Non-contact electrical stimulation as an effective means to promote wound healing.

Electrical stimulation has been demonstrated to have beneficial effects in skin tissue repair. However, most electrical stimulations are applied with percutaneous electrode, which is prone to causing serious trauma. Using non-contact electrical stimulation (NCES) is expected to reduce the potential risk. In this study, NCES was expediently exerted by a self-designed practical device. Electrode plates of 10-cm spacing with appropriate side lengths of 21 and 30 cm were selected by EF distribution analysis for applying NCES to cells and mice, respectively, and the real EF strengths were measured. The change of loading voltage which had no effect on the regular pattern of EF distribution could be used as a single factor to explore the effect of NCES on wound healing. It was subsequently demonstrated that 53 mV mm-1 NCES facilitated the migration and proliferation of HaCaT cells and HDFs in vitro, and the M2-type polarization of macrophages. Moreover, 54 and 84 mV mm-1 NCESs accelerated the wound healing rate of model mice from the perspective of reducing scarring, enhancing collagen synthesis and increasing angiogenesis in vivo. The promoting role of NCES in wound healing showed the potential to initiate new possibilities for the clinical treatment of skin tissue injuries.

Preparation of Magnetic-Luminescent Bifunctional Rapeseed Pod-Like Drug Delivery System for Sequential Release of Dual Drugs.

Drug delivery systems (DDSs) limited to a single function or single-drug loading are struggling to meet the requirements of clinical medical applications. It is of great significance to fabricate DDSs with multiple functions such as magnetic targeting or fluorescent labeling, as well as with multiple-drug loading for enhancing drug efficacy and accelerating actions. In this study, inspired by the dual-chamber structure of rapeseed pods, biomimetic magnetic-luminescent bifunctional drug delivery carriers (DDCs) of 1.9 ± 0.3 µm diameter and 19.6 ± 4.4 µm length for dual drug release were fabricated via double-needle electrospraying. Morphological images showed that the rapeseed pod-like DDCs had a rod-like morphology and Janus dual-chamber structure. Magnetic nanoparticles and luminescent materials were elaborately designed to be dispersed in two different chambers to endow the DDCs with excellent magnetic and luminescent properties. Synchronously, the Janus structure of DDCs promoted the luminescent intensity by at least threefold compared to single-chamber DDCs. The results of the hemolysis experiment and cytotoxicity assay suggested the great blood and cell compatibilities of DDCs. Further inspired by the core-shell structure of rapeseeds containing oil wrapped in rapeseed pods, DDCs were fabricated to carry benzimidazole molecules and doxorubicin@chitosan nanoparticles in different chambers, realizing the sequential release of benzimidazole within 12 h and of doxorubicin from day 3 to day 18. These rapeseed pod-like DDSs with excellent magnetic and luminescent properties and sequential release of dual drugs have potential for biomedical applications such as targeted drug delivery, bioimaging, and sustained treatment of diseases.