In genome editing, also known by the name of ‘genome engineering’, DNA is inserted, deleted, modified or replaced in an organism’s genome. The usual approach to editing is through engineered nucleases (‘molecular scissors’) which generate double-strand breaks (DSBs) in the genome at the targeted locations. These DBSs are repaired through nonhomologous end-joining (NHEJ) or homologous recombination (HR). The results are targeted mutations (‘edits’).
Gene editing will find its way into many different applications, most of them still unimagined. There is a lot of creativity involved in imagining new uses – and a lot of ethical concerns and regulation to consider.
Bioprinting, sometimes called “organic printing”, is a particular application of 3D printing (or ‘additive manufacturing’, a set of technologies to build 3D objects by adding layer upon layer of material) that uses polymers or genetically engineered biomaterials to produce tissues and organs, some of them implantable in the human body. The advantage of bioprinting is individual adaptation of the material and fewer side effects, including implant rejection. Given the state of the art, only a few attempts of modest scale have been made to print organs or tissue of comparable complexity in terms of cellular structure.
The number and size of human parts that can be 3D printed – even on the spot – is growing permanently. Some involve “mere” non-living components which can be steered (ears, prosthetic legs), but the possibilities are expanded by different materials usable in different media (e.g. in water). In the longer run, real biomaterials will be used, either through genetic engineering or through cellular components designed in the lab and then integrated into a human body in order to grow there. The 3D-printing of “high-resolution” living tissue “could revolutionize regenerative medicine and allow the reproduction of complex tissue that could replace or repair damaged or severed areas of the body”. According to researchers, one focus in bioprinting is on “designing a high-resolution cell printing platform from relatively inexpensive components; it could be used to produce artificial tissues with appropriate complexity from a range of cells, including stem cells.” Another area of interest is developing new scaffoldings for 3D-printed organic matter which no longer collapse but keep their shape. In the more distant future, the first 3D-printed human organs will be transplanted without rejections, meeting a huge demand from patients waiting for an organ, but also from people who just want to live longer and replace their (somewhat) malfunctioning organs. On the very long terms, “person-on-a-chip” models may generate “complete tissues for implantation, to repair damaged organs with cells from a patient’s own body”.
The typical vaccines deployed against infectious diseases use dead or weakened pathogens or subunits thereof – in the case of cancer vaccines, directly the relevant proteins – to activate the body’s immune system. The latter recognizes the foreign pathogen through the antigens it carries (in some modern vaccines, just the antigen is provided in fact) and hits back on the next encounter. Genomic vaccines, also known as “DNA vaccines”, take a different approach: they inject genes, specifically DNA or RNA that encode for the needed protein, which then cause cells to produce the protein in question. This has many advantages: producing the genes should be easier than manufacturing the proteins (which need entire cell cultures); more proteins can be crammed in a single vaccine; and they can be adapted as the pathogen goes through the mutations we are familiar with from, for example, the annual flu.
The great promise in DNA vaccination is vaccines that are very stable, easy to produce in great quantity, and quite simple to deliver. When genomic vaccines have become the norm, fewer immunizations are needed, as they last longer, cover a wide spectrum of pathogens, and are easily adaptable to new forms as the latter mutate. Last but hardly least, vaccines tackle some or many forms of cancer, raising a prospect of a world where cancer is a tractable problem.