Category Archives: Medicine

Artificial retina could someday help restore vision

141112102521-large

The loss of eyesight, often caused by retinal degeneration, is a life-altering health issue for many people, especially as they age. But a new development toward a prosthetic retina could help counter conditions that result from problems with this crucial part of the eye.

Yael Hanein and colleagues point out that a growing range of medical devices has become available to treat conditions, including visual impairment, that involve sending sensory signals to the brain. Patients with one type of eye disorder called age-related macular degeneration (AMD), for example, could potentially benefit from such a device, they say. AMD usually affects people age 60 or older who have damage to a specific part of the retina, limiting their vision. Scientists are trying different approaches to develop an implant that can “see” light and send visual signals to a person’s brain, countering the effects of AMD and related vision disorders. But many attempts so far use metallic parts, cumbersome wiring or have low resolution. The researchers, an interdisciplinary team from Tel Aviv University, the Hebrew University of Jerusalem Centers for Nanoscience and Nanotechnology and Newcastle University, wanted to make a more compact device.
The researchers combined semiconductor nanorods and carbon nanotubes to create a wireless, light-sensitive, flexible film that could potentially act in the place of a damaged retina. When they tested it with a chick retina that normally doesn’t respond to light, they found that the film absorbed light and, in response, sparked neuronal activity. In comparison with other technologies, the researchers conclude theirs is more durable, flexible and efficient, as well as better able to stimulate neurons.
The authors acknowledge funding from the Israel Ministry of Science and Technology, the European Research Council and the Biotechnology and Biological Sciences Research Council.

read more

Possible alternative to antibiotics: Nanoparticles made of lipids

A novel substance for the treatment of severe bacterial infections has been developed to work without antibiotics. Scientists say that this would prevent the development of antibiotic resistance. Scientists engineered artificial nanoparticles made of lipids, “liposomes” that closely resemble the membrane of host cells. These liposomes act as decoys for bacterial toxins and so are able to sequester and neutralize them.

Ever since the development of penicillin almost 90 years ago, antibiotics have remained the gold standard in the treatment of bacterial infections. However, the WHO has repeatedly warned of a growing emergence of bacteria that develop antibiotic resistance. Once antibiotics do no longer protect from bacterial infection, a mere pneumonia might be fatal.
Alternative therapeutic concepts which lead to the elimination of bacteria, but do not promote resistance are still lacking.
A team of international scientists has tested a novel substance, which has been developed by Eduard Babiychuk and Annette Draeger from the Institute of Anatomy, University of Bern in Switzerland. This compound constitutes a novel approach for the treatment of bacterial infections: the scientists engineered artificial nanoparticles made of lipids, “liposomes” that closely resemble the membrane of host cells. These liposomes act as decoys for bacterial toxins and so are able to sequester and neutralize them. Without toxins, the bacteria are rendered defenseless and can be eliminated by the cells of the host’s own immune system. The study will be published in Nature Biotechnology Nov 2nd.
Artificial bait for bacterial toxins
In clinical medicine, liposomes are used to deliver specific medication into the body of patients. Here, the Bernese scientists have created liposomes which attract bacterial toxins and so protect host cells from a dangerous toxin attack.
“We have made an irresistible bait for bacterial toxins. The toxins are fatally attracted to the liposomes, and once they are attached, they can be eliminated easily without danger for the host cells,” says Eduard Babiychuk who directed the study.
“Since the bacteria are not targeted directly, the liposomes do not promote the development of bacterial resistance,” adds Annette Draeger. Mice which were treated with the liposomes after experimental, fatal septicemia survived without additional antibiotic therapy.

read more

Transplant of stem-cell-derived dopamine neurons shows promise for Parkinson’s disease

Parkinson’s disease is an incurable movement disorder that affects millions of people around the world, but current treatment options can cause severe side effects and lose effectiveness over time. In a study published by Cell Press November 6th in Cell Stem Cell, researchers showed that transplantation of neurons derived from human embryonic stem cells (hESCs) can restore motor function in a rat model of Parkinson’s disease, paving the way for the use of cell replacement therapy in human clinical trials. “Our study represents an important milestone in the preclinical assessment of hESC-derived dopamine neurons and provides essential support for their usefulness in treating Parkinson’s disease,” says senior study author Malin Parmar of Lund University.

read more

New treatment for life-threatening bacterial diseases identified

A new treatment against antibiotic resistant bacterial infections has been identified by researchers. This could prevent unnecessary deaths from diseases such as pneumonia and sepsis. The treatment is a valuable alternative to current medications, particularly for infections that have become resistant to antibiotics.
Published in Nature Biotechnology, the study showed that specially engineered lipid (fat) bodies, called liposomes, can be used to prevent bacterial toxins from killing human cells.
This could prevent unnecessary deaths from diseases such as pneumonia and sepsis. The treatment is a valuable alternative to current medications, particularly for infections that have become resistant to antibiotics.
The bacterial toxins, produced by major human pathogens such as Streptococcus pneumonia, Streptococcus pyogenes and Methicillin Resistant Staphlycoccus aureus (MRSA) were neutralised as they bound to the liposomes instead of human cells.
Liposomes are already licensed for medical use as carriers for drug delivery and are nontoxic to humans. The research team has now shown that they can also be used therapeutically, either alone or in conjunction with antibiotics to combat bacterial infections and to minimize toxin-induced tissue damage and inflammation.
Global burden
Professor Aras Kadioglu, from the University’s Institute of Infection and Global Health, explains: “The global burden of bacterial disease is very high and set against a backdrop of increasing antimicrobial resistance. There is an urgent need for alternatives to antibiotics that are effective and less likely to lead to drug resistance.
“Bacterial toxins are the key mediators of morbidity and mortality for many pathogens and we have developed a novel treatment to specifically neutralize them.”
“Our data provides a strong case for pursuing liposome-based, toxin-sequestrating therapy for use as a clinical treatment for life-threatening bacterial infections.”
Dr Daniel Neill, also from the University, added: “This treatment can be used for antibiotic resistant bacteria as well as for the treatment of antibiotic-sensitive bacteria, to prevent the release of toxins that leads to deterioration of the clinical condition of the patient.”

read more

Investigations launched into artificial tracheas

1.16431_42-49144207

One of Europe’s most prestigious medical universities, the Karolinska Institute in Stockholm, has launched two investigations into the clinical procedures of a doctor famed for performing potentially revolutionary, bioengineered trachea transplants.

Since 2008, Paolo Macchiarini, a thoracic surgeon at the Karolinska Institute, has replaced parts of airways damaged by injury, cancer or other disorders in 17 patients. In the earlier cases, he transplanted parts of tracheas taken from cadavers; in his later work, he transplanted synthetic tracheas. In both procedures, before transplantation, he would treat the tracheas with stem cells taken from the patient’s bone marrow, which he says helps the transplants to act like biological tissue.

read more