Titanium dioxide nanoparticles (TiO₂ NPs) are the most produced nanomaterials. TiO₂ NPs are used as a drug carrier and molecular imaging vehicle in the cardiovascular system. We aimed to study TiO₂ NPs effects on the ventricular myocardium and evaluate the ameliorative effects of β-carotene (βC). Forty adult albino rats were divided into four groups: negative control group (Ι) received a distilled water. Treated group (II): received 20 mg/kg/day TiO₂NPs intraperitoneally. Protected group (III): received 10 mg/kg/day βC orally together with TiO₂ NPs in a dose of 20 mg/kg/day intraperitoneally. Positive control group (IV) was given βC orally in a dose of 10 mg/kg/day for 14 days. Sections were stained with hematoxylin & eosin, bromphenol blue (BPB), and periodic acid Schiff (PAS). Anti-desmin & anti-CD45 immunohistochemical staining and electron microscopic examination were performed. Group (II) revealed fragmented myofibrils and inflammatory infiltrations. In group (III), normal cardiomyocytes with less inflammatory infiltrations. The optical density of PAS and BPB staining and anti-desmin showed a very highly significant decrease in the group (II) versus the control groups (P < 0.001). A highly significant increase in the optical density of group (III) versus group (II) (P < 0.01). Also, the area percentage mean values of collagen fibers and anti-CD45 in the group (II) showed a very highly significant increase versus the control groups (P < 0.001). Group (III) revealed a very highly significant decrease in the area percentage versus group (II) (P < 0.001). In conclusion: TiO₂ NPs adversely affected the histological structure of the adult rat ventricular myocardium in acute exposure (14 days) and the damage was less with βC.

二氧化钛纳米颗粒（TiO ₂ NPs）是生产最多的纳米材料。TiO ₂ NP被用作心血管系统中的药物载体和分子成像载体。我们旨在研究TiO ₂ NPs对心室心肌的作用，并评估β-胡萝卜素（βC）的改善作用。将四十只成年白化病大鼠分为四组：阴性对照组（I）接受蒸馏水。治疗组（II）：腹膜内接受20 mg / kg / day的TiO ₂ NP。保护组（III）：口服口服10 mg / kg /天的βC和TiO ₂腹膜内剂量为20 mg / kg /天的NP。阳性对照组（IV）口服βC，剂量为10 mg / kg / day，持续14天。将切片用苏木精和曙红，溴酚蓝（BPB）和高碘酸席夫（PAS）染色。进行抗结蛋白和抗CD45免疫组化染色以及电子显微镜检查。（II）组显示肌原纤维断裂和炎性浸润。在第（III）组中，正常心肌细胞的炎症浸润较少。与对照组相比，组（II）中PAS和BPB染色的光密度和抗结蛋白显示出非常非常显着的降低（P <0.001）。组（III）相对于组（II）的光密度显着增加（P <0.01）。也，组（II）中胶原纤维和抗CD45的面积百分比平均值显示与对照组相比有非常显着的增加（P <0.001）。（III）组显示面积百分比相对于（II）组有非常显着的降低（P <0.001）。结论：二氧化钛₂ NPs在急性暴露（14天）中对成年大鼠心室心肌的组织学结构产生不利影响，βC对损伤的影响较小。