title: Visualization of in vivo degradation of aliphatic polyesters by a fluorescent dendritic star macromolecule.
abstract: In tissue engineering, most polymeric scaffolds should degrade along with the formation of the new tissues. Therefore, it is necessary to look into the in vivo degradation of scaffolds. In this study, a fluorescent perylenediimide-cored (PDI-cored) dendritic star macromolecule bearing multiple amines (d-p48) was incorporated into biodegradable polyester nanofibrous scaffolds by eletrospinning as an indicator. The polyester/d-p48 blend nanofibers could emit strong red fluorescence when they were irradiated under exciting light. Initially, using slowly degradable polyester, poly(L-lactide) (PLLA)/d-p48 nanofibers were soaked in phosphate buffered saline for various lengths of time to determine the possible diffusing release of d-p48 macromolecule from nanofibers. The PLLA/d-p48 nanofibers were then implanted subcutaneously into mice and left for up to 2 weeks. In both cases, no undesirable release of the incorporated d-p48 macromolecule was detected, and the nanofibers were clearly visualized in vivo by fluorescence microscopy. Using a fast degradable polyester, poly(lactide-co-glycolide) (PLGA)/d-p48 nanofibers were electrospun and implanted subcutaneously to determine the possibility of monitoring in vivo degradation by fluorescence during 12 weeks. The results showed that the location and the contour of PLGA/d-p48 nanofibrous scaffolds could be clearly visualized using an animal fluorescent imaging system. The fluorescent intensities decreased gradually with the degradation of the scaffolds. No side effects on liver and kidney were found during the detection. This study indicates that the fluorescent PDI-cored dendritic star macromolecule can be used as a stable bioimaging indicator for biodegradable aliphatic polyesters in vivo.
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Shun
authors.initials: S
authors.lastname: Duan
authors.forename: Shiqing
authors.initials: S
authors.lastname: Ma
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Huang
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yang
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.forename: Meizhen
authors.initials: M
authors.lastname: Yin
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D050091:Dendrimers / Q000032:analysis / Q000138:chemical synthesis* / Q000633:toxicity; D004343:Drug Implants / Q000032:analysis / Q000138:chemical synthesis* / Q000633:toxicity; D019544:Equipment Failure Analysis / Q000379:methods; D005456:Fluorescent Dyes / Q000032:analysis / Q000138:chemical synthesis* / Q000633:toxicity; D008422:Materials Testing; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D050091:Dendrimers; D004343:Drug Implants; D005456:Fluorescent Dyes