Genetic engineering will help prosthetics of joints

New Artificial Cartilage Fights Arthritis on Its Own

Julia Korowski, XXII CENTURY, based on the materials of Washington University in St. Louis: Stem cells engineered to grow cartilage, fight inflammation

Scientists from Washington University in St. Louis have grown articular cartilage from stem cells and with the help of genetic engineering forced it to produce anti-inflammatory substances. A description of the development was published in the journal Proceedings of the National Academy of Sciences (Moutos et al., Anatomically shaped tissue-engineered cartage with tunable and inducible anticytokine delivery for biological joint resurfacing).

Researchers believe that the new technique may someday change the approach to hip replacement surgery. Doctors are reluctant to make them for patients younger than fifty, because artificial joints, as a rule, last less than twenty years. Repeated surgery, during which doctors remove a worn-out endoprosthesis, increases the risk of infection and can lead to bone destruction. "Replacing a worn–out implant is a complex operation," says Farshid Guilak, one of the authors of the study. "We hope to prevent or at least delay the standard hip replacement surgery with a metal or plastic prosthesis."

Scientists have grown articular cartilage from stem cells obtained from the subcutaneous fat of several donors on a scaffold in the shape of the femoral head.

An illustration from an article in PNAS.

The scaffold is made of polycaprolactone, a biodegradable material that stimulates the growth of connective fibrous tissue. Researchers believe that cartilage from living tissue can be used for superficial endoprosthetics – an operation in which only the surface of the head of the hip joint is replaced with a prosthesis. This procedure is most often recommended for young patients, because it allows you to save a significant part of the bone tissue and postpone the operation for total endoprosthetics.

Superficial (left) and total (right) hip replacement.

Scientists have embedded a gene in the cartilage that triggers the production of an anti-inflammatory component. "When inflammation begins, we can give the patient a drug that activates the gene we have built in and reduces inflammation. This process can be stopped at any time by turning off the gene by stopping taking the drug," explains Gulyak.

Inflammation leads to the destruction of cartilage and exacerbation of pain, and scientists believe that gene therapy will cause arthritis to recede and prolong the life of the joint.

Currently, the scientific group is testing implants on laboratory animals. Gulyak assures that if everything goes well, clinical trials on humans will begin in three to five years.

Scaffold technology is the cultivation of cells on three–dimensional carrier substrates of natural or artificial origin (see, for example, chitosan) for the purpose of spatial formation of a future cellular organ or its fragment for a transplant.

Portal "Eternal youth" http://vechnayamolodost.ru  20.07.2016