Emerging Advancements in Piezoelectric Nanomaterials for Dynamic Tumor Therapy.

Cancer is one of the deadliest diseases, having spurred researchers to explore effective therapeutic strategies for several centuries. Although efficacious, conventional chemotherapy usually introduces various side effects, such as cytotoxicity or multi-drug resistance. In recent decades, nanomaterials, possessing unique physical and chemical properties, have been used for the treatment of a wide range of cancers. Dynamic therapies, which can kill target cells using reactive oxygen species (ROS), are promising for tumor treatment, as they overcome the drawbacks of chemotherapy methods. Piezoelectric nanomaterials, featuring a unique property to convert ultrasound vibration energy into electrical energy, have also attracted increasing attention in biomedical research, as the piezoelectric effect can drive chemical reactions to generate ROS, leading to the newly emerging technique of ultrasound-driven tumor therapy. Piezoelectric materials are expected to bring a better solution for efficient and safe cancer treatment, as well as patient pain relief. In this review article, we highlight the most recent achievements of piezoelectric biomaterials for tumor therapy, including the mechanism of piezoelectric catalysis, conventional piezoelectric materials, modified piezoelectric materials and multifunctional piezoelectric materials for tumor treatment.

Soft mesoporous organosilica nanorods with gold plasmonic core for significantly enhanced cellular uptake.

Soft nanoparticles have attracted increasing attention in biomedical fields because of their unique biological behaviors such as long circulation and high cellular uptake. However, previously reported soft nanoparticles are generally spherical or torispherical in shape, and non-spherical soft nanoparticles are rarely reported because of the shape is thermodynamically unstable for typical soft materials (e.g., liposomes and micelles). Herein, soft mesoporous organosilica nanorods with gold plasmonic core protected with poly-ethylene imine (GNR@SMON/PEI) have been successfully synthesized, for the first time, by a dispersive-protection etching method, in which rod-like solid mesoporous organosilicas with gold nanorod are firstly shielded with PEI (GNR@MON/PEI) and then etched with aqueous NaOH solution. The prepared GNR@SMON/PEI inherits the rod morphology of the mother particle, showing wrinkled morphology and excellent dispersity thanks to the dispersive-protection effect of PEI. In addition, the GNR@SMON/PEI possesses a uniform size (174 × 105 nm), well-defined mesopores (3.9 nm), high surface area (355 m2/g) and large pore volume (0.35 m3/g). Notably, the soft GNR@SMON/PEI exhibits significantly lower Young's modulus (120.2 MPa) in contrast with the hard counterpart (361.4 MPa). Furthermore, after being decorated with hyaluronic acid (HA), the soft GNR@SMON/PEI-HA exhibits excellent in vitro and in vivo biocompatibility. The soft GNR@SMON/PEI-HA has achieved 3-fold cellular uptake efficiency in contrast with the hard one, indicating great potential for biomedical applications. Taken together, this work reports the controllable synthesis of a soft mesoporous nanorod with high cellular uptake efficiency, providing a vital strategy for the synthesis of non-spherical soft nanoparticles and a new nanoplatform for various biomedical applications in future.