Phase-transited lysozyme nanofilm with co-immobilized copper ion and heparin as cardiovascular stent multifunctional coating.

Cardiovascular metal stents have shown potential in the treatment of coronary artery disease using percutaneous coronary intervention. However, thrombosis, endothelialization, and new atherosclerosis after stent implantation remain unsolved problems. Herein, a multifunctional coating material based on phase-transited lysozyme was developed to promote stent endothelialization and simultaneously reduce thrombus events by embedding moieties of heparin and co-immobilized copper ions for in-situ catalyzing nitric oxide (NO) generation. The lysozyme-based biomimetic coating is compatible with blood and enables facile loading and sustainable release of copper ions to produce NO with donors via catalytic reaction. The novel coating strategy displayed several bio-effects of anti-thrombosis; it synergistically promoted endothelial cell growth and inhibited smooth muscle cell growth. Thus, this systemic in vitro study will provide a foundation for developing multifunctional cardiovascular stents in clinical settings.

Lactate Efflux Inhibition by Syrosingopine/LOD Co-Loaded Nanozyme for Synergetic Self-Replenishing Catalytic Cancer Therapy and Immune Microenvironment Remodeling.

An effective systemic mechanism regulates tumor development and progression; thus, a rational design in a one-stone-two-birds strategy is meant for cancer treatment. Herein, a hollow Fe3 O4 catalytic nanozyme carrier co-loading lactate oxidase (LOD) and a clinically-used hypotensor syrosingopine (Syr) are developed and delivered for synergetic cancer treatment by augmented self-replenishing nanocatalytic reaction, integrated starvation therapy, and reactivating anti-tumor immune microenvironment. The synergetic bio-effects of this nanoplatform stemmed from the effective inhibition of lactate efflux through blocking the monocarboxylate transporters MCT1/MCT4 functions by the loaded Syr as a trigger. Sustainable production of hydrogen peroxide by catalyzation of the increasingly residual intracellular lactic acid by the co-delivered LOD and intracellular acidification enabled the augmented self-replenishing nanocatalytic reaction. Large amounts of produced reactive oxygen species (ROS) damaged mitochondria to inhibit oxidative phosphorylation as the substituted energy supply upon the hampered glycolysis pathway of tumor cells. Meanwhile, remodeling anti-tumor immune microenvironment is implemented by pH gradient reversal, promoting the release of proinflammatory cytokines, restored effector T and NK cells, increased M1-polarize tumor-associated macrophages, and restriction of regulatory T cells. Thus, the biocompatible nanozyme platform achieved the synergy of chemodynamic/immuno/starvation therapies. This proof-of-concept study represents a promising candidate nanoplatform for synergetic cancer treatment.

A flocking algorithm for multi-agent systems with connectivity preservation under hybrid metric-topological interactions.

In this paper, we propose a connectivity-preserving flocking algorithm for multi-agent systems in which the neighbor set of each agent is determined by the hybrid metric-topological distance so that the interaction topology can be represented as the range-limited Delaunay graph, which combines the properties of the commonly used disk graph and Delaunay graph. As a result, the proposed flocking algorithm has the following advantages over the existing ones. First, range-limited Delaunay graph is sparser than the disk graph so that the information exchange among agents is reduced significantly. Second, some links irrelevant to the connectivity can be dynamically deleted during the evolution of the system. Thus, the proposed flocking algorithm is more flexible than existing algorithms, where links are not allowed to be disconnected once they are created. Finally, the multi-agent system spontaneously generates a regular quasi-lattice formation without imposing the constraint on the ratio of the sensing range of the agent to the desired distance between two adjacent agents. With the interaction topology induced by the hybrid distance, the proposed flocking algorithm can still be implemented in a distributed manner. We prove that the proposed flocking algorithm can steer the multi-agent system to a stable flocking motion, provided the initial interaction topology of multi-agent systems is connected and the hysteresis in link addition is smaller than a derived upper bound. The correctness and effectiveness of the proposed algorithm are verified by extensive numerical simulations, where the flocking algorithms based on the disk and Delaunay graph are compared.

Distributed Algorithm for Voronoi Partition of Wireless Sensor Networks with a Limited Sensing Range.

For Wireless Sensor Networks (WSNs), the Voronoi partition of a region is a challenging problem owing to the limited sensing ability of each sensor and the distributed organization of the network. In this paper, an algorithm is proposed for each sensor having a limited sensing range to compute its limited Voronoi cell autonomously, so that the limited Voronoi partition of the entire WSN is generated in a distributed manner. Inspired by Graham's Scan (GS) algorithm used to compute the convex hull of a point set, the limited Voronoi cell of each sensor is obtained by sequentially scanning two consecutive bisectors between the sensor and its neighbors. The proposed algorithm called the Boundary Scan (BS) algorithm has a lower computational complexity than the existing Range-Constrained Voronoi Cell (RCVC) algorithm and reaches the lower bound of the computational complexity of the algorithms used to solve the problem of this kind. Moreover, it also improves the time efficiency of a key step in the Adjust-Sensing-Radius (ASR) algorithm used to compute the exact Voronoi cell. Extensive numerical simulations are performed to demonstrate the correctness and effectiveness of the BS algorithm. The distributed realization of the BS combined with a localization algorithm in WSNs is used to justify the WSN nature of the proposed algorithm.