Annular Mesoporous Carbonaceous Nanospheres from Biomass-Derived Building Units with Enhanced Biological Interactions

Here, hydrothermal biomass-derived nanospheres were designed to enhance cellular delivery in biomedicine and to overcome the difficulties in the synthesis of small mesoporous hydrothermal carbonaceous nanospheres (SMHNs) below 100 nm in size. A facile kinetics-controlled soft-template strategy was developed to construct annular SMHN with precisely tunable sizes of 30-80 nm, ordered channels, and abundant functional glycosylation groups using monosaccharides as the carbon source. SMHN exhibited a high loading capacity of 503 mg g^-1 for doxorubicin due to the mesoporous structure and rich functional glycosylation groups. Moreover, SMHN displayed low cytotoxicity and few hemolytic effects and biological interactions, showing efficient internalization performance. Cells treated with fluorescein isothiocyanate-loaded SMHN had high mean fluorescence intensity within 75 min, which is significantly higher than that of the carbon counterparts. It is believed that the biological interactions of SMHNs are attributed to the reserved functional glycosylation groups that can activate glucose transporters and mediate endocytosis across the cytomembrane. The approach used to construct SMHN provides great opportunities for the generation of small mesoporous carbonaceous particles with rough annular structures. Moreover, the bottom-up construction strategy provides new understanding of the rational design and synthesis of biomass-derived vectors for efficient drug delivery.