Abstract: The present disclosure provides layer-by-layer compositions comprising a plurality of polymer bilayers. Each bilayer comprises a poly(N-vinylpyrrolidone) hydrogen-bonded a polyphenol (tannic acid) layer. In the compositions, at least one poly(N-vinylpyrrolidone) has conjugated thereon a plurality of manganoporphyrin moieties. The layer-by-layer compositions can be deposited on the cell aggregate surface or deposited on an underlying surface such as that of a silica core which, when removed creates a capsule having a hollow space for the addition of such as a therapeutic agent.

Abstract: The theranostic biocompatible microcapsules provided are efficient contrast enhanced imaging agents that combine Magnetic Resonance Imaging (MRI) with ultrasound-triggered drug release for real-time tracking and targeted delivery in vivo. The capsules are assembled via layer-by-layer deposition of the natural polyphenol tannic acid and poly(N-vinylpyrrolidone) with iron oxide nanoparticles incorporated in the capsule wall. The nanoparticle-modified capsules exhibit enhanced T1 and T2 MRI contrast in a clinical MRI scanner. Loaded with the an anticancer drug such as doxorubicin the capsules circulate in the blood stream for at least 48 hours, an improvement compared to non-encapsulated nanoparticles. High-intensity focused ultrasound results in targeted drug release with a 16-fold increase in the pharmacologically active agent localization in tumors compared to off-target organs.

Abstract: Micro-, and nano-scale capsules comprising neutral (uncharged) polymeric layers, layers associated by hydrogen bonding and methods for making such capsules. The capsules of the invention are layered upon a core particle using a layer-by layer-technique. The capsule walls of the capsules of the invention give a tailored response to external stimuli.

Abstract: Low molecular weight molecules are selectively released from a layered polymer film having a net excess charge by introducing at least one other type of molecule that binds reversibly to the film and thereby reduces the net excess charge. Oligomeric and polymeric molecules, whether synthetic or natural, are selectively and reversibly released from the layered polymer film in response to variation in ionic strength in the environment of the film. Such molecules are also selectively and reversibly released from the layered polymer film in response to changes in the pH in the environment of the film.