Browsing by Author "Soares, Telma"
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- A biophysical approach to formulation development: drug-plasma protein interactionPublication . Fernandes, Eduarda; Soares, Telma; Oliveira, M.E.C.D. Real; Lopes, Carla Martins; Lúcio, MarleneIn this work, the binding constant of ACV to human serum albumin was determined by binding isotherms. Nonlinear leastsquares best fit to intrinsic fluorescence quenching effect of the drug was used to determine the association constants between drug and the serum protein at one affinity binding site (Kb=1.79x103 M-1). A red shift of the fluorescent spectra confirms association. Thermodynamic parameters for the binding indicated that electrostatic interactions are predominantly involved in the binding of this drug to human serum albumin. This was further confirmed by electrophoretic and dynamic light scattering, where a progressive charge neutralization of the protein was followed by an increase of the size of albumin-drug complex.
- Chapter 5 - Lipid-based nanocarriers for co-delivery of anticancer drugs and natural compoundsPublication . Fernandes, Eduarda; Soares, Telma; Lopes, Carla Martins; Real Oliveira, Maria Elisabete; Lúcio, Marlene
- Diclofenac’s toxicity revisited with biomimetic models and biophysical studiesPublication . Lúcio, Marlene; Lopes, Carla Martins; Fernandes, Eduarda; Soares, Telma; Real Oliveira, Maria Elisabete
- Diclofenac: topical gastrointestinal damage revisited with biomimetic models and biophysical studiesPublication . Lúcio, Marlene; Lopes, Carla Martins; Fernandes, Eduarda; Soares, Telma; Real Oliveira, Maria Elisabete
- A molecular biophysical approach to diclofenac topical gastrointestinal damagePublication . Fernandes, Eduarda; Soares, Telma; Gonçalves, Hugo; Bernstorff, Sigrid; Oliveira, Maria Real; Lopes, Carla Martins; Lúcio, MarleneDiclofenac (DCF), the most widely consumed non-steroidal anti-inflammatory drug (NSAID) worldwide, is associated with adverse typical effects, including gastrointestinal (GI) complications. The present study aims to better understand the topical toxicity induced by DCF using membrane models that mimic the physiological, biophysical, and chemical environments of GI mucosa segments. For this purpose, phospholipidic model systems that mimic the GI protective lining and lipid models of the inner mitochondrial membrane were used together with a wide set of techniques: derivative spectrophotometry to evaluate drug distribution at the membrane; steady-state and time-resolved fluorescence to predict drug location at the membrane; fluorescence anisotropy, differential scanning calorimetry (DSC), dynamic light scattering (DLS), and calcein leakage studies to evaluate the drug-induced disturbance on membrane microviscosity and permeability; and small- and wide-angle X-ray scattering studies (SAXS and WAXS, respectively), to evaluate the effects of DCF at the membrane structure. Results demonstrated that DCF interacts chemically with the phospholipids of the GI protective barrier in a pH-dependent manner and confirmed the DCF location at the lipid headgroup region, as well as DCF’s higher distribution at mitochondrial membrane contact points where the impairment of biophysical properties is consistent with the uncoupling effects reported for this drug.
- The versatility of membrane-water partitioning in pharmacokinetic modellingPublication . Fernandes, Eduarda; Soares, Telma; Almeida, A.; Benfeito, S.; Lopes, Carla Martins; Sarmento, Bruno; Borges, Fernanda; Real Oliveira, Maria Elisabete; Lúcio, Marlene