Selective Adhesive Cell Capture without Molecular Specificity: New Surfaces Exploiting Nanoscopic Polycationic...

Area of Science:

• Biomaterials Engineering
• Cell Biology
• Surface Chemistry

Background:

• Mammalian cell capture often relies on molecular specificity.
• Developing selective cell collectors without molecular targeting is a significant challenge.
• Understanding the physical interactions between cells and surfaces is crucial for advanced cell separation technologies.

Purpose of the Study:

• To explore how non-specific polycationic nanoscale features on a collecting surface control mammalian cell capture kinetics and selectivity.
• To demonstrate key principles for selective collector design using closely related breast cancer cell lines.
• To investigate the role of surface engineering in achieving adhesive discrimination based on physical cell attributes.

Main Methods:

• Utilized silica surfaces functionalized with poly(dimethyl-aminoethylmethacrylate) (pDMAEMA) at pH 7.4.
• Compared the capture of MCF-7 and TMX2-28 (a tamoxifen-selected clone of MCF-7) breast cancer cell lines.
• Analyzed selectivity based on the arrangement and charge concentration of pDMAEMA nanoscopic cationic surface patches.
• Investigated the ionic strength-dependence of cell capture.

Main Results:

• Engineered surfaces with appropriate pDMAEMA concentrations preferentially captured TMX2-28 cells over MCF-7 cells with a selectivity of 2.5.
• Demonstrated that selectivity arises from collector design, including electrostatic interactions and pDMAEMA arrangement.
• Observed ionic strength-dependence of cell capture similar to silica microparticles, suggesting nanoscale contact area differences are key.
• Showcased adhesive discrimination based on physical cell attributes without molecular specificity.

Conclusions:

• Non-specific polycationic nanoscale features can be engineered for selective mammalian cell capture.
• Collector design, including surface charge distribution and polymer arrangement, dictates cell capture selectivity.
• Physical attributes of cells, discernible at the nanoscale, can be exploited for selective cell adhesion and separation.