Effect of Polyhydroxyalkanoate (PHA) Concentration on Polymeric Scaffolds Based on Blends of Poly-L-Lactic Acid (PLLA) and PHA Prepared via Thermally Induced Phase Separation (TIPS)

Abstract

Hybrid porous scaffolds composed of both natural and synthetic biopolymers have demonstrated significant improvements in the tissue engineering field. This study investigates for the first time the fabrication route and characterization of poly-L-lactic acid scaffolds blended with polyhydroxyalkanoate up to 30 wt%. The hybrid scaffolds were prepared by a thermally induced phase separation method starting from ternary solutions. The microstructure of the hybrid porous structures was analyzed by scanning electron microscopy and related to the blend composition. The porosity and the wettability of the scaffolds were evaluated through gravimetric and water contact angle measurements, respectively. The scaffolds were also characterized in terms of the surface chemical properties via Fourier transform infrared spectroscopy in attenuated total reflectance. The mechanical properties were analyzed through tensile tests, while the crystallinity of the PLLA/PHA scaffolds was investigated by differential scanning calorimetry and X-ray diffraction.

Polyhydroxyalkanoates Composites and Blends: Improved Properties and New Applications

“…These reports have further broadened current and perspective applications of PHAbased materials (Table 1). SEM studies demonstrated significant variability on the nanolevel 3D structures of the ES mixtures P(3HB): mcl-PHA [62] and foams PLLA/PHA [63]. SEM studies demonstrated significant variability on the nanolevel 3D structures of the ES mixtures P(3HB): mcl-PHA [62] and foams PLLA/PHA [63].…”

“…These reports have further broadened current and perspective applications of PHAbased materials (Table 1). SEM studies demonstrated significant variability on the nanolevel 3D structures of the ES mixtures P(3HB): mcl-PHA [62] and foams PLLA/PHA [63]. Studies have proven that combining different types of PHAs (see Figure 4) in right proportions with other material significantly enhances wide variety of their properties [60].…”

“…SEM studies demonstrated significant variability on the nanolevel 3D structures of the ES mixtures P(3HB): mcl-PHA [62] and foams PLLA/PHA [63]. SEM studies demonstrated significant variability on the nanolevel 3D structures of the ES mixtures P(3HB): mcl-PHA [62] and foams PLLA/PHA [63]. Experiments have been carried out to observe the bio-nanocomposites based on PHAs and have proven to have positive effects on properties such as the size of the surface area of its active sites.…”

Improvement of Osteogenic Differentiation of Mouse Pre-Osteoblastic MC3T3-E1 Cells on Core–Shell Polylactic Acid/Chitosan Electrospun Scaffolds for Bone Defect Repair

“…For the sake of brevity, FTIR-ATR spectra of P-PLA/Chi samples are not shown, as no significant differences were found in comparison with PLA/Chi results. According to the literature, the ATR-FTIR spectrum of PLA showed various absorption bands usually attributed to this polyester, such as the carbonyl stretch at 1747 cm −1 ; the C–O stretch at 1180 cm −1 , 1129 cm −1 and 1083 cm −1 ; and the OH bend at 1044 cm −1 [ 41 ]. The FTIR-ATR spectrum of neat chitosan powder reveals main absorption bands at 3352 cm (stretching vibration of O–H group) [ 42 ], 3290 cm −1 (stretching vibration of N–H) [ 42 ], 1645 cm −1 (stretching vibration of the carbonyl group (C=O) in amide I) [ 43 , 44 ], and 1039 cm −1 (stretch vibrations of C–O) [ 45 ].…”