Hybrids of Polysaccharides and Inorganic Nanoparticles: From Morphological Design to Diverse Biomedical Applications

ConspectusAs widespread natural polymers with biocompatibility, biodegradability, and bioactivity properties, polysaccharides are considered ideal candidates to fabricate multifunctional platforms for diverse biomedical applications. Inorganic nanoparticles have attracted increased attention due to their favorable physicochemical properties, while further modification is required to realize stability and biocompatibility. Therefore, the fabrication of hybrids of polysaccharides and inorganic nanoparticles into the nanoscale are desirable to facilitate the accumulation of nanohybrids through enhanced permeability and retention effect, which can not only realize complementary functions of individual components, but also produce new and synergistic properties.In addition, the morphology of biomaterials significantly influences their interaction with biological systems while it has been proved that the morphological design of nanoparticles leads to the enhancement of related properties and performances. In this regard, hybrids of polysaccharides and inorganic nanoparticles with superior morphologies can be investigated to enhance their performances. Several methods including surface modification, wrapping, and template strategies have been developed for the construction of versatile polysaccharide–inorganic nanohybrids with various morphologies. In particular, new and synergistic properties through morphological design can be produced. For example, the integration of dextran and Fe3O4 nanoparticles into one-dimensional nanohybrids can generate mechanical force under alternating magnetic field for magnetolytic therapy. Furthermore, other hybrid systems consisting of polysaccharides and inorganic nanoparticles, including hydrogels, electrospun scaffolds, and microneedles, enable local accumulation and retention of inorganic nanoparticles, which may help improve treatment outcomes and avoid potential systemic side effects. Based on these advantages, the properties, functions, and biomedical applications of polysaccharide–inorganic hybrids have been extensively explored.In this Account, we highlight recent developments on hybrids of polysaccharides and inorganic nanoparticles (nanohybrids and other hybrid systems) for biomedical applications. First, we summarize the efforts on the design and construction of nanohybrids by surface modification of inorganic nanoparticles, whose morphology was basically determined by inorganic cores. Then we present the attempts to construct nanohybrids with different morphologies through wrapping and template strategies, whose morphologies are determined by both polysaccharides and inorganic nanoparticles. The morphology effect of nanohybrids on their biological functions and performances is discussed. Based on the morphology-dependent findings, nanohybrids with advantageous morphologies including one-dimensional, star-shaped, Janus, and rough nanohybrids can be rationally designed, which demonstrate fascinating properties for efficient cancer therapy. We further summarize representative examples of versatile hybrid systems of polysaccharides and inorganic nanoparticles and their biomedical applications. Last, we provide a prospect on the challenges and opportunities of hybrids composed of polysaccharides and inorganic nanoparticles. We hope that this Account will provide clues to the rational design of promising hybrids of polysaccharides and inorganic nanoparticles and inspire more studies into morphology-dependent developments in the biomedical field.