35 research outputs found

    Desenvolvimento de formulações nanotecnológicas contendo imiquimode para o tratamento do câncer cervical

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    Esta tese se fundamenta na necessidade de novos tratamentos para o câncer do colo de útero visando o aumento da adesão dos pacientes aos tratamentos, assim como à qualidade de vida dos mesmos. Nesse sentido, formulações nanotecnológicas foram desenvolvidas com o objetivo de carrear o fármaco imiquimode para um local específico – a mucosa vaginal – esperando gerar melhores desempenhos nesse tratamento quando comparados com a formulação comercial. Três nanoestruturas com morfologias distintas foram propostas visando potencializar o efeito do fármaco em células de câncer cervical (SiHa). As formulações desenvolvidas compreenderam: nanoemulsões (NEimiq), nanocápsulas poliméricas (NCimiq) e nanocápsulas poliméricas revestidas com quitosana (NCimiq-chit). Observou-se que nanocápsulas poliméricas produzidas com poli(ε-caprolactona) apresentaram efeito mais pronunciado frente às células SiHa. Para tanto, essas formulações (NCimiq e NCimiq-chit) foram incorporadas em hidrogéis de quitosana e de hidroxietilcelulose a fim de possibilitar uma melhor futura aplicação para o paciente. Estudos envolvendo mucosa vaginal suína demonstraram que ambas as formulações são mucoadesivas e permeiam a mucosa vaginal. Porém, a formulação produzida com hidrogel de quitosana (NCimiq) apresentou maior desempenho. Esta foi a formulação escolhida para dar continuidade aos estudos deste trabalho, sendo objeto de estudo posterior em cultura de células SiHa a fim de elucidar o mecanismo de ação da mesma. Esses estudos demonstraram que há uma ocorrência de processos combinados de diminuição da viabilidade celular de maneira tempo-dependente e que mecanismos como apoptose, autofagia e parada de ciclo celular estão presentes. Essa formulação (NCimiq) apresentou porcentagens de morte celular significativas, mesmo utilizando baixas concentrações do fármaco. Portanto, os achados desta tese constataram que nanoestruturas modulam efetivamente a interação do fármaco com as células.This thesis deals with the need of new treatments for cervical cancer in order to increase the adherence of patients to the treatment as well as to improve their quality of life. In this sense, nanotechnological formulations were developed to carry imiquimod to a specific site – the vaginal mucosa – expecting to obtain better performance than the commercial drug in the cervical cancer treatment. Three nanostructures with different morphologies were proposed to potentilize the drug effect on cervical cancer cells (SiHa). The developed formulations are: nanoemulsions (NEimiq), polymeric nanocapsules (NCimiq) and polymeric nanocapsules coated with chitosan (NCimiq-chit). It was observed that polymeric nanocapsules produced with poly(ε-caprolactone) presented a stronger effect against SiHa cells. Therefore, formulations NCimiq and NCimiq-chit were incorporated into hydrogels of chitosan and hydroxyethylcellulose to enable a better future application on patients. The studies of this thesis involving porcine vaginal mucosa demonstrated that both formulations are mucoadhesive and that they provided a good drug permeation. However, the formulation produced with chitosan hydrogel (NCimiq) showed a better performance. This formulation was therefore chosen to follow the next steps of this work, conducted in SiHa cell culture to elucidate its action mechanism. This study demonstrated that there is an occurrence of combined processes of decreasing cell viability in a time-dependent type. The study also showed that mechanisms such as apoptosis, autophagy and cell cycle arrest are simultaneously present. The formulation NCimiq presented a significantly percentage of cellular death, even when low concentrations of the drug were used. Consequently, the findings of this thesis indicate that nanostructures effectively modulate the interaction of the drug with the cancer cells

    Novel treatment approaches to combat trichomoniasis, a neglected and sexually transmitted infection caused by trichomonas vaginalis : translational perspectives

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    The multistep translational science behind new drugs comprehends the entire process through laboratory, clinical, and community observations turned into health interventions. The development of new drug options from discovering targets and leading compounds in basic research for implementing therapeutic guidelines contributes to the emergence of health policies essential for infection control. This review updates the translational research in the scenario of the most common non-viral sexually transmitted infection (STI), trichomoniasis. Paradoxically to its high occurrence, it is considered neglected since notification is not mandatory. It turns into a stable disease with health complications, and receives little emphasis from public health programs to control STI. Although related to curable STIs, the current drugs, metronidazole and tinidazole, present therapeutic failures. The need for new options to treat trichomoniasis is established by basic research studies and patents revealing novel synthetic compounds and natural products presenting anti-Trichomonas vaginalis activities, mainly based on in vitro findings. Clinical trials are still focused on new routes of administration for conventional drugs. In addition, nanotechnology approaches are in their infancy, shedding light on potential possibilities for creating more effective, targeted, and safe delivery systems. Overall, the novel proposed approaches need, in addition to pharmaceutical development and efficacy assessments, to ensure that the quality requirements for their use as medicines are met. It is essential to overcome these issues to cross the “Death Valley” of drug discovery and to advance in the translational science criteria in the trichomoniasis drug development field

    Chemoprevention in oral leukoplakia: challenges and current landscape

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    Oral potentially malignant disorders have the potential to transform into oral cancer. Oral leukoplakia is a prevalent OPMD with a 9.8% malignant transformation rate. The standard management for OL involves surgical excision, but its efficacy in preventing clinical recurrence and malignant transformation is limited. Therefore, alternative strategies such as chemoprevention modalities have emerged as a promising approach to inhibit the carcinogenesis process. The aim of this review was to identify human studies that investigated the effectiveness of chemopreventive agents in preventing the progression of oral leukoplakia and to provide guidance for future research. Several systemic and topical agents have been evaluated for their potential chemopreventive effects in oral leukoplakia. Systemic agents that have been investigated include vitamin A, lycopene, celecoxib, green tea extract, ZengShengPing, Bowman Birk inhibitor, beta-carotene, curcumin, erlotinib, and metformin. In addition, topical agents tested include bleomycin, isotretinoin, ONYX-015 mouthwash, ketorolac, and dried black raspberry. Despite numerous agents that have already been tested, evidence supporting their effectiveness is limited. To improve the search for an ideal chemopreventive agent for oral leukoplakia, we propose several strategies that can be implemented. Oral leukoplakia chemoprevention presents a promising opportunity for decreasing the incidence of oral cancer. Identifying new chemopreventive agents and biomarkers for predicting treatment response should be a focus of future research

    Otoliths-composed gelatin/sodium alginate scaffolds for bone regeneration

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    Evidence that otoliths, mineral-rich limestone concrescences present in the inner ear of bone fishes, can accelerate bone formation in vivo has been previously reported. The goal of this work was the development, characterization, and evaluation of the cytocompatibility of otoliths-incorporated sodium alginate and gelatin scaffolds. Cynoscion acoupaderived otoliths were characterized by X-ray fluorescence spectrometry (FRX), particle size, free lime, and weight loss by calcination. Furthermore, otoliths were incorporated into sodium alginate (ALG/OTL-s) or gelatin (GEL/OTL-s) scaffolds, previously developed by freeze-drying. Then, the scaffolds were characterized by thermogravimetric analysis (TGA/DTG), differential scanning calorimetry (DSC), infrared spectroscopy with Fourier transform (FTIR), swelling tests, and scanning electron microscopy (SEM). Cytotoxicity assays were run against J774.G8 macrophages and MC3T3-E1 osteoblasts. Data obtained from TGA/DTG, DSC, and FTIR analyses confirmed the interaction between otoliths and the polymeric scaffolds. SEM showed the homogeneous porous 3D structure rich in otolith micro-fragments in both scaffolds. Swelling of the GEL/OTL-s (63.54±3.0%) was greater than of ALG/OTL-s (13.36±9.9%) (p0.05) and significantly higher than that treated with Triton-X (p0.05). However, by 48 h, only ALG/OTL-s showed growth similar to control (p>0.05), whereas GEL/OTL showed a significantly lower growth index (p<0.05). In conclusion, the physicochemical profiles suggest proper interaction between the otoliths and the two developed polymeric 3D scaffolds. Moreover, both materials showed cytocompatibility with J774.G8 macrophages but the growth of MC3T3-E1 osteoblasts was higher when exposed to ALG/OTL-s. These data suggest that sodium alginate/otoliths scaffolds are potential biomaterials to be used in bone regeneration applications.We would like to thank the National Council for Scientific and Technological Development (CNPq) and the Foundation for Research and Technological Innovation Support of the State of Sergipe for the financial support in this study. EMBS acknowledges the sponsorship of the projects M-ERA-NET-0004/2015-PAIRED and UIDB/04469/2020 (strategic fund), received support from the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and was co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
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