Nanogels are nanosized polymer networks swollen in a liquid, i.e. water. Nanogels that respond to certain pH changes by changing its volume have gain great importance due to the fact that tumor tissues are known to show slightly acidic pH compared to healthy tissues. Therefore pH sensitive nanogels are good candidates for biomedical applications, for example, for pH triggered drug delivery. In this contribution a synthetic approach has been established for the preparation of nanogels formed by a pH responsive core of poly(N,N’-diethylaminoethyl methacrylate) (PDEAEM) and a shell of the biocompatible polymer polyethylene glycol (PEG). The methodology used for the synthesis was the “soap-less” emulsion polymerization, i.e. an emulsion polymerization reaction without surfactant, where a methacrylate functionalized PEG (PEGMA) acts as stabilizer for the monomer droplets while it was incorporated by free radical reaction as shell over the crosslinked PDEAEM nano-particle. For stabilizing the polymeric nanoparticles and providing them with a network structure, three different crosslinkers were tested: ethylene glycol dimethacrylate (EGDMA), N,N -bis(acryloyl)cystamine (BAC), and a divinylacetal compound (DVA), furthermore the effect of the type of water soluble initiator, an azo compound (AIBA) and two persulphate initiators (APS and KPS) has been studied. Dynamic light scattering results show that the average diameter of the nanogels decreased from 274 nm down to 73 nm with increasing PEGMA content in the recipe, while maintaining a narrow size distribution. It has been observed under similar synthetic conditions that the crosslinker type and initiator affects the average diameter and the size distribution. Furthermore, with the aim to develop dual therapy nanogels, gold nanoparticles were prepared in situ and also ex-situ and incorporated in addition to 5-Fluorouracil, into selected nanogels and tested in drug delivery experiments.

Pegylated cationic nanogels based on PDEAEM for drug delivery

251st National Meeting (2016)

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