Protein Nanotubes-Future of Nanobiotechnology

Nanobiotechnology is that branch of nanotechnology that deals with biological and biochemical applications or uses. The future of technology resides on the vast potential applications of the field of nanotechnology. Nano- systems in biology, the most complex and highly functional nano-scale materials and machines have been invented by nature. Proteins and nucleic acids, and other naturally occurring molecules (polymers) regulate and control biological systems with incredible precision. Recent research has opened up the avenues for the use of protein nanotubes as the intriguing alternative to carbon nanotubes due to its immense biocompatibility and much lesser cytotoxicity. Generation of PNTs are fields for research themselves. Flagellin-based PNTs were synthesised using a FliC-thioredoxin fusion protein, denoted FliTrx. The flagellin subunit FliC has also been utilized as a potential vector for liposome-based drug delivery. [1] T4P are polymers of a single monomeric type IV pilin (PilA) subunit, a protein comprised of a four-stranded antiparallel -sheet wrapped around one end of a long -helix. It was this engineered pilin monomer that was observed to assemble into PNTs. PNTs can be generated using a template-assisted assembly which can provide a means of patterned PNT assembly followed by removal of the template layer resulting in free PNT. Alumina templates or human serum albumin can be used for a layer by layer approach. [1] Several studies highlight the potential applications of PNTs including targeted drug delivery systems, tissue-engineering scaffolds and biosensing devices. Further research is being carried out to characterize the PNTs, and explore its potential use as biosensors and bionanowires. The development of protein-based nanotubes for biologically based nanosystems is receiving increased interest due to their richness in structural diversity, adaptability through protein engineering approaches and inherent biocompatibility.