Mesoporous carriers have been extensively applied to improve the dissolution velocity and bioavailability of insoluble drugs. The goal of this work was to compare the drug-loading efficiency (LE) and drug-dissolution properties of mesoporous silica nanoparticles (MSN) and mesoporous carbon nanoparticles (MCN) as drug vectors oral delivery of water-insoluble drugs. For this purpose, MSN and MCN with similar particle size, surface area, and mesoporous diameter were prepared to precisely evaluate the effects of different textures on the drug-loading and dissolution behavior of insoluble drugs. Carvedilol (CAR), a Bio-pharmaceutic Classification System (BCS) class II drug, was loaded in the MSN and MCN by the solvent adsorption method and solvent evaporation method with different carrier–drug ratios. The carboxylated MCN (MCN–COOH) had a higher LE for CAR than MSN for both the two loading methods due to the strong adsorption effect and π–π stacking force with CAR. In vitro drug dissolution study showed that both MSN and MCN-COOH could improve the dissolution rate of CAR compared with the micronized CAR. In comparison to MSN, MCN-COOH displayed a slightly slower dissolution profile, which may be ascribed to the strong interaction between MCN-COOH and CAR. Observation of cell cytotoxicity and gastrointestinal mucosa irritation demonstrated the good biocompatibility of both MSN and MCN–COOH. The present study encourages further research of different carriers to determine their potential application in oral administration.

Currently, the obvious side effects of anti-tumor drugs, premature drug release, and low tumor penetration of nanoparticles have largely reduced the therapeutic effects of chemotherapy. A drug delivery vehicle (MCN-SS-GQDs) was designed innovatively. For this, the mesoporous carbon nanoparticles (MCN) with the capabilities of superior photothermal conversion efficiency and high loading efficiency were used as the skeleton structure, and graphene quantum dots (GQDs) were gated on the mesopores via disulfide bonds. The doxorubicin (DOX) was used to evaluate the pH-, GSH-, and NIR-responsive release performances of DOX/MCN-SS-GQDs. The disulfide bonds of MCN-SS-GQDs can be ruptured under high glutathione concentration in the tumor microenvironment, inducing the responsive release of DOX and the detachment of GQDs. The local temperature of a tumor increases significantly through the photothermal conversion of double carbon materials (MCN and GQDs) under near-infrared light irradiation. Local hyperthermia can promote tumor cell apoptosis, accelerate the release of drugs, and increase the sensitivity of tumor cells to chemotherapy, thus increasing treatment effect. At the same time, the detached GQDs can take advantage of their extremely small size (5–10 nm) to penetrate deeply into tumor tissues, solving the problem of low permeability of traditional nanoparticles. By utilizing the photothermal properties of GQDs, synergistic photothermal conversion between GQDs and MCN was realized for the purpose of synergistic photothermal treatment of superficial and deep tumor tissues.