Effects of Sterilization and Hydrolytic Degradation on the Structure, Morphology and Compressive Strength of Polylactide-Hydroxyapatite Composites

Abstract

Composites based on polylactide (PLA) and hydroxyapatite (HA) were prepared using a thermally induced phase separation method. In the experimental design, the PLA with low weight-average molar mass (Mw) and high Mw were tested with the inclusion of HA synthesized as whiskers or hexagonal rods. In addition, the structure of HA whiskers was doped with Zn, whereas hexagonal rods were mixed with Sr salt. The composites were sterilized and then incubated in phosphate-buffered saline for 12 weeks at 37 °C, followed by characterization of pore size distribution, molecular properties, density and mechanical strength. Results showed a substantial reduction of PLA Mw for both polymers due to the preparation of composites, their sterilization and incubation. The distribution of pore size effectively increased after the degradation process, whereas the sterilization, furthermore, had an impact on pore size distribution depending on HA added. The inclusion of HA reduced to some extent the degradation of PLA quantitatively in the weight loss in vitro compared to the control without HA. All produced materials showed no cytotoxicity when validated against L929 mouse skin fibroblasts and hFOB 1.19 human osteoblasts. The lack of cytotoxicity was accompanied by the immunocompatibility with human monocytic cells that were able to detect pyrogenic contaminants.

Sea Cucumber‐Inspired Aerogel for Ultrafast Hemostasis of Open Fracture

“…Rapid degradation of the filling material is unfavorable to bone growth and long‐term healing, implying the influence of the material degradation rate on bone regeneration. It is speculated that GCG‐4H may slow down the degradation of materials due to the doping of CS‐GA or nHA, [ 33 ] which is of great help to bone regeneration, at least it will not degrade completely before the defect is completely healed, which also indicates the advantage of GCG‐4H in bone defect healing. [ 34 ] We compared the degradation characteristics of GCG‐4H and GCG based on previous research to verify the effect of inorganic materials (Figure S8, Supporting Information).…”

Covalent segmented polymer networks composed of poly(2-isopropenyl-2-oxazoline) and selected aliphatic polyesters: designing biocompatible amphiphilic materials containing degradable blocks

“…According to ISO 10993-5:2009, cell viability/metabolic activity below 70% (cut off) shows the cytotoxic effect of tested compounds towards eukaryotic cells. 63 Tested hydrogels: PLA 3000 - l -PiPOx-4 and PCL 3000 - l -PiPOx-4 should be recognized as cytobiocompatible (Fig. 9) and may be further tested in more complex in vitro experiments.…”