Gold Nanorods Conjugated Porous Silicon Nanoparticles Encapsulated in Calcium Alginate Nano Hydrogels Using Microemulsion Templates

Porous silicon nanoparticles (PSiNPs) and gold nanorods (AuNRs) can be used as biocompatible nanocarriers for delivery of therapeutics but undesired leakage makes them inefficient. By encapsulating the PSiNPs and AuNRs in a hydrogel shell, we create a biocompatible functional nano carrier that enables sustained release of therapeutics. Here, we report the fabrication of AuNRs-conjugated PSi nanoparticles (AuNRsPSiNPs) through two-step chemical reaction for high capacity loading of hydrophobic and hydrophilic therapeutics with photothermal property. Furthermore, using water-in-oil microemulsion templates, we encapsulate the AuNRsPSiNPs within a calcium alginate hydrogel nanoshell, creating a versatile biocompatible nanocarrier to codeliver therapeutics for biomedical applications. We find that the functionalized nanohydrogel effectively controls the release rate of the therapeutics while maintaining a high loading efficiency and tunable loading ratios. Notably, combinations of therapeutics coloaded in the functionalized nanohydrogels significantly enhance inhibition of multidrug resistance through synergism and promote faster cancer cell death when combined with photothermal therapy. Moreover, the AuNRs can mediate the conversion of near-infrared laser radiation into heat, increasing the release of therapeutics as well as thermally inducing cell damage to promote faster cancer cell death. Our AuNRsPSiNPs functionalized calcium alginate nanohydrogel holds great promise for photothermal combination therapy and other advanced biomedical applications.