December 2, 2022

PolyU develops a revolutionary and highly effective targeted analgesic against osteoarthritis


HONG KONG, September 14, 2021 / PRNewswire / – Researchers at Hong Kong Polytechnic University (PolyU) have developed a revolutionary imaging-guided nanoparticle photothermal treatment for osteoarthritis pain, using the concept of targeted cancer therapy but applied instead to the protein that triggers pain signaling along the nervous system.

The new targeted theranostics for osteoarthritis pain, which offer both diagnostics and treatments, consist of gold nanorods coated with a two-dimensional nanomaterial, molybdenum disulfide. The coated nanorods are further fused with antibodies directed against nerve growth factor (NGF), the pain-triggering protein.

Nanoshafts fused with antibodies allow active and passive targeting on the generation of peripheral osteoarthritis pain. In addition, by directly binding NGF molecules to photothermal nanoparticles, which can transfer light energy to local heat, the NGF protein will be destroyed by heating with a near infrared laser.

Professor YANG Mo, Associate Head (Research) of the Department of Biomedical Engineering and a principal investigator of the study, said tests in mice suggest that targeted photothermal therapy provides satisfactory pain relief and improved motor function.

“This is the first time that the concept of targeted photothermal therapy for osteoarthritis pain via nanotechnology has been introduced,” said Professor Yang.

“Nanoparticles hold great promise for clinical translation to achieve lasting pain relief for days, compared to currently available drugs that can only relieve pain for hours,” he said. In their experience with mouse models of osteoarthritis, the laser-stimulated nanowires reduced signs of pain for three to four days.

Another principal investigator, Dr WEN Chunyi, Associate Professor, Department of Biomedical Engineering, said dual-track pain treatments with the antibody-fused nanosigines and laser stimulation more effectively reduced the amount of NGF in joint tissue and did not damage surrounding soft tissue or bone.

“A major concern of previous anti-NGF therapy in clinical trials is the development of destructive arthropathy after the use of high doses of anti-NGF antibodies. To address this problem, we have developed the targeted theranostic approach to locate and eliminate NGF so that a minimal dosage of anti-NGF antibodies is needed, ”explained Dr Wen, adding that only about 1/100 of the therapeutic dose used in previous clinical trials for the control of osteoarthritis pain is needed as part of the new approach.

Osteoarthritis is currently diagnosed by physical examination and, if necessary, by x-ray, MRI and arthroscopy. PolyU’s new technique enables a new approach to precise diagnosis – imaging of osteoarthritis pain, as nanowires localized to injured joints can be followed using photoacoustic imaging – a new non-invasive imaging modality that combines high contrast and good specificity of optical imaging, while providing the high resolution and depth of penetration offered by ultrasound imaging.

The research team chose gold nanorods because of their good photothermal properties and a molybdenum disulfide coating because of its good biocompatibility. In addition, molybdenum disulfide has good thermal conductivity and water solubility, as well as high absorbance in the near infrared, making it a superior contrast agent for photoacoustic imaging which improves the photothermal properties of nanowires.

The Lancet The Commission on Osteoarthritis has estimated that the disease has affected more than 500 million people worldwide. The World Health Organization also expects the prevalence of osteoarthritis to increase due to the aging of the population and the increase in related factors such as obesity.

Treatment for osteoarthritis focuses on reducing pain and improving joint movement. However, pain relievers are currently not targeted and some even have significant side effects. Meanwhile, total knee replacement surgery is expensive and requires a considerable wait time for surgery in public hospitals.

“Our molecular theranostic therapy, if it becomes clinically available, could postpone the need for costly joint replacement operations for years and significantly improve the quality of life of patients with osteoarthritis,” added the Dr Wen.

The research results have been published in the prestigious journal ACS Nano by the American Chemical Society and have been reported by Nature Rheumatology Reviews.

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SOURCE Hong Kong Polytechnic University