Plasmonic Surfaces for Cell Growth and Retrieval Triggered by Near‐Infrared Light

Abstract

Methods for efficient detachment of cells avoiding damage are required in tissue engineering and regenerative medicine.W ei ntroduce ab ottom-up approach to build plasmonic substrates using micellar blockc opolymer nanolithography to generate a2 Da rrayo fA us eeds,f ollowed by chemical growth leading to anisotropic nanoparticles.T he resulting plasmonic substrates show ab road plasmon band covering aw ide part of the visible and near-infrared (NIR) spectral ranges.Both human and murine cells were successfully grown on the substrates.Asimple functionalization step of the plasmonic substrates with the cyclic arginylglycylaspartic acid (c-RGD) peptide allowed us to tune the morphology of integrin-richh uman umbilical vein endothelial cells (HUVEC). Subsequent irradiation with aN IR laser led to highly efficient detachmento ft he cells with cell viability confirmed using the MTT assay. We thusp ropose the use of such plasmonic substrates for cell growth and controlled detachment using remote near-IR irradiation, as ag eneral method for cell culture in biomedical applications.

In Situ Shape Control of Thermoplasmonic Gold Nanostars on Oxide Substrates for Hyperthermia-Mediated Cell Detachment

“…Plasmonic heating has previously been utilized to detach cells from planar substrates at time scales of up to ∼1 h. 25 , 26 Our work builds upon these previous developments by applying the in situ growth method we developed to achieve point-and-shoot release of grafted cells with single-cell specificity. The point-and-shoot release triggered by the localized heating demonstrates the plasmonic activity and the continued potential of our system for additional biological applications ( Figure 4 A).…”

“… 41 , 45 To address this limitation, we developed a seed-mediated synthetic method, enabling direct growth of shape-controlled AuNPs uniformly on oxide substrates, based on recent methods utilized to achieve branched structures on surfaces using in situ shape control. 25 , 49 In particular, we modified a previously established batch seed-mediated growth protocol from Pallavicini and co-workers, 50 improving product reproducibility and reducing the impact of secondary nucleation ( i . e ., uncontrolled formation of new nuclei after particle growth has already begun).…”

“…Furthermore, we leverage gradual heating to demonstrate controlled release of cultured cells from substrates with branched thermoplasmonic structures. 25 In our system, we are able to tune both the flow and the laser fluence systematically to control the heating experienced by the cells. Although the laser fluences (11 mJ/cm 2 ) giving Δ T of 10 and 3 °C without and with flow, respectively, are the same, the cooling effects of flow mitigate damage to the cell, enabling cells to remain on the substrate substantially longer.…”

“…Many researchers have integrated plasmonic nanostructures into solid-state systems such as sensors, 20 − 22 cargo delivery platforms, 23 , 24 substrates for light-responsive cell retrieval, 25 , 26 materials for combined cancer cell hyperthermia/chemotherapies, 12 , 27 , 28 and fundamental studies on phenomena resulting from plasmonic heating ( e . g ., bubble generation).…”

“…Our results suggest that this plasmonic-nanostructure-integrated microfluidic platform will offer new solutions for small-molecule sensing, 20 intracellular delivery via poration, 24 , 46 or the targeted retrieval of single cells in adherent cultures, representing a starting point for the development of devices capable of cell capture and targeted, selective light-triggered release. 25 , 26 …”