Bengaluru, Jul 7 (PTI) Researchers at the Indian
Institute of Science (IISc) here have developed a
microparticle formulation that they said allows sustained
release of drugs to treat osteoarthritis, a chronic
They have designed a polymer matrix made of poly
(lactic-co-glycolic acid) or PLGA, an FDA-approved
biomaterial, to encapsulate rapamycin, an immunosuppressant
drug, an IISc release said.
Preliminary studies on cells cultured in the laboratory as
well as in mice models have shown promising results indicating
reduced inflammation and cartilage repair due to sustained
drug release, it said.
"In cell studies, rapamycin-loaded PLGA microparticles
could release the drug for up to 21 days, and in animal
studies, PLGA microparticles showed residence time up to 30
days after injecting the microparticles in the mice knee
joint," said Kaamini M Dhanabalan.
Kaamini is a PhD student at the Centre for BioSystems
Science and Engineering (BSSE), IISc, and first author of the
study published in the journal Biomaterials Science.
Osteoarthritis is associated with the wear and tear of
the cartilage, the smooth tissue that protects bone joints,
caused due to stress or aging.
The current treatment plan revolves more around managing
pain and inflammation than treating the disease.
Although several classes of drugs seemed promising in
preclinical trials, low drug retention and rapid clearance
from the target site have made clinical translation difficult,
according to the release.
"The formulation developed by the IISc team, however, has
a residence time of up to 30 days at the target site, with no
evident signs that it may cause discomfort to patients. Such a
sustained release system can improve patient compliance and
reduce hospital visits," the researchers said.
PLGA is widely used for drug delivery applications and
several drug formulations are currently used in clinics.
Rapamycin is commonly used to suppress immune response in
patients undergoing surgery for organ transplant to prevent
Preclinical studies have shown its potential for treating
osteoarthritis by preventing cell loss and cartilage damage,
thereby reducing inflammation.
However, the short drug retention time of 1-4 hours
demands frequent injections to maintain the therapeutic window
in the joints.
Therefore, Dhanabalan and her colleagues combined the
advantages of PLGA and rapamycin to create a system that would
allow sustained release of the drug. This was achieved by
encapsulating rapamycin in PLGA microparticles.
To evaluate the effectiveness of this formulation,
chondrocytes or cartilage cells were cultured and subjected to
various stresses to recreate osteoarthritis-like conditions
under laboratory settings.
This resulted in ailing chondrocytes with the hallmarks
of osteoarthritis. These damaged chondrocytes recovered from
osteoarthritis when treated with rapamycin-loaded PLGA
"Preliminary studies using this newly-designed
formulation can potentially reduce the frequent medical
intervention to once a month.
Detailed studies are in progress to explore the
functional potential in mouse models of osteoarthritis," said
Rachit Agarwal, Assistant Professor at BSSE, IISc, and senior
author of the study. PTI RS
Disclaimer :- This story has not been edited by Outlook staff and is auto-generated from news agency feeds. Source: PTI
More from Outlook Magazine