Nanoparticle-functionalized microcapsules for in vitro delivery and sensing

Abstract

Inorganic nanoparticles such as magnetic nanoparticles, fl uorescent quantum dots, and plasmonic nanoparticles can be used as building blocks for designing multifunctional systems based on polymeric capsules. The properties of the inorganic nanoparticles hereby are harnessed to provide additional functionality to the polymer capsules. Biological applications towards in vitro sensing and delivery are discussed. Examples will be given in which magnetic nanoparticles are used to direct capsules with magnetic fi eld gradients, colloidal quantum dots are used to identify capsules via the formation of optical barcodes, and gold nanoparticles are used as light-controlled heat-sources for opening capsules and releasing macromolecules from their cavity upon optical excitation. This demonstrates that combination of inorganic nanoparticles and organic/polymeric molecules as carrier matrices allow for tailoring multifunctional hybrid particles for practical applications.

Targeting the Target Using Nanoparticles - A Review

“…Polymeric micelles are formed by self-assembly of block copolymers consisting of two or more polymer chains with different hydrophobicity [1].…”

“…Specifically, hydrophobic blocks form the core to minimize their exposure to aqueous surroundings whereas the hydrophilic blocks form the corona-like shell to stabilize the core through direct contact with water. This micelle structure provides an ideal drug delivery necessarily [1]. Dendrimers are members of a versatile, fourth new class of polymer architecture (i.e.…”

“…Size and charge are important parameters which affect interaction with cells. (iv) The PEM wall can be biodegradable or nondegradable, and its porosity can be tuned by the number of polyelectrolyte layers and by the PEM materials [1].…”

“…In this way, it is possible to direct and accumulates those objects at a designated target site. This concept has been successfully used, for example, for in vivo targeting of drug-loaded MNPs to tumor tissue [1]. As many MNPs can be loaded with each capsule, the resulting magnetic moment is rather high.…”

Intracellular delivery and sensing based on polyelectrolyte multilayer capsules

“…This means that with increasing numbers of layers the inner layers are more and more unaffected by hydration [23]. Concerning applications of capsules in biomedical fields, they can generally be divided into delivery and sensing applications [24,25]. A large size of the capsules can be of advantage in cell culture models, as large capsules are easily traceable with optical techniques.…”