Comparison of osteogenic differentiation potential of induced pluripotent stem cells on 2D and 3D polyvinylidene fluoride scaffolds

Structural Functions of 3D-Printed Polymer Scaffolds in Regulating Cell Fates and Behaviors for Repairing Bone and Nerve Injuries

Tissue repair and regeneration, such as bone and nerve restoration, face significant challenges due to strict regulations within the immune microenvironment, stem cell differentiation, and key cell behaviors. The development of 3D scaffolds is identified as a promising approach to address these issues via the efficiently structural regulations on cell fates and behaviors. In particular, 3D-printed polymer scaffolds with diverse micro-/nanostructures offer a great potential for mimicking the structures of tissue. Consequently, they are foreseen as promissing pathways for regulating cell fates, including cell phenotype, differentiation of stem cells, as well as the migration and the proliferation of key cells, thereby facilitating tissue repairs and regenerations. Herein, the roles of structural functions of 3D-printed polymer scaffolds in regulating the fates and behaviors of numerous cells related to tissue repair and regeneration, along with their specific influences are highlighted. Additionally, the challenges and outlooks associated with 3D-printed polymer scaffolds with various structures for modulating cell fates are also discussed.

Structure-optimized and microenvironment-inspired nanocomposite biomaterials in bone tissue engineering

Critical-sized bone defects represent a significant clinical challenge due to their inability to undergo spontaneous regeneration, necessitating graft interventions for effective treatment. The development of tissue-engineered scaffolds and regenerative medicine has made bone tissue engineering a highly viable treatment for bone defects. The physical and biological properties of nanocomposite biomaterials, which have optimized structures and the ability to simulate the regenerative microenvironment of bone, are promising for application in the field of tissue engineering. These biomaterials offer distinct advantages over traditional materials by facilitating cellular adhesion and proliferation, maintaining excellent osteoconductivity and biocompatibility, enabling precise control of degradation rates, and enhancing mechanical properties. Importantly, they can simulate the natural structure of bone tissue, including the specific microenvironment, which is crucial for promoting the repair and regeneration of bone defects. This manuscript provides a comprehensive review of the recent research developments and applications of structure-optimized and microenvironment-inspired nanocomposite biomaterials in bone tissue engineering. This review focuses on the properties and advantages these materials offer for bone repair and tissue regeneration, summarizing the latest progress in the application of nanocomposite biomaterials for bone tissue engineering and highlighting the challenges and future perspectives in the field. Through this analysis, the paper aims to underscore the promising potential of nanocomposite biomaterials in bone tissue engineering, contributing to the informed design and strategic planning of next-generation biomaterials for regenerative medicine.

Scaffold-Based Poly(Vinylidene Fluoride) and Its Copolymers: Materials, Fabrication Methods, Applications, and Perspectives

Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.

Effect of exogenous genistein on osteogenic differentiation of adipose-derived mesenchymal stem cells in laying hens

Previous literature revealed that genistein might play a preventive role in osteoporosis. Therefore, we aimed to evaluate the effect of genistein on the osteogenic potency of laying hens' adipose-derived stem cells (LHASCs). The viability of LHASCs after isolation was investigated on tissue culture plastic (TCP) under exposure to genistein up to 50 μg/mL by MTT assay. Our preliminary result revealed that LHASCs cultured under genistein exposure up to 20 μg/mL are feasible. Then, we evaluated the osteogenic induction of LHASCs under exposure to 0, 10, and 20 μg/mL genistein. The Alizarin Red staining confirmed the calcium deposition. Our findings showed that osteogenic differentiation under exposure to 20 μg/mL genistein led to higher ALP activity and more calcium content. We then tried to see the probable additive effect of the genistein-plus Poly-L-lactic acid (PLLA) scaffold on the cell viability and osteogenic capacity of LHASCs. For this, cells were cultured on a PLLA scaffold and exposed to 20 μg/mL genistein. Cell growth rate, as indicated by the MTT assay, revealed no differences between the groups. LHASCs cultured on a genistein-plus PLLA scaffold showed higher ALP activity and more calcium content. The expressions of Osteocalcin, COL1A2, ALP, and Runx2 genes were increased in the genistein-plus PLLA group as compared with PLLA and TCP groups. Adequate proliferation rates and higher expression of osteogenic markers provide genistein as a suitable substrate to support the proliferation and differentiation of LHASCs. Genistein supports osteogenic induction as a further positive effect if such a PLLA scaffold is available.

Polycaprolactone/poly L-lactic acid nanofibrous scaffold improves osteogenic differentiation of the amniotic fluid-derived stem cells

Using stem cells is one of the most important determining factors in repairing lesions using regenerative medicine. Obtaining adult stem cells from patients is a perfect choice, but it is worth noting that their differentiation and proliferation potential decreases as the patient ages. For this reason, the use of amniotic fluid stem cells can be one of the excellent alternatives. This research aimed to investigate the osteogenic differentiation potential of the amniotic fluid stem cells while cultured on the polycaprolactone/poly L-lactic acid nanofibrous scaffold. Scaffolds were qualitatively evaluated by a scanning electron microscope, and their hydrophilicity and mechanical properties were studied using contact angle and tensile test, respectively. The biocompatibility and non-toxicity of the nanofibers were also evaluated using viability assay. The osteo-supportive capacity of the nanofibers was examined using alizarin red staining, alkaline phosphatase activity, and calcium release measurement. Finally, the expression level of four important bone-related genes was determined quantitatively. The results demonstrated that the mineralization rate, alkaline phosphatase activity, intracellular calcium, and bone-related genes increased significantly in the cells cultured on the polycaprolactone/poly L-lactic acid scaffold compared to the cells cultured on the tissue culture plate as a control. According to the results, it can be concluded that the polycaprolactone/poly L-lactic acid nanofibrous scaffold surprisingly improved the osteogenic differentiation potential of the amniotic fluid stem cells and, in combination with polycaprolactone/poly L-lactic acid nanofibers could be a promising candidate as bone implants.

Smart and Multifunctional Materials Based on Electroactive Poly(vinylidene fluoride): Recent Advances and Opportunities in Sensors, Actuators, Energy, Environmental, and Biomedical Applications

From scientific and technological points of view, poly(vinylidene fluoride), PVDF, is one of the most exciting polymers due to its overall physicochemical characteristics. This polymer can crystalize into five crystalline phases and can be processed in the form of films, fibers, membranes, and specific microstructures, being the physical properties controllable over a wide range through appropriate chemical modifications. Moreover, PVDF-based materials are characterized by excellent chemical, mechanical, thermal, and radiation resistance, and for their outstanding electroactive properties, including high dielectric, piezoelectric, pyroelectric, and ferroelectric response, being the best among polymer systems and thus noteworthy for an increasing number of technologies. This review summarizes and critically discusses the latest advances in PVDF and its copolymers, composites, and blends, including their main characteristics and processability, together with their tailorability and implementation in areas including sensors, actuators, energy harvesting and storage devices, environmental membranes, microfluidic, tissue engineering, and antimicrobial applications. The main conclusions, challenges and future trends concerning materials and application areas are also presented.

Generation of glucose sensitive insulin-secreting cells from human induced pluripotent stem cells on optimized polyethersulfone hybrid nanofibrous scaffold

BACKGROUND

In the realm of diabetes treatment, various strategies have been tried, including islet transplantation and common drug therapies, but the limitations of these procedures and lack of responsive to the high number of patients have prompted researchers to develop a new method. In recent decades, the use of stem cells and three-dimonsional (3D) scaffold to produce insulin-secreting cells is one of the most promising new approaches. Meanwhile, human-induced pluripotent stem cells (iPSCs) propose due to advantages such as autologousness and high pluripotency in cell therapy. This study aimed to evaluate the differentiation of iPSCs into pancreatic islet insuli-producing cells (IPCs) on Silk/PES (polyethersulfone) nanofibers as a 3D scaffold and compare it with a two-dimonsional (2D) cultured group.

METHODS

Investigating the functional, morphological, molecular, and cellular characteristics of differentiated iPSCs on control cultures (without differentiation medium), 2D and 3D were measured by various methods such as electron microscopy, Q-PCR, immunofluorescence, western blot, and ELISA.

RESULTS

This investigation revealed that differentiated cells on the 3D Silk/PES scaffold expressed pancreatic specific-markers such as insulin and pdx1 at higher levels than the control and 2D groups, with a significant difference between the two groups. All results of Q-PCR, immunocytochemistry, and western blot showed that IPCs in the silk/PES 3D group was more efficient than in the 2D group. In the face of these cases, the release of insulin and C-peptide in response to several concentrations of glucose in the 3D group was significantly higher than in the 2D culture.

CONCLUSION

Finally, our findings displayed that optimized Silk/PES 3D scaffolds can enhance the differentiation of IPCs from iPSCs compared to the 2D culture group.

Engineering Dental Tissues Using Biomaterials with Piezoelectric Effect: Current Progress and Future Perspectives

Dental caries and traumatic injuries to teeth may cause irreversible inflammation and eventual death of the dental pulp. Nevertheless, predictably, repair and regeneration of the dentin-pulp complex remain a formidable challenge. In recent years, smart multifunctional materials with antimicrobial, anti-inflammatory, and pro-regenerative properties have emerged as promising approaches to meet this critical clinical need. As a unique class of smart materials, piezoelectric materials have an unprecedented advantage over other stimuli-responsive materials due to their inherent capability to generate electric charges, which have been shown to facilitate both antimicrobial action and tissue regeneration. Nonetheless, studies on piezoelectric biomaterials in the repair and regeneration of the dentin-pulp complex remain limited. In this review, we summarize the biomedical applications of piezoelectric biomaterials in dental applications and elucidate the underlying molecular mechanisms contributing to the biological effect of piezoelectricity. Moreover, we highlight how this state-of-the-art can be further exploited in the future for dental tissue engineering.

Synthetic electrospun nanofibers as a supportive matrix in osteogenic differentiation of induced pluripotent stem cells

Continuous remodeling is not able to repair large bone defects. Bone tissue engineering is aimed to repair these defects by creating bone grafts. To do this, several technologies and biomaterials have been employed to fabricate an in vivo-like supportive matrix. Electrospinning is a versatile technique to fabricate porous matrices with interconnected pores and high surface area, replicating in vivo microenvironment. Electrospun scaffolds have been used in a large number of studies to provide a matrix for bone regeneration and osteogenic differentiation of stem cells such as induced pluripotent stem cells (iPSCs). Electrospinning uses both natural and synthetic polymers, either alone or in combination, to fabricate scaffolds. Among them, synthetic polymers have had a great promise in bone regeneration and repair. They allow the fabrication of biocompatible and biodegradable scaffolds with high mechanical properties, suitable for bone engineering. Furthermore, several attempts have done to increase the osteogenic properties of these scaffolds. This paper reviewed the potential of synthetic electrospun scaffolds in osteogenic differentiation of iPSCs. In addition, the approaches to improve the osteogenic differentiation of these scaffolds are addressed.

Comparative review of piezoelectric biomaterials approach for bone tissue engineering

Bone as a minerals' reservoir and rigid tissue of the body generating red and white blood cells supports various organs. Although the self-regeneration property of bone, it cannot regenerate spontaneously in severe damages and still remains as a challenging issue. Tissue engineering offers several techniques for regenerating damaged bones, where various biomaterials are examined to fabricate scaffolds for bone repair. Piezoelectric characteristic plays a crucial role in repairing and regenerating damaged bone by mimicking the bone niche behavior. Piezoelectric biomaterials show significant potential for bone tissue engineering. Herein we try to have a comparative review on piezoelectric and non-piezoelectric biomaterials used in bone tissue engineering, classified them, and discussed their effects on implanted cells and manufacturing techniques. Especially, Polyvinylidene fluoride (PVDF) and its composites are the most practically used piezoelectric biomaterials for bone regeneration. PVDF and its composites have been summarized and discussed to repair damaged bone tissues.

Bioinspired All-in-One Three-Dimensional Dynamic CellMatrix Improves the Manufacture of Therapeutically Qualified Cells for Cell Therapy

Despite the great promise, cell therapy still faces practical challenges because of the scarcity of a reliable cell source. Herein, a bioinspired 3D dynamic culture system (CellMatrix) with rational structure, composite and function, was developed for improving cell supply. CellMatrix was composed of unique core-shell fibers with a core of black phosphorus-incorporated fibroin and a shell of sericin, which together formed a 3D silkworm cocoon-mimicking structure via a bottom-up fabrication technique. CellMatrix not only provided optimal engineered biomimetic niche to facilitate cell growth but exhibited good photothermal conversion to dynamically regulate cell fates. Importantly, cell-CellMatrix construct could be directly implanted into defected tissues and improved tissue remodeling. Meanwhile, CellMatrix displayed good ice resistance and thermal conductivity, which maximally maintained cell viability and proliferation after the freeze-thawing process, allowing for storing precious cells and cell-CellMatrix construct. Thus, CellMatrix represents an all-in-one biomimetic platform for the culture-production-storage of therapeutically qualified cells.

A novel hybrid polymer of PCL/Fish gelatin nanofibrous scaffold improves proliferation and differentiation of wharton's jelly-derived mesenchymal cells into islet-like cells

BACKGROUND

Using a different source of stem cells to compensate for the lost beta cells is a promising way to cure diabetic patients. Besides The best efficiency of insulin-producing cells (IPCs) will appear when we culture them in an environment similar to inside the body. Hence, three-dimensional (3D) culture ameliorates the differentiation of diverse kinds of stem cells into IPCs compared to those differentiated in two-dimensional (2D) culture. In this study, we aim to create an ideal differentiation environment by using PCL/Fish gelatin nanofibrous scaffolds to differentiate wharton's jelly-derived mesenchymal cells (WJ-MSCs) to IPCs and compare them with a 2D cultured group.

METHODS

The evaluation of cellular, molecular, and functional properties of differentiated cells on the 3D and 2D cultures were investigated by several assay such as electron microscopy, quantitative PCR, immunochemistry, western blotting, and ELISA.

RESULTS

The in vitro studies showed, WJ-MSCs that differentiated in the 3D culture have strong properties of IPCs such as islet-like cells. The expression of pancreatic-specific genes at both RNA and protein levels showed higher differentiation efficacy of 3D culture. Besides, the results of the elisa tests demonstrates that in both groups the differentiated cells are functional and secreted C-peptide and insulin in glucose stimulation, but the secretion of C-peptide and insulin in the 3D culture group was higher than those cultured in 2D groups.

CONCLUSION

Our findings showed the use of PCL/Fish gelatin nanofibrous scaffolds with optimized differentiation protocols can promote the differentiation of IPCs from WJ-MSCs compared to the 2D culture group.

Improved biological behaviours and osteoinductive capacity of the gelatin nanofibers while composites with GO/MgO

Among the many polymers introduced for bone tissue engineering, natural polymers have more advantages due to their high biocompatibility and biodegradability, despite their low mechanical properties. Herein, gelatin nanofibers with and without magnesium oxide (MgO) and graphene oxide (GO) nanoparticles were fabricated by electrospinning. The fabricated gelatin and gelatin/GO/MgO nanofibers were examined using scanning electron microscopy, protein adsorption, cell attachment and viability assays. The results revealed that biological behaviours of the gelatin nanofibers significantly improved while incorporated with MgO and GO nanoparticles. In the following, osteosupportive capacity of the fabricated scaffolds was investigated by Alizarin-red staining, alkaline phosphatase activity, and calcium content, and bone-related gene and protein assays. The results revealed that the highest osteogenic differentiation potential of human-induced pluripotent stem cells (hiPSCs) was detected while these cells were cultured on the gelatin/GO/MgO nanofibers. However, these makers in the hiPSCs cultured on the gelatin nanofibers were also significantly increased in comparison with the cells cultured on the tissue culture plates as a control. In conclusion, the results revealed that predictable disadvantages in gelatin nanofibers can be greatly improved by the addition of MgO and GO nanoparticles, and the resulting composite scaffold could be a potential candidate for use in bone tissue engineering.

Photoactive 3D-Printed Hypertensile Metamaterials for Improving Dynamic Modeling of Stem Cells

Current three-dimensional (3D) cell culture systems mainly rely on static cell culture and lack the ability to thoroughly manage cell intrinsic behaviors and biological characteristics, leading to unsatisfied cell activity. Herein, we have developed photoactive 3D-printed hypertensile metamaterials based dynamic cell culture system (MetaFold) for guiding cell fate. MetaFold exhibited high elasticity and photothermal conversion efficiency due to its metapattern architecture and micro/nanoscale polydopamine coating, allowing for responding to mechanical and light stimulation to construct dynamic culture conditions. In addition, MetaFold possessed excellent cell adhesion capability and could promote cell viability and function under dynamic stimulation, thereby maximizing cell activity. Importantly, MetaFold could improve the differentiation efficacy of stem cells into cardiomyocytes and even their maturation, offering high-quality precious candidates for cell therapy. Therefore, we present a dual stimuli-responsive dynamic culture system, which provides a physiologically realistic environment for cell culture and biological study.

The role of natural polymers in bone tissue engineering

Bone is a dynamic self-healing organ and a continuous remodeling ensures the restoration of the bone structure and function over time. However, bone remodeling is not able to repair large traumatic injuries. Therefore, surgical interventions and bone substitutes are required. The aim of bone tissue engineering is to repair and regenerate tissues and engineered a bone graft as a bone substitute. To met this goal, several natural or synthetic polymers have been used to develop a biocompatible and biodegradable polymeric construct. Among the polymers, natural polymers have higher biocompatibility, excellent biodegradability, and no toxicity. So far, collagen, chitosan, gelatin, silk fibroin, alginate, cellulose, and starch, alone or in combination, have been widely used in bone tissue engineering. These polymers have been used as scaffolds, hydrogels, and micro-nanospheres. The functionalization of the polymer with growth factors and bioactive glasses increases the potential use of polymers for bone regeneration. As bone is a dynamic highly vascularized tissue, the vascularization of the polymeric scaffolds is vital for successful bone regeneration. Several in vivo and in vitro strategies have been used to vascularize the polymeric scaffolds. In this review, the application of the most commonly used natural polymers is discussed.

On the road to smart biomaterials for bone research: definitions, concepts, advances, and outlook

The demand for biomaterials that promote the repair, replacement, or restoration of hard and soft tissues continues to grow as the population ages. Traditionally, smart biomaterials have been thought as those that respond to stimuli. However, the continuous evolution of the field warrants a fresh look at the concept of smartness of biomaterials. This review presents a redefinition of the term "Smart Biomaterial" and discusses recent advances in and applications of smart biomaterials for hard tissue restoration and regeneration. To clarify the use of the term "smart biomaterials", we propose four degrees of smartness according to the level of interaction of the biomaterials with the bio-environment and the biological/cellular responses they elicit, defining these materials as inert, active, responsive, and autonomous. Then, we present an up-to-date survey of applications of smart biomaterials for hard tissues, based on the materials' responses (external and internal stimuli) and their use as immune-modulatory biomaterials. Finally, we discuss the limitations and obstacles to the translation from basic research (bench) to clinical utilization that is required for the development of clinically relevant applications of these technologies.

The use of mesenchymal stem cells in the process of treatment and tissue regeneration after recovery in patients with Covid-19

In addition to causing health concerns, the new coronavirus has been considered in the world with its unknown mechanism of physiopathogenesis and long-term effects after patient recovery. Pulmonary, renal, hepatic and cardiac complications have been reported so far. Beside the researchers' focus on finding vaccines and using conventional therapies, cell-based therapy might be an effective therapeutic strategy. The use of mesenchymal stem cells (MSCs) is one of the options due to their immunomodulatory properties and their proven effects in the treatment of many diseases. As MSCs are not infected with covid-19, there is evidence that it modulates the immune system and prevents the virus from clotting. Despite the beginning of numerous clinical trials in the use of mesenchymal stem cells, it is necessary to set a practical guideline that specifies items such as cell origin, number of cells, frequency of injection, injection site, etc.

Cabbage-derived three-dimensional cellulose scaffold-induced osteogenic differentiation of stem cells

Herbal-derived three-dimensional scaffolds have a unique structure that represents the natural cellular microenvironment and can be potentially used for tissue engineering applications. In the present study, cabbage (Cb) leaves were decellularized and then their characteristics, such as surface roughness, wettability, porosity, mechanical properties, and specific surface area, were investigated. After that, scaffold osteoinductivity was studied by bone-marrow-derived mesenchymal stem cells (BM-MSCs) osteogenic differentiation while growing on the decellularized Cb leaves. Cells mineralization, calcium secretion, alkaline phosphatase (ALP) activity, and expression levels of bone-related genes were determined during the differentiation process. Our results from the structural characterization of the scaffolds demonstrated that decellularized Cb leaves are good candidates for bone differentiation in terms of surface roughness, mechanical properties, and interconnected pores. Osteogenic differentiation evaluation of the BM-MSCs determined that the cell's ALP activity and mineralization were increased significantly while cultured on the decellularized Cb leaves compared to the cells cultured on the culture plate as a control. Besides, Runx2, ALP, collagen-1 (Col-I), and osteocalcin genes were expressed in cells cultured on decellularized Cb leaves significantly higher than cells cultured on the culture plate. Based on these results, it can be concluded that the decellularized Cb scaffold has great potential for promoting BM-MSCs proliferation and osteogenic differentiation.

Mimicking the electrophysiological microenvironment of bone tissue using electroactive materials to promote its regeneration

The process of bone tissue repair and regeneration is complex and requires a variety of physiological signals, including biochemical, electrical and mechanical signals, which collaborate to ensure functional recovery. The inherent piezoelectric properties of bone tissues can convert mechanical stimulation into electrical effects, which play significant roles in bone maturation, remodeling and reconstruction. Electroactive materials, including conductive materials, piezoelectric materials and electret materials, can simulate the physiological and electrical microenvironment of bone tissue, thereby promoting bone regeneration and reconstruction. In this paper, the structures and performances of different types of electroactive materials and their applications in the field of bone repair and regeneration are reviewed, particularly by providing the results from in vivo evaluations using various animal models. Their advantages and disadvantages as bone repair materials are discussed, and the methods for tuning their performances are also described, with the aim of providing an up-to-date account of the proposed topics.

Maintenance and differentiation of human ES cells on polyvinylidene fluoride scaffolds immobilized with a vitronectin-derived peptide

Polyvinylidene fluoride (PVDF) is biocompatible, easy to fabricate, and has piezoelectric properties; it has been used for many biomedical applications including stem cell engineering. However, long-term cultivation of human embryonic stem cells (hESCs) and their differentiation toward cardiac lineages on PVDF have not been investigated. Herein, PVDF nanoscaled membrane scaffolds were fabricated by electrospinning; a vitronectin-derived peptide-mussel adhesive protein fusion (VNm) was immobilized on the scaffolds. hESCs cultured on the VNm-coated PVDF scaffold (VNm-PVDF scaffold) were stably expanded for more than 10 passages while maintaining the expression of pluripotency markers and genomic integrity. Under cardiac differentiation conditions, hESCs on the VNm-PVDF scaffold generated more spontaneously beating colonies and showed the upregulation of cardiac-related genes, compared with those cultured on Matrigel and VNm alone. Thus, VNm-PVDF scaffolds may be suitable for the long-term culture of hESCs and their differentiation into cardiac cells, thus expanding their application in regenerative medicine.

Induced Pluripotent Stem Cells in Dental and Nondental Tissue Regeneration: A Review of an Unexploited Potential

Cell-based therapies currently represent the state of art for tissue regenerative treatment approaches for various diseases and disorders. Induced pluripotent stem cells (iPSCs), reprogrammed from adult somatic cells, using vectors carrying definite transcription factors, have manifested a breakthrough in regenerative medicine, relying on their pluripotent nature and ease of generation in large amounts from various dental and nondental tissues. In addition to their potential applications in regenerative medicine and dentistry, iPSCs can also be used in disease modeling and drug testing for personalized medicine. The current review discusses various techniques for the production of iPSC-derived osteogenic and odontogenic progenitors, the therapeutic applications of iPSCs, and their regenerative potential in vivo and in vitro. Through the present review, we aim to explore the potential applications of iPSCs in dental and nondental tissue regeneration and to highlight different protocols used for the generation of different tissues and cell lines from iPSCs.

Fucosylated umbilical cord blood hematopoietic stem cell expansion on selectin-coated scaffolds

Despite the advantages of transplantation of umbilical cord blood's (UCB's) hematopoietic stem cells (uHSCs) for hematologic malignancy treatment, there are two major challenges in using them: (a) Insufficient amount of uHSCs in a UCB unit; (b) a defect in uHSCs homing to bone marrow (BM) due to loose binding of their surface glycan ligands to BM's endothelium selectin receptors. To overcome these limitations, after poly l-lactic acid (PLLA) scaffold establishment and incubation of uHSCs with fucosyltransferase-VI and GDP-fucose, ex vivo expansion of these cells on selectin-coated scaffold was done. The characteristics of the cultured fucosylated and nonfucosylated cells on a two-dimensional culture system, PLLA, and a selectin-coated scaffold were evaluated by flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony-forming unit (CFU) assay, and CXCR4 expression at the messenger RNA and protein levels. According to the findings of this study, optimized attachment to the scaffold in scanning electron microscopy micrograph, maximum count of CFU, and the highest 570 nm absorption were observed in fucosylated cells expanded on selectin-coated scaffolds. Furthermore, real-time polymerase chain reaction showed the highest expression of the CXCR4 gene, and immunocytochemistry data confirmed that the CXCR4 protein was functional in this group compared with the other groups. Considered together, the results showed that selectin-coated scaffold could be a supportive structure for fucosylated uHSC expansion and homing by nanotopography. Fucosylated cells placed on the selectin-coated scaffold serve as a basal surface for cell-cell interaction and more homing potential of uHSCs. Accordingly, this procedure can also be considered as a promising technique for the hematological disorder treatment and tissue engineering applications.