Functionalization of polysulfide nanoparticles and their performance as circulating carriers.

We here present an evaluation of the carrier performance of nanoparticles that are biofunctional, i.e. derivatized to provide a controlled biological activity, and environmentally responsive, since they respond to the presence of oxidants.

In vivo targeting of dendritic cells in lymph nodes with poly(propylene sulfide) nanoparticles.

Delivery of biodegradable nanoparticles to antigen-presenting cells (APCs), specifically dendritic cells (DCs), has potential for immunotherapy. This study investigates the delivery of 20, 45, and 100nm diameter poly(ethylene glycol)-stabilized poly(propylene sulfide) (PPS) nanoparticles to DCs in the lymph nodes. These nanoparticles consist of a cross-linked rubbery core of PPS surrounded by a hydrophilic corona of poly(ethylene glycol).

Oxidation-sensitive polymeric nanoparticles.

We have recently demonstrated the possible use of organic polysulfides for the design of oxidation-sensitive colloidal carriers in the form of polymeric vesicles, which are particularly suitable for the encapsulation of hydrosoluble drugs. In the present research we extend our efforts to carriers specifically suitable for hydrophobic molecules. Exploiting the living emulsion polymerization of episulfides, we have produced new cross-linked polysulfide nanoparticles.

Intra-portal injection of 400- microm microcapsules in a large-animal model.

To date, encapsulated grafts have usually been implanted in the peritoneal cavity. This site is, however, not ideal, mainly because of its low blood supply. We have investigated the feasibility of intra-portal injection of (400 microm) microcapsules in the pig.

Improving cell encapsulation through size control.

Capsules based on the polyelectrolyte complexation between the polyanions sodium alginate and sodium cellulose sulphate with the polycation poly(methylene-co-guanidine) hydrochloride in the presence of calcium chloride have previously shown important advantages for cell encapsulation. However, in vivo long-term applications require capsule features that are well suited for the functionality of encapsulated cells. These should be targeted to the site of implantation with an appropriate size, a relative stability, and suitable diffusion properties.