Regenerative medicine technologies applied to transplant medicine. An update

3D bioprinting for bile duct tissue engineering: current status and prospects

Bile duct disorders, including cholangiocarcinoma, primary sclerosing cholangitis, and iatrogenic injuries, pose significant clinical challenges due to limited regenerative capacity and the complexity of the biliary tree. In recent years, 3D bioprinting has emerged as a promising approach for bile duct tissue engineering by providing patient-specific geometries and facilitating the spatial organization of cells, scaffolding materials, and bioactive factors. This review presents a comprehensive overview of 3D bioprinting techniques for bile duct tissue engineering, focusing on fundamental principles, biomaterial selection, current achievements, key challenges, and future perspectives. We systematically discuss the latest technological breakthroughs, highlight emerging innovations such as organoid-based strategies and microfluidic-assisted 3D printing, and evaluate the prospects for clinical translation. Finally, we outline the main challenges-such as biocompatibility of materials, vascularization, immunological barriers, standardization of protocols, and regulatory hurdles-and propose directions for future research, emphasizing multidisciplinary collaboration and translational studies.

Three-dimensional bio-derived materials for biomedical applications: challenges and opportunities

Three-dimensional (3D) bio-derived materials are emerging as a promising approach to enhance wound healing therapies. These innovative materials can be tailored to meet the specific needs of various wound types and patients, facilitating the controlled release of therapeutic agents such as growth factors and antibiotics, which promote cell growth and tissue regeneration. Despite their potential, significant challenges remain in achieving optimal biocompatibility, ensuring structural integrity, and maintaining precise release mechanisms. Additionally, issues such as scalability, cost-effectiveness, and regulatory compliance pose substantial barriers to widespread use. However, recent advances in materials science and interdisciplinary research offer new opportunities to overcome these challenges. This review provides a comprehensive analysis of the current state of 3D bio-derived materials in biomedical applications, highlighting the types of materials available, their advantages and limitations, and the progress made in their design and development. It also outlines new directions for future research aimed at bridging the gap between scientific discoveries and their practical applications in injury healing strategies. The findings of this review underscore the significant potential of 3D bio-derived materials in revolutionizing wound healing and advancing personalized therapeutic approaches.

High-throughput platform for label-free sorting of 3D spheroids using deep learning

End-stage liver diseases have an increasing impact worldwide, exacerbated by the shortage of transplantable organs. Recognized as one of the promising solutions, tissue engineering aims at recreating functional tissues and organs in vitro. The integration of bioprinting technologies with biological 3D models, such as multi-cellular spheroids, has enabled the fabrication of tissue constructs that better mimic complex structures and in vivo functionality of organs. However, the lack of methods for large-scale production of homogeneous spheroids has hindered the upscaling of tissue fabrication. In this work, we introduce a fully automated platform, designed for high-throughput sorting of 3D spheroids based on label-free analysis of brightfield images. The compact platform is compatible with standard biosafety cabinets and includes a custom-made microscope and two fluidic systems that optimize single spheroid handling to enhance sorting speed. We use machine learning to classify spheroids based on their bioprinting compatibility. This approach enables complex morphological analysis, including assessing spheroid viability, without relying on invasive fluorescent labels. Furthermore, we demonstrate the efficacy of transfer learning for biological applications, for which acquiring large datasets remains challenging. Utilizing this platform, we efficiently sort mono-cellular and multi-cellular liver spheroids, the latter being used in bioprinting applications, and confirm that the sorting process preserves viability and functionality of the spheroids. By ensuring spheroid homogeneity, our sorting platform paves the way for standardized and scalable tissue fabrication, advancing regenerative medicine applications.

Tissue chips as headway model and incitement technology

Tissue on a chip or organ-on-chip (OOC) is a technology that's dignified to form a transformation in drug discovery through the use of advanced platforms. These are 3D in-vitro cell culture models that mimic micro-environment of human organs or tissues on artificial microstructures built on a portable microfluidic chip without involving sacrificial humans or animals. This review article aims to offer readers a thorough and insightful understanding of technology. It begins with an in-depth understanding of chip design and instrumentation, underlining its pivotal role and the imperative need for its development in the modern scientific landscape. The review article explores into the myriad applications of OOC technology, showcasing its transformative impact on fields such as radiobiology, drug discovery and screening, and its pioneering use in space research. In addition to highlighting these diverse applications, the article provides a critical analysis of the current challenges that OOC technology faces. It examines both the biological and technical limitations that hinder its progress and efficacy and discusses the potential advancements and innovations that could drive the OOC technology forward. Through this comprehensive review, readers will gain a deep appreciation of the significance, capabilities, and evolving landscape of OOC technology.

Bibliometric analysis of organoids in regenerative medicine-related research worldwide over two decades (2002-2022)

Aim: This study aimed to evaluate the trends in organoid culture research within the field of regenerative medicine from 2002 to 2022. Methods: The worldwide distribution of organoid research in regenerative medicine articles indexed in the Scopus database was analyzed. Result: A total of 840 documents were analyzed, averaging 42 publications annually. The USA (n = 296) led in publications, followed by China (n = 127), Japan (n = 91) and the UK (n = 75). Since 2011, research has surged, particularly in China, which emerged as a prominent center. Conclusion: The findings highlight significant growth in organoid research, promising future organ transplantation. Research trends integrate tissue engineering, gene modification and induced pluripotent stem cell technologies, reflecting a move toward personalized medicine.

Development of Matrix Metalloproteinases-Mediated Extracellular Matrix Remodeling in Regenerative Medicine: A Mini Review

Extracellular matrix (ECM) components confer biomechanical properties, maintain cell phenotype and mediate tissue homeostasis. ECM remodeling is complex and plays a key role in both physiological and pathological processes. Matrix metalloproteinases (MMPs) are a group of enzymes responsible for ECM degradation and have been accepted as a key regulator in ECM remodeling. In this mini-review, we summarize MMPs categories, functions and the targeted substrates. We then discuss current understanding of the role of MMPs-mediated events, including inflammation reaction, angiogenesis, cellular activities, etc., in ECM remodeling in the context of regenerative medicine.

Mitochondria Have Made a Long Evolutionary Path from Ancient Bacteria Immigrants within Eukaryotic Cells to Essential Cellular Hosts and Key Players in Human Health and Disease

Mitochondria have made a long evolutionary path from ancient bacteria immigrants within the eukaryotic cell to become key players for the cell, assuming crucial multitasking skills critical for human health and disease. Traditionally identified as the powerhouses of eukaryotic cells due to their central role in energy metabolism, these chemiosmotic machines that synthesize ATP are known as the only maternally inherited organelles with their own genome, where mutations can cause diseases, opening up the field of mitochondrial medicine. More recently, the omics era has highlighted mitochondria as biosynthetic and signaling organelles influencing the behaviors of cells and organisms, making mitochondria the most studied organelles in the biomedical sciences. In this review, we will especially focus on certain 'novelties' in mitochondrial biology "left in the shadows" because, although they have been discovered for some time, they are still not taken with due consideration. We will focus on certain particularities of these organelles, for example, those relating to their metabolism and energy efficiency. In particular, some of their functions that reflect the type of cell in which they reside will be critically discussed, for example, the role of some carriers that are strictly functional to the typical metabolism of the cell or to the tissue specialization. Furthermore, some diseases in whose pathogenesis, surprisingly, mitochondria are involved will be mentioned.

Magnetic Nanomaterials Mediate Electromagnetic Stimulations of Nerves for Applications in Stem Cell and Cancer Treatments

Although some progress has been made in the treatment of cancer, challenges remain. In recent years, advancements in nanotechnology and stem cell therapy have provided new approaches for use in regenerative medicine and cancer treatment. Among them, magnetic nanomaterials have attracted widespread attention in the field of regenerative medicine and cancer; this is because they have high levels of safety and low levels of invasibility, promote stem cell differentiation, and affect biological nerve signals. In contrast to pure magnetic stimulation, magnetic nanomaterials can act as amplifiers of an applied electromagnetic field in vivo, and by generating different effects (thermal, electrical, magnetic, mechanical, etc.), the corresponding ion channels are activated, thus enabling the modulation of neuronal activity with higher levels of precision and local modulation. In this review, first, we focused on the relationship between biological nerve signals and stem cell differentiation, and tumor development. In addition, the effects of magnetic nanomaterials on biological neural signals and the tumor environment were discussed. Finally, we introduced the application of magnetic-nanomaterial-mediated electromagnetic stimulation in regenerative medicine and its potential in the field of cancer therapy.