Cationic Polymer Nanoparticles and Nanogels: From Synthesis to Biotechnological Applications

Cationic polymer particles and nanogels are being used in emerging biomedical technologies due to the strong interaction between nucleic acids and cationic polymer colloids, the acid-swellable behavior of the nanoparticle/nanogel, and the ability to form oriented bonds with proteins, among other aspects. One of the most challenging applications is the use of cationic nanogels as carriers or vectors for in vivo siRNA delivery. The use of RNA interference to treat or prevent a variety of diseases, is a challenge in the biomedical field of therapeutics. New nanogel architectures or nanostructures should be envisaged for the adequate and controlled cell-specific siRNA release. Adequate nanogel sizes and shells are required for Improved stealth properties for the nanogels, avoiding recognition by the immune system (phagocytes), and enhancement of tumor accumulation, taking advantage of the EPR (enhanced permeability and retention) effect in tumors. The design of new nanogels sensitive to or able to respond to other in vivo stimuli different from the pH, temperature, or ionic strength is needed.