Cytotoxicity and biocompatibility of biomaterials based in polyhydroxybutyrate reinforced with cellulose nanowhiskers determined in human peripheral leukocytes.

Implants of materials that are typically considered inert have been shown to cause early inflammatory complications. In addition, implant wear products may also cause overproduction of proinflammatory cytokines in the long run. Among the cytokines is tumor necrosis factor alpha (TNFα), which not only participates in the inflammatory response but also in the degradation of the bone. Therefore, a lack of production of TNFα by the cells of the immune system in contact with a candidate material for implant design is an indication of the acceptance of the biomaterial, and predicts the inflammatory response responsible for implant intolerance. There is no standard laboratory test to evaluate an individual response of a patient to a possible implant, although the use of peripheral blood mononuclear cells (PBMCs) has been suggested. Here, we evaluated the biocompatibility and cytotoxicity of films made of polyhydroxybutyrate (PHB) reinforced with different concentrations of cellulose nanowhiskers (CNWs) using PBMCs from healthy donors. Cells from healthy donors were cultured in the presence of films of the biomaterial during 24 h and 7 d and the cell viability and proinflammatory cytokines TNFα and IL6 production were measured. We confirmed that PHB, CNWs and the reinforced blends (PHB/CNWs) are safe and lack cytotoxicity in human cells, which make them good candidates for implant materials.