Effects of ( R )-3-hydroxyhexanoate units on thermal hydrolysis of poly(( R )-3-hydroxybutyrate-co-( R )-3-hydroxyhexanoate)s

In vitro cytotoxicity of superheated steam hydrolyzed oligo((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) and characteristics of its blend with poly(L-lactic acid) for biomaterial applications

“…PHBHHxs: P(HB- co -6%-HHx) ( M n 112,000, M w 305,000 Da after purification) and P(HB- co -11%-HHx) ( M n 126,000, M w 352,000 Da after purification) were kindly provided by Kaneka Corporation, Japan. Superheated steam (150 and 190°C) treated PHBHHxs: P(HB- co- 6%-HHx) (SHS 150°C, M n : 31 kDa, M w : 73 kDa); P(HB -co -11%-HHx) (SHS 150°C, M n : 45 kDa, M w : 107 kDa); P(HB- co- 6%-HHx) (SHS 190°C, M n : 2 kDa, M w : 4 kDa); P(HB -co -11%-HHx) (SHS 190°C, M n : 3 kDa, M w : 5 kDa) [ 12 ] were used for in vitro cytotoxicity evaluation. Superheated steam (170°C) treated PHBHHxs: P(HB- co -6%-HHx) (SHS 170°C, M n : 8 kDa, M w : 14 kDa); P(HB- co -11%-HHx) (SHS 170°C, M n : 10 kDa, M w : 21 kDa) [ 12 ] and poly(L-lactic acid) (PLLA) (U'z S-09, M n of 66 kDa, M w of 106 kDa, Toyota Eco Plastic, Japan) [ 16 ] was used for the preparation of PHBHHx/PLLA blend films.…”

“…Superheated steam (150 and 190°C) treated PHBHHxs: P(HB- co- 6%-HHx) (SHS 150°C, M n : 31 kDa, M w : 73 kDa); P(HB -co -11%-HHx) (SHS 150°C, M n : 45 kDa, M w : 107 kDa); P(HB- co- 6%-HHx) (SHS 190°C, M n : 2 kDa, M w : 4 kDa); P(HB -co -11%-HHx) (SHS 190°C, M n : 3 kDa, M w : 5 kDa) [ 12 ] were used for in vitro cytotoxicity evaluation. Superheated steam (170°C) treated PHBHHxs: P(HB- co -6%-HHx) (SHS 170°C, M n : 8 kDa, M w : 14 kDa); P(HB- co -11%-HHx) (SHS 170°C, M n : 10 kDa, M w : 21 kDa) [ 12 ] and poly(L-lactic acid) (PLLA) (U'z S-09, M n of 66 kDa, M w of 106 kDa, Toyota Eco Plastic, Japan) [ 16 ] was used for the preparation of PHBHHx/PLLA blend films. Chemicals and solvents: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) (Bio Basic Canada Inc, Canada), sodium bicarbonate (Sigma-Aldrich, USA), potassium chloride (Fisher Scientific, USA), potassium dihydrogen phosphate, anhydrous (Classic Chemicals, Malaysia), sodium phosphate dibasic anhydrous (Axil Scientific, Singapore), sodium chloride (Classic Chemicals, Malaysia), D(+)-glucose anhydrous (Classic Chemicals, Malaysia), trypLE TM Express (Gibco Life Technologies, USA), Dulbecco’s modified eagle medium (Gibco Life Technologies, USA), fetal bovine serum (HyClone TM , Fisher Scientific, USA), hepes (Sigma-Aldrich, USA), dimethyl sulfoxide (DMSO) (Fisher Scientific, USA) and penicillin-streptomycin solution (Gibco Life Technologies, USA) were used as received.…”

“…In our previous study, superheated steam (SHS) treatment was introduced for minor surface modification of the polymer that simultaneously reduced the molar mass of PHBHHx towards the production of oligoesters [ 12 ]. Previously, in vitro cytotoxicity effect was evaluated for oligo-hydroxyalkanoates (OHAs) with only saturated bonds in their chemical structure, where the lower concentration of OHAs (20 mg L -1 ) was found not to significantly affect cell viability of mouse fibroblast cell line L929 [ 11 ].…”

“…Previously, in vitro cytotoxicity effect was evaluated for oligo-hydroxyalkanoates (OHAs) with only saturated bonds in their chemical structure, where the lower concentration of OHAs (20 mg L -1 ) was found not to significantly affect cell viability of mouse fibroblast cell line L929 [ 11 ]. However, at higher temperatures, SHS treatment produced hydroxyl and alkenyl/unsaturated (crotonoyl and 2-hexenoyl) chain ends [ 12 ], where their in vitro cytotoxicity effect was unknown. Herein the present study proposed to produce biocompatible oligoesters that may serve as a biomaterial, due to the combined advantages of surface properties and the degradation products towards the biocompatibility.…”

Recent Progress in Polyhydroxyalkanoates‐Based Copolymers for Biomedical Applications

“…Although PHBHHx has good properties, it still cannot escape the limitations of the PHA family due to the complicated production process and expensive raw materials. Relative to other members of the PHA family, there are relatively few bacterial species capable of synthesizing PHBHHx . Fukui's team biosynthesized a high‐yield P(3HB‐ co ‐3HHx) by using an artificially modified Ralstonia eutropha and unrelated fructose as a raw material, with 3HHx fragment molar fraction of 22%.…”