Tailored Biodegradable and Electroactive Poly(hydroxybutyrate-co-hydroxyvalerate) Based Morphologies for Tissue Engineering Applications

Abstract

Polymer-based piezoelectric biomaterials have already proven their relevance for tissue engineering applications. Further, the morphology of the scaffolds plays also an important role in cell proliferation and differentiation. The present work reports on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), a biocompatible, biodegradable and piezoelectric biopolymer that has been processed in different morphologies, including films, fibres, microspheres and 3D scaffolds. Further, the corresponding magnetically active PHBV-based composites were also produced. The effect of the morphology on physico-chemical, thermal, magnetic and mechanical properties of pristine and composites samples was evaluated, as well as their cytotoxicity. It was observed that the morphology does not strongly affect the properties of the pristine samples but the introduction of cobalt ferrites induces changes in the degree of crystallinity that could affect the applicability of prepared biomaterials. Young modulus is dependent of the morphology and also increases with the addition of cobalt ferrites. Both, pristine and PHBV/cobalt ferrite composite samples are no cytotoxic, indicating their suitability for tissue engineering applications.

Piezoelectric biodegradable poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) based electrospun fiber mats with tailored porosity

“…Absorption bands at 820–979 and 1227–1478 cm −1 identify the aliphatic CH vibrational modes, whereas the vibration bands corresponding to CO vibrations are found at 1057, 1133, and 1183 cm −1 and the ones of C═O stretching at 1720 cm −1 . Finally, the absorption bands at 2885, 2928, and 2976 cm −1 are attributed to the stretching of the CH groups 40,41 …”

“…Figure 4B shows the DSC thermogram of the different samples, which are characterized by an endothermic peak between 170 and 180°C corresponding to the melting peak of PHBV 40 . The fibers composed by PHBV/PEO show an additional endothermic peak between 60 and 70°C, attributed to the melting peak of PEO 41 .…”

“…Neat and blend fibers produced with different solvents ratios (CF and CF/DMF) were obtained through electrospinning technique, as described in Reference 40. Briefly, neat PHBV and blend PHBV/PEO were prepared with CF and different solvent ratios of the CF/DMF binary solvent mixture, as presented in Table 1, under constant magnetic stirring at 40°C to obtain a 15% wt/vol polymer concentration.…”

“…where represents the experimental melting enthalpy (J.g −1 ), the theoretical enthalpy of a 100% crystalline polymer (146.6 and 196.8 J.g −1 for PHBV and PEO, respectively 40,41 ) and the weight fraction of PHBV or PEO in the mixture 41 . Thus, for blend samples, χ was normalized with respect to the content of the corresponding component.…”

Three-Dimensional Printed and Biocompatible Conductive Composites Comprised of Polyhydroxybutyrate and Multiwalled Carbon Nanotubes

“…11 Although it can be enzymatically degraded in the environment, PHB is not degradable under most conditions inside the body; therefore, PHB can be a good candidate for bioelectronics and implants as the designed products are expected to be stable and to elicit a low foreign body response. 11,12 Its monomer, hydroxybutyryl-CoA, produced bacterially through a fermentation process utilizing agricultural waste as the source, is found in all living cells. 13 In addition, PHB is mildly piezoelectric, producing small electric potentials upon mechanical stimulation.…”