The Marriage of Biology and Engineering

Bioengineering’s most visible branch is the development of medical innovations such as prosthetics and high-tech implants, but genetic, stem cell and tissue engineering are all set to become key fields in the medicine of the future.

For example, to help prep a surgeon who needed to close the hole in an infant’s heart, a biomedical robotic expert at the Children’s National Medical Centre in Washington, DC created a model heart with a 3D printer. He used a mix of hard and soft plastics to replica the feel of a real heart.

A model heart created by 3D printer Photo: Carolyn Cochenour/Washington Post

In China medical doctors at the Orthopedic Hospital in Zhengzhou City created a 3D model of a dislocated spine. This allowed them to practice a complicated surgical procedure ahead of time…isolating and opening the problem area, resetting the dislocation and then screwing everything back together without damaging the patient’s actual spinal cord.


Model of a spine with a 3D-printed vertebra devise in Beijing Photograph: Jason Lee/Reuters

To rescue babies born with congenital breathing condition which caused their airways to collapse, the University of Michigan has customized tracheal splints made from biocompatible material.   The splints support the collapsed trachea and then get reabsorbed within two years.

Trachea splints Photo courtesy of Leisa Thompson, Photography/UNHA

Using bioengineering to create organ structures that function and restore the health of that tissue for that person, is the holy grail of bioengineering for regenerative medicine.

Scientists at Northwestern University created prosthetic ovaries for mice. The prosthetic ovaries were printed using liquid gelatin made from broken-down collagen, a natural material, which is found in ligaments, tendons, muscles, bones and skin.

A scaffold for a bioprosthetic mouse ovary 3D-printed with gelatin Photo by Kristin Samuelson

The research team built the ovaries by printing various patterns of overlapping gelatin filaments on glass slides—like building with Lincoln Logs, but on a miniature scale: Each scaffold measured just 15 by 15 millimeters. They then carefully inserted mouse follicles—spherical structures containing a growing egg surrounded by hormone-producing cells—into these “scaffolds.”

After punching out 2-millimeter circles through the scaffolds and implanting 40–50 follicles into each one, they created a “bioprosthetic” ovary. The team showed that blood vessels from each mouse infiltrated the scaffolds. This process is critical because it provides oxygen and nutrients to the follicles and allows hormones produced by the follicles to circulate in the blood stream. The result was a fully functional bio-prosthetic ovary that not only restored hormone function, but also allowed the mice to get pregnant, deliver pups and lactate after birth.

In the future ready-to-implant organs should be possible in humans with 3D bioprinting. Scientists are excited that this technique could restore function in cancer patients who have lost their fertility.

Bioengineering is also being used to build artificial biological systems for research, engineering and medical applications.

Illustration of synthetic biology by Eric Proctor and Autumn Kulaga

Synthetic biology gives scientists unprecedented control of living cells at the genetic level. This field encompasses both plant and mammalian cells.

MIT biological engineers have created a programming language that allows them to rapidly design complex, DNA-encoded circuits to give new functions to living cells. The circuit runs inside a bacteria cell.   It’s like they are hacking living cells to program a new language.

Illustration of programing bacteria Image by Janet Iwasa

The MIT team plans to work on several different applications using this approach: bacteria that can be swallowed to aid in digestion of lactose; bacteria that can live on plant roots and produce insecticide if they sense the plant is under attack; and yeast that can be engineered to shut off when they are producing too many toxic byproducts in a fermentation reactor. In the future the bacteria could be programmed to release cancer drugs when encountering a tumor.

Biomedical engineering and biological programming are exciting, expanding new field of research with unlimited possibilities.

 

 

 

Cute but Deadly

Head-on view of caterpillar Credit: Melvyn Yeo/Science Photo Library

Most caterpillars have long hair called setae covering their bodies.  This hair act as a  defense mechanism.  The hairs often have detachable tips that will irritate would-be predators by lodging in the skin or mucous membranes.

Here are a trio to avoid: the puss caterpillar, the hickory tussock caterpillar and the io moth caterpillar.

The most venomous caterpillar in the United States, the puss caterpillar, got its name because it resembles a cuddly house cat. Small, extremely toxic spines stick in your skin releasing venom. At first the sting feels like a bee sting, only worse. The pain rapidly gets worse and can even make your bones hurt. People who have been stung on the hand say the pain can radiate up to their shoulder and last for up to 12 hours.

Furry puss caterpillar feeding. Photo by Caterpillar hunter/Flickr

One dapper critter called the hickory tussock caterpillar has a velvety back and sweeping bristles.  It looks more like a vintage feather boa than a caterpillar and is widely distributed in the eastern half of North America.

Hickory tussock caterpillar Photo by Greg Dwyer/Wikipeida Commons.

Some people have little to no reaction to the hickory tussock’s sting, but others have a reaction that ranges from a mild to severe rash comparable to poison ivy.   It’s microscopic barbs may cause serious medial complications if they are transferred from the hands to the eyes.   The adult moth flies away in May and June.

Caterpillars have to eat a lot. Within a few weeks of devouring as much greenery as physically possible, an io caterpillar can go from being a half-inch-long worm to a nearly three-inch-long monstrosity, brilliant green with red and white racing stripes  like the Io mother caterpillar:

Io moth caterpillar. Photo by Tim Lethbridge

Io caterpillars are indeed capable, and more than willing, to deliver a painful sting. If you brush up against these spines, the tips will break off and start to inject venom.

So what do you do if you get stung by any of these toxic caterpillars? Place Scotch tape over the affected area and strip off repeatedly to remove spines. Apply ice packs to reduce the stinging sensation, and follow with a paste of baking soda and water. If you have a history of hay fever, asthma or allergy, or if allergic reactions develop, contact a physician immediately.

 

 

 

 

 

 

Home is Where the Microbes Are

A person’s home is their castle and they populate it with their own subjects – millions and millions of bacteria.

When we move from one location to another we take all of our bacteria with us and “colonize” the space around us within a matter of hours. These “bacterial signatures” are unique.

Mouth microbes Credit Martin Oeggerli, with support from School of Life Sciences, FHNW

Microbiome studies could serve as a forensic tool. In the future scientists could look at bacterial colonies to identify the last person to come into contact with the victim of a crime and estimated when the contact happened.

Microbes on small intestines Credit: Stephanie Schuller

The human gut teems with bacteria, many of their species still unknown. They help us digest food and absorb nutrients, and they play a part in protecting our intestinal walls. Gut bacteria may also help regulate weight and ward off autoimmune diseases.

Chain of streptococcus in a lab sample. Credit: Photo by Martin Oeggerli, with support from School of Life Sciences, FHNW
Colored scanning electron micrograph of microbes in human gut Photo by Martin Oeggerli

What are “superbugs” ? Any bacteria that cannot be treated by two or more antibiotics is being called a superbug. The CDC claims the single leading factor for the increase in superbugs is the misuse of antibiotics. Most people who get a C. diff (Clostridium difficile) infection are getting medical care.

SEM by David Phillips of Clostridium Difficile

MRSA (Staphylococcus aureus) is carried by around 30 per cent of the population without causing any symptoms. However, in vulnerable people, such as those that have recently had surgery, it can cause wound infections, pneumonia and blood poisoning. MRSA cannot be treated with penicillin.

Staphylococcus aureus MRSA bacteria, computer artwork by Alfred Pasieka/Science Photo Library

Doctors sometimes recommend beneficial bacteria, also known as probiotics, for patients suffering from GI illnesses such as colitis and Crohn’s disease. However, these over-the-counter probiotic supplements may contain varying amounts of bacteria, and may include cells that are no longer viable. Furthermore, these probiotics have no protective coating, so they can be damaged by acid in the stomach before reaching the intestines.

An MIT team has come up with a method of coating these beneficial bacteria with layer-by-layer layers of polysaccharides or sugars. The thin, gel-like coating protects the bacteria cells from acid in the stomach, as well as bile salts. Once the cells reach the intestines, they settle in and begin replicating, creating a whole new microbiome.

MIT coated probiotic bacteria Credit: Second Bay Studios

 

 

Psychedelic Images in Science

3D Computed Tomography (CT) is a nondestructive scanning technology that allows you to view and inspect the external and internal structures of an object in 3D space. Computed Tomography works by taking hundreds or thousands of 2D Digital Radiography projections around a 360 degree rotation of an object. Algorithms are then used to reconstruct the 2D projections into a 3D CT volume, which will allow you to view and slice the part at any angle.

North Star Technology integrated circuit micro Chip 3D x ray nanotanomography ct scan
Integrated circuit micro chip shown using 3D nano tomography CT scan by North Star Technology

The same technology allows medical doctors and dentists to more accurately diagnose their patients and/or to view implants.

Brain Skull DawidKasza istockphoto 185555045
3D CT scan showing brain in human skull Credit:  DawidKasza/iStockphoto.com
Dental-CT-Scan showing implants
Dental 3D CT scan showing dental implants

In the course of developing sophisticated imaging techniques for peering into the human body, radiologist Dr. Kai-Hung Fung discovered something within himself: an artist.

Dr. Fung is a specialist in diagnostic radiology at Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China. The discovery happened when Fung was asked by surgeons to generate 3-D images to allow them to visualize complex anatomies prior to surgery. Beginning with CT scans that show slices of organs at different depths, Fung stacked the slices into a single image and developed a way to indicate changes in depth with contour lines similar to those on a topographic map.

Teeth
Looking at human teeth upward from inside the mouth.  Credit:  Dr. Kai-Hung Fung
Kai Hung Fung CT scan cancerskulll
CT scan of human skull.  The red ring-like pattern is cancer of the thyroid, which has become detached and deposited on the skull bone.  Credit:  Dr. Kai-Hung Fung
Down through top of brain netwk arteries and veins Kai hung Fung blob1
Network of blood vessels inside the brain with the skull base as background.  Credit:  Dr. Kai-Hung Fung

Dr. Fung has used a post-production trick he developed, known as the “rainbow technique” to add colored contour lines to his images. This enhances the 3D effect.

Roof of 4th ventricle of brain K H Fung 1.jpg.CROP.original-original.jpg
Roof of 4th ventricle of brain  Credit:  Dr. Kai-Hung Fung

His approach to radiology doesn’t stop with medical imagery. He has partnered with Dr. Gary Yeoh to produce 3-D CT images of flowers and biological specimens.

Bell pepper (Capsicum annuum), 3D CT scan
Colored 3D CT scan of bell pepper.  Credit:  Dr. Kai-Hung Fung
Whelk, 3D CT scan
Colored 3D CT of whelk shell  Credit:  Dr. Kai-Hung Fung
Stargazer lily from mysicalgarden.org
Stargazer lily from mysticalgarden.org

Dr. Fung’s art career has blossomed. His amazing diagnostic images have been awarded, exhibited and published. His CT and MR scans are more than just psychedelic images, they are “4-D visualizations” that help surgeons visualize the changing perspectives and relative relationships of various anatomical structures.

Check out My Mating Dance

No larger than a ladybug but with an elaborate mating dance the Maratus “peacock” jumping spider of Australia has a spectacular display.

Pair of Australian Maratus "peacock" jumping spiders on human finger. Photo by Jürgen Otto
Pair of Australian Maratus “peacock” jumping spiders on human finger. Photo by Jürgen Otto

To woo the female spiders the males are talented dancer with fancy footwork and an elaborate, decorative abdomen flap that they can raise up and down.

The female watches enthralled and if she is swept away by his magnificence she will allow him to mate, sometimes after first turning and doing her own dance to him, wiggling her abdomen seductively.

The greatest attribute of these jumping spiders is their advanced eyes.  All spiders have eight, occasionally six, eyes, but they are generally quite simple organs, specks of black or silver that can detect light and dark, shadow and movement and some fairly rudimentary blurry images.  The two central front eyes of the jumping spider are much more advanced – large, fronted by spherical lenses, with an internal focussing mechanism and complex four layered retina.  All this means that a jumping spider can see fine detail, in color and at different distances.

Both sexes of the Australian “peacock” jumping spider have the ability to see color through ultraviolet, blue, green and red photoreceptor cells within their eyes.

Close-up of the male Australian Maratus "peacock" jumping spider's color display. Photo by Jürgen Otto
Close-up of the male Australian Maratus “peacock” jumping spider’s color display. Photo by Jürgen Otto

The pattern on the male abdomen is unique and so is the choreography of each species’ dance

A different display on a male Australian Maratus "peacock" jumping spider. Photo by Jürgen Otto
A different display on a male Australian Maratus “peacock” jumping spider. Photo by Jürgen Otto

In June of 2016 Seven new species of peacock spider from the southern coast of Western and South Australia were discovered and named last month, bringing the total number of species discovered up to 48.

A specimen of the newly-discovered Australian Peacock spider, Maratus Bubo, shows off his colourful abdomen in this undated picture from Australia. Jurgen Otto/Reuters
A specimen of the newly-discovered Australian Peacock spider, Maratus Bubo, shows off his colourful abdomen in this undated picture from Australia.    Credit:  Jurgen Otto/Reuters

Just for fun watch this video created by naturalist Jürgen Otto of a male waving his legs around and raising his bright colorful display to attract a nearby female:

 

 

 

 

 

 

 

 

 

Springtails

Springtails, or Collembola, are primitive hexapods (six-legged arthropods) that are closely related to insects. These small critters (usually less than 3 mm) live in soil, leaf litter, and other damp organic material. The name “springtail” comes from an ability to spring forward, or jump, by releasing an appendage that is normally tucked under the abdomen.

There are Springtails in many sizes. There are small ones little more than 0.1 mm, and large ones; the largest species is 17 mm.

Every now and then you’re in luck, as in the photo below taken by Jan J. van Duinen. All of a sudden there are two species of springtails in front of your lens, both adults but very different in size. A big Dicyrtoma fusca and a small Sminthurinus aureus.

Photo by Jan J van Duinen
Photo by Jan J van Duinen

Springtails are ridiculously colorful, quite unexpected for an animal that’s only 1mm big.

Dicyrtomina ornata (c) Andy Chaos
Dicyrtomina ornata found in UK © Andy Chaos

 

Sminthurus viridis Credit: www.aquaportail-com
Sminthurus viridis Credit: http://www.aquaportail-com
 Acanthanura springtail found in Australia with complimentary colors © InvertoPhiles
Acanthanura springtail found in Australia with complimentary colors © InvertoPhiles
 Dicyrtomina ornata Credit: Jan J van Duinen

Dicyrtomina ornata Credit: Jan J van Duinen

Springtails also have interesting courting dances. Perhaps the most fascinating of these behaviors, called the “Cha-Cha-Cha”, involves males and females engaging in a courtship dance with the male and the female initially standing facing each other, head-to-head and performing a push-and-retreat ritual until a rhythm is established. As the female tries to spin away, the male immediately counters, hoping to woo the female into accepting him as a mate.

Deuterosminthurus bicinctus courship dance © Bill Johnson
Deuterosminthurus bicinctus courship dance © Bill Johnson
Practicing Courtship Display Photo by Andy Murray
Practicing Courtship Display Photo by Andy Murray

It’s not really a mating ritual given springtails do not ‘mate’. The male (the small specimen) deposits a sperm drop on a stalk (spermatophore). The female (the large specimen; in this case a yellow color variant) will take up the sperm drop.   It might be better to call it a head-banging ritual.

I would encourage you to go to http://www.chaosofdelight.org to see Andy Murray’s wonderful gallery of springtail photographs.

Wise Eyes

Photo Credit: RobsWildlife.com 500px
Photo Credit: RobsWildlife.com 500px

Of all an owl’s features, perhaps the most striking is its eyes. The forward facing aspect of the eyes that give an owl its “wise” appearance, also give it a wide range of “binocular” vision (seeing an object with both eyes at the same time). This means the owl can see objects in 3 dimensions (height, width, and depth), and can judge distances in a similar way to humans.

Great Grey Owl by Jacques Larue/500px
Great Grey Owl by Jacques Larue/500px

An owl’s eyes are large in order to improve their efficiency, especially under low light conditions. In fact, the eyes are so well developed, that they are not eye balls as such, but elongated tubes.  An owl cannot “roll” or move its eyes – that is, it can only look straight ahead.  The owl makes up for this by being able to turn its head up to 270 degrees left or right and almost upside down.

Florida burrowing owlet Credit: Hisham Atallah/Minden Pictures
Florida burrowing owlet Credit: Hisham Atallah/Minden Pictures

The retina of an owl’s eye has an abundance of light-sensitive, rod-shaped cells appropriately called “rod” cells. Although these cells are very sensitive to light and movement, they do not react well to color.   Owls have extraordinary night vision, but see in limited color.

Red owl from Netherland Credit: Gert Jan Ijzerman/Minden Pictures
Red owl from Netherland Credit: Gert Jan Ijzerman/Minden Pictures

 

Orange eyed eagle owl. Credit: Wild Wonders of Europe/widstrand/Nature Picture Library
Orange eyed eagle owl. Credit: Wild Wonders of Europe/widstrand/Nature Picture Library
Snow owl by Markus van Hauten/500px
Snow owl by Markus van Hauten/500px

To protect their eyes, owls are equipped with 3 eyelids. They have a normal upper and lower eyelid, the upper closing when the owl blinks, and the lower closing up when the owl is asleep. The third eyelid is called a nictitating membrane, and is a thin layer of tissue that closes diagonally across the eye, from the inside to the outside. This cleans and protects the surface of the eye.

Third membrane on eyes of a young great horned own. Photo by Mack Hitch
Third membrane on eyes of a young great horned own. Photo by Mack Hitch
Sleepy owl
Sleepy owl

For protection from predators some insects have well developed eye spots.  Owl Butterflies are large, tropical butterflies found in secondary forests and rain forests from Mexico down to the Amazon in South America.  It is easy to see why they are called Owl Butterflies.  Their wings look like the face of an owl, and if you spread the wings out, you can actually see a pair of eyes looking straight at you.  Of course they cannot blink.

Owl butterfly
Owl butterfly