Development of Thermo- and pH-Sensitive Liposomal Magnetic Carriers for New Potential Antitumor Thienopyridine Derivatives.

The development of stimuli-sensitive drug delivery systems is a very attractive area of current research in cancer therapy. The deep knowledge on the microenvironment of tumors has supported the progress of nanosystems' ability for controlled and local fusion as well as drug release. Temperature and pH are two of the most promising triggers in the development of sensitive formulations to improve the efficacy of anticancer agents. Herein, magnetic liposomes with fusogenic sensitivity to pH and temperature were developed aiming at dual cancer therapy (by chemotherapy and magnetic hyperthermia). Magnetic nanoparticles of mixed calcium/manganese ferrite were synthesized by co-precipitation with citrate and by sol-gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy in transmission mode (STEM), and superconducting quantum interference device (SQUID). The citrate-stabilized nanoparticles showed a small-sized population (around 8 nm, determined by XRD) and suitable magnetic properties, with a low coercivity and high saturation magnetization (~54 emu/g). The nanoparticles were incorporated into liposomes of dipalmitoylphosphatidylcholine/cholesteryl hemisuccinate (DPPC:CHEMS) and of the same components with a PEGylated lipid (DPPC:CHEMS:DSPE-PEG), resulting in magnetoliposomes with sizes around 100 nm. Dynamic light scattering (DLS) and electrophoretic light scattering (ELS) measurements were performed to investigate the pH-sensitivity of the magnetoliposomes' fusogenic ability. Two new antitumor thienopyridine derivatives were efficiently encapsulated in the magnetic liposomes and the drug delivery capability of the loaded nanosystems was evaluated, under different pH and temperature conditions.

Magnetoliposomes Incorporated in Peptide-Based Hydrogels: Towards Development of Magnetolipogels.

A major problem with magnetogels is the encapsulation of hydrophobic drugs. Magnetoliposomes not only provide these domains but also improve drug stability and avert the aggregation of the magnetic nanoparticles. In this work, two magnetoliposome architectures, solid and aqueous, were combined with supramolecular peptide-based hydrogels, which are of biomedical interest owing to their biocompatibility, easy tunability, and wide array of applications. This proof-of-concept was carried out through combination of magnetoliposomes (loaded with the model drug curcumin and the lipid probe Nile Red) with the hydrogels prior to pH triggered gelation, and fluorescence spectroscopy was used to assess the dynamics of the encapsulated molecules. These systems allow for the encapsulation of a wider array of drugs. Further, the local environment of the encapsulated molecules after gelation is unaffected by the used magnetoliposome architecture. This system design is promising for future developments on drug delivery as it provides a means to independently modify the components and adapt and optimize the design according to the required conditions.

Progesterone and estradiol receptors and Ki-67 in the superficial and deep infiltrating endometriosis / Receptores de progesterona e estradiol e Ki-67 no estroma e no epitélio de endometriose superficial e profunda

ABSTRACT Introduction: Endometriosis is a hormone-dependent disease characterized by ectopic presence of endometrial tissue responsive to ovarian steroids. Estrogen and progesterone are the main regulators of endometrial tissue, and the expression of receptors of these hormones in the ectopic tissue seems to be related to the pathophysiology of the disease. Ki-67 is a marker of tissue proliferation and an important marker of epithelial kinetics. Endometriosis can be classified as superficial, in the peritoneum, and deep, when it extends into ligaments and other organs. Objective: Our objective was to analyze the expression of estrogen and progesterone receptors and Ki-67, through immunohistochemistry, in different sites of endometriosis tissues (superficial peritoneal/ovarian endometriosis and deep infiltrating endometriosis). Casuistic and methods: We studied nine patients; five with superficial and four with deep endometriosis. Statistical correlation was performed with the Shapiro-Wilk test (significance level of 5%) and linear correlation analysis using Spearman's non-parametric test (significance of 1%). There was a correlation of Spearman between the estrogen receptor variable and Ki-67 in patients with superficial endometriosis. There was also a correlation between the variables estrogen receptor and progesterone receptor in patients with deep endometriosis. Results: Contrary to what was found for superficial endometriosis, there is linear increase of the variables, with a strong and positive correlation coefficient. This demonstrates that the variation of estrogen receptors can be explained in 99.1% by the same variation of progesterone receptors in deep endometriosis. Conclusion: It is possible to infer that other factors are involved in the response to hormonal variations for superficial and deep endometriosis.

RESUMEN Introducción: Endometriosis es una enfermedad dependiente de hormonas que se caracteriza por la presencia ectópica de tejido endometrial sensible a los esteroides del ovario. El estrógeno y la progesterona son los principales reguladores del tejido endometrial, y la expresión de receptores de esas hormonas en el tejido ectópico parece tener conexión con la fisiopatología de la enfermedad. El Ki-67 es un marcador de proliferación tisular y de la cinética epitelial. La endometriosis puede ser clasificada en superficial y profunda, alcanzando ligamentos y otros órganos. Objetivo: El objetivo de este estudio fue analizar la expresión de los receptores de estrógeno y progesterona y Ki-67, mediante inmunohistoquímica en endometriosis superficial peritoneal/ ovárica y endometriosis infiltrativa profunda. Casuística y métodos: Estudiamos nueve casos: cinco de endometriosis superficial y cuatro de endometriosis profunda. La correlación estadística fue realizada con el test de Shapiro-Wilk (nivel de significación del 5%), y el análisis de correlación linear, por la prueba no paramétrica de Spearman (nivel de significación del 1%). Hubo correlación de Spearman entre la variable receptor de estrógeno (RE) y Ki-67 en pacientes con endometriosis superficial, y entre las variables RE y receptor de progesterona (RP) en pacientes con endometriosis profunda. Resultados: Al contrario de lo que se ha encontrado para endometriosis superficial, hay aumento lineal de las variables, con coeficiente de correlación fuerte e positivo. Eso demuestra que la variación de los receptores para estrógeno puede ser explicada en el 99,1% por la misma variación de los RP en la endometriosis profunda. Conclusión: Es posible deducir que otros factores estén involucrados en las diferentes respuestas hormonales para endometriosis superficial y profunda.

RESUMO Introdução: Endometriose é doença hormônio-dependente caracterizada pela presença ectópica de tecido endometrial responsivo aos esteroides ovarianos. O estrogênio e a progesterona são os principais reguladores do tecido endometrial, e a expressão de receptores desses hormônios no tecido ectópico parece ter relação com a fisiopatologia da doença. O Ki-67 é um marcador de proliferação tecidual e importante sinalizador da cinética epitelial. A endometriose pode ser classificada em superficial e profunda, atingindo ligamentos e outros órgãos. Objetivo: O objetivo deste estudo foi analisar a expressão dos receptores de estrógeno e progesterona e Ki-67, por meio de imuno-histoquímica em endometriose superficial peritoneal/ovariana e endometriose infiltrativa profunda. Casuística e métodos: Estudamos nove casos, cinco de endometriose superficial e quatro de endometriose profunda. A correlação estatística foi efetuada com os testes de Shapiro-Wilk (nível de significância 5%) e a análise de correlação linear, pelo teste não paramétrico de Spearman (1% de significância). Houve correlação de Spearman entre a variável receptor de estrogênio (RE) e Ki-67 em pacientes com endometriose superficial e entre as variáveis RE e receptor de progesterona (RP) em pacientes com endometriose profunda. Resultados: Ao contrário do que foi encontrado para endometriose superficial, há o aumento linear das variáveis, com coeficiente de correlação forte e positivo. Isso demonstra que a variação dos receptores para estrogênio pode ser explicada em 99,1% pela mesma variação dos RP na endometriose profunda. Conclusão: É possível inferir que estejam envolvidos outros fatores nas diferentes respostas hormonais para endometriose superficial e profunda.