On-Demand Photodegradable and Thermo-Reversible, Soft, Transparent Dithioacetal Hydrogels.

Stimuli-reversible, chemically cross-linked polymers capable of altering their physicochemical and mechanical properties on demand, upon application of external stimuli (e.g., light, temperature), are highly desirable for the development of multifunctional materials.

A 3D SVZonChip Model for In Vitro Mimicry of the Subventricular Zone Neural Stem Cell Niche.

Neural stem cells (NSCs) are crucial components of the nervous system, primarily located in the subventricular zone (SVZ) and subgranular zone (SGZ). The SVZ neural stem cell niche (NSCN) is a specialized microenvironment where growth factors and extracellular matrix (ECM) components collaborate to regulate NSC self-renewal and differentiation. Despite its importance, our understanding of the SVZ remains incomplete due to the inherent challenges of animal research, particularly given the tissue's dynamic nature.

Extrusion-Based 3D Bioprinted Gellan Gum/Poly(vinyl alcohol)/Nano-Hydroxyapatite Composite Bioinks Promote Bone Regeneration.

3D bioprinting is a versatile technology using bioinks comprising living cells mixed with biomaterials and biomolecules to biofabricate structures with precise spatial hierarchy. Based on this principle, novel 3D bioprinted constructs are designed, comprising the natural anionic polysaccharide gellan gum (GG), the synthetic polymer poly(vinyl alcohol) (PVA), and pre-osteoblastic cells. Moreover, nano-hydroxyapatite (nHA) is included to the GG/PVA blend as an osteoinductive biomaterial.

High-Pressure Effects on Gelatin Sol-Gel Transition.

We investigated the effects of high hydrostatic pressure on the sol-gel transition of gelatin dispersions. We used dynamic light scattering (DLS) and DLS-based passive microrheology to monitor the evolution of the viscoelasticity during isothermal gelation. It provided easy identification of the sol-gel transition and the isothermal critical gelation time ( ) and values of viscosities of sols and shear modulus of gels.

Internal Microstructure Dictates Yielding and Flow of Jammed Suspensions and Emulsions.

We propose a microstructural classification of jammed suspensions made of soft, deformable colloids with purely repulsive interactions. Three distinct classes of particles are identified, depending on their ability to accommodate topological constraints upon increasing concentration: emulsions with constant particle volume, noninterpenetrating microgels (without dangling ends), which deswell osmotically, and star polymers, which deswell and interpenetrate. Each class has a specific rheological response in transient and steady-state flows.