Characterization, biodegradability and blood compatibility of poly[(R)‐3‐hydroxybutyrate] based poly(ester‐urethane)s

Abstract

Poly(ester-urethane)s (PUs) were synthesized using hexamethylene diisocyanate (HDI) or toluene diisocyanate (TDI) to join short chains (M(n) = 2000) of poly(R-3-hydroxybutyrate) (PHB) diols and poly(epsilon-caprolactone) (PCL) diols with different feed ratios under different reaction conditions. The multiblock copolymers were characterized by nuclear magnetic resonance spectrometer (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM). XRD spectra and second DSC heat thermograms of the multiblock copolymers revealed that the crystallization of both PHB and PCL segments was mutually restricted, and, especially, the PCL segment limited the cold crystallization of the PHB segment. The SEM of platelet adhesion experiments showed that the hemocompatibility was affected to some extent by the chain flexibility of the polymers. Hydrolysis studies demonstrated that the hydrolytic degradation of PUs was generated from the scission of their ester bonds or/and urethane bonds. Simultaneously, the rate of ester bond scission was determined to some extent by the crystallization degree, which was further affected by the configuration of polymer chains. These highly elastic multiblock copolymers combining hemocompatibility and biodegradability may be developed into blood contact implant materials for biomedical applications.

Synthesis, characterizations, and biocompatibility of block poly(ester‐urethane)s based on biodegradable poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) and poly(ε‐caprolactone)

“…6), it is noted that with increase of PCL composition, the T g becomes lower. That may be due to the lower T g of PCL 11. When PCL segment is shorter, both PCL and P3/4HB segments possess lower mobility due to the urethane linkage.…”

“…One of our strategies is the synthesis of block copolymers based on PHA, with the emphasis on the block polyurethane copolymers. A series of block polyurethanes, triblock and star block copolymers have been prepared in our laboratory to explore the suitable biocompatibility and other properties in order to achieve practical biomaterials 10–15…”

Stereocomplexation in Copolymer Networks Incorporating Enantiomeric Glycerol-Based 3-Armed Lactide Oligomers and a 2-Armed ɛ-Caprolactone Oligomer

“…As the H3scLAO was obtained as a white powder, the formation of network structure was very important to produce a tough film. In addition, the crosslinking by urethane linkages is important to not spoil the biodegradable and biocompatible properties of the polyester segments [46,47]. …”

Synthetic routes to degradable copolymers deriving from the biosynthesized polyhydroxyalkanoates: A mini review

“…Moreover, nonbiodegradable PEG-PPG-PEG triblock copolymers have been reported to show hyperlipidemia and high plasma level of cholesterol in rabbits and rats [92], and less cells (L929 mouse fibroblasts) attachment [93], suggesting that introducing a hydrophilic, biodegradable and biocompatible soft phase in the PHAs block copolymers is an effective way to design novel biomaterials. Other diisocyanate, including toluene diisocyanate [94], 2,2,4-trimethylhexamethylene diisocyanate [95][96][97], and L-lysine methyl ester diisocyanate [96][97][98] have also been applied to synthesize block copolymer. The coupling reaction via diisocyanate must be carried out under anhydrous conditions and an argon or nitrogen atmosphere due to the moisture sensitivity of the coupling agent.…”