Nanoparticle injections hold hope for osteoarthritis patients

US researchers have designed a peptide-based nanoparticle, which when injected into an injured joint will not only suppress the inflammation immediately but also reduce the destruction of cartilage, thus lowering the risk for osteoarthritis.

Osteoarthritis is a type of arthritis that occurs when flexible tissue at the ends of bones wears down.

In this study, the nanoparticles were injected locally shortly after injury into the joint of the participants to penetrate into the injured cartilage to prevent cartilage breakdown that could eventually cause osteoarthritis.

Within 24 hours the nanoparticles were at work to tame the inflammation in the joint, the researchers said.

"These nanoparticles remain in the joint longer (than the traditional anti-inflammotory drugs) and help prevent cartilage degeneration," said Associate Professor Christine Pham from Washington University in St. Louis in the US.

"The nanoparticles are injected directly into the joint, and due to their size, they easily penetrate into the cartilage to enter the injured cells," added Professor Samuel Wickline of Washington University.

The newly developed nanoparticles carry a peptide derived from a natural protein called melittin that has been modified to enable it to bind to a molecule called small interfering RNA (siRNA).

The melittin delivers siRNA to the damaged joint, interfering with inflammation in cells.

It is more than 10 times smaller than a red blood cell, which helps them penetrate deeply into tissues, the researchers noted.

The findings were reported online in the early edition of the Proceedings of the National Academy of Sciences.

--IANS

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