3D Shared Matting Method for Directly Extracting Standard Organ Models from Human Body Color Volume Image

BACKGROUND

In some medical applications (e.g., virtual surgery), standard human organ models are very important and useful. Now that real human body slice image sets have been collected by several countries, it is possible to obtain real standard organ models.

INTRODUCTION

Understanding how to abandon the traditional model construction method of Photoshop sketching slice by slice and directly extracting 3D models from volume images has been an interesting and challenging issue. In this paper, a 3D color volume image matting method has been proposed to segment human body organ models.

METHODS

First, the scope of the known area will be expanded by means of propagation. Next, neighborhood sampling to find the best sampling for voxels in an unknown region will be performed and then the preliminary opacity using the sampling results will be calculated.

RESULTS

The final result will be obtained by applying local smoothing to the image.

CONCLUSION

From the experimental results, it has been observed that our method is effective for real standard organ model extraction.

Multiscale modeling of blood flow to assess neurological complications in patients supported by venoarterial extracorporeal membrane oxygenation

Computational blood flow models in large arteries elucidate valuable relationships between cardiovascular diseases and hemodynamics, leading to improvements in treatment planning and clinical decision making. One such application with potential to benefit from simulation is venoarterial extracorporeal membrane oxygenation (VA-ECMO), a support system for patients with cardiopulmonary failure. VA-ECMO patients develop high rates of neurological complications, partially due to abnormal blood flow throughout the vasculature from the VA-ECMO system. To better understand these hemodynamic changes, it is important to resolve complex local flow parameters derived from three-dimensional (3D) fluid dynamics while also capturing the impact of VA-ECMO support throughout the systemic arterial system. As high-resolution 3D simulations of the arterial network remain computationally expensive and intractable for large studies, a validated, multiscale model is needed to compute both global effects and high-fidelity local hemodynamics. In this work, we developed and demonstrated a framework to model hemodynamics in VA-ECMO patients using coupled 3D and one-dimensional (1D) models (1D→3D). We demonstrated the ability of these multiscale models to simulate complex flow patterns in specific regions of interest while capturing bulk flow throughout the systemic arterial system. We compared 1D, 3D, and 1D→3D coupled models and found that multiscale models were able to sufficiently capture both global and local hemodynamics in the cerebral arteries and aorta in VA-ECMO patients. This study is the first to develop and compare 1D, 3D, and 1D→ 3D coupled models on the larger arterial system scale in VA-ECMO patients, with potential use for other large scale applications.

Screen Printing to Create 3D Tissue Models

3D printing has revolutionized making tissue models, but the instruments are often quite expensive, and the approach can involve heat and/or shear forces that can damage cells. As a complement to more traditional 3D printing approaches, we looked at screen printing. Screen printing is an additive manufacturing technique used to pattern inks through screens supporting patterns onto different surfaces. It has a wide range of applications ranging from traditional printing to printing electric circuit boards. Taking cues from this we have developed a process of screen printing live cells along with a suitable scaffold on to different surfaces to generate in vitro models. The process is not only inexpensive and simple to use, but it also offers a wide range of advantages like the ability to use a range of bioinks limited only by their gelation time, printing on different surfaces, and the ability to autoclave all of the major components. In this paper, we present the screen assembly and the setup we used to print the cells along with the resolution and limits of features printed and the effect of the printing on the cells.

Hydrogels for 3D Neural Tissue Models: Understanding Cell-Material Interactions at a Molecular Level

The development of 3D neural tissue analogs is of great interest to a range of biomedical engineering applications including tissue engineering of neural interfaces, treatment of neurodegenerative diseases and in vitro assessment of cell-material interactions. Despite continued efforts to develop synthetic or biosynthetic hydrogels which promote the development of complex neural networks in 3D, successful long-term 3D approaches have been restricted to the use of biologically derived constructs. In this study a poly (vinyl alcohol) biosynthetic hydrogel functionalized with gelatin and sericin (PVA-SG), was used to understand the interplay between cell-cell communication and cell-material interaction. This was used to probe critical short-term interactions that determine the success or failure of neural network growth and ultimately the development of a useful model. Complex primary ventral mesencephalic (VM) neural cells were encapsulated in PVA-SG hydrogels and critical molecular cues that demonstrate mechanosensory interaction were examined. Neuronal presence was constant over the 10 day culture, but the astrocyte population decreased in number. The lack of astrocytic support led to a reduction in neural process outgrowth from 24.0 ± 1.3 μm on Day 7 to 7.0 ± 0.1 μm on Day 10. Subsequently, purified astrocytes were studied in isolation to understand the reasons behind PVA-SG hydrogel inability to support neural network development. It was proposed that the spatially restrictive nature (or tight mesh size) of PVA-SG hydrogels limited the astrocytic actin polymerization together with a cytoplasmic-nuclear translocation of YAP over time, causing an alteration in their cell cycle. This was confirmed by the evaluation of p27^/Kip1 gene that was found to be upregulated by a twofold increase in expression at both Days 7 and 10 compared to Day 3, indicating the quiescent stage of the astrocytes in PVA-SG hydrogel. Cell migration was further studied by the quantification of MMP-2 production that was negligible compared to 2D controls, ranging from 2.7 ± 2.3% on Day 3 to 5.3 ± 2.9% on Day 10. This study demonstrates the importance of understanding astrocyte-material interactions at the molecular level, with the need to address spatial constraints in the 3D hydrogel environment. These findings will inform the design of future hydrogel constructs with greater capacity for remodeling by the cell population to create space for cell migration and neural process extension.

Mini-review: advances in 3D bioprinting of vascularized constructs

3D in vitro constructs have gained more and more relevance in tissue engineering and in cancer-modeling. In recent years, with the development of thicker and more physiologically relevant tissue patches, the integration of a vascular network has become pivotal, both for sustaining the construct in vitro and to help the integration with the host tissue once implanted. Since 3D bioprinting is rising to be one of the most versatile methods to create vascularized constructs, we here briefly review the most promising advances in bioprinting techniques.

Human Retinal Microvasculature-on-a-Chip for Drug Discovery

Retinal cells within neurovascular units generate the blood-retinal barrier (BRB) to regulate the local retinal microenvironment and to limit access to inflammatory cells. Breakdown of the endothelial junctional complexes in the BRB negatively affects neuronal signaling and ultimately causes vision loss. As new therapeutics are being developed either to prevent barrier disruption or to restore barrier function, access to physiologically relevant human in vitro tissue models that recapitulate important features of barrier biology is essential for disease modeling, target validation, and toxicity assessment. Here, a tunable organ-on-a-chip model of the retinal microvasculature using human retinal microvascular endothelial cells with integrated flow is described. Automated imaging and image analysis methods are employed for facile screening of leakage mediators and cytokine inhibitors on barrier properties. The developed retinal microvasculature-on-a-chip will enable improved understanding of BRB biology and provide an additional tool for drug discovery.

The Application of Pre-operative Three-Dimensional Models in the Management of Mandibular Pathology: Is it Really Useful? An Institutional Study

Aim

To assess the usefulness of 3D models for the surgical management of mandibular pathology requiring resection with continuity defects reconstructed using reconstruction plates.

Patients and Method

A bidirectional study was conducted in 40 patients, 20 each in group 1 and 2. Group 1 included those patients taken up for resection with continuity defects and reconstruction using reconstruction plates without using 3D models and Group 2 included those patients managed similarly with 3D models. Pre-operative pathological model and mirrored model was fabricated for accurate placement and pre-bending of plates and determining the position and length of the screws. The level of understanding of the patients with regards to the diagnosis and extent of the disease (VAS 0-10), treatment planning (VAS 0-10), accuracy of fixation by a blinded surgeon (VAS 0-5), operative time, change in the mouth Opening, occlusal disturbance, implant-related complications was assessed as outcome measures and tested statistically.

Results

The level of understanding of the patients with regards to the diagnosis and extent of the disease, treatment planning, operative time and accuracy of fixation was found to be statistically significant with superior performance in Group 2. No statistical significance was elicited in the change in mouth opening. No limitation in the mandibular range of movements and occlusal disturbance was found in any patient. No implant-related complications were found during the follow-up.

Conclusion

3D model fabrication can serve as a valuable adjunct in improving clinical outcomes with minimal operating time, increased patient compliance and radiological accuracy of fixation.

Influence of rotational speed and glide path on cyclic fatigue resistance of XP-endo shaper

Aim

The aim of this study was to evaluate the effect of the different rotational speeds and creating a glide path on cyclic fatigue resistance of XP-endo Shaper® (XPS) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) at intracanal temperature.

Materials and Methods

Ninety-six XPS files were divided into 6 groups [directly used at 1000 rpm (G1) or 3000 rpm (G4), with glide path at 1000 rpm (G2) or 3000 rpm (G4), without glide path at 1000 rpm (G3) and 3000 rpm (G6)]. All the instruments were rotated in a stainless-steel artificial canal with a 75° angle of curvature, 7.5 mm radius of curvature, and 1.3 mm inner diameter until the fracture occurred. The number of cycles to failure (NCF) and the length of the fractured (LF) segments were evaluated. Weibull analysis, one-way ANOVA, and Tukey multiple comparison tests were performed with the significance level set at 0.05.

Results

NCF of 3000 rpm groups was statistically higher than that of 1000 rpm groups (P < 0.05). And time to fracture was found statistically higher in 1000 rpm as compared to 3000 rpm. The mean LF of the instruments was statistically insignificant (P > 0.05). There was no statistical difference within the groups subjected at 1000 rpm and 3000 rpm files used with or without a glide path (P > 0.05).

Conclusion

Within the limitations of this in vitro study, it was determined that XPS can be used safely even at 3000 rpm speed with or without glide path.

Three-Dimensional Models as a New Frontier for Studying the Role of Proteoglycans in the Normal and Malignant Breast Microenvironment

The extracellular matrix (ECM) provides cues to direct mammogenesis, tumourigenesis and metastatic processes. Over the past several decades, two-dimensional (2D) culture models have been invaluable in furthering our understanding of the tumor microenvironment (TME), however, they still do not accurately emulate the associated biological complexities. In contrast, three-dimensional (3D) culture models provide a more physiologically relevant platform to study relevant physicochemical signals, stromal-epithelial cell interactions, vascular and immune components, and cell-ECM interactions in the human breast microenvironment. A common thread that may weave these multiple interactions are the proteoglycans (PGs), a prominent family of molecules in breast tissue. This review will discuss how these PGs contribute to the breast cancer TME and provide a summary of the traditional and emerging technologies that have been utilized to better understand the role of PGs during malignant transformation. Furthermore, this review will emphasize the differences that PGs exhibit between normal tissues and tumor ECM, providing a rationale for the investigation of underexplored roles of PGs in breast cancer progression using state-of-the-art 3D culture models.

Advancements in sex estimation using the diaphyseal cross-sectional geometric properties of the lower and upper limbs

This paper introduces an automated method for estimating sex from the lower and upper limbs based on diaphyseal CSG properties. The proposed method was developed and evaluated using 389 femurs, 412 tibias, and 404 humeri of adult individuals from a modern Greek reference sample, the Athens Collection. The skeletal properties, which were extracted with the CSG-Toolkit, were analyzed with step-wise DFA (evaluated with LOOCV) and subsequently with RBF kernel SVM supervised learning. SVM cross-validation was based on a 20-fold stratified random sample splitting as well as a chronological split based on year of birth to further assess the effect of secular change in sex estimation capacity. Maximum cross-validated classification accuracy from step-wise DFA reached 94.8% for the femur, 94.7% for the tibia, and 97.3% for the humerus, whereas SVM cross-validated results were similar although slightly lower, mainly due to the more strict cross-validation scheme. Our results suggest that the proposed sex estimation method is reasonably robust to secular change, since there was limited loss in classification accuracy between different chronological groups, despite the presence of secular change in stature of the Greek population during the examined period. The proposed method has been implemented as a function for the GNU Octave environment, named estimate_sex, which comprises a self-intuitive graphical user interface for facilitating sex estimation and is freely available under a suitable license.

3D Bone Morphology Alters Gene Expression, Motility, and Drug Responses in Bone Metastatic Tumor Cells

Patients with advanced skeletal metastases arising from primary cancers including breast, lung, and prostate suffer from extreme pain, bone loss, and frequent fractures. While the importance of interactions between bone and tumors is well-established, our understanding of complex cell–cell and cell–microenvironment interactions remains limited in part due to a lack of appropriate 3D bone models. To improve our understanding of the influence of bone morphometric properties on the regulation of tumor-induced bone disease (TIBD), we utilized bone-like 3D scaffolds in vitro and in vivo. Scaffolds were seeded with tumor cells, and changes in cell motility, proliferation, and gene expression were measured. Genes associated with TIBD significantly increased with increasing scaffold rigidity. Drug response differed when tumors were cultured in 3D compared to 2D. Inhibitors for Integrin β3 and TGF-β Receptor II significantly reduced bone-metastatic gene expression in 2D but not 3D, while treatment with the Gli antagonist GANT58 significantly reduced gene expression in both 2D and 3D. When tumor-seeded 3D scaffolds were implanted into mice, infiltration of myeloid progenitors changed in response to pore size and rigidity. This study demonstrates a versatile 3D model of bone used to study the influence of mechanical and morphometric properties of bone on TIBD.

Production of 3D Tumor Models of Head and Neck Squamous Cell Carcinomas for Nanotheranostics Assessment

As a first approach, standard 2D cell culture techniques are usually employed for the screening of drugs and nanomaterials. Despite the easy handling, findings achieved on 2D cultures are often not efficiently translatable to in vivo preclinical investigations. Furthermore, although animal models are pivotal in preclinical studies, more strict directives have been implemented to promote the use of alternative biological systems. In this context, the development and integration into preclinical research workflow of 3D neoplasm models is particularly appealing to promote the advancement and success of therapeutics in clinical trials while reducing the number of in vivo models. Indeed, 3D tumor models bridge several discrepancies between 2D cell culture and in vivo models, among which are morphology, polarity, drug penetration, osmolality, and gene expressions. Here, we comprehensively describe a robust and high-throughput hanging drop protocol for the production of 3D models of both Human Papillomavirus (HPV)-positive and HPV-negative head and neck squamous cell carcinomas (HNSCCs). We also report the standard cascade assays for their characterization and demonstrate their significance in investigations on these aggressive neoplasms. The employment of relevant 3D cancer models is pivotal to produce more reliable and robust findings in terms of biosafety, theranostic efficacy, and biokinetics as well as to promote further knowledge on HNSCC pathophysiology.

Improving Bioprinted Volumetric Tumor Microenvironments In Vitro

Despite the great breakthroughs in the past few decades in illuminating the pathological mechanisms of cancer and in developing new anticancer drugs, it remains extremely challenging to cure most cancers. Therefore, it is imperative to develop more sophisticated and more biomimetic preclinical cancer models. 3D models combined with dynamic culture techniques show great potential to accurately emulate the volumetric tumor microenvironment (TME). Here we introduce advances in bioprinting technologies for in vitro cancer modeling and their applications. Finally, we look ahead to the remaining challenges associated with current bioprinting strategies for achieving faithful cancer modeling.

Trends in Bone Metastasis Modeling

Bone is one of the most common sites for cancer metastasis. Bone tissue is composed by different kinds of cells that coexist in a coordinated balance. Due to the complexity of bone, it is impossible to capture the intricate interactions between cells under either physiological or pathological conditions. Hence, a variety of in vivo and in vitro approaches have been developed. Various models of tumor-bone diseases are routinely used to provide valuable information on the relationship between metastatic cancer cells and the bone tissue. Ideally, when modeling the metastasis of human cancers to bone, models would replicate the intra-tumor heterogeneity, as well as the genetic and phenotypic changes that occur with human cancers; such models would be scalable and reproducible to allow high-throughput investigation. Despite the continuous progress, there is still a lack of solid, amenable, and affordable models that are able to fully recapitulate the biological processes happening in vivo, permitting a correct interpretation of results. In the last decades, researchers have demonstrated that three-dimensional (3D) methods could be an innovative approach that lies between bi-dimensional (2D) models and animal models. Scientific evidence supports that the tumor microenvironment can be better reproduced in a 3D system than a 2D cell culture, and the 3D systems can be scaled up for drug screening in the same way as the 2D systems thanks to the current technologies developed. However, 3D models cannot completely recapitulate the inter- and intra-tumor heterogeneity found in patients. In contrast, ex vivo cultures of fragments of bone preserve key cell-cell and cell-matrix interactions and allow the study of bone cells in their natural 3D environment. Moreover, ex vivo bone organ cultures could be a better model to resemble the human pathogenic metastasis condition and useful tools to predict in vivo response to therapies. The aim of our review is to provide an overview of the current trends in bone metastasis modeling. By showing the existing in vitro and ex vivo systems, we aspire to contribute to broaden the knowledge on bone metastasis models and make these tools more appealing for further translational studies.

In Vitro Modeling of Non-Solid Tumors: How Far Can Tissue Engineering Go?

In hematological malignancies, leukemias or myelomas, malignant cells present bone marrow (BM) homing, in which the niche contributes to tumor development and drug resistance. BM architecture, cellular and molecular composition and interactions define differential microenvironments that govern cell fate under physiological and pathological conditions and serve as a reference for the native biological landscape to be replicated in engineered platforms attempting to reproduce blood cancer behavior. This review summarizes the different models used to efficiently reproduce certain aspects of BM in vitro; however, they still lack the complexity of this tissue, which is relevant for fundamental aspects such as drug resistance development in multiple myeloma. Extracellular matrix composition, material topography, vascularization, cellular composition or stemness vs. differentiation balance are discussed as variables that could be rationally defined in tissue engineering approaches for achieving more relevant in vitro models. Fully humanized platforms closely resembling natural interactions still remain challenging and the question of to what extent accurate tissue complexity reproduction is essential to reliably predict drug responses is controversial. However, the contributions of these approaches to the fundamental knowledge of non-solid tumor biology, its regulation by niches, and the advance of personalized medicine are unquestionable.

A critical assessment of the potential for Structure-from-Motion photogrammetry to produce high fidelity 3D dental models

OBJECTIVES

The recent proliferation of methods of 3D model generation has enabled the development of new approaches to the analysis of dental form, function and wear. This article assesses whether Structure-from-motion (SfM) photogrammetry is capable of producing virtual 3D models of teeth of adequate quality for assessing fine scale surface details, such as dental macrowear patterns. Reference models were generated using a high resolution structured light scanner to assess the accuracy of the photogrammetric models generated.

MATERIALS AND METHODS

Dental gypsum models of the molar teeth of human individuals from St. Michael's Litten, Chichester, Post-medieval assemblage (n = 17) were used for 3D model generation. Photogrammetry was performed using Agisoft Metashape and reference 3D models were generated using a GOM ATOS 80 scanner. Focus stacking was explored as a method of enhancing 3D model detail. Differences between the photogrammetric and reference models were assessed using CloudCompare and the quality of the surface detail was examined quantitatively using Occlusal Fingerprint Analysis.

RESULTS

Photogrammetric model generation was highly replicable and the tooth models produced closely approximated the overall geometry of those derived from the structured light scanner. Dental wear facet area measurements on the photogrammetric models differed significantly, however, from those derived from the structured light scanning reference models.

DISCUSSION

Photogrammetry can create virtual dental models from which crude quantitative size and shape data can be obtained. Finer scale surface details are not accurately reproduced on SfM models using the methods outlined in the current article due to high levels of surface noise.

Modeling neoplastic disease with spheroids and organoids

Cancer is a complex disease in which both genetic defects and microenvironmental components contribute to the development, progression, and metastasization of disease, representing major hurdles in the identification of more effective and safer treatment regimens for patients. Three-dimensional (3D) models are changing the paradigm of preclinical cancer research as they more closely resemble the complex tissue environment and architecture found in clinical tumors than in bidimensional (2D) cell cultures. Among 3D models, spheroids and organoids represent the most versatile and promising models in that they are capable of recapitulating the heterogeneity and pathophysiology of human cancers and of filling the gap between conventional 2D in vitro testing and animal models. Such 3D systems represent a powerful tool for studying cancer biology, enabling us to model the dynamic evolution of neoplastic disease from the early stages to metastatic dissemination and the interactions with the microenvironment. Spheroids and organoids have recently been used in the field of drug discovery and personalized medicine. The combined use of 3D models could potentially improve the robustness and reliability of preclinical research data, reducing the need for animal testing and favoring their transition to clinical practice. In this review, we summarize the recent advances in the use of these 3D systems for cancer modeling, focusing on their innovative translational applications, looking at future challenges, and comparing them with most widely used animal models.

Radiosensitisation of Hepatocellular Carcinoma Cells by Vandetanib

Hepatocellular Carcinoma (HCC) is increasing in incidence worldwide and requires new approaches to therapy. The combination of anti-angiogenic drug therapy and radiotherapy is one promising new approach. The anti-angiogenic drug vandetanib is a tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) and RET proto-oncogene with radio-enhancement potential. To explore the benefit of combined vandetanib and radiotherapy treatment for HCC, we studied outcomes following combined treatment in pre-clinical models. Methods: Vandetanib and radiation treatment were combined in HCC cell lines grown in vitro and in vivo. In addition to 2D migration and clonogenic assays, the combination was studied in 3D spheroids and a syngeneic mouse model of HCC. Results: Vandetanib IC50s were measured in 20 cell lines and the drug was found to significantly enhance radiation cell kill and to inhibit both cell migration and invasion in vitro. In vivo, combination therapy significantly reduced cancer growth and improved overall survival, an effect that persisted for the duration of vandetanib treatment. Conclusion: In 2D and 3D studies in vitro and in a syngeneic model in vivo, the combination of vandetanib plus radiotherapy was more efficacious than either treatment alone. This new combination therapy for HCC merits evaluation in clinical trials.

Extracellular Matrix Mimics Using Hyaluronan-Based Biomaterials

Hyaluronan (HA) is a critical element of the extracellular matrix (ECM). The regulated synthesis and degradation of HA modulates the ECM chemical and physical properties that, in turn, influence cellular behavior. HA triggers signaling pathways associated with the adhesion, proliferation, migration, and differentiation of cells, mediated by its interaction with specific cellular receptors or by tuning the mechanical properties of the ECM. This review summarizes the recent advances on strategies used to mimic the HA present in the ECM to study healthy or pathological cellular behavior. This includes the development of HA-based 2D and 3D in vitro tissue models for the seeding and encapsulation of cells, respectively, and HA particles as carriers for the targeted delivery of therapeutic agents.

The importance of spheroids in analyzing nanomedicine efficacy

The use of nanomedicines for cancer treatment holds a great potential due to their improved efficacy and safety. During the nanomedicine preclinical in vitro evaluation stage, these are mainly tested on cell culture monolayers. However, these 2D models are an unrealistic representation of the in vivo tumors, leading to an inaccurate screening of the candidate formulations. To address this problem, spheroids are emerging as an additional tool to validate the efficacy of new therapeutics due to the ability of these 3D in vitro cancer models to mimic the key features displayed by in vivo solid tumors. In this review, the application of spheroids for the evaluation of nanomedicines' physicochemical properties and therapeutic efficacy is discussed.

Endogenously-Activated Ultrasmall-in-Nano Therapeutics: Assessment on 3D Head and Neck Squamous Cell Carcinomas

Negative or positive HPV-associated Head and Neck Squamous Cell Carcinomas (HNSCCs) are high recurrence neoplasms usually resulting in a poor prognosis, mainly due to metastasis formation. Despite the low overall patient survival rate and the severe side effects, the treatment of choice is still cisplatin-based chemotherapy. Here, we report a straightforward protocol for the production of high throughput 3D models of negative or positive HPV-associated HNSCCs, together with their employment in the therapeutic evaluation of gold ultrasmall-in-nano architectures comprising an endogenously-activatable cisplatin prodrug. Beyond enhancing the biosafety of cisplatin, our approach paves the way for the establishment of synergistic co-therapies for HNSCCs based on excretable noble metals.

Organoid Models of Glioblastoma to Study Brain Tumor Stem Cells

Glioblastoma represents an aggressive form of brain cancer characterized by poor prognosis and a 5-year survival rate of only 3–7%. Despite remarkable advances in brain tumor research in the past decades, very little has changed for patients, due in part to the recurrent nature of the disease and to the lack of suitable models to perform genotype-phenotype association studies and personalized drug screening. In vitro culture of cancer cells derived from patient biopsies has been fundamental in understanding tumor biology and for testing the effect of various drugs. These cultures emphasize the role of in vitro cancer stem cells (CSCs), which fuel tumor growth and are thought to be the cause of relapse after treatment. However, it has become clear over the years that a 2D monolayer culture of these CSCs has certain disadvantages, including the lack of heterogeneous cell-cell and cell-environment interactions, which can now be partially overcome by the introduction of 3D organoid cultures. This is a novel and expanding field of research and in this review, I describe the emerging 3D models of glioblastoma. I also discuss their potential to advance our knowledge of tumor biology and CSC heterogeneity, while debating their current limitations.

In vitro modeling of the neurovascular unit: advances in the field

The blood–brain barrier (BBB) is a fundamental component of the central nervous system. Its functional and structural integrity is vital in maintaining the homeostasis of the brain microenvironment. On the other hand, the BBB is also a major hindering obstacle for the delivery of effective therapies to treat disorders of the Central Nervous System (CNS). Over time, various model systems have been established to simulate the complexities of the BBB. The development of realistic in vitro BBB models that accurately mimic the physiological characteristics of the brain microcapillaries in situ is of fundamental importance not only in CNS drug discovery but also in translational research. Successful modeling of the Neurovascular Unit (NVU) would provide an invaluable tool that would aid in dissecting out the pathological factors, mechanisms of action, and corresponding targets prodromal to the onset of CNS disorders. The field of BBB in vitro modeling has seen many fundamental changes in the last few years with the introduction of novel tools and methods to improve existing models and enable new ones. The development of CNS organoids, organ-on-chip, spheroids, 3D printed microfluidics, and other innovative technologies have the potential to advance the field of BBB and NVU modeling. Therefore, in this review, summarize the advances and progress in the design and application of functional in vitro BBB platforms with a focus on rapidly advancing technologies.

Errors in femoral anteversion, femoral offset, and vertical offset following robot-assisted total hip arthroplasty

The objectives were to determine errors in femoral anteversion (FA), femoral offset (FO), and vertical offset (VO) with robot-assisted total hip arthroplasty (THA) and how consistently these errors are within clinically desirable limits of ±5° and ±5 mm. After preoperative planning, robot-assisted THAs were performed on twelve cadaveric specimens. The error between achieved and planned component placements was used to determine bias (mean error) and precision (SD of error). The percent of the population within clinically desirable limits was determined. Bias of 1.5° and 2.7 mm occurred for FA and VO, respectively. Precision was 1.2° for FA and better than 1.5 mm for FO and VO. The percent of population within clinically desirable limits was at least 95% for FA and at least 99% for FO. With limits of ±7 mm, at least 95% of the population was within these limits for VO. Robot-assisted THA may improve clinical outcomes.

Secular evolution of femoral morphology from a clinical perspective

INTRODUCTION

Intramedullary nailing is the surgical method of choice for the treatment of proximal femur or femoral shaft fractures. Implant manufacturers aim to design implants fitting for the broadest possible population segment. As complete morphological data sets of long bones are not widely available, anatomical collections of historical dry bone specimens may represent abundant additional sources of morphological three-dimensional (3D) data for implant design, provided they are consistent with present populations. This study aims to investigate secular trends and age-related changes of femoral morphology of the Caucasian population over the past 800 years.

MATERIALS AND METHODS

Computer graphical measurements of 3D-datasets of right and left femora derived from computed tomography (CT) scans, representative of the present Caucasian population, were compared to computer graphical measurements of 3D-datasets of right and left femora derived from CT scans of specimens from a historical medieval European bone collection.

RESULTS

Clinically relevant parameters of historical medieval European femora were found mostly consistent with correlative data of the present Caucasian population. Additionally, for some of the evaluated parameters, particularly anteversion, morphological differences significantly correlated to individual age and sex could be identified, whereas other parameters such as caput-collum-diaphyseal angle or radius of anterior femoral bowing were not correlated to individual age or sex.

CONCLUSION

The findings suggest that more recent historical specimen collections may be a convenient and easily accessible source of new 3D morphological data, as well as to complement existing data, to be used by researchers and manufacturers for the development of intramedullary femoral nails.

Functionality of primary hepatic non-parenchymal cells in a 3D spheroid model and contribution to acetaminophen hepatotoxicity

In addition to hepatocytes, the liver comprises a host of specialised non-parenchymal cells which are important to consider in the development of in vitro models which are both physiologically and toxicologically relevant. We have characterized a 3D co-culture system comprising primary human hepatocytes (PHH) and non-parenchymal cells (NPC) and applied it to the investigation of acetaminophen-induced toxicity. Firstly, we titrated ratios of PHH:NPC and confirmed the presence of functional NPCs via both immunohistochemistry and activation with both LPS and TGF-β. Based on these data we selected a ratio of 2:1 PHH:NPC for further studies. We observed that spheroids supplemented with NPCs were protected against acetaminophen (APAP) toxicity as determined by ATP (up to threefold difference in EC₅₀ at day 14 compared to hepatocytes alone) and glutathione depletion, as well as miR-122 release. APAP metabolism was also altered in the presence of NPCs, with significantly lower levels of APAP-GSH detected. Expression of several CYP450 enzymes involved in the bioactivation of APAP was also lower in NPC-containing spheroids. Spheroids containing NPCs also expressed higher levels of miRNAs which have been implicated in APAP-induced hepatotoxicity, including miR-382 and miR-155 which have potential roles in liver regeneration and inflammation, respectively. These data indicate that the interaction between hepatocytes and NPCs can have significant metabolic and toxicological consequences important for the correct elucidation of hepatic safety mechanisms.

Movement and volume of infrapatellar fat pad and knee kinematics during quasi-static knee extension at 30 and 0° flexion in young healthy individuals

INTRODUCTION

The purpose of this study was to determine the changes in the shape and volume of the infrapatellar fat pad (IPFP) associated with knee flexion angle in young healthy individuals.

METHODS

Young, healthy individuals without a history of knee injuries participated in this cross-sectional study. Behavior of the IPFP was quantified using three-dimensional (3D) models of the IPFP, patella, patellar tendon, femur, and tibia obtained from MRI taken at 0° and 30° flexion. The outcomes were movement and volume change of the IPFP, movement of the patella and the tibia, and change of the patellar tendon angle and length.

RESULTS

The anterior surface of the IPFP significantly moved anteriorly by 5.23 mm (p = .003) between 30° and 0°. Change in the volume of the IPFP was significantly increased or decreased in eight hyperoctants defined by the tibial coordinate system. The IPFP moved from the postero-supero hyperoctants to anterior hyperoctants. Significant correlations were observed between the IPFP and mobility of the patella, patellar tendon or tibia.

CONCLUSION

The IPFP moves antero-inferiorly during quasi-static knee extension from 30 to 0° in young healthy individuals. Comparisons of IPFP behavior between the healthy and pathological knees may help us understand the role of IPFP and problems caused by IPFP contracture in future studies.

Liver Cancer: Current and Future Trends Using Biomaterials

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer diagnosed and the second leading cause of death worldwide. Despite advancement in current treatments for HCC, the prognosis for this cancer is still unfavorable. This comprehensive review article focuses on all the current technology that applies biomaterials to treat and study liver cancer, thus showing the versatility of biomaterials to be used as smart tools in this complex pathologic scenario. Specifically, after introducing the liver anatomy and pathology by focusing on the available treatments for HCC, this review summarizes the current biomaterial-based approaches for systemic delivery and implantable tools for locally administrating bioactive factors and provides a comprehensive discussion of the specific therapies and targeting agents to efficiently deliver those factors. This review also highlights the novel application of biomaterials to study HCC, which includes hydrogels and scaffolds to tissue engineer 3D in vitro models representative of the tumor environment. Such models will serve to better understand the tumor biology and investigate new therapies for HCC. Special focus is given to innovative approaches, e.g., combined delivery therapies, and to alternative approaches-e.g., cell capture-as promising future trends in the application of biomaterials to treat HCC.

A Comparison of the Influence of Vegetation Cover on the Precision of an UAV 3D Model and Ground Measurement Data for Archaeological Investigations: A Case Study of the Lepelionys Mound, Middle Lithuania

The aim of this research was to conduct a comparative analysis of the precision of ground geodetic data versus the three-dimensional (3D) measurements from unmanned aerial vehicles (UAV), while establishing the impact of herbaceous vegetation on the UAV 3D model. Low (up to 0.5 m high) herbaceous vegetation can impede the establishment of the anthropogenic roughness of the surface. The identification of minor surface alterations, which enables the determination of their anthropogenic origin, is of utmost importance in archaeological investigations. Vegetation cover is regarded as one of the factors influencing the identification of such minor forms of relief. The research was conducted on the Lepelionys Mound (Prienai District Municipality, Lithuania). Ground measurements were obtained using Trimble GPS, and UAV “Inspire 1” was used for taking aerial photographs. Following the data from the ground measurements and aerial photographs, large scale surface maps were drawn and the errors in the measurement of the position of the isolines were compared. The results showed that the largest errors in the positional measurements of fixed objects were conditioned by the height of grass. Grass with a height of up to 0.1 m resulted in discrepancies of up to 0.5 m, whereas grass that was up to 0.5 m high led to discrepancies up to 1.3 m high.

Investigation of pelvic symmetry using CAD software

Severe pelvic fractures often prove difficult for surgeons as they require patient-specific surgical treatment plans and customized equipment. Developing virtual patient-specific 3D pelvis models would ease the surgical planning process and enable development of custom fixation plates. This paper aims to examine pelvic symmetry to conclude whether the contralateral side may be used as a reference model for the fractured side of the pelvis. Fourteen subjects with intact pelvises were involved in this study. CT scans of the pelvises were converted to 3D models and the right sides of the pelvises were reflected and aligned with the left sides. A deviation analysis was then performed for each set of models and results showed that the average root mean square (RMS) of values was 1.14 ± 0.26 mm and the average percentage of points below a deviation threshold of ± 2 mm was 91.9 ± 5.55%. The deviation color maps (DCMs) showed that the largest deviations were on the non-articular surfaces. The volume and surface area of each model were also examined and showed no significant differences between left and right sides. These results indicate that the pelvis displays bilateral symmetry and this concept can be used to develop fully intact patient-specific 3D pelvis models for fracture reconstruction using the unfractured contralateral side. Graphical Abstract.

The CYSMA web server: An example of integrative tool for in silico analysis of missense variants identified in Mendelian disorders

Exome sequencing used for molecular diagnosis of Mendelian disorders considerably increases the number of missense variants of unclear significance, whose pathogenicity can be assessed by a variety of prediction tools. As the performance of algorithms may vary according to the datasets, complementary specific resources are needed to improve variant interpretation. As a model, we were interested in the cystic fibrosis transmembrane conductance regulator gene (CFTR) causing cystic fibrosis, in which at least 40% of missense variants are reported. Cystic fibrosis missense analysis (CYSMA) is a new web server designed for online estimation of the pathological relevance of CFTR missense variants. CYSMA generates a set of computationally derived data, ranging from evolutionary conservation to functional observations from three-dimensional structures, provides all available allelic frequencies, clinical observations, and references for functional studies. Compared to software classically used in analysis pipelines on a dataset of 141 well-characterized missense variants, CYSMA was the most efficient tool to discriminate benign missense variants, with a specificity of 85%, and very good sensitivity of 89%. These results suggest that such integrative tools could be adapted to numbers of genes involved in Mendelian disorders to improve the interpretation of missense variants identified in the context of diagnosis.

The Biological Effects of Complete Gasoline Engine Emissions Exposure in a 3D Human Airway Model (MucilAirTM) and in Human Bronchial Epithelial Cells (BEAS-2B)

The biological effects induced by complete engine emissions in a 3D model of the human airway (MucilAirTM) and in human bronchial epithelial cells (BEAS-2B) grown at the air-liquid interface were compared. The cells were exposed for one or five days to emissions generated by a Euro 5 direct injection spark ignition engine. The general condition of the cells was assessed by the measurement of transepithelial electrical resistance and mucin production. The cytotoxic effects were evaluated by adenylate kinase (AK) and lactate dehydrogenase (LDH) activity. Phosphorylation of histone H2AX was used to detect double-stranded DNA breaks. The expression of the selected 370 relevant genes was analyzed using next-generation sequencing. The exposure had minimal effects on integrity and AK leakage in both cell models. LDH activity and mucin production in BEAS-2B cells significantly increased after longer exposures; DNA breaks were also detected. The exposure affected CYP1A1 and HSPA5 expression in MucilAirTM. There were no effects of this kind observed in BEAS-2B cells; in this system gene expression was rather affected by the time of treatment. The type of cell model was the most important factor modulating gene expression. In summary, the biological effects of complete emissions exposure were weak. In the specific conditions used in this study, the effects observed in BEAS-2B cells were induced by the exposure protocol rather than by emissions and thus this cell line seems to be less suitable for analyses of longer treatment than the 3D model.

Pyridine-Containing Macrocycles Display MMP-2/9 Inhibitory Activity and Distinct Effects on Migration and Invasion of 2D and 3D Breast Cancer Models

The role of metalloproteinases (MMPs) on the migration and invasion of cancer cells has been correlated with tumor aggressiveness, namely with the up-regulation of MMP-2 and 9. Herein, two pyridine-containing macrocyclic compounds, [15]pyN₅ and [16]pyN₅, were synthesized, chemically characterized and evaluated as potential MMP inhibitors for breast cancer therapy using 3D and 2D cellular models. [15]pyN₅ and [16]pyN₅ (5–20 µM) showed a marked inhibition of MMPs activity (100% at concentrations ≥ 7.5 μM) when compared to ARP-100, a known MMP inhibitor. The inhibitory activity of [15]pyN₅ and [16]pyN₅ was further supported through in silico docking studies using Goldscore and ChemPLP scoring functions. Moreover, although no significant differences were observed in the invasion studies in the presence of all MMPs inhibitors, cell migration was significantly inhibited by both pyridine-containing macrocycles at concentrations above 5 μM in 2D cells (p < 0.05). In spheroids, the same effect was observed, but only with [16]pyN₅ at 20 μM and ARP-100 at 40 μM. Overall, [15]pyN₅ and [16]pyN₅ led to impaired breast cancer cell migration and revealed to be potential inhibitors of MMPs 2 and 9.

Catalytic inhibition of KDM1A in Ewing sarcoma is insufficient as a therapeutic strategy

BACKGROUND

Ewing sarcoma and desmoplastic small round cell tumors (DSRCT) are rare and clinically aggressive sarcomas usually characterized by oncogenic fusion proteins involving EWS. Emerging studies of Ewing sarcoma have demonstrated EWS-FLI1-driven chromatin remodeling as a key aspect of tumorigenicity. In particular, the lysine-specific demethylase KDM1A/LSD1 is linked to transcriptional regulation of target genes orchestrated by the EWS portion of the fusion protein interacting with repressive chromatin-remodeling complexes. Consistent with this model, depletion of KDM1A supports it is a molecular therapeutic target in Ewing sarcoma cells, but effective drugs need to be identified.

PROCEDURE

A comprehensive phenotypic analysis of the effects of catalytic KDM1A inhibitors ORY-1001 and GSK2879552, including clinically relevant doses, was carried out in 2D and 3D spheroid models of Ewing sarcoma and DSRCT.

RESULTS

Catalytic inhibition of KDM1A did not affect cell viability in 2D and 3D assays and had no impact on invasion in a 3D assay.

CONCLUSIONS

Overall, evidence presented here does not support inhibition of KDM1A catalytic demethylase activity as an effective therapeutic strategy for Ewing sarcoma or DSRCT. However, roles of KDM1A beyond its demethylase activity should be considered for these sarcomas.

3D Models Revolutionizing Surgical Outcomes in Oral and Maxillofacial Surgery: Experience at Our Center

Introduction

New technological advances have revolutionized the field of oral and maxillofacial surgery. The three-dimensional (3D) models are new technological breakthroughs which have equipped the oral and maxillofacial surgeon to effectively reproduce or improve preoperative form and function. They have also allowed the surgeon to achieve minimal operative and postoperative morbidity.

Materials and methods

In this case series, we present the clinical application and benefits of 3D models that are used for the surgical planning and execution of surgery in treating a case of mid-face deficiency and for the treatment of extensive jaw pathologies using reconstruction plate bent preoperatively, which contributed to improved surgical outcomes and patient satisfaction.

Creating a 3D Learning Tool for the Growth and Development of the Craniofacial Skeleton

Advances in technology are facilitating wider access to delicate, and often irreplaceable, anatomy specimens for teaching. Moreover, 3-dimensional (3D) models and interactive applications may help students to understand the spatial arrangement of complex 3D anatomical structures in a way not afforded by the 2-dimensional (2D) textbook images of traditional teaching.Historical specimens from the University of Glasgow's Museum of Anatomy were digitised for the creation of a 3D learning tool to help students better understand the growth and development of the juvenile skull. The overarching goal of this project was to assess whether interactive 3D applications can provide a useful tool for teaching more complex, non-static, anatomy subjects such as growth and development.The application received positive feedback from the small test group of 12 anatomy students. The majority of participants strongly agreed that the application helped them learn more about the human skull and they positively rated the use of 3D models in helping them learn about the position and structure of anatomical features, and in comparing skulls at different stages of development. Following on from this positive feedback, further tests could be conducted to assess if this 3D application confers an advantage in student learning over traditional teaching methods.

Comparison of cartilage and bone morphological models of the ankle joint derived from different medical imaging technologies

Background

Accurate geometrical models of bones and cartilage are necessary in biomechanical modelling of human joints, and in planning and designing of joint replacements. Image-based subject-specific model development requires image segmentation, spatial filtering and 3-dimensional rendering. This is usually based on computed tomography (CT) for bone models, on magnetic resonance imaging (MRI) for cartilage models. This process has been reported extensively in the past, but no studies have ever compared the accuracy and quality of these models when obtained also by merging different imaging modalities. The scope of the present work is to provide this comparative analysis in order to identify optimal imaging modality and registration techniques for producing 3-dimensional bone and cartilage models of the ankle joint.

Methods

One cadaveric leg was instrumented with multimodal markers and scanned using five different imaging modalities: a standard, a dual-energy and a cone-beam CT (CBCT) device, and a 1.5 and 3.0 Tesla MRI devices. Bone, cartilage, and combined bone and cartilage models were produced from each of these imaging modalities, and registered in space according to matching model surfaces or to corresponding marker centres. To assess the quality in overall model reconstruction, distance map analyses were performed and the difference between model surfaces obtained from the different imaging modalities and registration techniques was measured.

Results

The registration between models worked better with model surface matching than corresponding marker positions, particularly with MRI. The best bone models were obtained with the CBCT. Models with cartilage were defined better with the 3.0 Tesla than the 1.5 Tesla. For the combined bone and cartilage models, the colour maps and the numerical results from distance map analysis (DMA) showed that the smallest distances and the largest homogeneity were obtained from the CBCT and the 3.0 T MRI via model surface registration.

Conclusions

These observations are important in producing accurate bone and cartilage models from medical imaging and relevant for applications such as designing of custom-made ankle replacements or, more in general, of implants for total as well as focal joint replacements.

Review on biofabrication and applications of heterogeneous tumor models

Resolving the origin and development of tumor heterogeneity has proven to be a crucial challenge in cancer research. In vitro tumor models have been widely used for both scientific and clinical research. Currently, tumor models based on 2D cell culture, animal models, and 3D cell-laden constructs are widely used. Heterogeneous tumor models, which consist of more than one cell type and mimic cell-cell as well as cell-matrix interactions, are attracting increasing attention. Heterogeneous tumor models can serve as pathological models to study the microenvironment and tumor development such as tumorigenesis, invasiveness, and malignancy. They also provide disease models for drug screening and personalized therapy. In this review, the current techniques, models, and oncological applications regarding 3D heterogeneous tumor models are summarized and discussed.

Anatomy Visualizations Using Stereopsis: Current Methodologies in Developing Stereoscopic Virtual Models in Anatomical Education

Technology for developing three-dimensional (3D) virtual models in anatomical sciences education has seen a great improvement in recent years. Various data used for creating stereoscopic virtual models have also been constantly improving. This paper focuses specifically on the methodologies of creating stereoscopic virtual models and the techniques and materials used in developing stereoscopic virtual models from both our previous studies and other published literature. The presentation and visualization of stereoscopic models are highlighted, and the benefits and limitations of stereoscopic models are discussed. The practice of making 3D measurements on the lengths, angles, and volumes of models can potentially be used to help predict typical measurement parameters of anatomical structures and for the placement of surgical instruments. Once stereoscopic virtual models have been constructed, their visualization and presentation can be implemented in anatomy education and clinical surgical trainings.

Cell Type-Specific TGF-β Mediated EMT in 3D and 2D Models and Its Reversal by TGF-β Receptor Kinase Inhibitor in Ovarian Cancer Cell Lines

Transcriptome profiling of 3D models compared to 2D models in various cancer cell lines shows differential expression of TGF-β-mediated and cell adhesion pathways. Presence of TGF-β in these cell lines shows an increased invasion potential which is specific to cell type. In the present study, we identified exogenous addition of TGF-β can induce Epithelial to Mesenchymal Transition (EMT) in a few cancer cell lines. RNA sequencing and real time PCR were carried out in different ovarian cancer cell lines to identify molecular profiling and metabolic profiling. Since EMT induction by TGF-β is cell-type specific, we decided to select two promising ovarian cancer cell lines as model systems to study EMT. TGF-β modulation in EMT and cancer invasion were successfully depicted in both 2D and 3D models of SKOV3 and CAOV3 cell lines. Functional evaluation in 3D and 2D models demonstrates that the addition of the exogenous TGF-β can induce EMT and invasion in cancer cells by turning them into aggressive phenotypes. TGF-β receptor kinase I inhibitor (LY364947) can revert the TGF-β effect in these cells. In a nutshell, TGF-β can induce EMT and migration, increase aggressiveness, increase cell survival, alter cell characteristics, remodel the Extracellular Matrix (ECM) and increase cell metabolism favorable for tumor invasion and metastasis. We concluded that transcriptomic and phenotypic effect of TGF-β and its inhibitor is cell-type specific and not cancer specific.

Nerve Growth Factor Induces Proliferation and Aggressiveness In Prostate Cancer Cells

Resistance to hormone therapy and disease progression is the major challenge in clinical management of prostate cancer (PC). Drugs currently used in PC therapy initially show a potent antitumor effects, but PC gradually develops resistance, relapses and spreads. Most patients who fail primary therapy and have recurrences eventually develop castration-resistant prostate cancer (CRPC), which is almost incurable. The nerve growth factor (NGF) acts on a variety of non-neuronal cells by activating the NGF tyrosine-kinase receptor, tropomyosin receptor kinase A (TrkA). NGF signaling is deregulated in PC. In androgen-dependent PC cells, TrkA mediates the proliferative action of NGF through its crosstalk with the androgen receptor (AR). Epithelial PC cells, however, acquire the ability to express NGF and TrkA, as the disease progresses, indicating a role for NGF/TrkA axis in PC progression and androgen-resistance. We here report that once activated by NGF, TrkA mediates proliferation, invasiveness and epithelial-mesenchymal transition (EMT) in various CRPC cells. NGF promotes organoid growth in 3D models of CRPC cells, and specific inhibition of TrkA impairs all these responses. Thus TrkA represents a new biomarker to target in CRPC.

Organoids are promising tools for species-specific in vitro toxicological studies

Organoids are three-dimensional self-aggregating structures generated from stem cells (SCs) or progenitor cells in a process that recapitulates molecular and cellular stages of early organ development. The differentiation process leads to the appearance of specialized mature cells and is connected with changes in the organoid internal structure rearrangement and self-organization. The formation of organ-specific structures in vitro with highly ordered architecture is also strongly influenced by the extracellular matrix. These features make organoids as a powerful model for in vitro toxicology. Nowadays this technology is developing very quickly. In this review we present, from a toxicological and species-specific point of view, the state of the art of organoid generation from adult SCs and pluripotent SCs: embryonic SCs or induced pluripotent SCs. The current culture organoid techniques are discussed for their main advantages, disadvantages and limitations. In the second part of the review, we concentrated on the characterization of species-specific organoids generated from tissue-specific SCs of different sources: mammary (bovine), epidermis (canine), intestinal (porcine, bovine, canine, chicken) and liver (feline, canine).

Human induced pluripotent stem cell models for the study and treatment of Duchenne and Becker muscular dystrophies

Duchenne and Becker muscular dystrophies are the most common muscle diseases and are both currently incurable. They are caused by mutations in the dystrophin gene, which lead to the absence or reduction/truncation of the encoded protein, with progressive muscle degeneration that clinically manifests in muscle weakness, cardiac and respiratory involvement and early death. The limits of animal models to exactly reproduce human muscle disease and to predict clinically relevant treatment effects has prompted the development of more accurate in vitro skeletal muscle models. However, the challenge of effectively obtaining mature skeletal muscle cells or satellite stem cells as primary cultures has hampered the development of in vitro models. Here, we discuss the recently developed technologies that enable the differentiation of skeletal muscle from human induced pluripotent stem cells (iPSCs) of Duchenne and Becker patients. These systems recapitulate key disease features including inflammation and scarce regenerative myogenic capacity that are partially rescued by genetic and pharmacological therapies and can provide a useful platform to study and realize future therapeutic treatments. Implementation of this model also takes advantage of the developing genome editing field, which is a promising approach not only for correcting dystrophin, but also for modulating the underlying mechanisms of skeletal muscle development, regeneration and disease. These data prove the possibility of creating an accurate Duchenne and Becker in vitro model starting from iPSCs, to be used for pathogenetic studies and for drug screening to identify strategies capable of stopping or reversing muscular dystrophinopathies and other muscle diseases.

Pre-clinical Models for Studying the Interaction Between Mesenchymal Stromal Cells and Cancer Cells and the Induction of Stemness

Mesenchymal stromal cells (MSC) have essential functions in building and supporting the tumour microenvironment, providing metastatic niches, and maintaining cancer hallmarks, and it is increasingly evident that the study of the role of MSC in cancer is crucial for paving the way to clinical opportunities for novel anti-cancer therapies. To date, the vast majority of preclinical models that have been used for studying the effect of reactive MSC on cancer growth, metastasis, and response to therapy has been mainly based on in vitro flat biology, including the co-culturing with cell compartmentalization or with cell-to-cell contact, and on in vivo cancer models with different routes of MSC inoculation. More complex in vitro 3D models based on spheroid structures that are formed by intermingled MSC and tumour cells are also capturing the interest in cancer research. These are innovative culture systems tailored on the specific tumour type and that can be combined with a synthetic extracellular matrix, or included in in silico technologies, to more properly mimic the in vivo biological, spatial, biochemical, and biophysical features of tumour tissues. In this review, we summarized the most popular and currently available preclinical models for evaluating the role of MSC in cancer and their specific suitability, for example, in assaying the MSC-driven induction of epithelial-to-mesenchymal transition or of stem-like traits in cancer cells. Finally, we enlightened the need to carefully consider those parameters that might unintentionally strongly affect the secretome in MSC-cancer interplay and introduce confounding variables for the interpretation of results.

The 'Ins and Outs' of Early Preclinical Models for Brain Tumor Research: Are They Valuable and Have We Been Doing It Wrong?

In this perspective, we congratulate the international efforts to highlight critical challenges in brain tumor research through a recent Consensus Statement. We also illustrate the importance of developing more accurate and clinically relevant early translational in vitro brain tumor models—a perspective given limited emphasis in the Consensus Statement, despite in vitro models being widely used to prioritize candidate therapeutic strategies prior to in vivo studies and subsequent clinical trials. We argue that successful translation of effective novel treatments into the clinic will require investment into the development of more predictive early pre-clinical models. It is in the interest of researchers, clinicians, and ultimately, patients that the most promising therapeutic candidates are identified and translated toward use in the clinic. Highlighting the value of early pre-clinical brain tumor models and debating how such models can be improved is of the utmost importance to the neuro-oncology research community and cancer research more broadly.

Evaluation of the Applicability of 3d Models as Perceived by the Students of Health Sciences

The methodology and style of teaching anatomy in the faculties of Health Sciences is evolving due to the changes being introduced as a result of the application of new technologies. This brings a more positive attitude in the students, enabling an active participation during the lessons. One of these new technologies is the creation of 3D models that reliably recreates the anatomical details of real bone pieces and allow access of anatomy students to bone pieces that are not damaged and possess easily identifiable anatomical details. In our work, we have presented previously created 3D models of skull and jaw to the students of anatomy in the Faculties of Health Sciences of the University of Salamanca, Spain. The faculties included were odontology, medicine, occupational therapy nursing, health sciences and physiotherapy. A survey was carried out to assess the usefulness of these 3D models in the practical study of anatomy. The total number of students included in the survey was 280.The analysis of the results presents a positive evaluation about the use of 3D models by the students studying anatomy in different Faculties of Health Sciences.

Acquisition of 3D models with submillimeter-sized features from SEM images by use of photogrammetry: A dimensional comparison to microtomography

The use of three-dimensional models for analysis has been increasing in various fields. This study aimed to analyze the process of acquiring 3D meshes by photogrammetry using scanning electron microscopy (SEM) images. 3D models were reconstructed from different numbers of SEM images using a free photogrammetry software. The 3D models obtained were aligned and compared quantitatively to a model obtained by microtomography (microCT). The results suggest that it is possible to reconstruct 3D photogrammetric models with micrometric precision using SEM. However, the error depends on the number of images used for 3D reconstruction (and on the rotation angle). The best result obtained by photogrammetry at 9° step showed a percentage error of 0.3%. The worst result (27°) had a 1.4% error compared to those obtained by microCT. SEM photogrammetry is capable of providing surface details almost as accurate as microCT and therefore, it can be an interesting alternative for the analysis of external surfaces.

Inter-observer reliability of alternative diagnostic methods for proximal humerus fractures: a comparison between attending surgeons and orthopedic residents in training

Background

Proximal humerus fractures are frequent, and several studies show low diagnostic agreement among the observers, as well as an inaccurate classification of these lesions. The divergences are generally correlated with the experience of the surgeons as well as the diagnostic methods used. This paper challenges these problems including alternative diagnostic methods such as 3D models and augmented reality (holography) and including the observers’ period of medical experience as a factor.

Methods

Twenty orthopedists (ten experts in shoulder surgery and ten experts in traumatology) and thirty resident physicians in orthopedics classified nine proximal humerus fractures randomly distributed as x-ray, tomographies, 3D models and holography, using AO/ASIF and Neer’s classification. In the end, we evaluated the intra- and inter-observer agreement between diagnostic methods and whether the experience of the observers interfered in the evaluations and the classifications used.

Results

We found overall kappa coefficients ranging from 0.241 (fair) to 0.624 (substantial) between the two classifications (AO / ASIF and Neer), concerning the diagnostic methods used. We identified image modality differences (p = 0.017), where 3D models presented an average kappa coefficient value superior to that of tomographies. There were no differences between kappa scores for x-ray and holography compared to the others. The kappa scores for AO / ASIF classification and Neer classification and subdivided by observer period of experience showed no differences concerning the diagnostic method used.

Conclusions

3D models can substantially improve diagnostic agreement for proximal humerus fractures evaluation among experts or resident physicians. The holography showed good agreement between the experts and can be a similar option to x-ray and tomography in the evaluation and classification of these fractures. The observers’ period of experience did not improve the diagnostic agreement between the image modalities studied.

Trial registration

Registered in the Brazil Platform under no. CAAE 88912318.1.0000.5487.

Attenuation of doxorubicin-induced cardiotoxicity in a human in vitro cardiac model by the induction of the NRF-2 pathway

Dose-dependent cardiotoxicity is the leading adverse reaction seen in cancer patients treated with doxorubicin. Currently, dexrazoxane is the only approved drug that can partially protect against this toxicity in patients, however, its administration is restricted to those patients receiving a high cumulative dose of anthracyclines. Investigations into the mechanisms of cardiotoxicity and efforts to improve cardioprotective strategies have been hindered by the limited availability of a phenotypically relevant in vitro adult human cardiac model system. Here, we adapted a readily reproducible, functional 3D human multi-cell type cardiac system to emulate patient responses seen with doxorubicin and dexrazoxane. We show that administration of two NRF2 gene inducers namely the semi-synthetic triterpenoid Bardoxolone methyl, and the isothiocyanate sulfurophane, result in cardioprotection against doxorubicin toxicity comparable to dexrazoxane as evidenced by an increase in cell viability and a decrease in the production of reactive oxygen species. We further show a synergistic attenuation of cardiotoxicity when the NRF2 inducers and dexrazoxane are used in tandem. Taken together, our data indicate that the 3D spheroid is a suitable model to investigate drug induced cardiotoxicity and we reveal an essential role of the NRF2 pathway in cardioprotection providing a novel pharmacological mechanism and intervention route towards the alleviation of doxorubicin-induced toxicity.

Standard methods for creating digital skeletal models using structure-from-motion photogrammetry

OBJECTIVES

This article assesses best practices for producing 3D digital cranial models through structure-from-motion (SfM) photogrammetry, and whether the metric accuracy and overall presentation of photogrammetric models are comparable to physical crania. It is intended to present a user-friendly standard method of creating accurate digital skeletal models using Agisoft PhotoScan.

MATERIALS AND METHODS

Approximately 200 photographs were taken of three different crania, and were separated into series consisting of 50, 75, 100, 150, and approximately 200 photos. Forty-five cranial models were created using different photo series and a variety of PhotoScan settings. These models were assessed based on defined qualitative criteria, and model measurement estimates were compared with physical skeletal measurements using Bland-Altman plots.

RESULTS

The majority of all models (37/45) produced measurement estimates with mean differences of 2 mm or less regardless of PhotoScan settings, and therefore demonstrated high levels of agreement with the physical measurements. Models created with 150 photographs and on "high" PhotoScan settings scored the highest in terms of qualitative appearance in the shortest amount of time.

DISCUSSION

In PhotoScan, it is recommended to create cranial models using 150 photographs and "high" settings; this produces digital cranial models that are comparable to physical crania in both appearance and proportion. SfM photogrammetry is a convenient, noninvasive, and rapid 3D modeling tool that can be used in almost any setting to produce digital models, and following the guidelines established here will ensure that these models are metrically accurate.