Aptamer‐Modified Nanohydrogel Microarrays for Bioselective Cancer Cell Immobilization

Abstract

Abstract Photolithography combined with surface nucleated protein self‐assembly of azido‐modified spider silk proteins is used to create an arbitrarily shaped, inherently cell repellent micropattern based on nanofibrillar networks. Using “click” chemistry with dibenzocyclooctin modified oligonucleotides, the microstructures are functionalized with DNA‐aptamers, which selectively bind cancer cell markers protein tyrosine kinase 7 or nucleolin. The epitope‐specific cell interaction on the aptamer‐modified surfaces is tested using human non‐adherend leukemia T cells (Jurkat), as well as adherent cervix carcinoma (HeLa) and neuroblastoma (Kelly) cells. The cells can be immobilized with high precision and cell densities on the pattern, also revealing spatially defined proliferation and spreading into distinct morphologies upon cultivation. The formation of integrin‐based focal adhesions occurs in the case of the aptamer immobilized cancer cells, similarly to those anchored on RGD‐modified pattern. The firm aptamer‐marker anchorage allows for the formation of integrin‐dependent cell adhesions. Due to the amenability of the recombinant spider silk protein towards chemical and genetical modifications, the presented micropatterned fibrous networks have great potential for further development of adjustable and biocompatible cell‐specific arrays, enabling applications in circulating cancer cell isolation and cultivation, studies on the cell's pathogenesis, progression and metastasis capabilities as well as enabling development of platforms for personalized medicine.