After many years of research, the founders of PEPperPRINT GmbH succeeded in bringing a procedure to market that had cleared the typical hurdles associated with the production of high-density peptide chips. Peptides are short protein fragments - amino acid chains - which, when immobilised on chips, are useful detection tools in basic research as well as in the biotechnology and pharmaceutical industries.

Examples of application:

• Analysis of antibody and serum profiles, screening of enzyme substrates;
• Screening of diagnostically-relevant peptide libraries;
• Identification and optimisation of "peptidomimetic" drug candidates (peptide-like or peptide-mimicking substances);
• Discovery and detection of biomarkers and high-throughput drug development.

The production of such peptide chips is very time-consuming and associated with high costs. The scientists Dr. Volker Stadler, Dr. Frank Breitling, Dr. Ralf Bischoff and Dr. Thomas Felgenhauer from the German Cancer Research Centre in Heidelberg have solved this problem and founded PEPperPRINT GmbH, based on the development of an innovative, patented laser printing method for the inexpensive production of peptide chips.

The core of the company's invention is "amino acid toner particles": instead of using pigments, peptide constituents, i.e. amino acids, are embedded in solid toner particles. The amino acid toner particles are spotted onto a glass slide using a specific laser printer: conventional colour laser printers have four printing units. As peptides are composed of any of 20 amino acids that occur naturally in proteins (proteinogenic amino acids) the "peptide laser printer" also has 20 printing units. These printing units are arranged in a line and are synchronised. In addition, a linear stage with a mounting allows for the exact and repeated positioning of the solid support in the micrometre range. After a layer of different "amino acid toner particles" has been deposited on a carrier, peptide synthesis is started by melting these particles, followed by routine washing steps. The entire process is repeated as many times as is required to generate peptide arrays with the desired molecular length.

The laser printing method has definite advantages over other competing technologies used to produce peptide arrays:

• 20-fold increase in spot density
• Considerably lower material requirements due to minimal toner consumption
• Very fast speed and flexibility of the digital printing procedure
• 20-fold reduction in the price compared to the cheapest competitor. 

The company's peptide laser printer has already been used to create arrays with ~5,440 (5.5K) freely chosen peptides on conventional slides or libraries of ~156,000 (156K) peptides on slides with a size of 20 x 20 cm². In addition to peptides consisting of the 20 proteinogenic amino acids, the technology is also suitable for producing peptidomimetics (peptide chains containing amino acids that do not naturally occur in proteins), which have a high stability in the body, and are therefore suitable as drug candidates as they will not be broken down by the human metabolism.

A second-generation peptide laser printer is currently being constructed in an EU project; this printer has a higher degree of automation than the first one and can print more than 500,000 peptides per array. This device will be available in spring 2010.

With their discovery, the PEPperPRINT founders have provided proteomics research with a tool that is similar to the development of DNA chips used in genomics research. The production of chips using the peptide laser printer is extremely efficient, both with regard to molecular variety, the speed of peptide syntheses, reproducibility and costs.

The technology was awarded the prestigious prize of the Stifterverband für die Deutsche Wissenschaft in 2008; in 2009, PEPperPRINT GmbH was selected as a “Landmark in the Land of Ideas”, an initiative of the German government and the German Industry Association. Now, the young biotech company has also received the Science4Life Venture Cup together with 30,000 euros for an “excellent business idea in a market segment with a high potential for the future and for the targeted entrepreneurial spirit of an ambitious management team”. The Science4Life Venture Cup is the largest German business plan competition in the life sciences area.

In a paper which attracted a lot of attention, published in the renowned scientific journal "Science", the researchers demonstrated the superiority of their proprietary peptide synthesis technology over their competitors (Science 318, p.1888, 21.12.2007). They achieved a density of 40,000 peptides per cm², which were visualised with epitope-specific antibodies. Such complex peptide arrays can be used for answering important questions arising in the areas of diagnostics and biomedical research, for example, for scanning the humoral immune response against the proteome of a pathogen.

Moreover, PEPperPRINT creates individualised peptide libraries used in cooperative research projects and on the basis of services required for high-throughput biomarker screening and drug development. The company is about to start its first pilot studies in cooperation with biotechnology and pharmaceutical companies and is looking for investors to be able to expand its production capacities.

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