Micropatterning: Interdigitated Multicolored Bioink Micropatterns by Multiplexed Polymer Pen Lithography (Small 19/2013)

Abstract

The cover picture shows that chemical and biological knowledge need to be linked more to ensure that highly effective and target‐specific drugs can be found more quickly. Additionally, the main and side effects must be controlled in the best interests of the individual patient. Despite the intensive use of high‐throughput technologies in drug research, despite new insight in genomic and proteomic research and in structural biology, and despite the progress made in bio‐ and chemoinformatics, there is still a worldwide shortage of new and innovative drugs. The bottleneck in lead‐structure generation lies in the preparation of new biologically relevant substances and therefore to a major extent in chemistry. The way medicinal chemists perceive their subject and its role in the natural sciences as well as in the value chain of drug research is crucial to counteract this shortage, as explained by Wess et al. on page 3341–3350.

Development of Dip‐Pen Nanolithography (DPN) and Its Derivatives

“…Timeline of major milestones in DPN research. DPN has gone through a remarkable evolution from a single tip to parallel tip array and also extended several cantilever‐based (E‐DPN, tDPN, and DNL) and cantilever‐free DPN derivatives (PPL, HSL, and BPL). As a sub‐branch of the cantilever‐free category, BPL opened up the way for photochemistry as additional lithographic option for PPL.…”

“…When switching from the single tip to high‐density massive tip array in cantilever‐based DPN, multiplexed ink delivery to particular tips via microfluidic networks becomes either prohibitively complex or only groups of tips can be addressed . Alternatives put forward so far includes the use of ink‐jet filled PPL stamp molds as ink pad or altering the printing strategy to the use of segmented stamps carrying the different desired inks . Another strategy for multiplexing of PPL is to individually actuate each pen of a PPL pen array.…”

Evaluation of Microfluidic Ceiling Designs for the Capture of Circulating Tumor Cells on a Microarray Platform

“…The microarray within the microfluidic channel was printed via polymer pen lithography (PPL) . This technique combines aspects of microcontact printing and dip‐pen nanolithography (DPN) in a hybrid way and allows large area (several cm²) patterning, especially for sensitive, bioactive molecules in gradients and in a multiplexed fashion . This allows also easy integration into microfluidic systems as we demonstrated for the above‐mentioned application of CTC capture and mast cell screening, recently.…”

Polymer Pen Lithography-Fabricated DNA Arrays for Highly Sensitive and Selective Detection of Unamplified Ganoderma Boninense DNA

“…However, these large “two-dimensional” DPN probe arrays are technically difficult to produce and delicate to use. To address these limitations, polymer pen lithography (PPL) was developed [10,11]. Instead of the cantilevered arrays of stiff probes used in DPN, PPL employs arrays of pyramidal probes consisting of silicone elastomer that are robust and inexpensive.…”