Intranasal Nose-to-Brain Drug Delivery via the Olfactory Region in Mice: Two In-Depth Protocols for Region-Specific Intranasal Application of Antibodies and for Expression Analysis of Fc Receptors via In Situ Hybridization in the Nasal Mucosa.

A region-specific catheter-based intranasal administration method was successfully developed, established, and validated as reported previously. By using this method, drugs can be applicated specifically to the olfactory region. Thereby, intranasally administered drugs could be delivered via neuronal connections to the central nervous system. Here, we present a detailed protocol with a step-by-step procedure for nose-to-brain delivery via the olfactory mucosa.Fc receptors such as the neonatal Fc receptor (FcRn) and potentially Fcγ receptor IIb (FcγRIIb) are involved in the uptake and transport of antibodies via the olfactory nasal mucosa. To better characterize their expression levels and their role in CNS drug delivery via the nose, an in situ hybridization (ISH) protocol was adapted for nasal mucosa samples and described in abundant details.

Impact of Glycosylation and Species Origin on the Uptake and Permeation of IgGs through the Nasal Airway Mucosa.

Although we have recently reported the involvement of neonatal Fc receptor (FcRn) in intranasal transport, the transport mechanisms are far from being elucidated. Ex vivo porcine olfactory tissue, primary cells from porcine olfactory epithelium (OEPC) and the human cell line RPMI 2650 were used to evaluate the permeation of porcine and human IgG antibodies through the nasal mucosa. IgGs were used in their wild type and deglycosylated form to investigate the impact of glycosylation. Further, the expression of FcRn and Fc-gamma receptor (FCGR) and their interaction with IgG were analyzed. Comparable permeation rates for human and porcine IgG were observed in OEPC, which display the highest expression of FcRn. Only traces of porcine IgGs could be recovered at the basolateral compartment in ex vivo olfactory tissue, while human IgGs reached far higher levels. Deglycosylated human IgG showed significantly higher permeation in comparison to the wild type in RPMI 2650 and OEPC, but insignificantly elevated in the ex vivo model. An immunoprecipitation with porcine primary cells and tissue identified FCGR2 as a potential interaction partner in the nasal mucosa. Glycosylation sensitive receptors appear to be involved in the uptake, transport, but also degradation of therapeutic IgGs in the airway epithelial layer.