Noninvasive biosensing 3D scaffold to monitor degradation: The potential of fluorescent PCL and PLGA for tissue engineering

The nondestructive localization and traceability of polymers by fluorescent tagging has become a valuable tool for biomedical applications. Integration of fluorescent molecule to the pristine polymers could modify polymers' degradation rate which is still unpredictable from a scaffold application standpoint. The current study focused to understand the material perspective of fluorescently tagged biodegradable polymers such as polycaprolactone (PCL) and poly (d,l-lactide-co-glycolide) (PLGA) with fluorescein amine isomer I (FITC). PCL-FITC and PLGA-FITC were characterized using FTIR for surface chemistry analysis and rheology for their mechanical properties. The grafted materials were utilized to form 3-dimentional scaffolds, and their degradation was monitored under accelerated degradation conditions triggered by pH. It was found that PCL and PCL-FITC had a very slow degradation rate, when compared to PLGA and PLGA-FITC. Both the FITC tagged materials displayed a faster degradation rate compared to their respective pristine material. Biocompatibility of the FITC conjugated polymers was tested using human-adipose derived stem cells (hADSCs) revealing that the sub products from the degradation of the polymers over 7 days did not negatively affect the cellular metabolic activity. This work highlights the significance of initial characterization of fluorescent modified polymers for future biomedical application.