Preparation And Properties Of Nano-composites Based On Black Phosphorus

Black Phosphorus?BP?is a new type of two-dimensional material that has drawn great attention in the world.As the most stable allotrope compared to other phosphorus elements,BP has many unique properties.Different thicknesses of BP nanosheets?BPNSs?can be produced from bulk BP by stripping techniques.Unlike other two-dimensional materials such as graphene?zero bandgap semiconductors?,BP exhibits a layer-dependent band gap ranging from 0.3 eV?volume value?to?2.0 eV?single layer value?and performs high and wide absorption in the ultraviolet and near-infrared regions.In addition,BP is a promising photothermotherapy?PTT?nanomaterial due to the high extinction coefficient of near-infrared spectroscopy and photothermal conversion efficiency.The final degradation products of BP are phosphates and phosphonates,both of which are non-toxic.Therefore,BPNSs with good biocompatibility and excellent photothermal properties are suitable for biomedical applications.What's more,BPNSs have a higher specific surface area for more durgs than other two-dimensional materials such as graphene and MoS₂.Recently,some studies have shown that BPNSs have potential in drug delivery platforms.By loading anticancer drugs onto the surface of BP tablets,a versatile drug delivery system was proposed for synergistic photothermal/chemotherapy cancer.In this paper,we successfully synthesized and characterized two kinds of nano-composites based on black phosphorus which combine photothermal therapy and chemotherapy.The studies in vitro and in vivo experimental were carried out to test their biological properties.The research content is as follows:1.First,before the self-polymerization of DA to form a polydopamine?PDA?coating,BPNSs has already adsorbed anticancer drug doxorubicin?DOX?by electrostatic interaction.The nanocomposites were characterized using scanning electron microscopy?SEM?,high-resolution transmission electron microscopy?HR-TEM?,ultraviolet-visible spectrophotometer?UV-vis?,and Fourier transform infrared spectrometer?FT-IR?,which prove the successful preparation of BPNSs-DOX@PDA,and also,BPNSs-DOX@PDA exhibits a lot advantages,including extremely excellent water solubility and stability,high drug loading capacity,enhanced photothermal performance and low toxicity.Moreover,drug release can be accelerated under acidic conditions and laser irradiation.We find that our nanocomposite BPNSs-DOX@PDA provides a good platform for future cancer treatment.2.We successfully prepared a novel BPNSs/PNIPAM-g-CS nanogel based on PNIPAM-g-CS,and loaded DOX and CUR into BPNSs/PNIPAM-g-CS to overcome drug resistance and enhance the therapeutic efficacy in vitro and in vivo.We find that BPNSs/PNIPAM-g-CS nanogel exhibits extraordinary swelling/deswelling behavior,and the particle size can vary with different temperature and pH value.The BPNSs in the nanogel act as the core to not only enhance the stability of the composite nanogel,but also act as PTT agents to exert hyperthermia induced by NIR irradiation.The composite nanogel also has pH and light-response release,DOX release can be accelerated when BPNSs/PNIPAM-g-CS/DOX is exposed to slightly acidic environment or NIR irradiation.In addition to that,as-prepared nanocomposite BPNSs/PNIPAM-g-CS has excellent biocompatibility,hemodynamic stability and ability to keep drug from brust release after drug loading.The co-delivery system show great anticancer effect in vitro and in vivo and has tremendous potential for clinical application in cancer chemotherapy.