ABSTRACT
Purpose:
To evaluate inflammatory response in critical bone injuries after implantation of the biomaterial composed of hydroxyapatite (HA)/poly (lactic-coglycolic acid) (PLGA)/BLEED.
Methods:
Forty-eight male Wistar rats (280 ± 20 grams) were divided into two groups: control group (CG), in which the animals do not receive any type of treatment; and biomaterial group (BG), in which the animals received the HA/PLGA/BLEED scaffold. Critical bone injury was induced in the medial region of the skull calotte with the aid of a trephine drill 8 mm in diameter. The biomaterial was implanted in the form of 1.5-mm thick scaffolds. Serum and calotte were collected at one, three and seven days.
Results:
Biomaterial had a significant effect on the morphological structure of the bone, accelerating osteoblast activation within three days, without causing exacerbated systemic inflammation. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that BG induced upregulation of osteogenic genes such as runt-related transcription factor 2, and stimulated genes of inflammatory pathways such as tumor necrosis factor-α, on the first day without overexpressing genes related to bone matrix degradation, such as tissue inhibitor of metalloproteinases-1 and matrix metalloproteinase-9.
Conclusions:
The HA/PLGA/BLEED® association can be used as a bone graft to aid bone repair, as it is capable of modulating expression of important genes at this stage of the repair process.
Key words
Biocompatible Materials; Skull; Bone Regeneration; Immunity
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CG: control group; BG: biomaterial group HA: hydroxyapatite; PLGA: poly (lactic-coglycolic acid). Source: elaborated by the authors.
Source: Elaborated by the authors.
IL-6: interleukin 6; TNF-α: tumor necrosis factor-α; CG: control group; BG: composite biomaterial group; *BG versus CG on the first day; αBG versus CG on the seventh day. Source: elaborated by the authors.
IL-4: interleukin 4; IL-10: interleukin 10; CG: control group; BG: composite biomaterial (HA/PLGA/BLEED); *BG versus CG on the first day; αBG versus CG on the seventh day. Source: elaborated by the authors.
TIMP-1: tissue inhibitor of metalloproteinases-1; MMP-9: matrix metalloproteinase-9; TNF-α: tumor necrosis factor-α; Runx2: runt-related transcription factor-2; CG: control group; BG: composite biomaterial (HA/PLGA/BLEED); *BG versus CG on the first day; αBG versus CG on the seventh day; βBG on the seventh day versus BG on the first day. Source: elaborated by the authors.
TIMP-1: tissue inhibitor of metalloproteinases-1; TNF-α: tumor necrosis factor-α; Runx2: runt-related transcription factor-2; MMP-9: matrix metalloproteinase-9. Source: elaborated by the authors.