eventually pre-swollen, to facilitate the NP diffusion through the outer mesh and their loading into the macropores. The reduction or oxidation of metal salts (e.g., AgNO3, HAuCl4, CuCl2) blended with the polymer solution is a simple method for in situ NP synthesis. Similarly, the homogeneous formation of CaP NPs within a gel matrix was achieved by Ca 2+ nucleation in presence of poly(L-glutamic acid) (PGA) and PO4 3-. The mixing can be achieved by a variety of methods ranging from simple pipetting, magnetic stirring, vortexing and/or sonication over different durations (from a minimum of 10 s up to 24 h). To ensure thorough mixing, standard practice is the use of syringes and luer-lock elbow connectors or doublebarrel syringes also fitted with a static mixer, so that reagents are opportunely mixed during injection (Figure ). Copyright 2013 American Chemical Society. (c) Fabrication process of a hybrid hydrogel made of PNIPAAm-hydrazide-coated super paramagnetic iron oxide NPs (SPIONs) and Dex-CHO using a double barrel syringe with static mixer. Adapted with permission. Copyright 2013 American Chemical Society.