The scientific and industrial need for novel composite materials and nanoparticles has opened new paths and led to significant advances in the field of nanocomposites. A number of nanosystems can be designed based on their unique physico-chemical structures for direct biomedical applications. This review is focused on the most novel strategies and trends to design metal nanoparticles including thermal decomposition, chemical reduction and green methods. These methods can be applied to fabricate polymer metal nanocomposites into different forms: core –shell, hollow core- shell nanoparticle system, metal nanoparticles in hydrogel matrix and layer by layer assembly systems. The resulting new class of materials found fascinating interest in antimicrobial, drug delivery and in catalysis.