• Von, Eva Haartman
• Burikov, Sergey A.
• Zhang, Jixi
• Jiang, Hua
• Khomich, Andrei A.
• Shenderova, Olga A.
• Vlasov, Igor I.
• Rosenholm, Jessica M.
• Dolenko, Tatiana A.
• Ruokolainen, Janne
• Hongchen, Gu

Abstract

A multifunctional core–shell nanocomposite platform consisting of aphotoluminescent nanodiamond (ND) core with uniform porous silicacoatings is presented. This design intended for drug deliveryapplications allows simultaneous stable fluorescent imaging with highloading capacity of bioactive molecules. Despite irregularly shapedstarting cores, well-dispersed and uniformly shaped nanocompositeparticles can be produced. Moreover, after optimization of the silicasource-to-diamond ratio, the thickness of the porous layer can be tunedby adjusting the ethanol amount, allowing rational nanoparticle sizecontrol. The ND key property, photoluminescence, is not quenchedregardless of coating with thick silica layers. The high loadingcapacity for incorporation of active agents, provided by the introducedporous layer, is demonstrated by adsorption of a hydrophobic model drugto the composite particles. The loading degree, as compared to a pureND, increased by two orders of magnitude from 1 wt% for the ND to>100 wt% for the composite particles. Combining these two materialclasses, which both have well-documented excellent performanceespecially in biomedical applications, for the NDs with emphasis, butnot exclusively, on imaging and mesoporous silica (MSN) on drugdelivery, the advantages of both are shown here to be synergisticallyintegrated into one multifunctional nanocomposite platform.

Topics

• nanoparticle
• porous
• nanocomposite
• impedance spectroscopy
• photoluminescence