Browsing by Author "Diogo, Duarte Miguel De Melo"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Hyaluronic acid functionalized nanoparticles loaded with IR780 and DOX for cancer chemo-photothermal therapyPublication . Alves, Cátia; Diogo, Duarte Miguel De Melo; Sousa, Ana Rita Lima; Costa, Elisabete; Correia, IlidioIR780 is a near infrared (NIR) dye with a huge potential to be applied in cancer phototherapy and imaging. However, IR780 poor water solubility and acute cytotoxicity limit its direct use in cancer theragnostic. Herein, a novel Hyaluronic acid (HA)-based amphiphilic polymer was used, for the first time, in the preparation of polymeric nanoparticles (HPN) encapsulating IR780 aimed to be applied in breast cancer therapy. Furthermore, HPN co-encapsulating IR780 and Doxorubicin (DOX) were also produced in order to further enhance the therapeutic effectiveness of this nanoformulation. The results revealed that HPN were able to successfully encapsulate IR780 (IR-HPN) and the IR780-DOX combination (IR/DOX-HPN). Furthermore, the encapsulation of IR780 in HPN improved its absorption at 808 nm by about 2.2-fold, thereby enhancing its photothermal potential, as well as its cytocompatibility. The 2D in vitro cell uptake studies demonstrated that the nanostructures displayed a higher internalization by breast cancer cells than by normal cells. In addition, the assays performed in 3D in vitro models of breast cancer revealed that HPN can penetrate into spheroids. Furthermore, the 3D in vitro studies also demonstrated that the combined application of IR-HPN and NIR light was unable to induce cytotoxicity on spheroids. In contrast, IR/DOX-HPN produced a decrease on spheroids cells' viability, and their combination with NIR light induced an even stronger therapeutic effect, thus revealing the potential of these nanoparticles for cancer chemo-phototherapy.
- In situ green reduced graphene oxide functionalized 3D printed scaffolds for bone tissue regenerationPublication . Cabral, C.S.D.; Miguel, Sónia; Diogo, Duarte Miguel De Melo; Louro, Ricardo; Correia, IlidioThe incorporation of reduced graphene oxide (rGO) nanomaterials into scaffolds structure can be explored to enhance the properties of these 3D matrices in bone regeneration applications. However, the weak water solubility and poor colloidal stability of rGO have hindered its incorporation in blends aimed to produce scaffolds by 3D printing. Furthermore, rGO is generally obtained by treating graphene oxide (GO) with hydrazine hydrate, which is a highly hazardous reducing agent. To overcome these problems, herein a novel environmentally-friendly method was developed to assemble 3D printed scaffolds incorporating rGO. Such was achieved through the in situ reduction mediated by l-Ascorbic acid of the GO already present on tricalcium phosphate/gelatin/chitosan scaffolds. The scaffolds functionalized with rGO through the in situ method (TGC_irGO) displayed enhanced wettability and improved mechanical properties without impairing their porosity when compared to their equivalents functionalized with GO and non-functionalized scaffolds (TGC_GO and TGC, respectively). Moreover, the TGC_irGO scaffolds displayed an improved calcium deposition at their surface and an enhanced alkaline phosphatase (ALP) activity, along 21 days of incubation. Additionally, scaffolds also displayed antimicrobial activity without compromising osteoblasts’ viability and proliferation. Such features reveal the potential of the TGC_irGO scaffolds for bone tissue regeneration applications.