Owing to their autonomous movement characteristics, micromotors can perform various tasks that traditional drug‐delivery carriers fail to perform. The development of adaptable, highly efficient, functional micromotors has become the primary research goal in biomedical field. Micromotors modified with polymers can exhibit strong propulsion ability and unique performance in a complex biological environment, facilitating their application to various complex environments. Herein, different micromotor designs based on natural and synthetic polymers are discussed and the role of polymers in the structure and performance of micromotors is focused on. Overall, the polymer‐modified micromotors can facilitate new developments, particularly in biomedical applications, such as drug delivery and biological detection.

Chitosan with pH sensitivity and biocompatibility was selected to prepare chitosan nanoparticle-stabilized Pickering emulsion (CSPE). The flexibility of CSPE enables stress deformation when in contact with cell membranes, thereby mimicking the deformability of natural pathogens and facilitating their efficient uptake by cells. In the acidic environment of lysosomes, the amino groups of chitosan molecules are protonated, and the water solubility increases. CSPE transforms from particle-stabilized to polymer chain-stabilized, its subsequent swelling and proton accumulation lead to lysosome rupture. The experimental results evaluating CSPE as an adjuvant shows that CSPE could efficiently load antigens, promote endocytosis and antigen cross-presentation, recruit antigen-presenting cells at the injection site, boost T-cell activation, and enhance both humoral and cellular immune responses. In the prophylactic and therapeutic tumor models of E.G7-OVA lymphoma and B16-MUC1 melanoma, CSPE significantly inhibited tumor growth and prolonged the survival of mice. In summary, antigenic lysosomal escape resulted from the chitosan molecular state transition is the key to the enhancement of cellular immunity by CSPE, and CSPE is a promising vaccine adjuvant.

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The title compound, C18H31Cl3N2O5, an enanti­opure dipeptide trichloro­ethyl ester, is one of two starting fragments in the synthesis of cyclo­sporin O analogs. In the crystal structure, mol­ecules are linked by N—H⋯O=C hydrogen bonds, forming a β‐spiral assembly along the c axis.