Synthesis and Evaluation of 177Lu-DOTA-DN(PTX)-BN for Selective and Concomitant Radio and Drug—Therapeutic E ect on Breast Cancer Cells

The peptide-receptor radionuclide therapy (PRRT) is a successful approach for selectively delivering radiation within tumor sites through specific recognition of radiolabeled peptides by overexpressed receptors on cancer cell surfaces. The e cacy of PRRT could be improved by using polymeric radio- and drug- therapy nanoparticles for a concomitant therapeutic e ect on malignant cells. This research aimed to prepare and evaluate, a novel drug and radiation delivery nanosystem based on the 177Lu-labeled polyamidoamine (PAMAM) dendrimer (DN) loaded with paclitaxel (PTX) and functionalized on the surface with the Lys1Lys3(DOTA)-bombesin (BN) peptide for specific targeting to gastrin-releasing peptide receptors (GRPr) overexpressed on breast cancer cells. DN was first conjugated covalently to BN and DOTA (chemical moiety for lutetium-177 complexing) and subsequently loaded with PTX. The characterization by microscopic and spectroscopic techniques, in-vitro drug delivery tests as well as in in-vitro and in-vivo cellular uptake of 177Lu-DOTA-DN(PTX)-BN by T47D breast cancer cells (GRPr-positive), indicated the formation of an improved delivery nanosystem with target-specific recognition by GRPr. Results of the 177Lu-DOTA-DN(PTX)-BN e ect on T47D cell viability (1.3%, compared with 10.9% of 177Lu-DOTA-DN-BN and 14.0% of DOTA-DN-(PTX)-BN) demonstrated the concomitant radiotherapeutic and chemotherapeutic properties of the polymeric nanosystem as a potential agent for the treatment of GRPr-positive tumors.This study was supported by the grant CONACyT-CB-A1S38087 and the International Atomic Energy Agency (CRP-F2264). It was performed as part of the activities of the “Laboratorio Nacional de Investigación y Desarrollo de Radiofármacos, CONACyT”

Engineered rHDL Nanoparticles as a Suitable Platform for Theranostic Applications

Reconstituted high-density lipoproteins (rHDLs) can transport and specifically release drugs and imaging agents, mediated by the Scavenger Receptor Type B1 (SR-B1) present in a wide variety of tumor cells, providing convenient platforms for developing theranostic systems. Usually, phospholipids or Apo-A1 lipoproteins on the particle surfaces are the motifs used to conjugate molecules for the multifunctional purposes of the rHDL nanoparticles. Cholesterol has been less addressed as a region to bind molecules or functional groups to the rHDL surface. To maximize the efficacy and improve the radiolabeling of rHDL theranostic systems, we synthesized compounds with bifunctional agents covalently linked to cholesterol. This strategy means that the radionuclide was bound to the surface, while the therapeutic agent was encapsulated in the lipophilic core. In this research, HYNIC-S-(CH2)3-S-Cholesterol and DOTA-benzene-p-SC-NH-(CH2)2-NH-Cholesterol derivatives were synthesized to prepare nanoparticles (NPs) of HYNIC-rHDL and DOTA-rHDL, which can subsequently be linked to radionuclides for SPECT/PET imaging or targeted radiotherapy. HYNIC is used to complexing 99mTc and DOTA for labeling molecules with 111, 113mIn, 67, 68Ga, 177Lu, 161Tb, 225Ac, and 64Cu, among others. In vitro studies showed that the NPs of HYNIC-rHDL and DOTA-rHDL maintain specific recognition by SR-B1 and the ability to internalize and release, in the cytosol of cancer cells, the molecules carried in their core. The biodistribution in mice showed a similar behavior between rHDL (without surface modification) and HYNIC-rHDL, while DOTArHDL exhibited a different biodistribution pattern due to the significant reduction in the lipophilicity of the modified cholesterol molecule. Both systems demonstrated characteristics for the development of suitable theranostic platforms for personalized cancer treatment.Consejo Nacional de Ciencia y Tecnología (CONACyT, Mexico), through Grant SEP-CONACyT-CB-2016-01-287217. the financing program for female scientists EDOMEX, Grant Number FICDTEM-2021-015

177Lu-Dendrimer conjugated to folate and bombesin with gold nanoparticles in the dendritic cavity: A potential theranostic radiopharmaceutical

177Lu-labeled nanoparticles conjugated to biomolecules have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this research was to synthesize 177Lu-dendrimer(PAMAM-G4)-folate-bombesin with gold nanoparticles (AuNPs) in the dendritic cavity and to evaluate the radiopharmaceutical potential for targeted radiotherapy and the simultaneous detection of folate receptors (FRs) and gastrin-releasing peptide receptors (GRPRs) overexpressed in breast cancer cells. p-SCN-Benzyl-DOTA was conjugated in aqueous-basic medium to the dendrimer.The carboxylate groups of Lys1Lys3(DOTA)-bombesin and folic acid were activatedwithHATUand also conjugated to the dendrimer.The conjugate was mixed with 1%HAuCl4 followed by the addition of NaBH4 and purified by ultrafiltration. Elemental analysis (EDS), particle size distribution (DLS), TEM analysis, UV-Vis, and infrared and fluorescence spectroscopies were performed. The conjugate was radiolabeled using 177LuCl3 or 68GaCl3 and analyzed by radio-HPLC. Studies confirmed the dendrimer functionalization with high radiochemical purity (>95%). Fluorescence results demonstrated that the presence ofAuNPs in the dendritic cavity confers useful photophysical properties to the radiopharmaceutical for optical imaging. Preliminary binding studies in T47D breast cancer cells showed a specific cell uptake (41.15 ± 2.72%). 177Ludendrimer( AuNP)-folate-bombesin may be useful as an optical and nuclear imaging agent for breast tumors overexpressing GRPR and FRs, as well as for targeted radiotherapy.CONACYT-SEP-CB-2014-01-242443 International Atomic Energy Agency (Grant 18358) LaboratorioNacional de Investigaci´on yDesarrollo de Radiof´armacos, CONACy

Fluorescent, Plasmonic, and Radiotherapeutic Properties of the 177Lu–Dendrimer-AuNP–Folate–Bombesin Nanoprobe Located Inside Cancer Cells

The integration of fluorescence and plasmonic properties into one molecule is of importance in developing multifunctional imaging and therapy nanoprobes. The aim of this research was to evaluate the fluorescent properties and the plasmonic–photothermal, therapeutic, and radiotherapeutic potential of 177Lu–dendrimer conjugated to folate and bombesin with gold nanoparticles in the dendritic cavity (177Lu–DenAuNP–folate–bombesin) when it is internalized in T47D breast cancer cells. The intense near-Infrared (NIR) fluorescence emitted at 825 nm from the conjugate inside cells corroborated the usefulness of DenAuNP–folate–bombesin for optical imaging. After laser irradiation, the presence of the nanosystem in cells caused a significant increase in the temperature of the medium (46.8oC, compared to 39.1oC without DenAuNP–folate–bombesin, P < 0.05), resulting in a significant decrease in cell viability (down to 16.51% + 1.52%) due to the 177Lu–DenAuNP–folate–bombesin plasmonic properties. After treatment with 177Lu–DenAuNP–folate–bombesin, the T47D cell viability decreased 90% because of the radiation-absorbed dose (63.16 + 4.20 Gy) delivered inside the cells. The 177Lu–DenAuNP–folate–bombesin nanoprobe internalized in cancer cells exhibited properties suitable for optical imaging, plasmonic–photothermal therapy, and targeted radiotherapy.CONACYT-SEP-CB-2014-01-24244

Synthesis and in vitro evaluation of an antiangiogenic cancerspecific dual-targeting 177Lu-Au-nanoradiopharmaceutical

The aim of this research was to synthesize and chemically characterize a cancer-specific 177Lu-Aunanoradiopharmaceutical based on gold nanoparticles (NPs), the nuclear localization sequence (NLS)-Arg-Gly- Asp peptide and an aptamer (HS-pentyl-pegaptanib) to target both the a(v)b(3) integrin and the vascular endothelial growth factor (VEGF) overexpressed in the tumor neovasculature, as well as to evaluate by the tube formation assay, the nanosystem capability to inhibit angiogenesis. 177Lu-NP-RGD-NLS-Aptamer was obtained with a radiochemical purity of 99 ± 1%. Complete inhibition of tube formation (angiogenesis) was demonstrated when endothelial cells (EA.hy926), cultured in a 3D-extracellular matrix support, were treated with the developed nanosystem.Mexican National Council of Science and Technology (CONACYT-SEP-CB-2014-01-242443)

EVALUACIÓN IN VIVO DE LA BIODISTRIBUCIÓN VOLUMÉTRICA DE BIOSENSORES PARA MEDICIÓN DE LA ACTIVIDAD METABÓLICA POR CORRELACIÓN DE RAYOS X, FLUORESCENCIA, IMAGEN CERENKOV Y RADIOISOTÓPICA.

En el presente trabajo se realiz´o la caracterizaci ´on volum´etrica in vivo de tres biosensores de folato a trav´es de la adquisici ´on de im´agenes de diferentes modalidades (rayos X, fluorescencia, luminiscencia Cerenkov e imagen radioisot ´opica) y el desarrollo de un algoritmo de reconstrucci ´on tridimensional (3D). El sistema multimodal de imagen precl´ınica Xtreme, junto con el sistema de rotaci ´on multimodal de animales (MARS por sus siglas en ingl´es), fueron utilizados para adquirir las im´agenes bidimensionales (2D). Estas im´agenes capturadas fueron procesadas para obtener la reconstrucci ´on 3D de ´organos de inter´es. Se adquirieron im´agenes de ratones a diferentes tiempos (distribuci ´on del biosensor) en las 4 distintas modalidades. La transformada inversa de Radon y la retroproyecci ´on filtrada fueron las t´ecnicas utilizadas para la reconstrucci ´on. El algoritmo desarrollado en Matlab® permiti ´o en una primera instancia, reconstruir en forma 3D la estructura del esqueleto de los ratones bajo estudio. Posteriormente, el algoritmo fue capaz de cuantificar los perfiles volum´etricos de 99mTc-Folato-Bombesina (imagen radioisot ´opica), 177Lu-Folato-Bombesina (imagen de luminiscencia Cerenkov), y FolateRSense™ 680 (imagen de fluorescencia) en los tumores y ri ˜nones de los ratones. No se detectaron diferencias significativas en las cuantificaciones volum´etricas entre t´ecnicas de medici ´on est´andar y las obtenidas por la propuesta realizada en este estudio, ni entre las captaciones volum´etricas en las estructuras de inter´es. A partir de las estructuras reconstruidas en forma 3D, se logr´o la fusi ´on de estructuras anat ´omicas (como el esqueleto) y funcionales derivadas de las im´agenes de captaci ´on de los biosensores. El algoritmo de reconstrucci ´on 3D de imagen puede ser extrapolado f´acilmente a diferentes sistemas de adquisici ´on de im´agenes 2D. ´Esta flexibilidad caracter´ıstica del algoritmo desarrollado en este estudio, es una ventaja en comparaci ´on con m´etodos similares de reconstrucci ´on reportados hasta el momento

A Therapeutic System of 177Lu-labeled Gold Nanoparticles-RGD Internalized in Breast Cancer Cells

The aim of this research was to evaluate the in vitro potential of 177 Lu-labeled gold nanoparticles conjugated to cyclo-[RGDfK(C)] peptides ( 177 Lu-AuNP-c[RGDfK(C)]) as a plasmonic photothermal therapy and targeted radiotherapy system in MCF7 breast cancer cells. Peptides were conjugated to AuNPs (20 nm) by spontaneous reaction with the thiol group of cysteine (C). After laser irradiation, the pres - ence of c[RGDfK(C)]-AuNP in cells caused a significant increase in the temperature of the medium (50.5 °C, compared to 40.3 °C without AuNPs) resulting in a significant decrease in MCF7 cell viability down to 9 %. After treatment with 177 Lu-AuNP-c[RGDfK(C)], the MCF7 cell proliferation was significantly inhibited

Adaptation and validation of scales to measure self-efficacy and empowerment for self-care in Mexican climacteric stage women.

Objective. To adapt and validate in Spanish of Mexico scales to measure self-efficacy (SES) and empowerment for self-care (ES) among climacteric women. Materials and methods. The study was conducted from February to July 2011 in two family medicine clinics in Mexico City. The adaptation phase was done through testing for language comprehension. To validate the scales we used the principal Axis factoring analysis with oblique rotation technique and estimation of Cronbach’s alpha (CA). Results. Three hundred eighty women aged 45-59 years participated in the study. SES had 16 items with four factors: participation in the doctor-patient relationship; in the study control of mental health and sexual changes; risk of dying from cancer, and other health risks that explained 39.8% of the variability, CA= 0.84. ES had eight items with one factor explaining 47.1% variability; CA= 0.83. Conclusion. Both scales had acceptable psychometric properties and are suitable for interventions aimed at improving self-care of climacteric women

Síntesis y evaluación del radiofármaco 99mTc-EDDA/HYNIC-Gly-Gly-Cys-(a,y)-Folato

El ácido fólico reconoce específicamente al receptor folato (RF) sobreexpresado en carcinomas. Los radiofármacos de folato tienen afinidad por RF pero alta captación renal. La secuencia Gly-Gly-Cys mejora la eliminación renal. El objetivo fue sintetizar el 99mTc-EDDA/HYNIC-Gly-Gly-Cys(α,γ)-Folato y evaluar su potencial in vitro e in vivo para reconocer RF. El conjugado se caracterizó químicamente (UV-Vis, FT- IR , MALDI-TOF) y se radiomarcó con 99mTc . La afinidad in vitro y la biodistribución se evaluaron en células T47D (FR+) y en ratones atímicos con tumores inducidos. 99mTc-EDDA/HYNICGly-Gly-Cys(α,γ)-Folato mostró alta pureza radioquímica (> 94 %) , afinidad por los RF (IC50=0.3nM), rápida eliminación sanguínea, captación tumoral adecuada (2.4 % ID/g a 2h) , y retención renal baja (1.6 % ID/g a 24 h). 99mTc-EDDA/HYNICGly-Gly-Cys(α,γ)-Folato es útil como un agente de imagen para reconocer RF

Development of a new prostate cancer theranostic radiopharmaceutical

Prostate cancer (PCa) is the second leading cause of cancer deaths for adult men in the Western world. Although radical prostatectomy and local radiotherapy are largely successful for patients with localized cancer, available treatments for metastatic PCa have demonstrated weak curative efficacy. Consequently, new tools to improve the detection of recurrent PCa, and to identify and treat metastases, are imperatively needed. Antibody-based constructs represent a good strategy to develop theranostic agents. Currently, the murine mAb 111In-capromab pendetide (ProstaScint\uae) is the only product that has been approved by the Food and Drug Administration (FDA) as a diagnostic radiopharmaceutical for PCa. ProstaScint\uae showed promising results in clinical diagnosis, but as a whole antibody exhibits low tumour targeting with a maximum uptake at 6-7 days post-injection and delayed clearance from non-target tissues. These issues limit its use as theranostic agent. Recently, preclinical studies of an anti-PSMA single-chain variable fragment of IgGD2B mAb (scFvD2B) la- belled with 123I, showed high tumour affinity, improved antigen-positive tumour uptake, with shorter circulatory half-life, and decreased uptake in non-target tissues. The aim of this work was to develop a new PCa theranostic radiopharmaceutical based on the scFvD2B radiolabel with 177Lu. The scFvD2B was conjugated to the chelating agent DOTA by using different stoichiometric molar ratios. The number of DOTA per scFvD2B and the affinity constant (Kd) for each construct was determined to choose the conjugated with higher specific targeting activity against PSMA receptors. The select DOTA-scFvD2B conjugate was labelled with 177LuCl3. Stability of 177Lu-DOTA-scFvD2B was studied using HPLC analysis after incubation at 37 \u2103 with fresh hu- man serum, cysteine, glutathione or EDTA solutions (300-fold excess), at time points ranging from 0.5 to 192 h. In vitro cell studies were performed to determine the binding specificity and cellular internalization of 177Lu-DOTA-scFvD2B. Biodistribution studies were performed in both healthy and PCa-bearing mice to evaluate 177Lu-DOTA-scFvD2B pharmacokinetics and assess its tumour detection potential using SPECT imaging. DOTA-scFvD2B Kd values showed that the construct characterized by 1:5 (scFvD2B:DOTA) molar ratio is the one with the greatest number of DOTA per scFvD2B which maintains the high specificity for the PSMA receptor. 177Lu-DOTA-scFvD2B possessed high in vitro stability, the radiochemical purity of the radioconjugate accomplished at 192 hours after dilution was higher than 98%. Biodistribution studies performed in healthy mice after intravenous administration of the radioconjugate demonstrated that DOTA did not significantly change the scFvD2B pharmacokinetic properties. Indeed, 177Lu-DOTA-scFvD2B showed a favourable biokinetic profile with a rapid blood clearance. Moreover, SPECT/CT imaging studies carried out in mice bearing PCa tumours in lungs proved good and specific tumour detection properties of 177Lu-DOTA-scFvD2B from 6 to 192 hours post-injection. In conclusion, 177Lu-DOTA-scFvD2B high stability and specific affinity for the PSMA receptors in vitro and in vivo make this radioconjugate a promising PCa theranostic radiopharmaceutical. However, further dosimetric studies have to be performed to establish its therapeutic potential