The oral mucosa functions as a physico-chemical and immune barrier to external stimuli, and an adequate width of the keratinized mucosa around the teeth or implants is crucial to maintaining them in a healthy and stable condition. In this study, for the first time, bulk RNA-seq analysis was performed to explore the gene expression of laser microdissected epithelium and lamina propria from mice, aiming to investigate the differences between keratinized and non-keratinized oral mucosa. Based on the differentially expressed genes (DEGs) and Gene Ontology (GO) Enrichment Analysis, bone morphogenetic protein 2 (BMP-2) was identified to be a potential regulator of oral mucosal keratinization. Monoculture and epithelial–mesenchymal cell co-culture models in the air–liquid interface (ALI) indicated that BMP-2 has direct and positive effects on epithelial keratinization and proliferation. We further performed bulk RNA-seq of the ALI monoculture stimulated with BMP-2 in an attempt to identify the downstream factors promoting epithelial keratinization and proliferation. Analysis of the DEGs identified, among others, IGF2, ID1, LTBP1, LOX, SERPINE1, IL24, and MMP1 as key factors. In summary, these results revealed the involvement of a well-known growth factor responsible for bone development, BMP-2, in the mechanism of oral mucosal keratinization and proliferation, and pointed out the possible downstream genes involved in this mechanism. Full article

As blockchain becomes more widely used, a growing number of application fields are becoming interested in blockchain to benefit from its decentralised nature, invariability, security, transparency, quick transaction capabilities, and cost-effectiveness. Blockchain has a wide range of applications and uses in healthcare. Distributed ledger technology facilitates the secure transfer of patient medical records, manages the medicine supply chain, and creates an efficient, transparent, safe, and effective way of communicating data across global healthcare. The organ transplantation process (OTP) is one of the healthcare areas that benefit from the use of such technology to make its process more secure and transparent. In this article, we put forward a systematic literature review analysis on the application of blockchain to the OTP. Additionally, we address and highlight the barriers and challenges that arise while using blockchain technology for the OTP. We also offer some suggestions for future developments that would enhance blockchain’s implementation in the OTP domain. Full article

Although evidence-based nutrition care is recommended for patients with cancer, current nutrition care practices provided by nutritionists and dietitians in Southeast Asian countries are not clearly reported. The aim of this scoping review was to describe nutritionists’ and dietitians’ current oncology nutrition care practice within Southeast Asia by identifying access to dietetic services, tools or strategies used in providing care, and barriers and enablers to implementing nutrition care practices. Five databases (Ovid MEDLINE, Global Health, Embase, Cochrane Central Register of Controlled Trials, and Proquest) were searched through structured search strategies, in addition to strategic searching of grey literature. A total of 4261 sources of evidence were retrieved. After full-text screening, 18 studies from Southeast Asian countries met the inclusion criteria and were included in this review. The provision and reporting of nutrition care practices provided by nutritionists and dietitians were limited. Access to dietetic services, including nutritional screening tools and reason to be referred, were varied within studies. Barriers and enablers to nutrition care provision were unique and related to each country’s specific resources and guidelines. In summary, there was varied reporting of nutrition care practices provided to patients with cancer in Southeast Asia and a lack of clarity on the actual standardized processes. Future research is warranted to further explore the barriers and enablers to providing nutrition care by local nutritionists and dietitians in Southeast Asia. Full article

Image quality assessment of magnetic resonance imaging (MRI) data is an important factor not only for conventional diagnosis and protocol optimization but also for fairness, trustworthiness, and robustness of artificial intelligence (AI) applications, especially on large heterogeneous datasets. Information on image quality in multi-centric studies is important to complement the contribution profile from each data node along with quantity information, especially when large variability is expected, and certain acceptance criteria apply. The main goal of this work was to present a tool enabling users to assess image quality based on both subjective criteria as well as objective image quality metrics used to support the decision on image quality based on evidence. The evaluation can be performed on both conventional and dynamic MRI acquisition protocols, while the latter is also checked longitudinally across dynamic series. The assessment provides an overall image quality score and information on the types of artifacts and degrading factors as well as a number of objective metrics for automated evaluation across series (BRISQUE score, Total Variation, PSNR, SSIM, FSIM, MS-SSIM). Moreover, the user can define specific regions of interest (ROIs) to calculate the regional signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), thus individualizing the quality output to specific use cases, such as tissue-specific contrast or regional noise quantification. Full article

The FitzHugh–Nagumo model has been used empirically to model certain types of neuronal activities. It is also a non-linear dynamical system applicable to chemical kinetics, population dynamics, epidemiology and pattern formation. In the literature, many approaches have been proposed to study its dynamics. In this paper, initially, we have employed cutting-edge tools from discrete dynamics for discretization and fixed points. It has been proven that an exact discrete scheme exists for this paradigm. This project also considers the phase space and integral surfaces of these evolutionary equations. In addition, it carries out a thorough symmetry analysis of this reaction diffusion system to find equivalent systems. Moreover, steady-state solutions are obtained using ansatzes for traveling wave solutions. The existence of infinite traveling wave solutions has also been proven. Yet again, this investigation establishes the potential of symmetry methods to unravel non-linearity. Finally, singular perturbation theory has been employed to obtain analytical approximations and to study stability in different parameter regimes. Full article

The influence of bovine serum albumin (BSA) on collapsing poly(N-isopropylacrylamide) (PNIPAM) chains was studied with turbidimetry and spin probe and spin label electron paramagnetic resonance spectroscopy. An increased ratio of collapsed chains in aqueous solutions in the narrow temperature region near the LCST appeared in the presence of 2.5–10 wt% BSA. The spin probe EPR data indicate that the inner cavities of the BSA dimers are probably responsive to the capture of small hydrophobic or amphiphilic molecules, such as TEMPO nitroxyl radical. The observed features of the structure and dynamics of inhomogeneities of aqueous PNIPAM-BSA solutions, including their mutual influence on the behavior of the polymer and protein below the LCST, should be considered when developing and investigating PNIPAM-based drug delivery systems. Full article

Heart failure (HF) presents a significant global health challenge recognised by frequent hospitalisation and high mortality rates. The assessment of left ventricular (LV) ejection fraction (EF) plays a crucial role in diagnosing and predicting outcomes in HF, leading to its classification into preserved (HFpEF), reduced (HFrEF), and mildly reduced (HFmrEF) EF. HFmrEF shares features of both HFrEF and HFpEF but also exhibits distinct characteristics. Despite advancements, managing HFmrEF remains challenging due to its diverse presentation. Large-scale studies are needed to identify the predictors of clinical outcomes and treatment responses. Utilising biomarkers for phenotyping holds the potential for discovering new treatment targets. Given the uncertainty surrounding optimal management, individualised approaches are imperative for HFmrEF patients. This chapter examines HFmrEF, discusses the rationale for its re-classification, and elucidates HFmrEF’s key attributes. Furthermore, it provides a comprehensive review of current treatment strategies for HFmrEF patients. Full article

Research on retinoid-based cancer prevention, spurred by the effects of vitamin A deficiency on gastric cancer and subsequent clinical studies on digestive tract cancer, unveils novel avenues for chemoprevention. Acyclic retinoids like 4,5-didehydrogeranylgeranoic acid (4,5-didehydroGGA) have emerged as potent agents against hepatocellular carcinoma (HCC), distinct from natural retinoids such as all-trans retinoic acid (ATRA). Mechanistic studies reveal GGA’s unique induction of pyroptosis, a rapid cell death pathway, in HCC cells. GGA triggers mitochondrial superoxide hyperproduction and ER stress responses through Toll-like receptor 4 (TLR4) signaling and modulates autophagy, ultimately activating pyroptotic cell death in HCC cells. Unlike ATRA-induced apoptosis, GGA and palmitic acid (PA) induce pyroptosis, underscoring their distinct mechanisms. While all three fatty acids evoke mitochondrial dysfunction and ER stress responses, GGA and PA inhibit autophagy, leading to incomplete autophagic responses and pyroptosis, whereas ATRA promotes autophagic flux. In vivo experiments demonstrate GGA’s potential as an anti-oncometabolite, inducing cell death selectively in tumor cells and thus suppressing liver cancer development. This review provides a comprehensive overview of the molecular mechanisms underlying GGA’s anti-HCC effects and underscores its promising role in cancer prevention, highlighting its importance in HCC prevention. Full article

This paper concentrates on the general birth–death processes with two different types of catastrophes. The Laplace transform of transition probability function for birth–death processes with two-type catastrophes is successfully expressed with the Laplace transform of transition probability function of the birth–death processes without catastrophe. The first effective catastrophe occurrence time is considered. The Laplace transform of its probability density function, expectation and variance are obtained. Full article

Lammers and Stapel reported that high power increases deontological (rule-based) moral thinking, and low power increases utilitarian (outcome-based) moral thinking. However, the dilemmas were mild and did not involve harm to life. Here, we examined whether the presence or absence of harm to life affects the moral decisions of powerholders. To help establish the replicability and validity of the effects of power on moral judgments in the absence of harm to life, we first performed an exact replication of a study conducted by Lammers and Stapel, and this experiment was followed up by a similar study in an organizational context in China (Studies 1 and 2). Studies 3 and 4 investigated whether power and the presence/absence of harm to life interacted with preferences for deontological versus utilitarian moral judgments. Power consistently triggered deontological thinking. However, power differences in moral reasoning only emerged when there was no harm to life. Harm prompted deontological responses among control and powerless individuals, which nullified differences across the power conditions. The findings demarcate the generalizability of the association between power and a moral thinking style. Full article

(1) Background: Non-small-cell lung cancer (NSCLC) represents a significant global health challenge, contributing to numerous cancer deaths. Despite advances in diagnostics and therapy, identifying reliable biomarkers for prognosis and therapeutic stratification remains difficult. Toll-like receptors (TLRs), crucial for innate immunity, now show potential as contributors to cancer development and progression. This study aims to investigate the role of TLR expression as potential biomarkers in the development and progression of NSCLC. (2) Materials and Methods: The study was conducted on 89 patients diagnosed with NSCLC and 40 healthy volunteers, for whom the prevalence of TLR2, TLR3, TLR4, TLR7, TLR8, and TLR9 was assessed on selected subpopulations of T and B lymphocytes in the peripheral blood of recruited patients along with the assessment of their serum concentration. (3) Result: Our study showed several significant changes in NSCLC patients at the beginning of the study. This resulted in a 5-year follow-up of changes in selected TLRs in recruited patients. Due to the high mortality rate of NSCLC patients, only 16 patients survived the 5 years. (4) Conclusions: The results suggest that TLRs may constitute real biomarker molecules that may be used for future prognostic purposes in NSCLC. However, further validation through prospective clinical and functional studies is necessary to confirm their clinical utility. These conclusions may lead to better risk stratification and tailored interventions, benefiting NSCLC patients and bringing medicine closer to precision. Full article

This study explores an approach to design and prepare a multilayer scaffold mimicking interstratified natural tissue. This multilayer construct, composed of chitosan matrices with graded nanohydroxyapatite concentrations, was achieved through an in situ biomineralization process applied to individual layers. Three distinct precursor concentrations were considered, resulting in 10, 20, and 30 wt% nanohydroxyapatite content in each layer. The resulting chitosan/nanohydroxyapatite (Cs/n-HAp) scaffolds, created via freeze-drying, exhibited nanohydroxyapatite nucleation, homogeneous distribution, improved mechanical properties, and good cytocompatibility. The cytocompatibility analysis revealed that the Cs/n-HAp layers presented cell proliferation similar to the control in pure Cs for the samples with 10% n-HAp, indicating good cytocompatibility at this concentration, while no induction of apoptotic death pathways was demonstrated up to a 20 wt% n-Hap concentration. Successful multilayer assembly of Cs and Cs/n-HAp layers highlighted that the proposed approach represents a promising strategy for mimicking multifaceted tissues, such as osteochondral ones. Full article

Aubergine (Solanum melongena L.) (Solanaceae) is a widespread crop in the Mediterranean basin. Verticillium dahliae is one of the main soil-borne pathogens affecting the aubergine crop. Its control has traditionally been achieved by soil fumigation with chemical disinfectants. Restrictions on the use of chemical fumigants have led to the search for solutions in genetic resistance using rootstocks. In southeastern Spain, aubergines are grafted for the control of V. dahliae. Two Solanum torvum rootstocks (Hugo F1 and Torpedo) and a Solanum melongena hybrid (Javah F1) were tested against five isolates of V. dahliae obtained from grafted (A1 and A2) and ungrafted (Vd8, Vd17 and Vd66) aubergines compared with the susceptible cultivar Larne F1 under controlled conditions. Isolates from grafted plants infected all three rootstocks, with differences observed in the percentage of plants with symptoms and in the disease symptom severity. Three strains isolated from the ungrafted aubergines (Vd8, Vd17 and Vd66) infected Javah F1 rootstock. The Hugo F1 and Torpedo rootstocks showed a high level of resistance to V. dahliae, while Javah F1 was susceptible to the pathogen. The Hugo F1 and Torpedo rootstocks are suitable for mitigating the effects of Verticillium wilt in Mediterranean aubergine crops. Understanding the nature of the resistance from S. torvum could enhance the benefits of grafting or facilitate the introduction of resistance into commercial cultivars. Full article

Fish germ cell transplantation holds great potential for conserving endangered species, improving cultured fish breeds, and exploring reproductive techniques. However, low transplantation efficiency is a common issue in heterotransplantation. This study transplanted fat greenling (Hexagrammos otakii) spermatogonia into the testes of spotted sea bass (Lateolabrax maculatus) to investigate factors that might affect the colonization and fixation of heterologous transplanted germ cells. Results indicated that transplanted fat greenling spermatogonia cells were successfully detected in the early transplantation phase in spotted sea bass. Their numbers gradually decreased over time, and after 10 days post-transplantation, more than 90% of the transplanted cells underwent apoptosis. Transcriptome sequencing analysis of the testes of spotted sea bass and fat greenling spermatogonia on days 1 and 10 post-transplantation revealed that this apoptosis process involved many immune-related genes and their associated signaling pathways. Acute immune rejection marker genes prf1 and gzmb were detected in the spotted sea bass testes, while immune tolerance genes lck and zap-70 were expressed in the fat greenling spermatogonia. Additionally, differential expression of prf1 and gzmb genes was screened from spotted sea bass, with experimental evidence indicating that PRF1 and GZMB protein from spotted sea bass primarily induce apoptosis in transplanted fat greenling spermatogonia via the mitochondrial apoptosis pathway, at the protein level. This suggests that the difficulties in heterotransplantation are primarily related to acute immune rejection, with PRF1 and GZMB playing significant roles. Full article

Nitrides are the leading semiconductor material used for the fabrication of high electron mobility transistors (HEMTs). They exhibit piezoelectric properties, which, coupled with their high mechanical stiffness, expand their versatile applications into the fabrication of piezoelectric devices. Today, due to advances in device technology that result in a reduction in the size of individual transistor elements and due to increased structural complexity (e.g., multi-gate transistors), the integration of piezoelectric materials into HEMTs leads to an interesting occurrence, namely acoustic emission from the transistor gate due to piezoelectric effects. This could affect the device’s performance, reliability, and durability. However, this phenomenon has not yet been comprehensively described. This paper aims to examine this overlooked aspect of AlGaN/GaN HEMT operation, that is, the acoustic emission from the gate region of the device induced by piezoelectric effects. For this purpose, dedicated test structures were designed, consisting of two narrow 1.7 μm-wide metallization strips placed at distances ranging from 5 μm to 200 μm fabricated in AlGaN/GaN heterostructures to simulate and examine the gate behavior of the HEMT transistor. For comparison, the test device structures were also fabricated on sapphire, which is not a piezoelectric material. Measurements of acoustic and electrical interactions in the microwave range were carried out using the “on wafer” method with Picoprobe’s signal–ground–signal (SGS)-type microwave probes. The dependence of reflectance |S11| and transmittance |S21| vs. frequency was investigated, and the coupling capacitance was determined. An equivalent circuit model of the test structure was developed, and finite element method simulation was performed to study the distribution of the acoustic wave in the nitride layers and substrate for different frequencies using Comsol Multiphysics software. At frequencies up to 2–3 GHz, the formation of volume waves and a surface wave, capable of propagating over long distances (in the order of tens of micrometers) was observed. At higher frequencies, the resulting distribution of displacements as a result of numerous reflections and interferences was more complicated. However, there was always the possibility of a surface wave occurrence, even at large distances from the excitation source. At small gate distances, electrical interactions dominate. Above 100 µm, electrical interactions are comparable to acoustic ones. With further increases in distance, weakly attenuated surface waves will dominate. Full article

The objective of this study was to investigate gene regulation of the developing fetal brain from congenic or inbred mice strains that differed in longevity. Gene expression and alternative splice variants were analyzed in a genome-wide manner in the fetal brain of C57BL/6J mice (long-lived) in comparison to B6.Cg-Cav1^tm1Mls/J (congenic, short-lived) and AKR/J (inbred, short-lived) mice on day(d) 12, 15, and 17 of gestation. The analysis showed a contrasting gene expression pattern during fetal brain development in these mice. Genes related to brain development, aging, and the regulation of alternative splicing were significantly differentially regulated in the fetal brain of the short-lived compared to long-lived mice during development from d15 and d17. A significantly reduced number of splice variants was observed on d15 compared to d12 or d17 in a strain-dependent manner. An epigenetic clock analysis of d15 fetal brain identified DNA methylations that were significantly associated with single-nucleotide polymorphic sites between AKR/J and C57BL/6J strains. These methylations were associated with genes that show epigenetic changes in an age-correlated manner in mice. Together, the finding of this study suggest that fetal brain development and longevity are epigenetically linked, supporting the emerging concept of the early-life origin of longevity. Full article

Phishing email attacks are among the most common and most harmful cybersecurity attacks. With the emergence of generative AI, phishing attacks can be based on emails generated automatically, making it more difficult to detect them. That is, instead of a single email format sent to a large number of recipients, generative AI can be used to send each potential victim a different email, making it more difficult for cybersecurity systems to identify the scam email before it reaches the recipient. Here, we describe a corpus of AI-generated phishing emails. We also use different machine learning tools to test the ability of automatic text analysis to identify AI-generated phishing emails. The results are encouraging, and show that machine learning tools can identify an AI-generated phishing email with high accuracy compared to regular emails or human-generated scam emails. By applying descriptive analytics, the specific differences between AI-generated emails and manually crafted scam emails are profiled and show that AI-generated emails are different in their style from human-generated phishing email scams. Therefore, automatic identification tools can be used as a warning for the user. The paper also describes the corpus of AI-generated phishing emails that are made open to the public and can be used for consequent studies. While the ability of machine learning to detect AI-generated phishing emails is encouraging, AI-generated phishing emails are different from regular phishing emails, and therefore, it is important to train machine learning systems also with AI-generated emails in order to repel future phishing attacks that are powered by generative AI. Full article

Pinus thunbergii Parl. is an economically and medicinally important plant, as well as a world-renowned horticultural species of the Pinus genus. Pine wilt disease is a dangerous condition that affects P. thunbergii. However, understanding of the genetics underlying resistance to this disease is poor. Our findings reveal that P. thunbergii’s resistance mechanism is based on differential transcriptome responses generated by the early presence of the pathogen Bursaphelenchus xylophilus, also known as the pine wood nematode. A transcriptome analysis (RNA-seq) was performed to examine gene expression in shoot tissues from resistant and susceptible P. thunbergii trees. RNA samples were collected from the shoots of inoculated pines throughout the infection phases by the virulent Bursaphelenchus xylophilus AMA3 strain. The photosynthesis and plant–pathogen interaction pathways were significantly enriched in the first and third days after infection. Flavonoid biosynthesis was induced in response to late infestation (7 and 14 days post-infestation). Calmodulin, RBOH, HLC protein, RPS, PR1, and genes implicated in phytohormone crosstalk (e.g., SGT1, MYC2, PP2C, and ERF1) showed significant alterations between resistant and susceptible trees. Furthermore, salicylic acid was found to aid pine wood nematodes tolerate adverse conditions and boost reproduction, which may be significant for pine wood nematode colonization within pines. These findings provide new insights into how host defenses overcame pine wood nematode infection in the early stage, which could potentially contribute to the development of novel strategies for the control of pine wilt disease. Full article

MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs in plants. They play critical functions in various biological processes during plant growth and development. Salvia miltiorrhiza is a well-known traditional Chinese medicinal plant with significant medicinal, economic, and academic values. In order to elucidate the role of miRNAs in S. miltiorrhiza, six small RNA libraries from mature roots, young roots, stems, mature leaves, young leaves and flowers of S. miltiorrhiza and one degradome library from mixed tissues were constructed. A total of 184 miRNA precursors, generating 137 known and 49 novel miRNAs, were genome-widely identified. The identified miRNAs were predicted to play diversified regulatory roles in plants through regulating 891 genes. qRT-PCR and 5′ RLM-RACE assays validated the negative regulatory role of smi-miR159a in SmMYB62, SmMYB78, and SmMYB80. To elucidate the function of smi-miR159a in bioactive compound biosynthesis, smi-miR159a transgenic hairy roots were generated and analyzed. The results showed that overexpression of smi-miR159a caused a significant decrease in rosmarinic acid and salvianolic acid B contents. qRT-PCR analysis showed that the targets of smi-miR159a, including SmMYB62, SmMYB78, and SmMYB80, were significantly down-regulated, accompanied by the down-regulation of SmPAL1, SmC4H1, Sm4CL1, SmTAT1, SmTAT3, SmHPPR1, SmRAS, and SmCYP98A14 genes involved in phenolic acid biosynthesis. It suggests that smi-miR159a is a significant negative regulator of phenolic acid biosynthesis in S. miltiorrhiza. Full article

Introduction: Non-infectious erythema, or Red Breast Syndrome (RBS), has been observed on the skin where acellular dermal matrix was implanted, although the exact cause is yet to be determined. Patients and Methods: A total of 214 female patients underwent breast-conserving surgery (BCS) and volume replacement using diced acellular dermal matrix (dADM) for breast cancer between December 2017 and December 2018. After collecting and evaluating relevant clinical data, inflammation markers, along with NK cell status presented by IFN-γ secretion assay, were measured using ELISA. Results: Nineteen patients (8.88%) presented with RBS after BCS and dADM use. A significant increase of platelet-to-lymphocyte ratio was noted in the non-RBS group (p = 0.02). Compared to the RBS group (p = 0.042), the WBC level of the non-RBS group showed significant decrease over time. Eosinophil counts increased significantly at follow-up but went up higher in the RBS group. Multivariate analysis showed preoperative chemotherapy significantly increased the hazard of RBS (OR 3.274, p = 0.047 and OR 17.098, p < 0.001, respectively). Discussion: Though no causal relationship between RBS and immune status was proven, the results suggest an association between preoperative chemotherapy and RBS in addition to the possible role of eosinophilia in leading to eosinophilic dermatoses, which warrants further exploration and elucidation. Full article

Clays are a class of porous materials; their surfaces are naturally covered by moisture. Weak thermal treatment may be considered practical to remove the water molecules, changing the surface properties and making the micro- and/or mesoporosities accessible to interact with other molecules. Herein, a modulated thermogravimetric analysis (MTGA) study of the moisture behavior on the structures of five, both fibrous and laminar, clay minerals is reported. The effect of the thermal treatment at 150 °C, which provokes the release of weakly adsorbed water molecules, was also investigated. The activation energies for the removal of the adsorbed water (Ea) were calculated, and they were found to be higher, namely, from 160 to 190 kJ mol⁻¹, for fibrous clay minerals compared to lamellar structures, ranging in this latter case from 80 to 100 kJ mol⁻¹. The thermal treatment enhances the rehydration in Na-montmorillonite, stevensite, and sepiolite structures with a decrease in the energy required to remove it, while Ea increases significantly in palygorskite (from 164 to 273 kJ mol⁻¹). As a proof of concept, the MTGA results are statistically correlated, together with a full characterization of the physico-chemical properties of the five clay minerals, with the adsorption of two molecules, i.e., aflatoxin B1 (AFB1) and β-carotene. Herein, the amount of adsorbed molecules ranges from 12 to 97% for the former and from 22 to 35% for the latter, depending on the particular clay. The Ea was correlated with AFB1 adsorption with a Spearman score of −0.9. When the adsorbed water is forcibly removed, e.g., under vacuum conditions and high temperatures, the structure becomes the most important, decreasing the Spearman score between β-carotene and Ea to −0.6. Full article

The purpose of this study was to examine the biocompatibility of 3D printed materials used for additive manufacturing of rigid and flexible oral devices. Oral splints were produced and finished from six printable resins (pairs of rigid/flexible materials: KeySplint Hard [KR], KeySplint Soft [KF], V-Print Splint [VR], V-Print Splint Comfort [VF], NextDent Ortho Rigid [NR], NextDent Ortho Flex [NF]), and two types of PMMA blocks for subtractive manufacturing (Tizian Blank PMMA [TR], Tizian Flex Splint Comfort [TF]) as controls. The specimens were eluted in a cell culture medium for 7d. Human gingival fibroblasts (hGF-1) and human oral mucosal keratinocytes (hOK) were exposed to the eluates for 24 h. Cell viability, glutathione levels, apoptosis, necrosis, the cellular inflammatory response (IL-6 and PGE₂ secretion), and cell morphology were assessed. All eluates led to a slight reduction of hGF-1 viability and intracellular glutathione levels. The strongest cytotoxic response of hGF-1 was observed with KF, NF, and NR eluates (p < 0.05 compared to unexposed cells). Viability, caspase-3/7 activity, necrosis levels, and IL-6/PGE₂ secretion of hOK were barely affected by the materials. All materials showed an overall acceptable biocompatibility. hOK appeared to be more resilient to noxious agents than hGF-1 in vitro. There is insufficient evidence to generalize that flexible materials are more cytotoxic than rigid materials. From a biological point of view, 3D printing seems to be a viable alternative to milling for producing oral devices. Full article