Systemic and local inflammatory response after implantation of biomaterial in critical bone injuries

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.

Perfil de IL-6 e TNF na Formação de Células Espumosas: Um Método Aprimorado Usando a Sonda de Isotiocianato de Fluoresceína (FITC) / Profile of IL-6 and TNF in Foam Cell Formation: An Improved Method Using Fluorescein Isothiocyanate (FITC) Probe

Resumo Fundamento A formação de células espumosas ocorre devido ao aumento em lipoproteína plasmática de baixa densidade (LDL) e desregulação da inflamação, sendo importante para o desenvolvimento da aterosclerose. Objetivo Avaliar o perfil do fator de necrose tumoral alfa (TNF-α) e da interleucina-6 (IL-6) no método de formação da célula espumosa existente, otimizando esse protocolo. Métodos A LDL foi isolada, oxidada e marcada com sonda de isotiocianato de fluoresceína (FITC). As células espumosas foram geradas de célula derivada de monócitos humanos THP-1 e incubadas na ausência (controle) ou presença de FITC-ox-LDL (10, 50, 100, 150 ou 200 μg/mL), por 12, 24, 48 ou 72 horas. A FITC-ox-LDL na célula foi quantificada por microscopia. O ensaio de imunoabsorção enzimática foi avaliado para quantificar a IL-6 e o TNF-α, com um p <0,05 considerado significativo. Resultados Todas as concentrações de FITC-ox-LDL testadas apresentaram fluorescência mais alta em comparação com o controle, demonstrando maior acúmulo de lipoproteínas nas células. Quanto mais alta a concentração de FITC-ox-LDL, maior a produção de TNF-α e IL-6. A produção de IL-6 pelas células espumosas foi detectada até o valor de 150 µg/mL da LDL máxima de estímulo. Concentrações acima de 50 μg/mL de LDL estimularam maior liberação de TNF-α comparado ao controle. Conclusões Nosso modelo contribui para o entendimento da liberação de IL-6 e TNF-α em resposta a várias concentrações de ox-LDL usando o método otimizado para a formação de células espumosas.

Abstract Background The formation of foam cells occurs due to the increase in low-density plasma lipoprotein (LDL) and dysregulation of inflammation, which is important for the development of atherosclerosis. Objective To evaluate the profile of tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6) in the existing foam cell formation method, optimizing this protocol. Methods The LDL was isolated, oxidized, and labeled with a Fluorescein isothiocyanate (FITC) probe. Foam cells were generated from THP-1 human monocyte-derived cells and incubated in the absence (control) or presence of FITC-ox-LDL (10, 50, 100, 150, or 200 μg/mL), for 12, 24, 48, or 72 hours. The accumulated FITC-ox-LDL in the cell was quantified by microscopy. The enzyme-linked immunosorbent assay was evaluated to quantify the IL-6 and TNF-α, with p < 0.05 considered significant. Results All the FITC-ox-LDL concentrations tested showed a higher fluorescence when compared to the control, showing a greater accumulation of lipoprotein in cells. The higher the concentration of FITC-ox-LDL, the greater the production of TNF-α and IL-6. The production of IL-6 by foam cells was detected up to the value of 150 µg/mL of the maximum stimulus for LDL. Concentrations above 50 μg/mL LDL stimulated greater release of TNF-α compared to control. Conclusions Our model contributes to the understanding of the release of IL-6 and TNF-α in response to different concentrations of ox-LDL, using an optimized method for the formation of foam cells.

Comparison of two different biomaterials in the bone regeneration (15, 30 and 60 days) of critical defects in rats

ABSTRACT Purpose To evaluate and compare two types of different scaffolds in critical bone defects in rats. Methods Seventy male Wistar rats (280 ± 20 grams) divided into three groups: control group (CG), untreated animals; biomaterial group 1 (BG1), animals that received the scaffold implanted hydroxyapatite (HA)/poly(lactic-co-glycolic) acid (PLGA); and biomaterial group 2 (BG2), animals that received the scaffolds HA/PLGA/Bleed. The critical bone defect was induced in the medial region of the skull calotte with the aid of an 8-mm-diameter trephine drill. The biomaterial was implanted in the form of 1.5 mm thick scaffolds, and samples were collected after 15, 30 and 60 days. Non-parametric Mann-Whitney test was used, with the significance level of 5% (p ≤ 0.05). Results Histology revealed morphological and structural differences of the neoformed tissue between the experimental groups. Collagen-1 (Col-1) findings are consistent with the histological ones, in which BG2 presented the highest amount of fibers in its tissue matrix in all evaluated periods. In contrast, the results of receptor activator of nuclear factor kappa-Β ligand (Rank-L) immunoexpression were higher in BG2 in the periods of 30 and 60 days, indicating an increase of the degradation of the biomaterial and the remodeling activity of the bone. Conclusions The properties of the HA/PLGA/Bleed scaffold were superior when compared to the scaffold composed only by HA/PLGA.

Efeito de bioterápico na eosinofilia durante a SLMV experimental / Biotherapic effect in eosinophilia during experimental VLMS

O Toxocara canis (Tc) é um parasito pertencente ao filo Nematódeo que possui como hospedeiro definitivo os cães, O homem é hospedeiro paratênico e contamina-se acidentalmente ao ingerir ovos contendo larvas infectantes (L3) do parasito, as quais são liberadas e atravessam a mucosa intestinal, atingem a circulação, Durante este processo migratório, antígenos de excreção e secreção (TES) são liberados provocando intensa reação inflamatória, do tipo Th2, caracterizando a síndrome, denominada Larva Migrans Visceral (SLMV), As principais características desta doença crônica são as eosinofilias sanguínea e tecidual persistentes, Desse modo, torna-se importante a busca por terapias que contribuam com a redução dos quadros inflamatórios com intensa eosinofilia, Assim, o uso deste bioterápico, produzido a partir do extrato antigênico de ovos e larvas de (Tc), e seu efeito no recrutamento de leucócitos totais, células mononucleares e eosinófilos no sangue, para o espaço broncoalveolar e para a cavidade peritoneal de camundongos infectados pelo (Tc) foi investigado, Foram utilizados camundongos fêmeas (Swiss), divididos nos grupos: Controle (C), Infectado (Tc), Imunizado (Im+Tc) e Tratado (Tc+Bio), Os animais Tc, Im+Tc e Tc+Bio receberam 500 ovos/animal por gavagem, Posteriormente, os animais foram eutanasiados no 18º dia da infecção e o número das células nos compartimentos foi determinado, Os resultados obtidos demonstraram que, Im+Tc, assim como nos Tc+Bio tiveram redução significativa dessas células nos compartimentos analisados quando comparados grupo Tc, Assim, sugeriu-se que a bioterapia modulou negativamente o recrutamento de células inflamatórias, principalmente eosinófilos no sangue, pulmão e intestino demonstrando um potencial anti-inflamatório desse bioterápico na SLMV experimental...

The Toxocara canis (Tc) is a parasite that belongs to the nematode phylum and has dogs as definitive host. The men can be accidentally contaminated by ingesting eggs containing infective larvae of the parasite. These larvae, when ingested, pass through the intestinal mucosa, reach the portal circulation and migrate through different tissues of the host. During this process, excretory-secretory antigens (TES) are released causing an intense inflammatory reaction, the Th2 type, characterizing the syndrome, called Visceral Larva migrans (VLMS). The main features of this chronic disease are blood and tissue eosinophilias. Thus, it is important to search for therapies that may contribute to the reduction of inflammatory conditions with intense eosinophilia. In this study, we investigated the use of a biotherapic produced from the antigenic extract from eggs and larvae (Tc) and its effect on the recruitment of total leukocyte, mononuclear cells and eosinophils in blood, bronchoalveolar space and peritoneal cavity of mice infected with (Tc). Female mice (Swiss) were used divided in three groups: control (C), Infected (Tc) Immunized (Im + Tc) and Treaty (Tc + Bio). The animals Tc, Im + Tc and Tc + Bio received 500 eggs / animal by gavage. Subsequently, the animals were euthanized on day 18 after infection and the number of cells in the compartments was determined. Our results showed that, Im + Tc, as in Tc + Bio had reduced these cells in compartments analyzed compared to Tc group. Thus, it was suggested that the biotherapy negatively modulated the recruitment of inflammatory cells, particularly eosinophils in blood, lung and intestine demonstrating an anti-inflammatory potential of the biotherapic in the experimental VLMS...

Toxocara canis and the allergic process

The protective effect of infectious agents against allergic reactions has been thoroughly investigated. Current studies have demonstrated the ability of some helminths to modulate the immune response of infected hosts. The objective of the present study was to investigate the relationship between Toxocara canis infection and the development of an allergic response in mice immunised with ovalbumin (OVA). We determined the total and differential blood and bronchoalveolar lavage fluid cells using BALB/c mice as a model. To this end, the levels of interleukin (IL)-4, IL-5 and IL-10 and anti-OVA-IgE were measured using an ELISA. The inflammatory process in the lungs was observed using histology slides stained with haematoxylin and eosin. The results showed an increase in the total number of leukocytes and eosinophils in the blood of infected and immunised animals at 18 days after infection. We observed a slight lymphocytic inflammatory infiltrate in the portal space in all infected mice. Anti-OVA-IgE levels were detected in smaller proportions in the plasma of immunised and infected mice compared with mice that were only infected. Therefore, we concluded that T. canis potentiates inflammation in the lungs in response to OVA, although anti-OVA-IgE levels suggest a potential reduction of the inflammatory process through this mechanism.