Interpenetrating networks of fibrillar and amorphous collagen promote cell spreading and hydrogel stability.

Hydrogels composed of collagen, the most abundant protein in the human body, are widely used as scaffolds for tissue engineering due to their ability to support cellular activity. However, collagen hydrogels with encapsulated cells often experience bulk contraction due to cell-generated forces, and conventional strategies to mitigate this undesired deformation often compromise either the fibrillar microstructure or cytocompatibility of the collagen. To support the spreading of encapsulated cells while preserving the structural integrity of the gels, we present an interpenetrating network (IPN) of two distinct collagen networks with different crosslinking mechanisms and microstructures.

Cancer Organoids as reliable disease models to drive clinical development of novel therapies.

On September 23-24 (2024) the 6th Workshop IRE on Translational Oncology, titled "Cancer Organoids as Reliable Disease Models to Drive Clinical Development of Novel Therapies," took place at the IRCCS Regina Elena Cancer Institute in Rome. This prominent international conference focused on tumor organoids, bringing together leading experts from around the world.A central challenge in precision oncology is modeling the dynamic tumor ecosystem, which encompasses numerous elements that evolve spatially and temporally.

Live Cell Imaging of Human Liver Fibrosis using Hepatic Micro-Organoids.

Due to the limitations of available in vitro systems and animal models, we lack a detailed understanding of the pathogenetic mechanisms and have minimal treatment options for liver fibrosis. Therefore, we engineered a live cell imaging system that assesses fibrosis in a human multi-lineage hepatic organoid in a microwell (i.e.

Cell tumbling enhances stem cell differentiation in hydrogels via nuclear mechanotransduction.

Cells can deform their local niche in three dimensions via whole-cell movements such as spreading, migration or volume expansion. These behaviours, occurring over hours to days, influence long-term cell fates including differentiation. Here we report a whole-cell movement that occurs in sliding hydrogels at the minutes timescale, termed cell tumbling, characterized by three-dimensional cell dynamics and hydrogel deformation elicited by heightened seconds-to-minutes-scale cytoskeletal and nuclear activity.

In Situ UNIversal Orthogonal Network (UNION) Bioink Deposition for Direct Delivery of Corneal Stromal Stem Cells to Corneal Wounds.

The scarcity of human donor corneal graft tissue worldwide available for corneal transplantation necessitates the development of alternative therapeutic strategies for treating patients with corneal blindness. Corneal stromal stem cells (CSSCs) have the potential to address this global shortage by allowing a single donor cornea to treat multiple patients. To directly deliver CSSCs to corneal defects within an engineered biomatrix, we developed a UNIversal Orthogonal Network (UNION) collagen bioink that crosslinks with a bioorthogonal, covalent chemistry.

Interpenetrating networks of fibrillar and amorphous collagen promote cell spreading and hydrogel stability.

Unlabelled: Hydrogels composed of collagen, the most abundant protein in the human body, are widely used as scaffolds for tissue engineering due to their ability to support cellular activity. However, collagen hydrogels with encapsulated cells often experience bulk contraction due to cell-generated forces, and conventional strategies to mitigate this undesired deformation often compromise either the fibrillar microstructure or cytocompatibility of the collagen. To support the spreading of encapsulated cells while preserving the structural integrity of the gels, we present an interpenetrating network (IPN) of two distinct collagen networks with different crosslinking mechanisms and microstructures.

The lysogenic filamentous bacteriophage phage Pf slows mucociliary transport.

is a major pulmonary pathogen causing chronic pulmonary infections in people with cystic fibrosis (CF). The and lysogenic bacteriophage, Pf phage, is abundant in the airways of many people with CF and has been associated with poor outcomes in a cross-sectional cohort study. Previous studies have identified roles for Pf phage in biofilm formation, specifically forming higher-order birefringent, liquid crystals when in contact with other biopolymers in biofilms.

Engineered Protein Hydrogels as Biomimetic Cellular Scaffolds.

The biochemical and biophysical properties of the extracellular matrix (ECM) play a pivotal role in regulating cellular behaviors such as proliferation, migration, and differentiation. Engineered protein-based hydrogels, with highly tunable multifunctional properties, have the potential to replicate key features of the native ECM. Formed by self-assembly or crosslinking, engineered protein-based hydrogels can induce a range of cell behaviors through bioactive and functional domains incorporated into the polymer backbone.

-Forming, Bioorthogonally Cross-linked, Nanocluster-Reinforced Hydrogel for the Regeneration of Corneal Defects.

Corneal defects can lead to stromal scarring and vision loss, which is currently only treatable with a cadaveric corneal transplant. Although -forming hydrogels have been shown to foster regeneration of the cornea in the setting of stromal defects, the cross-linking, biomechanical, and compositional parameters that optimize healing have not yet been established. This, Corneal defects are also almost universally inflamed, and their rapid closure without fibrosis are critical to preserving vision.

Photoactivated growth factor release from bio-orthogonally crosslinked hydrogels for the regeneration of corneal defects.

-forming hydrogels are an attractive option for corneal regeneration, and the delivery of growth factors from such constructs have the potential to improve re-epithelialization and stromal remodeling. However, challenges persist in controlling the release of therapeutic molecules from hydrogels. Here, an -forming bio-orthogonally crosslinked hydrogel containing growth factors tethered photocleavable linkages (PC-HACol hydrogel) was developed to accelerate corneal regeneration.

Engineered matrices reveal stiffness-mediated chemoresistance in patient-derived pancreatic cancer organoids.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by its fibrotic and stiff extracellular matrix. However, how the altered cell/extracellular-matrix signalling contributes to the PDAC tumour phenotype has been difficult to dissect. Here we design and engineer matrices that recapitulate the key hallmarks of the PDAC tumour extracellular matrix to address this knowledge gap.

Air-liquid intestinal cell culture allows rheological characterization of intestinal mucus.

Intestinal health heavily depends on establishing a mucus layer within the gut with physical properties that strike a balance between being sufficiently elastic to keep out harmful pathogens yet viscous enough to flow and turnover the contents being digested. Studies investigating dysfunction of the mucus layer in the intestines are largely confined to animal models, which require invasive procedures to collect the mucus fluid. In this work, we develop a nondestructive method to study intestinal mucus.

Laminin-associated integrins mediate Diffuse Intrinsic Pontine Glioma infiltration and therapy response within a neural assembloid model.

Diffuse Intrinsic Pontine Glioma (DIPG) is a highly aggressive and fatal pediatric brain cancer. One pre-requisite for tumor cells to infiltrate is adhesion to extracellular matrix (ECM) components. However, it remains largely unknown which ECM proteins are critical in enabling DIPG adhesion and migration and which integrin receptors mediate these processes.

Gelation of Uniform Interfacial Diffusant in Embedded 3D Printing.

While the human body has many different examples of perfusable structures with complex geometries, biofabrication methods to replicate this complexity are still lacking. Specifically, the fabrication of self-supporting, branched networks with multiple channel diameters is particularly challenging. Here, we present the Gelation of Uniform Interfacial Diffusant in Embedded 3D Printing (GUIDE-3DP) approach for constructing perfusable networks of interconnected channels with precise control over branching geometries and vessel sizes.

Pf bacteriophages hinder sputum antibiotic diffusion via electrostatic binding.

Despite great progress in the field, chronic () infections remain a major cause of morbidity and mortality in patients with cystic fibrosis, necessitating treatment with inhaled antibiotics. Pf phage is a filamentous bacteriophage produced by that has been reported to act as a structural element in biofilms. Pf presence has been associated with resistance to antibiotics and poor outcomes in cystic fibrosis, though the underlying mechanisms are unclear.

Diffusion-Based 3D Bioprinting Strategies.

3D bioprinting has enabled the fabrication of tissue-mimetic constructs with freeform designs that include living cells. In the development of new bioprinting techniques, the controlled use of diffusion has become an emerging strategy to tailor the properties and geometry of printed constructs. Specifically, the diffusion of molecules with specialized functions, including crosslinkers, catalysts, growth factors, or viscosity-modulating agents, across the interface of printed constructs will directly affect material properties such as microstructure, stiffness, and biochemistry, all of which can impact cell phenotype.

Embedded 3D Bioprinting of Collagen Inks into Microgel Baths to Control Hydrogel Microstructure and Cell Spreading.

Microextrusion-based 3D bioprinting into support baths has emerged as a promising technique to pattern soft biomaterials into complex, macroscopic structures. It is hypothesized that interactions between inks and support baths, which are often composed of granular microgels, can be modulated to control the microscopic structure within these macroscopic-printed constructs. Using printed collagen bioinks crosslinked either through physical self-assembly or bioorthogonal covalent chemistry, it is demonstrated that microscopic porosity is introduced into collagen inks printed into microgel support baths but not bulk gel support baths.

Rapid assessment of changes in phage bioactivity using dynamic light scattering.

Extensive efforts are underway to develop bacteriophages as therapies against antibiotic-resistant bacteria. However, these efforts are confounded by the instability of phage preparations and a lack of suitable tools to assess active phage concentrations over time. In this study, we use dynamic light scattering (DLS) to measure changes in phage physical state in response to environmental factors and time, finding that phages tend to decay and form aggregates and that the degree of aggregation can be used to predict phage bioactivity.

A Library of Elastin-like Proteins with Tunable Matrix Ligands for 3D Neural Cell Culture.

Hydrogels with encapsulated cells have widespread biomedical applications, both as tissue-mimetic 3D cultures and as tissue-engineered therapies . Within these hydrogels, the presentation of cell-instructive extracellular matrix (ECM)-derived ligands and matrix stiffness are critical factors known to influence numerous cell behaviors. While individual ECM biopolymers can be blended together to alter the presentation of cell-instructive ligands, this typically results in hydrogels with a range of mechanical properties.

Cell Microencapsulation Within Engineered Hyaluronan Elastin-Like Protein (HELP) Hydrogels.

Three-dimensional cell encapsulation has rendered itself a staple in the tissue engineering field. Using recombinantly engineered, biopolymer-based hydrogels to encapsulate cells is especially promising due to the enhanced control and tunability it affords. Here, we describe in detail the synthesis of our hyaluronan (i.

Human enteroids as a tool to study conventional and ultra-high dose rate radiation.

Radiation therapy, one of the most effective therapies to treat cancer, is highly toxic to healthy tissue. The delivery of radiation at ultra-high dose rates, FLASH radiation therapy (FLASH), has been shown to maintain therapeutic anti-tumor efficacy while sparing normal tissues compared to conventional dose rate irradiation (CONV). Though promising, these studies have been limited mainly to murine models.

Tunable hydrogel viscoelasticity modulates human neural maturation.

Human-induced pluripotent stem cells (hiPSCs) have emerged as a promising in vitro model system for studying neurodevelopment. However, current models remain limited in their ability to incorporate tunable biomechanical signaling cues imparted by the extracellular matrix (ECM). The native brain ECM is viscoelastic and stress-relaxing, exhibiting a time-dependent response to an applied force.

3D printing microporous scaffolds from modular bioinks containing sacrificial, cell-encapsulating microgels.

Microgel-based biomaterials have inherent porosity and are often extrudable, making them well-suited for 3D bioprinting applications. Cells are commonly introduced into these granular inks post-printing using cell infiltration. However, due to slow cell migration speeds, this strategy struggles to achieve depth-independent cell distributions within thick 3D printed geometries.