Lecture 17 Flashcards
Q: What does “architecture” mean in biomaterials?
A: It refers to both 2D topography (roughness, alignment) and 3D structure (porosity, compliance) that influence cellular behavior.
Q: Why do aligned fibers reduce foreign body response (FBR)?
A: They mimic natural tissue structure, promoting better integration and less immune reaction.
Q: What are common fiber alignment methods?
A: Electrospinning, crystal growth, peptide self-assembly, directional freeze- drying, and cell-mediated tension.
Q: What is electrospinning used for?
A: Creating mats of random or aligned polymer fibers.
Q: Name three 2D surface patterning techniques.
A: Direct-write, dip-pen nanolithography, microcontact printing.
Q: What is microcontact printing?
A: A stamp-based method to create μm–nm scale patterns on surfaces.
Q: What are the two main methods to add 3D architecture in scaffolds?
A: Direct templating and templating around sacrificial materials.
Q: What role do channels play in scaffolds?
A: Provide contact guidance and promote vascularization.
Q: Why is pore size important in tissue scaffolds?
A: It affects cell migration, nutrient flow, and tissue integration.
Q: How is porosity measured?
A: Liquid displacement or image analysis using the formula φ = V_void / V_total.
Q: What is a porogen?
A: A material (e.g., salt, wax, gas) used to create voids during fabrication, removed afterward to make pores.
Q: What is mask photolithography?
A: A light-based technique using masks to pattern photoresists in hydrogels.
Q: What does multi-photon lithography offer?
A: 3D direct-write structuring with 250 nm resolution, even around living cells.
