Development of layer-by-layer polymeric microneedles for localized delivery of therapeutics to cervical cancer

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Influence of ClearT and ClearT2 Agitation Conditions in the Fluorescence Imaging of 3D Spheroids

Publication . Silva, Daniel N.; Costa, Elisabete; Rodrigues, Ana Carolina Félix; Diogo, Duarte de Melo; Correia, I.J.; Moreira, André F.

3D tumor spheroids have arisen in the last years as potent tools for the in vitro screening of novel anticancer therapeutics. Nevertheless, to increase the reproducibility and predictability of the data originated from the spheroids it is still necessary to develop or optimize the techniques used for spheroids' physical and biomolecular characterization. Fluorescence microscopy, such as confocal laser scanning microscopy (CLSM), is a tool commonly used by researchers to characterize spheroids structure and the antitumoral effect of novel therapeutics. However, its application in spheroids' analysis is hindered by the limited light penetration in thick samples. For this purpose, optical clearing solutions have been explored to increase the spheroids' transparency by reducing the light scattering. In this study, the influence of agitation conditions (i.e., static, horizontal agitation, and rotatory agitation) on the ClearT and ClearT2 methods' clearing efficacy and tumor spheroids' imaging by CLSM was characterized. The obtained results demonstrate that the ClearT method results in the improved imaging of the spheroids interior, whereas the ClearT2 resulted in an increased propidium iodide mean fluorescence intensity as well as a higher signal depth in the Z-axis. Additionally, for both methods, the best clearing results were obtained for the spheroids treated under the rotatory agitation. In general, this work provides new insights on the ClearT and ClearT2 clearing methodologies and their utilization for improving the reproducibility of the data obtained through the CLSM, such as the analysis of the cell death in response to therapeutics administration.

2020-12-29Journal article

Open access

Development of gold-core silica shell nanospheres coated with poly-2-ethyl-oxazoline and β-cyclodextrin aimed for cancer therapy

Publication . 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.

2019-01-16Journal article

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Strategies to Improve Cancer Photothermal Therapy Mediated by Nanomaterials

Publication . Diogo, Duarte Miguel de Melo; Silva, Cleide Isabel Pais; Dias, Diana Rodrigues; Moreira, André; Correia, Ilídio Joaquim Sobreira

The deployment of hyperthermia‐based treatments for cancer therapy has captured the attention of different researchers worldwide. In particular, the application of light‐responsive nanomaterials to mediate hyperthermia has revealed promising results in several pre‐clinical assays. Unlike conventional therapies, these nanostructures can display a preferential tumor accumulation and thus mediate, upon irradiation with near‐infrared light, a selective hyperthermic effect with temporal resolution. Different types of nanomaterials such as those based on gold, carbon, copper, molybdenum, tungsten, iron, palladium and conjugated polymers have been used for this photothermal modality. This progress report summarizes the different strategies that have been applied so far for increasing the efficacy of the photothermal therapeutic effect mediated by nanomaterials, namely those that improve the accumulation of nanomaterials in tumors (e.g. by changing the corona composition or through the functionalization with targeting ligands), increase nanomaterials' intrinsic capacity to generate photoinduced heat (e.g. by synthesizing new nanomaterials or assembling nanostructures) or by optimizing the parameters related to the laser light used in the irradiation process (e.g. by modulating the radiation wavelength). Overall, the development of new strategies or the optimization and combination of the existing ones will surely give a major contribution for the application of nanomaterials in cancer PTT.

2017-03-21Journal article

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Development of a poly(vinyl alcohol)/lysine electrospun membrane-based drug delivery system for improved skin regeneration

Publication . Sequeira, Rosa Maria Saraiva; Miguel, Sónia; Cabral, Cátia S. D.; Moreira, André; Ferreira, Paula; Correia, I.J.

Nanofiber-based wound dressings are currently being explored as delivery systems of different biomolecules for avoiding skin infections as well as improve/accelerate the healing process. In the present work, a nanofibrous membrane composed of poly(vinyl alcohol) (PVA) and lysine (Lys) was produced by using the electrospinning technique. Further, anti-inflammatory (ibuprofen (IBP)) and antibacterial (lavender oil (LO)) agents were incorporated within the electrospun membrane through blend electrospinning and surface physical adsorption methods, respectively. The obtained results demonstrated that the PVA_Lys electrospun membranes incorporating IBP or LO displayed the suitable morphological, mechanical and biological properties for enhancing the wound healing process. Moreover, the controlled and sustained release profile attained for IBP was appropriate for the duration of the wound healing inflammatory phase, whereas the initial burst release of LO is crucial to prevent wound bacterial contamination. Indeed, the PVA_Lys_LO electrospun membranes were able to mediate a strong antibacterial activity against both S. aureus and P. aeruginosa, without compromising human fibroblasts viability. Overall, the gathered data emphasizes the potential of the PVA_Lys electrospun membranes-based drug delivery systems to be used as wound dressings.

2019Journal article

Open access

3D tumor spheroids: an overview on the tools and techniques used for their analysis

Publication . Costa, Elisabete C.; Moreira, André; Diogo, Duarte Miguel de Melo; Gaspar, V. M.; Carvalho, Marco António Paulo de; Correia, I.J.

In comparison with 2D cell culture models, 3D spheroids are able to accurately mimic some features of solid tumors, such as their spatial architecture, physiological responses, secretion of soluble mediators, gene expression patterns and drug resistance mechanisms. These unique characteristics highlight the potential of 3D cellular aggregates to be used as in vitro models for screening new anticancer therapeutics, both at a small and large scale. Nevertheless, few reports have focused on describing the tools and techniques currently available to extract significant biological data from these models. Such information will be fundamental to drug and therapeutic discovery process using 3D cell culture models. The present review provides an overview of the techniques that can be employed to characterize and evaluate the efficacy of anticancer therapeutics in 3D tumor spheroids.

2016-11-11Journal article

Restricted access