Browsing by Author "Reis, Ana Catarina Almeida"
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- Development of gold-core silica shell nanospheres coated with poly-2-ethyl-oxazoline and β-cyclodextrin aimed for cancer therapyPublication . Reis, Ana Catarina Almeida; Rodrigues, Ana Carolina Félix; Moreira, André; Jacinto, Telma A.; Ferreira, Paula; Correia, I.J.Cancer is one of the major world public health problems and the currently available treatments are nonspecific and ineffective. This reality highlights the importance of developing novel therapeutic approaches. In this field, multifunctional nanomedicines have the potential to revolutionize the currently available treatments. These unique nanodevices can simultaneously act as therapeutic and imaging agents allowing the real-time monitoring of the nanoparticles biodistribution and the treatment outcome. Among the different nanoparticles, the gold-core silica shell (AuMSS) nanoparticles advantageous physicochemical and biological properties make them promising nanoplatforms for cancer therapy. Nevertheless, their successful application as an effective cancer nanomedicine is limited by the unfavorable pharmacokinetics and uncontrolled release of the therapeutic payloads. Herein, a new polymeric coating for AuMSS nanospheres was developed by combining different ratios (25/75, 50/50 and 75/25) of two materials, Poly-2-ethyl-2-oxazoline (PEOZ) and β-cyclodextrin (β-CD). The surface functionalization of AuMSS nanospheres led to a size increase and to the neutralization of the surface charge. On the other side, the nanoparticles biological performance was improved. The coated AuMSS nanospheres showed an increased cytocompatibility and internalization rate by the HeLa cancer cells. Overall, the obtained data confirm the successful modification of the AuMSS nanospheres with PEOZ and β-CD as well as their promising properties for being applied in cancer therapy.
- Development of poly-2-ethyl-2-oxazoline coated gold-core silica shell nanorods for cancer chemo-photothermal therapyPublication . Moreira, André; Rodrigues, Ana Carolina Félix; Reis, Ana Catarina Almeida; Costa, Elisabete C.; Ferreira, Paula; Correia, Ilídio Joaquim SobreiraAim: Develop a new poly-2-ethyl-2-oxazoline (PEOZ)-based coating for doxorubicin-loaded gold-core mesoporous silica shell (AuMSS) nanorods application in cancer chemo-photothermal therapy. Methods: PEOZ functionalized AuMSS nanorods were obtained through the chemical grafting on AuMSS of a PEOZ silane derivative. Results: The PEOZ chemical grafting on the surface of AuMSS nanorods allowed the neutralization of nanodevices’ surface charge, from -30 to -15 mV, which improved nanoparticles’ biocompatibility, namely by decreasing the blood hemolysis to negligible levels. In vitro antitumoral studies revealed that the combined treatment mediated by the PEOZ-coated AuMSS nanorods result in a synergistic effect, allowing the complete eradication of cervical cancer cells. Conclusion: The application of the PEOZ coating improves the AuMSS nanorods performance as a multifunctional combinatorial therapy for cervical cancer.
- Gold-core silica shell nanoparticles application in imaging and therapy: A reviewPublication . Moreira, André; Rodrigues, Ana Carolina Félix; Reis, Ana Catarina Almeida; Costa, Elisabete C.; Correia, Ilídio Joaquim SobreiraNanomaterials have assumed a prominent role in biomedical field during the past years. Particularly, the gold-core silica shell nanoparticles present unique physical and chemical properties that make nanodevices appealing for theragnostic applications. The gold core characteristic X-ray attenuation, surface enhanced raman scattering and tunable absorption in the near-infrared region supports the applicability of these systems in X-ray, photoacoustic and thermal imaging as well as in photothermal and photodynamic based therapies. Additionally, the inclusion of the silica shell stabilizes the gold core, protecting it from premature degradation and aggregation, and also provides additional cargo capacity for therapeutic molecules. Further, both silica and gold are described as biocompatible, inert and nontoxic materials. In this review, an overview of the gold core-silica shell nanoparticles applications in nanomedicine is provided, highlighting the different particle shapes and their application in bioimaging and therapy. Further, the basics of the gold core-silica shell nanoparticles synthesis procedures, general properties, and biosafety are also described.