Advanced biomedical applications based on emerging 3D cell culturing platforms.

It is of great value to develop reliable in vitro models for cell biology and toxicology. However, ethical issues and the decreasing number of donors restrict the further use of traditional animal models in various fields, including the emerging fields of tissue engineering and regenerative medicine. The huge gap created by the restrictions in animal models has pushed the development of the increasingly recognized three-dimensional (3D) cell culture, which enables cells to closely simulate authentic cellular behaviour such as close cell-to-cell interactions and can achieve higher functionality. Furthermore, 3D cell culturing is superior to the traditional 2D cell culture, which has obvious limitations and cannot closely mimic the structure and architecture of tissues. In this study, we review several methods used to form 3D multicellular spheroids. The extracellular microenvironment of 3D spheroids plays a role in many aspects of biological sciences, including cell signalling, cell growth, cancer cell generation, and anti-cancer drugs. More recently, they have been explored as basic construction units for tissue and organ engineering. We review this field with a focus on the previous research in different areas using spheroid models, emphasizing aqueous two-phase system (ATPS)-based techniques. Multi-cellular spheroids have great potential in the study of biological systems and can closely mimic the in vivo environment. New technologies to form and analyse spheroids such as the aqueous two-phase system and magnetic levitation are rapidly overcoming the technical limitations of spheroids and expanding their applications in tissue engineering and regenerative medicine.

"On Vivo" and Wearable Clinical Laboratory Testing Devices for Emergency and Critical Care Laboratory Testing.

BACKGROUND: Point-of-care testing (POCT) devices are designed for clinical laboratory testing at the bedside or near the patient and can significantly reduce the turnaround time for laboratory test results. The next generation for clinical laboratory testing may be devices that are worn or attached to the patient. CONTENT: POCT devices that are designed where samples are tested directly on the patient include bilirubinometers, pulse oximeters, breathalyzers (for alcohol and, more recently, cannabinoid detection), transcutaneous blood gas analyses, and novel testing applications such as glucose and tumor signatures following surgical excision. The utility of these devices with special reference for use within the intensive care unit and the emergency department is reviewed. SUMMARY: It is likely that wearable POCT devices will be developed in the future that can meet current and emerging clinical needs. Advancements in biomedical engineering and information technology will be needed in the creation of next-generation devices.

Frontiers of Medical Robotics: From Concept to Systems to Clinical Translation.

Medical robotics is poised to transform all aspects of medicine-from surgical intervention to targeted therapy, rehabilitation, and hospital automation. A key area is the development of robots for minimally invasive interventions. This review provides a detailed analysis of the evolution of interventional robots and discusses how the integration of imaging, sensing, and robotics can influence the patient care pathway toward precision intervention and patient-specific treatment. It outlines how closer coupling of perception, decision, and action can lead to enhanced dexterity, greater precision, and reduced invasiveness. It provides a critical analysis of some of the key interventional robot platforms developed over the years and their relative merit and intrinsic limitations. The review also presents a future outlook for robotic interventions and emerging trends in making them easier to use, lightweight, ergonomic, and intelligent, and thus smarter, safer, and more accessible for clinical use.

Chitosan in Biomedical Engineering: A Critical Review.

Biomedical engineering seeks to enhance the quality of life by developing advanced materials and technologies. Chitosan-based biomaterials have attracted significant attention because of having unique chemical structures with desired biocompatibility and biodegradability, which play different roles in membranes, sponges and scaffolds, along with promising biological properties such as biocompatibility, biodegradability and non-toxicity. Therefore, chitosan derivatives have been widely used in a vast variety of uses, chiefly pharmaceuticals and biomedical engineering. It is attempted here to draw a comprehensive overview of chitosan emerging applications in medicine, tissue engineering, drug delivery, gene therapy, cancer therapy, ophthalmology, dentistry, bio-imaging, bio-sensing and diagnosis. The use of Stem Cells (SCs) has given an interesting feature to the use of chitosan so that regenerative medicine and therapeutic methods have benefited from chitosan-based platforms. Plenty of the most recent discussions with stimulating ideas in this field are covered that could hopefully serve as hints for more developed works in biomedical engineering.

Metallic Endobronchial Stents: A Contemporary Resurrection.

Airway stenting has been practiced for several decades. It is one of the most common procedures performed by interventional pulmonologists. Typically, these stents are implanted to maintain the tubular patency of the tracheobronchial tree. They are only considered as a temporizing measure, or when a surgical option cannot be pursued. Through the past few decades, a number of metallic airway stents have been introduced into the market. First generation stents were comparatively simplistic and crafted from stainless steel. The latest generation of metallic airway stents are hybrid in nature and constructed with complex alloys. As airway stenting become more widely practiced, concerns arose regarding their safety. However, with improved understanding of stent-airway interactions, advancements in biomedical engineering, and a larger emphasis on post procedural care, the use of metallic endobronchial stents has been resurrected. We present the history, technological advancement, and contemporary indications of metallic airway stents.

New Horizons in Advocacy Engaged Physical Sciences and Oncology Research.

To address cancer as a multifaceted adaptive system, the increasing momentum for cross-disciplinary connectivity between cancer biologists, physical scientists, mathematicians, chemists, biomedical engineers, computer scientists, clinicians, and advocates is fueling the emergence of new scientific frontiers, principles, and opportunities within physical sciences and oncology. In parallel to highlighting the advances, challenges, and acceptance of advocates as credible contributors, we offer recommendations for addressing real world hurdles in advancing equitable partnerships among advocacy stakeholders.

Reengineering the Tumor Vasculature: Improving Drug Delivery and Efficacy.

A solid tumor is like an aberrant organ - comprised of cancer cells and a variety of host cells embedded in an extracellular matrix - nourished by blood vessels and drained by lymphatic vessels. In its journey from the blood stream to cancer cells, a therapeutic agent must cross the vessel wall and the extracellular matrix that cancer cells are ensconced in. Growth of tumors in a confined space along with deposition of matrix components, including collagen (yellow) and hyaluronan (pink), increases 'solid stress', which compresses blood and lymphatic vessels and impairs their function. The leakiness of tumor vessels also impairs tumor blood flow and increases 'intratumor fluid pressure'. The abnormal blood flow not only impedes drug delivery, but the resulting hypoxia also aids tumor invasion, metastasis, immunosuppression, inflammation, fibrosis, and treatment resistance. Engineers and physical scientists have dissected the molecular, cellular, and physical mechanisms underlying these abnormalities and developed a number of strategies to reengineer the tumor microenvironment to overcome these barriers and thus improve delivery and efficacy of treatments. Finally, these strategies have been translated from bench to bedside for treatment of cancer and have the potential to improve the treatment outcome for many diseases characterized by an abnormal microenvironment.

Practical whole-tooth restoration utilizing autologous bioengineered tooth germ transplantation in a postnatal canine model.

Whole-organ regeneration has great potential for the replacement of dysfunctional organs through the reconstruction of a fully functional bioengineered organ using three-dimensional cell manipulation in vitro. Recently, many basic studies of whole-tooth replacement using three-dimensional cell manipulation have been conducted in a mouse model. Further evidence of the practical application to human medicine is required to demonstrate tooth restoration by reconstructing bioengineered tooth germ using a postnatal large-animal model. Herein, we demonstrate functional tooth restoration through the autologous transplantation of bioengineered tooth germ in a postnatal canine model. The bioengineered tooth, which was reconstructed using permanent tooth germ cells, erupted into the jawbone after autologous transplantation and achieved physiological function equivalent to that of a natural tooth. This study represents a substantial advancement in whole-organ replacement therapy through the transplantation of bioengineered organ germ as a practical model for future clinical regenerative medicine.

Synthesis methods to prepare single- and multi-core iron oxide nanoparticles for biomedical applications.

We review current synthetic routes to magnetic iron oxide nanoparticles for biomedical applications. We classify the different approaches used depending on their ability to generate magnetic particles that are either single-core (containing only one magnetic core, i.e. a single domain nanocrystal) or multi-core (containing several magnetic cores, i.e. single domain nanocrystals). The synthesis of single-core magnetic nanoparticles requires the use of surfactants during the particle generation, and careful control of the particle coating to prevent aggregation. Special attention has to be paid to avoid the presence of any toxic reagents after the synthesis if biomedical applications are intended. Several approaches exist to obtain multi-core particles based on the coating of particle aggregates; nevertheless, the production of multi-core particles with good control of the number of magnetic cores per particle, and of the degree of polydispersity of the core sizes, is still a difficult task. The control of the structure of the particles is of great relevance for biomedical applications as it has a major influence on the magnetic properties of the materials.

Interview: Nanomedicine: past, present and future.

Professor Thomas Webster received his Bachelor of Science degree in chemical engineering from the University of Pittsburgh (PA, USA) in 1995. He subsequently received his Masters degree in biomedical engineering in 1997 from Rensselaer Polytechnic Institute (NY, USA). He completed his PhD at the same institution in 2000. Currently, Professor Webster is the Department Chair and Professor of Chemical Engineering at Northeastern University (MA, USA). He previously held the position of Associate Professor for the Division of Engineering at Brown University (RI, USA) and the Division of Orthopedic Surgery at Brown University Medical School. He is an elected Fellow of the American Institute for Medical and Biological Engineering, which represents the top 2% of all medical and biological engineers. Professor Webster's research has led to the formation of nine start-up companies. He has authored over 400 peer-reviewed publications and issued more than 30 patents.