Cinnamon cassia oil chitosan nanoparticles: Physicochemical properties and anti-breast cancer activity.

The aim of this study was to prepare Cinnamomum cassia essential oil (CEO) impregnated chitosan nanoparticles (CS-CEO) and assess its pharmacological activity against breast cancer. Cinnamon oil-loaded chitosan nanoparticles were investigated for their physicochemical properties, stability, and anti-cancer activities both in vitro and in vivo. The prepared CS-CEO nanoparticles have a particle size, zeta-potential, entrapment efficiency and drug loading of (215.40 ± 3.90) nm, (51.70 ± 1.90) mV, (83.37 ± 0.4)% and (26.42 ± 0.65)%, respectively. CS-CEO showed a regular, uniform, and spherical or quasi-spherical structure under a transmission electron microscope. CS-CEO remained stable upon storage at 4 °C. CS-CEO exhibited enhanced in vitro antitumor activity (52 µg/mL) compared to CEO. The mechanism might be related to the up-regulation of Caspase-3 and AIF protein expression. In in vivo experiments, CS-CEO suppressed the growth of 4T1 breast cancer cells transplanted into mice, inhibited tumor cell proliferation, and induced apoptosis by reducing the expression of the Ki-67 protein. These results indicated that CEO encapsulated in chitosan had a higher physical stability and was also more effective against 4T1 breast tumor model, which can be used as a reference for the application of volatile oil components in traditional Chinese medicine.

Maskless Micro/Nanopatterning and Bipolar Electrical Rectification of MoS2 Flakes Through Femtosecond Laser Direct Writing.

Molybdenum disulfide (MoS2) micro/nanostructures are desirable for tuning electronic properties, developing required functionality, and improving the existing performance of multilayer MoS2 devices. This work presents a useful method to flexibly microprocess multilayer MoS2 flakes through femtosecond laser pulse direct writing, which can directly fabricate regular MoS2 nanoribbon arrays with ribbon widths of 179, 152, 116, 98, and 77 nm, and arbitrarily pattern MoS2 flakes to form micro/nanostructures such as single nanoribbon, labyrinth array, and cross structure. This method is mask-free and simple and has high flexibility, strong controllability, and high precision. Moreover, numerous oxygen molecules are chemically and physically adsorbed on laser-processed MoS2, attributed to roughness defect sites and edges of micro/nanostructures that contain numerous unsaturated edge sites and highly active centers. In addition, electrical tests of the field-effect transistor fabricated from the prepared MoS2 nanoribbon arrays reveal new interesting features: output and transfer characteristics exhibit a strong rectification (not going through zero and bipolar conduction) of drain-source current, which is supposedly attributed to the parallel structures with many edge defects and p-type chemical doping of oxygen molecules on MoS2 nanoribbon arrays. This work demonstrates the ability of femtosecond laser pulses to directly induce micro/nanostructures, property changes, and new device properties of two-dimensional materials, which may enable new applications in electronic devices based on MoS2 such as logic circuits, complementary circuits, chemical sensors, and p-n diodes.