Chemolabile cellular microarrays for screening small molecules and peptides

Area of Science:

• Biotechnology
• Cell Biology
• Materials Science

Background:

• Developing targeted delivery systems for small molecules into living cells is crucial for research and therapeutics.
• Existing methods often lack spatial control or efficiency in cellular uptake.

Purpose of the Study:

• To create functionalized microarrays that mediate localized uptake of small molecules into tissue culture cells.
• To investigate different immobilization strategies and linker chemistries for controlled substance release.

Main Methods:

• Tissue culture cells were cultured on glass substrates locally functionalized with fluorescently labeled test substances.
• Substances were immobilized via non-covalent interactions or chemolabile linker groups, including various ester linkages.
• Covalent immobilization utilized maleimide-functionalized glass cover slips; non-covalent immobilization was on glass and hydrogel matrices.
• Confocal laser scanning microscopy assessed surface functionalization and release kinetics; cell-penetrating peptides were used to enhance uptake.

Main Results:

• Chemolabile linker groups, particularly phenolic tyrosine esters, facilitated rapid release of immobilized compounds.
• Peptides N-terminally extended with cell-penetrating peptides showed enhanced and localized cellular uptake.
• Uptake was confined to functionalized spots and specific to peptides with cell-penetrating extensions.

Conclusions:

• Functionalized microarrays enable controlled, localized delivery of small molecules and peptides into cells.
• The choice of immobilization strategy and linker chemistry significantly impacts release kinetics and cellular uptake efficiency.
• Cell-penetrating peptide extensions are effective for enhancing targeted cellular delivery via these microarrays.