Nanoparticle-mediated small interfering RNA (siRNA) delivery is a promising therapeutic strategy in various cancers. However, it is difficult to deliver degradative siRNA to tumor tissue, and thus a safe and efficient vector for siRNA delivery is essential for cancer therapy. In this study, poly(ethylene glycol)-modified chitosan (PEG-CS) was synthesized successfully for delivering nucleic acid drug. We deemed that PEGylated CS could improve its solubility by forming a stable siRNA loaded in nanoparticles, and enhancing transfection efficiency of siRNA-loaded CS nanoparticles in cancer cell line. The research results showed that siRNA loaded in PEGylated CS (PEG-CS/siRNA) nanoparticles with smaller particle size had superior structural stability in the physical environment compared to CS nanoparticles. The data of in vitro antitumor activity revealed that 4T1 tumor cell growth was significantly inhibited and cellular uptake of PEG-CS/siRNA nanoparticles in 4T1 cells was dramatically enhanced compared to naked siRNA groups. The results from flow cytometry and confocal laser scanning microscopy showed that PEG-CS/siRNA nanoparticles were more easily taken up than naked siRNA. Importantly, PEG-CS/siRNA nanoparticles significantly reduced the growth of xenograft tumors of 4T1 cells in vivo. It has been demonstrated that the PEG-CS is a safe and efficient vector for siRNA delivery, and it can effectively reduce tumor growth and prevent metastasis.
Ma Yanyan,Li Jifeng,Ding Tao,Feng Qichun,Du Zhaofang
Water loss rate is crucial in evaluating the efficiency of atmospheric water harvesting (AWH) materials. However, most moisture-absorbing salts and gels have fixed heat transfer rates, limiting the development of high-performance AWH materials. Herein, an anisotropic PEG/CS/MF nanocomposite (APCM) with adjustable thermal transfer efficiency is presented. APCM was synthesized using polyethylene glycol (PEG), melamine foam (MF), and chitosan (CS) solution through a freeze orientation method. The resulting material exhibits a stable oriented laminated structure formed by hydrogen bonding between PEG, CS, and MF. This unique structure imparts excellent mechanical properties. APCM’s large lamellar gaps and pore diameters enable rapid absorption of atmospheric water molecules at low temperatures without leakage (61.79 kg m −3 ). The compressible nature of APCM allows for efficient heat transfer at high temperatures, and the release of 80% of absorbed water within 15 min. In a proof-of-concept demonstration using a custom-built AWH device, each cubic meter of APCM achieved three AWH cycles within 24 h, producing over 185 kg of water. Therefore, this innovative design offers a promising solution for enhancing the efficiency of AWH, potentially addressing water scarcity issues in various regions.
危险品化学品经营许可证（带存储）