Browsing by Author "Anjos, I."
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- Characterization of a novel 3D-polymeric scaffold as a co-delivery systemPublication . Zegre, Miguel; Silveira, M.; Anjos, I.; Ribeiro, I. A.; Santos, C.; Caetano, Liliana Aranha; Gonçalves, L.; Bettercourt, A.Osteomyelitis is an inflammation of the bone caused by infection, leading to necrosis and tissue destruction. It can cause persistent morbidity and become a chronic disease, being one of the infectious diseases most difficult to manage. Staphylococcus aureus is the most usual causative pathogen in osteomyelitis, and bacterial infections are often complicated by concomitant fungal infections, Candida sp. being the most common. Co-encapsulation of drugs provides a convenient means for the administration of multiple drugs directed at commonly associated diseases. Three-dimensional scaffolds have become a crucial element of bone tissue engineering and regenerative medicine, are designed to provide an ideal environment for bone formation. Thus, this work aims to develop a new local drug-delivery system for the modulation of polymicrobial activity in bone infections, through the co-delivery of minocycline and voriconazole to the local site of infection, while fostering bone repair.
- Evaluation of a dual function minocycline polymeric bone scaffoldPublication . Anjos, I.; Zegre, Miguel; Santos, C.; Alves, M. M.; Ribeiro, I.; Gonçalves, L.; Bettencourt, A. F.It is estimated that orthopedic procedures will rise due to population growth along with aging and increasing chronic diseases. Consequently, orthopedic infections associated with these procedures can be a serious complication, leading to a state of morbidity. Current strategies for treating bone infections and defects present several limitations, namely low local concentrations and systemic toxicity. To overcome these limitations, synthetic and biocompatible bone grafts substitutes (scaffolds) are being developed as platforms for local drug delivery, a strategy that allows high antibiotics concentration in bone for orthopedic infections treatment. Thus, this work aims to develop a drug delivery system with osteoconductive and osteoinductive properties for bone regeneration and capable of treating the infection. For this purpose, porous PDLLA scaffolds were produced by the solvent casting technique, functionalized with bioglass (BG) and collagen (Col), and loaded with 0.5, 0.25, 0.1, or 0.05 mg/mL of minocycline hydrochloride (MH), a dual function drug that beyond its antibiotic role, also induce osteoblastic cells differentiation. Scaffolds’ surface morphology was characterized by scanning electron microscopy (SEM) and elemental chemical composition was performed by X-ray energy dispersive spectrometer (EDS). These drug delivery systems were also characterized in terms of drug release profiles and cytocompatibility through in vitro studies. SEM analysis demonstrated a porous surface and confirmed the functionalization. Regarding drug release profiles, the obtained results suggest a two-phase stage release, with an initial burst release of approximately 60%, 30%, and 10% of MH in the first 15 min, for the two most MH concentrated groups, 0.1 mg/mL of MH group and 0.05 mg/mL of MH group, respectively, followed by a sustained release. In vitro cell studies were promising for scaffolds adsorbed with 0.1 and 0.05 mg/mL of MH, not revealing cytotoxicity, contrary to what was seen for scaffolds with higher concentrations of MH (0.5 and 0.25 mg/mL).In conclusion, due to release profiles of the drug and in vitro cell assays, scaffolds adsorbed with the two lowest MH concentrations seem a promising strategy for acute infection treatment, however, antimicrobial assays must be conducted.