Protease degradable tethers for controlled and cell-mediated release of nanoparticles in 2- and 3-dimensions

Abstract

Strategies to control the release rate of bioactive signals from tissue engineering scaffolds are essential for tissue regeneration and tissue engineering applications. Here we report on a strategy to achieve temporal control over nanoparticle release from biomaterials using cell-secreted proteases. This cell-triggered release approach utilizes peptides that are degraded by matrix metalloproteinases (MMPs) at different rates to immobilize nanoparticles directly to the biomaterial surface. Thus, the peptide-immobilized nanoparticles are released with temporal control through the action of cellreleased MMPs. We found that release rates of peptide-immobilized nanoparticles were a function of peptide sensitivity to proteases, the number of tethers between the nanoparticle and the surface and the concentration of proteases used to induce release. Cellular internalization of the peptideimmobilized nanoparticles was also a function of the peptide sensitivity to proteases, the number of tethers between the nanoparticle and the surface and MMP expression profile of the cells. Similar trends were observed for peptide-immobilized nanoparticles inside micro-porous hydrogels, indicating protease sensitive tethers are effective in controlling release rate and internalization of nanoparticles. Such a temporal delivery strategy of nanoparticles loaded with therapeutic payloads (e.g. protein, DNA, siRNA) can be an ideal means to guide tissue formation.

Stimuli-sensitive intrinsically disordered protein brushes

“…The extensive suite of proteases and protease recognition sites-any of which could be introduced into the sequence at one or more arbitrary positions-should provide a versatile toolbox for controlling IDP brush properties in a dynamic and specific manner. Analogous enzymatically addressable materials have been explored for a variety of applications such as payload delivery 42 , diagnostic monitoring 43 and ligand presentation [44][45][46] . Although much effort has been focused on understanding the biological function of endogenous IDPs, our study suggests that these proteins represent an untapped resource for biomaterial design.…”

Enhancing regenerative approaches with nanoparticles

“…For example, in a study by Tokatlian et al nanoparticles were immobilized to a biomaterial through the use of matrix metalloproteinases (MMPs) sensitive linkers. In this way, cell-secreted MMPs could release the nanoparticles from the biomaterial in a temporally controlled manner [68]. External stimuli such as light have also been used to induce remotely controlled biomolecule release from a hydrogel-nanoparticle hybrid scaffold [69].…”

“…The advantage of using such particles is that the silica matrix chemically and physically confines the fluorescent dye while providing an easy-to-functionalize surface for bioconjugation. Also combinations of organic-inorganic nanocarriers have been investigated to merge the theranostic capabilities of metal oxides with the biocompatibility and drug delivery capacity of polymers [68]. rsif.royalsocietypublishing.org J. R. Soc.…”

Preparation of Biodegradable Gelatin Nanospheres with a Narrow Size Distribution for Carrier of Cellular Internalization of Plasmid DNA

“…Since MSC are non-phagocytic cells, it is known that the cells cannot take up larger particles [37,38]. In this study, the size dependence of spheres internalization was observed (Fig.…”