Laser‐scanning lithography (LSL) for the soft lithographic patterning of cell‐adhesive self‐assembled monolayers

Abstract

We report the development of laser-scanning lithography (LSL), which employs a laser-scanning confocal microscope to pattern photoresists that can be utilized, for example, in the fabrication of masters for use in soft lithography. This convenient technique provides even exposure across the entire view field and facilitates accurate alignment of successive photoresist exposures. Features on the scale of 3 microm have been achieved to date with a 10x objective (NA 0.45). Virtual masks, instructions for laser irradiation, were drawn using the Region of Interest (ROI) function of a Zeiss LSM 510 microscope. These regions were then exposed to a 458 nm argon laser for 32 micros (0.9 mW/microm(2)). Differential interference contrast (DIC) imaging was utilized with a non-destructive 514 nm argon laser as an immediate quality check of each exposure, to align successive exposures, and to reduce chromatic aberration between imaging and exposure. Developed masters were replica-molded with poly(dimethylsiloxane) (PDMS); these masters were then utilized for microcontact printing of cell-adhesive self-assembled monolayers (SAMs) to demonstrate the utility of this process. Initial studies confirmed that human dermal fibroblast adhesion and spreading were limited to cell-adhesive SAM areas. LSL is a rapid, flexible, and readily available technique that will accelerate master design and preparation; moreover, it can be applied to additional forms of photolithography and photopolymerization for studies in cell biology, biomaterials design and evaluation, materials science, and surface chemistry.

Vascularization of Engineered Tissues: Approaches to Promote Angiogenesis in Biomaterials

“…Images created in a personal computer were projected through LCDP onto photoreactive samples, and EC adhesion was restricted to capillary vessel-like networks patterned onto the substrates [54]. An alternative method of photolithography employing conventional confocal microscope system was recently reported [55,56]. Virtual patterns were generated in a confocal scanning software, and photoreactive substrates including photoresists and PEG hydrogels were exposed to the confocal lasers as outlined by the virtual patterns with micron scale resolution easily achieved.…”

Response of Human Corneal Fibroblasts on Silk Film Surface Patterns

“…Grooves have been introduced usually by lithographic macro- or nanofabrication techniques on synthetic substrates such as glass, [34] metals, [35] poly(dimethylsiloxane) (PDMS), [36] and nondegradable synthetic polymers [16,37] to understand cell behavior on the patterned surfaces, but without consideration of the biological compatibility and direct tissue utility of the substrate.…”

Surface Treatments to Modulate Bioadhesion: A Critical Review

“…Furthermore, this research showed that the introduction of laminin on the micro-patterned substrate gave rise to an enhancement of cell orientation, elongating them further when compared to solely using the micro-patterned surface. Cell orientation and distribution, and how biological adhesion can be affected using lithography techniques, was also confirmed by Miller et al [103]. In addition to cell adhesion modulation, it was also commented that nano-machining with lithography could be applied to cell transfection and drug delivery [93], two areas of extreme in importance within the healthcare industry.…”