Plusieurs cancers sont associés à des concentrations sériques anormales de marqueurs tumoraux, tels que le prostate specific antigen (PSA) dans le cancer de prostate, l’alfafoetoproteine (AFP) ou l’human chorionic gonadotrophin (hCG) dans les tumeurs germinales ou les maladies trophoblastiques gestationnelles (MTG). Le traitement du cancer doit s’accompagner d’une chute de leurs concentrations. Les valeurs prédictives de nombreux paramètres cinétiques censés caractériser la décroissance des marqueurs ont été publiées dans la littérature (nadir, valeur seuil, demi-vie, temps à normalisation etc…) Cependant très peu de ces paramètres sont utilisés en pratique par manque de reproductibilité. La modélisation en approche de cinétique de population, déjà utilisée dans les études pharmacocinétiques, permettrait de caractériser de façon dynamique la décroissance des marqueurs tumoraux sériques et de compenser les limites des autres méthodes. Nous avons étudié la faisabilité et l’intérêt de cette approche dans 4 études portant sur le PSA après chirurgie d’adénome ou de cancer de la prostate, l’hCG-AFP dans les tumeurs germinales non-séminomateuses traitées par polychimiothérapie de type Bléomycine-Etoposide- Cisplatine (BEP) et l’hCG dans les MTG traitées par méthotrexate. La modélisation de la décroissance des marqueurs tumoraux a été possible dans toutes les études en adaptant la méthodologie aux spécificités de chaque marqueur. Il apparaît que les clairances apparentes du PSA et de l’hCG permettraient d’identifier les patients ayant des profils cinétiques défavorables et donc à haut risque de rechute. Des études de validation sur des cohortes indépendantes sont nécessaires / Several cancers are associated with abnormal serum concentrations of tumor markers such as prostate specific antigen (PSA) in prostate tumor diseases, alfa-fetoprotein (AFP) or human chorionic gonadotrophin (hCG) in germ cell tumors or persistent gestational trophoblastic diseases (GTD). Cancer treatment should induce decline of serum tumor marker concentrations. The predictive values of many kinetic parameters supposed to characterize tumor marker declines such as nadir, time-point cutoff, half-life, time to normalization etc…, have been reported in previous studies. However very few of them have been used in routine due to the lack of outcome reproducibility. Population pharmacokinetic approach-based modeling is already used in pharmacokinetic studies. It might be helpful to characterize tumor marker decline equations dynamically and overcome limitations of previous studies. The feasibility and the relevance of this approach were assessed in 4 studies involving: PSA titers in patients with prostate adenoma or cancer treated with surgery; hCG-AFP in non-seminomatous germ cell tumor patients treated with BEP regimen (Bleomycin-Etoposide-Cisplatin) and hCG in GTD patients treated with methotrexate. Tumor marker decline modeling was feasible in all studies provided the methodology was adjusted to marker specificities. Apparent clearance of hCG and PSA might enable identification of patients with unfavorable decline profiles and thereby with high risk of relapse. Confirmatory studies with independent cohorts of patients are warranted

INTRODUÇÃO: Nos pacientes com câncer de próstata considerados de baixo risco, a braquiterapia de baixa taxa de dose (BBTD) utilizando sementes de 125I é uma excelente opção, com seguimento após o tratamento, devendo ser feito por meio de medidas seriadas de PSA. A avaliação de falha bioquímica após radioterapia, definida por elevação do PSA, tem sido feita pelo critério da ASTRO (American Society for Therapeutic Radiology and Oncology) e, mais recentemente, pelo critério do consenso de Phoenix. OBJETIVOS: Avaliar a sobrevida livre de falha bioquímica (SLFB) de pacientes submetidos à BBTD pelos critérios ASTRO e Phoenix e as relações entre eles com as falhas clínicas. Correlacionar essas sobrevidas com idade, grau histológico de Gleason, estadiamento clínico, PSA inicial, porcentagem de fragmentos positivos na biópsia, invasão perineural, volume prostático na ultra-sonografia diagnóstica, hormonioterapia neoadjuvante, bounce e D90 (dose recebida por 90% do volume de próstata). MÉTODO: Estudo retrospectivo de 329 pacientes tratados, entre julho de 1998 e dezembro de 2002, no serviço de Radioterapia do Hospital Sírio-Libanês, São Paulo. Foram excluídos 18 pacientes que tinham recebido braquiterapia associada à RT externa, 18 pacientes classificados como de alto risco, 61 casos com menos de dois anos de seguimento mínimo e 12, com dados incompletos nos prontuários. Portanto, 220 pacientes formaram a base desta análise. RESULTADOS: Cento e vinte e um (55%) pacientes foram classificados como de baixo risco e 99 (45%) de risco intermediário. O seguimento mediano foi de 53,5 meses (24 a 116); 74 pacientes (33,6%) fizeram algum tipo de bloqueio hormonal por um tempo mediano de 90 dias e 66 pacientes (30%) apresentaram bounce. O tempo médio para o aparecimento do bounce foi de 15 meses, com um nadir médio de 0,30ng/mL. A SLFB em cinco anos pelo critério ASTRO foi de 83% e de 88,3% pelo Phoenix (p < 0,05). Para os pacientes de risco baixo e intermediário, respectivamente, 86,7% e 78,4% pela definição ASTRO (p = 0,069) e 88,5% e 77,9% de acordo com Phoenix (p = 0,016). Na análise multivariada, PSA inicial < 10 ng/mL e porcentagem de fragmentos positivos < 50% foram fatores prognósticos favoráveis em relação à falha (p < 0,05) pelo critério ASTRO. De acordo com o critério Phoenix, PSA inicial < 10 ng/mL, grau histológico de Gleason < 7, porcentagem de fragmentos positivos < 50% e grupo de baixo risco foram os fatores independentes favoráveis, preditivos de falha bioquímica (p < 0,05). CONCLUSÕES: Os dados de sobrevida livre de falha bioquímica em cinco anos para pacientes de risco baixo e intermediário desta análise foram comparáveis aos da literatura. Nesta análise, não houve diferença entre as definições ASTRO e Phoenix de falha. PSA, escore de Gleason, porcentagem de fragmentos positivos na biópsia e grupo de risco foram os fatores prognósticos independentes para falha bioquímica. / INTRODUCTION: Patients with low-risk prostate adenocarcinoma may be very well treated by low dose-rate brachytherapy (LDR) using 125I seeds. Follow-up with periodical serum prostate specific antigen (PSA) dosages is used to determine the effectiveness of treatment. Biochemical relapse may be defined either by the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, or, more recently, by the Phoenix Consensus criteria. PURPOSE: To evaluate and compare biochemical failure-free survival (BFFS) of patients treated with LDR brachytherapy using ASTRO and Phoenix criteria. Also, to correlate BFFS with age, Gleason score, clinical stage, initial PSA, percentage of positive prostate biopsies, perineural invasion, prostate volume at diagnostic ultrasound, neoadjuvant hormone therapy, bounce, and D90 (dose received by 90% of the prostate). METHODS: A cohort of 329 patients who received LDR brachytherapy for prostate cancer, between 1998 and 2002 at Hospital Sírio-Libanês, São Paulo, was retrospectively studied. Eighteen patients who received external beam irradiation were excluded, together with another 18 high-risk patients, 61 with less than 2 years minimal followup, and 12 with incomplete record data. So, 220 patients were the basis of this study. RESULTS: One hundred and twenty one (55%) were low-risk patients and 99 (45%) were intermediate-risk. Median follow-up was 53.5 months (24-116); 74 (33.6%) patients received neoadjuvant hormone therapy during a median period of 90 days, and 66 (30%) presented bounce. Mean time till bounce was 15 months, with mean nadir of 0,30ng/mL. The 5-year BFFS was 83% using ASTRO criteria, and 88.3% using Phoenix (p > 0,05). Low and intermediate-risk patients presented, respectively, 86.7% and 78.4% 5-year BFFS using ASTRO definition (p = 0,069), and 88.5% and 77.9%, considering Phoenix criteria (p = 0,016). In multivariate analysis, initial PSA < 10 ng/mL, and percentage of positive prostate biopsies < 50% were favorable prognostic factors, regarding biochemical relapse using ASTRO criteria (p < 0,05), while initial PSA < 10 ng/mL, Gleason score < 7, percentage of positive prostate biopsies < 50%, and low-risk group were detected as independent favorable prognostic factors using Phoenix definition (p < 0,05). CONCLUSIONS: The 5-year estimates of BFFS using both criteria, for low and intermediate-risk patients, were similar to previous published data, with no significant difference between them. Initial PSA, Gleason score, percentage of positive prostate biopsies, and risk group were independent prognostic factors for biochemical relapse.

O objetivo geral deste trabalho foi explorar a versatilidade de filmes multicamadas de polieletrólitos (PEM) e suas aplicações em sistemas de entrega de drogas e como filmes funcionais para aplicações biomédicas. Filmes PEM montados pela técnica de camada por camada (layer­-by­-layer, LbL), foram explorados em três aplicações principais. Na primeira, foi explorado o desenvolvimento de um protocolo de funcionalização em filmes de poli(alilamina)/poli (estireno sulfonato), PAH/SPS. Os parâmetros de construção do filme para biotinilação dos grupamentos amina do PAH foram otimizados e aplicados na captura e detecção do antígeno específico da próstata (PSA), na concentração de 100 a 0,1 ng/mL, usando pontos quânticos (Qdots). Em comparação com outros trabalhos, este sistema apresentou uma boa sensibilidade na detecção de PSA, dentro do limite de detecção clínica de 0,4 a 0,1 ng/mL. A segunda aplicação envolveu o desenvolvimento de filmes de sacrifício baseados nas interações naturais da mucina submandibular bovina e da lectina, jacalina (BSM/JAC). Filmes de BSM/JAC apresentaram estabilidade quando submetidos a uma ampla faixa de pH (pH 3-­-9) e em solução de alta força iônica (5 M NaCl). A dissolução dos filmes BSM/JAC pôde ser seletivamente desencadeada mediante à incubação em solução de melibiose, 37 °C, pH 7,4, sem apresentar citotoxicidade às células. Na última parte deste trabalho, a incorporação de lipossomos ecogênicos (ELIP) em mochilas celulares foi investigada. Mochilas celulares são \"patches\" de 7­-10 &#181;m de diâmetro que podem ser fabricados por meio de deposição alternada de polímeros utilizando-­-se a técnica de LbL, sobre uma matriz pré­-moldada obtida por fotolitografia, a fim de criar um sistema composto por três multicamadas estratificadas: uma região de liberação, para promover o destacamento do substrato, uma região de carga de droga, e uma região adesiva às células. O uso de ELIP permitiu incorporação de até 9x mais doxorrubicina (DOX) se comparado com o fármaco livre em solução absorvido pelos dos filmes. A liberação de DOX pelos filmes foi monitorado por 25 dias. Mochilas contendo ELIP-­DOX foram então aderidos a monócitos, e sua viabilidade monitorados por 72h. Mochilas vazias mostraram diminuir a proliferação de monócitos ao longo das 72 horas, enquanto mochilas carregadas com ELIP-­DOX mostraram uma diminuição dramática na população celular, apontando uma potencialização dos efeitos da droga pela sua proximidade com as células. / The overall goal of this thesis was to exploit the versatility of polyelectrolite multilayers (PEM) to be applied in drug delivery systems and biofunctionalizable films for biomedical applications. PEM films assembled by the layer-by­-layer technique were explored in three main applications. In the first part of this work, the development of a functionalization protocol of poly(allylamine)/poly(styrene sulfonate), PAH/SPS was explored. The optimal film parameters to the use of biotinylated multilayers were applied for the capture and detection of prostate specific antigen (PSA) protein in the range of 100 to 0.1 ng/mL, by using quantum dots. Compared to previous work, this system presented a good sensitivity for PSA detection that is within the clinical limit range of 0.4 to 0.1 ng/mL. The second application involved the creation of a novel sacrificial multilayer film. Films based in natural interactions of bovine submaxillary mucin and the lectin jacalin, BSM/JAC were assembled. BSM/JAC films showed stability when underwent a wide rage of pH (pH 3 to 9) and high ionic strength (5 M NaCl) solutions. BSM/JAC dissolution could be triggered released by incubation in melibiose at 37 °C in pH 7.4 buffer, without cytotoxicity. In the last part of this work the incorporation of echogenic liposomes (ELIP) into cell backpacks was investigated. Cell backpacks are 7-10 &#181;m diameter patches that can be fabricated through LbL polymer deposition onto a photopatterned array to create a stacked composite of three stratified multilayer systems: a releasable region for easy detachment from the substrate, a drug payload region, and a cell adhesive region. The use of ELIP allowed up to 9x more doxorubicin (DOX) loading when compared to free drug in solution adsorbed through the films. DOX release from films was monitored for over 25 days. ELIP­-DOX backpacks were then attached to mouse monocytes and their viability monitored by 72h. Empty backpacks showed to decrease monocytes proliferation over the course of 72h, while ELIP­-DOX backpacks showed a dramatic decrease in cell population, showing that DOX effects were enhancement in drug potency by its proximity.

Introdução - A ressecção transuretral da próstata continua sendo uma das cirurgias mais realizadas em homens com idade acima de 50 anos e é considerada o padrão-ouro no tratamento cirúrgico de pacientes com sintomas de hiperplasia prostática benigna (HPB). Embora sua eficácia no alívio dos sintomas de pacientes com HPB já tenha sido extensamente documentada, seu impacto sobre os níveis séricos de antígeno prostático específico não é bem conhecido. O objetivo do presente estudo foi avaliar o comportamento dos níveis séricos do antígeno prostático específico (PSA) em pacientes submetidos à ressecção transuretral da próstata. Métodos - No período de abril de 2003 a julho de 2004, 30 pacientes portadores de hiperplasia prostática benigna, selecionados para tratamento cirúrgico por meio de ressecção transuretral da próstata foram avaliados prospectivamente. A idade dos pacientes variou de 46 a 84 anos (mediana de 68,5 anos). A avaliação pré-operatória incluiu quantificação dos sintomas do trato urinário inferior através do escore internacional de sintomas prostáticos (IPSS), dosagem sérica do PSA total, relação de PSA livre sobre total (PSAl/t) e avaliação do peso prostático por ultrassonografia transretal. Os fragmentos ressecados na cirurgia foram pesados e submetidos a exame histopatológico com coloração pela hematoxilina-eosina. Os pacientes foram avaliados após 30, 60 e 180 dias da cirurgia com IPSS, dosagem sérica do PSA total e relação de PSAl/t. Para estudar o impacto da presença de prostatite crônica sobre os níveis de PSA, os pacientes foram divididos em dois grupos com base na presença ou ausência de prostatite e foram comparados em relação às variáveis clínicas e níveis de PSA préoperatórios bem como evolução pós-operatória dos níveis de PSA. Resultados - Na avaliação pré-operatória, o I-PSS variou de 18 a 29, com média de 22,5 ± 2,9. O PSA total variou de 0,79 ng/ml a 33,46 ng/ml com média de 6,19 ng/ml e mediana de 3,79. A relação de PSAl/t foi de 18,18% ± 3,36. O peso prostático variou de 29,0 a 130,0g com média de 71,8g. O peso dos fragmentos prostáticos ressecados variou de 11g a 102g, com média de 29,87g ± 19,58g. O I-PSS reduziu-se significantemente em todos os momentos avaliados após a cirurgia, sendo 12,6 ± 2,0 no 30º dia pósoperatório (PO); 11,6 ± 1,6 no 60º PO; e 11,3 ± 1,8 no 180º PO (p< 0,01 para todas as comparações com o IPSS pré-operatório). O PSA total reduziu-se significantemente em todos os momentos avaliados após a cirurgia em comparação com o PSA pré-operatório, sendo 2,27ng/ml ± 2,20 no 30° PO; 1,75ng/ml ± 1,66 no 60° PO e 1,79 ng/ml ± 1,26 no 180° PO (p<0,001 para todas as comparações). Houve diferença estatisticamente significante quando se comparou o PSA total do 30° PO com o 60° e 180° PO (p<0,05) mas não na comparação entre o 60° e 180° PO. A relação de PSAl/t não variou de forma significante após a cirurgia em comparação com o pré-operatório, sendo 17,78% ± 8,59 no 30° PO; 18,69% ± 9,89 no 60°, e 21 ± 7,49 % no 180° (p =0,91). No exame histopatológico, foram identificados 12 (40%) pacientes com hiperplasia prostática benigna e prostatite crônica e 18 (60%) com diagnóstico somente de hiperplasia prostática benigna. Não houve diferenças estatisticamente significantes entre os pacientes com e sem prostatite em relação aos parâmetros préoperatórios idade, I-PSS, PSAt, relação do PSAl/t e peso ressecado da próstata. Os níveis de PSA total pós-operatório variaram de 8,1ng/ml ± 10,2 para 2,4ng/ml ± 2,3; 1,6ng/ml ± 1,0 e 1,9ng/ml ± 0,9, respectivamente nos 30, 60 e 180 dias pós-operatórios, entre os pacientes com prostatite. Entre os pacientes sem prostatite, o PSA total reduziu-se de 4,9ng/ml ± 3,7 para 2,2ng/ml ± 2,2; 1,8ng/ml ± 2,0 e 1,7ng/ml ± 1,5, respectivamente nos 30, 60 e 180 dias pós-operatórios. Não houve diferença estatisticamente significante na comparação dos pacientes com e sem prostatite em nenhum dos momentos avaliados. Conclusões - Os níveis séricos de PSA total dos pacientes com hiperplasia prostática reduzem-se significantemente após a cirurgia de ressecção transuretral da próstata, atingindo o valor mínimo de estabilização após 60 dias da cirurgia. A relação de PSAl/t não é afetada pela cirurgia. A presença de prostatite crônica não tem influencia sobre a evolução dos níveis séricos de PSA. Estes achados deverão ajudar no seguimento de pacientes submetidos à ressecção transuretral da próstata / Introduction - Transurethral resection of the prostate (TURP) remains as one of the most common surgeries in men over 50 years old and is considered the gold standard in the surgical treatment of patients with benign prostatic hyperplasia (BPH). Although its efficacy in the relief of lower urinary symptoms in patients with BPH have been extensively demonstrated, it is not clear how it affects the serum levels of prostate-specific antigen (PSA). The objective of this study was to evaluate the progression of the serum levels of PSA after TURP in patients with BPH. Materials - From April 2003 to July 2004, 30 patients with BPH were selected for TURP and were prospectively evaluated. The age of the patients varied from 46 to 84 years (median 68,5 years). Preoperative evaluation included quantification of the lower urinary tract symptoms with the international prostatic symptom score (IPSS), assessment of the serum levels of total and free PSA and evaluation of the prostate weight bytransrectal ultrasound. Prostate fragments resected in the surgery were weighed and histologically evaluated. Postoperatively, patients were evaluated after 30, 60 and 180 days of the surgery, with IPSS, free-tototal PSA ratio (PSAf/t). To evaluate the influence of the presence of chronic prostatitis on the PSA levels, patients were divided in two groups based on the presence or absence of prostatitis and compared in terms of preoperative clinical variables and PSA levels as well as the postoperative progression of the PSA levels. Results - In the preoperative evaluation, I-PSS varied from 18 to 29, with a mean of 22,5 ± 2,9. Total PSA levels varied from 0,79 ng/ml to 33,46 ng/ml with a mean of 6,19 ng/ml and median of 3,79. The mean PSAf/t ration was 18,18% ± 3,36. Prostate weight varied from 29,0 to 130,0g with a mean of 71,8g. Resected prostate weight varied from 11g to 102g, mean 29,87g ± 19,58g. A significant decrease of the IPSS was observed in all moments of postoperative evaluation, with a mean of 12,6 ± 2,0 on the 30th postoperative day (PO); 11,6 ± 1,6 on the 60 PO and 11,3 ± 1,8 on the 180 PO (p< 0,01 for all comparisons with the preoperative IPSS). Total PSA was significantly reduced in all moments of postoperative evaluation in comparison with the preoperative levels, with a mean of 2,27ng/ml ± 2,20 on the 30 PO; 1,75ng/ml ± 1,66 on the 60 PO and 1,79 ng/ml ± 1,26 on the 180 PO (p<0,001 for all comparisons). A significant difference was observed in the PSA levels of the 30 PO in comparison with the 60 and 180 PO (p<0,05) but not in the comparison of the 60 PO with 180 PO. The PSAf/t ration did not significantly varied in comparison with the preoperative values, with a mean of 17,78% ± 8,59 on the 30 PO; 18,69% ± 9,89 on the 60 PO and 21 ± 7,49 % on the 180 PO (p =0,91). On the histopathological studies, 12 (40%) patients were diagnosed with chronic prostatitis and BPH and e 18 (60%) with isolated BPH. There was no statisticaly significant differences between patients with and without prostatitis in terms of the preoperative parameters age, I-PSS, total PSA, PSAf/t ration and resected prostate weight. Among the patients with prostatitis, serum levels of total PSA varied from 8,1ng/ml ± 10,2 preoperatively, to 2,4ng/ml ± 2,3; 1,6ng/ml ± 1,0 e 1,9ng/ml ± 0,9, respectively after 30, 60 and 180 days postoperatively. Among the patients without prostatitis, serum levels of total PSA varied from 4,9ng/ml ± 3,7 preoperatively, to 2,2ng/ml ± 2,2; 1,8ng/ml ± 2,0 e 1,7ng/ml ± 1,5, respectively after 30, 60 and 180 days postoperatively. There was no significant differences between the groups in any of the evaluations. Conclusions - Serum levels of total PSA in patients with benign prostatic hyperplasia reduce significantly after transurethral resection of the prostate, reaching the lowest stabilization value 60 days after the surgery. The PSAf/t ration is not altered by the surgery. The presence of chronic prostatitis has no influence on the progression of the serum levels of total PSA. These findings should help the clinician in the management of patients submitted to transurethral resection of the prostate

INTRODUÇÃO: Nos pacientes com câncer de próstata considerados de baixo risco, a braquiterapia de baixa taxa de dose (BBTD) utilizando sementes de 125I é uma excelente opção, com seguimento após o tratamento, devendo ser feito por meio de medidas seriadas de PSA. A avaliação de falha bioquímica após radioterapia, definida por elevação do PSA, tem sido feita pelo critério da ASTRO (American Society for Therapeutic Radiology and Oncology) e, mais recentemente, pelo critério do consenso de Phoenix. OBJETIVOS: Avaliar a sobrevida livre de falha bioquímica (SLFB) de pacientes submetidos à BBTD pelos critérios ASTRO e Phoenix e as relações entre eles com as falhas clínicas. Correlacionar essas sobrevidas com idade, grau histológico de Gleason, estadiamento clínico, PSA inicial, porcentagem de fragmentos positivos na biópsia, invasão perineural, volume prostático na ultra-sonografia diagnóstica, hormonioterapia neoadjuvante, bounce e D90 (dose recebida por 90% do volume de próstata). MÉTODO: Estudo retrospectivo de 329 pacientes tratados, entre julho de 1998 e dezembro de 2002, no serviço de Radioterapia do Hospital Sírio-Libanês, São Paulo. Foram excluídos 18 pacientes que tinham recebido braquiterapia associada à RT externa, 18 pacientes classificados como de alto risco, 61 casos com menos de dois anos de seguimento mínimo e 12, com dados incompletos nos prontuários. Portanto, 220 pacientes formaram a base desta análise. RESULTADOS: Cento e vinte e um (55%) pacientes foram classificados como de baixo risco e 99 (45%) de risco intermediário. O seguimento mediano foi de 53,5 meses (24 a 116); 74 pacientes (33,6%) fizeram algum tipo de bloqueio hormonal por um tempo mediano de 90 dias e 66 pacientes (30%) apresentaram bounce. O tempo médio para o aparecimento do bounce foi de 15 meses, com um nadir médio de 0,30ng/mL. A SLFB em cinco anos pelo critério ASTRO foi de 83% e de 88,3% pelo Phoenix (p < 0,05). Para os pacientes de risco baixo e intermediário, respectivamente, 86,7% e 78,4% pela definição ASTRO (p = 0,069) e 88,5% e 77,9% de acordo com Phoenix (p = 0,016). Na análise multivariada, PSA inicial < 10 ng/mL e porcentagem de fragmentos positivos < 50% foram fatores prognósticos favoráveis em relação à falha (p < 0,05) pelo critério ASTRO. De acordo com o critério Phoenix, PSA inicial < 10 ng/mL, grau histológico de Gleason < 7, porcentagem de fragmentos positivos < 50% e grupo de baixo risco foram os fatores independentes favoráveis, preditivos de falha bioquímica (p < 0,05). CONCLUSÕES: Os dados de sobrevida livre de falha bioquímica em cinco anos para pacientes de risco baixo e intermediário desta análise foram comparáveis aos da literatura. Nesta análise, não houve diferença entre as definições ASTRO e Phoenix de falha. PSA, escore de Gleason, porcentagem de fragmentos positivos na biópsia e grupo de risco foram os fatores prognósticos independentes para falha bioquímica. / INTRODUCTION: Patients with low-risk prostate adenocarcinoma may be very well treated by low dose-rate brachytherapy (LDR) using 125I seeds. Follow-up with periodical serum prostate specific antigen (PSA) dosages is used to determine the effectiveness of treatment. Biochemical relapse may be defined either by the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, or, more recently, by the Phoenix Consensus criteria. PURPOSE: To evaluate and compare biochemical failure-free survival (BFFS) of patients treated with LDR brachytherapy using ASTRO and Phoenix criteria. Also, to correlate BFFS with age, Gleason score, clinical stage, initial PSA, percentage of positive prostate biopsies, perineural invasion, prostate volume at diagnostic ultrasound, neoadjuvant hormone therapy, bounce, and D90 (dose received by 90% of the prostate). METHODS: A cohort of 329 patients who received LDR brachytherapy for prostate cancer, between 1998 and 2002 at Hospital Sírio-Libanês, São Paulo, was retrospectively studied. Eighteen patients who received external beam irradiation were excluded, together with another 18 high-risk patients, 61 with less than 2 years minimal followup, and 12 with incomplete record data. So, 220 patients were the basis of this study. RESULTS: One hundred and twenty one (55%) were low-risk patients and 99 (45%) were intermediate-risk. Median follow-up was 53.5 months (24-116); 74 (33.6%) patients received neoadjuvant hormone therapy during a median period of 90 days, and 66 (30%) presented bounce. Mean time till bounce was 15 months, with mean nadir of 0,30ng/mL. The 5-year BFFS was 83% using ASTRO criteria, and 88.3% using Phoenix (p > 0,05). Low and intermediate-risk patients presented, respectively, 86.7% and 78.4% 5-year BFFS using ASTRO definition (p = 0,069), and 88.5% and 77.9%, considering Phoenix criteria (p = 0,016). In multivariate analysis, initial PSA < 10 ng/mL, and percentage of positive prostate biopsies < 50% were favorable prognostic factors, regarding biochemical relapse using ASTRO criteria (p < 0,05), while initial PSA < 10 ng/mL, Gleason score < 7, percentage of positive prostate biopsies < 50%, and low-risk group were detected as independent favorable prognostic factors using Phoenix definition (p < 0,05). CONCLUSIONS: The 5-year estimates of BFFS using both criteria, for low and intermediate-risk patients, were similar to previous published data, with no significant difference between them. Initial PSA, Gleason score, percentage of positive prostate biopsies, and risk group were independent prognostic factors for biochemical relapse.

A indicação de biópsia para o diagnóstico precoce do câncer prostático baseia-se na dosagem sérica do PSA e nos achados do toque retal. O PSA é uma kalecreina estando seus genes reguladores ligados aos andrógenos. Drogas que afetam o metabolismo dos andrógenos podem afetar a produção de PSA. A finasterida é uma droga sintética que inibe a conversão de testosterona em DHT pela enzima 5 AR. O uso da finasterida na dose de 5mg/dia para o tratamento da HPB causa redução do volume prostático de 20 a 30% e diminuição dos valores dos PSA em aproximadamente 50% do seu valor inicial após 6 meses. O uso da finasterida na dose de 1mg/dia para o tratamento da AAM foi aprovado pelo FDA em 1997. Um estudo realizado em 2007 avaliou a alteração do nível do PSA em homens com mais de 40 anos fazendo uso de finasterida 1mg/dia para tratamento da AAM. Os resultados revelaram redução dos valores do PSA semelhante à verificada nos pacientes portadores de HPB. Não existem estudos prospectivos sobre o tema incluindo pacientes mais jovens. O objetivo do nosso trabalho foi verificar as alterações da dosagem do PSA, da testosterona sérica total e do volume prostático em indivíduos com menos de 40 anos de idade com em uso de finasterida 1mg/dia. Selecionamos 52 pacientes que após avaliação inicial preenchiam os critérios de inclusão. Foram dosados os níveis séricos do PSA e da testosterona, e mensurado o volume prostático através da ultrassonografia transabdominal, no início do estudo (T0) e um ano após o uso da finasterida (T2). No intervalo, 6 meses após o início da droga, foi solicitada apenas nova dosagem de PSA (T1). O valor médio na avaliação inicial (T0) da dosagem do PSA, da testosterona total plasmática e do volume prostático mensurado pela ultrassonografia transabdominal foi de 0,398 ng/ml (0,14- 0,78); 735,77 ng/dl (548-927) e 21,35 ml (15-31ml) respectivamente. Foi observada uma redução do valor médio do PSA de 9,21% após 6 meses do uso da droga (p=0,001). Após 12 meses do uso da finasterida verificamos uma redução de 10,51% do valor do PSA em relação à dosagem inicial (p<0,001) e uma diminuição do valor médio do volume prostático 21,37 ml para 20,03 ml (p<0,001). Não foi detectada alterações nos níveis de testosterona. Diferentemente de estudos anteriores em que, em homens fazendo uso de finasterida 1mg/dia, houve redução de 40% e 50% dos valores do PSA nas faixas etárias de 40 a 49 anos e 50 a 59 anos, nosso trabalho revelou reduções inferiores. Nosso estudo traz importantes questionamentos em relação a como deve ser feita a correção dos valores do PSA nos pacientes que começaram a utilizar finansterida 1mg antes dos 40 anos de idade e que se apresentam para avaliação prostática. Outro ponto de interesse é se a hiperplasia do componente epitelial observada durante envelhecimento masculino poderia ser inibida pelo uso da finasterida desde a juventude, pois sabemos que indivíduos portadores de deficiência congênita de 5AR não apresentam alopecia e nem tão pouco desenvolvem HPB. / The indication of biopsy for early diagnosis of prostate cancer is based on serum PSA levels and digital rectal examination findings. PSA is a kalecreine and its regulatory genes are modulating by androgens. Drugs affecting the androgens metabolism can affect the production of PSA. Finasteride is a synthetic drug, which inhibits the conversion of testosterone to DHT by the enzyme 5 AR. There are two subtypes of 5AR enzymes, Type 1 that predominates in non-prostatic tissues such as liver and skin, and Type 2, which predominates in the prostate and scalp but is also expressed in other tissues. The use of Finasteride 5mg / day for the treatment of BPH is well known. After six months we observe a decrease in prostate volume by 20 to 30% and also a decrease in total serum PSA concentration of approximately 50%. The use of Finasteride at 1mg / day for the treatment of MAA has been approved by the FDA in 1997. In 2007 a study evaluated the change in total serum PSA concentration in men over 40 years taking Finasteride 1 mg / day to treat MAA. The results showed a reduction in PSA values similar to that observed in patients treated of BPH. There are no prospective studies including younger patients. The aim of our study was to assess the changes in total serum PSA concentration, total serum testosterone concentration and prostate volume in patients younger than 40 years of age in use of Finasteride 1mg / day for MAA. We prospectively selected 52 patients with MAA and indication for treatment with Finasteride who met the inclusion criteria. Serum levels of total PSA and total testosterone and prostate volume, measured by transabdominal ultrasound, were obtained at baseline (T0) and one year after started the drug (T2). In the interval, 6 months after started drug, only serum total PSA concentration was measured (T1). The median value at baseline (T0), for total PSA, total testosterone and prostate volume was 0.398 ng / ml (0.14 to 0.78); 735.77 ng / dl (548-927) and 21.35 ml (15-31ml) respectively. A reduction of 9.21% on total PSA concentration was detected 6 months after started the drug (p = 0.001). After 12 months we observed a 10.51% decrease in total serum PSA concentration, when compared with the baseline value, (p <0.001). A reduction in the median value of prostate volume from 21.37 ml to 20.03 ml (p < 0.001) was also detected at the same period. There were no detectable changes in testosterone levels. They reported a decrease of 40% and 50% in total PSA concentration for groups between 40-49 and 50-59 of age respectively. In our study we observed lower reductions. Our finding may be explained by the fact that the epithelial component of the prostate gland has not yet started the hyperplasia process, so the conversion of testosterone into DHT by blocking 5AR by Finasteride would cause less impact. The fact that the values of plasma testosterone not have changed is not surprising since Finasteride is not considered an anti androgenic drug, it means that the synthesis of the testosterone is not affected by its use. Our study highlights important questions about how the adjustment of PSA values should be done in patients who began taking Finasteride 1mg / day before 40 years of age and present for prostate evaluation. Another point of interest is whether the hyperplasia of the epithelial component, observed during the aging process, could be inhibited by the use of Finasteride. This hypothesis can be corroborate by the fact that individuals with congenital deficiency of 5AR do not present alopecia or develop BPH. In conclusion the use of Finasteride 1mg /day reduces the total serum PSA value by 10,51% after one year. Prostate volume is also reduced by 6,3% in the same period.

Serial prostate-specific antigen (PSA) measurements (PSA velocity) as an additional instrument to detect prostatic cancer was introduced in 1992. It has previously been reported that PSA increase per year differed in the last 5 years prior to diagnosis in patients with benign prostatic hyperplasia (0.18 ng/ml/year), locally confined (0.75 ng/ml/year) and metastasized (4.4 ng/ml/year) cancer of the prostate (CaP) in contrast to healthy men (0.04 ng/ml/year). The ability of PSA velocity to detect organ-confined CaP in patients with intermediate PSA serum values depends therefore on a reliable and reproducible PSA result. The present study comprised 85 men with PSA values between 3 and 8 ng/ml (Abbott IMx). PSA measurements were repeated with Abbott IMx (n = 85 patients) and Hybritech Tandem-E (n = 59 patients) assays. The PSA serum values differed from one examination to the other from 0.02 to 2.74 ng/ml with the Abbott IMx. Standard deviation amounted to 0.35 ng/ml with the Abbott IMx PSA assay. Using the Hybritech Tandem-E assay, mean standard deviation was 1.15 ng/ml and therefore higher than with the Abbott IMx assay. The difference from one test to the other ranged from 0.05 to 4.05 ng/ml with the Hybritech Tandem-E. Using the Abbott IMx assay, 10.6% of all repeat measurements exceeded 1 ng/ml whereas in the Hybritech Tandem-E assay 62.7% of the second measurements differed >1 ng/ml from the first PSA result. An increase in PSA serum values may therefore be due to intratest variation, physiological day-to-day variation as well as prostatic disease. It is important to notice that the intra-assay variation may be greater than the PSA increase per year in a patient with CaP. Therefore, PSA velocity seems to be of limited value. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

This PhD aimed to elucidate the mechanisms by which polymorphisms may alter androgen-induced transactivation of androgen receptor (AR) target genes which may be important in prostate cancer aetiology. The second aspect of this PhD focused on identifying and characterising functional polymorphisms that may have utility as predictive risk indicators for prostate cancer and which may aid in earlier therapeutic intervention and better disease management. Analyses were carried out on the kallikrein-related peptidase 3 (KLK3), also known as the prostate specific antigen (PSA), gene and the kallikrein-related peptidase 4 (KLK4) gene. The PSA and KLK4 genes are part of the serine protease family that have trypsin or chymotrypsin like activity and are thought to play a role in the development of hormone-dependent cancers in tissues such as those in the prostate, breast, endometrium and ovaries. In the prostate, PSA is regulated by androgens and three androgen response elements (AREs) have been described in the promoter and upstream enhancer region. The PSA ARE I harbours a polymorphism at -158 bp from the transcription initiation site (TIS) that results in a G to A transition (G-158A). This PhD investigated the functional significance of the PSA G-158A polymorphism which has been reported to be associated with prostate cancer risk. Electromobility shift assays (EMSAs) investigating the interaction of ARE I variants with the AR DNA binding domain (AR-DBD) demonstrated that the A allele had a two-fold increased binding affinity for the AR-DBD when compared with the G allele. This was confirmed with endogenous AR in limited proteolysis-EMSA experiments. The limited proteolysis-EMSA experiments also demonstrated differential sensitivities of PSA ARE I alleles to trypsin digestion, which suggests that the G-158A polymorphism has an allosteric effect on the AR that alters AR/ARE I complex stability. Furthermore, Chromatin Immunoprecipitation (ChIP) assays suggest that the A allele more readily recruited the AR in vivo when compared with the G allele and is consistent with the in vitro binding data. Luciferase reporter assays carried out in both LNCaP and 22Rv1 prostate cancer cells, and using the natural (dihydrotestosterone; DHT) ligand demonstrated that the A allele was more responsive to androgens in LNCaP cells. Hence, this study has elucidated the potential mechanisms by which the G-158A polymorphism may differentially regulate PSA expression (of which up-regulation of PSA is thought to be important in prostate cancer development and progression). KLK4 has similar tissue-restricted expression as PSA and is up-regulated by steroid hormones in many endocrine cells including those in the prostate. A putative ARE (KLK4-pARE) located at -1,005 to -1019 relative to the more predominantly used transcription initiation site, TIS3, was initially found in supershift assays using AR antibodies to interact with endogenous AR. However, subsequent EMSA analysis using purified AR-DBD suggest that KLK4-pARE may be interacting with the AR indirectly. To investigate this hypothesis, a tandem construct of KLK4-pARE was cloned into the pGL3-Promoter vector for hormone-induced reporter assays. However, reporter assays did not demonstrate any responsiveness of KLK4-pARE to androgens, estradiol or progestins. Consequently, Real-Time PCR was carried out to reassess the hormonal regulation of KLK4 at the mRNA level. Consistent with the literature, data from this study suggests that KLK4 may be up-regulated by androgens, progestins and estradiol in a cyclical manner. Hormone-induced luciferase reporter assays were then carried out on seven promoter constructs that span 2.8 kb of the KLK4 promoter from TIS3. However, none of the seven promoter constructs demonstrated any significant responsiveness to androgens, estradiol or progestins. This study suggests that hormone response elements (HREs) that may drive the hormonal regulation of KLK4 in prostate cancer may be located further upstream from the promoter region investigated in this PhD, or alternatively, may lie 3' of TIS3. The characterisation of KLK4 promoter polymorphisms and their flanking sequences were also carried out in parallel to the functional work with the intent to assess the functional significance of any polymorphisms that may be located within HREs. In total 19 polymorphisms were identified from the public databases and from direct sequencing within 2.8 kb of the KLK4 promoter from TIS3. However, the functional and clinical significance of these 19 polymorphisms were not further pursued given the negative findings from the functional work. The PSA AR enhancer region was also assessed for potential polymorphisms that may be associated with prostate cancer risk. A total of 12 polymorphisms were identified in the PSA enhancer of which two (A-4643G and T-5412C) have been reported to alter functionality of the enhancer region and thus, prioritised for further analysis. Association analysis for prostate cancer risk was then carried out on these PSA enhancer polymorphisms as none of the KLK4 promoter polymorphisms were found in functional HREs. No significant association for either the A-4643G or T-5412C polymorphism with prostate cancer risk was found at the P = 0.05 level. However, under an age-adjusted dominant model a 1.22- (95% CI = 1.16-1.26) and 1.23-fold (95% CI = 1.17-1.29) increased risk for prostate cancer was found for the A-4643G or T-5412C polymorphisms, respectively. Both polymorphisms were also assessed for association with tumour grade and stage and PSA levels. Genotypes were significantly different for the A-4643G and T-5412C polymorphisms with tumour stage and PSA levels, respectively. However, these results are likely to be biased by the case population which consist primarily of men who presented with incidental (pT1) and organ-confined (pT2) tumours. To summarise, the A-4643G and T-5412C polymorphisms are unlikely to be associated with prostate cancer risk, PSA levels or stage/grade of disease. However, further analyses in a larger cohort is warranted given that these polymorphisms alter androgen responsiveness of the PSA enhancer and that elevated PSA levels are indicative of men with prostate cancer. To summarise, this PhD has elucidated the functional significance of the PSA G-158A polymorphism in prostate cancer and which may be important in prostate cancer patho-physiology. This PhD has also furthered the understanding of the hormonal regulation of KLK4 in prostate cancer cells. Finally, this PhD has carried out a pilot study on two functional PSA enhancer polymorphisms (A-4643G and T-5412C) with prostate cancer risk.

A indicação de biópsia para o diagnóstico precoce do câncer prostático baseia-se na dosagem sérica do PSA e nos achados do toque retal. O PSA é uma kalecreina estando seus genes reguladores ligados aos andrógenos. Drogas que afetam o metabolismo dos andrógenos podem afetar a produção de PSA. A finasterida é uma droga sintética que inibe a conversão de testosterona em DHT pela enzima 5 AR. O uso da finasterida na dose de 5mg/dia para o tratamento da HPB causa redução do volume prostático de 20 a 30% e diminuição dos valores dos PSA em aproximadamente 50% do seu valor inicial após 6 meses. O uso da finasterida na dose de 1mg/dia para o tratamento da AAM foi aprovado pelo FDA em 1997. Um estudo realizado em 2007 avaliou a alteração do nível do PSA em homens com mais de 40 anos fazendo uso de finasterida 1mg/dia para tratamento da AAM. Os resultados revelaram redução dos valores do PSA semelhante à verificada nos pacientes portadores de HPB. Não existem estudos prospectivos sobre o tema incluindo pacientes mais jovens. O objetivo do nosso trabalho foi verificar as alterações da dosagem do PSA, da testosterona sérica total e do volume prostático em indivíduos com menos de 40 anos de idade com em uso de finasterida 1mg/dia. Selecionamos 52 pacientes que após avaliação inicial preenchiam os critérios de inclusão. Foram dosados os níveis séricos do PSA e da testosterona, e mensurado o volume prostático através da ultrassonografia transabdominal, no início do estudo (T0) e um ano após o uso da finasterida (T2). No intervalo, 6 meses após o início da droga, foi solicitada apenas nova dosagem de PSA (T1). O valor médio na avaliação inicial (T0) da dosagem do PSA, da testosterona total plasmática e do volume prostático mensurado pela ultrassonografia transabdominal foi de 0,398 ng/ml (0,14- 0,78); 735,77 ng/dl (548-927) e 21,35 ml (15-31ml) respectivamente. Foi observada uma redução do valor médio do PSA de 9,21% após 6 meses do uso da droga (p=0,001). Após 12 meses do uso da finasterida verificamos uma redução de 10,51% do valor do PSA em relação à dosagem inicial (p<0,001) e uma diminuição do valor médio do volume prostático 21,37 ml para 20,03 ml (p<0,001). Não foi detectada alterações nos níveis de testosterona. Diferentemente de estudos anteriores em que, em homens fazendo uso de finasterida 1mg/dia, houve redução de 40% e 50% dos valores do PSA nas faixas etárias de 40 a 49 anos e 50 a 59 anos, nosso trabalho revelou reduções inferiores. Nosso estudo traz importantes questionamentos em relação a como deve ser feita a correção dos valores do PSA nos pacientes que começaram a utilizar finansterida 1mg antes dos 40 anos de idade e que se apresentam para avaliação prostática. Outro ponto de interesse é se a hiperplasia do componente epitelial observada durante envelhecimento masculino poderia ser inibida pelo uso da finasterida desde a juventude, pois sabemos que indivíduos portadores de deficiência congênita de 5AR não apresentam alopecia e nem tão pouco desenvolvem HPB. / The indication of biopsy for early diagnosis of prostate cancer is based on serum PSA levels and digital rectal examination findings. PSA is a kalecreine and its regulatory genes are modulating by androgens. Drugs affecting the androgens metabolism can affect the production of PSA. Finasteride is a synthetic drug, which inhibits the conversion of testosterone to DHT by the enzyme 5 AR. There are two subtypes of 5AR enzymes, Type 1 that predominates in non-prostatic tissues such as liver and skin, and Type 2, which predominates in the prostate and scalp but is also expressed in other tissues. The use of Finasteride 5mg / day for the treatment of BPH is well known. After six months we observe a decrease in prostate volume by 20 to 30% and also a decrease in total serum PSA concentration of approximately 50%. The use of Finasteride at 1mg / day for the treatment of MAA has been approved by the FDA in 1997. In 2007 a study evaluated the change in total serum PSA concentration in men over 40 years taking Finasteride 1 mg / day to treat MAA. The results showed a reduction in PSA values similar to that observed in patients treated of BPH. There are no prospective studies including younger patients. The aim of our study was to assess the changes in total serum PSA concentration, total serum testosterone concentration and prostate volume in patients younger than 40 years of age in use of Finasteride 1mg / day for MAA. We prospectively selected 52 patients with MAA and indication for treatment with Finasteride who met the inclusion criteria. Serum levels of total PSA and total testosterone and prostate volume, measured by transabdominal ultrasound, were obtained at baseline (T0) and one year after started the drug (T2). In the interval, 6 months after started drug, only serum total PSA concentration was measured (T1). The median value at baseline (T0), for total PSA, total testosterone and prostate volume was 0.398 ng / ml (0.14 to 0.78); 735.77 ng / dl (548-927) and 21.35 ml (15-31ml) respectively. A reduction of 9.21% on total PSA concentration was detected 6 months after started the drug (p = 0.001). After 12 months we observed a 10.51% decrease in total serum PSA concentration, when compared with the baseline value, (p <0.001). A reduction in the median value of prostate volume from 21.37 ml to 20.03 ml (p < 0.001) was also detected at the same period. There were no detectable changes in testosterone levels. They reported a decrease of 40% and 50% in total PSA concentration for groups between 40-49 and 50-59 of age respectively. In our study we observed lower reductions. Our finding may be explained by the fact that the epithelial component of the prostate gland has not yet started the hyperplasia process, so the conversion of testosterone into DHT by blocking 5AR by Finasteride would cause less impact. The fact that the values of plasma testosterone not have changed is not surprising since Finasteride is not considered an anti androgenic drug, it means that the synthesis of the testosterone is not affected by its use. Our study highlights important questions about how the adjustment of PSA values should be done in patients who began taking Finasteride 1mg / day before 40 years of age and present for prostate evaluation. Another point of interest is whether the hyperplasia of the epithelial component, observed during the aging process, could be inhibited by the use of Finasteride. This hypothesis can be corroborate by the fact that individuals with congenital deficiency of 5AR do not present alopecia or develop BPH. In conclusion the use of Finasteride 1mg /day reduces the total serum PSA value by 10,51% after one year. Prostate volume is also reduced by 6,3% in the same period.

O objetivo geral deste trabalho foi explorar a versatilidade de filmes multicamadas de polieletrólitos (PEM) e suas aplicações em sistemas de entrega de drogas e como filmes funcionais para aplicações biomédicas. Filmes PEM montados pela técnica de camada por camada (layer­-by­-layer, LbL), foram explorados em três aplicações principais. Na primeira, foi explorado o desenvolvimento de um protocolo de funcionalização em filmes de poli(alilamina)/poli (estireno sulfonato), PAH/SPS. Os parâmetros de construção do filme para biotinilação dos grupamentos amina do PAH foram otimizados e aplicados na captura e detecção do antígeno específico da próstata (PSA), na concentração de 100 a 0,1 ng/mL, usando pontos quânticos (Qdots). Em comparação com outros trabalhos, este sistema apresentou uma boa sensibilidade na detecção de PSA, dentro do limite de detecção clínica de 0,4 a 0,1 ng/mL. A segunda aplicação envolveu o desenvolvimento de filmes de sacrifício baseados nas interações naturais da mucina submandibular bovina e da lectina, jacalina (BSM/JAC). Filmes de BSM/JAC apresentaram estabilidade quando submetidos a uma ampla faixa de pH (pH 3-­-9) e em solução de alta força iônica (5 M NaCl). A dissolução dos filmes BSM/JAC pôde ser seletivamente desencadeada mediante à incubação em solução de melibiose, 37 °C, pH 7,4, sem apresentar citotoxicidade às células. Na última parte deste trabalho, a incorporação de lipossomos ecogênicos (ELIP) em mochilas celulares foi investigada. Mochilas celulares são \"patches\" de 7­-10 &#181;m de diâmetro que podem ser fabricados por meio de deposição alternada de polímeros utilizando-­-se a técnica de LbL, sobre uma matriz pré­-moldada obtida por fotolitografia, a fim de criar um sistema composto por três multicamadas estratificadas: uma região de liberação, para promover o destacamento do substrato, uma região de carga de droga, e uma região adesiva às células. O uso de ELIP permitiu incorporação de até 9x mais doxorrubicina (DOX) se comparado com o fármaco livre em solução absorvido pelos dos filmes. A liberação de DOX pelos filmes foi monitorado por 25 dias. Mochilas contendo ELIP-­DOX foram então aderidos a monócitos, e sua viabilidade monitorados por 72h. Mochilas vazias mostraram diminuir a proliferação de monócitos ao longo das 72 horas, enquanto mochilas carregadas com ELIP-­DOX mostraram uma diminuição dramática na população celular, apontando uma potencialização dos efeitos da droga pela sua proximidade com as células. / The overall goal of this thesis was to exploit the versatility of polyelectrolite multilayers (PEM) to be applied in drug delivery systems and biofunctionalizable films for biomedical applications. PEM films assembled by the layer-by­-layer technique were explored in three main applications. In the first part of this work, the development of a functionalization protocol of poly(allylamine)/poly(styrene sulfonate), PAH/SPS was explored. The optimal film parameters to the use of biotinylated multilayers were applied for the capture and detection of prostate specific antigen (PSA) protein in the range of 100 to 0.1 ng/mL, by using quantum dots. Compared to previous work, this system presented a good sensitivity for PSA detection that is within the clinical limit range of 0.4 to 0.1 ng/mL. The second application involved the creation of a novel sacrificial multilayer film. Films based in natural interactions of bovine submaxillary mucin and the lectin jacalin, BSM/JAC were assembled. BSM/JAC films showed stability when underwent a wide rage of pH (pH 3 to 9) and high ionic strength (5 M NaCl) solutions. BSM/JAC dissolution could be triggered released by incubation in melibiose at 37 °C in pH 7.4 buffer, without cytotoxicity. In the last part of this work the incorporation of echogenic liposomes (ELIP) into cell backpacks was investigated. Cell backpacks are 7-10 &#181;m diameter patches that can be fabricated through LbL polymer deposition onto a photopatterned array to create a stacked composite of three stratified multilayer systems: a releasable region for easy detachment from the substrate, a drug payload region, and a cell adhesive region. The use of ELIP allowed up to 9x more doxorubicin (DOX) loading when compared to free drug in solution adsorbed through the films. DOX release from films was monitored for over 25 days. ELIP­-DOX backpacks were then attached to mouse monocytes and their viability monitored by 72h. Empty backpacks showed to decrease monocytes proliferation over the course of 72h, while ELIP­-DOX backpacks showed a dramatic decrease in cell population, showing that DOX effects were enhancement in drug potency by its proximity.