Formulation of Next‐Generation Multicompartment Microcapsules by Reversible Electrostatic Attraction

Abstract

The combination of several active substances into one carrier is often limited due to solubility, stability and phase-separation issues. These issues have been addressed by an innovative capsule design, in which nanocapsules are assembled on the microcapsule surface by electrostatic forces to form a pH-responsive hierarchical capsule@capsule system. Here, melamine-formaldehyde (MF) microcapsules with a negative surface charge were synthesized and coated with a novel MF-polyethyleneimine (PEI) copolymer to achieve a positive charge of ζ = + 28 mV. This novel coating procedure allows the electrostatic assembly of negatively charged polyl-lactide (PLLA, ζ = À 19 mV) and poly-(lactide-co-glycolide) (PLGA, ζ = À 56 mV) nanocapsules on the microcapsule surface. Assembly studies at pH 7 gave a partial surface coverage of PLLA nanocapsules and full surface coverage for PLGA nanocapsules. The pH-responsive adsorption and desorption of nanocapsules was shown at pH 7 and pH 3.

A decade of developing applications exploiting the properties of polyelectrolyte multilayer capsules

“…14, was fabricated by absorbing negatively charged nanocapsules onto a positively charged melamine-formaldehyde-polyethyleneimine microcapsule surface. 365 This pH-responsive assembly and disassembly of nanocapsule@microcapsules was shown at pH|7 and pH|3. Application of microcapsules regarding applications of artificial organelles and cell mimicry was discussed in light of broader biomedical applications.…”

Adsorption of Fragrance Capsules onto Cellulose Nano- and Micro-Cellulose Fibers in Presence of Guar Biopolymers

“…A solution to this issue came from the encapsulation technology [16], permitting long-lasting perfume activity due to a controlled fragrance release. Recently, a major effort has been devoted to the development of such micron-sized capsules [11,[17][18][19][20][21][22][23][24][25][26][27][28][29]. Synthetic or natural polymers, inorganic materials, and polymer-inorganic composites have been identified as chemical compounds for capsule scaffolds [3,18].…”

“…Our goal here is to provide a straightforward protocol to quickly and simply identify the strength of interaction between the fragrance capsules and CNCs and determine the role of the other softener ingredients in this interaction. Here, we use negatively charged melamine-based capsules [24] and we monitor their interaction on cellulose alone, in the presence of a benchmark softener containing surfactant vesicles [1,2]. Furthermore, we harness a newly developed conditioner with a lower environmental impact due to the reduced esterquat surfactant content.…”

Fabrication of Dual Self-Healing Multifunctional Coating Based on Multicompartment Microcapsules

“…Multicompartment microcapsules are capable of integrating multiple functions in different microcontainers with a single material. − Design and preparation of multicompartment microcapsules can store PCMs and release active materials, while producing micro- or nanoscale hierarchical surface structures. Thus far, several existing studies on the fabrication of multicompartment microcapsules have been conducted. − For instance, Neumann et al fabricated a multicompartment microcapsule by absorbing electrostatic attraction of negatively charged nanocapsules onto positively charged melamine-formaldehyde-polyethyleneimine microcapsules . Lay-by-layer self-assembly techniques had been adopted to prepare multicompartment microcapsules.…”