Disclosure of methods and compositions related to chemical conjugations to nanoparticles of polysaccharides cross-linked to poloxamers as well as nano-sized colloids comprised of polysaccharides and poloxamers. The nanoparticles may be produced by various methods including inverse miniemulsion polymerization processes which create nanogels of desired size, shape, and stability for controlled therapeutic drug delivery, imaging, and theragnostic applications.