Currently, the application of peptide nucleic acids is mainly in the field of gene expression, and PNAs are much later to be used in nanotechnology. PNAs have the specific base-pair recognition properties of DNA and the material-like properties of polyamides, which allow relatively simple modification and conjugation of various chemical groups to the peptide backbone. PNAs are capable of sharing the specific molecular recognition through the precise Watson-Crick base pairing, and thus have potential for nanotechnology based on the self-assembly of PNA structures.
Fig 1. Schematic illustrations of the four main approaches to molecular self-assembly using PNA. (Berger, O.; E. Gazit. 2017)
At BOC Sciences, our experts are able to design and synthesize a series of supramolecular assemblies based on nano-PNA with well-organized structures and nanostructure engineering applications by combining the unique structure of DNA with the chemical versatility of peptides.
PNA is able to form PNA amphiphiles with other substances, resulting in lipid-integrated structures, hydrogels or fibrillary assemblies. We have designed the synthesis of different PNA sequences linked to alkanes of different lengths.
We can also couple a specific PNA segment to a peptide sequence to generate nanofibers, and PNA-peptide amphiphiles conjugates can self-assemble into nanofibers and bind to oligonucleotides with high affinity and specificity. These obtained fibers are highly attractive for nucleic acid purification and biosensors.
Single-stranded PNA sequences are formulated into high-density brushes by graft-through polymerization using ring-opening complex polymerization (ROMP) method. PNA-based amphiphilic polymer brushes can be applied for nucleic acid delivery to cells and DNA purification.
Compared to DNA, heterologous double-stranded DNA-PNA has higher stability. Our experts can also insert PNA molecules into a series of self-assembling DNA building blocks to obtain the self-assembly of PNAs into nanoparticles, thereby improving the chemical and thermal stability of DNA.
Both guanine-containing di-PNA assemblies and guanine-PNA monomer spheres display unique optical properties. di-PNA is the shortest PNA building block that can self-organize into an ordered structure, allowing us to obtain self-assembly of guanine-based PNA molecules without other additives.
The co-assembly of PNA with thymidine-like trihedral cyanuric acid allows polyadenine PNA to assemble into fibers. We also present a novel strategy of PNA self-assembly using a small molecule with three thymine-like facets to modify the structure of polyadenine nucleic acid.
Cyanuric acid is added to hepta-adenine PNAs, and the assembly process is monitored by UV spectrum. These micrometer-long fibers can be produced in large quantities and the composition is cheap and non-toxic.
Fig 2. Self-Assembly of PNA-Photosensitizer Conjugates. (Chang, R.; et al. 2020)