Patient-specific prostate tumour growth simulation: a first step towards the digital twin.

Prostate cancer (PCa) is a major world-wide health concern. Current diagnostic methods involve Prostate-Specific Antigen (PSA) blood tests, biopsies, and Magnetic Resonance Imaging (MRI) to assess cancer aggressiveness and guide treatment decisions. MRI aligns with medicine, as patient-specific image biomarkers can be obtained, contributing towards the development of digital twins for clinical practice.

Physico-chemical characterization of the tumour microenvironment of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy that accounts for more than 90% of pancreatic cancer diagnoses. Our research is focused on the physico-chemical properties of the tumour microenvironment (TME), including its tumoural extracellular matrix (tECM), as they may have an important impact on the success of cancer therapies. PDAC xenografts and their decellularized tECM offer a great material source for research in terms of biomimicry with the original human tumour.

In silico assessment of the bone regeneration potential of complex porous scaffolds.

Mechanical environment plays a crucial role in regulating bone regeneration in bone defects. Assessing the mechanobiological behavior of patient-specific orthopedic scaffolds in-silico could help guide optimal scaffold designs, as well as intra- and post-operative strategies to enhance bone regeneration and improve implant longevity. Additively manufactured porous scaffolds, and specifically triply periodic minimal surfaces (TPMS), have shown promising structural properties to act as bone substitutes, yet their ability to induce mechanobiologially-driven bone regeneration has not been elucidated.

The rise of mechanical metamaterials: Auxetic constructs for skin wound healing.

Auxetic materials are known for their unique ability to expand/contract in multiple directions when stretched/compressed. In other words, they exhibit a negative Poisson's ratio, which is usually positive for most of materials. This behavior appears in some biological tissues such as human skin, where it promotes wound healing by providing an enhanced mechanical support and facilitating cell migration.

Collagen-Laponite Nanoclay Hydrogels for Tumor Spheroid Growth.

The extracellular matrix (ECM) plays an important regulatory role in the development and progression of tumoral tissue. Its functions and properties are crucial in determining tumor cell behavior such as invasion, migration, and malignancy development. Our study explores the role of collagen type I in cancer development and spread using engineered tumor models like multicellular spheroids grown in collagen-based hydrogels to simulate early tumor formation.

A bone-on-a-chip collagen hydrogel-based model using pre-differentiated adipose-derived stem cells for personalized bone tissue engineering.

Mesenchymal stem cells have contributed to the continuous progress of tissue engineering and regenerative medicine. Adipose-derived stem cells (ADSC) possess many advantages compared to other origins including easy tissue harvesting, self-renewal potential, and fast population doubling time. As multipotent cells, they can differentiate into osteoblastic cell linages.

Decellularization of tumours: A new frontier in tissue engineering.

Cancer is one of the leading causes of death worldwide. The tumour extracellular matrix (ECM) has unique features in terms of composition and mechanical properties, resulting in a structurally and chemically different ECM to that of native, healthy tissues. This paper reviews to date the efforts into decellularization of tumours, which in the authors' view represents a new frontier in the ever evolving field of tumour tissue engineering.

In Vitro Hydrolytic Degradation of Polyester-Based Scaffolds under Static and Dynamic Conditions in a Customized Perfusion Bioreactor.

Creating biofunctional artificial scaffolds could potentially meet the demand of patients suffering from bone defects without having to rely on donors or autologous transplantation. Three-dimensional (3D) printing has emerged as a promising tool to fabricate, by computer design, biodegradable polymeric scaffolds with high precision and accuracy, using patient-specific anatomical data. Achieving controlled degradation profiles of 3D printed polymeric scaffolds is an essential feature to consider to match them with the tissue regeneration rate.

Biomechanical evaluation of syndesmotic fixation techniques via finite element analysis: Screw vs. suture button.

Background And Objective: Tibiofibular syndesmotic injuries may cause degenerative changes, reduction in ankle function and compromising ankle stability. Different fixation techniques try to restore its functionality. Screw-fixation is the gold-standard.

Multiscale modeling of bone tissue mechanobiology.

Mechanical environment has a crucial role in our organism at the different levels, ranging from cells to tissues and our own organs. This regulatory role is especially relevant for bones, given their importance as load-transmitting elements that allow the movement of our body as well as the protection of vital organs from load impacts. Therefore bone, as living tissue, is continuously adapting its properties, shape and repairing itself, being the mechanical loads one of the main regulatory stimuli that modulate this adaptive behavior.

Mechano-driven regeneration predicts response variations in large animal model based on scaffold implantation site and individual mechano-sensitivity.

It is well founded that the mechanical environment may regulate bone regeneration in orthopedic applications. The purpose of this study is to investigate the mechanical contributions of the scaffold and the host to bone regeneration, in terms of subject specificity, implantation site and sensitivity to the mechanical environment. Using a computational approach to model mechano-driven regeneration, bone ingrowth in porous titanium scaffolds was simulated in the distal femur and proximal tibia of three goats and compared to experimental results.

Automated muscle elongation measurement during reverse shoulder arthroplasty planning.

Background: Adequate deltoid and rotator cuff elongation in reverse shoulder arthroplasty is crucial to maximize postoperative functional outcomes and to avoid complications. Measurements of deltoid and rotator cuff elongation during preoperative planning can support surgeons in selecting a suitable implant design and position. Therefore, this study presented and evaluated a fully automated method for measuring deltoid and rotator cuff elongation.

Primary Human Osteoblasts Cultured in a 3D Microenvironment Create a Unique Representative Model of Their Differentiation Into Osteocytes.

Microengineered systems provide an strategy to explore the variability of individual patient response to tissue engineering products, since they prefer the use of primary cell sources representing the phenotype variability. Traditional systems already showed that primary human osteoblasts embedded in a 3D fibrous collagen matrix differentiate into osteocytes under specific conditions. Here, we hypothesized that translating this environment to the organ-on-a-chip scale creates a minimal functional unit to recapitulate osteoblast maturation toward osteocytes and matrix mineralization.

Integration of cortical thickness data in a statistical shape model of the scapula.

Knowledge about bone morphology and bone quality of the scapula throughout the population is fundamental in the design of shoulder implants. In particular, regions with the best bone stock (cortical bone) are taken into account when planning the supporting screws, aiming for an optimal fixation. As an alternative to manual measurements, statistical shape models (SSMs) have been commonly used to describe shape variability within a population.

Evaluation of Patellar Contact Pressure Changes after Static versus Dynamic Medial Patellofemoral Ligament Reconstructions Using a Finite Element Model.

Objectives: To evaluate the effect of various medial patellofemoral ligament (MPFL) fixation techniques on patellar pressure compared with the native knee.

Methods: A finite element model of the patellofemoral joint consisting of approximately 30,700 nodes and 22,200 elements was created from computed tomography scans of 24 knees with chronic lateral patellar instability. Patellar contact pressures and maximum MPFL graft stress at five positions of flexion (0°, 30°, 60°, 90°, and 120°) were analyzed in three types of MPFL reconstruction (MPFLr): (1) static/anatomic, (2) dynamic, using the adductor magnus tendon (AMT) as the femoral fixation, and (3) dynamic, using the quadriceps tendon as the attachment (medial quadriceps tendon-femoral ligament (MQTFL) reconstruction).

Parametric finite element model of medial patellofemoral ligament reconstruction model development and clinical validation.

Background: Currently, there is uncertainty regarding the long-term outcome of medial patellofemoral ligament reconstructions (MPFLr). Our objectives were: (1) to develop a parametric model of the patellofemoral joint (PFJ) enabling us to simulate different surgical techniques for MPFLr; (2) to determine the negative effects on the PFJ associated with each technique, which could be related to long-term deterioration of the PFJ.

Methods: A finite element model of the PFJ was created based on CT data from 24 knees with chronic lateral patellar instability.

[Hospital admissions into paediatric palliative care: A retrospective study].

Introduction: Patients may be admitted to hospital by paediatric palliative care units (PPCU) for different reasons, due to their different needs and clinical problems. The objective of this study is to present the data of patients admitted to the PPCU of the Autonomous Community of Madrid.

Methods: Descriptive retrospective study was conducted by reviewing the clinical records of the PPCU between January 2011 and December 2016.

Discrete particle model for cement infiltration within open-cell structures: Prevention of osteoporotic fracture.

This paper proposes a discrete particle model based on the random-walk theory for simulating cement infiltration within open-cell structures to prevent osteoporotic proximal femur fractures. Model parameters consider the cement viscosity (high and low) and the desired direction of injection (vertical and diagonal). In vitro and in silico characterizations of augmented open-cell structures validated the computational model and quantified the improved mechanical properties (Young's modulus) of the augmented specimens.

Biomechanical evaluation of tibial bone adaptation after revision total knee arthroplasty: A comparison of different implant systems.

The best methods to manage tibial bone defects following total knee arthroplasty remain under debate. Different fixation systems exist to help surgeons reconstruct knee osseous bone loss (such as tantalum cones, cement, modular metal augments, autografts, allografts and porous metaphyseal sleeves) However, the effects of the various solutions on the long-term outcome remain unknown. In the present work, a bone remodeling mathematical model was used to predict bone remodeling after total knee arthroplasty (TKA) revision.

Clinical Impact of Rapid Intravenous Rehydration With Dextrose Serum in Children With Acute Gastroenteritis.

Objectives: We designed a study to compare rapid intravenous rehydration based on 0.9% normal saline (NS) or on NS + glucose 2.5% serum (SGS 2.

Range of Movement for Impingement and Dislocation Avoidance in Total Hip Replacement Predicted by Finite Element Model.

Dislocation is a serious complication in total hip replacement (THR). An inadequate range of movement (ROM) can lead to impingement of the prosthesis neck on the acetabular cup; furthermore, the initiation of subluxation and dislocation may occur. The objective of this study was to generate a parametric three-dimensional finite element (FE) model capable of predicting the dislocation stability for various positions of the prosthetic head, neck, and cup under various activities.

Lower Low-Density Lipoprotein Cholesterol Levels Are Associated with Severe Dengue Outcome.

Dengue virus (DENV) is a flavivirus of worldwide importance, with approximately 4 billion people across 128 countries at risk of infection, and up to 390 million infections and 96 million clinically apparent cases estimated annually. Previous in vitro studies have shown that lipids and lipoproteins play a role in modifying virus infectivity. However, the relationship between development of severe dengue and total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, is unclear.

In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants.

Interaction between cells and implant surface is crucial for clinical success. This interaction and the associated surface treatment are essential for achieving a fast osseointegration process. Several studies of different topographical or chemical surface modifications have been proposed previously in literature.

A coupled mechano-biochemical model for bone adaptation.

Bone remodelling is a fundamental biological process that controls bone microrepair, adaptation to environmental loads and calcium regulation among other important processes. It is not surprising that bone remodelling has been subject of intensive both experimental and theoretical research. In particular, many mathematical models have been developed in the last decades focusing in particular aspects of this complicated phenomenon where mechanics, biochemistry and cell processes strongly interact.