Photo and Thermo Dual‐Responsive Copolymer Surfaces for Efficient Cell Capture and Release

Abstract

To overcome the low efficiency of single-responsive smart surfaces, we have constructed a dual-responsive smart surface - poly(spiropyran-co-N-isopropylacrylamide) (poly(SP-co-NiPAAm))-grafted silicon nanowire arrays - by combining photo-responsive SP and thermo-responsive NiPAAm units for enhancing the efficiencies of cancer-cell capture and release. These enhanced efficiencies probably originate from the binary cooperative effect of two responsive building units: NiPAAm units can decrease the steric hindrance between SP units during the isomerization while SP units can facilitate phase transition of NiPAAm units. This study provides a new strategy for designing smart materials and surfaces with efficient responsiveness for biomedical applications.

A Chirality/Light Dual‐Responsive Calixarene‐Functionalized Gold Surface for the Separation of Naproxen Enantiomers

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Chiral and photo-responsive calix [4]arene (trans CAC4) host system that can be adsorbed onto gold surfaces was rationally designed and produced in quantitative yields. Chiral recognition through strong host-guest interaction between trans CAC4 and (R)-naproxen was confirmed by fluorescence titration and 1 H NMR analysis.

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“…[3] Chiral recognition and separation of biologically important molecules have attained greater significance in recent years. However, methods to regulate the recognition and separation of chiral molecule through weak non-covalent bonding interaction are highly important, because they also can be applied for control release of chiral drugs, [4] intelligent microfluids [5] and other biotechnological applications. [6] Supramolecular or non-covalent bonding interaction, such as hydrogen bonding, Van der Waals interaction, ionic interaction and host-guest interaction, can be fine-tuned to create a molecular self-assembly at specific configuration, which can be well utilized for enantioselective recognition and separation.…”

“…[40] Easy functionalization of the upper and lower rims bring the advantage of including the chiral auxiliary into the structure, [41] while functionalization of other macrocyclic host is more difficult. The pre-organized macrocyclic structure of the calix [4]arene molecules also allows the formation of densely packed monolayers on the substrate. [42] These factors provide the advantages to utilize calix [4]arene as superior host systems for our study, [43][44][45] reversible and easy preparation of azobenzene identified as a photo-switchable unit in our design.…”

“…The pre-organized macrocyclic structure of the calix [4]arene molecules also allows the formation of densely packed monolayers on the substrate. [42] These factors provide the advantages to utilize calix [4]arene as superior host systems for our study, [43][44][45] reversible and easy preparation of azobenzene identified as a photo-switchable unit in our design. In order to observe the macroscopic change, chiral host unit need to be mounted on a solid support.…”

“…On considering the structural differences between naproxen isomers, we have designed and synthesized the photoresponsive chiral-azo-calix [4]arene (trans CAC4; Scheme 1 and Supporting Information, Figure S1-S4). Here the chirality of the molecule arises from the (R)-1-phenylethylamine, which recognize chiral molecules through non-covalent interaction.…”