High-performance magnetic metal microrobot prepared by a two-photon polymerization and sintering method.

Magnetically-actuated microrobots (MARs) exhibit great potential in biomedicine owing to their precise navigation, wireless actuation and remote operation in confined space. However, most previously explored MARs unfold the drawback of hypodynamic magnetic torque due to low magnetic content, leading to their limited applications in controlled locomotion in fast-flowing fluid and massive cargo carrying to the target position. Here, we report a high-performance pure-nickel magnetically-actuated microrobot (Ni-MAR), prepared by a femtosecond laser polymerization followed by sintering method. Our Ni-MAR possesses a high magnetic content (∼90 wt%), thus resulting in enhanced magnetic torque under low-strength rotating magnetic fields, which enables the microrobot to exhibit high-speed swimming and superior cargo carrying. The maximum velocity of our Ni-MAR, 12.5 body lengths per second, outperforms the velocity of traditional helical MARs. The high-speed Ni-MAR is capable of maintaining controlled locomotion in fast-flowing fluid. Moreover, the Ni-MAR with massive cargo carrying capability can push a 200-times heavier microcube with translation and rotation motion. A single cell and multiple cells can be transported facilely by a single Ni-MAR to the target position. This work provides a scheme for fabricating high-performance magnetic microrobots, which holds great promise for targeted therapy and drug delivery in vivo.

Extraction of Radix trichosanthis Polysaccharides for Potential Antihyperlipidemic Application.

This study focused on the optimization of ultrasound-assisted compound enzyme extraction for polysaccharides (RTPs) from Radix trichosanthis by orthogonal experiment and response surface methodology, and then its extraction kinetics model and antihyperlipidemic activities were studied. The optimum extraction process was as follows: cellulase-1.0%, papain-1.0%, pectase-0.5%, pH-5, extraction temperature-50°C, and liquid-to-solid ratio-30 mL/g; prediction value of RTPs was 7.54%; the experimental yield of RTPs was 7.22%, while 50 minutes was optimized in Weibull kinetics model. Then high-dose groups of RTP extract could reduce the TC, TG, and LDL-C levels and increase the level of HDL-C in high-fat mice, with the ability to lower the MDA content and enhance SOD level.