Dip‐pen nanolithography on SiO_x and tissue‐derived substrates: comparison with multiple biological inks

Abstract

There has been extensive interest in the micro and nanoscale manipulation of various substrates in the past few decades. One promising technique is dip-pen nanolithography which has shown the capability to pattern substrates of all forms including, tissue-derived substrates. Patterning of tissue-derived substrates is of particular interest, as it would facilitate studies into controlling cell morphology and cell-substrate interaction. To expand the field into this area both peptides and bioactive collagen-binding peptide-linked biomolecules were patterned to the inner collagenous zone of the Bruch's membrane (BM). Collagen-binding peptide, and extra cellular matrix (ECM) proteins laminin and fibronectin were patterned on the BM and SiO(x). The lithographic protocol was facilitated by Triton X-100 which was used to clean the tissue-derived construct after harvesting. This produced a collagen-exposed BM which was more hydrophilic (contact angle 67 degrees +/-8.49 degrees) surface compared with other cleaning methods but it maintained similar surface roughness (root-mean-square) 80+/-18 nm and collagen exposure. This type of surface can be readily patterned with the chosen inks under lower humidity conditions.

Characterization of Conformational Adsorbate Changes on a Tissue-Derived Substrate Using Fourier Transform Infrared Spectroscopy

“…This creates a thin free-standing substrate for FT-IR without the need to utilize a microtome to produce a thin tissue slice. Atomic force microscopy has previously been used to show that one produces a surface terminated on collagen fibers using this method …”

“…The RPE has been studied for its responses to a variety of substrates and cell-specific factors. Beyond this, the BM has been modified on both tissue-wide and micrometer length scales , with amino acids, peptides, and/or proteins. Many of the published studies have focused on understanding the pathology of the tissue and have explored the refurbishment of the existing tissue with soluble biomolecules .…”

“…Many of the published studies have focused on understanding the pathology of the tissue and have explored the refurbishment of the existing tissue with soluble biomolecules . Modifications to refurbish the tissue have been principally performed on dried tissues with no ideal methodology for adsorbate structural analysis because of the complex nature of the substrate. − On the basis of reviews of the current literature, we have identified the need to examine these structural changes that might occur when biomolecules are adsorbed onto eye tissues such as the BM.…”

Reactions in ultra-small droplets by tip-assisted chemistry

“…119 Moreover, it is a non-destructive technique that can be used on fragile and soft surfaces like polymers, graphene [121][122][123] or living tissues. 99,124,125 Also, direct-write AFMassisted lithography is ideal to be used in fabrication processes of small devices where the last step consists of positioning valuable functional materials on specific areas of a solid support. For instance, our group deposited a diversity of magnetic materials (ferritin-based CoO nanoparticles, Mn 12 single-molecule magnets and Co nanoparticles) on the most sensitive areas (as small as 1 mm 2 ) of superconductive sensors to enhance their sensitivity without damaging any of the components of the devices.…”

A methodology for preparing nanostructured biomolecular interfaces with high enzymatic activity

“…[20][21][22][23][24] For biomedical applications, DPN and PPL have been used in the development of diagnostics, sensing devices [25][26][27] and in tissue engineering. 28,29 These lithography methods have also been harnessed for fundamental studies in cell biology 20,[29][30][31] and biomolecular motors. 26 A key aspect of many of these biological applications is the need for the immobilization of proteins onto the nanolithographically generated features.…”