Injectable and thermosensitive hydrogels mediating a universal macromolecular contrast agent with radiopacity for noninvasive imaging of deep tissues  

作　　者：Xiaohui Wu Xin Wang Xiaobin Chen Xiaowei Yang Qian Ma Guohua Xu Lin Yu Jiandong Ding 

机构地区：[1]State Key Laboratory of Molecular Engineering of Polymers,Department of Macromolecular Science,Shanghai Stomatological Hospital,Fudan University,Shanghai,200438,China [2]Department of Orthopedic Surgery,Spine Center,Changzheng Hospital,Naval Medical University,Shanghai,200003,China [3]Zhuhai Fudan Innovation Institute,Zhuhai,Guangdong,519000,China

出　　处：《Bioactive Materials》2021年第12期4717-4728,共12页生物活性材料（英文）

基　　金：Authors acknowledge funding from the National Natural Science Foundation of China(grant Nos.51773043,81772363 and 21975045);the National Key R&D Program of China(grant Nos.2020YFC1107102 and 2016YFC1100300).

摘　　要：It is very challenging to visualize implantable medical devices made of biodegradable polymers in deep tissues.Herein,we designed a novel macromolecular contrast agent with ultrahigh radiopacity(iodinate content>50%)via polymerizing an iodinated trimethylene carbonate monomer into the two ends of poly(ethylene glycol)(PEG).A set of thermosensitive and biodegradable polyester-PEG-polyester triblock copolymers with varied polyester compositions synthesized by us,which were soluble in water at room temperature and could spontaneously form hydrogels at body temperature,were selected as the demonstration materials.The addition of macromolecular contrast agent did not obviously compromise the injectability and thermogelation properties of polymeric hydrogels,but conferred them with excellent X-ray opacity,enabling visualization of the hydrogels at clinically relevant depths through X-ray fluoroscopy or Micro-CT.In a mouse model,the 3D morphology of the radiopaque hydrogels after injection into different target sites was visible using Micro-CT imaging,and their injection volume could be accurately obtained.Furthermore,the subcutaneous degradation process of a radiopaque hydrogel could be non-invasively monitored in a real-time and quantitative manner.In particular,the corrected degradation curve based on Micro-CT imaging well matched with the degradation profile of virgin polymer hydrogel determined by the gravimetric method.These findings indicate that the macromolecular contrast agent has good universality for the construction of various radiopaque polymer hydrogels,and can nondestructively trace and quantify their degradation in vivo.Meanwhile,the present methodology developed by us affords a platform technology for deep tissue imaging of polymeric materials.

关 键 词：Thermosensitive hydrogels RADIOPACITY Block copolymers In vivo degradation Non-invasive deep tissue imaging 

分 类 号：R318.08[医药卫生—生物医学工程]