Solid-state properties of pink clay from Jequitinhonha Valley in Brazil for pre-formulation study

Abstract Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) Clay minerals are still widely used in pharmaceutical products for human health and cosmetic purposes. Pre-formulation studies were conducted to identify solid-state properties of pink clay, a sample from Diamantina, Brazil. Among the solid properties to be analyzed, we have selected type identification, iron phases, crystallinity, powder flow characteristics, thermal behavior, and non-isothermal phase transition kinetics. The pink clay is composed of (1:1) clay type and kaolinite as the main component. The Mössbauer spectrum of pink clay shows Fe3+(α-Fe2O3) hematite, Fe2+, and Fe3+ with large Δ/2ξq of about 2.80 and 2.69 mm.s-1 respectively, related to iron silicates, most likely pyroxene, and a superparamagnetic Fe3+. Pink clay exhibits poor flow properties. The thermal behavior indicates a phase-transition between 400 - 600 ºC associated with the dehydroxylation of the pink clay system requiring ~300 kJ mol-1, being constant until the process reaches a conversion of ~50% when the energy is enhanced to ~530 kJ mol-1, concluding the whole dehydroxylation process (α=80%). Solid-state properties and characteristics found for the pink clay must be considered for the proper design of formulations. This type of clay shows unique pharmaceutical properties that can be favorably exploited by the cosmetic industry

Encapsulation of benznidazole in nanostructured lipid carriers and increased trypanocidal activity in a resistant Trypanosoma cruzi strain

Abstract Chagas disease is a neglected parasitic disease caused by Trypanosoma cruzi, whose treatment has remained unsatisfactory for over 50 years, given that it is limited to two drugs. Benznidazole (BZN) is an efficient antichagasic drug used as the first choice, although its poor water-solubility, irregular oral absorption, low efficacy in the chronic phase, and various associated adverse effects are limiting factors for treatment. Incorporating drugs with such characteristics into nanostructured lipid carriers (NLC) is a promising alternative to overcome these limiting obstacles, enhancing drug efficacy and bioavailability while reducing toxicity. Therefore, this study proposed NLC-BZN formulations in different compositions prepared by hot-melt homogenization followed by ultrasound, and the optimized formulation was characterized by FTIR, DRX, DSC, and thermogravimetry. Biological activities included in vitro membrane toxicity (red blood cells), fibroblast cell cytotoxicity, and trypanocidal activity against epimastigotes of the Colombian strain of T. cruzi. The optimized NLC-BZN had a small size (110 nm), negative zeta potential (-18.0 mV), and high encapsulation (1.64% of drug loading), as shown by infrared spectroscopy, X-ray diffraction, and thermal analysis. The NLC-BZN also promoted lower in vitro membrane toxicity (<3% hemolysis), and 50% cytotoxic concentration (CC50) for NLC-BZN in L929 fibroblast cells (110.7 µg/mL) was twice the value as the free BZN (51.3 µg/mL). Our findings showed that the NLC-BZN had higher trypanocidal activity than free BZN against the epimastigotes of the resistant Colombian strain, and this novel NLC-BZN formulation proved to be a promising tool in treating Chagas disease and considered suitable for oral and parenteral administration

Hyaluronic acid-coated nanoemulsions loaded with a hydrophobic ion pair of all-trans retinoic acid for improving the anticancer activity

All-trans retinoic acid (ATRA) has been studied for the treatment of cancer, including leukemia and breast cancer. This work aims to develop nanoemulsions (NE) loaded with a hydrophobic ion pair (HIP) of all-trans retinoic acid (ATRA) and a lipophilic amine, stearylamine (SA), and coated with hyaluronic acid (HA) to enhance anticancer activity and reducing toxicity. Blank NE was prepared by spontaneous emulsification and optimized prior to HIP incorporation. NE-ATRA was electrostatically coated with different concentrations of HA. Incorporation of ATRA-SA led to monodisperse NE with small size (129 ± 2 nm; IP 0.18 ± 0.005) and positive zeta potential (35.7 ± 1.0 mV). After coating with 0.5 mg/mL HA solution, the mean diameter slightly increased to 158 ± 5 nm and zeta potential became negative (-19.7 ± 1.2 mV). As expected, high encapsulation efficiency (near 100%) was obtained, confirmed by polarized light microscopy and infrared analysis. Formulations remained stable over 60 days and release of ATRA from NE was delayed after the hydrophilic HA-coating. HA-coated NE-ATRA was more cytotoxic than free ATRA for MDA-MB-231 and MCF-7 breast cancer cell lines, especially in the CD44 overexpressing cells. Blank coated formulations showed no cytotoxicity. These findings suggest that this easily-made HA-coated NE-ATRA formulation is a promising alternative for parenteral administration, thus improving the breast cancer therapy with this drug.

Clinical-radiographic correlation of the femoral insertion point of the graft in reconstruction of the medial patellofemoral ligament / Correlação clínico-radiográfica do ponto de inserção femoral do enxerto na reconstrução do ligamento patelofemoral medial

To analyze the radiographic positioning of the femoral tunnel and correlate this with the postoperative clinical results among patients undergoing reconstruction of the medial patellofemoral ligament (MPFL) alone. METHOD: This was a retrospective study in which 30 knees of 26 patients with recurrent dislocation of the patella that underwent MPFL reconstruction were evaluated. The femoral insertion point of the graft and the postoperative clinical condition were analyzed and correlated using the Kujala and Lysholm scales. RESULTS: 22 knees presented a femoral tunnel in the anatomical area (group A) and 8 outside of this location (group B). In group A, the mean score on the Kujala scale was 89.68 points and on the Lysholm scale was 92.45 points. In group B, the mean score on the Kujala scale was 84.75 points and on the Lysholm scale was 92 points. The difference between the means was not significant on either of the two scales. CONCLUSION: Correlation with the clinical results did not show any difference in relation to the positioning of the femoral insertion of the graft.

Analisar o posicionamento radiográfico do túnel femoral e correlacioná-lo com os resultados clínicos no pós-operatório em pacientes submetidos à reconstrução isolada do ligamento patelofemoral medial (LPFM). MÉTODO: Estudo retrospectivo, em que foram avaliados 30 joelhos de 26 pacientes com quadro de luxação recidivante da patela submetidos à reconstrução do LPFM, analisados e correlacionados o ponto de inserção femoral do enxerto e o quadro clínico pós-operatório pelas escalas de Kujala e Lysholm. RESULTADOS: Apresentaram túnel femoral na área anatômica (grupo A) 22 joelhos e oito fora desse local (grupo B). No grupo A, a pontuação média pela escala de Kujala foi de 89,68 e pela de Lysholm foi de 92,45. No grupo B, a pontuação média pela escala de Kujala foi de 84,75 e pela de Lysholm foi de 92. A diferença entre as médias não foi significativa nas duas escalas. CONCLUSÃO: Não houve diferença de resultados clínicos correlacionados ao posicionamento da inserção femoral do enxerto.

Lesão da artéria poplítea durante a reconstrução do ligamento cruzado posterior / Popliteal artery injury during posterior cruciate ligament reconstruction

Este trabalho relata uma lesão da artéria poplítea (AP) durante uma reconstrução artroscópica do ligamento cruzado posterior, descreve sua evolução e faz considerações sobre a anatomia dessa artéria e os riscos potenciais dessa técnica cirúrgica. Tem como objetivo alertar a comunidade médica, em especial os cirurgiões de joelho, sobre uma complicação cirúrgica grave e discutir as formas de preveni-la.

This study reports a case of popliteal artery injury during arthroscopic reconstruction of the posterior cruciate ligament. The evolution of the injury is described and comments are made regarding the anatomy of this artery and potential risks of this surgical technique. This study had the aims of alerting the medical community, especially knee surgeons, regarding a severe surgical complication and discussing the ways of preventing it.

Análise bacterioscópica e microbiológica intraoperatória de pacientes submetidos a tratamento cirúrgico de escoliose idiopática do adolescente / Intraoperative bacterioscopical and microbiological analysis in patients undergoing a surgical treatment of adolescent idiopathic scoliosis / Análisis bacterioscópica y microbiológica intraoperatoria de pacientes sometidos al tratamiento quirúrgico de la escoliosis idiopática del adolescente

OBJETIVO: Avaliar a presença e o crescimento microbiológico no sítio operatório em pacientes submetidos a tratamento cirúrgico de escoliose idiopática do adolescente na primeira, segunda e terceira hora de cirurgia. Casuística e MÉTODO: Estudo prospectivo, de caráter descritivo e comparativo, sendo avaliados 34 pacientes portadores de escoliose idiopática do adolescente com indicação cirúrgica, analisando a contaminação no sítio cirúrgico através da bacterioscopia e cultura óssea na primeira, segunda e terceira hora de cirurgia. RESULTADOS: Houve bacterioscopia positiva crescente entre a primeira e a segunda hora de cirurgia. A cultura confirma a colonização da ferida operatória, crescente entre as horas analisadas. CONCLUSÕES: O tempo cirúrgico prolongado está diretamente relacionado ao maior crescimento microbiológico no sítio cirúrgico de pacientes submetidos à correção de escoliose vertebral.

OBJECTIVE: To evaluate the presence and microbiological growth in the operative site in patients undergoing surgical treatment of idiopathic scoliosis in the spine of first, second and third hours of surgery. METHODS: Prospective, descriptive and comparative study that evaluated 34 patients with adolescent idiopathic scoliosis with surgical indication, analyzing contamination at the surgical site through Gram staining and bone culture in the first, second and third hour of surgery. RESULTS: There were positive bacteroscopical growing between the first and the second hour of surgery. The culture confirms the colonization of the wound, increasing between the hours analyzed. CONCLUSIONS: The prolonged surgical time is directly related to higher microbial growth in the surgical site in patients undergoing spinal scoliosis correction.

OBJETIVO: Evaluar la presencia y el crecimiento microbiológico, en el área operatoria, en pacientes sometidos a tratamiento quirúrgico de escoliosis idiopática del adolescente en la primera, segunda y tercera hora de la intervención quirúrgica. Casuística y MÉTODO: Estudio prospectivo, de carácter descriptivo y comparativo, habiendo sido evaluados 34 pacientes portadores de escoliosis idiopática del adolescente con indicación quirúrgica, siendo analizada la contaminación en el área de la operación quirúrgica mediante la bacterioscopia y el cultivo óseo en la primera, segunda y tercera hora de la intervención quirúrgica. RESULTADOS: Hubo bacterioscopia positiva creciente entre la primera y la segunda hora de la operación quirúrgica. El cultivo confirmó la colonización de la herida operatoria, siendo creciente entre las horas analizadas. CONCLUSIONES: El tiempo prolongado de la operación quirúrgica está relacionado directamente con el aumento del crecimiento microbiológico en el área quirúrgica de pacientes sometidos a corrección de la escoliosis vertebral.