ANDRE LUIS LAPOLLI

ANDRE LUIS LAPOLLI

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Microfluidic circuit applied to the concentration of 18F for the production of radiopharmaceuticals
2023 - GOMES, ANTONIO A.; NARIO, ARIAN P.; LAPOLLI, ANDRE L.; LANDULFO, E.; BERNARDES, EMERSON S.; ROSSI, WAGNER de
Introduction: Microfluidics is becoming a promising technology for synthesizing [18F]-labeled radiopharmaceuticals, reducing costs, reagents, and increasing activity [1]. Conversely, current commercial production of such radiopharmaceuticals for clinical diagnosis by positron emission tomography (PET) imaging requires dedicated and expensive equipment, only available in specialized facilities to produce only one type of 18F radiopharmaceutical [2]. So, as the demand for PET increases, the use of microfluidics becomes essential for this commercial production, and, in this sense, this work presents the results of a developed “micro-cartridge” microfluidic chip applied to the 18F retention and elution process that can improve all the production aspects. Methodology: The micro-cartridge was machined in borosilicate optical glass – BK7 using the ultrashort pulse laser ablation technique. After micromachining, the micro-cartridge is filled with the same resin used in the conventional anionic synthesis cartridge (Waters Accel Plus QMA Light cartridge). Both are later submitted to comparative performance tests to evaluate the radiochemical efficiency in the 18F retention and elution phase between them. Results and discussion: Four comparative tests were performed for both phases (first stage of synthesis of radiopharmaceuticals labeled with 18F), with activities (55.5 ± 11.1 Mbq and 9.2 ± 0.4 Gbq; n = 2). The results showed that the micro-cartridge is equivalent to the conventional cartridge (QMA Plus Light) in the retention phase, presenting a radiochemical efficiency of 99.3% ± 0.7 vs 99.6% ± 0.3, respectively. However, in the 18F elution phase, the micro-cartridge showed a radiochemical efficiency of 93% ± 0.2, and the conventional cartridge had a maximum of 77.4% ± 15.5, showing the great advantage of the micro-cartridge. The hypothesis that supports the superiority of the results of micro-cartridge efficiencies in the elution phase is the high surface-volume ratio, which leads to the prevalence of surface phenomena such as mass transfers and faster reaction syntheses, which occur in microfluidic systems. Although the microfluidic systems studied for radiopharmaceuticals have existed for almost 20 years, the use of the ultrashort pulse laser technique and the type of material used in the micro-cartridge development are not commonly reported. Conclusions: Integrating an anion exchange micro-cartridge on a chip with the ultrashort pulse laser ablation technique opens the door to smaller, and more efficient radiopharmacy chips for producing 18F radiopharmaceuticals. The first unprecedented experimental results in Brazil demonstrate that the initial stages of production of ready-to-use doses for humans (pre-concentration of fluorine) can be carried out with greater efficiency in the elution parameters of 18F compared to synthesis with a conventional cartridge.
Microfluídica, uma tecnologia aplicada à concentração de 18F para produção de radiofármacos
2023 - GOMES, ANTONIO A.; NARIO, ARIAN P.; LAPOLLI, ANDRE L.; LANDULFO, EDUARDO; BERNARDES, EMERSON S.; ROSSI, WAGNER de
Introdução. O uso de radiofármacos marcados com 18F para o diagnóstico clínico por imagem PET (tomografia por emissão de pósitrons) de diversas doenças tem aumentado consideravelmente. O maior radiofármaco aplicado a diagnósticos com PET é o [18F]-2-desoxi-2-fluoro-D-glicose (FDG) e a sua preparação requer a utilização de equipamentos especializados (e caros) para proteger o farmacêutico que o prepara. Assim, à medida que a demanda de radiofármacos PET aumentar, colocará uma pressão significativa nas instalações de produção de traçadores PET, a qual necessitará de investimento em novas tecnologias de produção de radiofármacos. Uma tecnologia chave desenvolvida nos últimos tempos tem sido o uso de sistemas microfluídicos. Os dispositivos microfluídicos oferecem muitas vantagens para a síntese de radiofármacos de curta duração (por exemplo, 18F)tais como: reações mais rápidas, transferência de calor eficiente, alta relação superfície – volume e rendimentos mais elevados. Embora os sistemas microfluídicos estudados para radiofármacos existam há quase 20 anos, no Brasil, até onde sabemos, esta tecnologia e estudo é inédita. Objetivos. Apresentar os primeiros resultados no desenvolvimento de um chip microfluídico para uma “microcoluna” destinada ao processo de retenção e eluição de 18F. Metodologia. A microcoluna foi usinada em vidro óptico de borosilicato – BK7 utilizando a técnica de ablação com laser de pulsos ultracurtos. Após a microusinagem, a microcoluna é preenchida com a mesma resina utilizada no cartucho convencional de síntese “Sep-Pak Accell Plus QMA Plus Light” da fabricante Waters™. Ambas são posteriormente submetidas a testes de desempenho comparativos de eficiência na fase de retenção e eluição de 18F. Resultados. Foram realizados 4 testes comparativos para ambas as fases (primeira etapa da síntese de 18F-FDG), com atividades (1,5 ± 0,3 mCi e 248 ± 11 mCi; “n = 2”). Os resultados demostraram que a eficiência da microcoluna é equivalente à da coluna convencional (QMA Plus Light) na fase de retenção (99,3% ± 0,67 vs99,6% ± 0,32). No entanto, na fase de eluição de 18F, houve uma diferença significativa entre ambas (99,93% ±0,18 vs 77,38% ± 15,54), destacando a grande vantagem da microcoluna. Conclusão. A integração do cartucho de troca iônica em um chip, com a técnica de ablação com laser de pulso ultracurto, abre as portas para chips de radiofarmácia menores e mais eficientes para a produção de 18F-FDG e outros compostos. Os resultados experimentais inéditos no Brasil demonstram que as etapas iniciais da produção de doses prontas para humanos (pré-concentração de flúor) podem ser realizadas com uma eficiência superior nos parâmetros de eluição do 18Fem comparação a síntese com cartucho convencional.
A new 124Xe irradiation system for 123I production
2023 - COSTA, OSVALDO L. da; BARCELLOS, HENRIQUE; MATSUDA, HYLTON; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.; MATSUDA, MARGARETH M.N.; LAPOLLI, ANDRE L.
Since 2001, Nuclear and Energy Research Institute IPEN-CNEN has produced weekly ultrapure iodine-123, using a manual irradiation system, fully developed in IPEN. Iodine-123 radiopharmaceuticals have been produced and distributed to hospitals and clinics of nuclear medicine, where several diagnostic imaging procedures for thyroid, brain and cardiovascular functions are performed. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. In the present work, the technical and constructive aspects of a new fully automated irradiation system, dedicated to 123I routine production, employing enriched xenon-124 gas as the target material is presented. This new system consists of a target, a water and helium cooling system, a cryogenic system, an electric power system, and a control and process monitoring unit, composed of supervisory software, connected to a programmable logic controller via personal computer. In this new concept, there is no need for human intervention during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. By using this new system, a specific yield of 2.70 mCi/μAh per irradiation was achieved in validation runs, and after three years of routine production of iodine- 123, the system showed reliability and resilience.
Design and assembly of an XY-type beam current monitor for cyclotron accelerators
2023 - BARCELLOS, HENRIQUE; MATSUDA, HYLTON; LAPOLLI, ANDRE L.; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.; COSTA, OSVALDO L. da
A water-cooled XY-type beam current monitor was designed, manufactured and assembled in a cyclotron accelerator beam transport line. Tests were performed, demonstrating that apparatus is an instrument of great assistance in proton beam position. The XY-type beam current monitor has been widely used in liquid target irradiations, employing irradiation system which were originally designed for irradiations on 18 MeV cyclotron accelerator (Cyclone 18, IBA) only, however, with this apparatus, the target may be exchanged between the 30 MeV (Cyclone 30, IBA) and 18 MeV cyclotrons.
A closer look at the synthesis of 2‑[18F] fluoroethyl tosylate to minimize the formation of volatile side‑products
2022 - PIJEIRA, MARTHA S.O.; SANTOS, SOFIA N. dos; ARAUJO, YASNIEL B.; LAPOLLI, ANDRE L.; WANDERMUREN, MARCIO N.; RIERA, ZALUA R.; CARVALHO, IVONE; ELSINGA, PHILIP H.; BERNARDES, EMERSON S.
Background: 2-[18F]Fluoroethyltosylate ([18F]FEtOTs) is a well-known 18F-fluoroalkylating agent widely used to synthesize radiotracers for positron emission tomography. The widespread use of [18F]FEtOTs is due in part to its low volatility when compared to other halide and sulfonate building blocks. In this work, the radioactive volatile side-products formed during the synthesis of [18F]FEtOTs were identified and characterized for the first time, and an optimization of the reaction conditions to minimize their formation was proposed. Results: In order to characterize the volatiles produced during [18F]FEtOTs synthesis, the reaction mixtures of both cold FEtOTs and [18F]FEtOTs were co-injected onto the HPLC system. The radioactive peaks corresponding to the volatile compounds were collected, analyzed through headspace gas chromatography mass spectrometry sampler (HS-GC–MS) and identified as vinyl fluoride ([19F]VF) and 2-fluoroethanol ([19F]FEOH). By using a rotatable central composite design with a two-level full factorial core of two factors (22), it was determined that temperature and time are independent variables which affect the generation of [18F]VF and [18F]FEOH during the radiosynthesis of [18F]FEtOTs. In addition, in order to reduce the formation of the volatiles ([18F]VF and [18F]FEOH) and increase the yield of [18F]FEtOTs, it was demonstrated that the molar ratio of base to precursor must also be considered. Conclusion: [18F]VF and [18F]FEOH are volatile side-products formed during the radiosynthesis of [18F]FEtOTs, whose yields depend on the reaction time, temperature, and the molar ratio of base to precursor. Therefore, special care should be taken during the radiosynthesis and subsequent reactions using [18F]FEOTs in order to avoid environmental contamination and to improve the yield of the desired products.
Synthesis of a 2‑nitroimidazole derivative N‑(4‑[18F]fluorobenzyl)‑2‑(2‑nitro‑1H‑imidazol‑1‑yl)‑acetamide ([18F]FBNA) as PET radiotracer for imaging tumor hypoxia
2022 - NARIO, ARIAN P.; WOODFIELD, JENILEE; SANTOS, SOFIA N. dos; BERGMAN, CODY; WUEST, MELINDA; ARAUJO, YASNIEL B.; LAPOLLI, ANDRE L.; WEST, FREDERICK G.; WUEST, FRANK; BERNARDES, EMERSON S.
Background: Tissue hypoxia is a pathological condition characterized by reducing oxygen supply. Hypoxia is a hallmark of tumor environment and is commonly observed in many solid tumors. Non-invasive imaging techniques like positron emission tomography (PET) are at the forefront of detecting and monitoring tissue hypoxia changes in vivo. Results: We have developed a novel 18F-labeled radiotracer for hypoxia PET imaging based on cytotoxic agent benznidazole. Radiotracer N-(4-[18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)acetamide ([18F]FBNA) was synthesized through acylation chemistry with readily available 4-[18F]fluorobenzyl amine. Radiotracer [18F]FBNA was obtained in good radiochemical yields (47.4 ± 5.3%) and high radiochemical purity (> 95%). The total synthesis time was 100 min, including HPLC purification and the molar activity was greater than 40 GBq/µmol. Radiotracer [18F]FBNA was stable in saline and mouse serum for 6 h. [18F]FBNA partition coefficient (logP = 1.05) was found to be more lipophilic than [18F]EF-5 (logP = 0.75), [18F]FMISO (logP = 0.4) and [18F]FAZA (logP = − 0.4). In vitro studies showed that [18F]FBNA accumulates in gastric cancer cell lines AGS and MKN45 under hypoxic conditions. Conclusions: Hence, [18F]FBNA represents a novel and easy-to-prepare PET radioligand for imaging hypoxia.
Validity studies among hierarchical methods of cluster analysis using cophenetic correlation coefficient
2019 - CARVALHO, P.R.; MUNITA, C.S.; LAPOLLI, A.L.
The literature presents many methods to produce data set clusters and the better method choice becomes hardest because the various combinations between them based on different dissimilarity measures can lead to different cluster patterns and false interpretations. Nevertheless, little effort has been expended in evaluating these methods empirically using an archeological data set. In this way, this work has the objective to develop a comparative study of the cluster analysis methods and to identify what is the most appropriate for an archeological data set. For this, 45 ceramic fragments samples data set was analyzed by instrumental neutron activation analysis (INAA). And, five hierarchical methods of cluster were used to this data set: Single linkage, Complete linkage, Average linkage, Centroid and Ward. The validation was done calculating cophenetic correlation coefficient values by a statistical program R and the comparison between them showed the average linkage method was more accurate for the 45 ceramic fragments samples data set. With this, the statistical program R showed be an tool option for other scientists to calculate their cophenetic correlation coefficient and to identify the more accurate methods for their archeological data set.
Comparative study of hierarchical clustering
2017 - CARVALHO, P.R.; MUNITA, C.S.; LAPOLLI, A.L.
In archaeological studies several analytical techniques are used to study the chemical and mineralogical composition of many materials of archaeological origin, generating a large data set. Thus, the multivariate statistical methods become indispensable for the interpretation of the results. These multivariate techniques, unsupervised and supervised, are accompanied by modern computational programs, which provide visualization and interpretation. Several methods have been used, such as cluster analysis, discriminant analysis, principal component analysis, among others. However, the most used is cluster analysis. The purpose of cluster analysis is to group the samples based on similarity or dissimilarity. The groups are determined in order to obtain homogeneity within the groups and heterogeneity between them. The literature presents many methods for partitioning of data set, and is difficult choose which is the most suitable, since the various combinations of methods based on different measures of dissimilarity can lead to different patterns of grouping and false interpretations. Nevertheless, little effort has been expended in evaluating these methods empirically using an archaeological data set. In this way, the objective of this work is make a comparative study of the different cluster analysis methods and to identify which is the most appropriate. For this, the study was carried out using a data set of the Archaeometric Studies Group from IPEN-CNEN/SP, in which 45 samples of ceramic fragments from three archaeological sites were analyzed by instrumental neutron activation analysis (INAA) which were determinated the mass fraction of 13 elements (As, Ce, Cr, Eu, Fe, Hf, La, Na, Nd, Sc, Sm, Th, U). The methods used for this study were: single linkage, complete linkage, average linkage, centroid and Ward. The comparison was done using the cophenetic correlation coefficient and according these values the average linkage method obtained better results. A script of the statistical program R was created to obtain the cophenetic correlation coefficient. The purpose of this script is to facilitate the statistical study of researchers who do not have much familiarity with statistical programs.Therefore, the researcher can easily check which method is most appropriate for your data set.
Control system and automation of the spectrum acquisition for a perturbed gamma-gamma angular correlation spectrometer
2017 - STACHOWSKI, ADEMIR F.A.; LAPOLLI, ANDRE L.; CARBONARI, ARTUR W.; SAXENA, RAJENDRA N.
This work reports results from the automation of data acquisition for a gamma-gamma perturbed angular correlation (PAC) spectrometer located in the hyperfine interactions laboratory (LIH) of IPEN. A PAC spectrometer comprises usually four scintillation detectors (BaF3 for example) and carries out time measurements from gamma rays of any two combinations of detectors in coincidence. Gamma rays come from the decay of probe nuclei embedded into the material to be studied. Measurements are generally performed as a function of temperature. The fourth-detectors PAC spectrometer was automated in Java language because it is a multiplatform and object oriented programming language, having, therefore, portability and longer lifetime due to the ease of implementation of peripherals. Finally, the software has a friendly and intuitive interface with the user being able to operate the hardware manually or automatically with time acquisitions up to 100 consecutive hours. Before each acquisition, the software sets the temperature, waits for temperature stability and records data in different files. Moreover, the software also saves in a file all information of relevant parameters during acquisition.
A new 124Xe irradiation system for 123I routine production at the 30 MeV IPEN-CNEN/SP cyclotron
2017 - LAPOLLI, ANDRE L.; BARCELLOS, HENRIQUE; MATSUDA, HYLTON; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.
Since 2001 the Nuclear and Energy Research Institute (IPEN/CNEN-SP, Brazil) has produced about 2.5 mCi/mAh of 123I weekly using a manual irradiation system fully developed by its researchers. Ultrapure 123I has been produced and distributed to hospitals and clinics where several diagnostic imaging procedures are done for thyroid, brain and cardiovascular functions. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. Currently IPEN researchers are involved in the development of a new fully automated irradiation system dedicated to 123I routine production employing enriched xenon gas (124Xe) as the target material. This new system consists of a target port, a water and a helium cooling system, a cryogenic system, an electric power system, a control and process monitoring unit composed of a supervisory software connected to a Programmable Logic Controller (PLC) via personal computer. In this new concept, there is no need for human interference during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. In this way, with this new system, a specific yield of approximately 3.5 mCi/mAh per irradiation is expected and this will meet a large part of the national demand for this important radioisotope. In the present work will be presented all the technical and constructive aspects of this new system as well as the results obtained in the irradiation of tests.

ANDRE LUIS LAPOLLI

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