Stem cells in three-dimensional bioprinting: Future perspectives

Abstract

Three-dimensional (3D) bioprinting is a new technology used to create biological constructs, widening the scope of regenerative and therapeutic medicine. Stem cells are self-renewing, remain undifferentiated unless stimulated and have the capability to differentiate into all specialized cell types. These characteristics make stem cells ideal for use in the production of 3D printed constructs. A biological construct is composed of cells in a scaffold that is compatible, biomimics and can integrate in vivo. Biological structures generated using 3D bioprinting have the potential to alleviate the need for donor tissue and organs for transplantation. Additionally, these constructs also provide a better way to model disease and test pharmaceuticals.

The Role of the Microenvironment in Controlling the Fate of Bioprinted Stem Cells

“…While many cell types can be utilized in bioprinting 3D tissue constructs, there are certain stem cell types that have been highly preferential in this application. These include, but are not limited to, ESCs, iPSCs, and adult stem cells . These cell types are frequently utilized due to their pluripotency and their ability to replicate in an undifferentiated fashion.…”

“…ESCs are often obtained from the blastocyst stage of an embryo and are undifferentiated. , Their pluripotency makes them ideal for stem cell bioprinting, as well as their ability to self-renew in an undifferentiated fashion which can later be guided to direct the cells toward a specific phenotype. , The major limitations of using ESCs in bioprinting efforts is their tendency to form teratomas, possible host immune response, leading to rejection and ethical concerns surrounding stem cell harvesting from embryos. ,− As ESCs can differentiate into virtually any cell in the body, they are an attractive option for bioprinted constructs. Depending on which state the research occurs in and their laws and regulations surrounding the use of fetal and embryonic stem cells, this may or may not be a feasible option in studies, especially for therapeutic applications.…”

“…With many similarities in differentiation potential to ESCs, iPSCs offer pluripotency and are derived from somatic cells. , This overcomes some of the issues surrounding the ethical use of stem cells derived from embryonic material . These cells are more plentiful and readily derived from many areas in the body, however, differentiation methods may be difficult or lead to cellular malformations and teratoma formation. , Because of federal and state regulations on the utilization of embryonic and fetal cells in research, iPSCs are currently a very popular avenue for stem cell research.…”

Three-Dimensional Bioprinting of Cartilage by the Use of Stem Cells: A Strategy to Improve Regeneration

“…Stem cells seem to be good candidates for cartilage bioprinting due to their already described properties [ 11 , 12 , 93 ], but there are some limitations. A main issue is represented by the regenerative ability towards the desired cartilage phenotype (hyaline or fibrous), and thus a functional tissue.…”

“…A main issue is represented by the regenerative ability towards the desired cartilage phenotype (hyaline or fibrous), and thus a functional tissue. For instance, MSCs display the tendency to progress into a hypertrophic phenotype and thus giving rise to endochondral bone formation [ 11 , 12 , 93 ]. Therefore, the search for more effective approaches avoiding hypertrophy is demanding.…”