| ObjectivePoly N-isopropylacrylamide (PNIPAM) was synthesized and property test, biological detection and embolization in vitro by using it were performed to investigate its feasibility as a new embolic material. Rete mirabile (RMB) embolization by using PNIPAM in swine was performed to investigate technical feasibility, controllability and histopathological changes of PNIPAM for the treatment of cerebral arteriovenous malformations (AVM). Renal artery embolization by using PNIPAM was performed to investigate its embolic effectiveness and stability.Methods and materials 1.Laboratory StudyNIPAN and NNIPAM, in certain proportion, were dissolved in distilled water containing initiators in glass ampoules. Each ampoule was repeatedly evaluated, and then sealed and heated at 80°C for 6h. After polymerization, the residual monomer and initiators were removed. 1% solutions of the copolymers were mixed with iohexol and tantalum powder respectively, then were sterilized at 120°C for 30 min for further convery test in vitro. The copolymer of certain concentrations was put into thermostatic water bath for low critical solution temperature (LCST) determination. The molecular weight of the copolymer was given as following equation: [ η ]=14.5 × 10-2M0..5(ml/g). The rotational rheometer was utilized for rheology test, the converting infrared spectrometer was used for infrared spectrum of the working sample, the nuclear magnetic resonance spectrometer was used for detecting wave spectrum of the... |
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