Fig. 1From: Intra-articular delivery of celastrol by hollow mesoporous silica nanoparticles for pH-sensitive anti-inflammatory therapy against knee osteoarthritisTransmission electron microscopy (TEM) images of solid SiO2 (a), HMSNs (b) and CSL@HMSNs-Cs (c). Scale bars, 50 nmBack to article page