Charakterisierung eines neuartigen Knochenersatzmaterials auf PLGA-Basis hinsichtlich Immunreaktivität, Zytokompatibilität und physikalischen Eigenschaften

Introduction: Bone graft substitutes are becoming increasingly important in regenerative medicine. Polylactide-co-glycolide (PLGA) is already widely used as an established synthetic biomaterial in medical care, often in the form of microparticles or placeholders loaded with antibiotics or immunoactive cells for topical antibiotic therapy and release of regenerative cells in a defect zone. The aim of this study was to characterise a new form of PLGA for its physical properties, immunological signature and ytocompatibility. This material should allow the use of PLGA in the form of a porous membrane to cover large bone defects. Material and methods: The PLGA mixture was prepared in the form of scaffolds and membranes. A biomechanical analysis of the material for fracture strength, flexural rigidity and its diffusion capacity was performed. The scaffolds were seeded with bone marrow stem cells (BMC and MSC). MTT assay was used to determine the lifespan and viability of the cells on the scaffold surface. The cells were examined for osteogenic differentiation by PCR analysis. A whole blood stimulation assay followed by comprehensive evaluation of the secretome using a Proteome Profiler assay was performed to record the immunological signature. Results: The material showed low mechanical stability. The PLGA membrane was permeable for proteins up to 11.4 kDa. A steady degeneration of the material in an aqueous environment was observed. Secretome analysis of the whole blood stimulation assay revealed an immunological signature characteristic of the PLGA membrane with activation of proinflammatory factors. Cell survival on the scaffold surface decreased consistently during the acquisition period, while cell viability on the well bottom increased. No significant osteogenic differentiation of stem cells was detected. Discussion: The rapid degeneration of the material in an aqueous environment negatively affected both membrane stability and cell adhesion to the scaffolds. The material neither had a toxic effect on the cells ...