Search

The dynamics modeling and trajectory optimization of a segmented linkage cable-driven hyper-redundant robot (SL-CDHRR) become more challenging, since there are multiple couplings between the active cables, passive cables, joints and end-effector. To deal with these problems, this paper proposes a dynamic modeling and trajectory tracking control methods for such type of CDHRR, i.e., SL-CDHRR. First, the multi-coupling kinematics equation (i.e., cable-joint-end) of the hyper-redundant robot is derived. Then, according to the transmission characteristics of the hybrid active/passive segmented linkage, the dynamic equation of series–parallel coupling is derived. It consists of parallel-active dynamics and series-passive dynamics. Furthermore, using the tension of active cables and the pose of the end-effector as optimization indicators, a trajectory tracking framework was constructed by the combination of dynamic feedforward control and PD control. The multi-objective particle swarm optimization method is used to achieve the simultaneous optimization of the energy indicator and control accuracy indicator during the trajectory tracking process. Finally, a MATLAB/SimMechanics co-simulation system is built, and the proposed methods are verified by the built co-simulation system.

Background The combination of berberine (BER) and curcumin (CUR) has been verified with ameliorative effects on non-alcohol fatty liver disease (NAFLD). However, discrepant bioavailability and biodistribution of BER and CUR remained an obstacle to achieve synergistic effects. Multilayer nanovesicles have great potential for the protection and oral delivery of drug combinations. Therein lies bile salts inserted liposomes, named as bilosomes, that possesses long residence time in the gastrointestinal tract (GIT) and permeability across the small intestine. Diethylaminoethyl dextran (DEAE-DEX) is generally used as an outside layer on the nanovesicles to increase the mucinous stability and promote oral absorption. Herein, we developed a DEAE-DEX-coated bilosome with BER and CUR encapsulated (DEAE-DEX@LSDBC) for the treatment of NAFLD. Results DEAE-DEX@LSDBC with 150 nm size exhibited enhanced permeation across mucus and Caco-2 monolayer. In vivo pharmacokinetics study demonstrated that DEAE-DEX@LSDBC profoundly prolonged the circulation time and improved the oral absorption of both BER and CUR. Intriguingly, synchronized biodistribution of BER and CUR and highest biodistribution at liver was achieved by DEAE-DEX@LSDBC, which contributed to the optimal ameliorative effects on NAFLD. It was further verified to be mainly mediated by anti-oxidation and anti-inflammation related pathways Conclusion DEAE-DEX coated bilosome displayed promoted oral absorption, prolonged circulation and synchronized biodistribution of BER and CUR, leading to improved ameliorative effects on NAFLD in mice, which provided a promising strategy for oral administration of drug combinations. Graphic abstract

Acetylshikonin (AS) has demonstrated antitumor potential. However, the development of therapeutic applications utilizing AS is inhibited by its poor solubility in water. In the present work, polyamidoamine (PAMAM) dendrimers and their PEGylated derivatives were employed to increase the solubility of AS. A distinct color transition was observed during the encapsulation of AS suggesting strong intermolecular forces between PAMAM and AS. Ultraviolet-visible, high-performance liquid chromatography, and (1)H NMR were used to verify the interaction between PAMAM and AS. The maximum amount of combined AS to each PAMAM molecule was determined. The cytotoxicity of AS nanoparticles was evaluated against leukemia (K562) and breast cancer (SK-BR-3) cell lines; the AS nanoparticles were shown to effectively inhibit tumor cells.