Material Flow analysis of plastics from provincial household appliances in China: 1978-2016.

China has the highest level of plastic production and consumption in the world. The plastic waste ban has resulted in a lack of raw materials for plastic reprocessing, while household appliance-related plastic (HAP), as a high-value and high-quality plastic waste source, receives great attention to fill such a gap. As HAP is scattered and has been rapidly increasing, a better understanding of the spatial-temporal patterns of HAP waste is critical. For the first time, this study quantifies the stocks and flows of plastics contained in five categories of household appliances (refrigerator, washing machine, air conditioner, TV, and computer) in China over 1978-2016 and maps their province-specific distribution through a dynamic stock-driven material flow analysis model. We find that (i) the HAP stocks are growing rapidly to reach around 25.4 million tonnes (MT) in 2016 and the HAP waste generated in 2016 is over 2 MT while the dismantling capacity is failing to catch up; (ii) the HAP waste in southeastern provinces is notably more than in northwestern provinces by approximately 11 times; (iii) washing machines (37%) and refrigerators (24%) are the major types of household appliances that contribute most to HAP waste generation; (iv) PP (38%) and PS (34%) are the major plastic types in HAP waste. These findings can provide quantitative references for the government to arrange waste management facilities, improve recycling capacities of dismantling companies, and promote coordinated efforts from multiple stakeholders to achieve efficient waste management of HAP.

[Determination of six lignin components in crude and different processed products of Schisandra chinensis].

OBJECTIVE: To compare the contents of lignin in crude and processed fruits of Schisandrae chinensis, and to explore the processing mechanism of S. chinensis fruits. METHOD: Contents of schisandrin, schisandrol B, deoxyschisandrin, gomisin N, gamma-schizandrin and schisandrin C were determined by high performance liquid chromatography (HPLC). RESULT: Except the content of Schisandrol B was higher or less in processed fruits than that in the crude, the other lignin contents of S. chinensis fruits in different processed products were higher than that in the crude. The alcohol-processed product had the highest content of lignin. CONCLUSION: The contents of lignin have changed by different processed methods, and alcohol-processed method may be the best processed method.

Exploration of the antibacterial and wound healing potential of a PLGA/silk fibroin based electrospun membrane loaded with zinc oxide nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are known for their antibacterial, antioxidant, and anti-inflammatory activities. Moreover, ZnO NPs can stimulate cell migration, re-epithelialization, and angiogenesis. All these attributes are highly relevant to wound healing. Local administration of ZnO NPs to the wound can be achieved through electrospun nanofibers. We hypothesized that the use of poly(lactide-co-glycolic acid) (PLGA)/silk fibroin (SF) nanofiber-based delivery of ZnO would maintain the bioavailability of NPs on the wound area and synchronization with the unique structural features of electrospun nanofibers, could stimulate wound closure, re-epithelialization, collagen deposition, cellular migration, and angiogenesis. In this study, we fabricated PLGA/SF (PS) nanofibrous (NF) membranes with and without ZnO NPs and extensively characterized them for various physicochemical and biological attributes. Scanning electron microscopy (SEM) revealed smooth fibers and ZnO concentration-dependent increase in the fiber diameter. Transmission electron microscopy (TEM) also confirmed the encapsulation of ZnO NPs in the polymer matrix. The successful loading of ZnO was further confirmed by X-ray diffraction. Furthermore, mechanical testing revealed a ZnO concentration-dependent increase in the tensile strength. Moreover, biocompatibility was evaluated through in vitro cell culture. A mild anti-oxidant activity was also noted mainly due to the presence of silk fibroin. In vitro antibacterial tests revealed a ZnO concentration-dependent increase in antibacterial activity and PLGA/SF/3% ZnO (PSZ3) remained completely active against E. coli and S. aureus. More importantly, NF membranes were evaluated for their in vivo wound healing potential. The PSZ3 NF membrane not only facilitated the early wound closure but also remarkably enhanced the quality of wound healing confirmed through histopathological analysis. Re-epithelialization, granulation tissue formation, collagen deposition, and angiogenesis are some of the key parameters significantly boosted by ZnO loaded composite NF membranes. Based on extensive characterization and biological evaluation, the PSZ3 NF membrane has turned out to be a potential candidate for wound healing applications.

A novel elastic and controlled-release poly(ether-ester-urethane)urea scaffold for cartilage regeneration.

In the tissue engineering of cartilage, scaffolds with appropriate elasticity and controlled-release properties are essential. Herein, we synthesized a poly(ether-ester-urethane)urea scaffold with a pendant amino group (PEEUUN) through a de-protection process from PEEUU-Boc polymers and grafted kartogenin (KGN) onto the PEEUUN scaffolds (PEEUUN-KGN). Characterization, performance tests, scaffold biocompatibility analysis, and chondrogenesis evaluation both in vitro and in vivo were conducted. The results revealed that the PEEUUN-KGN scaffolds were degradable and three-dimensional (3D) with interconnected pores, and possessed good elasticity, as well as excellent cytocompatibility. Meanwhile, KGN on the PEEUUN-KGN scaffolds underwent stable sustained release for a long time and promoted human umbilical cord mesenchymal stem cells (HUCMSCs) to differentiate into chondrocytes in vitro, thus enhancing cartilage regeneration in vivo. In conclusion, the present PEEUUN-KGN scaffolds would have application potential for cartilage tissue engineering.