Layer-by-layer nanostructured protein loaded nanoparticles: A feasibility study using lysozyme as model protein and chitosan as coating material

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

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.

Cellular level evaluation and lysozyme adsorption regulation of bimodal nanoporous silica

The present work initially evaluated cellular toxicity and uptake of our previous biomimetic bimodal nanoporous silica (B-BNS) and applied it as lysozyme adsorbent, which aimed to study potential ability of B-BNS as antitumor biological macromolecules carrier. To highlight the advantage of bimodal mesopores, comparisons were made between single mesoporous silica nanoparticles (S-MSN) and B-BNS. Cell evaluation work was conducted using MCF-7 cells and lysozyme adsorption process was studied with pH and lysozyme concentration as independent variables. The results indicated that the toxicity of S-MSN and B-BNS on MCF-7 cell could be neglected. In addition, S-MSN and B-BNS had the ability to be uptaken into cells and even nucleus evidenced by inverted fluorescence microscope and confocal laser scanning microscopic. Compared to S-MSN, B-BNS adsorbed larger amount of lysozyme due to its bimodal mesopores. Lysozyme adsorption was favorably approximated by the pseudo-second order model. The equilibrium data of lysozyme adsorption were fitted to the Langmuir isotherm model much better than the Freundlich isotherm model, suggesting that lysozyme adsorption on B-BNS via the monolayer adsorption process. Overall, B-BNS can be considered as good antitumor biological macromolecules carrier.