Redox probe transport through supported lipid bilayers and nanopore‐confined lipid assemblies on silica thin films is examined using electrochemical impedance spectroscopy (EIS). These supported lipid systems are emerging biomimetic separation and sensor platforms. The ability to quantify the accessibility of the pore structure of the mesoporous silica thin films is demonstrated, which is essential for the incorporation of carriers into the lipids for selective solute transport. Redox probe molecules with varying hydrophilicity are used to compare ion transport in supported lipid pore‐spanning bilayers (enveloped bilayers) and novel lipid filled pores of mesoporous silica thin films. The films feature orthogonally oriented 8–10 nm cylindrical nanopores formed by deposition of P123‐templated silica sols onto chemically modified fluorine‐doped tin oxide. Nanopore accessibility is confirmed by EIS with hydrophilic probe 1,1′‐ferrocenedimethanol (FDM). Filling the pores with lipid 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine results in a superior barrier (with roughly 1/9 the permeability) to transport of FDM compared to fragile enveloped lipid bilayers deposited by vesicle fusion. The pore‐confined lipids not only provide a better barrier to FDM, but also a better pathway for the transport across the films of a hydrophobic redox probe 1,1′‐dioctadecyl‐4,4′‐bipyridinium dibromide, with an ideal transport selectivity of 11 compared to FDM.
Biomaterial properties that modulate T cell activation, growth, and differentiation are of significant interest in the field of cellular immunotherapy manufacturing. In this work, a new platform technology that allows for the modulation of various activation particle design parameters important for polyclonal T cell activation is presented. Artificial antigen presenting cells (aAPCs) are successfully created using supported lipid bilayers on various cell‐templated silica microparticles with defined membrane fluidity and stimulating antibody density. This panel of aAPCs is used to probe the importance of activation particle shape, size, membrane fluidity, and stimulation antibody density on T cell outgrowth and differentiation. All aAPC formulations are able to stimulate T cell growth, and preferentially promote CD8+T cell growth over CD4+T cell growth when compared to commercially available pendant antibody‐conjugated particles. T cells cultured with HeLa‐ and red blood cell–templated aAPCs have a less‐differentiated and less‐exhausted phenotype than those cultured with spherical aAPCs with matched membrane coatings when cultured for 14 days. These results support continued exploration of silica‐supported lipid bilayers as an aAPC platform.
more » « less- PAR ID:
- 10462201
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Healthcare Materials
- Volume:
- 8
- Issue:
- 2
- ISSN:
- 2192-2640
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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