Human body constitutes unique biological system containing specific fluid mechanics and biomechanics. Traditional cell culture techniques of 2D and 3D do not recapitulate these specific natures of the human system. In addition, they lack the spatiotemporal conditions of representing the cells. Moreover, they do not enable the study of cell-cell interactions in multiple cell culture platforms. Therefore, establishing biological system of dynamic cell culture was of great interest. Organs on chips systems were fabricated proving their concept to mimic specific organs functions. Therefore, it paves the way for validating new drugs and establishes mechanisms of emerging diseases. It has played a key role in validating suitable vaccines for Coronavirus disease (COVID-19). Herein, the concept of organs on chips, fabrication methodology and their applications are discussed.

OBJECTIVE: While there are a wide range of approaches for the assessment of skin hydration, it is not always clear how data from them relate to one another or to the skin itself. With the development of in vivo Confocal Raman Spectroscopy (ICRS), it has become possible to measure water concentration as a function of protein/depth within the stratum corneum (SC). This article reports a comparison between electrical skin hydration measures/visual/optical grading and water concentration profiles measured using ICRS, to better understand the relationship between these approaches.
METHODS: SC hydration of lower-leg skin with varying degrees of dryness was assessed using visual grading (live and from digital images), Corneometer®, Visioscan and ICRS. In addition, a custom fingerprint sensor was used to image surface capacitance (as a surrogate of SC hydration), and SC barrier function was assessed using evaporimetry (to measure trans-epidermal water loss; TEWL).
RESULTS: Significant correlations were observed between a number of different skin grading/measurement approaches and ICRS data. ICRS hydration profiles also revealed a region near the SC surface with a relatively flat water profile in dry skin subjects.
CONCLUSIONS: The advent of quantitative in vivo analytical techniques such as ICRS, which can be used in a clinical setting, has enabled greater insight into more conventional approaches for assessing skin dryness. While traditional skin grading and biophysical methods for measuring skin hydration have varying degrees of correlation with one another, they also provide comparatively unique information about different regions within the SC. This should enable a more informed approach to product development in the future.
OBJECTIVE: Bien qu’il existe un large éventail d’approches pour évaluer l’hydratation de la peau, la façon dont les données qui en résultent sont liées les unes aux autres ou à la peau elle‐même n’est pas toujours claire. Avec le développement de la spectroscopie Raman confocale in vivo (ICRS), il est devenu possible de mesurer la concentration en eau en fonction du rapport protéine/profondeur au sein de la couche cornée (stratum corneum, SC). Cet article rapporte une comparaison entre les mesures électriques ou la classification visuelle/optique de l’hydratation de la peau et les profils de concentration en eau mesurés à l’aide de l’ICRS, afin de mieux comprendre la relation entre ces approches. MÉTHODES: L’hydratation du SC de la peau de la partie inférieure de la jambe avec différents degrés de sécheresse a été évaluée à l’aide d’une classification visuelle (en direct et à partir d’images numériques), du Corneometer®, du Visioscan et de l’ICRS. En outre, un capteur d’empreintes digitales personnalisé a été utilisé pour visualiser la capacité de surface (en tant que substitut de l’hydratation du SC) et la fonction de barrière du SC a été évaluée par évaporimétrie (pour mesurer la perte d’eau transépidermique ; trans‐epidermal water loss, TEWL). RÉSULTATS: Des corrélations significatives ont été observées entre un certain nombre d’approches différentes de classification/mesure de la peau et les données ICRS. Les profils d’hydratation de l’ICRS ont également révélé une région près de la surface du SC ayant un profil d’eau relativement plat chez les sujets atteints de sécheresse cutanée.
CONCLUSIONS: L’avènement de techniques d’analyse in vivo quantitatives telles que l’ICRS, qui peut être utilisée dans un contexte clinique, a permis de mieux comprendre les approches plus conventionnelles d’évaluation de la sécheresse cutanée. Bien que les méthodes traditionnelles de classification de la peau et les méthodes biophysiques de mesure de l’hydratation de la peau présentent des degrés de corrélation variables entre elles, elles fournissent également des informations comparativement uniques sur différentes régions au sein du SC. Cela devrait permettre une approche plus éclairée du développement de produits à l’avenir.

The possibility of abrupt transitions threatens to poise ecosystems into irreversibly degraded states. Synthetic biology has recently been proposed to prevent them from crossing tipping points. However, there is little understanding of the impact of such intervention on the resident communities. Can such modification have \'unintended consequences\', such as loss of species? Here, we address this problem by using a mathematical model that allows us to simulate this intervention scenario explicitly. We show how the indirect effect of damping the decay of shared resources results in biodiversity increase, and last but not least, the successful incorporation of the synthetic within the ecological network and very small-positive changes in the population size of the resident community. Furthermore, extensions and implications for future restoration and terraformation strategies are discussed.

BACKGROUND: Assisted Reproductive Technologies (ARTs) have been validated in human and animal to solve reproductive problems such as infertility, aging, genetic selection/amplification and diseases. The persistent gap in ART biomedical applications lies in recapitulating the early stage of ovarian folliculogenesis, thus providing protocols to drive the large reserve of immature follicles towards the gonadotropin-dependent phase. Tissue engineering is becoming a concrete solution to potentially recapitulate ovarian structure, mostly relying on the use of autologous early follicles on natural or synthetic scaffolds. Based on these premises, the present study has been designed to validate the use of the ovarian bioinspired patterned electrospun fibrous scaffolds fabricated with poly(ε-caprolactone) (PCL) for multiple preantral (PA) follicle development.
METHODS: PA follicles isolated from lamb ovaries were cultured on PCL scaffold adopting a validated single-follicle protocol (Ctrl) or simulating a multiple-follicle condition by reproducing an artificial ovary engrafted with 5 or 10 PA (AO5PA and AO10PA). The incubations were protracted for 14 and 18 days before assessing scaffold-based microenvironment suitability to assist in vitro folliculogenesis (ivF) and oogenesis at morphological and functional level.
RESULTS: The ivF outcomes demonstrated that PCL-scaffolds generate an appropriate biomimetic ovarian microenvironment supporting the transition of multiple PA follicles towards early antral (EA) stage by supporting follicle growth and steroidogenic activation. PCL-multiple bioengineering ivF (AO10PA) performed in long term generated, in addition, the greatest percentage of highly specialized gametes by enhancing meiotic competence, large chromatin remodeling and parthenogenetic developmental competence.
CONCLUSIONS: The study showcased the proof of concept for a next-generation ART use of PCL-patterned scaffold aimed to generate transplantable artificial ovary engrafted with autologous early-stage follicles or to advance ivF technologies holding a 3D bioinspired matrix promoting a physiological long-term multiple PA follicle protocol.

Louis Prahl is a postdoctoral fellow in Alex Hughes\' lab in the Department of Bioengineering and the Center for Soft and Living Matter at the University of Pennsylvania, Philadelphia, USA. He is interested in how epithelial cells organise into complex structures and in developing engineering strategies to control tissue organisation. Louis is one of the 2024 fellows of the Pathway to Independence Programme. We caught up with him to talk about his physics and bioengineering background, his interdisciplinary research interests, and his plans as an independent researcher.

Intestinal failure manifests as an impaired capacity of the intestine to sufficiently absorb vital nutrients and electrolytes essential for growth and well-being in pediatric and adult populations. Although parenteral nutrition remains the mainstay therapeutic approach, the pursuit of a definitive and curative strategy, such as regenerative medicine, is imperative. Substantial advancements in the field of engineered intestinal tissues present a promising avenue for addressing intestinal failure; nevertheless, extensive research is still necessary for effective translation from experimental benchwork to clinical bedside applications.

Our study explores the development of collagen membranes with integrated minocycline or irinotecan, targeting applications in tissue engineering and drug delivery systems. Type I collagen, extracted from bovine skin using advanced fibril-forming technology, was crosslinked with glutaraldehyde to create membranes. These membranes incorporated minocycline, an antibiotic, or irinotecan, a chemotherapeutic agent, in various concentrations. The membranes, varying in drug concentration, were studied by water absorption and enzymatic degradation tests, demonstrating a degree of permeability. We emphasize the advantages of local drug delivery for treating high-grade gliomas, highlighting the targeted approach\'s efficacy in reducing systemic adverse effects and enhancing drug bioavailability at the tumor site. The utilization of collagen membranes is proposed as a viable method for local drug delivery. Irinotecan\'s mechanism, a topoisomerase I inhibitor, and minocycline\'s broad antibacterial spectrum and inhibition of glial cell-induced membrane degradation are discussed. We critically examine the challenges posed by the systemic administration of chemotherapeutic agents, mainly due to the blood-brain barrier\'s restrictive nature, advocating for local delivery methods as a more effective alternative for glioblastoma treatment. These local delivery strategies, including collagen membranes, are posited as significant advancements in enhancing therapeutic outcomes for glioblastoma patients.

Biomaterials, whether of biological or synthetic origin, have risen to the forefront of modern medical innovation since the early 2000s, transcending their traditional roles in orthopedic and dental applications, to encompass drug delivery systems, implantable biosensors, and templates for cellular growth and tissue regeneration [...].

The vast regenerative potential of stem cells has laid the foundation for stem cell-based therapies. However, certain challenges limit the application of cell-based therapies. The therapeutic use of cell-free therapy can avoid limitations associated with cell-based therapies. Acellular stem cell-based therapies rely on the use of biological factors released by stem cells, including growth factors and extracellular vesicles such as exosomes. Due to their comparable regenerative potential, acellular therapies may provide a feasible and scalable alternative to stem cell-based therapies. Exosomes are small vesicles secreted by various types of cells, including stem cells. Exosomes contain parent cell-derived nucleic acids, proteins, lipids, and other bioactive molecules. They play an important role in intra-cellular communication and influence the biological characteristics of cells. Exosomes inherit the properties of their parent cells; therefore, stem cell-derived exosomes are of particular interest for applications of regenerative medicine. In comparison to stem cell-based therapy, exosome therapy offers several benefits, such as easy transport and storage, no risk of immunological rejection, and few ethical dilemmas. Unlike stem cells, exosomes can be lyophilized and stored off-the-shelf, making acellular therapies standardized and more accessible while reducing overall treatment costs. Exosome-based acellular treatments are therefore readily available for applications in patients at the time of care. The current review discusses the use of exosomes as an acellular therapy. The review explores the molecular mechanism of exosome biogenesis, various methods for exosome isolation, and characterization. In addition, the latest advancements in bioengineering techniques to enhance exosome potential for acellular therapies have been discussed. The challenges in the use of exosomes as well as their diverse applications for the diagnosis and treatment of diseases have been reviewed in detail.

Mesenchymal stem/stromal cells (MSCs) are one of the most widely used cell types in advanced therapies due to their therapeutic potential in the regulation of tissue repair and homeostasis, and immune modulation. However, their use in cancer therapy is controversial: they can inhibit cancer cell proliferation, but also potentially promote tumour growth by supporting angiogenesis, modulation of the immune milieu and increasing cancer stem cell invasiveness. This opposite behaviour highlights the need for careful and nuanced use of MSCs in cancer treatment. To optimize their anti-cancer effects, diverse strategies have bioengineered MSCs to enhance their tumour targeting and therapeutic properties or to deliver anti-cancer drugs. In this review, we highlight the advanced uses of MSCs in cancer therapy, particularly as carriers of targeted treatments due to their natural tumour-homing capabilities. We also discuss the potential of MSC-derived extracellular vesicles to improve the efficiency of drug or molecule delivery to cancer cells. Ongoing clinical trials are evaluating the therapeutic potential of these cells and setting the stage for future advances in MSC-based cancer treatment. It is critical to identify the broad and potent applications of bioengineered MSCs in solid tumour targeting and anti-cancer agent delivery to position them as effective therapeutics in the evolving field of cancer therapy.