Silver Alginate Hydrogel Micro- and Nanocontainers for Theranostics: Synthesis, Encapsulation, Remote Release, and Detection

Abstract

We have designed multifunctional silver alginate hydrogel microcontainers referred to as loaded microcapsules with different sizes by assembling them via a template assisted approach using natural, highly porous calcium carbonate cores. Sodium alginate was immobilized into the pores of calcium carbonate particles of different sizes followed by cross-linking via addition of silver ions, which had a dual purpose: on one hand, the were used as a cross-linking agent, albeit in the monovalent form, while on the other hand they have led to formation of silver nanoparticles. Monovalent silver ions, an unusual cross-linking agent, improve the sensitivity to ultrasound, lead to homogeneous distribution of silver nanoparticles. Silver nanoparticles appeared on the shell of the alginate microcapsules in the twin-structure as determined by transmission electron microscopy. Remote release of a payload from alginate containers by ultrasound was found to strongly depend on the particle size. The possibility to use such particles as a platform for label-free molecule detection based on the surface enhanced Raman scattering was demonstrated. Cytotoxicity and cell uptake studies conducted in this work have revealed that microcontainers exhibit nonessential level of toxicity with an efficient uptake of cells. The above-described functionalities constitute building blocks of a theranostic system, where detection and remote release can be achieved with the same carrier.

Impact of Nanocapsules on Red Blood Cells Interplay Jointly Assessed by Optical Tweezers and Microscopy

“…Nowadays, there are numerous delivery systems such as: natural biological vehicles (such as bacteria and viruses [1,2], various cell types including red blood cells (RBCs) [3][4][5], immune cells [6,7], stem cells [8][9][10][11] and manufactured carriers (liposomes [12], micelle [13], polymeric capsules [14][15][16][17], polymeric complexes [18][19][20][21]). Polymeric nanocapsules (NCs) are a promising system of natural carriers for targeted drug delivery because of their low cytotoxicity, shell flexibility, and high in vivo stability [22][23][24][25][26].…”

Probing Internalization Effects and Biocompatibility of Ultrasmall Zirconium Metal-Organic Frameworks UiO-66 NP in U251 Glioblastoma Cancer Cells

“…The synthesis and application of nano-objects to be employed for therapeutic, pharmacological and diagnostic purposes has been rapidly growing [ 4 , 5 ]. Metallic nanoparticles (NPs), (i.e., plasmonic gold nanoclusters, silver NP, ferrite or magnetite superparamagnetic NP) of very small size are currently used as theranostic agents in living cells for a large number of diseases [ 6 , 7 , 8 ]. Nanomaterials are able to offer an efficient drug delivery by means of cellular internalization after encapsulation or surface attachment of the drugs.…”

Polymeric and Lipid Membranes—From Spheres to Flat Membranes and vice versa

“…Ultrasound offers an easy and fast way of inducing release from multilayered capsules and may be of interest to the biomedical field, for example, in topical application of ultrasound after subcutaneous injection of capsules. Ultrasound was used to destroy polyelectrolyte multilayer capsules as well as hydrogel capsules [ 36 ] based on PS (polystyrene) and CaCO 3 cores. In this sense, nanoparticles were used to increase the density of microcapsule shells and ultrasound served as a trigger to release encapsulated material.…”