Layer-by-Layer Cell Encapsulation for Drug Delivery: The History, Technique Basis, and Applications

Abstract

The encapsulation of cells with various polyelectrolytes through layer-by-layer (LbL) has become a popular strategy in cellular function engineering. The technique sprang up in 1990s and obtained tremendous advances in multi-functionalized encapsulation of cells in recent years. This review comprehensively summarized the basis and applications in drug delivery by means of LbL cell encapsulation. To begin with, the concept and brief history of LbL and LbL cell encapsulation were introduced. Next, diverse types of materials, including naturally extracted and chemically synthesized, were exhibited, followed by a complicated basis of LbL assembly, such as interactions within multilayers, charge distribution, and films morphology. Furthermore, the review focused on the protective effects against adverse factors, and bioactive payloads incorporation could be realized via LbL cell encapsulation. Additionally, the payload delivery from cell encapsulation system could be adjusted by environment, redox, biological processes, and functional linkers to release payloads in controlled manners. In short, drug delivery via LbL cell encapsulation, which takes advantage of both cell grafts and drug activities, will be of great importance in basic research of cell science and biotherapy for various diseases.

Precision polymer nanofibers with a responsive polyelectrolyte corona designed as a modular, functionalizable nanomedicine platform

“…Polyelectrolyte materials have found numerous applications both inside and outside biology, from use in water treatment and purification, 1 the controlled wetting of surfaces 2 or as ion exchange membranes in fuel cells, 3 to uses in medical implant coatings, 4 nucleic acid delivery, 5 antimicrobials 6 and bioelec-tronics. 7 In particular, they have promising lubrication properties that are useful for anti-fouling coatings, 8 such as those used for medical implants, 4 whilst their bioadhesion properties allow them to encapsulate cells for drug delivery, 9 as well as making them potentially useful antimicrobial agents. 6 One of the most promising applications of polyelectrolytes is the delivery of therapeutic nucleic acids, which remains a key challenge that hampers the development of new treatments for a plethora of diseases from COVID-19 to cancer.…”

A redox‐reactive delivery system via neural stem cell nanoencapsulation enhances white matter regeneration in intracerebral hemorrhage mice

“…LbL nanoencapsulation could be established through different interactions 23 . Our previous studies coated gelatin and alginate on NSCs to deliver insulin‐like growth factor‐1; however, the electrostatic force‐based structure was relatively weak and unstable.…”

Chitosan-Based Biomaterials: Insights into Chemistry, Properties, Devices, and Their Biomedical Applications

“…The use of entire aqueous solutions and the mild processing conditions behind the fabrication of the LbL nanoassemblies have turned this technology into a suitable, cytocompatible methodology to functionalize animate and dynamic living cell surfaces, including single cells and cell aggregates [ 284 , 285 , 286 , 287 , 288 ]. In fact, probiotic microorganisms have been encapsulated in CHT/ALG multilayers to protect them from the gastro-intestinal microbiome and enhance their delivery, adhesion and growth in vivo ( Figure 21 a) [ 289 ].…”