Size-dependent osteogenesis of black phosphorus in nanocomposite hydrogel scaffolds.

A promising new strategy emerged in bone tissue engineering is to incorporate black phosphorus (BP) into polymer scaffolds, fabricating nanocomposite hydrogel platforms with biocompatibility, degradation controllability, and osteogenic capacity. BP quantum dot is a new concept and stands out recently among the BP family due to its tiny structure and a series of excellent characteristics. In this study, BP was processed into nanosheets of three different sizes via different exfoliation strategies and then incorporated into cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) to produce nanocomposite hydrogels for bone regeneration. The three different BP nanosheets were designated as BP-L, BP-M, and BP-S, with a corresponding diameter of 242.3 ± 90.0, 107.1 ± 47.9, and 18.8 ± 4.6 nm. The degradation kinetics and osteogenic capacity of MC3T3 pre-osteoblasts in vitro were both dependent on the BP size. BP exhibited a controllable degradation rate, which increased with the decrease of the size of the nanosheets, coupled with the release of phosphate in vitro. The osteogenic capacity of the hydrogels was promoted with the addition of all BP nanosheets, compared with OPF hydrogel alone. The smallest BP quantum dots was shown to be optimal in enhancing MC3T3 cell behaviors, including spreading, distribution, proliferation, and differentiation on the OPF hydrogels. These results reinforced that the supplementation of BP quantum dots into OPF nanocomposite hydrogel scaffolds could potentially find application in the restoration of bone defects.

Exosome CTLA-4 Regulates PTEN/CD44 Signal Pathway in Spleen Deficiency Internal Environment to Promote Invasion and Metastasis of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common primary cancers, and its pathogenesis is complicated and difficult to screen. Currently, there is no effective treatment. In traditional Chinese medicine, a large proportion of patients with HCC have been diagnosed with spleen deficiency (SD) syndrome and treated with tonifying traditional Chinese medicine, which has significant clinical efficacy. However, the role and molecular mechanism of SD in HCC remain unclear. In this study, 40 mice were randomly divided into four groups: control, SD, HCC, and SD-HCC groups. The liver cancer model of SD was established by reserpine induction and orthotopic transplantation. The effects of SD on the proliferation, apoptosis, invasion, and metastasis of HCC cells were studied by cell proliferation, cell apoptosis, cell scratch, and transwell assay. We found that compared with the HCC group, the protein expressions of cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), phosphatase and tensin homolog (PTEN), and AKT (also known as protein kinase B or PKB) in the exosomes of the SD-HCC group were upregulated. In addition, the metastases and self-renewal of exosomes in the SD-HCC group were more aggressive than those in the HCC group, which could be partially reversed with the addition of CTLA-4 inhibitors. Further studies showed that in the internal environment of SD, CTLA-4 promoted tumor invasion and metastasis by regulating the PTEN/CD44 pathway. In conclusion, our findings suggest that during SD in the internal environment, exosome CTLA-4 regulates the PTEN/CD44 signal pathway to promote the proliferation, self-renewal, and metastasis of liver cancer.

Black phosphorus incorporation modulates nanocomposite hydrogel properties and subsequent MC3T3 cell attachment, proliferation, and differentiation.

A promising strategy that emerged in tissue engineering is to incorporate two-dimensional (2D) materials into polymer scaffolds, producing materials with desirable mechanical properties and surface chemistries, which also display broad biocompatibility. Black phosphorus (BP) is a 2D material that has sparked recent scientific interest due to its unique structure and electrochemical characteristics. In this study, BP nanosheets (BPNSs) were incorporated into a cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) hydrogel to produce a new nanocomposite for bone regeneration. BPNSs exhibited a controllable degradation rate coupled with the release of phosphate in vitro. MTS assay results together with live/dead images confirmed that the introduction of BPNSs into OPF hydrogels enhanced MC3T3-E1 cell proliferation. Moreover, the morphology parameters indicated better attachments of cells in the BPNSs containing group. Immunofluorescence images as well as intercellular ALP and OCN activities showed that adding a certain amount of BPNSs to OPF hydrogel could greatly improve differentiation of pre-osteoblasts on the hydrogel. Additionally, embedding black phosphorous into a neutral polymer network helped to control its cytotoxicity, with optimal cell growth observed at BP concentrations as high as 500 ppm. These results reinforced that the supplementation of OPF with BPNSs can increase the osteogenic capacity of polymer scaffolds for use in bone tissue engineering.

2D phosphorene nanosheets, quantum dots, nanoribbons: synthesis and biomedical applications.

Phosphorene, also known as black phosphorus (BP), is a two-dimensional (2D) material that has gained significant attention in several areas of current research. Its unique properties such as outstanding surface activity, an adjustable bandgap width, favorable on/off current ratios, infrared-light responsiveness, good biocompatibility, and fast biodegradation differentiate this material from other two-dimensional materials. The application of BP in the biomedical field has been rapidly emerging over the past few years. This article aimed to provide a comprehensive review of the recent progress on the unique properties and extensive medical applications for BP in bone, nerve, skin, kidney, cancer, and biosensing related treatment. The details of applications of BP in these fields were summarized and discussed.

Mesenchymal stem cell spheroids incorporated with collagen and black phosphorus promote osteogenesis of biodegradable hydrogels.

Mesenchymal stem cell (MSC)-spheroids have sparked significant interest in bone tissue engineering due to their resemblance to natural bone tissue, especially in terms of cell-cell and cell-extracellular matrix interactions. Many biomaterials or biomolecules have been incorporated into MSC-spheroids to enhance their osteogenic abilities. In this respect, we assessed the osteogenic responses of MSC spheroids leveraged through the unique combination of collagen and black phosphorus (BP). The MSC spheroids were successfully constructed with 6 µg/mL collagen and/or a concentration gradient (0 µg/mL, 4 µg/mL, 8 µg/mL, and 16 µg/mL) of BP and were evaluated for MSC viability and their osteogenic differentiation over a time period of 14 days. Improved MSC viability and osteogenic ability were observed for the spheroids with collagen and BP at the concentration of 4 µg/mL and 8 µg/mL. Next, blank spheroids (Control) or the optimized MSC spheroids with 6 µg/mL collagen and 4 µg/mL BP (Col+BP4) were further encapsulated into two types of hydrogel scaffolds: porous oligo[poly(ethylene glycol) fumarate] (OPF) hydrogel and hydroxyapatite-collagen I scaffold (HE-COL). The osteogenic abilities of these four groups were evaluated after 14 and 21 days of osteogenic induction. The MSC spheroids incorporated with collagen and BP implanted into OPF porous hydrogel (Col+BP/OPF) elicited a higher expression of Runx2, osteopontin, and alkaline phosphatase than blank spheroids implanted into OPF porous hydrogel (Control/OPF). Enhanced osteogenesis was also observed in the Col+BP/HE-COL group as compared to Control/HE-COL. Taken together, the results from this study showed the perspectives of collagen and BP incorporated MSC spheroids for the development of injectable cellular therapies for bone regeneration.

Injectable Electrical Conductive and Phosphate Releasing Gel with Two-Dimensional Black Phosphorus and Carbon Nanotubes for Bone Tissue Engineering.

Injectable hydrogels have unique advantages for the repair of irregular tissue defects. In this study, we report a novel injectable carbon nanotube (CNT) and black phosphorus (BP) gel with enhanced mechanical strength, electrical conductivity, and continuous phosphate ion release for tissue engineering. The gel utilized biodegradable oligo(poly(ethylene glycol) fumarate) (OPF) polymer as the cross-linking matrix, with the addition of cross-linkable CNT-poly(ethylene glycol)-acrylate (CNTpega) to grant mechanical support and electric conductivity. Two-dimensional (2D) black phosphorus nanosheets were also infused to aid in tissue regeneration through the steady release of phosphate that results from environmental oxidation of phosphorus in situ. This newly developed BP-CNTpega-gel was found to enhance the adhesion, proliferation, and osteogenic differentiation of MC3T3 preosteoblast cells. With electric stimulation, the osteogenesis of preosteoblast cells was further enhanced with elevated expression of several key osteogenic pathway genes. As monitored with X-ray imaging, the BP-CNTpega-gel demonstrated excellent in situ gelation and cross-linking to fill femur defects, vertebral body cavities, and posterolateral spinal fusion sites in the rabbit. Together, these results indicate that this newly developed injectable BP-CNTpega-gel owns promising potential for future bone and broad types of tissue engineering applications.

Two-Dimensional Black Phosphorus and Graphene Oxide Nanosheets Synergistically Enhance Cell Proliferation and Osteogenesis on 3D Printed Scaffolds.

Two-dimensional (2D) materials have emerged as a new promising research topic for tissue engineering because of their ability to alter the surface properties of tissue scaffolds and thus improve their biocompatibility and cell affinity. Multiple 2D materials, such as graphene and graphene oxide (GO), have been widely reported to enhance cell adhesion and proliferation. Recently, a newly emerged black phosphorus (BP) 2D material has attracted attention in biomedical applications because of its unique mechanical and electrochemical characteristics. In this study, we investigated the synergistic effect of these two types of 2D materials on cell osteogenesis for bone tissue engineering. BP was first wrapped in negatively charged GO nanosheets, which were then adsorbed together onto positively charged poly(propylene fumarate) three-dimensional (3D) scaffolds. The increased surface area provided by GO nanosheets would enhance cell attachment at the initial stage. In addition, slow oxidation of BP nanosheets wrapped within GO layers would generate a continuous release of phosphate, an important osteoblast differentiation facilitator designed to stimulate cell osteogenesis toward the new bone formation. Through the use of 3D confocal imaging, unique interactions between cells and BP nanosheets were observed, including a stretched cell shape and the development of filaments around the BP nanosheets, along with increased cell proliferation when compared with scaffolds incorporating only one of the 2D materials. Furthermore, the biomineralization of 3D scaffolds, as well as cellular osteogenic markers, was all measured and improved on scaffolds with both BP and GO nanosheets. All these results indicate that the incorporation of 2D BP and GO materials could effectively and synergistically stimulate cell proliferation and osteogenesis on 3D tissue scaffolds.

Facile synthesis of gold nanorods/hydrogels core/shell nanospheres for pH and near-infrared-light induced release of 5-fluorouracil and chemo-photothermal therapy.

We described a facile synthesis of pH and near-infrared (NIR) light dual-sensitive core/shell hybrid nanospheres, consisting of gold nanorods (GNR) as the core and poly(N-isopropylacrylamide-co-methacrylic acid) as the shell, p(NIPAM-MAA). The resultant GNR/p(NIPAM-MAA) nanospheres showed a core/shell structure, with an average diameter of ∼110nm and a strong longitudinal surface plasmon band at NIR region. Due to the photothermal effect of GNR and pH/thermal-sensitive volume transition of p(NIPAM-MAA) hydrogels, the nanospheres with loading of 5-fluorouracil (5-FU) by electrostatic interactions were developed as a smart carrier for pH- and photothermal-induced release of 5-FU. Experimental results testified that the cumulative release of 5-FU from nanospheres was markedly increased in a mild acidic medium. Moreover, a NIR light (808nm) irradiation triggered a greater and faster release of 5-FU, which was further testified by relevant results from in vitro cytotoxicity assay, in vivo tumor growth inhibition and histological images of ex vivo tumor sections. These results revealed significant applications of GNR/p(NIPAM-MAA) nanospheres in controlled release of anticancer agents and photothermal ablation therapy of tumor tissues, accompanied by synergistic effect of chem-photothermal therapy.

Clinical systematic observation of Kangxin capsule curing vascular dementia of senile kidney deficiency and blood stagnation type.

OBJECTIVE: To observe the validity and safety of Kangxin capsule curing the patients with vascular dementia (VaD). PATIENTS AND METHODS: Fifty-six patients with vascular dementia of kidney deficiency and blood stagnation type were selected on the basis of defined diagnostic criteria and were randomly divided into Kangxin group (29) and control group (27), observing the relevant accumulation scores in dementia scale before and after treatment and changes of endothelin (ET), sex hormone, immunity and routine examinations. RESULTS: Kangxin capsule can effectively improve the symptom of patients with VaD of senile kidney deficiency and blood stagnation type, and the average value of curative effect index of 29 patients in the treatment group is 23.01>/=20%, i.e. effective; compared with that before treatment, both CD(4) and CD(4).CD(8)(-1) rises (P<0.05) after the treatment with Kangxin capsule; for the male VaD patients of the Kangxin group, T level increases (P<0.05) and estrodial (E(2)).testerone (T)(-1) value decreases (P<0.05) after the treatment; for the female VaD patients of the Kangxin group, E(2), E(2).T(-1) value increases a great deal (P<0.05) compared with that before treatment; ET level of both groups decreased on average (P<0.01), and did not demonstrate any obvious toxic side effect. CONCLUSIONS: Kangxin capsule is a valid and safe preparation of Chinese traditional medicine for curing VaD of senile kidney deficiency and blood stagnation type.