| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 3.99 MB | Adobe PDF |
Advisor(s)
Abstract(s)
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.
Description
FCT_Pest-UID/DTP/04138/2014. CQE project_UID/QUI/00100/2013.
Keywords
Bone regeneration Scaffolds Local drug delivery Polymeric bone FCT_Pest-UID/DTP/04138/2014 CQE project_UID/QUI/00100/2013
Citation
Anjos I, Zegre M, Santos C, Alves MM, Ribeiro I, Gonçalves L, et al. Evaluation of a dual function minocycline polymeric bone scaffold. In: 11th iMed.ULisboa Postgraduate Students Meeting & 4th i3DU Meeting, Faculdade de Farmácia da Universidade de Lisboa (Portugal), July 15, 2019.