studied. The 3D porous scaffolds which guide growth and differentiation of cells are widely utilized as a vital factor with autologotic cells and growth factors for tissue engineering. However, cell necrosis in the center of 3D cell scaffold, due to the insufficient oxygen diffusion is considered as critical limitation for the formation of 3D tissues. Recently, various oxygen delivering/releasing materials have been studied to overcome this limitation. In this study, we developed a perfluorooctane (PFO)-loaded hollow microparticles (PFO-HP) which can allow sustained oxygen delivery for sufficient period, and thus provide appropriate environment for cell survival even in hypoxia. Cell (human periosteum-derived cell, hPDC) behaviors (proliferation, apoptosis, protein synthesis, etc.) in hypoxia (1% O2 and 5% CO2) were evaluated for 28 days. And osteogenic differentiation of cell [alkaline phosphatase (ALP activity), calcium deposition, immunocytochemistry, and RT-PCR (RUNX2, collagen type Ⅰ, osteocalcin, osteonectin)] after 10 days exposure in hypoxic condition was also investigated. New bone formation (histology, CT) of the cell-loaded PFO-HP and PBS-HP was also investigated using a miniature pig (mandibular defect model).

Culture Methods and Choice of Cells Makes a Difference in Outcome of Tissue Engineering- a Perspective

This perspective reviews the effects of different tissue engineering techniques, for induced differentiation of human embryonic stem cells into pulmonary lineage specific cells, and validating cell based regenerative therapy to ameliorate pulmonary degeneration. The etiology of degeneration differs from disease to disease. Likewise, strategies to regenerate lost tissues in its heterogeneity, should also cater to the regeneration process. To customize the same, researchers ought to device strategies to repair, replace or regenerate, in the spatio- temporal format, healthy tissues in their heterogeneous multi-functional existence, such that when transplanted in vitro, they may find their niche and integrate seamlessly into the tissue system and manifest full-fledged functional competence in order to reverse the erstwhile effects of degeneration. Cell based lung repair or regeneration is unquestionably the most promising agenda of regenerative medicine. In one of our studies, human embryonic stem cell (hESC) line H7 was successfully differentiated into three non-ciliated alveolar epithelial cells. In another study, BJNhem19 and BJNhem20 stem cell lines were used to induce similar guided endodermal differentiation into pulmonary lineage cells. Both studies were done using similar protocols, where the hESCs were first plated on gamma irradiated mouse embryonic fibroblast (MEF) feeder cells and undifferentiated hESCs were taken through embroid body formation. They were then subjected to induction into lung specific cells, by defined growth factors in Small Airways Growth Medium (SAGM) and Bronchiolar Endothelial Growth Media (BEGM). The H7 cells were found to express, both intracellularly and on their surfaces, characteristic marker proteins. However, the BJNhem19 and BJNhem20 cells showed poor differential potential, and could not be successfully differentiated into lung- specific cells. This difference in differentiation potential may be due to several intrinsic limitations, like genetic heterogeneity, anomalous morphogen receptivity or dormant/ unresponsive cytoplasmic determinants. These observations indicate that the choice of cells may play an important factor in tissue engineering. This review addresses the different culture methods and conditions needed for guided differentiation of stem cells. This perspective also discusses culture conditions of mesenchymal stem cells from different origins and dendritic stem cells from bone marrow.