Current Opinion in Biomedical Engineering最新文献

Osteochondral tissue represents a complex biochemical and biophysical gradient between two distinctly different types of tissue. Its poor regeneration capabilities necessitate tissue engineering intervention; however, its complex structure and composition pose an immense engineering challenge. Though bone and cartilage engineering separately have seen success, fabricating the graded interface between these two dissimilar tissue types requires understanding and collaboration between multiple often-disunited disciplines. This review showcases innovative tissue engineering strategies utilised for fabrication of osteochondral interfaces in an attempt to bridge this gap, and highlights the potential of biofabrication techniques – namely 3D bioprinting – in providing a path towards future advancement in osteochondral and interfacial tissue engineering.

Deriving from the mesoderm at mesenchymal condensation, in the nascent musculoskeletal system, interface tissues include periosteum, ligament, interosseous membrane, and joint capsules. They comprise common structural proteins, collagen, and elastin, woven into anisotropic composites with toughness and elasticity adapted to withstand prevailing dynamic loads. Together with their composite fibrous weave structure, the interface tissues' respective resident cells imbue unique properties to the tissues. For example, the progenitor cells of the periosteal cambium layer express claudin, a tight junction protein that confers anisotropic and smart functional barrier properties to the periosteal membrane; e.g. where permeability is higher in the muscle to bone direction than vice versa under high flow rates typical for trauma. This review compares properties of interface tissues, focusing on periosteum, the interosseous membrane (a specialized ligament structure), and the deep (investing) fascia. It highlights current gaps in understanding as well as opportunities to create and advance manufacture next generation medical textiles and devices that emulate interface tissue properties.

Trauma, both psychological and physical, represents a complex and pervasive challenge to individual well-being. This paper explores the dynamic interplay between mental and physical health in the context of trauma, shedding light on the processes of regeneration that occur at their interface. Drawing from a comprehensive review of basic, clinical and interdisciplinary research, this paper elucidates the bidirectional relationships between mental and physical health outcomes following traumatic experiences. Especially the influence of inflammation, gut microbiome, stress hormones and the activation of the HPA axis are explored in more detail. In conclusion, stress-related disorders and mental diseases should be taken into account when patients display a disturbed healing after physical injury. Awareness for the significant impact of mental health on trauma outcome should be increased among physicians.

Due to the high incidence of cartilage-related pathologies such as focal defects and osteoarthritis, strategies are needed to restore the structure and function of osteochondral tissue. Articular cartilage and bone have distinctly different properties, rendering challenging the engineering of a robust interface that reduces stress concentrations and delamination. The osteochondral interface, which consists of a tidemark, calcified cartilage, cement line, and surrounding tissues, has a unique structure and function, but there is a dearth of quantitative data to describe it. Elucidating the structure–function relationships through characterization will be essential in defining design criteria for tissue engineering. Osteochondral engineering has used scaffold-based methods that, for example, use polymers in conjunction with ceramics. Excitingly, scaffold-free methods are emerging for engineering the articular cartilage layer, which can be interfaced with an underlying bone substrate. Critical must be the objective of designing an interface that displays mechanics robust enough to withstand the native environment.

The need for organ transplants exceeds donor organ availability. In the quest to solve this shortage, the most remarkable area of advancement is organ production through the use of chimeric embryos, commonly known as blastocyst complementation. This technique involves the combination of different species to generate chimeras, where the extent of donor cell contribution to the desired tissue or organ can be regulated. However, ethical concerns arise with the use of brain tissue in such chimeras. Furthermore, the ratio of contributed cells to host animal cells in the chimeric system is low in the production of chimeras associated with cell apoptosis. This review discusses the latest innovations in blastocyst complementation and highlights the progress made in creating organs for transplant.

Age related macular degeneration and other retinal degenerative disorders are characterized by disruption of the outer blood retinal barrier (oBRB) with subsequent ischemia, neovascularization, and atrophy. Despite the treatment advances, there remains no curative therapy, and no treatment targeted at regenerating native-like tissue for patients with late stages of the disease. Here we present advances in tissue engineering, focusing on bioprinting methods of generating tissue allowing for safe and reliable production of oBRB as well as tissue reprogramming with induced pluripotent stem cells for transplantation. We compare these approaches to organ-on-a-chip models for studying the dynamic nature of physiologic conditions. Highlighted within this review are studies that employ good manufacturing practices and use clinical grade methods that minimize potential risk to patients. Lastly, we illustrate recent clinical applications demonstrating both safety and efficacy for direct patient use. These advances provide an avenue for drug discovery and ultimately transplantation.

Regenerative rehabilitation is a promising field aimed at harnessing the regenerative potential of stem-cell therapeutics to maximize functional recovery. Here, we outline recent advancements in the field of regenerative rehabilitation for treating knee osteoarthritis (KOA) and we highlight sex-specific considerations to promote knowledge translation to the clinic. A systematic review suggests that sexual dimorphism in the efficacy of regenerative rehabilitation approaches for the treatment of KOA may be partly attributed to the functional decline of female mesenchymal stem cells (MSCs) over the lifespan, particularly after menopause. These declines are likely to be accompanied by poor clinical outcomes. While evidence is far from adequate, physical therapeutics have emerged as a means to promote estrogen signaling in MSCs, potentially reversing menopause-related MSC dysfunction. This study calls for actions to dissect the effects of menopause, together with physical therapeutics, on stem-cell therapeutics toward the development of effective regenerative rehabilitation approaches.

The myotendinous junction (MTJ) acts as a bridge between muscle and tendon; yet its high stiffness relative to muscle fibers renders the tissue susceptible to injuries due to eccentric loading disparities. The limited regenerative capacity of MTJ tissue and potential for postsurgical scarring and reinjury necessitates complementary therapeutics that can enhance cellular interactions, restore mechanical properties, and support tissue rehabilitation.

This review explores various approaches to engineer the MTJ utilizing biomaterial scaffolds and cellularized materials that mimic structure and function. While biomimetic materials show promise, challenges remain due to the interface's complexity and differing patient- and location-specific structure–function characteristics, necessitating further research to address these gaps. This review also highlights the importance of studying MTJ injuries in women's health and craniofacial reconstruction. Furthermore, engineered MTJ models provide versatile platforms for investigating trauma and degeneration, thus offering potential for advancing research across multiple fields, shedding light on interactions at tissue interfaces, and shaping the future of MTJ rehabilitation.