Hierarchical Composite Scaffold with Deferoxamine Delivery System to Promote Bone Regeneration via Optimizing Angiogenesis.

A bone defect refers to the loss of bone tissue caused by trauma or lesions. Bone defects result in high morbidity and deformity rates worldwide. Autologous bone grafting has been widely applied in clinics as the gold standard of treatment; however, it has limitations. Hence, bone tissue engineering (BTE) has been proposed and developed as a novel therapeutic strategy for treating bone defects. Rapid and effective vascularization is essential for bone regeneration. In this study, a hierarchical composite scaffold with deferoxamine (DFO) delivery system, DFO@GMs-pDA/PCL-HNTs (DGPN), was developed, focusing on vascularized bone regeneration. The hierarchical structure of DGPN imitates the microstructure of natural bone and interacts with the local extracellular matrix (ECM), facilitating cell adhesion and proliferation. The addition of 1 wt% of halloysite nanotubes (HNTs) improved the material properties. Hydrophilic and functional groups conferred by polydopamine (pDA) modifications strengthened the scaffold bioactivity. Gelatin microspheres (GMs) protected the pharmacological activity of DFO, achieving local application and sustained release for seven days. DFO effectively promoted angiogenesis by activating the signaling pathway of hypoxia inducible factor-1 α (HIF-1 α). In addition, DFO synergized with HNTs to promote osteogenic differentiation and matrix mineralization. These results indicated that DGPN promoted bone regeneration and accelerated cranial defect healing. This article is protected by copyright. All rights reserved.

Role of extracellular vesicles in nonalcoholic fatty liver disease.

Background: Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that affects approximately one-quarter of the global population and is becoming increasingly prevalent worldwide. The lack of current noninvasive tools and efficient treatment is recognized as a significant barrier to the clinical management of these conditions. Extracellular vesicles (EVs) are nanoscale vesicles released by various cells and deliver bioactive molecules to target cells, thereby mediating various processes, including the development of NAFLD. Scope of review: There is still a long way to actualize the application of EVs in NAFLD diagnosis and treatment. Herein, we summarize the roles of EVs in NAFLD and highlight their prospects for clinical application as a novel noninvasive diagnostic tool as well as a promising therapy for NAFLD, owing to their unique physiochemical characteristics. We summarize the literatures on the mechanisms by which EVs act as mediators of intercellular communication by regulating metabolism, insulin resistance, inflammation, immune response, intestinal microecology, and fibrosis in NAFLD. We also discuss future challenges that must be resolved to improve the therapeutic potential of EVs. Major conclusions: The levels and contents of EVs change dynamically at different stages of diseases and this phenomenon may be exploited for establishing sensitive stage-specific markers. EVs also have high application potential as drug delivery systems with low immunogenicity and high biocompatibility and can be easily engineered. Research on the mechanisms and clinical applications of EVs in NAFLD is in its initial phase and the applicability of EVs in NAFLD diagnosis and treatment is expected to grow with technological progress.

Designing Intergenerational Spaces: What to Learn From Children.

OBJECTIVES: Adopting recommendations of the United Nations Committee on the Rights of the Child, this study addresses the value of children's input on the architectural design of the built environment of intergenerational shared sites and the intergenerational interactions that took place there. BACKGROUND: Intergenerational programs bring children and older adults together, inviting them to interact, exchange ideas and support each other. Most intergenerational programs are planned by staff and often take place in a multipurpose room without direct input from child or older adult participants. METHODS: Data for this study were collected through interviews and drawings from 16 children at three intergenerational centers in Hawaii, Kansas, and Virginia. The interviews were transcribed, analyzed, coded, and categorized. Child development experts analyzed the drawings to better understand how children experience their surrounding environment. RESULTS: Four themes emerged from the triangulated data: (1) outdoor spaces offer rich opportunities for shared programming, (2) children enjoy sharing meals and snacks with intergenerational partners, (3) children recognize environmental features that facilitate or limit intergenerational interaction, and (4) varied spaces support to informal, brief intergenerational interaction. Our findings provide evidence in the value of involving children in designing intergenerational centers and programming. CONCLUSION: The children who participated in this study provided meaningful insight reflecting the experience of intergenerational activities and the impacts of the built environment on the quality and variety of these interactions.