No abstract

Cathepsin B is a papain-family cysteine protease that is normally located in lysosomes, where it is involved in the turnover of proteins and plays various roles in maintaining the normal metabolism of cells. This protease has been implicated in pathological conditions, e.g., tumor progression and arthritis. In disease conditions, increases in the expression of cathepsin B occur at both the gene and protein levels. At the gene level, the altered expression results from gene amplification, elevated transcription, use of alternative promoters and alternative splicing. These molecular changes lead to increased cathepsin B protein levels and in turn redistribution, secretion and increased activity. Here we focus on the molecular regulation of cathepsin B and attendant implications for tumor progression and arthritis. The potential of cathepsin B as a therapeutic target is also discussed.

Nearly monodispersed FeNi3 submicrometre spheres with an average diameter of 220 nm were synthesized by a simple low temperature reduction method. SiO2@FeNi3 core–shell structured submicrometre spheres with 25 nm thick SiO2 shell were then fabricated by a sol–gel process. A significant enhancement of electromagnetic absorption (EMA) performance was achieved by the silica coating over the 2–18 GHz. The reflection loss (RL) exceeding −20 dB of the composite was obtained over 6.7–15.1 GHz by choosing an appropriate sample thickness between 2.1 and 3.3 mm, and an optimal RL of −61.3 dB was obtained at 8.7 GHz with a thin absorber thickness of 2.9 mm. The coating of the dielectric silica shell significantly enhanced the EMA performance due to the enhancement of interface polarization at the alloys and dielectric interfaces.

Biomimetic cell membrane coated nanoparticles (NPs) with desirable features have been extensively applied for various personalized biomedicine. However, there have not been relative explorations by employing the membrane nanocomplexes for small interfering RNA (siRNA) delivery. Herein, Fe 3 O 4 @PDA NPs with good photothermal capability were applied for efficient siRNA loading and delivery, which were then coated by mesenchymal stem cells (MSCs) to form a membrane. The data showed that MSCs membrane coated Fe 3 O 4 @PDA−siRNA NPs (Fe 3 O 4 @PDA−siRNA@MSCs) maintained the photothermal functionality and the capability of magnetic resonance imaging inherited from Fe 3 O 4 @PDA. The synthesized nanocomplexes exhibited excellent abilities in the delivery of siRNA into DU145 cells. Furthermore, Fe 3 O 4 @PDA−siRNA@MSCs NPs delivering siRNA against Plk1 gene could inhibit the expression of endogenous Plk1 gene and cause obvious apoptosis in DU145 cells. The synergistic combination of photothermal treatment and gene silencing showed obvious antitumor efficacy in a DU145 xenograft mice model. On the basis of preliminary in vitro and in vivo studies, Fe 3 O 4 @PDA−siRNA@MSCs NPs hold considerable promise as a carrier for gene and photothermal therapy.