Engineering Human Brain Organoids: From Basic Research to Tissue Regeneration

Background: Brain organoids are self-organized from human pluripotent stem cells and developed into various brain region following the developmental process of brain. Brain organoids provide promising approach for studying brain development process and neurological diseases and for tissue regeneration. Methods: In this review, we summarized the development of brain organoids technology, potential applications focusing on disease modeling for regeneration medicine, and multidisciplinary approaches to overcome current limitations of the technology. Results: Generations of brain organoids are categorized into two major classes by depending on the patterning method. In order to guide the differentiation into specific brain region, the extrinsic factors such as growth factors, small molecules, and biomaterials are actively studied. For better modelling of diseases with brain organoids and clinical application for tissue regeneration, improvement of the brain organoid maturation is one of the most important steps. Conclusion: Brain organoids have potential to develop into an innovative platform for pharmacological studies and tissue engineering. However, they are not identical replicas of their in vivo counterpart and there are still a lot of limitations to move forward to clinical applications

Discrete Dislocation Dynamics Simulations of Irradiation Hardening in Nuclear Materials

Neutron irradiation can severely impact the mechanical behavior of nuclear structural materials. Irradiation introduces a high density of nanometric defects that block dislocation motion and result in hardening and a loss of ductility often associated with the onset of localized plastic flow in a highly heterogeneous manner. In our hierarchy of numerical methods used to understand and quantify mechanical property degradation under irradiation, discrete dislocation dynamics (DD) provides a window into the time and length scales where critical interactions between dislocations and defects occur. In the present chapter, we discuss the current state of the art of DD simulations applied to irradiation scenarios, introducing the theoretical models devised to deal with dislocation-defect interactions, crystal structure particularities, and the most salient aspects of several highlighted applications. We also discuss current limitations and what new understanding has been gained vis-a-vis serviceable nuclear materials using these techniques