Search Results (56)

Purpose: Collagen membranes with biomimetic mineralization are emerging as promising materials for bone regeneration, owing to their high biocompatibility. In this study, we developed a biogenic collagen membrane by combining citrate (C) pretreatment and carboxymethyl chitosan (CMC)-mediated mineralization and further evaluated its bone healing potential. Methods: C-CMC collagen membranes were prepared by lyophilization. The mineral composition and content were tested through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The micromorphology was observed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and scanning probe microscopy (SPM). Physical and mechanical properties, including the swelling rate, porosity, hydrophilicity, tensile strength, Young’s modulus, degradation, and barrier function, were also evaluated. Bone mesenchymal stem cells (BMSCs) were cultured in vitro to observe their behavior. An in vivo critical-size rat calvarial defect model was used to validate the effects of the membrane on bone regeneration. Results: The C-CMC collagen membrane was successfully synthesized as a collagen–hydroxyapatite complex with intrafibrillar mineralization, exhibiting improved mechanical properties and an optimal swelling rate, porosity, hydrophilicity, and degradation rate. Additionally, the C-CMC collagen membrane promoted BMSC proliferation, adhesion, and osteogenesis while preventing epithelial cell infiltration. In vivo experiments indicated that C-CMC collagen membranes significantly stimulated bone regeneration without causing systemic toxicity. Conclusions: Our findings suggest that the C-CMC collagen membrane possesses satisfactory physical and mechanical properties, along with good biocompatibility and efficacy in bone defect regeneration, making it a potential candidate for a bioactive guided bone regeneration membrane in clinical applications. Full article

The accurate measurement of CO₂ concentration in fermentation off-gas is crucial for monitoring and optimizing bioprocesses, particularly in mammalian cell cultures. In this study, we successfully utilized Raman off-gas spectroscopy to achieve time-resolved prediction of CO₂ concentrations in the fermentation off-gas. Our experiments were conducted using two different media: a commercial medium (medium 1) and an in-house Roche medium (medium 2), each tested with two different lots. The results demonstrated that Raman spectroscopy provides precise and real-time CO₂ measurements, which are essential for effective process monitoring and control. Furthermore, we established that CO₂ off-gas analysis can be directly correlated with the pH value of the fermentation medium. This correlation allows for accurate pH prediction with comparable precision to traditional methods, where CO₂ levels are first determined via Raman spectroscopy or an off-gas analyzer and then used to infer pH through a correlation curve. In the final step of our study, we employed a Raman submers probe to predict CO₂ and pH directly within the fermentation medium. Compared to the model accuracy in the off-gas stream, the performance of the Raman submers probe in predicting CO₂ and pH within the medium was significantly worse, likely due to the absence of a pretrained model for CO₂. Our findings highlight the potential of Raman off-gas spectroscopy as a powerful tool for real-time bioprocess monitoring and control, offering significant advantages in terms of accuracy and efficiency. Full article

In cytogenetics, the ability to perform FISH (Fluorescence In Situ Hybridization) experiments using probes that map very closely together depends on the capacity to produce sufficiently long chromosomes. Traditionally, colcemid is the chemical agent used to obtain metaphase spreads. However, various substances have been reported to arrest cells in an earlier stage of mitosis than the metaphase, potentially providing longer chromosomes. In this study, we tested seven substances different from colcemid, which, according to the literature, have this capability: Vinblastine, Combretastatin A-4, Podophyllotoxin, Org9935, Nocodazole, Paclitaxel, and Griseofulvin. All substances were tested on lymphocyte cultures derived from whole blood at the same concentration: 0.1 µg/mL. Among these, Org9935 and Griseofulvin were confirmed to have the ability to produce metaphases with longer chromosomes compared to those obtained with colcemid. Full article

Non-EU international students encounter considerable challenges in social integration, cultural adaptation, and emotional well-being within UK higher education. Despite this, the role of internet memes as a form of participatory digital media in mediating these experiences has not been extensively studied. This paper examines how non-EU students at a British university utilise memes to manage cross-cultural identity and daily stressors. Employing an Experience-Centred Design (ECD) approach, our qualitative research involved 20 participants through digital cultural probes, semi-structured interviews, and co-design workshop. We discovered that memes serve a dual role: they provide emotional bridges that foster a sense of belonging through shared humour, yet they also risk exclusion due to cultural opacity. We introduce the concept of “negotiated humour”, which requires cross-cultural explanation and reduces comedic spontaneity but enhances intercultural understanding. Furthermore, we identify a continuum of meme usage that reflects different phases of acculturation, ranging from expressing frustrations to creating hybrid cultural expressions. This study contributes to cross-cultural adaptation theory by highlighting memes as boundary objects in identity negotiation. We suggest design implications for culturally sensitive platforms, such as contextual footnotes, and institutional interventions like meme-based orientation activities to exploit humour’s potential for fostering inclusive dialogue. Our research highlights how transient digital humour can provide deep insights into identity, community, and the complex dynamics of cross-cultural adaptation. Full article

Background: Community gardens are increasingly popular in Canadian cities, serving as transformative spaces where immigrants can develop self-reliant strategies for accessing culturally familiar and healthy nutritious foods. However, numerous facilitators and barriers exist that limit the engagement of racialized groups such as Black-identifying immigrants. Using a socio-ecological framework, this research explores barriers and facilitators of engagement of Black African immigrants in collective community gardening in Alberta, Canada. Methods: The study adopted a community-based participatory research (CBPR) approach using mixed methods. Data collection included structured surveys (n = 119) to assess general engagement, facilitators, and barriers; in-depth interviews (n = 10) to explore lived experiences; and Afrocentric sharing circles (n = 2) to probe collective perspectives in relation to engagement in collective gardening. Participants were purposefully recruited through community networks within African immigrant-serving community organizations. Results: Our findings revealed how barriers at various levels of the socio-ecological model (SEM) interact to shape the interest and engagement of African immigrants in collective community gardening. Access to collective gardens was associated with significant benefits, including maintaining healthy foodways, knowledge exchange, growing social capital, and community connections that support overall wellbeing. Conclusions: This study contributes an accessible framework for understanding and addressing the complex barriers that limit engagement in community gardens for vulnerable communities, while highlighting opportunities for creating more inclusive and culturally responsive urban agriculture initiatives. Full article

The prediction of the cell yield in large-scale bioreactor culture is an important factor for various cell therapy bioprocess operations to ensure consistency in cell quality and efficient use of resources. However, the shear sensitivity of cells used in cell therapy manufacturing can make such predictions difficult, particularly in large-scale suspension cultures that have significant stresses without representative scale down models. The PBS Vertical-Wheel (VW) bioreactors have been demonstrated to provide a homogeneous hydrodynamic environment with low shear for cell culture at various scales (0.1–80 L) and is thereby employed for various shear-sensitive cells. In this study, the oxygen transfer rate for surface aeration for three large-scale VW bioreactors was measured along with the specific oxygen uptake rate (sOUR) of iPSCs cultured in the bioreactors. The oxygen mass transfer coefficient was measured in PBS-3/15/80 L bioreactors at different agitation rates, headspace gas flowrates, and working volumes using the static gassing-out method. The sOUR of iPSCs was measured using the dynamic method in the PBS-0.1 L Mini with a custom DO probe configuration. The results from both experiments were combined to calculate the theoretical maximum cell density before oxygen limitation across VW bioreactors at 2 L/3 L/10 L/15 L/50 L/80 L working volumes at a different agitation speed and aeration rate. Full article

Grana Padano (GP) is an Italian hard cooked cheese characterized by a long ripening process and high protein and Ca contents. After in vitro static simulated gastrointestinal digestion, GP digest contained caseinophosphopeptides that were 6 to 24 amino acids in length, including tri-phosphorylated species incorporating the pSer-pSer-pSer-Glu-Glu cluster. Using rat ileum tissue, the digest was used to assess Ca absorption ex vivo, which showed significantly better results for the GP digest in comparison to the CaCO₃ aqueous solution. An in vitro intestinal model based on Caco-2/HT-29 cell co-culture was able to mimic Ca absorption from GP digest, with Ca-rich water as a control. The metabolite-containing medium was then used to treat osteoblast-like SaOS-2 cells. As a consequence, metabolized GP digest significantly increased the number of osteoblasts, whereas the metabolized water did not exert this effect. Finally, the mice were fed diets containing GP or CaCO₃ and pea isolate and the in vivo outcomes were assessed through fluorescent probe and computed tomography. Mice fed a diet containing GP showed a higher increase in bone remodeling and volume in comparison to those fed a control diet containing CaCO₃ and pea isolate. Overall, the ex vivo, in vitro and in vivo experiments highlighted the effectiveness of GP in improving Ca absorption, osteoblast proliferation and bone remodeling and volume. Full article

Background/Objectives: Aromatase plays a crucial role in the conversion of androgens to oestrogens and is often overexpressed in hormone-dependent tumours, particularly breast cancer. [18F]BIBD-071, which has excellent binding affinity for aromatase and good pharmacokinetics, has potential for the diagnosis and treatment of aromatase-related diseases. The MCF-7 cell line, which is hormone receptor-positive (HR+), was used in the assessment of the novel [18F]-labelled radiotracer [18F]BIBD-071 via positron emission tomography (PET) imaging of an HR+ breast cancer xenograft model. Methods: [18F]BIBD-071 was synthesised, radiolabelled, and then subjected to in vitro stability testing. MCF-7 cells were cultured and implanted into BALB/c nude mice to establish subcutaneous tumour models. MicroPET/CT imaging was conducted after injection of the tracer at 1 and 2 h, and a blocking study was also conducted using the aromatase inhibitor letrozole. A block experiment was used to prove the specificity of the probe. Biodistribution studies were performed at 0.5, 1, and 2 h post injection (p.i.). Immunofluorescence was used to assess aromatase expression in MCF-7 cells. Results: [18F]BIBD-071 showed excellent in vitro stability and specific uptake in an MCF-7 xenograft tumour model. MicroPET/CT imaging at 1 and 2 h p.i. revealed excellent tumour visualisation with a favourable tumour-to-background ratio. Biodistribution data revealed high tracer uptake in the liver, small intestine, and stomach, with significant washout from the bloodstream and tumour over time. The tumour uptakes at 0.5 h, 1 h, and 2 h were 3.84 ± 0.13, 2.5 ± 0.17, and 2.54 ± 0.32, respectively. The tumour uptake significantly decreased between 0.5 h and 1 h (p < 0.0001), whereas there was no significant difference between 1 and 2 h. The tumour/background ratios at 0.5 h, 1 h, and 2 h were 1.19 ± 0.03, 1.12 ± 0.17, and 1.42 ± 0.11, respectively. Immunofluorescence confirmed robust aromatase expression in MCF-7 cells, which was correlated with [18F]BIBD-071 tumour uptake. Conclusions: [18F]BIBD-071 is a promising PET tracer for diagnosing and monitoring HR+ breast cancer, warranting further research into hormone-dependent cancers. Full article

Building on our previous work presented at the Eurographics GCH conference, this paper further explores the characteristics of an “authentic experience”, developing a framework that can be applied to the development of XR and hybrid applications in the field of cultural heritage. While recognising the broader concept of authenticity, we have not focused on an in-depth analysis of it. Instead, we focus specifically on “authentic experiences”. Here, we have extended the definition of authenticity beyond realism or sense of presence, proposing instead a multi-dimensional approach to engaging users cognitively, emotionally, and sensorially (the “Self” dimension) and, at the same time, including two other fundamental dimensions (the “Others” and the “World”) intrinsically connected to the “Self”. We have then further detailed these three dimensions, which are the pillars of the perception of authenticity, identifying their “components” and “elements”. Finally, we transformed the elements into “actionable” design indications, setting the ground to further develop specific design (UI and UX) strategies for digital heritage and serious game applications. Full article

A gallium nitride (GaN) semiconductor is one of the most promising materials integrated into biomedical devices to play the roles of connecting, monitoring, and manipulating the activity of biological components, due to its excellent photoelectric properties, chemical stability, and biocompatibility. In this work, it was found that the photogenerated free charge carriers of the GaN substrate, as an exogenous stimulus, served to promote neural stem cells (NSCs) to differentiate into neurons. This was observed through the systematic investigation of the effect of the persistent photoconductivity (PPC) of GaN on the differentiation of primary NSCs from the embryonic rat cerebral cortex. NSCs were directly cultured on the GaN surface with and without ultraviolet (UV) irradiation, with a control sample consisting of tissue culture polystyrene (TCPS) in the presence of fetal bovine serum (FBS) medium. Through optical microscopy, the morphology showed a greater number of neurons with the branching structures of axons and dendrites on GaN with UV irradiation. The immunocytochemical results demonstrated that GaN with UV irradiation could promote the NSCs to differentiate into neurons. Western blot analysis showed that GaN with UV irradiation significantly upregulated the expression of two neuron-related markers, βIII-tubulin (Tuj-1) and microtubule-associated protein 2 (MAP-2), suggesting that neurite formation and the proliferation of NSCs during differentiation were enhanced by GaN with UV irradiation. Finally, the results of the Kelvin probe force microscope (KPFM) experiments showed that the NSCs cultured on GaN with UV irradiation displayed about 50 mV higher potential than those cultured on GaN without irradiation. The increase in cell membrane potential may have been due to the larger number of photogenerated free charges on the GaN surface with UV irradiation. These results could benefit topical research and the application of GaN as a biomedical material integrated into neural interface systems or other bioelectronic devices. Full article

Online Virtual Museums (OVM) serve as vital conduits for the global propagation of cultural heritage but grapple with the challenge of user disorientation due to the absence of physical references. Leveraging the successful paradigm of game-based virtual navigation, this study investigates the potential integration of game mini-map navigation design elements into OVM to enhance spatial cognition. Through empirical investigation, a conceptual model was developed to probe the role of core mini-map design elements (interactivity, visual guidance, and information content) in augmenting spatial cognition. Results indicate that optimizing these elements significantly enhances user immersion and presence, thereby improving spatial cognition. Specifically, information content and visual guidance exerted stronger effects on immersion and presence, respectively. This research contributes a novel perspective on incorporating game design strategies into non-game virtual experiences, offering practical guidance for enhancing navigation in OVM and similar virtual environments. This bridges the gap between virtual museum navigation and game design, propelling the evolution of more dynamic, interactive, and user-centric virtual environments, thus fostering the preservation and dissemination of digital cultural heritage. Full article

The few commercially available chemosensors and published probes for in vitro Zn²⁺ detection in two-photon microscopy are compromised by their flawed spectroscopic properties, causing issues in selectivity or challenging multistep syntheses. Herein, we present the development of an effective small molecular GFP chromophore-based fluorescent chemosensor with a 2,2′-bipyridine chelator moiety (GFZnP BIPY) for Zn²⁺ detection that has straightforward synthesis and uncompromised properties. Detailed experimental characterizations of the free and the zinc-bound compounds within the physiologically relevant pH range are presented. Excellent photophysical characteristics are reported, including a 53-fold fluorescence enhancement with excitation and emission maxima at 422 nm and 492 nm, respectively. A high two-photon cross section of 3.0 GM at 840 nm as well as excellent metal ion selectivity are reported. In vitro experiments on HEK 293 cell culture were carried out using two-photon microscopy to demonstrate the applicability of the novel sensor for zinc bioimaging. Full article

Kemerovo virus (KEMV) is a tick-borne orbivirus transmitted by ticks of the genus Ixodes. Previous animal experimentation studies with orbiviruses, in particular the interferon receptor double knock-out (IFNAR^(−/−)) mouse model, did not indicate bias that is related to age or sex. We endeavoured to assess the effect of serial and alternated passages of KEMV in mammalian or Ixodes cells on virus replication and potential virulence in male or female IFNAR^(−/−) mice, with important age differences: younger males (4–5 months old), older males (14–15 months old), and old females (14–15 months old). After 30 serial passages in mammalian or tick cells, or alternated passages in the two cell types, older female mice which were inoculated with the resulting virus strains were the first to show clinical signs and die. Younger males behaved differently from older males whether they were inoculated with the parental strain of KEMV or with any of the cell culture-passaged strains. The groups of male and female mice inoculated with the mammalian cell culture-adapted KEMV showed the lowest viraemia. While older female and younger male mice died by day 6 post-inoculation, surprisingly, the older males survived until the end of the experiment, which lasted 10 days. RNA extracted from blood and organs of the various mice was tested by probe-based KEMV real-time RT-PCR. Ct values of the RNA extracts were comparable between older females and younger males, while the values for older males were >5 Ct units higher for the various organs, indicating lower levels of replication. It is noteworthy that the hearts of the old males were the only organs that were negative for KEMV RNA. These results suggest, for the first time, an intriguing age- and sex-related bias for an orbivirus in this animal model. Changes in the amino acid sequence of the RNA-dependent RNA polymerase of Kemerovo virus, derived from the first serial passage in Ixodes cells (KEMV Ps.IRE1), were identified in the vicinity of the active polymerase site. This finding suggests that selection of a subpopulation of KEMV with better replication fitness in tick cells occurred. Full article

Although the enormous potential of droplet-based microfluidics has been successfully demonstrated in the past two decades for medical, pharmaceutical, and academic applications, its inherent potential has not been fully exploited until now. Nevertheless, the cultivation of biological cells and 3D cell structures like spheroids and organoids, located in serially arranged droplets in micro-channels, has a range of benefits compared to established cultivation techniques based on, e.g., microplates and microchips. To exploit the enormous potential of the droplet-based cell cultivation technique, a number of basic functions have to be fulfilled. In this paper, we describe microfluidic modules to realize the following basic functions with high precision: (i) droplet generation, (ii) mixing of cell suspensions and cell culture media in the droplets, (iii) droplet content detection, and (iv) active fluid injection into serially arranged droplets. The robustness of the functionality of the Two-Fluid Probe is further investigated regarding its droplet generation using different flow rates. Advantages and disadvantages in comparison to chip-based solutions are discussed. New chip-based modules like the gradient, the piezo valve-based conditioning, the analysis, and the microscopy module are characterized in detail and their high-precision functionalities are demonstrated. These microfluidic modules are micro-machined, and as the surfaces of their micro-channels are plasma-treated, we are able to perform cell cultivation experiments using any kind of cell culture media, but without needing to use surfactants. This is even more considerable when droplets are used to investigate cell cultures like stem cells or cancer cells as cell suspensions, as 3D cell structures, or as tissue fragments over days or even weeks for versatile applications. Full article

Quercetin forms complexes with various metals due to its structural attributes. It predominantly exhibits chelating activity at the 3-hydroxy/4-carbonyl group. Previously, coordination in synthetically obtained quercetin–zinc (II) complexes has been limited to this group. However, the expanded coordination observed in quercetin–iron complexes has opened avenues for diverse applications. Thus, synthesizing novel quercetin–zinc complexes with different coordination positions is a significant advance. In our study, we not only synthesized and comprehensively characterized a new quercetin–zinc (II) complex, Zn-Q, but also evaluated the structure and bioactivity of chelate complexes (Q+Zn) derived from co-treatment in cell culture mediums. The structure of the new compound Zn-Q was comprehensively characterized using 1D ¹H and 2D correlation spectroscopy (COSY), nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV-Vis), electrospray ionization mass spectrometer (ESI-MS), and X-ray diffraction analysis (XRD) analysis. Subcellular localization and absorption of these zinc (II) complexes were determined using the ZnAF-2 DA zinc ion fluorescence probe. Throughout the experiments, both Zn-Q and Q+Zn exhibited significant antioxidant, cell growth inhibitory, and anticancer effects in HepG2 and HCT116 cells, with Zn-Q showing the highest potential for inducing apoptosis via the caspase pathway. Tracking intracellular zinc complex absorption using zinc fluorescent probes revealed zinc (II) localization around the cell nucleus. Interestingly, there was a proportional increase in intracellular quercetin absorption in conjunction with zinc (II) uptake. Our research highlights the advantages of quercetin complexation with zinc (II): enhanced anticancer efficacy compared to the parent compound and improved bioavailability of both quercetin and zinc (II). Notably, our findings, which include enhanced intracellular uptake of both quercetin and zinc (II) upon complex formation and its implications in apoptosis, contribute significantly to the understanding of metal–polyphenol complexes. Moving forward, comprehensive functional assessments and insights into its mechanism of action, supported by animal studies, are anticipated. Full article