Aging society, sports injuries, diseases, and the high demand for organs for transplantation contributes to looking for new strategies for people healing. Tissue engineering has been identified to fulfill this need and to respond to the challenges of the 21st century. Tissue engineering combines knowledge and achievements from material science, nanotechnology, cell biology, and medicine. Specific advancements that have benefited tissue engineering include novel biomaterials, fabrication of 3D scaffolds, and integration of technological achievements. The main goal of tissue engineering is to produce constructs that mimic native tissue for the regeneration of damaged tissues and organs. Usually, tissue engineering construct is composed of the scaffold, cells (e.g., stem cells), and biochemical factors/molecules (e.g., growth factors, cells differentiation molecules). The main goal of this construct is to replace, repair, or regenerate cells, tissues, and organs to restore normal function in the body.
Novel trends in tissue are so-called smart or stimuli-responsive biomaterials that can be designed to modulate their physical, chemical, and mechanical properties in response to changes in external stimuli or local physiological environment. These biomaterials can respond to a variety of physical, chemical, and biological cues such as temperature, sound, light, humidity, redox potential, pH, and enzyme activity. Other unique characteristics displayed by some smart biomaterials are self-healing or shape-memory behavior. The development of biomaterials with highly tunable properties has been driven by the desire to replicate the structure and function of an extracellular matrix (ECM). Such materials can enable the control of chemical and mechanical properties of the engineered tissue, including stiffness, porosity, cell attachment sites, and water uptake.
Another example is Fused Deposition Modeling (FDM), whose advancements are at the core of many developments in tissue engineering. Depending on the specific techniques, it is now possible to fabricate scaffolds made of polymers, ceramic, and metals. It is also possible to prepare hybrids or composites using a combination of components, sometimes with additive cells. Researchers are using synthetic and natural polymers, in the form of solids or hydrogels, in combination with cells and growth factors to get more complex 3D structures.