The high printing efficiency and easy availability of desktop digital light processing (DLP) printers have made DLP 3D printing a promising technique with increasingly broad application prospects, particularly in personalized medicine. The objective of this study was to fabricate and evaluate medical samples with external and internal structures using the DLP technique. The influence of different additives and printing parameters on the printability and functionality of this technique was thoroughly evaluated. It was observed that the printability and mechanical properties of external structures were affected by the poly(ethylene glycol) diacrylate (PEGDA) concentration, plasticizers, layer height, and exposure time. The optimal printing solutions for 3D external and internal structures were 100% PEGDA and 75% PEGDA with 0.25 mg/mL tartrazine, respectively. And the optimal layer height for 3D external and internal structures were 0.02 mm and 0.05 mm, respectively. The optimal sample with external structures had an adequate drug-loading ability, acceptable sustained-release characteristics, and satisfactory biomechanical properties. In contrast, the printability of internal structures was affected by the photoabsorber, PEGDA concentration, layer height, and exposure time. The optimal samples with internal structures had good morphology, integrity and perfusion behavior. The present study showed that the DLP printing technique was capable of fabricating implants for drug delivery and physiological channels for in vivo evaluation.

Micro/nanomotors are able to convert energy in different forms into propulsion and movement with predesigned directions and velocities, enabling them to be self‐propelled carriers and vehicles for the delivery of active pharmaceutical ingredients and other biomedical cargos to the target sites such as tumors. However, the inadequate energy and noncontrollable moving directions remain the grand challenges for their promising applications. Recently, an increasing attention has been paid to these issues and numerous reported researches have focused to design and develop more efficient and precisely controllable micro/nanomotors with different methods. This review aims to summarize those studies and to introduce newly developed micro/nanomotors including synthetic micro/nanomotors and biohybrid motors, discussing the control mechanisms as well as advantages and limitations thereof. Conclusions and future perspectives are also provided in brief.

In this study, a micro-molding technology was used to prepare the microneedles (MNs), while a texture analyzer was used to measure its Young’s modulus, Poisson’s ratio and compression breaking force, to evaluate whether the MNs can penetrate the skin. The effects of different materials were characterized by their ability to withstand stresses using the Structural Mechanics Module of COMSOL Multiphysics. Carboxymethylcellulose (CMC) was chosen as the needle formulation material with varying quantities of polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) and hyaluronic acid (HA) to adjust the viscosity, brittleness, hardness and solubility of the material. The results of both the experimental tests and the predictions indicated that the hardest tip material had a solids content of 15% ($w/w$ ) with a 1:2 ($w/w$) CMC: HA ratio. Furthermore, it was shown that a solid content of 10% ($w/w$) with a 1:5 ($w/w$) CMC: PVA ratio is suitable for making patches. The correlation between the mechanical properties and the different materials was found using the simulation analysis as well as the force required for different dissolving microneedles (DMNs) to penetrate the skin, which significantly promoted the research progress of microneedle transdermal drug delivery.