Suchergebnisse

Wei Xiong,1,2 Lixia Peng,1,2 Hongbo Chen,3 Qin Li1,2 1Southern Medical University, Guangzhou, 2Department of Plastic Surgery, General Hospital of Guangzhou Military Command of PLA, Guangzhou, People's Republic of China; 3Division of Life Sciences and Health, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China Abstract: To enhance the therapeutic effects of chemotherapy on malignant melanoma, paclitaxel (PTX)-loaded methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) nanoparticles (MPEG-b-PCL NPs) that had their surfaces modified with polydopamine (PTX-loaded MPEG-b-PCL NPs@PDA) were prepared as drug vehicles. The block copolymer MPEG-b-PCL was synthesized by ring-opening polymerization and characterized by proton nuclear magnetic resonance spectroscopy and gel permeation chromatography. The PTX-loaded NPs were prepared by a modified nanoprecipitation technique. The PTX-loaded NPs and PTX-loaded NPs@PDA were characterized in terms of size and size distribution, zeta potential, surface morphology, drug encapsulation efficiency, and drug release. Confocal laser scanning microscopy showed that coumarin-6-loaded NPs@PDA could be internalized by human melanoma cell line A875 cells. The cellular uptake efficiency of NPs was greatly enhanced after PDA modification. The antitumor efficacy of the PTX-loaded NPs@PDA was investigated in vitro by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and in vivo by a xenograft tumor model. The PTX-loaded NPs@PDA could significantly inhibit tumor growth compared to Taxol® and precursor PTX-loaded NPs. All the results suggested that the PTX-loaded MPEG-b-PCL NPs that had their surfaces modified with PDA are promising nanocarriers for malignant melanoma therapy. Keywords: cancer nanotechnology, drug delivery, surface modification, polydopamine, malignant melanoma

In an effort to address climate change, in 2013 China launched the world's largest government-driven carbon emission reduction programme, the National Low Carbon Industrial Parks Pilot Programme (LCIPPP). This paper analyses this newly developed pilot program. To deepen our understanding of the causes and the impact of industrial park CO2 emissions, we use the STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model and data from 20 pilot industrial parks involved in the LCIPPP for the period 2012–2016. This study quantitatively evaluates the effect of CO2 emissions on output, energy structure, energy intensity, industrial structure, R&D intensity, and population change in different regions and nationally through an elasticity coefficient method. The results confirm that an increase in output and energy intensity is a dominant contributor to the growth of CO2 emissions whereas an increase of the share of tertiary industry and R&D intensity has significant effects on reducing CO2 emissions. The elasticity of energy intensity and renewable energy consumption on CO2 emissions in the eastern region of China is the highest, indicating that using renewable energy to reduce CO2 emissions for the industrial parks is more effective in the eastern region as compared to the central and western regions of the country. The elasticity of population is significantly negative in both the central and western areas while it is positive in eastern part of China, thereby illustrating that promoting labour intensive industries will be an effective way to reduce CO2 emissions for the industrial parks in China's central and western regions. Our study reveals that differentiated low carbon development pathways should be adopted. Concrete policy implications for reducing CO2 emissions are also provided.