Applications and perspectives of quaternized cellulose, chitin and chitosan: A review.

Recently, increasing attention has been paid to natural polysaccharides for their low cost, biocompatibility and biodegradability. Quaternization is a modification method to improve the solubility and antibacterial ability of natural polysaccharides. Water-soluble derivatives of cellulose, chitin and chitosan offer the prospect of diverse applications in a wide range of fields, such as antibacterial products, drug delivery, wound healing, sewage treatment and ion exchange membranes. By combining the inherent properties of cellulose, chitin and chitosan with the inherent properties of the quaternary ammonium groups, new products with multiple functions and properties can be obtained. In this review, we summarized the research progress in the applications of quaternized cellulose, chitin and chitosan in recent five years. Moreover, ubiquitous challenges and personal perspectives on the further development of this promising field are also discussed.

Tumor-triggered targeting ammonium bicarbonate liposomes for tumor multimodal therapy.

Tumor-triggered targeting ammonium bicarbonate (TTABC) liposomes were proposed to improve the uptake of ammonium bicarbonate (ABC) liposomes in tumor cells and retain their long circulation in vivo in our previous study. However, it must be solved how to precisely release the loaded drugs of the TTABC liposomes into tumor cells. In addition, synergistic multimodal therapy could result in better tumor treatment outcomes than monomodal chemotherapy. In the research, we prepared indocyanine green (ICG) and doxorubicin (DOX) encapsulated TTABC liposomes (ICG&DOX@TTABC) to achieve near-infrared (NIR) light-controlled chemo/photothermal/photodynamic multimodal therapy guided by fluorescence and photothermal imaging. In vitro and vivo studies show that ICG&DOX@TTABC can specifically accumulate in tumor tissues, effectively transform NIR light into local thermo-therapy, and have excellent anti-tumor ability without obvious side effects. ICG&DOX@TTABC could be promising for fluorescence and photothermal imaging-guided chemo/photothermal/photodynamic tumor treatment.

Preparation and in Vitro Antitumor Study of Two-Dimensional Muscovite Nanosheets.

Inorganic nanosheets are endowed with many two-dimensional (2D) morphological features including ultra-high specific surface area, ultra-thin thickness, easy functionalization, and so on. They push forward an immense influence on effective cancer diagnosis and therapy, overcoming the inherent limitations of traditional treatment methods. However, long-term toxicity and poor biocompatibility are the critical issues for most inorganic nanosheets, which hinder their further oncological applications and clinical translations. Muscovite, also named white mica (WM), an aluminosilicate, is a major component of traditional Chinese medicine, which can be exfoliated into 2D nanosheets and expected to be a potential drug carrier. In this study, WM powder was exfoliated to prepare WM nanosheets (WMNs) through a polyamine intercalation method. In addition, doxorubicin hydrochloride (Dox) was loaded to WMNs via physical adsorption and electrostatic interaction to prepare Dox-loaded WMNs (Dox@WMNs). Then, we studied that Dox@WMNs released Dox in phosphate buffer saline. We also studied the cellular uptake and cytotoxicity of Dox@WMNs in vitro. The results illustrated that Dox@WMNs cumulatively released Dox much faster and more at acidic pH (6.0 and 4.6) compared with that at physiological pH. In addition, WMNs showed selective cytotoxicity. Within a certain concentration range, WMNs were cytotoxic to Hela cells but non-cytotoxic to RAW 264.7 cells. Compared with cytotoxicity at pH 7.4, the cytotoxicity of Dox@WMNs was significantly enhanced at pH 6.4 and 4.6. WMNs mainly promoted the immunostimulatory polarization of RAW 264.7 cells into M1 macrophages.