Immune Cell Macrophage Responsible For Tissue Regeneration

Australian Regenerative Medicine Institute (ARMI) researchers have discovered that white blood cells called macrophages may hold the key to tissue regeneration. This discovery may help in new therapies involving repairing and regenerating tissues in the heart, spinal cord and lungs.

Researchers studying salamanders have noted that the reptile's ability to regenerate its tail without any sign of scars may be due to this immune cell. The researchers found that without the presence of macrophages, the salamanders do not regenerate a lost limb.

By studying this ability, the discovery can help in research towards therapies involving organs where damaged tissues can regenerate without scarring. Sensitive organs such as the heart and the spinal cord can benefit with this discovery. Researchers at ARMI are now looking to replicate this process with human tissues.

Creating Living Tissues Through Synthetic Biology and 3D Printers

A custom-built programmable 3D printer can create materials with several of the properties of living tissues, Oxford University scientists have demonstrated: Droplet network c.500 microns across with electrically conductive pathway between electrodes mimicking nerve.
Credit: Oxford University/G Villar

Researchers have used a 3D printer to create a synthetic living tissue that can perform some of the functions of the cells inside the human body.

Synthetic biology is the science of designing biological components for a specific purpose. Cells and molecules are used to create parts, devices, and biological systems through DNA nanotechnology, bionanodevices, and genetic engineering. These biological components are used to perform a specific function or part of a bigger biological system.

Current applications of synthetic biology in the medical field have addressed specific needs such as diagnosing diseases, monitoring and identifying cancer cells and also for treatment of common ailments such as acne. A common application for synthetic biology is the creation of enzymes. Enzymes are natural molecules that create necessary and beneficial chemical reactions in the cells and tissues of the body.

Processes used by synthetic biology involve bioengineering through DNA nanotechnology and genetic manipulation. A new way to create biological structures uses 3D printers that can "print" or create three dimensional objects made up of biological material that would behave in a specific way at a specified time or situation.

Engineering Patient Specific Articular Cartilage Tissues With Induced Pluripotent Stem Cells

Scientists used induced pluripotent stem cells (iPSCs) to produce and engineer cartilage that opens up new treatments and therapies for patients with damaged cartilage, cartilage injury, and osteoarthritis.

Since the introduction of stem cell technology, its manner of procurement has garnered much moral debate. Initially, stem cells are taken from human embryos about four or five days after fertilization.

Stem cells are pluripotent. This means that they have the ability to transform or differentiate into a higher form of cell, tissue or organ. It is this ability that scientists look to as the next evolution of medical science.

Cyborg Tissues - Bioengineered Tissues With Embedded Nanoelectronics Developed

The science of replacing or improving biological functions by using cells, technology, engineering materials and methods combined with biochemical and physio-chemical factors is called Tissue engineering.

It is modifying an existing organ or tissue in order to repair it or enhance its performance and function.

Tissue engineering encompasses a broad range of applications. But the technology is more identified with its use in repairing or replacing tissues such as bone, cartilage, blood vessels, etc. It is also being implemented in the development of artificially created ones to replace or support biochemical functions/organs such as an artificial pancreas or liver.

Now, researchers have merged the biological and the electronic and developed a method to grow 'cyborg' tissues with embedded nano-electronics to produce a new generation of bioengineered tissues.

Merging the biological and the electronic

Harvard scientists have, for the first, time created a type of "cyborg" tissue by embedding a three-dimensional network of functional, bio-compatible nanoscale wires into engineered human tissues.

As described in a paper published August 26 in Nature Materials, a multi-institutional research team led by Charles M. Lieber, the Mark Hyman, Jr. Professor of Chemistry at Harvard and Daniel Kohane, a Harvard Medical School professor in the Department of Anesthesia at Children's Hospital Boston developed a system for creating nanoscale "scaffolds" which could be seeded with cells which later grew into tissue.

Also contributing to the work were Robert Langer, from the Koch Institute at the Massachusetts Institute of Technology, and Zhigang Suo, the Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials at Harvard's School of Engineering and Applied Sciences.

"The current methods we have for monitoring or interacting with living systems are limited," said Lieber. "We can use electrodes to measure activity in cells or tissue, but that damages them. With this technology, for the first time, we can work at the same scale as the unit of biological system without interrupting it. Ultimately, this is about merging tissue with electronics in a way that it becomes difficult to determine where the tissue ends and the electronics begin."

The research addresses a concern that has long been associated with work on bioengineered tissue – how to create systems capable of sensing chemical or electrical changes in the tissue after it has been grown and implanted. The system might also represent a solution to researchers' struggles in developing methods to directly stimulate engineered tissues and measure cellular reactions.

"In the body, the autonomic nervous system keeps track of pH, chemistry, oxygen and other factors, and triggers responses as needed," Kohane explained. "We need to be able to mimic the kind of intrinsic feedback loops the body has evolved in order to maintain fine control at the cellular and tissue level."