Dynamic Culture Research Articles

Differentiating erythroblasts adapt to mechanical stimulation by upregulation of cholesterol biosynthesis via S1P/SREBP-induced HMGCR expression

Understanding how mechanical stress affects erythropoiesis is crucial to produce transfusable erythrocytes in fluid-turbulent bioreactors. We investigated the effects of shear-stress on differentiating CD49d+CD235a+ primary human erythroblasts (EBL) at molecular, cellular, and functional level. Shear-stress, at differentiation onset, enhanced EBL maturation and induced upregulation of genes regulating cholesterol/lipids biosynthesis, causing changes in cell lipid composition. Of note, the osmotic resistance, and the expression of 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme of the cholesterol biosynthesis pathway, were higher in dynamic cultures. Inhibition of the S1P-induced proteolytic cleavage, activating SREBPs, led to abrogation of HMCGR expression, and loss of EBL in dynamic cultures, similar to lovastatin administration. This data reveals a role for the S1P-SREBP-HMGCR-axis in the regulation of shear-stress induced adaptation during erythropoiesis, shedding light into mechanisms that will assist the upscaling of erythroid differentiation into bioreactors. Moreover, as shear-stress on hematopoietic cells occurs within the bone-marrow, these results introduce a novel signalling axis in the transduction pathways controlling erythropoiesis.

Culturing 3D chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds in a dynamic environment enhances osteochondral reconstruction.

Bioreactor can provide a dynamic culture environment for the in vitro construction of osteochondral tissue engineering. They facilitate more efficient exchange of nutrients and provide mechanical and other beneficial stimulation. Previous findings demonstrated that rotary flask (RF) bioreactor, rotary cell culture system (RCCS), or electromagnetic field (EMF) mediated scaffold culture could create a favorable dynamic environment for osteochondral tissue engineering. However, it is still unclear whether there is an optimal bioreactor or if bioreactors under multi-parameter coupling conditions are conducive to osteochondral tissue engineering. Based on this, the application of static T-flask (TF), RF, RCCS, and coupling environment of RCCS and EMF for osteochondral tissue engineering were systematically compared. The results showed that the RCCS/EMF culture system achieved the highest level of cellular proliferation and directed differentiation. Compared with the static culture group, the expression levels of chondrogenic factors of Sox9, Col II, and ACAN and osteogenic factors of Runx2, OCN, and Col I in RCCS/EMF culture system were 2.90±0.10, 3.53±0.05, 3.15±0.08, 7.16±0.15, 5.01±0.21 and 3.99±0.17 folds, respectively. The 'Active osteochondral' constructs (The construct is composed of chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds) were prepared under different culture modes in vitro and implanted into the femoral condylar defect of New Zealand rabbits. After 12weeks, all culture modes could effectively promote the repair of osteochondral defects, in which the RCCS/EMF intervention had the best effect on the in vivo in-situ repair of osteochondral tissues. Furthermore, the fabricated cartilage and subchondral bone in the RCCS/EMF treatment group were most similar to the surrounding natural tissues, providing a new therapeutic idea for osteochondral tissue engineering.

다문화적 결합체에서의 풍류문화의 관계성 -유기체적 관점에서-

This study aims to explore the relatedness of Korean Pungryu culture in addressing issues of discrimination, inequality, and the growing lack of ethnic and cultural communication in contemporary multicultural societies, where ethnic, linguistic, and cultural deterritorialization is accelerating. First, this paper identifies the cognitive errors inherent in multiculturalism rooted in Western substance philosophy as a key factor underlying the lack of communication in multicultural life and the inequality and discrimination faced by minority cultures. Second, it argues that Pungryu culture offers a valuable tool for transforming the perception and thought patterns of Western multiculturalism due to its shared ontological organic characteristics with Whitehead's concept of ‘nexus’ and the Buddhist principle of ‘연기’(Pratityasamutpāda). Third, by examining the characteristics of '포함삼교'(Pohamsamgyo) and ’접화군생'(Chophwagoonsaeng) manifested in the artistic and behavioral modalities of Pungryu culture, this study demonstrates that Pungryu culture is not an immutable, windowless monad but a dynamic culture of organic relationships that generates the meaning of existence through mutually immanent connections. These findings suggest that the organic relationality of Pungryu culture has the potential to foster a symbiotic multicultural nexus in multicultural societies, grounded in cultural relativism. can generate a symbiotic multicultural nexus in the life of a multicultural society based on cultural relativism.

Unlocking Gen-Z employee potential: the role of strategic leadership and organizational culture

This study aims to examine the role of strategic leadership and organizational culture in optimizing the potential of Generation Z (Gen-Z) employees in the modern work environment. Gen-Z has unique characteristics, such as high adaptability to technology and a strong desire to achieve work-life balance, which requires a more inclusive and dynamic leadership approach and organizational culture. Through a quantitative approach, this study uses the Partial Least Squares Structural Equation Modeling (PLS-SEM) method to analyze the relationship between strategic leadership and organizational culture on the performance of Gen-Z employees. Data were obtained from a survey of 96 Gen-Z employees working in various industrial sectors. The results of the study indicate that strategic leadership involving open communication, innovation, and long-term vision does not have a positive and significant effect on Gen-Z motivation and performance. In addition, an organizational culture that supports collaboration, flexibility, and personal development has also been shown to play an important role in improving their performance. This study underlines the importance of the role of strategic leaders in creating an organizational culture that is aligned with the expectations and values ​​of Generation Z, so that they can optimize their potential to the fullest. The practical implications of this study provide guidance for managers and organizational policy makers to design effective leadership strategies in the era of a multigenerational workforce.

A pump-free microfluidic co-culture system for investigating NK cell-tumor spheroid interactions in flow conditions

Natural killer (NK) cells are pivotal in immunotherapy due to their potent tumor-targeting capabilities. However, accessible in vitro 3D dynamic models for evaluating Tumor Infiltrating Natural Killer Cells (TINKs) remain scarce. This study addresses this gap by developing a novel pump-free microfluidic chip to investigate the interactions between NK-92 cells and prostate DU 145 tumor spheroids. The platform facilitates the separation of free NKs and TINKs for subtype characterization. The design integrates multiple planes with a multi-layer paper scaffold to accommodate tumor spheroids, allowing NK-92 cells to traverse Matrigel-coated barriers that mimic the extracellular matrix. The dual-channel pump-free device enables unidirectional circulation of NK-92 cells, allowing analysis of tumor spheroid movement and NK-92 cell interactions under flow conditions. Results demonstrate continuous fluid circulation in the dual-channel device by rocking the platform at tilt angles of 21° and 15°. Tumor spheroids show- enhanced migration under flow conditions compared to static culture. Although spheroids recruit slightly more NK-92 cells under flow conditions, CD56 and CD16 receptor expression on IL-2-activated free NK-92 cells and tumor-infiltrating NK-92 cells matches in vivo patterns in dynamic cultures. These findings suggest that tumor cells and fluid dynamics significantly influence NK cell subtypes. This pump-free microfluidic platform is a functional tool for simulating and studying immune cell-tumor interactions, providing valuable insights into NK cell dynamics with tumor spheroids in physiologically relevant environments.

Static and dynamic cell culture of small caliber bilayer vascular grafts electrospun from polycaprolactone

Developing a suitable vascular graft to replace damaged small-caliber vessels and promote tissue regeneration is a critical challenge. This study focuses on bilayer polycaprolactone (PCL) grafts, fabricated by electrospinning, with both randomly distributed and radially oriented fibers. The analysis covers surface morphology, fiber diameter, pore size, cellular behavior, and biodegradability. Human umbilical vein endothelial cells (HUVECs) show an impressive viability of 142.2% after 7 days, while umbilical artery smooth muscle cells (UASMCs) exhibit 112.6%. Fluorescent microscopy indicates a higher viability of HUVECs over UASMCs. On the other hand, less than 10% of HUVECs and less than 5% of UASMCs undergo cell death within 7 days. Biodegradation analysis over 12 months shows a significant weight loss of 65–70% for both types of fiber arrangements. A custom-designed bioreactor enables dynamic cell culture, revealing comparable activity to static cultures. In the dynamic cell culture environment, HUVECs maintain high viability and display robust proliferation at both the 4th and 7th days, supporting the results observed in static cell cultures. These findings underscore the significant potential of bilayer PCL grafts in advancing the field of blood vessels, offering promising avenues for the development of functional vascular replacements with enhanced regenerative capabilities.

Abstract 4124354: Transplantation of vascularized cardiac microtissue derived from human iPS cells improves impaired electrical conduction capacity in a porcine myocardial injury model

Background: To realize efficient regenerative medicine using human iPS cell (hiPSC)-derived cardiac tissue, it is necessary to achieve electrical synchronization between the graft and the host heart and to improve conduction disturbances in the impaired heart. In this study, we aimed to demonstrate that the transplantation of hiPSC-derived vascularized cardiac tissue can improve these conduction disturbances using a porcine myocardial injury model. Methods: We prepared cell sheet-shaped vascularized cardiac microtissue (VCM) by seeding cardiomyocytes, endothelial cells, and vascular mural cells differentiated from hiPSCs onto temperature-responsive culture plates and thickening them using dynamic rocking culture. We induced myocardial injury (MI) via epicardial cryoablation in immunosuppressed crown minipigs and transplanted the VCMs immediately after MI induction, covering the cryoinjury-induced MI area. The pigs underwent epicardial electroanatomic mapping under sinus rhythm and epicardial pacing, both immediately before and one week after MI induction, while using amiodarone. Differences in myocardial voltages and conduction velocities were assessed between VCM and sham groups (N=3 in each group). After electroanatomic analysis, the hearts were harvested and subjected to histological examination. Results: One week after MI induction, mean voltages at the MI site decreased in both groups during sinus rhythm, remote site pacing, and combined remote and MI site pacing (11.05 to 1.74 mV, 14.26 to 3.44 mV, and 15.61 to 3.67 mV, respectively, in the VCM group; and 8.72 to 2.70 mV, 19.64 to 3.64 mV, and 14.66 to 1.96 mV, respectively, in the Sham group). Mean voltages at the remote site also decreased in both groups during the same conditions (12.57 to 4.53 mV, 10.61 to 3.38 mV, and 19.56 to 5.85 mV, respectively, in the VCM group; and 8.75 to 6.03 mV, 14.15 to 5.79 mV, and 13.67 to 6.23 mV, respectively, in the Sham group). The mean conduction velocity between the remote and MI sites was numerically higher in the VCM group compared to the Sham group (2.84 m/s vs. 1.74 m/s, respectively). Histological examination confirmed that in the VCM transplantation group, the VCM remained intact, completely covering the MI area. Conclusions: The transplantation of VCM showed a tendency to improve conduction disturbances in the porcine MI model. This suggests that the graft may synchronize with the host and function mechanically after cell transplantation.

In Vitro Spermatogenesis on Human Decellularized Testicular Matrix Plates Following Exosome Treatment in a Dynamic Culture System.

Testicular tissue engineering for in vitro spermatogenesis aims to restore fertility, focusing on challenges like efficiency, ethical concerns, and the need for a deeper biological understanding. The use of decellularized scaffolds led to better cell seeding and differentiation, and exosomes led to enhanced spermatogenesis. Also, the dynamic culture systems are being explored to replicate in vivo conditions more accurately. In this study, we aimed to utilize a perfusion mini-bioreactor for the dynamic culture of mouse spermatogonial stem cells on decellularized testicular matrix plates supplemented with exosomes. Our goal was to assess the progression of the spermatogenesis process through histological, immunohistochemical, and molecular analyses over four weeks. Human testicular tissues were decellularized using 1% sodium dodecyl sulfate and were then fabricated into thin plates using a cryostat. Sertoli and spermatogonial stem cells were isolated from neonate mouse testis and seeded onto the decellularized testicular matrix plates. A mini-perfusion bioreactor was employed to create dynamic culture conditions. Also, MSCs-derived exosomes were introduced to the culture medium, alone or in combination with a spermatogenic medium containing numerous chemical factors. The histological, IHC, and molecular analyses were performed at the end of the experiment. Our decellularization procedure successfully preserved the ECM components, while eliminating native cells. The isolated cells expressed PLZF and VIMENTIN markers, confirming the presence of SSCs and Sertoli cells. The seeded scaffolds exhibited proper homing, viability, proliferation, and differentiation of the cells towards in vitro spermatogenesis. Also, exosome treatment is capable of enhancing the spermatogenic potential of SSCs. Our findings indicate that the dynamic culture system significantly promoted the proliferation and differentiation of SSCs into mature spermatozoa. The use of exosomes further enhanced these effects, as evidenced by improved cellular viability, reduced apoptosis, and advanced spermatogenesis to the elongated spermatid stage. The combined treatment of exosomes and spermatogenic medium showed a synergistic effect, yielding superior outcomes in terms of sperm cell maturity and functionality. This study underscores the potential of combining decellularized testicular matrices with exosome therapy in a dynamic culture set up to advance the field of reproductive biology and fertility restoration.

Personalized CZA-ATM dosing against an XDR E. coli in liver transplant patients; the application of the in vitro hollow fiber system.

A patient with an extensively drug-resistant (XDR) New Delhi metallo-β-lactamase (NDM) and oxacillinase (OXA-48) producing Escherichia coli (E. coli) infection was awaiting orthotopic liver transplant. There is no standardized antibiotic prophylaxis regimen; however, in line with the Infectious Diseases Society of America guidance, an antibiotic prophylactic regimen of ceftazidime-avibactam 2.5g TDS with aztreonam 2g three times a day (TDS) IV was proposed. The hollow fiber system (HFS) was applied to inform the individualized pharmacodynamic outcome likelihood prior to prophylaxis. A 4-log reduction in CFU/mL in the first 10 h of the regimen exposure was observed; however, the killing dynamics were slow and six 8-hourly infusions were required to reduce bacterial cells to below the limit of quantification. Thus, the HFS supported the use of the regimen for infection clearance; however, it highlighted the need for several infusions. Standard local practice is to administer prophylaxis antibiotics at induction of orthotopic liver transplantation (OLT); however, the HFS provided data to rationalize earlier dosing. Therefore, the patient was dosed at 24 h prior to their OLT induction and subsequently discharged 8 days after surgery. The HFS provides a dynamic culture solution for informing individualized medicine by testing antibiotic combinations and exposures against the bacterial isolates cultured from the patient's infection. .

High paracrine activity of hADSCs cartilage microtissues inhibits extracellular matrix degradation and promotes cartilage regeneration

Due to its unique structure, articular cartilage has limited self-repair capacity. Microtissues are tiny tissue clusters that can mimic the function of target organs or tissues. Using cells alone for microtissue construction often results in the formation of necrotic cores. However, the extracellular matrix (ECM) of native cartilage can provide structural support and is an ideal source of microcarriers. Autologous adipose-derived mesenchymal stem cells (ADSCs) and bone marrow mesenchymal stem cells (BMSCs) are widely used in cartilage tissue engineering. In this study, we fabricated microcarriers and compared the behavior of two homologous cell types in the microcarrier environment. The microcarrier environment highlighted the advantages of ADSCs and promoted the proliferation and migration of these cells. Then, ADSCs microtissues (ADSCs-MT) and BMSCs microtissues (BMSCs-MT) were fabricated using a three-dimensional dynamic culture system. In vitro and in vivo experiments verified that the cartilage regeneration ability of ADSCs-MT was significantly superior to that of BMSCs-MT. Transcriptomics revealed that ADSCs-MT showed significantly lower expression levels of ECM degradation, osteogenesis, and fibrocartilage markers. Finally, the protective effect of microtissues on inflammatory chondrocytes was validated. Overall, the ADSCs-MT constructed in this study achieved excellent cartilage regeneration and could be promising for the autologous application of cartilage microtissues.

Rotating cell culture system-induced injectable self-assembled microtissues with epidermal stem cells for full-thickness skin repair.

Epidermal stem cells (EpSCs) are crucial for wound healing and tissue regeneration, and traditional culture methods often lead to their inactivation. It is urgent to increase the yield of high quality EpSCs. In this study, primary EpSCs were isolated and cultured in a serum-free, feeder-free culture system. EpSCs are then expanded in a dynamic 3D environment using a rotating cell culture system (RCCS) with biodegradable porous microcarriers (MC). Over a period of 14 days, the cells self-assembled into microtissues with superior cell proliferation compared to 3D static culture. Immunofluorescence and qPCR analyses consistently showed that the stemness of the 3D microtissues was preserved, especially the COL17A1 associated with anti-aging was highly expressed in RCCS induced microtissues. In vivo experiments demonstrated that the group treated with 3D microtissues loaded with EpSCs showed enhanced early wound healing, and the injectable 3D microtissues were more conducive to maintaining cell viability and differentiation potential. Our study provides valuable insights into the dynamic 3D culture of EpSCs and introduces an injectable therapy using 3D microtissues loaded with EpSCs, which provides a new and effective approach for cell delivery and offering a promising strategy for guiding the regeneration of full-thickness skin defects.

Development of a cardiotoxicity evaluation system using a Heart-on-a-Chip Microdevice with aligned fiber device

Abstract Background and Purpose Cardiovascular cells differentiated from human induced pluripotent stem (iPS) cells, such as cardiomyocytes, are expected to be useful for evaluating cardiac pharmacology and toxicity in humans. In recent years, myocardial damage caused by anticancer drugs has begun to attract attention. Being able to evaluate human cardiotoxicity early in the development of novel drugs like anticancer agents confers advantages in terms of cost and development speed. The aim of this study was to develop a highly sensitive bioassay system that can evaluate the physiological function of the human heart, and to validate the efficacy of the system toward detection of cardiotoxicity of drugs. Methods We differentiated human iPS cells into cardiovascular cells (cardiomyocytes, endothelial cells and mural cells) and applied dynamic culture training to generate vascularized microtissues (VCM) with vascular network structures. By integrating this VCM with a microfluidic chip containing microchannels, we developed a heart-on-a-chip microdevice (HMD) specialized for evaluating cardiac function (Figure 1). Furthermore, through a collaborative study with the Stem Cell & Device Laboratory (SCAD), application of their aligned fiber device improved throughput and stability, allowing development of a SCAD-HMD capable of evaluating longer-term cardiotoxicity. Results SCAD-HMD can quantify physiological parameters of VCM such as ejection volume and force based on displacement of particles within the microchannels. Our results showed that SCAD-HMD not only exhibited pharmacological responses to representative circulatory stimulants, but also reproduced clinical events occurring in actual practice, demonstrating that the anticancer drug trastuzumab, commonly used for breast cancer treatment, causes myocardial disfunction when combined with doxorubicin. Conclusions This study demonstrated that SCAD-HMD can stably evaluate the toxicity of drugs on the human heart. In the future, establishing SCAD-HMD using iPS cells derived from individual patients and assessing responses to specific drugs may enable "individualized cardiotoxicity assessment systems" that can preemptively avoid cardiac complications associated with anticancer drugs and other pharmacological agents.

Hydroxyapatite/Silk Fibroin Composite Scaffold with a Porous Structure and Mechanical Strength Similar to Cancellous Bone by Electric Field-Induced Gel Technology.

Repair and regeneration of bone tissue defects is a multidimensional process that has been highly challenging to date. The artificial bone scaffold materials, which play a core role, still face the conflict that a biofriendly porous structure will reduce the mechanical performance and accelerate degradation. Herein, a multistage porous structured hydroxyapatite (HA)/silk fibroin (SF) composite scaffold (e-HA/SF) was successfully constructed by cleverly utilizing electric field-induced gel technology. The results indicated that the prepared e-HA/SF scaffolds possess biomimetic hierarchical porous structures with a suitable porosity similar to that of cancellous bone. The HA nanocrystals were uniformly encapsulated in the three-dimensional space of the composite scaffold, thus endowing the e-HA/SF composite scaffolds with an enhanced mechanical performance. Notably, the maximum compression stress and Young's modulus of e-HA/SF-2 scaffolds can reach 24.66 ± 0.88 and 28.91 ± 3.19 MPa, respectively, which are equivalent to those of cancellous bone. Such mechanical performance enhancement was previously unattainable through conventional freeze-drying strategies. Moreover, the introduction of bioactive nano-HA can trigger the optimal cell response in both static and dynamic cell culture experiments in vitro. The e-HA/SF composite scaffold developed in this study can better balance the conflict between the porous structure and mechanical and degradation properties of porous scaffolds.

Dynamic culture of cerebral organoids using a pillar/perfusion plate for the assessment of developmental neurotoxicity

Despite the potential toxicity of commercial chemicals to the development of the nervous system (known as developmental neurotoxicity or DNT), conventionalin vitrocell models have primarily been employed for the assessment of acute neuronal toxicity. On the other hand, animal models used for the assessment of DNT are not physiologically relevant due to the heterogenic difference between humans and animals. In addition, animal models are low-throughput, time-consuming, expensive, and ethically questionable. Recently, human brain organoids have emerged as a promising alternative to assess the detrimental effects of chemicals on the developing brain. However, conventional organoid culture systems have several technical limitations including low throughput, lack of reproducibility, insufficient maturity of organoids, and the formation of the necrotic core due to limited diffusion of nutrients and oxygen. To address these issues and establish predictive DNT models, cerebral organoids were differentiated in a dynamic condition in a unique pillar/perfusion plate, which were exposed to test compounds to evaluate DNT potential. The pillar/perfusion plate facilitated uniform, dynamic culture of cerebral organoids with improved proliferation and maturity by rapid, bidirectional flow generated on a digital rocker. Day 9 cerebral organoids in the pillar/perfusion plate were exposed to ascorbic acid (DNT negative) and methylmercury (DNT positive) in a dynamic condition for 1 and 3 weeks, and changes in organoid morphology and neural gene expression were measured to determine DNT potential. As expected, ascorbic acid did not induce any changes in organoid morphology and neural gene expression. However, exposure of day 9 cerebral organoids to methylmercury resulted in significant changes in organoid morphology and neural gene expression. Interestingly, methylmercury did not induce adverse changes in cerebral organoids in a static condition, thus highlighting the importance of dynamic organoid culture in DNT assessment.

Making the match: How Chinese food‐movement organizations develop consumers in the alternative market

AbstractMany social movement organizations promote their agendas in market spaces. As such they need to attract consumers to their cause. This article used longitudinal qualitative data collected between 2018 and 2023 in Chinese alternative food markets to explore their consumer recruitment and ongoing efforts to match movement ideologies with consumers' values, particularly regarding what makes “good food.” I argue that an iterative, two‐way learning process between organizations and consumers helped facilitate good matching and establish a stable consumer base. Organizations educated consumers about the production process and producers' stories, aligning their missions with consumers' pursuit of safety and taste and distinguishing them from mainstream markets. Consumers resonated with this cultural work but required responsible producers and market organizers. Some organizations fostered self‐affirming discussions to redirect consumer demands, while others interacted with and learned from the dynamic culture within consumer groups to co‐create their new definition of good food. This mutual learning motivated organizers to adjust their visions of ideal consumers to align movement ideologies with consumers' desires, creating the right amount of differentiation in alternative markets. This paper advances the literature on social movement organizations' market activities by revealing the interactive learning process and the diversity of alignment strategies.

Operationalizing critical success factors of employee ownership using principles of learning management

ABSTRACT The importance of employee-owned (EO) organizations around the world is increasing. Countries, communities and organizations are realizing that passing profits to workers increases wealth at all levels of society. The benefits, widely known, include personal prosperity, organizational profitability and stability, and a host of economic benefits for communities in which EO companies operate. Selling a company to employees, or starting a cooperative organization containing worker owners, is not without risk. New skills are required for the company to reap the rewards inherent in EO organizations, but the method of creating this change varies significantly from one organization to another. Each is unique, but there are some factors that are common to most EO organizations that have achieved a dynamic organizational culture. These factors, which are critical for success, can be isolated using structured research, organized through a lens of general systems theory and operationalized using principles of Learning Management (LM). The result is an organized knowledge transfer plan that maximizes resources and provides the highest probability of a successful transition to a uniquely profitable EO company.

Dynamically cultured, differentiated bovine adipose-derived stem cell spheroids as building blocks for biofabricating cultured fat

Cultured or cultivated meat, animal muscle, and fat tissue grown in vitro, could transform the global meat market, reducing animal suffering while using fewer resources than traditional meat production and no antimicrobials at all. To ensure the appeal of cultured meat to future customers, cultured fat is essential for achieving desired mouthfeel, taste, and texture, especially in beef. In this work we show the establishment of primary bovine adipose-derived stem cell spheroids in static and dynamic suspension culture. Spheroids are successfully differentiated using a single-step protocol. Differentiated spheroids from dynamic cultures maintain stability and viability during 3D bioprinting in edible gellan gum. Also, the fatty acid composition of differentiated spheroids is significantly different from control spheroids. The cells are cultured antibiotic-free to minimize the use of harmful substances. This work presents a stable and bioprintable building block for cultured fat with a high cell density in a 3D dynamic cell culture system.

Characterization of MSC Growth, Differentiation, and EV Production in CNF Hydrogels Under Static and Dynamic Cultures in Hypoxic and Normoxic Conditions.

Mesenchymal stem cells (MSCs) hold immense therapeutic potential due to their regenerative and immunomodulatory properties. However, to utilize this potential, it is crucial to optimize their in vitro cultivation conditions. Three-dimensional (3D) culture methods using cell-laden hydrogels aim to mimic the physiological microenvironment in vitro, thus preserving MSC biological functionalities. Cellulosic hydrogels are particularly promising due to their biocompatibility, sustainability, and tunability in terms of chemical, morphological, and mechanical properties. This study investigated the impact of (1) two physical crosslinking scenarios for hydrogels derived from anionic cellulose nanofibers (to-CNF) used to encapsulate adipose-derived MSCs (adMSCs) and (2) physiological culture conditions on the in vitro proliferation, differentiation, and extracellular vesicle (EV) production of these adMSCs. The results revealed that additional Ca2+-mediated crosslinking, intended to complement the self-assembly and gelation of aqueous to-CNF in the adMSC cultivation medium, adversely affected both the mechanical properties of the hydrogel spheres and the growth of the encapsulated cells. However, cultivation under dynamic and hypoxic conditions significantly improved the proliferation and differentiation of the encapsulated adMSCs. Furthermore, it was demonstrated that the adMSCs in the CNF hydrogel spheres exhibited potential for scalable EV production with potent immunosuppressive capacities in a bioreactor system. These findings underscore the importance of physiological culture conditions and the suitability of cellulosic materials for enhancing the therapeutic potential of MSCs. Overall, this study provides valuable insights for optimizing the in vitro cultivation of MSCs for various applications, including tissue engineering, drug testing, and EV-based therapies.

A single-cell 3D dynamic volume control system for chondrocytes.

In articular cartilage, zone-specific cellular morphology is a typical characteristic of cartilage tissue, which is related with chondrocyte function, inflammation and osteoarthritis (OA). Chondrocyte hypertrophic phenotype is a criticle physiological process which indicates a hallmark of chondrocyte terminal differentiation and bone formation. Thus, developing a in vitro cell culture system for dynamic regulation of single chondrocyte volume at a three-dimensional (3D) level is particularly necessary for understanding how physical cues of matrix microenvironment regulate chondrocyte fate and the degeneration of articular cartilage. Here, based on the soft lithography techniques, we have constructed well-defined single-cell 3D dynamic volume control system to recapitulate the physiological matrix microenvironment of single chondrocyte niche. The results of finite element analysis indicated that the stress and strain distribution in the cell culture region is homogeneous during the stretching process. Additionally, 3D dynamic volume expansion and compression of single cells in physiological or hyperphysiological can be realized in this cell culture system. Our device for single-cell 3D dynamic culture provides a microphysiological culture system for chondrocytes to explore the mechanisms of cartilage hypertrophy, as well as develops a new paradigm for functional cartilage tissue engineering and regenerative medicine.

Н.И. Воробьев и его роль в формировании академического татароведения в отечественной этнологии

The most important role in the formation of academic Tatar studies in domestic ethnology belongs to the outstanding scholar of the early-mid 20th century, Professor N.I. Vorobyev. With his works, he laid the foundations for a systematic approach to the study of the culture and life of the people, especially the reference group of the ethnic group – the Kazan Tatars. The use of data from related historical and geographical disciplines allowed him to pose and solve a number of important questions in the ethnic and ethnocultural history of the people. In his landmark monograph The Kazan Tatars (1953), special attention is given to their close root connection with the local Bulgarian civilisation – the ethnocultural prehistory of the people. The systematic approach consisted of the creation of N.I. Vorobyev’s first ethnocultural differentiation of the Volga-Ural Tatars, which was based on the cultural, everyday and linguistic differences within the ethnic group studied at that time. It was also manifested in the application of typological approaches to the classification of ethnographic material, which allowed him to present stable varieties of material culture (types) in dynamics, to outline analogues for them in other neighbouring and distant ethnic groups of Eurasia, and thereby to resolve a number of issues related to the cultural genesis of the people. The systematic approach was applied and improved in the research and scientific and organizational activities of his students and followers, including the authors of the volume “Historical and ethnographic atlas of the Tatar people”. Fundamental works of N.I. Vorobyev on the ethnography of the Volga-Ural Tatars laid the foundation for the formation of the Turkic-Tatar vector of academic ethnology in the Volga-Ural region of Russia. They are an invaluable resource for current and future generations of researchers.