Synthesis, applications and biosafety evaluation of carbon dots derived from herbal medicine.

Carbon dots (CDs) are novel zero-dimensional spherical nanoparticles with water solubility, biocompatibility and photoluminescence properties. As the variety of raw materials for CDs synthesis becomes more and more abundant, people tend to choose precursors from nature. Many recent studies have shown that CDs can inherit properties similar to their carbon sources. Chinese herbal medicine has a variety of therapeutic effects to many diseases. In recent years, many literatures have chosen herbal medicine as raw materials, however, how the properties of raw materials affect CDs has not been systematically summarized. The intrinsic bioactivity and potential pharmacological effects of CDs have not received sufficient attention and have become a 'blind spot' for research. In this paper, the main synthesis methods were introduced and the effects of carbon sources from different herbal medicine on the properties of CDs and related applications were reviewed. In addition, we briefly review some of the biosafety assessments of CDs, and make recommendations for biomedical applications. CDs that inherit the therapeutic properties of herbs can enable diagnosis and treatment of clinical diseases, bioimaging, and biosensing in the future.

Recent advances in carbon dots: synthesis and applications in bone tissue engineering.

Bone tissue engineering (BTE), based on the perfect combination of seed cells, scaffold materials and growth factors, has shown unparalleled potential in the treatment of bone defects and related diseases. As the site of cell attachment, proliferation and differentiation, scaffolds composed of biomaterials play a crucial role in BTE. Over the past years, carbon dots (CDs), a new type of carbon-based nanomaterial, have attracted extensive research attention due to their good biocompatibility, unique optical properties, and abundant functional groups. This paper reviews recent research progress in the use of CDs in the field of BTE. Firstly, different preparation methods of CDs are summarized. Then, the properties and categories of CDs applied in BTE are described in detail. Subsequently, the applications of CDs in BTE, including osteogenesis, fluorescence tracing, phototherapy and antibacterial activity, are presented. Finally, the challenges and future perspectives of CDs in BTE are briefly discussed to give a comprehensive picture of CDs. This review provides a theoretical basis and advanced design strategies for the application of CDs in BTE.

Presence, distribution and risk assessment of polycyclic aromatic hydrocarbons in rice-wheat continuous cropping soils close to five industrial parks of Suzhou, China.

Polycyclic aromatic hydrocarbons (PAHs) accumulated in agricultural soils are likely to threaten human health and ecosystem though the food chain, therefore, it is worth to pay more attention to soil contamination by PAHs. In this study, the presence, distribution and risk assessment of 16 priority PAHs in rice-wheat continuous cropping soils close to industrial parks of Suzhou were firstly investigated. The concentrations of the total PAHs ranged from 125.99 ng/g to 796.65 ng/g with an average of 352.94 ng/g. Phenanthrene (PHE), fluoranthene (FLT), benzo [a] anthracene (BaA) and pyrene (PYR) were the major PAHs in those soil samples. The highest level of PAHs was detected in the soils around Chemical plant and Steelworks, followed by Printed wire board, Electroplate Factory and Paper mill. The composition of PAHs in the soils around Chemical plant was dominated by 3-ring PAHs, however, the predominant compounds were 4, 5-ring PAHs in the soils around other four factories. Meanwhile, the concentration of the total PAHs in the soils close to the factories showed a higher level of PAHs in November (during rice harvest) than that in June (during wheat harvest). Different with other rings of PAHs, 3-ring PAHs in the soils around Chemical plant and Steelworks had a higher concentration in June. The results of principal component analysis and isomeric ratio analysis suggested that PAHs in the studied areas mainly originated from biomass, coal and petroleum combustion. The risk assessment indicated that higher carcinogenic risk was found in those sites closer to the industrial park.