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The applications of stem cells in tissue engineering will show great promise in generating tailor-made tissue/organs for clinical applications. This paper gives a review on a broad spectrum of areas in stem cell-based tissue engineering including neuron repair, cardiac patches, skin regeneration, gene therapy and cartilage tissue engineering. This paper is intended to serve as an informative tutorial for scientists and physicians from fields other than stem cells and tissue engineering. It will shed light on various strategies of target tissue/organ repair involving stem cells.

Incidence and mortality of liver disease has increased globally in recent years. Orthotopic liver transplantation is a well-developed, effective therapy even for the end-stage liver diseases. However, the application of the technique is limited by the short supply of donors and the complexity of orthotopic liver transplantation. Therefore, hepatocyte transplantation as a new therapeutic option was developed. Unfortunately, the routine supply of high quality human hepatocytes was also restricted and the liver donor was lacking, too. Thus, exploration and study for available and renewable sources of nondonor hepatocytes are both necessary and important. Researches have proved that nondonor hepatocyte-like cells can be derived from various types of cells including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), liver stem cells (LSCs), fibroblasts by lineage reprogramming, hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). In this review, we describe recent advances in the field of the cell therapy in liver regeneration. In addition, we also discuss the existing restrictions in these types of therapies and ongoing developments.

Stem cells possess great potential for tissue regeneration due to their infrequent capability to differentiate into specialized some other cell lines. The progress of nanomaterials has been remarkable in recent years. Nanomaterials control cellular response by endocytosis, acting as scaffolding roles or nanocarriers and regulating extracellular matrix (ECM). Furthermore, some nanomaterials have outstanding optical and magnetic properties, so can be used for stem cells labeling and imaging which plays an essential role in defining the mechanisms governing stem-cells therapeutics. In this review, focus is put on recent developments in controlling the fate of stem cells and stem cells labeling and imaging by nanomaterials. The effect of nanomaterials based inorganic nanomaterials (e.g., carbon nanotubes, mesoporous silica nanoparticles, gold nanoparticles, etc.), organic materials (nanoscale topography), on the differentiation of mesenchymal stem cells, embryonic stem cells and cancer stem cells will be discussed. Optical imaging (fluorescence and up-conversion luminescence), magnetic resonance imaging and multimodal imaging by nanomaterials of stem cells will also be introduced.

Stem cell therapy is being developed as a promising novel strategy for the treatment of heart-associated diseases. Several types of cells such as skeletal myoblasts, bone marrow (BM) mesenchymal stem cells (MSCs), endothelial progenitor cells (EPCs), adipose stem cells (ADSCs), cardiac progenitor cells (CPCs), induced pluripotent stem cells (iPSCs) have been tested in pre-clinical and clinical cardiac repairing models. Fibroblasts, as terminally differentiated cells, could also be trans-differentiated into cardiomyocytes in vitro. In this review, we will summarize the recent advances of cell types, potential applications and challenges of stem cell therapy in the treatment of heart failure.

Stem cell therapy has been tested for cardiac disease therapy for decades. Initially, researchers only considered stem cells’ differentiative ability to repair damaged cardiac tissue. However, studies have now uncovered novel mechanisms contributing to stem cell healing properties to repair injured cardiac tissue, including via paracrine signaling and exosome secretions, leading to amelioration of cardiac remodeling and enhancement of proliferation, regeneration and survival of stem cell-derived cardiac cells. Understanding these underlying mechanisms could help researchers utilize stem cells as a therapeutic strategy for cardiac disease effectively and address the current limitations, mainly surrounding its survival and differentiative ability in the cardiac milieu. This review will discuss the known potential mechanisms underlying the role of stem cells in contributing to and for the treatment of heart diseases.

Tissue engineering strategies for regenerating damaged cartilage using hydrogels have garnered significant attention due to the limited self-healing capacity of damaged cartilage tissue and the restrictions of current medical treatment methods. In particular, using human mesenchymal stem cells (hMSCs) as the cell source has shown the potential to differentiate along a chondrogenic lineage. Hydrogels, whether made of synthetic polymers, natural polymers, or combinations, are widely explored as scaffolding materials mimicking the natural cartilage environment. Based on the understanding of the importance of surface nanotopographies and mechanical stiffness, hydrogels have been presented in various forms and tested for the differentiation of hMSCs. The primary focus of this review is to provide a summary of recent advances in physically and chemically modified hydrogels promoting the chondrogenesis of hMSCs. Advances in micromachining have helped in forming surfaces with the required roughness or an array of micropillars of defined architecture. Hydrogels have been combined with various stimulants such as small peptides, growth factors, and many modified matrix elements. Creating anisotropic hydrogels mimicking the extracellular matrix of cartilage has also been reported. These studies show promising results and identify a niche for in-vitro differentiation of chondrocytes from hMSCs.