A Comparison of Chitosan, Mesoporous Silica and Poly(lactic-co-glycolic) Acid Nanocarriers for Optimising Intestinal Uptake of Oral Protein Therapeutics

Abstract

Efficacious oral delivery of therapeutic proteins remains challenging and nanoparticulate approaches are gaining interest for enhancing their permeability. In this study, we explore the ability for three comparably sized nanocarriers, with diverse physicochemical properties [i.e., chitosan (CSNP), mesoporous silica nanoparticles (MSNP) and poly(lactic-co-glycolic) acid (PLGA-NP)], to successfully facilitate epithelial uptake of a model protein, ovalbumin (OVA). We report the effect of nanoparticle surface chemistry and nanostructure on protein release, cell toxicity and the uptake mechanism in a Madin Darby Canine Kidney (MDCK) cell model of the intestinal epithelium. All nanocarriers exhibited bi-phasic OVA release kinetics with sustained and incomplete release after 4 days, and more pronounced release from MSNP than either polymeric nanocarriers. CSNP and MSNP displayed the highest cellular uptake, however CSNP was prone to significant dose-dependent toxicity attributed to the cationic surface charge. Approximately 25% of MSNP uptake was governed by a clathrin-independent endocytic mechanism, while CSNP and PLGA-NP uptake was not controlled via any endocytic mechanisms investigated herein. Furthermore, endosomal localisation was observed for CSNP and MSNP, but not for PLGA-NP. These findings may assist in the optimal choice and engineering of nanocarriers for specific intestinal permeation enhancement for oral protein delivery.

Cellular Uptake and Transport Mechanism Investigations of PEGylated Niosomes for Improving the Oral Delivery of Thymopentin

“…Cellular uptake was also partially blocked by 10 µg/mL Chlorpromazine, indicating the involvement of clathrin-mediated endocytosis. This corresponds to the results of other studies in which lipid-based nanocarriers mainly follow caveolae- or clathrin-mediated endocytosis for cellular uptake in intestinal epithelial membranes [ 49 , 50 , 51 , 52 ].…”

“…Cellular uptake was also partially blocked by 10 µg/mL Chlorpromazine, indicating the involvement of clathrin-mediated endocytosis. This corresponds to the results of other studies in which lipid-based nanocarriers mainly follow caveolae-or clathrin-mediated endocytosis for cellular uptake in intestinal epithelial membranes [49][50][51][52]. To investigate whether active cellular uptake mechanisms were involved for TP5 and its formulation, inhibitors that block adsorptive-mediated endocytosis, clathrin-mediated endocytosis and caveolae-mediated endocytosis or a reduction in temperature were used.…”

“…On reaching 80% confluence, the culture medium was replaced with HBSS (2 mL). After 30 min of incubation at 37 • C, the medium was replaced with 1 mL TP5 solution with different concentrations (5,10,50,100,200,500, and 1000 µg/mL in HBSS) and TP5-PEG-niosomes (1 mg TP5 in 0.01, 0.05, 0.10, 1.00, 2.00, and 5.00 × 10 12 numbers niosomes per mL in HBSS) and incubated for 4 h at 37 • C to investigate the effect of drug and niosome concentration on TP5 cellular uptake. For time-dependent cellular uptake experiments, the cells were incubated for 0.5, 1, 2, 3, 4 and 5 h at 37 • C, respectively.…”

“…Cellular Uptake Mechanisms of TP5 and TP5-PEG-Niosomes One of the mechanisms for cellular uptake depends on concentration. To carry out a drug-concentration-dependent cellular uptake study, aliquots of 2 mL TP5 of different concentrations (10,50,100,200, 500 and 1000 µg/mL) in HBSS were added into the dish and incubated for 60 min in triplicate. To carry out a noisome-concentration-dependent cellular uptake study, 2 mL TP5-PEG-niosomes of different niosome numbers (0.01, 0.05, 0.10, 1.00, 2.00, and 5.00 × 10 12 /mL measured by NanoSight NS300 (Malvern Instruments Ltd., Worcestershire, UK) and prepared by series dilution) in HBSS was added into the dish and incubated for 4 h in triplicate.…”

Encapsulation of bioactive peptides: a strategy to improve the stability, protect the nutraceutical bioactivity and support their food applications

“…36 In the matter of materials used for encapsulation of bioactive peptides, the most common encapsulation materials used in the above mentioned methods include polysaccharides (e.g., MD, chitosan, and gum arabic), lipids (e.g., phosphatidylcholine, phospholipids), and to a lesser extent, proteins (e.g., whey protein isolate). The polysaccharides are generally recognized as safe (GRAS) established by the Food and Drug Administration (FDA) 37,38 and have low cost, low viscosity at high solids ratios, and are biodegradable. 39 Therefore, these characteristics make them suitable materials for encapsulation methods.…”