Rosanna Ignazzi

Probing the dynamics of complexed local anesthetics via neutron scattering spectroscopy and DFT calculations

Since potential changes in the dynamics and mobility of drugs upon complexation for delivery may affect their ultimate efficacy, we have investigated the dynamics of two local anesthetic molecules, bupivacaine (BVC, C18H28N2O) and ropivacaine (RVC, C17H26N2O), in both their crystalline forms and complexed with water-soluble oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). The study was carried out by neutron scattering spectroscopy, along with thermal analysis, and density functional theory computation. Mean square displacements suggest that RVC may be less flexible in crystalline form than BVC, but both molecules exhibit very similar dynamics when confined in HP-β-CD. The use of vibrational analysis by density functional theory (DFT) made possible the identification of molecular modes that are most affected in both molecules by insertion into HP-β-CD, namely those of the piperidine rings and methyl groups. Nonetheless, the somewhat greater structure in the vibrational spectrum at room temperature of complexed RVC than that of BVC, suggests that the effects of complexation are more severe for the latter. This unique approach to the molecular level study of encapsulated drugs should lead to deeper understanding of their mobility and the respective release dynamics.

Restricted mobility of specific functional groups reduces anti-cancer drug activity in healthy cells.

The most common cancer treatments currently available are radio- and chemo-therapy. These therapies have, however, drawbacks, such as, the reduction in quality of life and the low efficiency of radiotherapy in cases of multiple metastases. To lessen these effects, we have encapsulated an anti-cancer drug into a biocompatible matrix. In-vitro assays indicate that this bio-nanocomposite is able to interact and cause morphological changes in cancer cells. Meanwhile, no alterations were observed in monocytes and fibroblasts, indicating that this system might carry the drug in living organisms with reduced clearance rate and toxicity. X-rays and neutrons were used to investigate the carrier structure, as well as to assess the drug mobility within the bio-nanocomposite. From these unique data we show that partial mobility restriction of active groups of the drug molecule suggests why this carrier design is potentially safer to healthy cells.

Encapsulation effects on the structure-dynamics on drug carriers revealed by neutron scattering

Universidade Estadual Paulista Julio de Mesquita Filho, Departamento de Quimica, Instituto de Biociencias, Botucatu, Distrito de Rubiao Junior, Rubiao Junior, CEP 18618000, SP, Brasil

Raman and Infrared spectroscopies and X-ray diffraction data on bupivacaine and ropivacaine complexed with 2-hydroxypropyl−β−cyclodextrin

The data presented in this article are related to the research article entitled “Probing the dynamics of complexed local anesthetics via neutron scattering spectroscopy and DFT calculations (http://dx.doi.org/10.1016/j.ijpharm.2017.03.051)” (Martins et al., 2017) [1]. This work shows the molecular and structural behavior of the local anesthetics (LAs) bupivacaine (BVC, C18H28N2O) and ropivacaine (RVC, C17H26N2O) before and after complexation with the water-soluble oligosaccharide 2-hydroxypropyl−β−cyclodextrin (HP-β-CD).