The AF488 dye also served as a model for potential hydrophilic therapeutic compounds that could be encapsulated for bolus cutaneous delivery upon dissolution of the PAA matrix in vivo.
To resolve this challenge, polymeric and inorganic nanoparticles, liposomes, micelles and phospholipid complexes have been used to encapsulate them for delivery.
Researchers have reported dietary delivery of RNA or other molecules, encapsulated, for example, in various polysaccharide shells [ 76, 77] or in tumor cell-derived exosomes [ 78] or other vesicles [ 79, 80].
Targeted encapsulated drug delivery using NPs is more effective for improved bioavailability, minimal side effects, decreased toxicity to other organs, and is less costly.
Moreover, it might facilitate development of new antiinflammatory therapies, for example, encapsulated delivery of cortisone to the site of inflammation to take advantage of local 11β-HSD1 actovity to generate cortisol within the tissue in which it will be of most benefit, thus limiting the adverse metabolic effects of whole-body exposure to exogenous synthetic glucocorticoids.
However, for targeting to and accumulating in tumors, especially brain tumors, it is essential that QDs are conjugated with ligands or are encapsulated with target delivery systems.
On the other hand, growth factors could also be physically encapsulated in the delivery system, and they can be released from synthetic extracellular matrix to target specific cell populations [ 103]; however, none has been evaluated for ocular applications.
The use of chitosan as the wall of microcapsule designed for delivery of encapsulated celecoxib is reported.
Liposomes and polymersomes are generally used as carriers for encapsulating compounds, in particular drugs for delivery.
PEM capsules composed of biodegradable polyelectrolytes are fabricated for intracellular delivery of encapsulated cargo (for example peptides, enzymes, DNA, and drugs) through gradual biodegradation of the shell components.
