I'm pretty darn qualified, (PhD Microbiology, work on gene therapies and vaccines, looked at synthetic methods for treating cancer, have a design for treating HIV/AIDS that gets rid of drugs). I studied virus structure, subunit assembly, and modifications to viruses to express new antigens in an EM lab. I developed an advanced course in biological weapons.

It is simply impossible to print out a virus by 3d methods. You can ferment a virus capsid subunits in E. coli (use a LacZ system, for instance), create a solution or slurry, put it in a printer tank, print them out, and if there is enough water, they will self-assemble. But they will self-assemble better in the holding tank of your printer before you print them out. That is old stuff. It's how virus-like-particles are made. Virus subunits just assemble on their own because they have to or the virus won't be viable.
Can you print out DNA pieces and pile them up on each other on a surface? Yes. Is that printing a virus? No.
Can you synthesize DNA strands to order by 3D printing? Not a chance. The best systems for that were invented by the founders of Blue Heron Biosciences. I know how that technology works. Anyone suggesting that a 3d printer is going to accomplish that is not credible.
Can you put a slurry of viruses in a 3D printer and print them out? Sure. Is that an advance? No. That's hype, because the viruses are created elsewhere. Can he design viruses to fight cancer as he says? No. He can't. Not like that.

What he can do is identify receptors or over-expressed proteins/glycoproteins on the surface of a specific type of cancer. Then, using a set of lab techniques, he can generate (or find in literature) moieties that will bind to those receptors/over-expressed proteins. He can genetically engineer those sequences onto the binding proteins on the surface of a virus and order those sequences synthesized for $0.05-$0.15 per nucleotide. I could go into more detail of other methods for using molecular biology to do this. But! That technique has a problem. Receptors on the surface of cells (or identifying peptides) are generally shared with cells that are not cancerous. So you tend to kill those cells too. Sometimes it can work ok. There are a few such therapies that have gone to clinical trial.

Antibodies work better as a general approach. This is probably because when antibodies bind, they don't entirely bind permanently, and bound antibody will tend to wind up inside the cell it is bound to. So it is likely that normal cells with small numbers of some flag protein the cancer over-expresses can tolerate some antibodies binding. But the cancer cells have tons of them binding. There is a company that used to be in Vacaville. They produced antibodies specific to a particular patient's lymphoma. Then, using molecular biology, they expressed those antibodies in a tobacco mosaic virus. (That is the same method that ZMapp uses to produce its anti-Ebola antibodies.) Those antibodies were harvested from the tobacco leaves and injected into patients. The system worked very well. It saved lives. The company went bankrupt because: Spending was out of control from a set of research scientists who spent money on new research they wanted to do--treating the investor's and grant money like an NIH grant. They were impossible to manage, and uninterested in the prosaic product that was produced to sell. So the investors stopped putting money into it and it crashed and got sold off. This could all be resurrected by someone who wants to save lives and make customized cancer treatments.

Whatever Hessel is doing or trying to do, it isn't what is represented in that press release. What's written there is not credible.