The TE continues to develop and forms the extraembryonic support structures needed for the successful origin of the embryo, such as the placenta. Blastocysts are responsible for the regulation of the ICM microenvironment. Blastocysts are composed of two distinct cell types: the inner cell mass (ICM), which develops into epiblasts and induces the development of a foetus, and the trophectoderm (TE). Its inner wall is lined with short-lived stem cells, namely, embryonic stem cells. dermatocytes.Ī blastocyst is formed after the fusion of sperm and ovum fertilization. These cells are only able to form one cell type, e.g. Their latter feature makes them a promising candidate for therapeutic use in regenerative medicine. Unipotent stem cells are characterized by the narrowest differentiation capabilities and a special property of dividing repeatedly. A myeloid stem cell is an example that can divide into white blood cells but not red blood cells. Oligopotent stem cells can differentiate into several cell types. However, some multipotent cells are capable of conversion into unrelated cell types, which suggests naming them pluripotent cells.

Its differentiation abilities are then restricted to cells of its lineage. After differentiation, a haematopoietic stem cell becomes an oligopotent cell. One example is a haematopoietic stem cell, which can develop into several types of blood cells. Multipotent stem cells have a narrower spectrum of differentiation than PSCs, but they can specialize in discrete cells of specific cell lineages. Their culturing and utilization are very promising for present and future regenerative medicine. iPSCs are artificially generated from somatic cells, and they function similarly to PSCs. One of the methods to assess their activity and spectrum is the teratoma formation assay. Their pluripotency is a continuum, starting from completely pluripotent cells such as ESCs and iPSCs and ending on representatives with less potency-multi-, oligo- or unipotent cells. Another example is induced pluripotent stem cells (iPSCs) derived from the epiblast layer of implanted embryos. ESCs are derived from the inner cell mass of preimplantation embryos. Embryonic stem cells (ESCs) are an example. Pluripotent stem cells (PSCs) form cells of all germ layers but not extraembryonic structures, such as the placenta. This structure is the source of pluripotent cells. After approximately 4 days, the blastocyst’s inner cell mass becomes pluripotent. These cells can later develop either into any of the three germ layers or form a placenta. One example of a totipotent cell is a zygote, which is formed after a sperm fertilizes an egg. Totipotency has the highest differentiation potential and allows cells to form both embryo and extra-embryonic structures.

Totipotent stem cells are able to divide and differentiate into cells of the whole organism. This chapter will focus on stem cell classification to make it easier for the reader to comprehend the following chapters. Developmental potency is reduced with each step, which means that a unipotent stem cell is not able to differentiate into as many types of cells as a pluripotent one. There are several steps of specialization. Stem cells exist both in embryos and adult cells. They are able to differentiate into any cell of an organism and have the ability of self-renewal. Stem cells are unspecialized cells of the human body. A wide variety of possibilities makes this cutting edge therapy a turning point in modern medicine, providing hope for untreatable diseases. The review is summarized by challenges that stem cell therapy must overcome to be accepted worldwide. Among many types of stem tissue applications, the use of graphene scaffolds and the potential of extracellular vesicle-based therapies require attention due to their versatility. Derivation methods and the utilization of culturing media are crucial to set proper environmental conditions for controlled differentiation. Quality control and teratoma formation assays are important procedures in assessing the properties of the stem cells tested. The genesis of stem cells is followed by laboratory steps of controlled stem cell culturing and derivation.

This paper is a review focused on the discovery of different stem cells and the potential therapies based on these cells. The development of treatment methods has evoked great expectations. In recent years, stem cell therapy has become a very promising and advanced scientific research topic.

Pluripotent and totipotent