Intra-articular delivery of celastrol by hollow mesoporous silica nanoparticles for pH-sensitive anti-inflammatory therapy against knee osteoarthritis oleh Tian Jin, Di Wu, Xiao-Ming Liu, Jiang-Tao Xu, Bing-Jie Ma, Yun Ji, Yu-Ying Jin, Si-Yin Wu, Tao Wu, Ke Ma