Thermally Stable Honeycomb‐Patterned Porous Films of a Poly(L‐lactic acid) and Poly(D‐lactic acid) Stereo Complex Prepared Using the Breath Figure Technique

Abstract

cells. Scaffolds with pores ranging from subcellular to cellular dimensions are particularly attractive materials for understanding the behavior of cells growing on porous scaffolds. However, porous materials currently available for use as cell culture scaffolds have heterogeneous pores, making it diffi cult to optimize their mass-transfer properties.A honeycomb-patterned polymer fi lm prepared by casting polymer solution under humid conditions, followed by solvent evaporation, holds promise for a wide variety of applications, including as superhydrophobic surfaces, [ 13,14 ] a template composed of microlens arrays, [ 15,16 ] porous electrodes, [ 17 ] and other practical applications. [18][19][20][21] These applications utilize the uniformly sized and hexagonally arranged pores of the fi lms. These pores are generated by evaporative cooling, which leads to water droplets condensing onto the surface of the polymer solution during solvent evaporation. The condensed water droplets act as templates to form porous fi lms with hexagonally arranged pores following complete evaporation fi rst of the solvent, then of the template water droplets. [ 22,23 ] This "breath fi gure" technique allows the formation of unique 3D structured, laterally connected pores that refl ect the shape of the template water droplets.Porous polymer materials prepared from biodegradable polymers have received considerable attention due to their potential as cell culture scaffolds for tissue engineering. Porous materials are generally sterilized by autoclaving prior to use as cell culture scaffolds to avoid unexpected biological infection. However, the melting point of biodegradable polymers is typically lower than the temperature used in autoclave sterilization. Here, the preparation of honeycomb fi lms comprising a poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) stereo complex is described and their thermal stabilities are evaluated. The hierarchic photochemical patterning of PLLA/PDLA stereo complex honeycomb-patterned fi lms by UV-O 3 treatment is also demonstrated.

Porous honeycomb film membranes enhance endothelial barrier integrity in human vascular wall bilayer model compared to standard track‐etched membranes

“…Fujifilm established the proprietary mass production standard operating procedures for HCF, optimizing the process and solution formulation to obtain the desired membrane architecture. The HCF fabrication process was previously described 23 . A polymer solution is cast onto a solid substrate under humid conditions.…”

“…The HCF fabrication process was previously described. 23 A polymer solution is cast onto a solid substrate under humid conditions. Water vapor condenses on the liquid-air interface, generating water droplets.…”

Effect of Pore Size of Honeycomb‐Patterned Polymer Film on Spontaneous Formation of 2D Micronetworks by Coculture of Human Umbilical Vein Endothelial Cells and Mesenchymal Stem Cells

“…HCFs were fabricated using an experimental apparatus and a method described in a previous report. [ 43 ] The pore size was controlled by changing the total solid concentration of the polymer solution. The structure of the HCFs was observed using a confocal laser scanning microscope (VKX‐100; Keyence Corporation, Osaka, Japan) and a scanning electron microscope (FE‐SEM; S‐5200, Hitachi High Tech Corp., Tokyo, Japan).…”

Hydrophilic and hydrophobic poly(l‐lactic acid) films by building porous topological surfaces

“…The PLLA films with topological surfaces and adjustable hydrophylic/hydrophobic properties have potential applications in templating, cell culture, microfluidic devices, etc. However, to our knowledge, the reports about PLLA porous films with porous topological surfaces are insufficient …”