JUSTINE PAULA RAMOS DE OLIVEIRA
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
Artigo IPEN-doc 29052 Mucoadhesive polymers and their applications in drug delivery systems for the treatment of bladder cancer2022 - LIMA, CAROLINE S.A. de; VARCA, JUSTINE P.R.O.; ALVES, VICTORIA M.; NOGUEIRA, KAMILA M.; CRUZ, CASSIA P.C.; RIAL-HERMIDA, M. ISABEL; KADLUBOWSKI, SLAWOMIR S.; VARCA, GUSTAVO H.C.; LUGAO, ADEMAR B.Bladder cancer (BC) is the tenth most common type of cancer worldwide, affecting up to four times more men than women. Depending on the stage of the tumor, different therapy protocols are applied. Non-muscle-invasive cancer englobes around 70% of the cases and is usually treated using the transurethral resection of bladder tumor (TURBIT) followed by the instillation of chemotherapy or immunotherapy. However, due to bladder anatomy and physiology, current intravesical therapies present limitations concerning permeation and time of residence. Furthermore, they require several frequent catheter insertions with a reduced interval between doses, which is highly demotivating for the patient. This scenario has encouraged several pieces of research focusing on the development of drug delivery systems (DDS) to improve drug time residence, permeation capacity, and target release. In this review, the current situation of BC is described concerning the disease and available treatments, followed by a report on the main DDS developed in the past few years, focusing on those based on mucoadhesive polymers as a strategy. A brief review of methods to evaluate mucoadhesion properties is also presented; lastly, different polymers suitable for this application are discussed.Resumo IPEN-doc 25429 The effect of radiation dose rate over the formation of protein-based nanoparticles for nanosized delivery of chemo and radiotherapeutics2018 - VARCA, G.H.C.; FAZOLIN, G.N.; FERREIRA, A.H.; OLIVEIRA, J.P.R. de; MARQUES, F.; LUGAO, A.B.Recent studies demonstrated the development of papain and bovine serum albumin nanoparticles using gamma radiation (10 kGy) in presence of 20-30% (v/v) ethanol. With the purpose of producing stable and well defined nanocarriers, this work aims to determine the influence of different dose rates over protein nanoparticle formation. For this purpose, papain and BSA nanoparticles were synthetized in phosphate buffer (50 mM, pH 7.2) and ethanol (20-30%, v/v) using a radiation dose of 10 kGy and dose rate of 0.8, 2, 5 and 10 kGy.h-1. After irradiation, samples were evaluated by dynamic light scattering, fluorescence and proteolytic activity to verify the size, secondary structure and monitoring of the enzymatic activity, respectively. For papain nanoparticles it was observed that the dose rate did not influence the particle size formation, however crosslinking evidenced by bityrosine showed that samples irradiated at 0.8 and 5 kGy.h-1 presented higher bityrosine levels. On the other hand, BSA nanoparticles presented different results if compared to papain NPs. Different dose rates caused different and non-linear size increase for each condition, following the order: 5 > 10 > 0.8 > 2 kGy.h-1. However, in terms of crosslinking formation, a linear increase was registered, as at 0.8 kGy.h-1 the smallest signal was achieved, whereas at 10 kGy.h- 1 the highest signal was recorded. In conclusion, BSA nanoparticles were more sensitive to different radiation dose rates than nanopapain. Optimized results in terms of size increase and higher bityrosine levels were observed for the samples irradiated at 5 kGy.h-1, in which nanoparticle formation will occur faster if compared to the synthesis carried out under distinct conditions. As final applications of the system concert their use for the delivery of chemo or radiotherapeutics, the loading of paclitaxel, a well-known chemotherapeutic agent, and radiolabeling with tecntetium- 99m, a radioisotope suitable for biomedical applications, have also been performed with high efficiency, thus demonstrating a proof of concept of such systems.