Synthesis and Characterization of Photocrosslinkable Biodegradable Polymers Derived from 4‐Hydroxycinnamic Acid

Abstract

A novel series of photocrosslinkable biodegradable polymers was prepared by a high‐temperature solution polycondensation from a dichloride of 4,4′‐(adipoyldioxy)dicinnamic acid (CAC) and alkane diols of various methylene lengths (HO(CH2)nOH; n = 6–10) or poly(ethylene glycol)s (PEG) of various molecular weights $(\bar M = 200 - 8300)$. The CAC was synthesized by the condensation of adipoyl chloride and 4‐hydroxycinnamic acid. The chemical structures and properties of these polymers were characterized by elemental analysis, ultraviolet‐visible spectroscopy (UV‐VIS), Fourier transform infrared spectroscopy (FT‐IR), 1H NMR spectroscopy, differential scanning calorimertry (DSC), and thermogravimetry (TG). All polymers had a high molecular weight and good solubility in organic solvents. DSC showed that Tm values of CACn (134–180 °C) were much higher than those of CACEm (25–56 °C). The CACE200 degraded very rapidly in the buffer solutions (pH 7.2) of Ps. Cepacia or Rh. delemar lipase at 37 °C, while CACn resisted the hydrolysis by these lipases during the test period. The ultraviolet light irradiation (λ ≥ 280 nm) caused the photocrosslinking reaction by an intermolecular dimerization at ambient temperature without a photosensitizer, as examined by UV‐VIS, FT‐IR spectroscopy, and gel formation. The gels prepared from CACEm (m ≈ 1 000) were swollen in water and showed characteristic properties of a hydrogel. The irradiation time and the molecular weight of PEGs controlled the degree of swelling of these hydrogels. The CACE8 300 gel irradiated for 20 min showed the largest degree of swelling of 10.5.Weight loss of a CACE200 film as a function of time in a phosphate buffer solution containing no lipase (□), Ps. cepacia lipase (•), or Rh. delemar lipase (○) at 37 °C.magnified imageWeight loss of a CACE200 film as a function of time in a phosphate buffer solution containing no lipase (□), Ps. cepacia lipase (•), or Rh. delemar lipase (○) at 37 °C.

Biodegradable elastic photocured polyesters based on adipic acid, 4-hydroxycinnamic acid and poly(ε-caprolactone) diols

“…CAC/PCL3000, which would be responsible for the lower concentration of cinnamoyl groups in the polymer. The similar behaviors has been observed for the polymers prepared from CAC and poly(ethylene glycol) [14].…”

“…The other reagents such as chloroform and n-hexane were purified by the standard procedure. 4,4 0 -(Adipoyldioxy)-dicinnamic acid (CAC) and diacyl chloride of CAC were synthesized as described in the previous paper [14]. Poly(1-caproactone) (M n ¼ 50; 400; M w =M n ¼ 1:55; polystyrene standards) was gifted from Daicel Chemical Co. Ltd. Poly(1-caprolactone) diols (PCLdiol) [a-v-dihydroxy poly(1-caprolactone)] of the number average molecular weight of 1250, 2000 and 3000 were supplied by Aldrich Co. Ltd with the following formula: H½ -OðCH 2 Þ 5 CO -n OðCH 2 CH 2 OÞ 2 ½ -COðCH 2 Þ 5 O -m H: These prepolymers were dried over P 2 O 5 at ambient temperature in vacuo.…”

“…Recently, biodegradable photocrosslinkable copolyesters composed of 4-hydroxycinnamic acid (HCA) and DL-lactic acid have been prepared [13]. We have synthesized the biodegradable polyesters based on adipic acid, HCA and poly(ethylene glycol)s, which were photocured to yield the hydrogels [14].…”

Bio-based Polymer from Ferulic Acid by Electropolymerization

“…Ferulic acid has many physiological functions including antimicrobial, anti-oxidant, anti-thrombotic, and carcinostatic activities; it has been studied for its applications in the food, cosmetic, and pharmaceutical fields (Ou and Kwok 2004;Pei et al 2015;Takahashi et al 2015). Bioactive polymers, which are based on ferulic acid, can also be prepared by incorporating ferulic acid into the polymer backbone, which can be regenerated again via biodegradation (Nagata and Hizakae 2003;Ouimet et al 2015Ouimet et al , 2013. However, these conversion processes involve several steps.…”

Studies on photoreactive and biodegradable copolymers composed of poly(ɛ-caprolactone) and 4-hydroxycinnamic acid

“…[17][18][19][20] The photoreactivity of the produced PCL-co-P4HCA copolymers was examined in THF solutions at room temperature by UV-visible spectrophotometery. Figure 3b shows the changes in the UV absorption of the PCL-co-P4HCA12 polymer during UV irradiation at l ¼ 302 nm as a function of irradiation time.…”