Nanoparticle delivery systems have good application prospects in the treatment of various diseases, especially in cancer treatment. The effect of drug delivery is regulated by the properties of nanoparticles. There have been many studies focusing on optimizing the structure of nanoparticles in recent years, and a series of achievements have been made. This review summarizes the optimization strategies of nanoparticles from three aspects—improving biocompatibility, increasing the targeting efficiency of nanoparticles, and improving the drug loading rate of nanoparticles—aiming to provide some theoretical reference for the subsequent drug delivery of nanoparticles.

Interaction between micro-objects is used to achieve the trapping, transport, and release of particles in the OET, enhancing the high-throughput transportation, and also to assemble some special microparticles structures.

The miniature soft robots have many promising applications, including micro-manipulations, endoscopy, and microsurgery, etc. Nevertheless, it remains challenging to fabricate a miniatured robot device that is thin, flexible, and can perform multimodal locomotor mobility with sensory capacity. In this study, we propose a miniatured, multi-layer (two shape memory polymer layers, a flexible copper heater, a silk particle enhanced actuator layer, and a sensory layer) four-limb soft robot (0.45-gram, 35mm-long, 12 mm-wide) with a total thickness of 1 mm. A precise flip-assembling technique is utilized to integrate multiple functional layers (fabricated by soft lithography, laser micromachining technologies). The actuator layer's elastic modulus increased ~100% by mixing with 20% silk particles by weight, which enhanced the mechanical properties of the miniature soft robot. We demonstrate that the soft robot can perform underwater crawling and jumping gliding locomotion. The sensing data depicts the robot's multiple bending configurations after the sensory data been processed by the microprocessor mounted on the robot torso. The miniatured soft robot can also be reshaped to a soft miniatured gripper. The proposed miniatured soft robots can be helpful for studying soft organisms' body locomotion as well as medical applications in the future.

Non-contact manipulation technology has a wide range of applications in the manipulation and fabrication of micro/nanomaterials. However, the manipulation devices are often complex, operated only by professionals, and limited by a single manipulation function. Here, we propose a simple versatile optoelectronic tweezer (OET) system that can be easily controlled for manipulating microparticles with different sizes. In this work, we designed and established an optoelectronic tweezer manipulation system. The OET system could be used to manipulate particles with a wide range of sizes from 2 μm to 150 μm. The system could also manipulate micro-objects of different dimensions like 1D spherical polystyrene microspheres, 2D rod-shaped euglena gracilis, and 3D spiral microspirulina. Optical microscopic patterns for trapping, storing, parallel transporting, and patterning microparticles were designed for versatile manipulation. The sorting, rotation, and assembly of single particles in a given region were experimentally demonstrated. In addition, temperatures measured under different objective lenses indicate that the system does not generate excessive heat to damage bioparticles. The non-contact versatile manipulation reduces operating process and contamination. In future work, the simple optoelectronic tweezers system can be used to control non-contaminated cell interaction and micro-nano manipulation.

Guidewires for endovascular interventional surgery are inevitably affected by high frictional resistance because of direct contact with the vascular wall, which greatly reduces the operation efficiency and safety. This article presents a method of applying radial ultrasonic microvibration at the proximal end of a conventional passive guidewire to reduce the frictional resistance. The proposed method theoretically reduced the frictional resistance by reducing the friction coefficient, actual contact area, and the net friction time between the guidewire and vascular wall. The effectiveness of the proposed method was experimentally demonstrated in designed simulations of the blood vessel environment, where the influences of the vibration amplitude on the drag reduction effect were considered. The results indicated that vibrating the guidewire at the resonant frequency with the designed device clearly reduced the drag with a maximum frictional reduction rate of 85.19%. At the resonant frequency, the change in frictional resistance showed a linear negative correlation with the applied vibration amplitude. The proposed method offers a new approach to improving the efficiency and safety of vascular interventional surgery.

Loading individual oocytes is a critical step for injecting RNA, expressing heterologous proteins, performing electrophysiological measurements, and so on. However, existing methods remain a challenge for automatically loading multiple single oocytes into different locations. Herein, a novel microfluidic chip on a robotic manipulator (chip‐on‐robot) with feedback control for flexible manipulation of multiple oocytes within a large spatial range is proposed. The manipulator automatically controls the microfluidic chip to reach different locations based on imaging feedback. The microfluidic chip then utilizes the hydrodynamic focusing effect of the main channel to separate oocytes for individual loading or reloading under capacitive sensor feedback. The separation distance reaches approximately 16 times the oocyte diameter. Moreover, capacitive signal feedback on the number of oocytes for flow direction control ensures the separation of all oocytes. For close‐loop control of the loading/reloading process, image‐based oocyte detection is combined using deep learning to calculate the target position of the oocyte. Finally, an automatic sequence is achieved to load multiple single oocytes into a well chip by using the chip‐on‐robot. As a demonstration, the oocytes are reloaded into a specified location based on the conditions. The proposed chip‐on‐robot with feedback control has significant advantages in the micromanipulation of oocytes.