Nanoparticles permeation-enhancing

In spite of these formidable challenges, the attractiveness of oral route has fueled the exploration of an incredibly diverse set of strategies to deliver proteins and peptides and the subject has been exhaustively reviewed. The various approaches include permeation enhancers, enzyme inhibitors, mucoadhesives, multifunctional matrices that simultaneously incorporate the above strategies, enteric coatings that offer protection from the acidic environment of the stomach, encapsulation (liposomes, microspheres, and nanoparticles), pH-sensitive polymers, microemulsions, carriers (delivery agents), and protein modification either to simply enhance permeability or to exploit specific transporters. While proof-of-concept has been demonstrated with most of these delivery systems in animal... 

TMC is supposed to possess the property of permeation enhancement, and therefore has been studied as a delivery vector for proteins and genes. For example, TMC nanoparticles were prepared by ionic crosslinking with tripolyphosphate (TPP) and used as a delivery system for ovalbumin [30]. The loading efficiency and capacity of the protein were up to 95% and 50%, respectively, with an improved integrity. Most importantly, transportation of the protein-loaded particles across nasal mucosa was confirmed by an in vivo uptake test. In another study, the influence of DQ on the property of protein-loaded TMC/TPP nanoparticles was investigated [31]. A lower DQ leads to an increased particle size and a slower release rate of protein. 

Research on oral liposomal delivery systems has moved forward with the development of polymer-modified liposomes. For example, targeted PEGylated liposomes furnished with folic acid for oral delivery were promising, showing enhanced permeability of dextran (used as a marker) across Caco-2 cell monolayers (Anderson et al., 1999). PEG and chitosan-coated lipid nanoparticles were constmcted as oral delivery systems for salmon calcitonin (sCT). The PEG-coated nanoparticles did not alter the transepithelial electrical resistance of Caco-2 cell monolayers, while the chitosan-coated nanoparticles showed a dose-dependent increase in the permeability of dextran across the monolayers (Garcia-Fuentes et al., 2005). It demonstrated that the favourable interaction of the chitosan-coated nanoparticles with intestinal mucosa, together with their permeation enhancing characteristics, could improve the oral absorption of sCT. 

Mazzaferro S, Bouchemal K, Skanji R, Gueutin C, Chacun H, Ponchel G. Intestinal permeation enhancement of docetaxel encapsulated into methyl-p-cyclodextrin/ poly(isobutylcyanoacrylate)nanoparticles coated with thiolated chitosan. J Control Release. 2012 162(3) 568-74. 

Moghaddam FA, Atyabi F, Dinarvand R. Preparation and in vitro evaluation of mucoadhe-sion and permeation enhancement of thiolated chitosan-pHEMA core-sheU nanoparticles. Nanomed Nanotech Biol Med. 2009 5(2) 208-15. 

Chitosan has been investigated as a coating agent for novel formulations such as liposomes and solid lipid nanoparticles. The coating of chitosan on nanostructured systems increases the drug bioavailability owing to its permeation enhancement properties [166,167]. 

Cyclodextrins Natural Solubihty And Bioavailability Enhancer, Drug Stabihzation, Microparticles, Peptide Dehvery, Permeation Enhancer, Nanoparticles and Nanocapsule Sulindac, Paclitaxel Hydrocortisone... 

By utilizing polymerization in the miniemulsion system, larger HPG analogues can be created by linking several HPG units to a nanoparticle in order to obtain an optimum diameter of 50 nm [116], This size range is considered to be ideal for drug delivery carriers that may accumulate in tumors or inflamed tissue by the enhanced permeation and retention effect (EPR) [52],... 

Since the concentrations of insulin to be administered in the sheep model would have been large, the insulin-loaded chitosan nanoparticles were not investigated in that model. However, the pharmacodynamics and pharmacokinetics of various insulin-chitosan preparations were compared with postloaded insulin-chitosan nanoparticles. It was found that chitosan solution and chitosan powder formulations were far better, with the chitosan powder formulation showing a bioavailability of 17% as against 1.3 and 3.6% for the chitosan nanoparticles and chitosan solution [72], The effects of the concentration and osmolarity of chitosan and the presence of absorption enhancers in the chitosan solution on the permeation of insulin across the rabbit nasal mucosa in vitro and in vivo were investigated, and the same... 

This is unfortunate because the theoretical advantage of nanosystems is their small size, allowing freer movement than microspheres in the circulation, including the lymph and in tissues. Flow rates are important not least in the determination of the possibility of nanoparticle interaction with endothelial receptors prior to internalization, or indeed in the decoupling of carriers and receptors due to shear forces. Flow of nanoparticles is a vital element in extravasation and in the enhanced permeation and retention (EPR) effect. What is the influence of nanoparticle size on particle flow in the circulation And, with the advent of CNTs in particular, what is the influence of shape on flow and fate CNTs certainly behave differently in the blood from spherical C60 fidlerenes. CNTs activate human platelets and induce them to aggregate, whereas their spherical analogues do not... 

A modified melt blending method has been developed for preparing exfoliated nanocomposites of poly(m-xylylene adipamide) with sodium montmoril-lonite [100]. There, an aqueous solution of sodium montmorillonite was blended with the polymer in a twin-screw extruder. This kind of mixing ensures that the silica nanoparticles are exfoliated in the polymer matrix through fixing the nanoparticles within the polymer matrix just as they are in water. Oxygen permeation data show enhanced the barrier properties of the nanocomposites. 

---