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Waste toner with high carbon content has the potential to become a carbon material, but its utilization is limited due to the low carbonization yield. In this work, a carbon-based solid acid was prepared by carbonization and sulfonation of waste toner with the aid of sulfuric acid. The characterization of its structure and the evaluation of its properties revealed that sulfuric acid played three roles in the process of carbon-based solid acid prepared from waste toner (WT-CSA). Specifically, this method not only solved the problem of low yield of carbon precursor (CP) obtained by carbonization of waste toner but also introduced thiophene sulfur into the aromatic carbon flakes during the carbonization process. Moreover, thiophene sulfur makes the sulfonation easier, thus increasing the density of –SO3H. In addition, the activity and cyclic stability of the catalyst were evaluated by cellulose hydrolysis. The results show that the catalyst exhibits excellent hydrolytic activity and hydrothermal stability. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma is one of the most common malignant tumours in the oral and maxillofacial regions and is highly malignant and prone to recur despite the development of various effective treatments, including surgery and chemoradiotherapy. Actually, it is difficult to ensure the complete elimination of tumour cells, and maxillofacial bone defects caused by surgery are hard to heal by themselves. In addition, chemoradiotherapy can bring serious side-effects. Therefore, it is imperative to develop a postoperative therapy to kill residual squamous cancer cells and repair bone defects without any side-effects. Here, we prepared a 3D scaffold by a 3D printing technique and freeze-drying method, which contained collagen, silk and hydroxyapatite (CSH) and was functionalized with MXene nanosheets (M-CSH). The considerable photothermal effect with long-term stability can significantly kill squamous CAL-27 cancer cells in vitro and inhibit tumour growth in vivo , increasing the probability of the M-CSH scaffold being applied in the photothermal therapy of oral squamous cell carcinoma. Moreover, the cell proliferation- and osteogenic-related protein expression of mouse embryonic osteogenic precursors (MC3T3-E1) indicated excellent biocompatibility and osteogenic activity of M-CSH scaffolds. The good compression modulus (52.83 ± 2.25 kPa) and in vivo bone formation performance made it possible to be used as reconstructive materials for bone defects. This scaffold is likely promising in future tissue engineering, especially for the multifunctional treatment of maxillofacial tumours. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to develop a novel formulation of oleanolic acid (OA) solid dispersion (SD), using leucine (Leu) as the carrier to improve OA oral bioavailability. Methods: The OA‐Leu SD was prepared by solvent evaporation and was evaluated in vitro using differential scanning calorimetry, X‐ray powder diffraction, scanning electron microscopy, flowability, hygroscopicity and dissolution test. The stability of the SD was evaluated using accelerated testing. In vivo pharmacokinetic tests were performed in male Sprague Dawley rats using a liquid chromatography tandem‐mass spectrometry bioanalytical method. Key findings: OA‐Leu SD was successfully prepared, and OA was mostly in an amorphous state. More than 80% of OA could dissolve in OA‐Leu SD in 20 min, while only 13.4% of free OA dissolved. The powder flow of OA‐Leu SD was clearly improved compared with free OA and its moisture absorption was 3.4%. The accelerated testing further demonstrated that SD could maintain OA in an amorphous state at 40 °C for 6 months. OA‐Leu SD showed higher relative oral bioavailability (189.7%) than free OA in rats. Conclusions: Using Leu as a carrier produced a SD with good flowability, low hygroscopicity and high bioavailability. [ABSTRACT FROM AUTHOR]