Gold nanoclusters for optimizing the general efficacies of herbal medicines on nerve repair after spinal cord injury

Spinal cord injury (SCI) leads to massive releases of inflammatory factors, which damage nerves and cause neurological disorders. Some herbal medicines show neuroprotective and anti-neuroinflammation effects, which may relieve nerve damages after SCI. Unfortunately, many herbal medicines are insufficient to recover the diseases because of the instability in the physiological environment and weak anti-inflammatory responses. Herein, gold nanoclusters (AuNCs) in conjugation with three herbal medicines including berberine (BRB), astragalus polysaccharides (APS), and diosgenin (DIO) were found to promote the general drug efficiencies, which more remarkably inhibited the inflammation factors such as NF-κB by more than 53.1%, 30.5%, and 30.2% and IKKβ by more than 45.0%, 41.8% and 31.9% respectively in vitro. AuNCs conjugated herbal medicines also reduced inflammatory responses in vivo and more effectively recovers nerve functions after SCI by observing the increased Basso, Beattie, and Bresnahan (BBB) exercise score from 12.2 to 13.2, 11.6 to 14.2, and 11.2 to 12.8 compared to BRB, APS, and DIO only. This work suggests AuNCs may generally promote the therapeutic effects of various herbal medicines.