Rheological Characterization and Safety Evaluation of Non-Ionic Lamellar Liquid Crystalline Systems Containing Retinyl Palmitate.

Retinyl palmitate (RP) is widely used as a special interest ingredient in dermatological formulations to improve the elasticity of the skin and to reduce wrinkles by stimulating collagen synthesis. Nanotechnology-based drug delivery systems, such as liquid crystalline systems (LCSs), can modulate drug permeation into skin and improve the drug action. The effects of such systems on the skin, however, are not completely known. Possible undesirable effects of these formulations on the skin can be detected and interpreted by histopathology and histomorphometry. The objective of this study was to perform a rheological characterization to evaluate the safety of RP used in a lamellar LCS in vitro and in vivo. LCSs containing polyether functional siloxane as a surfactant, silicon glycol copolymer as an oil phase and water at ratios of 60:10:30 and 40:30:30, with (F1v and F2v, respectively) and without (F1 and F2 respectively) RP, were investigated. The rheological characterization was performed using steady shear rate sweep tests and dynamic frequency sweep tests carried out for up to 30 days for various storage temperature conditions (25 ± 2 °C, 37 ± 2 °C and 5 ± 2 °C). Cytotoxic effects were evaluated using J-774 mouse macrophages as a cellular model system. The in vivo tests were conducted on rabbits that had areas of skin treated as follows for 15 days: C (Control); F1; F1v; F2; and F2v. Histomorphometric and histopathological techniques were used to estimate the thicknesses of the epidermis and stratum corneum and the numbers of fibroblasts and leukocytes in the papillary dermis. Mean values were compared by ANOVA, followed by the Tukey test (p < 0.05). The steady shear rate sweep and dynamic frequency sweep tests confirmed the high viscosity of the LCS and the typical pseudo-plastic characteristic of the lamellar system. The RP-unloaded LCS and the RP-loaded LCS did not produce cytotoxicity, nor did they provoke significant thickening of the epidermis and stratum corneum. The number of leukocytes in the treated areas did not change; however, the number of fibroblasts in the area treated with F1v was higher than in the areas treated with the control and F2. The histological analyses demonstrated that none of the formulations irritated the skin and that formulation F1v significantly increased the number of fibroblasts in the dermis, which could result in an increase in the production of collagen.

Effect of early treatment with transcutaneous electrical diaphragmatic stimulation (TEDS) on pulmonary inflammation induced by bleomycin.

BACKGROUND: Bleomycin (B) is an antineoplastic drug that has pulmonary fibrosis as a side effect. There are few experimental studies about the effects of physical therapy treatment in this case. OBJECTIVE: The objective was to study rat lungs treated with B and precocious intervention by transcutaneous electrical diaphragmatic stimulation (TEDS). METHOD: Wistar rats were divided into 4 groups (n=5): a control group (C); a stimulated group (TEDS); a group treated with a single dose of B (intratracheally, 2.5 mg/kg) (B); and a group treated with B and electric stimulation (B + TEDS). After the B instillation, the electrical stimulation was applied for 7 days, for a duration of 20 minutes. Lung fragments were histologically processed with hematoxylin and eosin (HE) and 8-isoprostane-PGF2α (8-iso-PGF2α). The density of the alveolar area was determined by planimetry, the inflammatory profile was defined by the number of cells, and the level of oxidative stress in the pulmonary tissue was evaluated by 8-iso-PGF2α. For statistical analysis of the data, the Shapiro-Wilk test was used, followed by a one-way ANOVA with the post-hoc Bonferroni test (p ≤ 0.05). RESULTS: The B group exhibited a significant reduction in the area density, and the acute treatment with B + TEDS prevented this reduction. There were increased numbers of fibroblasts, leukocytes, and macrophages in the B group, as well as increased lipid peroxidation, which was observed only in this group. CONCLUSION: B promoted a reduction in the alveolar density area, thereby inducing the inflammatory process and increasing the production of free radicals. These effects were minimized by the application of TEDS at the initial treatment stage.

Effect of early treatment with transcutaneous electrical diaphragmatic stimulation (TEDS) on pulmonary inflammation induced by bleomycin / Efeito do tratamento precoce com estimulacao diafragmatica eletrica transcutanea (EDET) na inflamacao pulmonar provocada pela Bleomicina

BACKGROUND : Bleomycin (B) is an antineoplastic drug that has pulmonary fibrosis as a side effect. There are few experimental studies about the effects of physical therapy treatment in this case. OBJECTIVE: The objective was to study rat lungs treated with B and precocious intervention by transcutaneous electrical diaphragmatic stimulation (TEDS). METHOD : Wistar rats were divided into 4 groups (n=5): a control group (C); a stimulated group (TEDS); a group treated with a single dose of B (intratracheally, 2.5 mg/kg) (B); and a group treated with B and electric stimulation (B + TEDS). After the B instillation, the electrical stimulation was applied for 7 days, for a duration of 20 minutes. Lung fragments were histologically processed with hematoxylin and eosin (HE) and 8-isoprostane-PGF2α (8-iso-PGF2α). The density of the alveolar area was determined by planimetry, the inflammatory profile was defined by the number of cells, and the level of oxidative stress in the pulmonary tissue was evaluated by 8-iso-PGF2α. For statistical analysis of the data, the Shapiro-Wilk test was used, followed by a one-way ANOVA with the post-hoc Bonferroni test (p≤0.05). RESULTS : The B group exhibited a significant reduction in the area density, and the acute treatment with B + TEDS prevented this reduction. There were increased numbers of fibroblasts, leukocytes, and macrophages in the B group, as well as increased lipid peroxidation, which was observed only in this group. CONCLUSION : B promoted a reduction in the alveolar density area, thereby inducing the inflammatory process and increasing the production of free radicals. These effects were minimized by the application of TEDS at the initial treatment stage. .

CONTEXTUALIZAÇÃO: A bleomicina é um antineoplásico que tem como efeito colateral fibrose pulmonar. Há poucos estudos experimentais dos efeitos do tratamento fisioterapêutico nesse quadro. OBJETIVO: Estudar pulmões de ratos tratados com bleomicina e intervenção precoce com estimulação diafragmática elétrica transcutânea (EDET). MÉTODO: Ratos Wistar foram divididos em quatro grupos (n=5): controle; estimulado; tratado com dose única de bleomicina 2,5 mg/Kg, via intratraqueal, e tratado com bleomicina e estimulação elétrica 24 horas após a instilação da bleomicina, durante sete dias, por 20 minutos. Fragmentos de pulmão foram tratados para coloração em hematoxilina e eosina (HE) e 8-isoprostane-PGF2α (8-iso-PGF2 α). A densidade de área alveolar foi obtida por planimetria; o perfil inflamatório, por quantificação do número de células, e os níveis de estresse oxidativo no tecido pulmonar, pela análise do marcador 8-iso-PGF2 α. Utilizou-se teste de normalidade Shapiro-Wilk seguido de ANOVA one-way+Bonferroni (p<0,05). RESULTADOS: O tratamento com bleomicina promoveu redução significativa na densidade de área da parte aérea, e o tratamento agudo de bleomicina associado com a EDET evitou essa redução. Houve aumento no número de fibroblastos, leucócitos e macrófagos e aumento da peroxidação lipídica no grupo tratado com bleomicina, fato não encontrado no grupo bleomicina+EDET. CONCLUSÃO: A bleomicina promoveu diminuição na densidade de área alveolar por induzir processo inflamatório e aumento na produção de radicais livres, efeitos esses minimizados com a intervenção da EDET na fase precoce do tratamento. .

High-voltage electrical stimulation improves nerve regeneration after sciatic crush injury.

BACKGROUND: Peripheral nerve injury causes prolonged functional limitation being a clinical challenge to identify resources that accelerates its recovery. OBJECTIVES: To investigate the effect of high-voltage electrical stimulation (HVES) on the morphometric and functional characteristics of the regenerated nerve after crush injury in rats. METHODS: Twenty Wistar rats were randomly allocated into 4 groups: Control (CON) - without injury and without HVES; Denervated (D) - sciatic nerve crush only; Denervated + HVES - sciatic nerve crush and HVES; SHAM - without injury but HVES. The HVES and SHAM groups were stimulated (100 Hz; minimum voltage of 100 V, 20 µs, 100 µs interpulse interval) for 30 min/day, 5 days/week. The sciatic functional index (SFI) was evaluated before the injury and at the 7th, 14th and 21st postoperatory (PO) days. Neural components and the area density of connective tissue, blood vessels and macrophages were analyzed. RESULTS: Axonal diameter was higher on the HVES than on D group, reaching almost 80% above the control values after 21 days (p<0.05). Fiber diameter and myelin sheath thickness were higher on the HVES than on D group (p<0.05) reaching 96.5% and 100% of the control values, respectively. Functional recovery at the 14th PO day was better on group HVES. The macrophages and connective tissue area density was lower on the HVES group, while blood vessels number did not differ among groups. CONCLUSIONS: The HVES accelerated the functional recovery, potentiated the nerve fibers maturation and decreased macrophages and connective tissue area density, suggesting acceleration of neural repair.

Effect of ultrasound and dexpanthenol on collagen organization in tegumentary lesions.

OBJECTIVE: To analyze the effect of ultrasound (US), dexpanthenol (d-P) and a combination of these treatments (US+d-P) on collagen fiber organization in tegumentary lesions in rats by birefringence analysis. METHODS: Wistar rats (50) were anesthetized (Thionembutal - Sodic = 50 mg/Kg), 1 cm² of dorsal region skin was removed, and the animals were divided into five groups: control (C), gel (G), US (3 MHz, 0.1 W/cm2, 1 minute, continuous), d-P (10%) and US+d-P. After daily treatment for 7 and 14 days, 6 µm thick sections of lesioned areas were stained in picrosirius and measurements of the collagen birefringent area (µm²) were obtained using polarized light microscopy (Zeiss Axiolab-ZEISS- Germany) with histological image analysis software (KS 400 2.0 - Kontrol Eletronics, Munique, Germany). The means were compared by ANOVA followed by the Tukey test (p<0.05). RESULTS: The US+d-P group showed a significantly greater (p ≤ 0.001) birefringent area (1586.43±162.14) than the other experimental groups: C (139.36±35.35), US (317.55±129.9) and d-P (192.41±3657) by the 7th day of treatment, indicating acceleration of the wound healing process. By the 14th day of treatment, the US+d-P, US and d-P groups presented greater birefringence than the control group, but did not differ from each other. CONCLUSION: The combination of treatments (US+d-P) accelerated collagen fiber synthesis and organization in the early stages of cutaneous repair.

High-voltage electrical stimulation improves nerve regeneration after sciatic crush injury / Estimulação elétrica de alta voltagem favorece a regeneração nervosa após compressão do nervo isquiático

BACKGROUND: Peripheral nerve injury causes prolonged functional limitation being a clinical challenge to identify resources that accelerates its recovery. OBJECTIVES: To investigate the effect of high-voltage electrical stimulation (HVES) on the morphometric and functional characteristics of the regenerated nerve after crush injury in rats. METHODS: Twenty Wistar rats were randomly allocated into 4 groups: Control (CON) - without injury and without HVES; Denervated (D) - sciatic nerve crush only; Denervated + HVES - sciatic nerve crush and HVES; SHAM - without injury but HVES. The HVES and SHAM groups were stimulated (100 Hz; minimum voltage of 100 V, 20 μs, 100 μs interpulse interval) for 30 min/day, 5 days/week. The sciatic functional index (SFI) was evaluated before the injury and at the 7th, 14th and 21st postoperatory (PO) days. Neural components and the area density of connective tissue, blood vessels and macrophages were analyzed. RESULTS: Axonal diameter was higher on the HVES than on D group, reaching almost 80 percent above the control values after 21 days (p<0.05). Fiber diameter and myelin sheath thickness were higher on the HVES than on D group (p<0.05) reaching 96.5 percent and 100 percent of the control values, respectively. Functional recovery at the 14th PO day was better on group HVES. The macrophages and connective tissue area density was lower on the HVES group, while blood vessels number did not differ among groups. CONCLUSIONS: The HVES accelerated the functional recovery, potentiated the nerve fibers maturation and decreased macrophages and connective tissue area density, suggesting acceleration of neural repair.

CONTEXTUALIZAÇÃO: Lesões nervosas periféricas provocam limitação funcional prolongada, sendo um desafio para a clínica identificar recursos que acelerem sua recuperação. OBJETIVOS: Investigar a influência da estimulação elétrica de alta voltagem (EEAV) sobre a morfologia e a função do nervo regenerado após esmagamento em ratos. MÉTODOS: Vinte ratos Wistar foram divididos nos grupos: controle (CON) - sem lesão e sem EEAV; desnervado (D) - esmagamento do nervo isquiático; desnervado + EEAV (EEAV) - esmagamento do nervo e EEAV; SHAM - sem lesão, porém submetido à EEAV. Os grupos EEAV e SHAM foram estimulados (100 Hz, tensão mínima de 100 V; 20 μs e 100 μs interpulso) 30 min/dia, 5 dias/semana. O índice funcional do ciático (IFC) foi avaliado antes da lesão, nos 7º, 14º e 21º dias pós-operatório (PO). Componentes neurais, densidade de área de tecido conjuntivo, de vasos sanguíneos e macrófagos foram analisados. RESULTADOS: O diâmetro axonal foi maior no grupo EEAV que no grupo D, atingindo quase 80 por cento dos valores-controle após 21 dias (p<0,05). O diâmetro das fibras e espessura das bainhas de mielina foram maiores no grupo EEAV que no D (p<0,05), alcançando 96,5 por cento e 100 por cento dos valores-controle, respectivamente. A recuperação funcional no 14º dia PO foi melhor no grupo EEAV. A densidade de área de macrófagos e tecido conjuntivo foi menor no grupo EEAV, enquanto o número de vasos sanguíneos não diferiu entre os grupos. CONCLUSÕES: A EEAV acelerou a recuperação funcional, potencializou a maturação das fibras nervosas regeneradas e promoveu diminuição da densidade de área de macrófagos e tecido conjuntivo no nervo, sugerindo aceleração do reparo neural.

Efeito do ultrassom e do dexapantenol na organização das fibras colágenas em lesão tegumentar / Effect of ultrasound and dexpanthenol on collagen organization in tegumentary lesions

OBJETIVO: Analisar o efeito do ultrassom (US), do dexapantenol (d-P) e da associação dos tratamentos (US+d-P) na organização de fibras colágenas na lesão tegumentar em ratos por meio da análise da birrefringência. MÉTODOS: Foram utilizados 50 ratos Wistar, anestesiados com Thionembutal Sódico (50mg/Kg), dos quais foi retirado 1cm² de pele da região dorsal, divididos em cinco grupos: controle (C), gel (G), US (3 MHz, 0,1 W/cm², 1 minuto, modo contínuo), d-P (10 por cento) e US+d-P. Após sete e 14 dias de tratamento diário, foram removidos segmentos dessas áreas e obtidos cortes de 6µm de espessura que, posteriormente, foram corados em Picrosirius. Os cortes foram observados em microscopia de polarização utilizando um software responsável pela medida de birrefringência das fibras colágenas (KS400 2.0 - Kontrol Eletronics). As médias das áreas birrefringentes (µm²) de cada grupo foram submetidas à análise de variância pela ANOVA, seguida do teste de Tukey (p<0,05). RESULTADOS: A média de área birrefringente do grupo US+d-P (1586,43±162,14) foi maior (p<0,001) que a dos grupos experimentais (C: 139,36±35,35, US: 317,55±129,9 e d-P: 192,41±36,57) no 7º dia de tratamento, indicando uma aceleração na síntese e organização das fibras colágenas na região lesionada. No 14º dia de tratamento, os grupos US+d-P (2858,47±510,17), US (1779,94±482,78) e d-P (2546,88±304,45) apresentaram área birrefringente maior que a do grupo C, porém não diferiram entre si. CONCLUSÃO: A associação dos tratamentos (US+d-P) acelerou a síntese e a organização das fibras colágenas apenas no estágio inicial de reparo tegumentar.

OBJECTIVE: To analyze the effect of ultrasound (US), dexpanthenol (d-P) and a combination of these treatments (US+d-P) on collagen fiber organization in tegumentary lesions in rats by birefringence analysis. METHODS: Wistar rats (50) were anesthetized (Thionembutal - Sodic = 50mg/Kg), 1cm² of dorsal region skin was removed, and the animals were divided into five groups: control (C), gel (G), US (3 MHz, 0.1 W/cm2, 1 minute, continuous), d-P (10 percent) and US+d-P. After daily treatment for 7 and 14 days, 6µm thick sections of lesioned areas were stained in picrosirius and measurements of the collagen birefringent area (µm²) were obtained using polarized light microscopy (Zeiss Axiolab-ZEISS- Germany) with histological image analysis software (KS 400 2.0 - Kontrol Eletronics, Munique, Germany). The means were compared by ANOVA followed by the Tukey test (p<0.05). RESULTS: The US+d-P group showed a significantly greater (p<0.001) birefringent area (1586.43±162.14) than the other experimental groups: C (139.36±35.35), US (317.55±129.9) and d-P (192.41±3657) by the 7th day of treatment, indicating acceleration of the wound healing process. By the 14th day of treatment, the US+d-P, US and d-P groups presented greater birefringence than the control group, but did not differ from each other. CONCLUSION: The combination of treatments (US+d-P) accelerated collagen fiber synthesis and organization in the early stages of cutaneous repair.