Mucosal Vaccine Delivery and M Cell Targeting

Encapsulation of Antifouling Organic Biocides in Poly(lactic acid) Nanoparticles

“…Following nanoparticles preparation, both loaded and blank PLA NPs showed negligible crystallinity compared to the polymer matrix and exhibited a behavior of an amorphous material ( Figure 8 , Figure 9 and Figure 10 ). Such a low degree of crystallinity corresponds theoretically to increased biocide release and fast degradation of the carrier [ 62 , 63 ]. The low crystallinity in the carrier implies firstly higher amounts of amorphous regions, and thus easier diffusion of the active through the matrix amorphous phase.…”

Carbohydrate Immune Adjuvants in Subunit Vaccines

“…The mucosal immune system consists of an integrated network of tissues, lymphoid and constitutive cells, and effector molecules (antibodies, cytokines, and chemokines) [ 29 ]. As such, mucosal infection, or a mucosal-administered vaccine, can result in the activation of protective B- and T-cells in both mucosal and systemic environments [ 30 ].…”

“…In addition, these sites comprise a complex network of innate and adaptive immune components, such as DCs, macrophages, T-cells, B-cells, and natural killer (NK) cells, which are overlayered with epithelial cells and specialized microfold cells (M-cells) [ 33 ]. M-cells offer functional openings in the epithelial barrier through vesicular transport activity, and the ability of antigens to release the intraepithelial space, facilitating antigen contact with T and B lymphocytes and macrophages [ 30 , 34 ]. Besides M-cells, the antigen can be collected by the receptors present on DC transepithelial dendrites (active transport).…”

“…Targeting the mucosal routes (e.g., oral, nasal, pulmonary, ocular, rectal, vaginal, etc.) has several advantages over parenteral vaccination, including: (a) injection can be avoided, reducing the risk of needle-stick injury and cross-contamination [ 35 ]; (b) full sterilization of the vaccine is not required; (c) the vaccine can be self-delivered; (d) vaccine storage conditions are usually less restrictive [ 36 ]; (e) immunization of one mucosal site often induces immune responses in other mucosal effector tissues [ 37 ]; and (f) most importantly, the production of mucosal antibodies (IgA) can prevent systemic infection [ 30 , 38 ].…”

“…Nanoparticles based on polysaccharides can interact with M-cells and undergo endocytosis and transcytosis [ 39 , 40 ]. Carbohydrates, for example, chitosan-based carriers, can open tight junctions to directly transfer antigens through epithelial barriers [ 30 ]. These carriers also provide a prolonged interaction between associated antigens and epithelial cells due to chitosan’s mucoadhesive properties.…”