Triboelectric-Responsive Drug Delivery Hydrogel for Accelerating Infected Wound Healing.

Electrotherapy is of great interest in the field of tissue repair as an effective, well-tolerated, and noninvasive treatment. Triboelectric nanogenerator (TENG) has shown advantages in promoting wound healing due to its peak output characteristic and low Joule heating effect. However, it is limited in infected wound healing due to poor antimicrobial capacity. Here, a wearable triboelectric stimulator (WTS) is developed that consists of a flexible TENG (F-TENG) and a triboelectric-responsive drug delivery hydrogel (TR-DDH) for healing of bacterium-infected wounds. F-TENG can generate pulsed current to wounds by converting mechanical energy from body movements. Polypyrrole is prone to reduction and volume contraction under electrical stimulation, resulting in desorption of curcumin nanoparticles (CUR NPs) from the polypyrrole in TR-DDH. Therefore, the highly efficient and controllable release of CUR NPs can be achieved by triboelectric stimulation. According to the in vitro and in vivo experiments, WTS has the greatest antimicrobial effect and the fastest promotion of infected wound healing compared to treatment with electrical stimulation or curcumin. Finally, the safety assessment demonstrates that the WTS has excellent tissue safety for chronic wound healing. Synergistic therapy with WTS provides an efficient strategy for chronic wound healing and smart-responsive drug delivery systems.

Controllable silicon nanostructures featuring stable fluorescence and intrinsic in vitro and in vivo anti-cancer activity.

In this manuscript, we demonstrate that the in situ growth of fluorescent silicon (Si) nanomaterials is stimulated when organosilicane molecules interact with different green teas, producing multifunctional Si nanomaterials with controllable zero- (e.g., nanoparticles), two- (e.g., nanosheets), and three- (e.g., nanospheres) dimensional nanostructures. Such green tea-originated Si nanomaterials (GTSN) exhibit strong fluorescence (quantum yield: ∼19-30%) coupled with ultrahigh photostability, as well as intrinsic anti-cancer activity with high specificity (e.g., the GTSN can accurately kill various cancer cells, rather than normal cells). Taking advantage of these unique merits, we further performed systematic in vitro and in vivo experiments to interrogate the mechanism of the green tea- and GTSN-related cancer prevention. Typically, we found that the GTSN entered the cell nuclei and induced cell apoptosis/death of cancer cells. The prepared GTSN were observed in vivo to accumulate in the tumour tissues after 14-d post-injection, leading to an efficient inhibition of tumour growth. Our results open new avenues for designing novel multifunctional and side-effect-free Si nanomaterials with controllable structures.

Multifunctional Silicon-Carbon Nanohybrids Simultaneously Featuring Bright Fluorescence, High Antibacterial and Wound Healing Activity.

In this work, a class of multifunctional silicon-carbon nanohybrids (designated as SiCNs), which simultaneously possess aqueous dispersibility, bright fluorescence (photoluminescence quantum yield [PLQY]: ≈28%), as well as high antibacterial and wound healing activity, is presented. Taking advantage of these unique merits, cell distribution and pharmacological behavior of the SiCNs is first investigated through tracking their strong and stable fluorescence. The high bacteria inhibition ability (≈82.9% killing rate toward S. aureus) and hemostatic effects (shorten the bleeding time from ≈60 to ≈15 s) of the resultant SiCNs are then demonstrated. Moreover, the wound closure promotion activity (10% lead in wound contraction) is systematically demonstrated in vivo, which is especially suitable for wound healing applications. The results suggest the SiCNs as a new kind of high-performance multifunctional nanoagents suitable for various biological and biomedical utilizations.

Silicon nanostructures for cancer diagnosis and therapy.

The emergence of nanotechnology suggests new and exciting opportunities for early diagnosis and therapy of cancer. During the recent years, silicon-based nanomaterials featuring unique properties have received great attention, showing high promise for myriad biological and biomedical applications. In this review, we will particularly summarize latest representative achievements on the development of silicon nanostructures as a powerful platform for cancer early diagnosis and therapy. First, we introduce the silicon nanomaterial-based biosensors for detecting cancer markers (e.g., proteins, tumor-suppressor genes and telomerase activity, among others) with high sensitivity and selectivity under molecular level. Then, we summarize in vitro and in vivo applications of silicon nanostructures as efficient nanoagents for cancer therapy. Finally, we discuss the future perspective of silicon nanostructures for cancer diagnosis and therapy.

Silicon nanowire-based therapeutic agents for in vivo tumor near-infrared photothermal ablation.

The first example of silicon nanowire (SiNW)-based in vivo tumor phototherapy is presented. Gold nanoparticle (AuNP)-decorated SiNWs are employed as high-performance NIR hyperthermia agents for highly efficacious in vivo tumour ablation. Significantly, the overall survival time of SiNW-treated mice is drastically prolonged, with 100% of mice being alive and tumor-free for over 8 months, which is the longest survival time ever reported for tumor-bearing mice treated with nanomaterial-based NIR hyperthermia agents.