G4.5 Pamam Dendrimer-Risperidone: Biodistribution and Behavioral Changes in In Vivo Model

Dendritic polymers are considered as emerging and outstanding carriers as modern medicinal systems due to their derivatisable branched architecture and possibility to modify them in numerous ways. Here, G4.5 PAMAM dendrimers were obtained as carriers of the antipsychotic drug risperidone. Despite their extensive applicability in the pharmaceutical field, the use of dendrimers as carriers in biological systems is constrained due to their inherent associated toxicity. The biocompatibility of dendrimers and dendrimer-risperidone complexes was evaluated in vivo for biological performance. To this end, the pharmacokinetics and biodistribution after oral treatment of free risperidone and dendrimer-risperidone complexes were studied in healthy mice. Also, the behavioral changes such as locomotion, aggression, dominance in male and female mice were evaluated both after a single dose and after daily therapy for 8 days. Also, in vivo effects of risperidone and dendrimer-risperidone complexes on the locomotion of zebrafish larvae were explored. The data obtained suggest that the unmetabolized risperidone complexes increase the arrival to the brain after 90 minutes. On the other hand, behavioral studies showed an increase in the potency of the drug in animals treated with the complexesFil: Prieto, Maria Jimena. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: del Rio Zabala, Nahuel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Marotta, Cristian Hernán. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Bichara, Darío Román. Fundación Instituto Leloir; ArgentinaFil: Simonetta, Sergio Hernan. Fundación Instituto Leloir; ArgentinaFil: Chiaramoni, Nadia Silvia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Alonso, Silvia del Valle. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin

Optimization and in vivo toxicity evaluation of G4.5 PAMAM dendrimer-risperidone complexes

Risperidone is an approved antipsychotic drug belonging to the chemical class of benzisoxazole. This drug has low solubility in aqueous medium and poor bioavailability due to extensive first-pass metabolism and high protein binding (.90%). Since new strategies to improve efficient treatments are needed, we studied the efficiency of anionic G4.5 PAMAM dendrimers as nanocarriers for this therapeutic drug. To this end, we explored dendrimer-risperidone complexation dependence onsolvent concentration, pH and molar relationship. The best dendrimer-risperidone incorporation (46 risperidone molecules per dendrimer) was achieved with a mixture of chloroform:methanol 50:50 v/v solution pH 3. In addition, to explore the possible effects of this complex,in vivo studies were carried out in the zebrafish model. Changes in the development of dopaminergic neurons and motoneurons were studied using tyrosine hydroxylase and calretinin, respectively. Physiologicalchanges were studied through histological sections stained with hematoxylin-eosin to observe possible morphological brain changes. The most significant changes were observed when larvae were treated with free risperidone, and no changes were observed when larvae were treated with the complex.Fil: Prieto, Maria Jimena. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: del Rio Zabala, Nahuel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Marotta, Cristian Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Carreño Gutierrez, Hector. Universidad de Salamanca; EspañaFil: Arevalo Arevalo, Rosario. Universidad de Salamanca; EspañaFil: Chiaramoni, Nadia Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Alonso, Silvia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

Optimization and in vivo toxicity evaluation of G4.5 PAMAM dendrimer-risperidone complexes

Risperidone is an approved antipsychotic drug belonging to the chemical class of benzisoxazole. This drug has low solubility in aqueous medium and poor bioavailability due to extensive first-pass metabolism and high protein binding (.90%). Since new strategies to improve efficient treatments are needed, we studied the efficiency of anionic G4.5 PAMAM dendrimers as nanocarriers for this therapeutic drug. To this end, we explored dendrimer-risperidone complexation dependence onsolvent concentration, pH and molar relationship. The best dendrimer-risperidone incorporation (46 risperidone molecules per dendrimer) was achieved with a mixture of chloroform:methanol 50:50 v/v solution pH 3. In addition, to explore the possible effects of this complex,in vivo studies were carried out in the zebrafish model. Changes in the development of dopaminergic neurons and motoneurons were studied using tyrosine hydroxylase and calretinin, respectively. Physiologicalchanges were studied through histological sections stained with hematoxylin-eosin to observe possible morphological brain changes. The most significant changes were observed when larvae were treated with free risperidone, and no changes were observed when larvae were treated with the complex.Instituto Multidisciplinario de Biología Celula

Timeline representing the stage specificity of the effects of risperidone and DG4.5-Risp in developing zebrafish.

<p>Larvae were exposed to 5 µM risperidone or DG4.5-Risp for 24-h periods from 4 dpf or 6 dpf and subsequently rescued into a conditioned E3 medium (A). Schematic representation of the in vivo treatment (B).</p

Optimization of incubation parameters.

<p>Moles of Risp per mole of DG4.5; data obtained from incubation solutions of chloroform:methanol 50∶50 v/v in different pH conditions.</p

Drug interaction with the dendrimer. FTIR spectrum of Risp (A), DG4.5 (B) and DG4.5-Risp (C) solid state runs.

<p>Drug interaction with the dendrimer. FTIR spectrum of Risp (A), DG4.5 (B) and DG4.5-Risp (C) solid state runs.</p

Immunohistochemistry images of brain tissue.

<p>Tyrosine hydroxylase, labeled with Cy2 (green), and Calretinin, labeled with Cy3 (red). A) control, B) risperidone (Risp) at 4 dpf, C) Risp at 6 dpf, D) DG4.5-Risp at 4 dpf, and E) DG4.5-Risp at 6 dpf. Larvae were analyzed three times (n = 3) at 10 dpf.</p

Release profile of the drug complexed to DG4.5. The graph indicates the percentage of drug released when found in the dendrimers or free form.

<p>Release profile of the drug complexed to DG4.5. The graph indicates the percentage of drug released when found in the dendrimers or free form.</p

Evaluation of the Dendrimers-Risperidone complex formation. Absorbance Spectrum DG4.5-Risp (green) and free Risp (black) under experimental conditions determined as optimum.

<p>Evaluation of the Dendrimers-Risperidone complex formation. Absorbance Spectrum DG4.5-Risp (green) and free Risp (black) under experimental conditions determined as optimum.</p

Moles of Risp per mole of DG4.5. Data from incubation with different chloroform:methanol 50∶50 v/v molar ratios solutions at different pHs, subjected or not to an additional drying process.

<p>Moles of Risp per mole of DG4.5. Data from incubation with different chloroform:methanol 50∶50 v/v molar ratios solutions at different pHs, subjected or not to an additional drying process.</p