Local injection of a freshly manufactured 35 kDa hyaluronan fragment reduces neuropathic and inflammatory pain: A clinical study

To investigate the ability of the 35 kDa low-molecular-weight hyaluronan fragment (HA35) to relieve neuropathic and inflammatory pain, including postherpetic neuralgia and shoulder, neck, back and temporomandibular pain. Ten patients with postherpetic neuralgia and 26 patients with shoulder, neck, back or temporomandibular pain were studied and assessed. The 35 kDa hyaluronan fragment (HA35) was prepared by mixing hyaluronidase and 100 mg of high-molecular-weight HA at room temperature for 20 mins. This mixture was locally injected once at the pain point or where the nerve trunk innervated the pain point. Patients scored their pain and comfort on the numerical pain rating scale (NPRS) and the General Comfort Questionnaire (GCQ). After treatment, the NPRS scores and GCQ scores improved. Patients with postherpetic neuralgia and shoulder, neck, back or temporomandibular pain had significantly lower NPRS scores at 30 min to 180 min after injection, especially at 180 min ( p < .001). The GCQ scores after treatment for 24 h was significantly greater than that before treatment ( p < .01). No adverse reactions occurred. The 35 kDa hyaluronan fragment (HA35) effectively relieved postherpetic neuralgia-induced neuropathic pain and shoulder, neck, back and temporomandibular inflammatory pain.Clinical Trial Registration: NCT05809700 at https://www.clinicaltrials.gov .