Controlled Release of DNA from Self‐Degrading Microcapsules

Abstract

Self‐disintegrating microcapsules were prepared by encapsulating a highly active mix of proteases (Pronase®) into biodegradable polyelectrolyte shells. Pronase was captured by micron‐sized calcium carbonate particles that were subsequently embedded into onion‐like shells of poly(L‐arginine) and poly(L‐aspartic acid). EDTA treatment was used to extract the calcium carbonate constituents from the resulting core‐shell particles. As a consequence, Pronase was released into the capsule interior and started to digest the surrounding polyelectrolyte shell. Lifetimes of such self‐disintegrating capsules could be successfully adjusted to seconds, hours or days by varying the amount of encapsulated Pronase. The enzyme‐mediated, sustained release of encapsulated DNA is presented as a prospective application in drug delivery.magnified image

Microcapsules functionalized with neuraminidase can enter vascular endothelial cells in vitro

“…This can be achieved if the size of the cargo is significantly bigger than that of the enzyme [35]. When the size of the drug is similar to that of the enzyme, there will be leakage of the drug before capsules enter the cell.…”

Intracellular delivery and sensing based on polyelectrolyte multilayer capsules

“…they are not passed on in a fifty-fifty manner [30,31]. Capsules can be filled with various cargos for delivery, among them drugs, genetic material like desoxyribonucleic acid (DNA) or ribonucleic acid (RNA), or proteins [12,[32][33][34][35][36][37]. The experimental challenges lie in the difficulties to encapsulate certain cargos in a sufficient way, but also in problems to release the cargo at the desired target site.…”

Polymeric multilayer capsules delivering biotherapeutics

“…So far the following biotherapeutics have been encapsulated in CaCO 3 templated PMLC: dextran, a-lactalbumin, lysosyme, horseradish peroxidise, glucose oxidase, catalase, ovalbumin, bovie serum albumin, achymotrypsin, insulin DNA and pronase. [15,17,18,[24][25][26][27][28] A third category of template particles that have gathered considerable attention in literature are hydrogel beads. Hydrogels are strongly hydrated 3D networks which, due to their aqueous environment offer good preservation of the biotherapeutics' bioactivity upon encapsulation.…”

“…templates by EDTA has been shown by the Sukhorukov group. [28] Alternatively to the use of electrostatic interactions, the Caruso group has elaborated on the use of hydrogen bonding to incorporate oligonucleotides either in the cavity or in the wall of polyelectrolyte capsules. Amine modified mesoporous silica microspheres could accumulate oligonucleotides through electrostatic interactions into their pores and multilayer build-up of hydrogen bonded poly(methacrylic acid) and poly(vinylpyrrolidone) followed by etching of the silica core templates yielded hollow capsules with oligonucleotides stably encapsulated within their cavity.…”