Optimization of amine-rich multilayer thin films for the capture and quantification of prostate-specific antigen

Computational Design of a Functionalized Substrate for Capturing Nanoparticles with Specific Size and Shape

The efficient capture of nanoscopic particulates plays a key role in many scientific fields like filtration and fabrication of nanocomposites as well as biosensors. In this work, we design two types of nanosubstrates to capture the nanoparticle with specific property by using Brownian dynamics simulations. It is found that the substrate coated with copolymers (composed of nonspecific block and specific block) can be used to capture the nanoparticle with different sizes but its capture efficiency of nanoparticles with different shapes is very low. To overcome such problem, the other substrate containing shaped holes is also designed. By conducting a serial of control simulations, we find that the nonspecific polymers at the bottom and on the rim of the hole have great impact on the sensitive capture. The present study may provide some physical insights into the experimental design of nanodevices in real applications.

Stiffer but More Healable Exponential Layered Assemblies with Boron Nitride Nanoplatelets

Self-healing ability and the elastic modulus of polymeric materials may seem conflicting because of their opposite dependence on chain mobility. Here, we show that boron nitride (BN) nanoplatelets can simultaneously enhance these seemingly contradictory properties in exponentially layer-by-layer-assembled nanocomposites as both surface coatings and free-standing films. On one hand, embedding hard BN nanoplatelets into a soft hydrogen bonding network can enhance the elastic modulus and ultimate strength through effective load transfer strengthened by the incorporation of interfacial covalent bonding; on the other hand, during a water-enabled self-healing process, these two-dimensional flakes induce an anisotropic diffusion, maintain the overall diffusion ability of polymers at low loadings, and can be "sealing" agents to retard the out-of-plane diffusion, thereby hampering polymer release into the solution. A detailed mechanism study supported by a theoretical model reveals the critical parameters for achieving a complete self-healing process. The insights gained from this work may be used for the design of high-performance smart materials based on other two-dimensional fillers.

Liposome-Loaded Cell Backpacks

Cell backpacks, or micron-scale patches of a few hundred nanometers in thickness fabricated by layer-by-layer (LbL) assembly, are potentially useful vehicles for targeted drug delivery on the cellular level. In this work, echogenic liposomes (ELIPs) containing the anticancer drug doxorubicin (DOX) are embedded into backpacks through electrostatic interactions and LbL assembly. Poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA)n , and poly(diallyldimethylammonium chloride)/poly(styrene sulfonate) (PDAC/SPS)n film systems show the greatest ELIP incorporation of the films studied while maintaining the structural integrity of the vesicles. The use of ELIPs for drug encapsulation into backpacks facilitates up to three times greater DOX loading compared to backpacks without ELIPs. Cytotoxicity studies reveal that monocyte backpack conjugates remain viable even after 72 h, demonstrating promise as drug delivery vehicles. Because artificial vesicles can load many different types of drugs, ELIP containing backpacks offer a unique versatility for broadening the range of possible applications for cell backpacks.