Much of the future technology required for rejuvenation of the old involves repairing or cleaning out small-scale protein structures and components in and around cells. Given this, it is worth keeping an eye on the field of synthetic biology, wherein researchers strive to understand, alter, and recreate the low-level machinery of the cell:
Engineering began as an outgrowth of the craftwork of metallurgical artisans. In a constant quest to improve their handiwork, those craftsmen exhaustively and empirically explored the properties - alone and in combination - of natural materials. Today, there is a parallel progression unfolding in the field of synthetic biology, which encompasses the engineering of biological systems from genetically encoded molecular components. The first decade or so of synthetic biology can be viewed as an artisanal exploration of subcellular material. Much as in the early days of other engineering disciplines, the field's focus has been on identifying the building blocks that may be useful for constructing synthetic biological circuits - and determining the practical rules for connecting them into functional systems.
[One] field that now seems poised to undergo a revolution by the forward engineering of cells is biomedicine. Cells naturally perform therapeutic tasks in the body - immune cells identify and remove pathogens, for example - and unlike drugs or molecules, cells can perform complex functions, such as sensing their environments or proliferating. Indeed, patient-specific immune cells are already being genetically engineered with receptors called chimeric antigen receptors (CARs) that allow them to target and destroy tumors in the body. Synthetic circuits and approaches could be used to further enhance these cancer-fighting functions and/or make these cell-based therapies safer. Similar approaches could be envisioned for endowing cells with sense-and-response capabilities to detect and mediate a number of other dysfunctions and pathologies. Promising opportunities for cell-based therapeutics also include patient-specific stem cells for regenerative medicine and microbiome engineering to treat gastrointestinal diseases.
What's more, all of these exciting efforts are occurring simultaneously with our now unprecedented ability to make modifications to the genomes of cells. Using targeting tools, such as zinc fingers, TALEs, and CRISPR/Cas, researchers can now edit specific genes within a genome with very high precision. For example, we can - and do, in the form of gene therapy - use these tools to inactivate genes known to be involved in disease progression or in pathogen life cycles. We can also use them to introduce synthetic circuits into precise locations within a variety of genomes, including in human cells - a feat that would have been impossible less than a decade ago. We can even think about de novo designing and sculpting of genomes to have desirable properties.