Developing organ-on-a-chip concepts using bio-mechatronic design methodology

A microfluidic organ-on-a-chip: into the next decade of bone tissue engineering applied in dentistry

A comprehensive understanding of the complex physiological and pathological processes associated with alveolar bones, their responses to different therapeutics strategies, and cell interactions with biomaterial becomes necessary in precisely treating patients with severe progressive periodontitis, as a bone-related issue in dentistry. However, existing monolayer cell culture or pre-clinical models have been unable to mimic the complex physiological, pathological and regeneration processes in the bone microenvironment in response to different therapeutic strategies. In this point, 'organ-on-a-chip' (OOAC) technology, specifically 'alveolar-bone-on-a-chip', is expected to resolve the problems by better imitating infection site microenvironment and microphysiology within the oral tissues. The OOAC technology is assessed in this study toward better approaches in disease modeling and better therapeutics strategy for bone tissue engineering applied in dentistry.

Polymeric Based Hydrogel Membranes for Biomedical Applications

The development of biomedical applications is a transdisciplinary field that in recent years has involved researchers from chemistry, pharmacy, medicine, biology, biophysics, and biomechanical engineering. The fabrication of biomedical devices requires the use of biocompatible materials that do not damage living tissues and have some biomechanical characteristics. The use of polymeric membranes, as materials meeting the above-mentioned requirements, has become increasingly popular in recent years, with outstanding results in tissue engineering, for regeneration and replenishment of tissues constituting internal organs, in wound healing dressings, and in the realization of systems for diagnosis and therapy, through the controlled release of active substances. The biomedical application of hydrogel membranes has had little uptake in the past due to the toxicity of cross-linking agents and to the existing limitations regarding gelation under physiological conditions, but now it is proving to be a very promising field This review presents the important technological innovations that the use of membrane hydrogels has promoted, enabling the resolution of recurrent clinical problems, such as post-transplant rejection crises, haemorrhagic crises due to the adhesion of proteins, bacteria, and platelets on biomedical devices in contact with blood, and poor compliance of patients undergoing long-term drug therapies.

Advances in Organ-on-a-Chip Materials and Devices

The organ-on-a-chip (OoC) paves a way for biomedical applications ranging from preclinical to clinical translational precision. The current trends in the in vitro modeling is to reduce the complexity of human organ anatomy to the fundamental cellular microanatomy as an alternative of recreating the entire cell milieu that allows systematic analysis of medicinal absorption of compounds, metabolism, and mechanistic investigation. The OoC devices accurately represent human physiology in vitro; however, it is vital to choose the correct chip materials. The potential chip materials include inorganic, elastomeric, thermoplastic, natural, and hybrid materials. Despite the fact that polydimethylsiloxane is the most commonly utilized polymer for OoC and microphysiological systems, substitute materials have been continuously developed for its advanced applications. The evaluation of human physiological status can help to demonstrate using noninvasive OoC materials in real-time procedures. Therefore, this Review examines the materials used for fabricating OoC devices, the application-oriented pros and cons, possessions for device fabrication and biocompatibility, as well as their potential for downstream biochemical surface alteration and commercialization. The convergence of emerging approaches, such as advanced materials, artificial intelligence, machine learning, three-dimensional (3D) bioprinting, and genomics, have the potential to perform OoC technology at next generation. Thus, OoC technologies provide easy and precise methodologies in cost-effective clinical monitoring and treatment using standardized protocols, at even personalized levels. Because of the inherent utilization of the integrated materials, employing the OoC with biomedical approaches will be a promising methodology in the healthcare industry.

Realization of user‐friendly bioanalytical tools to quantify and monitor critical components in bio‐industrial processes through conceptual design

This minireview suggests a conceptual and user‐oriented approach for the design of process monitoring systems in bioprocessing. Advancement of process analytical techniques for quantification of critical analytes can take advantage of basic conceptual process design to support reasoning, reconsidering and ranking solutions. Issues on analysis in complex bio‐industrial media, sensitivity and selectivity are highlighted from users’ perspectives. Meeting challenging analytical demands for understanding the critical interplay between the emerging bioprocesses, their biomolecular complexity and the needs for user‐friendly analytical tools are discussed. By that, a thorough design approach is suggested based on a holistic design thinking in the quest for better analytical opportunities to solve established and emerging analytical needs.

New Frontiers for Biofabrication and Bioreactor Design in Microphysiological System Development

Microphysiological systems (MPSs) have been proposed as an improved tool to recreate the complex biological features of the native niche with the goal of improving in vitro-in vivo extrapolation. In just over a decade, MPS technologies have progressed from single-tissue chips to multitissue plates with integrated pumps for perfusion. Concurrently, techniques for biofabrication of complex 3D constructs for regenerative medicine and 3D in vitro models have evolved into a diverse toolbox for micrometer-scale deposition of cells and cell-laden bioinks. However, as the complexity of biological models increases, experimental throughput is often compromised. This review discusses the existing disparity between MPS complexity and throughput, then examines an MPS-terminated biofabrication line to identify the hurdles and potential approaches to overcoming this disparity.

Intervertebral disc organ culture for the investigation of disc pathology and regeneration - benefits, limitations, and future directions of bioreactors

Low back pain is the leading cause of disability worldwide and in many patients the source of pain can be attributed to pathological changes within the intervertebral disc (IVD). As present treatment options fail to address the underlying biological problem, novel therapies are currently subject to intense research. The physiologic IVD microenvironment features a highly complex interaction of biochemical and mechanical factors influencing cell metabolism and extracellular matrix turnover and is therefore difficult to simulate for research purposes on IVD pathology. The first whole organ culture models were not able to sufficiently replicate human in vivo conditions as mechanical loading, the predominant way of IVD nutrient supply and waste exchange, remained disregarded. To mimic the unique IVD niche more realistically, whole organ culture bioreactors have been developed, allowing for dynamic loading of IVDs and nutrient exchange. Recent advancements on bioreactor systems have facilitated whole organ culture of various IVDs for extended periods. IVD organ culture bioreactors have the potential to bridge the gap between in vitro and in vivo systems and thus may give valuable insights on IVD pathology and/or potential novel treatment approaches if the respective model is adjusted according to a well-defined research question. In this review, we outline the potential of currently utilized IVD bioreactor systems and present suggestions for further developments to more reliably investigate IVD biology and novel treatment approaches.

Integrating Organs-on-Chips: Multiplexing, Scaling, Vascularization, and Innervation

Organs-on-chips (OoCs) have attracted significant attention because they can be designed to mimic in vivo environments. Beyond constructing a single OoC, recent efforts have tried to integrate multiple OoCs to broaden potential applications such as disease modeling and drug discoveries. However, various challenges remain for integrating OoCs towards in vivo-like operation, such as incorporating various connections for integrating multiple OoCs. We review multiplexed OoCs and challenges they face: scaling, vascularization, and innervation. In our opinion, future OoCs will be constructed to have increased predictive power for in vivo phenomena and will ultimately become a mainstream tool for high quality biomedical and pharmaceutical research.

Stem cell-based Lung-on-Chips: The best of both worlds?

Pathologies of the respiratory system such as lung infections, chronic inflammatory lung diseases, and lung cancer are among the leading causes of morbidity and mortality, killing one in six people worldwide. Development of more effective treatments is hindered by the lack of preclinical models of the human lung that can capture the disease complexity, highly heterogeneous disease phenotypes, and pharmacokinetics and pharmacodynamics observed in patients. The merger of two novel technologies, Organs-on-Chips and human stem cell engineering, has the potential to deliver such urgently needed models. Organs-on-Chips, which are microengineered bioinspired tissue systems, recapitulate the mechanochemical environment and physiological functions of human organs while concurrent advances in generating and differentiating human stem cells promise a renewable supply of patient-specific cells for personalized and precision medicine. Here, we discuss the challenges of modeling human lung pathophysiology in vitro, evaluate past and current models including Organs-on-Chips, review the current status of lung tissue modeling using human pluripotent stem cells, explore in depth how stem-cell based Lung-on-Chips may advance disease modeling and drug testing, and summarize practical consideration for the design of Lung-on-Chips for academic and industry applications.

Evaluating the Effect of Drug Compounds on Cardiac Spheroids Using the Cardiac Cell Outgrowth Assay

The ideal cell culture model should mimic the cell physiology and the mechanical and the chemical cues that are present in specific tissues and organs, within a convenient high-throughput format. A possible key feature for such models is to recapture the cell polarity, the interactions between cells, and the interactions between the cells and the elastic extracellular matrix (ECM) by orienting the cells in a three-dimensional (3D) matrix. A common method to create 3D cell environments is to let the cells aggregate into spheroids with a diameter of around 200 μm. A major challenge for 3D cell cultures is to perform quick and easy imaging of the dense cell population, especially noninvasively. This protocol explains how to take advantage of the number of cells growing out from cell spheroids over time as a readout of the effect of a drug. The assay is compatible with standard imaging techniques and can be performed noninvasively using light microscopy or as a complement to other fluorescent imaging assays.

Conceptual Design of Micro-Bioreactors and Organ-on-Chips for Studies of Cell Cultures

Engineering design of microbioreactors (MBRs) and organ-on-chip (OoC) devices can take advantage of established design science theory, in which systematic evaluation of functional concepts and user requirements are analyzed. This is commonly referred to as a conceptual design. This review article compares how common conceptual design principles are applicable to MBR and OoC devices. The complexity of this design, which is exemplified by MBRs for scaled-down cell cultures in bioprocess development and drug testing in OoCs for heart and eye, is discussed and compared with previous design solutions of MBRs and OoCs, from the perspective of how similarities in understanding design from functionality and user purpose perspectives can more efficiently be exploited. The review can serve as a guideline and help the future design of MBR and OoC devices for cell culture studies.

Mechanically induced development and maturation of human intestinal organoids in vivo

The natural ability of stem cells to self-organize into functional tissue has been harnessed for the production of functional human intestinal organoids. Although dynamic mechanical forces play a central role in intestinal development and morphogenesis, conventional methods for the generation of intestinal organoids have relied solely on biological factors. Here, we show that the incorporation of uniaxial strain, by using compressed nitinol springs, in human intestinal organoids transplanted into the mesentery of mice induces growth and maturation of the organoids. Assessment of morphometric parameters, transcriptome profiling, and functional assays of the strain-exposed tissue revealed higher similarities to native human intestine, with regards to tissue size and complexity, and muscle tone. Our findings suggest that the incorporation of physiologically relevant mechanical cues during the development of human intestinal tissue enhances its maturation and enterogenesis.