Therapeutic strategies of three-dimensional stem cell spheroids and organoids for tissue repair and regeneration

Three-dimensional(3D)stem cell culture systems have attracted considerable attention as a way to better mimic the complex interactions between individual cells and the extracellular matrix(ECM)that occur in vivo.Moreover,3D cell culture systems have unique properties that help guide specific functions,growth,and processes of stem cells(e.g.,embryogenesis,morphogenesis,and organogenesis).Thus,3D stem cell culture systems that mimic in vivo environments enable basic research about various tissues and organs.In this review,we focus on the advanced therapeutic applications of stem cell-based 3D culture systems generated using different engineering techniques.Specifically,we summarize the historical advancements of 3D cell culture systems and discuss the therapeutic applications of stem cell-based spheroids and organoids,including engineering techniques for tissue repair and regeneration.

Bioinspired magnetic cilia:from materials to applications

Microscale and nanoscale cilia are ubiquitous in natural systems where they serve diverse biological functions.Bioinspired artificial magnetic cilia have emerged as a highly promising technology with vast potential applications,ranging from soft robotics to highly precise sensors.In this review,we comprehensively discuss the roles of cilia in nature and the various types of magnetic particles utilized in magnetic cilia;additionally,we explore the top-down and bottom-up fabrication techniques employed for their production.Furthermore,we examine the various applications of magnetic cilia,including their use in soft robotics,droplet and particle control systems,fluidics,optical devices,and sensors.Finally,we present our conclusions and the future outlook for magnetic cilia research and development,including the challenges that need to be overcome and the potential for further integration with emerging technologies.

Bioprinting Methods for Fabricating In Vitro Tubular Blood Vessel Models

Dysfunctional blood vessels are implicated in various diseases,including cardiovascular diseases,neurodegenerative diseases,and cancer.Several studies have attempted to prevent and treat vascular diseases and understand interactions between these diseases and blood vessels across different organs and tissues.Initial studies were conducted using 2-dimensional(2D)in vitro and animal models.However,these models have difficulties in mimicking the 3D microenvironment in human,simulating kinetics related to cell activities,and replicating human pathophysiology;in addition,3D models involve remarkably high costs.Thus,in vitro bioengineered models(BMs)have recently gained attention.BMs created through biofabrication based on tissue engineering and regenerative medicine are breakthrough models that can overcome limitations of 2D and animal models.They can also simulate the natural microenvironment in a patient-and target-specific manner.In this review,we will introduce 3D bioprinting methods for fabricating bioengineered blood vessel models,which can serve as the basis for treating and preventing various vascular diseases.Additionally,we will describe possible advancements from tubular to vascular models.Last,we will discuss specific applications,limitations,and future perspectives of fabricated BMs.

Photodeposited metal-semiconductor nanocomposites and their applications

While two-dimensional layered nanomaterials including transition metal oxides and transition metal dichalcogenides have been widely researched because of their unique electronic and optical properties,they still have some limitations.To overcome these limitations,transition metal oxides and transition metal dichalcogenides based nanocomposites have been developed using various methods and have exhibited superior properties.In this paper,we introduce the photodeposition method and review the photodeposition of metal nanoparticles on the surface of transition metal oxide and transition metal dichalcogenides.Their current applications are also explained,such as photocatalysis,hydrogen evolution reaction,surface enhanced Ramanscattering,etc.This approach for nanocomposites has potential for future research areas such as photocatalysis,hydrogen evolution reaction,surface enhanced Raman scattering,and other applications.This approach for nanocomposite has the potential for future research areas.