Many more deaths occurred thanks to less availability of organs and donors. Tissue engineering/ Regenerative medicine opens the trail to make and generate desired tissue, cells also as Organs in Vitro to fight against the limitation and to make a replacement hope within the field of transplantation to fill the damaged and missing body parts. While rehabilitation engineering helps to revive normal function. Spanning use of cell, pharmacological and bioengineering technologies, alongside physical modalities and exercise.

Stem cell microenvironment is the general term of the three-dimensional structure and a variety of signaling molecules (growth factors and their receptors, hormones and signaling molecules) present in the stroma where the stem cells reside and it can regulate the fate (proliferation/differentiation) of the stem cells.

Stem-cell research is the area of research that studies the properties of stem cells and their potential use in medicine. As stem cells are the source of all tissues, understanding their properties helps in our understanding of the healthy and diseased body's development and homeostasis.

The stem cell theory of aging postulates that the aging process is the result of the inability of various types of stem cells to continue to replenish the tissues of an organism with functional differentiated cells capable of maintaining that tissues (or organs) original function.

The use of convalescent plasma (CP) collected from previously infected individuals to passively transfer antibodies so as to guard or treat humans dates back almost 100 years. Results from small case series during the prior MERS and SARS coronavirus outbreaks suggested that CP is safe and should confer clinical benefits, including faster viral clearance, particularly when administered early within the disease course1. The overwhelming majority of patients who get over COVID-19 illness develop circulating antibodies to varied SARS-CoV-2 proteins 2-3 weeks following infection, which are detectable by ELISA or other quantitative assays and sometimes correlate with the presence of neutralizing antibodies.

Cells are the essential building blocks of all living things, and genes are often found deep within cells. Genes are small sections of DNA that carry genetic information and directions for creating proteins, which help build and maintain the body. Every person has around 20,000 genes and two copies of every of their genes—one from each parent. Small variations in genes end in differences in people’s appearance and, potentially, health. Genetic diseases happen when a critical piece or whole section of DNA is substituted, deleted or duplicated. These changes are called genetic mutations. Some serious genetic diseases caused by genetic mutations are often passed to future generations.

Cancers remain the lead cause of disease-related, pediatric death in North America. The emerging field of complex systems has redefined cancer networks as a computational system with intractable algorithmic complexity. Herein, a tumor and its heterogeneous phenotypes are discussed as dynamical systems having multiple, strange attractors. Machine learning, network science and algorithmic information dynamics are discussed as current tools for cancer network reconstruction. Deep Learning architectures and computational fluid models are proposed for better forecasting gene expression patterns in cancer ecosystems. Cancer cell decision-making is investigated within the framework of complex systems and complexity theory.

Stem cells constitute a source of self-renewing cells with a potential to differentiate into distinct tissues. In the embryo, these cells supply the multiple different cell lineages necessary to generate functional organs. Adult tissues retain somatic stem cells with capabilities for specific tissue turnover and repair. Embryonic and adult stem cell research has shown that stem cell fates are controlled by their specialized microenvironment, referred to as the stem cell niche, via direct cell-cell interactions and the molecular signals emitting from the niche.

Cancer Stem cells CSCs area unit rare timeless cells within a neoplasm which will hold the overall capability of a natural somatic cell with the flexibility of extremely proliferation and malignancy. They feed the neoplasm development associate degreed to border neoplasm and induce cancer in an organ. These extremely economical qualities of a cancer somatic cell area unit utilized in medication and therapeutic treatments in many diseases. Whereas medical specialty outline the study of nature, types, cause, interference and cure of cancer and neoplasm biology.

Bone marrow transplant (BMT) is a special therapy for patients with certain cancers or other diseases. A bone marrow transplant involves taking cells that are normally found in the bone marrow (stem cells), filtering those cells, and giving them back either to the donor (patient) or to another person.

The retinal pigment epithelium (RPE) is a single layer of post-mitotic cells, which functions both as a selective barrier to and a vegetative regulator of the overlying photoreceptor layer, thereby playing a key role in its maintenance. Through the expression and activity of specific proteins, it regulates the transport of nutrients and waste products to and from the retina, it contributes to outer segment renewal by ingesting and degrading the spent tips of photoreceptor outer segments, it protects the outer retina from excessive high-energy light and light-generated oxygen reactive species and maintains retinal homeostasis through the release of diffusible factors. The ageing characteristics of the RPE suggest that in addition to cell loss, pleomorphic changes and loss of intact melanin granules, significant metabolic changes occur resulting, at least in part, from the intracellular accumulation of lipofuscin. This pigment has been shown to be highly phototoxic and has been linked to several oxidative changes, some leading to cell death. While the etiology of age-related macular degeneration is complex and is as yet unresolved, it is likely that accelerated ageing-like changes in the RPE play a fundamental role in the development of this condition

Molecular genetics can be defined as “the use of recombinant DNA techniques to manipulate genetic information within and between plants, animals and microorganisms” to produce genetically modified organisms.

As explained Stem Cells area unit general cells that have the aptitude to totally differentiate in to different sort of cells and tissues that area unit the building blocks of body, that's completed by the tactic of regeneration and degeneration which can accustomed overcome the constraints of animal models in bound disorders. Similarly as in drug screening and drug discovery. Several methods area unit accustomed generate such sickness models exploitation either embryonic stem cells (ES cells) or patient-specific induced PSCs (iPSCs), that's making new era within the sector of sickness modeling and drug discovery.

Cells consist of cytoplasm enclosed within a membrane, which also contains many biomolecules such as proteins and nucleic acid. The number of cells in plants and animals varies from species to species, it has been estimated that humans contain somewhere around 40 trillion (4×1013) cells. Enclosing the cell is that the cell envelope – generally consisting of a cell membrane covered by a cell wall which, for a few bacteria, could also be further covered by a third layer called a capsule.