Current Advances towards 4-Hydroxybutyrate Containing Polyhydroxyalkanoates Production for Biomedical Applications

Abstract

Polyhydroxyalkanoates (PHA) are polyesters having high promise in biomedical applications. Among different types of PHA, poly-4-hydroxybutyrate (P4HB) is the only polymer that has received FDA approval for medical applications. However, most PHA producing microorganisms lack the ability to synthesize P4HB or PHA comprising 4-hydroxybutyrate (4HB) monomer due to their absence of a 4HB monomer supplying pathway. Thus, most microorganisms require supplementation of 4HB precursors to synthesize 4HB polymers. However, usage of 4HB precursors incurs additional production cost. Therefore, researchers have adopted strategies to reduce the cost, such as utilizing low-cost substrate as well as constructing 4HB monomer supplying pathways in microorganisms. We herein summarize the biomedical applications of P4HB, the natural producers of 4HB polymer, and the various strategies that have been applied in producing 4HB polymers in non-4HB producing microorganisms. It is expected that the readers would gain a vivid idea on the different strategic developments in the field of 4HB polymer production.

Sustainable bioconversion of synthetic plastic wastes to polyhydroxyalkanoate (PHA) bioplastics: recent advances and challenges

“…The SSA is reduced to 4HB by 4HB dehydrogenase. 163 2.4′ -Toluene Diamine (TDA) is oxidized, decarboxylated, and deaminated to form 4-amino-catechol, which may be converted into 5-amino-2-hydroxyl muconic acid in the form of diol, and then degraded and transformed through a metabolic pathway similar to catechuic acid (reviewed by). 67 EG can be used as a substrate for the production of PHA and glyoxylic acid, which have a wide range of applications in the chemical industry.…”

Study on the production of high 3HV content PHBV via an open fermentation with waste silkworm excrement as the carbon source by the haloarchaeon Haloferax mediterranei

“…Compared with traditional petroleum-based plastics, PHA-based plastics have advantages for biocompatibility and good barrier properties ( Cavalheiro et al, 2012 ). They can be extensively applied in biomedicine field ( Mitra et al, 2021 ), such as cartilage repair and vascular scaffolds ( Albuquerque and Malafaia, 2018 ). Therefore, PHAs are considered as environmentally friendly substitute for petroleum-based plastics ( Benesova et al, 2017 ).…”