鞭毛/纤毛内在驱动机制启发的一体式管状机器人驱动器

鞭毛和纤毛独特的运动模式(如鞭毛的平面/螺旋波形式推进和纤毛的二维/三维不对称搏动)在众多生物的生命活动中起到至关重要的作用,这也启发了诸多仿生设计,尤其对于微型机器人系统。然而,与自然界中微生物能够从统一化的9+2轴丝生物结构中进化出多种运动模式不同的是,当前的仿生学仍然没有有效的工程策略去实现这样的智慧。在此,我们通过研究鞭毛和纤毛的内部结构及其内在驱动机制,推导出了一个统一的物理模型来描述微管弯曲及其所构建的宏观鞭毛/纤毛运动。基于该模型,我们进而提出了基于三通道的管状驱动概念,并相应地通过杆嵌入铸造工艺制造了一个三通道的管状驱动器。通过编程不同通道的驱动模式,这一管状驱动器不仅可以再现自然界中多样的二维及三维鞭毛/纤毛运动,还可以延展出更多的非对称纤毛搏动模式以实现低雷诺数下的有效推进。该研究加深了我们对微生物推进机制的理解,为仿生系统的设计提供了新灵感,并有望在广泛的工程领域中寻找到重要的应用场景。

Emerging non-antibody‒drug conjugates (non-ADCs) therapeutics of toxins for cancer treatment

The non-selective cytotoxicity of toxins limits the clinical relevance of the toxins.In recent years,toxins have been widely used as warheads for antibody-drug conjugates(ADCs)due to their eff-cient killing activity against various cancer cells.Although ADCs confer certain targeting properties to the toxins,low drug loading capacity,possible immunogenicity,and other drawbacks also limit the po-tential application of ADCs.Recently,non-ADC delivery strategies for toxins have been extensively investigated.To further understand the application of toxins in anti-tumor,this paper provided an over-view of prodrugs,nanodrug delivery systems,and biomimetic drug delivery systems.In addition,toxins and their combination strategies with other therapies were discussed.Finally,the prospect and challenge of toxins in cancertreatmentwerealso summarized.

Carrier-free highly drug-loaded biomimetic nanosuspensions encapsulated by cancer cell membrane based on homology and active targeting for the treatment of glioma

Nanosuspensions,as a new drug delivery system for insoluble drugs,are only composed of a drug and a small amount of stabilizer,which is dispersed in an aqueous solution with high drug-loading,small particle size,high dispersion,and large specific surface area.It can significantly improve the dissolution,bioavailability,and efficacy of insoluble drugs.In this study,paclitaxel nanosuspensions((PTX)NS)were prepared by an ultrasonic precipitation method,with the characteristics of simple preparation and easy repetition.With the help of a homologous targeting mechanism,a kind of glioma C6 cancer cell membrane(CCM)-coated(PTX)NS was developed and modified with DWSW peptide to obtain DWSW-CCM-(PTX)NS with the functions of BBB penetration and tumor targeting.The results showed that the cancer cell membrane could effectively camouflage the nanosuspensions so that it was not cleared by the immune system and could cross the blood-brain-barrier(BBB)and selectively target tumor tissues.Cell uptake experiments and in vivo imaging confirmed that the uptake of DWSW-CCM-(PTX)NS by tumor cells and the distribution in intracranial gliomas increased.Cytotoxicity test and in vivo anti-glioma studies showed that DWSW-CCM-(PTX)NS could significantly inhibit the growth of glioma cells and significantly prolong the survival time of glioma-bearing mice.Finally,the cancer cell membrane coating endowed the nanosuspensions with the biological properties of homologous adhesion and immune escape.This study provides an integrated solution for improving the targeting of nanosuspensions and demonstrates the encouraging potential of biomimetic nanosuspensions applicable to tumor therapy.

Mixed alkaline phosphatase/sphingomyelin monolayer at the air-buffer interface: phase behavior and morphology

The glycosylphosphatidyl inositol(GPI)-anchored proteins are localized on the outer of the plasma membrane and clustered in membrane microdomain known as lipid rafts. Among them, mammalian alkaline phosphatase(AP) is an enzyme widely distributed. So, it has important biological significance to study the combination of AP with lipid monolayer. In our work, the interaction between AP and sphingomyelin has been studied at the air-buffer interface as a biomimetic membrane system by the Langmuir film technique and atomic force microscopy. The surface pressure-area isotherm for the mixed alkaline phosphatase/sphingomyelin monolayer shown the presence of a transition from a liquid-expanded phase to the liquid-expanded/liquidcondensed coexist phase. And the surface compressional modulus suggested the mixed alkaline phosphatase/sphingomyelin monolayer has larger compressibility compared with the pure sphingomyelin monolayer. Besides, according to the micrographs, we inferred when combined with lipid monolayer at the air-buffer interface, the AP molecules formed polymer not multilayer or micelle. And, according to the limiting molecules area of AP, we inferred that 12 AP molecules formed a hexagon polymer unit.

Large-Size Honeycomb-Shaped and Iris-Like Liquid Crystal Elastomer Actuators

Nature is providing inspiration for researchers to mimic its functions or existing structures,which could remarkably promote the development of new materials.Here,a large-size honeycomb-shaped liquid crystal elastomer(LCE)actuator with LC orientation along the height of the honeycomb shape is built by combining magnetic field alignment and soft lithography technology.This homeotropic alignment allowed the height contraction of honeycomb and pore size expansion of hexagons in a reversible manner upon temperature variation.Therefore,this LCE actuator can be used as a structure for temperature-gated separation of particles.Another example is an iris-like LCE actuator,which has the capability of adjusting its aperture size with a temperature variation.Our approach provides a simple way to design customizable sophisticated LCE actuators for various potential applications.