Functional PLGA NPs for Oral Drug Delivery: Recent Strategies and Developments

Abstract

This article presents the potential of PLGA nanoparticles for the oral administration of drugs. Different strategies are used to improve oral absorption of these nanoparticles. These strategies are based on modification of nanoparticle surface properties. They can be achieved either by coating the nanoparticle surface with stabilizing hydrophilic bioadhesive polymers or surfactants, or by incorporating biodegradable copolymers containing a hydrophilic moiety. Some substances such as chitosan, vitamin E, methacrylates, lectins, lecithins, bile salts and RGD molecules are employed for this purpose. Of especial interest are nanoparticles production methods and, in order to improve oral bioavailability, the mechanism of each additive.

Enhancement of oral bioavailability of cyclosporine A: comparison of various nanoscale drug-delivery systems

“…42 Nevertheless, it is well known that adsorptive endocytosis is initiated by electrostatic forces, by which positively charged particulate vehicles can readily adhere to the negatively charged cell surface of intestinal mucosa. 43 In our study, PLGA NPs were prepared without any chemical modification and displayed negative charge. Meanwhile, it is generally believed that endocytosis of intestinal epithelial is a slow and infrequent process compared with passive transport.…”

Quantification of Particle-Conjugated or Particle-Encapsulated Peptides on Interfering Reagent Backgrounds

“…However, common reagents for conjugating or retrieving peptides or proteins to or from particles interfere with these assays, leading to inaccurate measurements (11,12). 1-ethyl-3-(-3-dimethylaminopropyl)carbodiimide (EDC) (12–14) is often utilized for the bioconjugation of peptides or proteins to particles (15). We measured the interference of EDC with the BCA, Coomassie Plus and 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA) assays.…”

Design of Insulin-Loaded Nanoparticles Enabled by Multistep Control of Nanoprecipitation and Zinc Chelation

“…Relevant to oral delivery, NPs can be easily prepared from a variety of materials, targeting ligands on NPs can facilitate therapeutics to cross the epithelial barrier 21 , and NPs can protect encapsulated and adsorbed therapeutics from pH changes and enzymatic degradation in the gastrointestinal tract 21, 24-25 . Some proteins that have been incorporated in polymeric NP-based drug delivery systems include tetanus toxoid 26 , insulin 27 , and interleukin 2 (IL-2) 28 .…”

“…NPs prepared from a variety of materials such as chitosan, gelatin, poly-alkyl-cyano-acrylates, dextran and polycaprolactone have been explored for oral insulin delivery 19-21, 29 . However, PLGA-PEG NPs and poly (lactic acid)– b –poly (ethylene glycol) (PLA-PEG) NPs are advantageous in that they have been extensively studied as protein delivery carriers because of their biodegradability and biocompatibility, well-established safety in clinical trials, tunable surface properties for targeted delivery, and their capability to protect the protein drug from pH and proteolytic enzymes 22, 30-31 .…”