The effect of substitution levels on the luminescent and degradation properties of fluorescent poly(ester‐anhydride)s

Abstract

ABSTRACT:In this work, two kinds of diacid monomers were synthesized by a convenient scheme, where 4-hydroxy-3-methoxybenzoic acid (vanillic acid) or 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid) directly condensated with succinic chloride. Corresponding polyanhydrides were obtained by melt polycondensation. Copolyanhydrides composed of the new monomers and sebacic acid (SA) were further prepared and characterized by NMR, DSC, and fluorometer. The two new kinds of polyanhydride emit strong fluorescence and have similar fluorescent spectra to poly(di(p-carboxyphenyl) succinate anhydride) (P(d-CPS)). The emission wavelength ( em ) of the copolymers could be tuned by the excitation wavelength ( ex ). Degradation rate of the copolyanhydrides decreased as dMOCPS or ddMOCPS fraction increased, and the degradation duration could be modulated from several days to more than 3 months. It addition, the copolyanhydrides displayed typical surface-degradation characteristics.

Phenolic Acid‐based Poly(anhydride‐esters) as Antioxidant Biomaterials

“…Solution polymerization was chosen after melt‐condensation polymerization attempts with SGA (adipic) diacid resulted in rapid vitrification, yielding oligomers. This occurrence is consistent with previous literature using similar SGA‐based diacids . 1 H NMR spectra signified successful polymerization through the upfield shift and broadening of the aromatic peaks (Figure C), while FTIR spectra revealed the disappearance of the C═O acid stretch and appearance of the anhydride peaks at 1783 and 1724 cm −1 (Figure B ).…”

“…Increasing methoxy content, when comparing different bioactives with the same linker molecule (i.e., 4a vs. 4c ), also resulted in an increased T d . The impact of methoxy substitution on T g via increasing chain rigidness has previously been observed in polymer systems, while methoxy‐substitution trends regarding , T g , and T g are concurrent with previous PAEs …”

“…VA and SGA‐based diacids ( 3a‐d ) were synthesized following previously established protocols, in which pyridine was first reacted with an acyl chloride to generate a pyridinium ion that selectively reacted with the phenol of VA or SGA ( 1 , Scheme ). Diacids were isolated in high yields (84 to 93%), and their chemical structures and composition were confirmed by NMR spectroscopy, FTIR spectroscopy, and elemental analysis.…”

“…Miller et al synthesized VA‐ and SGA‐containing polyesters; however, the bioactive in these systems was conjugated through water‐stable ether bonds . Similarly, biodegradable VA‐containing copolyesters as well as VA‐ and SGA‐containing random copolyanhydrides have been synthesized, but their bioactive release and biological activity have not been evaluated …”

Degradable polyprodrugs: design and therapeutic efficiency

“…23c). 162 Increasing the content of sebacic acid in the polyprodrug led to an increase of hydrophobicity, inducing a significant reduction of degradation rate. The nature of the linkers between hydroxy-acid drugs in poly(anhydride–ester)s has also an influence on the degradability of the polymers.…”