Question

1. You are working on tissue engineering cartilage in a bioreactor by seeding mesenchymal stem cells (MSCs) on a scaffold. a) What growth factor would you use to promote the MSC differentiation into chondrocytes? Fibroblast b) What are the advantages and disadvantages of directly injecting growth factors into the cell-seeded scaffold?

Answer 1

A. Fibroblast growth factor

b.

Growth factors have a significant role to play in successful bone tissue engineering scaffolds. The processes of new bone formation and extracellular matrix deposition are regulated by a range of growth factors and biomolecules. Bone morphogenic proteins (BMP) play a critical role in bone and cartilage development, and have the ability to trigger proliferation and differentiation of osteoprogenitor cells . There are several examples of scaffolds that have successfully incorporated BMPs resulting in improved bone formation.

shortage of donors, high cost, need for sterilization and activation and risk of viral disease transmission, bacterial infection or immune rejection [12]. The limitations and disadvantages associated with auto- and allograft harvesting point to the clinical need for alternative bone repair strategies. This has led to the development of bone tissue regeneration approaches such as bone tissue engineering

c.One of the most impressive technological advancements of the last decades is 3D printing .Most importantly is the printing of biological material directly onto scaffolds that could be seeded with cells . This is referred to as 3D bioprinting. 3D bioprinting involves different fields including material science, cell biology, and tissue engineering .Successful bioprinting requires the proper placement of biological material, cells, and biomolecules such as growth factors. In order to mimic human tissue, 3D bioprinting must be able to capture the complex structure of the extracellular matrix (ECM) and the different cells present in different tissues .In addition, bioprinting must be able to recapitulate the vascular and nervous systems of each tissue needed. In this review, we discuss how recent advances in regenerative medicine and tissue engineering could improve 3D bioprinting and vice versa. We also provide the latest technological advances of 3D bioprinting of potential transplantable tissues and organs. Specifically, we focus on factors required for proper recapitulation of living tissues and organs and their mechanical characteristics and functions. We briefly discuss how this technological advancement is impacting the fabrication of cartilage, heart, and liver.