Effects of age and eggshell thickness on the hatching results of stored broiler breeder eggs.

The present study was conducted to determine the effects of breeder age and eggshell thickness on the hatching results of broiler breeders. A total of 3000 eggs were collected from three flocks at different ages, viz., 27 (young), 48 (middle-aged) and 65 (old) weeks. Eggs were individually weighed and eggshell thicknesses were determined using an ultrasound gauge. The eggs of each age group were classified as thin-, medium- or thick-shelled and stored for 7 days at 18°C and 60% relative humidity prior to incubation. Total egg weight loss during storage and incubation was higher in middle-aged (48 weeks old) flock eggs (11.46%) than in young (10.14%) and old (10.37%) flock eggs. Hatchability was significantly lower in the eggs of the old flock than of the other flocks. The highest hatchability (70.6%) was observed in the young flock. Eggs with thick shells better tolerated the detrimental effects of storage and more eggs remained fertile than amongst the medium- and thin-shelled eggs. The overall hatchability of the old flock was 38.0%, whilst hatchability of set eggs in the thick-shelled group of old flock eggs was 58.3%.

CRISPR/Cas9-based targeted genome editing for correction of recessive dystrophic epidermolysis bullosa using iPS cells.

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited skin disorder caused by mutations in the COL7A1 gene encoding type VII collagen (C7). The spectrum of severity depends on the type of mutation in the COL7A1 gene. C7 is the major constituent of anchoring fibrils (AFs) at the basement membrane zone (BMZ). Patients with RDEB lack functional C7 and have severely impaired dermal-epidermal stability, resulting in extensive blistering and open wounds on the skin that greatly affect the patient's quality of life. There are currently no therapies approved for the treatment of RDEB. Here, we demonstrated the correction of mutations in exon 19 (c.2470insG) and exon 32 (c.3948insT) in the COL7A1 gene through homology-directed repair (HDR). We used the clustered regulatory interspaced short palindromic repeats (CRISPR) Cas9-gRNAs system to modify induced pluripotent stem cells (iPSCs) derived from patients with RDEB in both the heterozygous and homozygous states. Three-dimensional human skin equivalents (HSEs) were generated from gene-corrected iPSCs, differentiated into keratinocytes (KCs) and fibroblasts (FBs), and grafted onto immunodeficient mice, which showed normal expression of C7 at the BMZ as well as restored AFs 2 mo postgrafting. Safety assessment for potential off-target Cas9 cleavage activity did not reveal any unintended nuclease activity. Our findings represent a crucial advance for clinical applications of innovative autologous stem cell-based therapies for RDEB.

Microfluidic blood-brain barrier model provides in vivo-like barrier properties for drug permeability screening.

Efficient delivery of therapeutics across the neuroprotective blood-brain barrier (BBB) remains a formidable challenge for central nervous system drug development. High-fidelity in vitro models of the BBB could facilitate effective early screening of drug candidates targeting the brain. In this study, we developed a microfluidic BBB model that is capable of mimicking in vivo BBB characteristics for a prolonged period and allows for reliable in vitro drug permeability studies under recirculating perfusion. We derived brain microvascular endothelial cells (BMECs) from human induced pluripotent stem cells (hiPSCs) and cocultured them with rat primary astrocytes on the two sides of a porous membrane on a pumpless microfluidic platform for up to 10 days. The microfluidic system was designed based on the blood residence time in human brain tissues, allowing for medium recirculation at physiologically relevant perfusion rates with no pumps or external tubing, meanwhile minimizing wall shear stress to test whether shear stress is required for in vivo-like barrier properties in a microfluidic BBB model. This BBB-on-a-chip model achieved significant barrier integrity as evident by continuous tight junction formation and in vivo-like values of trans-endothelial electrical resistance (TEER). The TEER levels peaked above 4000 Ω · cm2 on day 3 on chip and were sustained above 2000 Ω · cm2 up to 10 days, which are the highest sustained TEER values reported in a microfluidic model. We evaluated the capacity of our microfluidic BBB model to be used for drug permeability studies using large molecules (FITC-dextrans) and model drugs (caffeine, cimetidine, and doxorubicin). Our analyses demonstrated that the permeability coefficients measured using our model were comparable to in vivo values. Our BBB-on-a-chip model closely mimics physiological BBB barrier functions and will be a valuable tool for screening of drug candidates. The residence time-based design of a microfluidic platform will enable integration with other organ modules to simulate multi-organ interactions on drug response. Biotechnol. Bioeng. 2017;114: 184-194. © 2016 Wiley Periodicals, Inc.

Efficient Generation of Skin Organoids from Pluripotent Cells via Defined Extracellular Matrix Cues and Morphogen Gradients in a Spindle-Shaped Microfluidic Device.

Pluripotent stem cell-derived skin organoids (PSOs) emerge as a developmental skin model that is self-organized into multiple components, such as hair follicles. Despite their impressive complexity, PSOs are currently generated in the absence of 3D extracellular matrix (ECM) signals and have several major limitations, including an inverted anatomy (e.g., epidermis inside/dermis outside). In this work, a method is established to generate PSOs effectively in a chemically-defined 3D ECM environment. After examining various dermal ECM molecules, it is found that PSOs generated in collagen -type I (COLI) supplemented with laminin 511 (LAM511) exhibit increased growth compared to conventional free-floating conditions, but fail to induce complete skin differentiation due in part to necrosis. This problem is addressed by generating the PSOs in a 3D bioprinted spindle-shaped hydrogel device, which constrains organoid growth longitudinally. This culture system significantly reduces organoid necrosis and leads to a twofold increase in keratinocyte differentiation and an eightfold increase in hair follicle formation. Finally, the system is adapted as a microfluidic device to create asymmetrical gradients of differentiation factors and improves the spatial organization of dermal and epidermal cells. This study highlights the pivotal role of ECM and morphogen gradients in promoting and spatially-controlling skin differentiation in the PSO framework.

A biopsy-sized 3D skin model with a perifollicular vascular plexus enables studying immune cell trafficking in the skin.

Human skin vasculature features a unique anatomy in close proximity to the skin appendages and acts as a gatekeeper for constitutive lymphocyte trafficking to the skin. Approximating such structural complexity and functionality in 3D skin models is an outstanding tissue engineering challenge. In this study, we leverage the capabilities of the digital-light-processing bioprinting to generate an anatomically-relevant and miniaturized 3D skin-on-a-chip (3D-SoC) model in the size of a 6 mm punch biopsy. The 3D-SoC contains a perfusable vascular network resembling the superficial vascular plexus of the skin and closely surrounding bioengineered hair follicles. The perfusion capabilities of the 3D-SoC enables the circulation of immune cells, and high-resolution imaging of the immune cell-endothelial cell interactions, namely tethering, rolling, and extravasation in real-time. Moreover, the vascular pattern in 3D-SoC captures the physiological range of shear rates found in cutaneous blood vessels and allows for studying the effect of shear rate on T cell trafficking. In 3D-SoC, as expected,in vitro-polarized T helper 1 (Th1) cells show a stronger attachment on the vasculature compared to naïve T cells. Both naïve and T cells exhibit higher retention in the low-shear zones in the early stages (<5 min) of T cell attachment. Interestingly, at later stages T cell retention rate becomes independent of the shear rate. The attached Th1 cells further transmigrate from the vessel walls to the extracellular space and migrate toward the bioengineered hair follicles and interfollicular epidermis. When the epidermis is not present, Th1 cell migration toward the epidermis is significantly hindered, underscoring the role of epidermal signals on T cell infiltration. Our data validates the capabilities of 3D-SoC model to study the interactions between immune cells and skin vasculature in the context of epidermal signals. The biopsy-sized 3D-SoC model in this study represents a new level of anatomical and cellular complexity, and brings us a step closer to generating a truly functional human skin with its tissue-specific vasculature and appendages in the presence of circulating immune cells.

Skin-on-a-chip technologies towards clinical translation and commercialization.

Skin is the largest organ of the human body which plays a critical role in thermoregulation, metabolism (e.g. synthesis of vitamin D), and protection of other organs from environmental threats, such as infections, microorganisms, ultraviolet radiation, and physical damage. Even though skin diseases are considered to be less fatal, the ubiquity of skin diseases and irritation caused by them highlights the importance of skin studies. Furthermore, skin is a promising means for transdermal drug delivery, which requires a thorough understanding of human skin structure. Current animal andin vitrotwo/three-dimensional skin models provide a platform for disease studies and drug testing, whereas they face challenges in the complete recapitulation of the dynamic and complex structure of actual skin tissue. One of the most effective methods for testing pharmaceuticals and modeling skin diseases are skin-on-a-chip (SoC) platforms. SoC technologies provide a non-invasive approach for examining 3D skin layers and artificially creating disease models in order to develop diagnostic or therapeutic methods. In addition, SoC models enable dynamic perfusion of culture medium with nutrients and facilitate the continuous removal of cellular waste to further mimic thein vivocondition. Here, the article reviews the most recent advances in the design and applications of SoC platforms for disease modeling as well as the analysis of drugs and cosmetics. By examining the contributions of different patents to the physiological relevance of skin models, the review underscores the significant shift towards more ethical and efficient alternatives to animal testing. Furthermore, it explores the market dynamics ofin vitroskin models and organ-on-a-chip platforms, discussing the impact of legislative changes and market demand on the development and adoption of these advanced research tools. This article also identifies the existing obstacles that hinder the advancement of SoC platforms, proposing directions for future improvements, particularly focusing on the journey towards clinical adoption.

Human skin-on-a-chip for mpox pathogenesis studies and preclinical drug evaluation.

Timely intervention of preventative and therapeutic measures abated a 2022 mpox global outbreak. However, the high transmissibility and unique pathological characteristics of mpox demand further investigation. Here, we discuss the potentials of human skin-on-a-chip as a valuable model for mpox disease evaluation, to achieve in-depth physiological understanding and desirable therapeutic predictive capabilities.

Pumped and pumpless microphysiological systems to study (nano)therapeutics.

Fluidic microphysiological systems (MPS) are microfluidic cell culture devices that are designed to mimic the biochemical and biophysical in vivo microenvironments of human tissues better than conventional petri dishes or well-plates. MPS-grown tissue cultures can be used for probing new drugs for their potential primary and secondary toxicities as well as their efficacy. The systems can also be used for assessing the effects of environmental nanoparticles and nanotheranostics, including their rate of uptake, biodistribution, elimination, and toxicity. Pumpless MPS are a group of MPS that often utilize gravity to recirculate cell culture medium through their microfluidic networks, providing some advantages, but also presenting some challenges. They can be operated with near-physiological amounts of blood surrogate (i.e., cell culture medium) that can recirculate in bidirectional or unidirectional flow patterns depending on the device configuration. Here we discuss recent advances in the design and use of both pumped and pumpless MPS with a focus on where pumpless devices can contribute to realizing the potential future role of MPS in evaluating nanomaterials. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

COVID-19 and pneumothorax, pneumomediastinum, subcutaneous emphysema: Analysis of risk factors.

Background: In this study, we aimed to analyze the risk factors of barotrauma in patients who were followed in the intensive care unit due to novel coronavirus disease 2019 (COVID-19) pneumonia. Methods: Between March 2020 and January 2021, a total of 261 patients (155 males, 106 females; mean age: 63.3±15.3 years; range, 11 to 91 years) who were followed in the intensive care unit due to COVID-19 pneumonia and were diagnosed with pneumothorax, pneumomediastinum, and subcutaneous emphysema were retrospectively analyzed. Demographics data of the patients, past and current medical history, clinical management, patient progress, and survival data were obtained from medical records of our hospital. Results: Twenty-seven of the patients were diagnosed with barotrauma. A total of 88.8% of the patients were followed with intubation. The development of pneumothorax, pneumomediastinum, and subcutaneous emphysema due to barotrauma was not dependent on sex, smoking/non-smoking status, using/not using corticosteroids, or comorbid diseases. There was a significant correlation between pneumothorax, pneumomediastinum, and subcutaneous emphysema development in intubated patients with different ventilator modes. Changing the ventilator mode from synchronized intermittent mandatory ventilation to airway pressure release ventilation increased the possibility of barotrauma by 15 times. Conclusion: Despite all lung-protective applications, barotrauma is a common complication, particularly in mechanically ventilated patients who have COVID-19 pneumonia with severe acute respiratory distress syndrome. Mechanical ventilator pressure modes should be patientspecific and followed carefully and frequently for the risk of barotrauma.

Engineering edgeless human skin with enhanced biomechanical properties.

Despite the advancements in skin bioengineering, 3D skin constructs are still produced as flat tissues with open edges, disregarding the fully enclosed geometry of human skin. Therefore, they do not effectively cover anatomically complex body sites, e.g., hands. Here, we challenge the prevailing paradigm by engineering the skin as a fully enclosed 3D tissue that can be shaped after a body part and seamlessly transplanted as a biological clothing. Our wearable edgeless skin constructs (WESCs) show enhanced dermal extracellular matrix (ECM) deposition and mechanical properties compared to conventional constructs. WESCs display region-specific cell/ECM alignment, as well as physiologic anisotropic mechanical properties. WESCs replace the skin in full-thickness wounds of challenging body sites (e.g., mouse hindlimbs) with minimal suturing and shorter surgery time. This study provides a compelling technology that may substantially improve wound care and suggests that the recapitulation of the tissue macroanatomy can lead to enhanced biological function.

Design and development of microbioreactors for long-term cell culture in controlled oxygen microenvironments.

The ability to control the oxygen level to which cells are exposed in tissue culture experiments is crucial for many applications. Here, we design, develop and test a microbioreactor (MBR) for long-term cell culture studies with the capability to accurately control and continuously monitor the dissolved oxygen (DO) level in the cell microenvironment. In addition, the DO level can be controlled independently from other cues, such as the viscous shear-stress acting on the cells. We first analyze the transport of oxygen in the proposed device and determine the materials and dimensions that are compatible with uniform oxygen tension and low shear-stress at the cell level. The device is also designed to culture a statistically significant number of cells. We use fully transparent materials and the overall design of the device is compatible with live-cell imaging. The proposed system includes real-time read-out of actual DO levels, is simple to fabricate at low cost, and can be easily expanded to control the concentration of other microenvironmental solutes. We performed control experiments in the absence of cells to demonstrate that the MBR can be used to accurately modulate DO levels ranging from atmospheric level to 1%, both under no flow and perfusion conditions. We also demonstrate cancer cell attachment and viability within the MBR. The proposed MBR offers the unprecedented capability to perform on-line measurement and analysis of DO levels in the microenvironment of adherent cultures and to correlate them with various cellular responses.

Microbioreactors to manipulate oxygen tension and shear stress in the microenvironment of vascular stem and progenitor cells.

The dynamics of dissolved oxygen (DO) and shear stress in the vasculature microenvironment play a major role in determining the fate of stem cells in adults and during early embryonic development. In this study, we present a microbioreactor (MBR) that provides independent control over oxygen tension and shear stress in cultures of stem and progenitor cell types. We first describe the design principles and use a model-driven approach for the optimization of the MBR geometry and operating conditions prior to its fabrication and assembly. We then demonstrate the utilization of the MBR for culturing adult human endothelial progenitors, human umbilical vein endothelial cells, and human embryonic stem cell-derived smooth muscle cells under different DO and shear stress levels.

Biomaterials and bioengineering to guide tissue morphogenesis in epithelial organoids.

Organoids are self-organized and miniatured in vitro models of organs and recapitulate key aspects of organ architecture and function, leading to rapid progress in understanding tissue development and disease. However, current organoid culture systems lack accurate spatiotemporal control over biochemical and physical cues that occur during in vivo organogenesis and fail to recapitulate the complexity of organ development, causing the generation of immature organoids partially resembling tissues in vivo. Recent advances in biomaterials and microengineering technologies paved the way for better recapitulation of organ morphogenesis and the generation of anatomically-relevant organoids. For this, understanding the native ECM components and organization of a target organ is essential in providing rational design of extracellular scaffolds that support organoid growth and maturation similarly to the in vivo microenvironment. In this review, we focus on epithelial organoids that resemble the spatial distinct structure and function of organs lined with epithelial cells including intestine, skin, lung, liver, and kidney. We first discuss the ECM diversity and organization found in epithelial organs and provide an overview of developing hydrogel systems for epithelial organoid culture emphasizing their key parameters to determine cell fates. Finally, we review the recent advances in tissue engineering and microfabrication technologies including bioprinting and microfluidics to overcome the limitations of traditional organoid cultures. The integration of engineering methodologies with the organoid systems provides a novel approach for instructing organoid morphogenesis via precise spatiotemporal modulation of bioactive cues and the establishment of high-throughput screening platforms.

Cellular Pathogenesis of Chemotherapy-Induced Peripheral Neuropathy: Insights From Drosophila and Human-Engineered Skin Models.

Chemotherapy-induced peripheral neuropathy (CIPN) is a highly prevalent and complex condition arising from chemotherapy cancer treatments. Currently, there are no treatment or prevention options in the clinic. CIPN accompanies pain-related sensory functions starting from the hands and feet. Studies focusing on neurons in vitro and in vivo models significantly advanced our understanding of CIPN pathological mechanisms. However, given the direct toxicity shown in both neurons and non-neuronal cells, effective in vivo or in vitro models that allow the investigation of neurons in their local environment are required. No single model can provide a complete solution for the required investigation, therefore, utilizing a multi-model approach would allow complementary advantages of different models and robustly validate findings before further translation. This review aims first to summarize approaches and insights from CIPN in vivo models utilizing small model organisms. We will focus on Drosophila melanogaster CIPN models that are genetically amenable and accessible to study neuronal interactions with the local environment in vivo. Second, we will discuss how these findings could be tested in physiologically relevant vertebrate models. We will focus on in vitro approaches using human cells and summarize the current understanding of engineering approaches that may allow the investigation of pathological changes in neurons and the skin environment.

Engineering human skin model innervated with itch sensory neuron-like cells differentiated from induced pluripotent stem cells.

Atopic dermatitis (AD), driven by interleukins (IL-4/IL-13), is a chronic inflammatory skin disease characterized by intensive pruritus. However, it is unclear how immune signaling and sensory response pathways cross talk with each other. We differentiated itch sensory neuron-like cells (ISNLCs) from iPSC lines. These ISNLCs displayed neural markers and action potentials and responded specifically to itch-specific stimuli. These ISNLCs expressed receptors specific for IL-4/IL-13 and were activated directly by the two cytokines. We successfully innervated these ISNLCs into full thickness human skin constructs. These innervated skin grafts can be used in clinical applications such as wound healing. Moreover, the availability of such innervated skin models will be valuable to develop drugs to treat skin diseases such as AD.

Unforeseen decreases in dissolved oxygen levels affect tube formation kinetics in collagen gels.

The availability of oxygen (O(2)) is a critical parameter affecting vascular tube formation. In this study, we hypothesize that dissolved oxygen (DO) levels in collagen gels change during the three-dimensional (3D) culture of human umbilical vein endothelial cells (HUVECs) in atmospheric conditions and that such changes affect the kinetics of tube formation through the production of reactive oxygen species (ROS). We demonstrate a decrease in O(2) tension during 3D cultures of HUVECs. Noninvasive measurements of DO levels during culture under atmospheric conditions revealed a profound decrease that reached as low as 2% O(2) at the end of 24 h. After media replacement, DO levels rose rapidly and equilibrated at ∼15% O(2), creating a reoxygenated environment. To accurately estimate DO gradients in 3D collagen gels, we developed a 3D mathematical model and determined the Michaelis-Menten parameters, V(max) and K(m), of HUVECs in collagen gels. We detected an increase in ROS levels throughout the culture period. Using diphenyliodonium to inhibit ROS production resulted in the complete inhibition of tube formation. Interference RNA studies further showed that hypoxia-inducible factors (HIFs)-1α and -2α are not involved in the formation of 3D tubes in collagen gels. We conclude that ROS affect the tubulogenesis process through HIFα-independent pathways, where the levels of ROS are influenced by the uncontrolled variations in DO levels. This study is the first demonstration of the critical and unexpected role of O(2) during 3D in vitro culture models of tubulogenesis in atmospheric conditions.

Quantitative Evaluation of Human Umbilical Vein and Induced Pluripotent Stem Cell-Derived Endothelial Cells as an Alternative Cell Source to Skin-Specific Endothelial Cells in Engineered Skin Grafts.

Objective: We compared the capability of human umbilical vein endothelial cells (HUVECs), induced pluripotent stem cell (iPSC)-derived endothelial cells (iECs), and human dermal blood endothelial cells (HDBECs) to effectively vascularize engineered human skin constructs (HSCs) in vitro and on immunodeficient mice. Approach: We quantified the angiogenesis within HSCs both in vitro and in vivo through computational analyses of immunofluorescent (IF) staining. We assayed with real-time quantitative PCR (RT-qPCR) the expression of key endothelial, dermal, and epidermal genes in 2D culture and HSCs. Epidermal integrity and proliferation were also evaluated through haematoxylin and eosin staining, and IF staining. Results: IF confirmed iEC commitment to endothelial phenotype. RT-qPCR showed HUVECs and iECs immaturity compared with HDBECs. In vitro, the vascular network extension was comparable for HDBECs and HUVECs despite differences in vascular diameter, whereas iECs formed unorganized rudimentary tubular structures. In vivo, all ECs produced discrete vascular networks of varying dimensions. HUVECs and HDBECs maintained a higher proliferation of basal keratinocytes. HDBECs had the best impact on extracellular matrix expression, and epidermal proliferation and differentiation. Innovation: To our knowledge, this study represents the first direct and quantitative comparison of HDBECs, HUVECs, and iECs angiogenic performance in HSCs. Conclusions: Our data indicate that HUVECs and iECs can be an alternative cell source to HDBEC to promote the short-term viability of prevascularized engineered grafts. Nevertheless, HDBECs maintain their capillary identity and outperform other EC types in promoting the maturation of the dermis and epidermis. These intrinsic characteristics of HDBECs may influence the long-term function of skin grafts.

Adaptation to oxygen deprivation in cultures of human pluripotent stem cells, endothelial progenitor cells, and umbilical vein endothelial cells.

Hypoxia plays an important role in vascular development through hypoxia-inducible factor-1alpha (HIF-1alpha) accumulation and downstream pathway activation. We sought to explore the in vitro response of cultures of human embryonic stem cells (hESCs), induced pluripotent stem cells (iPSCs), human endothelial progenitor cells (hEPCs), and human umbilical cord vein endothelial cells (HUVECs) to normoxic and hypoxic oxygen tensions. We first measured dissolved oxygen (DO) in the media of adherent cultures in atmospheric (21% O(2)), physiological (5% O(2)), and hypoxic oxygen conditions (1% O(2)). In cultures of both hEPCs and HUVECs, lower oxygen consumption was observed when cultured in 1% O(2). At each oxygen tension, feeder-free cultured hESCs and iPSCs were found to consume comparable amounts of oxygen. Transport analysis revealed that the oxygen uptake rate (OUR) of hESCs and iPSCs decreased distinctly as DO availability decreased, whereas the OUR of all cell types was found to be low when cultured in 1% O(2), demonstrating cell adaptation to lower oxygen tensions by limiting oxygen consumption. Next, we examined HIF-1alpha accumulation and the expression of target genes, including VEGF and angiopoietins (ANGPT; angiogenic response), GLUT-1 (glucose transport), BNIP3, and BNIP3L (autophagy and apoptosis). Accumulations of HIF-1alpha were detected in all four cell lines cultured in 1% O(2). Corresponding upregulation of VEGF, ANGPT2, and GLUT-1 was observed in response to HIF-1alpha accumulation, whereas upregulation of ANGPT1 was detected only in hESCs and iPSCs. Upregulation of BNIP3 and BNIP3L was detected in all cells after 24-h culture in hypoxic conditions, whereas apoptosis was not detectable using flow cytometry analysis, suggesting that BNIP3 and BNIP3L can lead to cell autophagy rather than apoptosis. These results demonstrate adaptation of all cell types to hypoxia but different cellular responses, suggesting that continuous measurements and control over oxygen environments will enable us to guide cellular responses.

Recapitulating T cell infiltration in 3D psoriatic skin models for patient-specific drug testing.

Drug screening studies for inflammatory skin diseases are currently performed using model systems that only partially recapitulate human diseased skin. Here, we developed a new strategy to incorporate T cells into human 3D skin constructs (HSCs), which enabled us to closely monitor and quantitate T cell responses. We found that the epidermis promotes the activation and infiltration of T cells into the skin, and provides a directional cue for their selective migration towards the epidermis. We established a psoriatic HSC (pHSC) by incorporating polarized Th1/Th17 cells or CCR6+CLA+ T cells derived from psoriasis patients into the constructs. These pHSCs showed a psoriatic epidermal phenotype and characteristic cytokine profiles, and responded to various classes of psoriasis drugs, highlighting the potential utility of our model as a drug screening platform. Taken together, we developed an advanced immunocompetent 3D skin model to investigate epidermal-T cell interactions and to understand the pathophysiology of inflammatory skin diseases in a human-relevant and patient-specific context.