The new biological 3D printing method is expected to be applied to organ chip and cell therapy.

The dream of 3D-printed living organs is remote, but humans are approaching it.
Professor He Yong of Zhejiang University's School of Mechanical Engineering, the team has invented a new biological 3D printing method that can manipulate different kinds of cells to form microspheres of a particular structure, which in turn grow into bioactive microstructures.
papers were recently published in the journal SMALL as a backcover article.
this method will provide an effective path for in vitro reconstruction of organ-like organs, the development of more efficient organ chips, and the implementation of more effective cell therapy.
"model" a lot, so far can not be implanted if one day, humans are free to make human "parts", the replacement of organs is as convenient as replacing batteries, the source of organ transplants is no longer a problem.
but to really achieve 3D printing of living organs, the road is still a little far away.
in the "early stages" of 3D printing, humans have been able to print relatively simple components such as teeth and bones with precision and apply them to clinical practice.
patients with skull damage can also be reshaped by 3D-printed skull.
the challenge of extending printing targets to all parts of the human body is largely challenged.
first, you have to make sure that artificial organs can adapt to the mechanical environment of the human body, not too hard, too soft or collapsed;
for example, although there are many 3D-printed heart "models", no real 3D-printed heart has been successfully implanted into an organism. "We'll try to see if we can achieve a small goal of printing bioactive microtissues first,"
.
," He yong said.
natural biological tissue is more complex than we think.
such as blood vessels are complex structures consisting of fibroblasts, smooth muscle cells, endothelial cells, etc.
smooth muscle swells blood vessels, and endothelial cells secrete growth factors to prevent blood clotting.
"If you want to 'print' blood vessels, you need to print different cells together to form a specific structure."
," He yong said.
by a stream of air, three years ago, the three-dimensional structure was formed in tiny spaces, the team began to try.
they wrap different cells in water gels into "bio-inks" and, under the control of a microfluidic chip nozzle, "spit" a little bit out of multi-component cell microdrops.
" With this machine, we 'hit' out of the vascular bone tissue.
" He Yong said they first printed spiral-shaped microspheres using two "bio-inks" that mixed bone marrow-to-bone-filling stem cells and human umbilical cord venous endothelial cells.
, bone marrow-to-prosthesis stem cells can be directed into osteoblasts, endothelial cells will form angiogenesis cells.
after a few days of laboratory culture, spiral blood vessels into the bone-like organs formed.
in this way, the lab also made roses, spiral microspheres, tai chi and other shapes of particles, diameter of about 200 microns.
in short, cells can be manipulated to form specific "formations".
one of the "bio-ink" components of hydrogel is known as a "soft" substance, to such a soft material precise control, is a rather difficult challenge.
team with a burst of "wind" cleverly solve this problem: under the blow of a micro-air flow, the droplets spewed out by the nozzle will not fall immediately, but will rotate up, at this time according to mathematical modeling to control the direction of the decline of different components of biological ink, you can form a delicate three-dimensional structure.
this process, a bit like us slothing on a rotating cake mold, allowing different cells to form specific three-dimensional formations.
" the technology can be accurate with single-cell resolution.
" He Yong said that compared with the existing biological manufacturing methods, it is characterized by the first time to achieve the controlled molding of three-dimensional structures in tiny spaces, providing a new way of thinking for the in vitro reconstruction of complex organ-like organs.
is expected to be used in organ chips, cell therapy we can construct active mini-biological tissue for drug screening of organ chips. another use,
, says He Yong, is cell therapy.
one of the difficulties of current cell therapy is that directly injected cells are easily swallowed by their own immune cells and are therefore only effective for certain diseases.
"We may be able to print out cell microspheres with specific functions, cell clumps that travel through blood vessels, are not afraid to be eaten, and can function as soon as we get to the destination."
," He yong said.
a professor of biology at Zhejiang University, the study is medically significant: people are already able to grow various types of cells from stem cells, but then we need to have them formed a specific organizational structure.
"the rich and varied ways of connecting cells and cells in living organisms, they are not a pot of porridge," so how to make cells form different levels, tissues and even organs is a very important topic.
"Source: Science Daily