RESUMO
Nanotechnology has the potential to provide formulations of antitumor agents with increased selectivity towards cancer tissue thereby decreasing systemic toxicity. This in vivo study evaluated the potential of novel nanoformulation based on poly(lactic-co-glycolic acid) (PLGA) to reduce the cardiotoxic potential of doxorubicin (DOX). In vivo toxicity of PLGADOX was compared with clinically approved non-PEGylated, liposomal nanoformulation of DOX (LipoDOX) and conventional DOX form (ConvDOX). The study was performed using Wistar Han rats of both sexes that were treated intravenously for 28 days with 5 doses of tested substances at intervals of 5 days. Histopathological analyses of heart tissues showed the presence of myofiber necrosis, degeneration processes, myocytolysis, and hemorrhage after treatment with ConvDOX, whereas only myofiber degeneration and hemorrhage were present after the treatment with nanoformulations. All DOX formulations caused an increase in the troponin T with the greatest increase caused by convDOX. qPCR analyses revealed an increase in the expression of inflammatory markers IL-6 and IL-8 after ConvDOX and an increase in IL-8 expression after lipoDOX treatments. The mass spectra imaging (MSI) of heart tissue indicates numerous metabolic and lipidomic changes caused by ConvDOX, while less severe cardiac damages were found after treatment with nanoformulations. In the case of LipoDOX, autophagy and apoptosis were still detectable, whereas PLGADOX induced only detectable mitochondrial toxicity. Cardiotoxic effects were frequently sex-related with the greater risk of cardiotoxicity observed mostly in male rats.
Assuntos
Cardiotoxicidade , Doxorrubicina , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos Wistar , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/análogos & derivados , Animais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Ratos , Masculino , Cardiotoxicidade/prevenção & controle , Feminino , Apoptose/efeitos dos fármacos , Nanopartículas/química , Miocárdio/patologia , Miocárdio/metabolismo , Polietilenoglicóis/química , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Coração/efeitos dos fármacos , Lipossomos/químicaRESUMO
The aim of this study was to compare the effects of dexmedetomidine and dexamethasone as adjuvants to preoperative epidural administration of local anesthetic (ropivacaine) in thoracic surgery on the postoperative level of pain, use of analgesics, inflammation, and oxidative stress. The study enrolled 42 patients who underwent elective thoracic surgery in a one-year period at the University Hospital Dubrava (Zagreb, Croatia). Based on a computer-generated randomization list the patients were assigned to the dexmedetomidine (n = 18) or dexamethasone (n = 24) group. Postoperatively, patients of dexmedetomidine group reported lower pain (VAS value 1 h post surgery, 3.4 ± 2.7 vs. 5.4 ± 1.8, dexmedetomidine vs. dexamethasone, p < 0.01) and had lower anal-gesic requirements in comparison with dexamethasone group. Thus, dexmedetomidine in comparison with dexamethasone was more efficient in lowering pain and analgesia requirements 24 h after the surgery. On the contrary, dexamethasone had better anti-inflammatory properties (CRP level 24 h post surgery, 131.9 ± 90.7 vs. 26.0 ± 55.2 mg L-1, dexmedetomidine vs. dexamethasone, p < 0.01). Both dexmedetomidine and dexamethasone exhibited antioxidant effects, however, their antioxidant properties should be further explored. The results of this study improve current knowledge of pain control in thoracic surgery.
