1 research outputs found
Protein Microspheres with Unique Green and Red Autofluorescence for Noninvasively Tracking and Modeling Their in Vivo Biodegradation
Bovine
serum albumin (BSA) microspheres were prepared through a
facile and low-cost route including a high-speed dispersion of BSA
in cross-linking solution followed by spray drying. Interestingly
the as-prepared BSA microspheres possess unique blue-green, green,
green-yellow, and red fluorescence when excited by specific wavelengths
of laser or LED light. The studies of UV–visible reflectance
spectra and fluorescence emission spectra indicated that four classes
of fluorescent compounds are presumably formed during the fabrication
processes. The formation and the potential contributors for the unique
green and red autofluorescence were also discussed and proposed though
the exact structures of the fluorophores formed remain elusive due
to the complexity of the protein system. The effect of spray-drying
conditions on the morphology of spray-dried samples was investigated
and optimized. FTIR was further employed to characterize the formation
of the functional groups in the as-prepared autofluorescent microspheres.
Good in vitro and in vivo biocompatibility was demonstrated by the
cytotoxicity test on the A549 cancer cells and tissue histological
analysis, respectively. The autofluorescent BSA microspheres themselves
were then applied as a novel tracer for convenient tracking/modeling
of the biodegradation of autofluorescent BSA microspheres injected
into mouse model based on noninvasive, time-dependent fluorescence
images of the mice, in which experimental data are in good agreement
with the proposed mathematical model. All these studies indicate that
the as-developed protein microspheres exhibiting good biocompatibility,
biodegradability, and unique autofluorescence, can significantly broaden
biomedical applications of fluorescent protein particles