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Journal of Radiation Research May 2008Apoptosis plays an important role in eliminating cells from populations when cells have been exposed to UV irradiation and damaged. Studies of cells in culture have...
Apoptosis plays an important role in eliminating cells from populations when cells have been exposed to UV irradiation and damaged. Studies of cells in culture have provided some details of the mechanisms involved when stress response genes act after exposure to UV irradiation and other environmental stresses. However, little is known about the responses of intact sections of human skin growing in organ culture to UV irradiation. In the work reported here, it was found that the response of organ-cultured human skin after exposure to UV irradiation is different than the response of cultured cells. At wavelengths below 300 nm, the action spectrum obtained from organ-cultured skin samples showed a lower sensitivity than that observed at 300 nm, indicating that the overlying stratum corneum and upper epidermal cell layers had probably caused a selective absorption of incident UV radiation at some wavelengths. At 3 hours after UV irradiation, p53 was phosphorylated at Ser 15 and Ser 46, and accumulated in the cell nuclei, notably after exposure to 280-320 nm wavelengths. Accumulations of Bax, active Caspase-3 and cleaved PARP were detected in apoptotic cells at 24 hours post-exposure, along with a reduction of Bcl-2 levels, notably after exposure to 300-365 nm light. This difference in apoptotic responses may result from the characteristics of the different irradiation wavelengths used, and from details in the skin's structure. The data obtained in this study using an organ-culture system utilized direct measurements of the biological effects of different wavelengths of UV lights.
Topics: Adult; Apoptosis; Female; Humans; Organ Culture Techniques; Skin; Time Factors; Tumor Suppressor Protein p53; Ultraviolet Rays
PubMed: 18311036
DOI: 10.1269/jrr.07106 -
American Journal of Physiology. Cell... Sep 2020Bioprinting aims to direct the spatial arrangement in three dimensions of cells, biomaterials, and growth factors. The biofabrication of clinically relevant constructs... (Review)
Review
Bioprinting aims to direct the spatial arrangement in three dimensions of cells, biomaterials, and growth factors. The biofabrication of clinically relevant constructs for the repair or modeling of either diseased or damaged tissues is rapidly advancing, resulting in the ability to three-dimensional (3D) print biomimetic platforms which imitate a large number of tissues in the human body. Primary tissue-specific cells are typically isolated from patients and used for the fabrication of 3D models for drug screening or tissue repair purposes. However, the lack of resilience of these platforms, due to the difficulties in harnessing, processing, and implanting patient-specific cells can limit regeneration ability. The printing of stem cells obviates these hurdles, producing functional in vitro models or implantable constructs. Advancements in biomaterial science are helping the development of inks suitable for the encapsulation and the printing of stem cells, promoting their functional growth and differentiation. This review specifically aims to investigate the most recent studies exploring innovative and functional approaches for the printing of 3D constructs to model disease or repair damaged tissues. Key concepts in tissue physiology are highlighted, reporting stem cell applications in biofabrication. Bioprinting technologies and biomaterial inks are listed and analyzed, including recent advancements in biomaterial design for bioprinting applications, commenting on the influence of biomaterial inks on the encapsulated stem cells. Ultimately, most recent successful efforts and clinical potentials for the manufacturing of functional physiological tissue substitutes are reported here, with a major focus on specific tissues, such as vasculature, heart, lung and airways, liver, bone and muscle.
Topics: Bioprinting; Cell Differentiation; Humans; Ink; Organ Culture Techniques; Stem Cells; Tissue Engineering
PubMed: 32639873
DOI: 10.1152/ajpcell.00124.2020 -
Developmental Biology Dec 2019The current strategy to preserve fertility of male prepubertal cancer patients consists of cryopreservation of a testicular tissue biopsy containing spermatogonial stem...
The current strategy to preserve fertility of male prepubertal cancer patients consists of cryopreservation of a testicular tissue biopsy containing spermatogonial stem cells (SSCs). While in humans, fertility restoration strategies from prepubertal testicular tissues are still under investigation and have not yet resulted in complete germ cell differentiation, in mice various studies have described production of sperm and offspring through testicular organ culture and transplantation of in vitro propagated SSCs. Organ culture has shown to be successful in generating mature spermatozoa when using testicular fragments from various mouse strains, including CD1 and C57BL/6 J. Conversely, in vitro proliferation of SSCs from C57BL/6 J mice is highly inefficient when compared to other strains such as DBA2 or hybrid mice of C57BL/6 J and DBA2 with 75% C57BL/6 J background (B6D2F2). In this study, we investigated in vitro spermatogenesis by organ culture using testicular tissue from C57BL/6 J and B6D2F2 mice. Whereas spermatogenesis was initiated and completed in C57BL/6 J fragments, it could not be effectively supported in B6D2F2 testicular tissue. While maturation of Sertoli cells and Leydig cells functionality appeared to be identical between the two strains, in B6D2F2 tissue spermatogenesis did not proceed past the spermatocyte step, followed by a rapid decline of the number of all germ cells in the fragments. This suggests that the spermatogenic potential in vitro is dependent on specialized sites in the genome and therefore the organ culture conditions suboptimal for some strains of mice.
Topics: Adult Germline Stem Cells; Animals; Cell Differentiation; Cell Proliferation; Cryopreservation; Genetic Background; Male; Mice; Mice, Inbred Strains; Organ Culture Techniques; Sexual Maturation; Spermatogenesis; Spermatogonia; Spermatozoa; Testis
PubMed: 31421080
DOI: 10.1016/j.ydbio.2019.08.007 -
Theranostics 2018Epithelial cancer grows in a microenvironment that comprises tumour, stroma, and immune cells. A three-dimensional (3D) culture model might be able to mimic the tumour...
Epithelial cancer grows in a microenvironment that comprises tumour, stroma, and immune cells. A three-dimensional (3D) culture model might be able to mimic the tumour microenvironment ; therefore, we developed a new 3D epithelial cancer model using cell-sheet engineering and compared the results of treatment with several chemotherapeutic drugs among the 3D cell-sheet model, spheroid culture, and 2D cell culture. The cell sheet comprised keratinocytes and a plasma fibrin matrix containing fibroblasts. Cancer spheroids with or without cancer-associated fibroblasts (CAFs) were interposed between the keratinocytes and fibrin layer. Cell growth, viability, and hypoxia were measured using the cell counting kit-8, LIVE/DEAD assay, and propidium iodide and LOX-1 staining. The morphology, invasion, and mRNA and protein expression were compared among the different cell culture models. Enhanced resistance to sorafenib and cisplatin by cancer spheroids and CAFs was more easily observed in the 3D than in the 2D model. Invasion by cancer-CAF spheroids into the fibrin matrix was more clearly observed in the 3D cell sheet. The expansion of viable cancer cells increased in the 3D cell sheet, particularly in those with CAFs, which were significantly inhibited by treatment with 10 μM sorafenib or 20 μM cisplatin ( < 0.05). TGF-β1, N-cadherin, and vimentin mRNA and protein levels were higher in the 3D cell-sheet model. The 3D cell sheet-based cancer model could be applied to observation of epithelial cancer growth and invasion and to anticancer drug testing.
Topics: Antineoplastic Agents; Drug Evaluation, Preclinical; Epithelium; Humans; Neoplasms, Glandular and Epithelial; Organ Culture Techniques; Spheroids, Cellular
PubMed: 30083273
DOI: 10.7150/thno.26439 -
The Journal of Experimental Medicine Apr 2021In a 1937 issue of JEM, Carrel (1937. J. Exp. Med.https://doi.org/10.1084/jem.65.4.515) described a technique for culturing whole living organs outside the body. Here,...
In a 1937 issue of JEM, Carrel (1937. J. Exp. Med.https://doi.org/10.1084/jem.65.4.515) described a technique for culturing whole living organs outside the body. Here, Ingber reviews how this work led to a series of scientific, engineering, and medical breakthroughs that continue to this day.
Topics: Animals; History, 20th Century; Humans; Infusion Pumps; Lab-On-A-Chip Devices; Male; Mice; Models, Animal; Organ Culture Techniques; Organ Transplantation
PubMed: 33710255
DOI: 10.1084/jem.20201756 -
Integrative Biology : Quantitative... Apr 2015Advances in maintaining multiple human tissues on microfluidic platforms has led to a growing interest in the development of microphysiological systems for drug... (Review)
Review
Advances in maintaining multiple human tissues on microfluidic platforms has led to a growing interest in the development of microphysiological systems for drug development studies. Determination of the proper design principles and scaling rules for body-on-a-chip systems is critical for their strategic incorporation into physiologically based pharmacokinetic (PBPK)/pharmacodynamic (PD) model-aided drug development. While the need for a functional design considering organ-organ interactions has been considered, robust design criteria and steps to build such systems have not yet been defined mathematically. In this paper, we first discuss strategies for incorporating body-on-a-chip technology into the current PBPK modeling-based drug discovery to provide a conceptual model. We propose two types of platforms that can be involved in the different stages of PBPK modeling and drug development; these are μOrgans-on-a-chip and μHuman-on-a-chip. Then we establish the design principles for both types of systems and develop parametric design equations that can be used to determine dimensions and operating conditions. In addition, we discuss the availability of the critical parameters required to satisfy the design criteria, consider possible limitations for estimating such parameter values and propose strategies to address such limitations. This paper is intended to be a useful guide to the researchers focused on the design of microphysiological platforms for PBPK/PD based drug discovery.
Topics: Biological Assay; Drug Design; Equipment Design; Equipment Failure Analysis; Flow Injection Analysis; Humans; Lab-On-A-Chip Devices; Models, Biological; Organ Culture Techniques; Pharmacokinetics; Pharmacology
PubMed: 25739725
DOI: 10.1039/c4ib00292j -
Infection and Immunity Nov 2018Tissues and organs provide the structural and biochemical landscapes upon which microbial pathogens and commensals function to regulate health and disease. While flat... (Review)
Review
Tissues and organs provide the structural and biochemical landscapes upon which microbial pathogens and commensals function to regulate health and disease. While flat two-dimensional (2-D) monolayers composed of a single cell type have provided important insight into understanding host-pathogen interactions and infectious disease mechanisms, these reductionist models lack many essential features present in the native host microenvironment that are known to regulate infection, including three-dimensional (3-D) architecture, multicellular complexity, commensal microbiota, gas exchange and nutrient gradients, and physiologically relevant biomechanical forces (e.g., fluid shear, stretch, compression). A major challenge in tissue engineering for infectious disease research is recreating this dynamic 3-D microenvironment (biological, chemical, and physical/mechanical) to more accurately model the initiation and progression of host-pathogen interactions in the laboratory. Here we review selected 3-D models of human intestinal mucosa, which represent a major portal of entry for infectious pathogens and an important niche for commensal microbiota. We highlight seminal studies that have used these models to interrogate host-pathogen interactions and infectious disease mechanisms, and we present this literature in the appropriate historical context. Models discussed include 3-D organotypic cultures engineered in the rotating wall vessel (RWV) bioreactor, extracellular matrix (ECM)-embedded/organoid models, and organ-on-a-chip (OAC) models. Collectively, these technologies provide a more physiologically relevant and predictive framework for investigating infectious disease mechanisms and antimicrobial therapies at the intersection of the host, microbe, and their local microenvironments.
Topics: Cellular Microenvironment; History, 20th Century; History, 21st Century; Host-Pathogen Interactions; Humans; Intestinal Mucosa; Models, Biological; Organ Culture Techniques; Organoids; Tissue Engineering
PubMed: 30181350
DOI: 10.1128/IAI.00282-18 -
Acta Ophthalmologica Dec 2017To assess the influence of donor, environment and storage factors on the contamination rate of organ-cultured corneas, to consider the microbiological species causing...
PURPOSE
To assess the influence of donor, environment and storage factors on the contamination rate of organ-cultured corneas, to consider the microbiological species causing corneal contamination and to investigate the corresponding sensitivities.
METHODS
Data from 1340 consecutive donor corneas were analysed retrospectively. Logistic regression analysis was used to assess the influence of different factors on the contamination rate of organ-cultured corneas for transplantation.
RESULTS
The mean annual contamination rate was 1.8 ± 0.4% (range: 1.3-2.1%); 50% contaminations were of fungal origin with exclusively Candida species, and 50% contaminations were of bacterial origin with Staphylococcus species being predominant. The cause of donor death including infection and multiple organ dysfunction syndrome increased the risk of bacterial or fungal contamination during organ culture (p = 0.007 and p = 0.014, respectively). Differentiating between septic and aseptic donors showed an increased risk of contamination for septic donors (p = 0.0020). Mean monthly temperature including warmer months increased the risk of contamination significantly (p = 0.0031). Sex, donor age, death to enucleation, death to corneoscleral disc excision and storage time did not increase the risk of contamination significantly.
CONCLUSION
The genesis of microbial contamination in organ-cultured donor corneas seems to be multifactorial. The main source of fungal or bacterial contamination could be resident species from the skin flora. The rate of microbial contamination in organ-cultured donor corneas seems to be dependent on the cause of donor death and mean monthly temperature.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteria; Cornea; Corneal Transplantation; Culture Media; Eye Banks; Eye Infections, Bacterial; Female; Follow-Up Studies; Germany; Humans; Male; Middle Aged; Organ Culture Techniques; Organ Preservation; Prevalence; Retrospective Studies; Tissue Donors; Young Adult
PubMed: 28321999
DOI: 10.1111/aos.13375 -
Trends in Biotechnology Feb 2017Drug-induced liver injury (DILI) remains a leading cause of drug withdrawal from human clinical trials or the marketplace. Owing to species-specific differences in liver... (Review)
Review
Drug-induced liver injury (DILI) remains a leading cause of drug withdrawal from human clinical trials or the marketplace. Owing to species-specific differences in liver pathways, predicting human-relevant DILI using in vitro human liver models is crucial. Microfabrication tools allow precise control over the cellular microenvironment towards stabilizing liver functions for weeks. These tools are used to engineer human liver models with different complexities and throughput using cell lines, primary cells, and stem cell-derived hepatocytes. Including multiple human liver cell types can mimic cell-cell interactions in specific types of DILI. Finally, organ-on-a-chip models demonstrate how drug metabolism in the liver affects multi-organ toxicities. In this review we survey engineered human liver platforms within the needs of different phases of drug development.
Topics: Animals; Drug Evaluation, Preclinical; Equipment Design; Humans; Liver; Liver, Artificial; Organ Culture Techniques; Tissue Engineering; Tissue Scaffolds
PubMed: 27592803
DOI: 10.1016/j.tibtech.2016.08.001 -
Journal of Visualized Experiments : JoVE Feb 2019The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two dimensional (2D) and...
The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two dimensional (2D) and three dimensional (3D) culture has generated a wealth of information not only about corneal biology but also about wound healing, myofibroblast biology, and scarring in general. The goal of the protocol is an assay system for quantifying myofibroblast development, which characterizes scarring. We demonstrate a corneal organ culture ex vivo model using pig eyes. In this anterior keratectomy wound, corneas still in the globe are wounded with a circular blade called a trephine. A plug of approximately 1/3 of the anterior cornea is removed including the epithelium, the basement membrane, and the anterior part of the stroma. After wounding, corneas are cut from the globe, mounted on a collagen/agar base, and cultured for two weeks in supplemented-serum free medium with stabilized vitamin C to augment cell proliferation and extracellular matrix secretion by resident fibroblasts. Activation of myofibroblasts in the anterior stroma is evident in the healed cornea. This model can be used to assay wound closure, the development of myofibroblasts and fibrotic markers, and for toxicology studies. In addition, the effects of small molecule inhibitors as well as lipid-mediated siRNA transfection for gene knockdown can be tested in this system.
Topics: Animals; Cornea; Disease Models, Animal; Organ Culture Techniques; Swine; Transfection
PubMed: 30829330
DOI: 10.3791/58562