Coding Macromolecules: Inputting Information in Polymers Using Monomer-Based Alphabets

Abstract

The monomer units of a polymer can be used to encode a message. This property is used, for instance, by nature to store genetic information in DNA macromolecules. Therefore, during the past decades, many researchers have aimed to recreate in vitro or in vivo the properties of nucleic acids. Peptide nucleic acids, or more generally speaking xeno-nucleic acids, are interesting examples of man-made genetic polymers. However, the genetic code is surely not the only type of code that can be "written" in a polymer. In principle, many other monomer-based codes could be developed. For example, a binary code can be potentially implemented in a synthetic macromolecule using two comonomers defined as 0 and 1 bit. This possibility is exciting because it would permit to develop a full new class of synthetic polymers, which contain sequence-coded information. Such polymers could be interesting for a variety of new applications, for example in the field of data storage and product identification. However, these tempting options are currently underexplored. It should be clarified that the development of informationcontaining macromolecules is not trivial. First of all, in order to contain "readable" information, such polymers should possess perfectly controlled comonomer sequences. Moreover, chemical and analytical methods that allow deciphering of sequencecoded information have to be developed. The aim of the present Perspective is to show that significant progress has been done in that direction during the past two years. For instance, convenient strategies have been reported for the preparation of monodisperse sequence-defined macromolecules. In addition, encouraging advances have been made for the sequencing of nonnatural polymers. These recent results are discussed and critically analyzed herein. Altogether, monomer-based information storage should be regarded as a new property of synthetic matter.

A Scalable and High‐Yield Strategy for the Synthesis of Sequence‐Defined Macromolecules

“…[7] Here,h igh yields in each reaction step are crucial in the synthesis of longer sequences.T herefore,s calable synthesis protocols that allow for high overall yields are required in order to bring sequencedefined macromolecules into application, for instance as artificial enzymes,c atalysts,a nd active ingredients for pharmaceutical applications.H owever, some of the envisioned applications of sequence-defined materials,for instance in the field of data storage,d on ot necessarily need larger scales. [8] In order to achieve high yields and scalability with one strategy,a na ppropriate monomer was synthesized and subsequently used for the synthesis of sequence-defined oligomers through iterative Passerini three-component reaction (P-3CR) and deprotection. Thus,amonomer having both an isocyanide and ab enzyl ester protected carboxylic acid function was prepared, which is similar to the monomer employed for the synthesis of dendrimers using the Ugi fourcomponent reaction (Ugi-4CR).…”

A New Class of Materials: Sequence‐Defined Macromolecules and Their Emerging Applications

“…[12,13] Compared to DNA, synthetic polymer chemistry offers a unique opportunity to significantly increase the storage density. It thus appears attractive to exploit sequence-defined macromolecules as a medium for coding and decoding of information at the molecular level.…”

Molecular computing: paths to chemical Turing machines

“…Hence, it might be more useful in the future to switch to synthetic polymers, which can be more easily modulated at the molecular level (both with respect to structural diversity and scalability) by making chemical changes in other solvents than water, which is difficult in the case of DNA. In this connection, it is worth mentioning that the idea of encoding information in any polymer chain composed of more than one type of monomer was reported long ago 47,48. For example, a binary sequence information code can be generated in a synthetic polymer chain by using two different co-monomers, with the resulting chain composition representing strings of ones and zeroes 39.…”