As a biodegradable material, black phosphorus (BP) has been considered as an efficient agent for cancer photothermal therapy. However, its systemic delivery faces several hurdles, including rapid degradation in blood circulation, quick clearance by the immune system, and low delivery sufficiency to the tumor site. Here, we developed a biomimetic nanoparticle platform for in vivo tumor-targeted delivery of BP nanosheets (BP NSs). Through a biomimetic strategy, BP NSs were utilized to coordinate with the active species of oxaliplatin (1,2-diaminocyclohexane) platinum (II) (DACHPt) complexions, and the nanoparticles were further camouflaged with mesenchymal stem cell (MSC)–derived membranes. We showed that the incorporation of DACHPt not only decelerated the BP degradation but also enhanced the antitumor effect by combining the photothermal effect with chemotoxicity. Furthermore, MSC membrane coating increased the stability, dispersibility, and tumor-targeting properties of BP/DACHPt, significantly improving the antitumor efficacy. In short, our work not only provided a new strategy for in vivo tumor-targeted delivery of BP NSs but also obtained an enhanced antitumor effect by combining photothermal therapy with chemotherapy.

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Transplanting stem cells with the abilities of self-renewal and differentiation is one of the most effective ways to treat many diseases. In order to optimize the therapeutic effect of stem cell transplantation, it is necessary to intervene in stem cell differentiation. Inorganic nanomaterials (NMs), due to their unique physical and chemical properties, can affect the adhesion, migration, proliferation and differentiation of stem cells. In addition, inorganic NMs have huge specific surface area and modifiability that can be used as vectors to transport plasmids, proteins or small molecules to further interfere with the fate of stem cells. In this mini review, we summarized the recent advances of common inorganic NMs in regulating stem cells differentiation, and the effects of the stiffness, size and shape of inorganic NMs on stem cell behavior were discussed. In addition, we further analyzed the existing obstacles and corresponding perspectives of the application of inorganic NMs in the field of stem cells.

Background: Wound healing of skin is a complicated process. Cutaneous innervation and neurotrophic factors could participate in multiple stages of wound healing. Neurotrophic factors are mainly produced and released by neurons and neural stem cells (NSCs) which could be obtained in large quantities from human-induced pluripotent stem cells (iPSCs) in vitro. However, the potential wound healing effects of NSC secretions, such as exosomes, are unexplored yet. Methods: NSCs-derived exosomes (NSC-exo) and iPSCs-derived exosomes (iPSC-exo) were isolated from the cell culture supernatants by centrifugation, and then quantified and characterized. The effects of these exosomes on the migration of human dermal fibroblasts (HDF) cells and the tube formation of human umbilical vein endothelial cells (HUVECs) were investigated in vitro. And the in vivo wound healing effect of these exosomes were tested on the mouse skin trauma model. Therefore, a dipeptide/hyaluronic acid (Nap-FF/HA) composite hydrogel was used to encapsulate the exosomes as a sustained release carrier. Histological observations were performed to evaluate the wound healing effect of exosomes. Furthermore, the non-labeling proteomic analysis was performed to explore the possible mechanisms of NSC-exo on wound healing. Results: We obtained extracellular vesicles in a bowl-like structure with membranes which meet the general standards of exosomes. NSC-exo showed promotion effect on the migration of HDF cells and the tube formation of HUVECs in vitro. In a mouse skin injury model, NSC-exo enhanced the wound healing and the Nap-FF/HA hydrogel that contained exosomes did so with less drug frequency by sustaining release of exosomes. Further proteomic analysis demonstrated that the carried neurotrophic factors and immunity-related proteins in NSC-exo may play a functional role in wound healing. Conclusion: NSC-exo may enhance wound healing via neurotrophic factors and immunomodulation.

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