Degradation of P(3HB-co-4HB) Films in Simulated Body Fluids

Abstract

A novel model of biodegradable PHA copolymer films preparation was applied to evaluate the biodegradability of various PHA copolymers and to discuss its biomedical applicability. In this study, we illustrate the potential biomaterial degradation rate affectability by manipulation of monomer composition via controlling the biosynthetic strategies. Within the experimental investigation, we have prepared two different copolymers of 3-hydroxybutyrate and 4-hydroxybutyrate—P(3HB-co-36 mol.% 4HB) and P(3HB-co-66 mol.% 4HB), by cultivating the thermophilic bacterial strain Aneurinibacillus sp. H1 and further investigated its degradability in simulated body fluids (SBFs). Both copolymers revealed faster weight reduction in synthetic gastric juice (SGJ) and artificial colonic fluid (ACF) than simple homopolymer P3HB. In addition, degradation mechanisms differed across tested polymers, according to SEM micrographs. While incubated in SGJ, samples were fragmented due to fast hydrolysis sourcing from substantially low pH, which suggest abiotic degradation as the major degradation mechanism. On the contrary, ACF incubation indicated obvious enzymatic hydrolysis. Further, no cytotoxicity of the waste fluids was observed on CaCO-2 cell line. Based on these results in combination with high production flexibility, we suggest P(3HB-co-4HB) copolymers produced by Aneurinibacillus sp. H1 as being very auspicious polymers for intestinal in vivo treatments.

Effects of Differing Monomer Compositions on Properties of P(3HB-co-4HB) Synthesized by Aneurinibacillus sp. H1 for Various Applications

“…In our previous study (see Ref. [ 10 ]), we reported the high biodegradability of tested copolymers in simulated physiological environments and found no cytotoxicity of the degradation products. A combination of these outputs shows great usability of tested P(3HB- co -4HB) copolymers in biomedicine and foodstuff or cosmetics packaging.…”

“…Preparation of the PHAs and polymer films was previously described in [ 10 ]. For the purpose of PHAs production, two bacterial strains were employed— Cupriavidus necator H16 for P(3HB) biosynthesis and Aneurinibacillus sp.…”

“…Preparation of the PHAs and polymer films was previously described in [ 10 ]. Briefly, extracted polymeric materials were dissolved in chloroform to 5% w/w concentration.…”

“…The method for the average molecular weight determination was described previously [ 10 ]. Samples of films were dissolved in HPLC-grade chloroform at a concentration of 1.5 mg/mL.…”

Production of Various Monomer-Ratio Biodegradable Poly(3-hydroxybutyrate-<em>co</em>-4-hydroxybutyrate) Films for Wide Range of Applications

“…Polymer materials used for this study correspond to materials used for degradation tests published previously [8]. The materials production was provided by the same procedures.…”