Simultaneous biochemical and topographical patterning on curved surfaces using biocompatible sacrificial molds

Abstract

A method for the simultaneous (bio)chemical and topographical patterning of enclosed structures in poly(dimethyl siloxane) (PDMS) is presented. The simultaneous chemical and topography transference uses a water-soluble chitosan sacrificial mold to impart a predefined pattern with micrometric accuracy to a PDMS replica. The method is compared to conventional soft-lithography techniques on planar surfaces. Its functionality is demonstrated by the transference of streptavidin directly to the surface of the three-dimensional PDMS structures as well as indirectly using streptavidin-loaded latex nanoparticles. The streptavidin immobilized on the PDMS is tested for bioactivity by coupling with fluorescently labeled biotin. This proves that the streptavidin is immobilized on the PDMS surface, not in the bulk of the polymer, and is therefore accessible for use as signaling/binding element in micro and bioengineering. The use of a biocompatible polymer and processes enables the technique to be used for the chemical patterning of tissue constructions.

Manufacturing of Large‐Scale Functional Objects Using Biodegradable Chitosan Bioplastic

“…For consumer products with many small parts consisting different types and colors of plastics, the resources it requires to separate the plastics far exceed their value, and hence these items are often discarded. By contrast, chitosan can capture and retain small molecules, a property that has been leveraged in the past to develop novel controlled‐release molecular delivery systems . Thus, we employed this property of chitosan to retain and program the controlled release of colorants to avoid the requirement of labor‐intensive color‐based sorting of these bioplastic objects before recycling.…”

Patterning on Topography for Generation of Cell Culture Substrates with Independent Nanoscale Control of Chemical and Topographical Extracellular Matrix Cues

“…To address this, researchers have used multilayer stamps having rigid topographic features coupled to a soft layer so the stamps can conform better to substrate topographies (Odom, Love, Wolfe, Paul, & Whitesides, ; Schmid & Michel, ). The µCP of molecules onto sacrificial substrates, followed by substrate dissolution, has also been used to pattern some topographic substrates (Fernandez, Samitier, & Mills, ; Yu, Xiong, Tay, Leong, & Tan, ). However, these approaches are limited to patterning substrate topographies with low aspect ratio features.…”

Bioinspired Chitinous Material Solutions for Environmental Sustainability and Medicine

“…For this reason, changes of chitosan morphology produced by electrical charge have been studied extensively during the last few years 75. These studies revealed that chitosan undergoes a shape change that correlates directly with the ion concentration of its surroundings (i.e., pH), and this property has been exploited to impart topographical and chemical patterns to 3D chitosan structures for the controlled release of biomolecules 76…”