Fibrillar

Fibrillar is an adjective used in science to describe structures composed of or resembling fibrils, which are slender, thread-like elements that can range from nanometers to micrometers in diameter. The term is applied across multiple disciplines to distinguish filamentous, rope-like arrangements from other morphologies.

In biology, fibrillar structures are common in connective tissues and are formed by proteins that assemble into long, rope-like strands. Fibrillar proteins include collagen, which forms fibrils that confer tensile strength to skin, bone, tendons, and other tissues; elastin and fibrillin contribute to elastic fiber networks. Amyloid fibrils are misfolded protein aggregates that can accumulate in tissues and are associated with various diseases. Some fibrils are part of the normal extracellular matrix, providing scaffold and mechanical support.

In microbiology, bacteria can produce extracellular fibrillar structures, such as curli fibers in Escherichia coli and Salmonella, which promote adhesion and biofilm formation. These fibers arise from the assembly of amyloid-like fibrils and play a role in surface attachment and resilience.

In plants and biomaterials, fibrils refer to cellulose and other polymers arranged into fibrous microfibrils that reinforce cell walls, as well as nanofibrils used in composites and nanomaterials research. Fibrillar architectures are a common strategy to enhance mechanical properties and surface interactions.

In materials science, the term fibrillar describes materials composed of fibrous elements or exhibiting fibrillar morphologies. Examples include cellulose nanofibrils, polymeric fibrils, and silica fibrils, which can reinforce matrices and influence mechanical, optical, and transport properties.