The effect of a PEG versus a chitosan coating on the interaction of drug colloidal carriers with the ocular mucosa

Role of hydroxypropyl-β-cyclodextrin on freeze-dried and gamma-irradiated PLGA and PLGA–PEG diblock copolymer nanospheres for ophthalmic flurbiprofen delivery

“…53 However, the ex vivo study was performed in the absence of enzymes and mucin and, consequently, the expected positive effect of PEG coating was not evident. 54 Results obtained in vivo by other authors demonstrated the increase in ocular bioavailability by PEG coating of these colloidal systems. 8 Results showed that there was a significant decrease in P app when HPβCD was added to the formulations.…”

Bioadhesive hyaluronan–chitosan nanoparticles can transport genes across the ocular mucosa and transfect ocular tissue

“…Namely, (1) they are able to associate great amounts of DNA, thus allowing the amount of polymer used for in vivo transfection purposes to be minimized, (2) they have a very small size, a feature which is known to be critical for the adequate interaction with the ocular mucosa 28 and (3) their surface charge can be modulated depending on the HA-CS ratio. This modulation is important since a positive charge is supposed to facilitate the interaction of the nanoparticles with the ocular surface, 23,29 whereas the disposition of HA onto the surface of the nanoparticles may also play a role in their interaction with epithelial cells. 20,21 In order to evaluate the efficacy of the nanoparticles as ocular gene carriers, a cell culture model derived from HCE cells was used prior to the in vivo studies.…”

“…22 For example, we have previously found that CS-based nanoparticles remain associated to the ocular mucosa for extended periods of time and provide high concentrations of the encapsulated drug on the target site with minimal systemic exposure. 15,23 Overall, this information has led us to the assumption that nanoparticles made of the polysaccharides HA and CS could be of interest for the topical administration of genes onto the eye surface. Consequently, the main goal of the present work was to evaluate the potential of these nanoparticles as gene carriers for the treatment of ocular diseases.…”

Theory, fabrication and applications of microfluidic and nanofluidic biosensors

“…As an example, the use of monolayers to generate desired surface states for biosensing is discussed below. Surface modification has been essential for biosensors to immobilize affinity tags for binding of target molecules to surfaces [133][134][135][136][137][138]. For example, several platforms for cell, protein and DNA assays have been investigated [74,[139][140][141][142][143][144].…”