Browsing by Author "Amaral, Maria Helena"
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- Acne vulgaris topical therapies: application of probiotics as a new prevention strategyPublication . Dapkevicius, Ieva; Romualdo, Vânia; Marques, Ana Camila; Lopes, Carla Martins; Amaral, Maria HelenaThe skin microbiome is an essential barrier for preventing the invasion of pathogens and regulating the immune responses. When this barrier is disrupted, several dermatoses, including acne vulgaris, may arise. Most people will experience acne starting at the onset of puberty and continuing into adolescence; a significant percentage of those individuals continue to suffer from it into adulthood. Although common, this dermatosis usually has an enormous impact on the self-esteem and quality of life of individuals who suffer from it. An increase in consumer literacy regarding skincare leads buyers to seek out innovative products containing ingredients with proven benefits for their concerns. Probiotics have proven to be an alternative to the use of antibiotics, often associated with undesirable effects, in the treatment and prevention of dermatological disorders such as acne. This review provides a comprehensive analysis of the pathophysiology, risk factors, symptoms, conventional treatment recommendations and main studies emphasizing innovative topical products for acne-prone skin based on probiotics. In addition, the potential advantages, and limitations/challenges associated with the implementation and manufacturing of these innovative skin products are also highlighted.
- Applications of polymeric and lipid nanoparticles in ophthalmic pharmaceutical formulations: present and future considerationsPublication . Almeida, Hugo; Amaral, Maria Helena; Lobão, Paulo; Silva, Ana Catarina; Lobo, José Manuel SousaThe unique properties and characteristics of ocular tissues and the whole set of defence mechanisms of the ocular globe make the instillation of ocular drugs into a difficult task with a low rate of therapeutic response. One of the challenges for the new generation of ophthalmic pharmaceutical formulations is to increase the bioavailability of drugs administered by the ocular route and, therefore, their therapeutic efficacy. This can be achieved with the use of some strategies that provide an increase in the formulation pre-corneal residence time, mucoadhesion and penetration across the eye tissues. Colloidal carrier systems have been very successfully used for the selective and targeted delivery of drugs for several routes of administration. In this context, nanoparticles prepared with specific polymers or lipids and coated, dispersed or suspended in polymer solutions with mucoadhesion properties or in situ gelling properties will be an excellent strategy that deserves attention and further research. In this review, the characteristics and main properties of polymeric and lipid nanoparticles are discussed and examples and advantages of the application of these colloidal carrier systems for the ophthalmic administration of drugs are presented. The future directions of the research required in this specific field are also presented.
- Biotechnology applied to cosmetics and aesthetic medicinesPublication . Gomes, Cátia; Silva, Ana Catarina; Marques, Ana Camila; Sousa Lobo, José; Amaral, Maria HelenaBiotechnology uses microorganisms and/or enzymes to obtain specific products through fermentative processes and/or genetic engineering techniques. Examples of these products are active ingredients, such as hyaluronic acid, kojic acid, resveratrol, and some enzymes, which are used in skin anti-aging products. In addition, certain growth factors, algae, stem cells, and peptides have been included in cosmetics and aesthetic medicines. Thus, biotechnology, cosmetics and aesthetic medicines are now closely linked, through the production of high-quality active ingredients, which are more effective and safer. This work describes the most used active ingredients that are produced from biotechnological processes. Although there are a vast number of active ingredients, the number of biotechnological active ingredients reported in the literature is not significantly high.
- Design, characterization, and clinical evaluation of argan oil nanostructured lipid carriers to improve skin hydrationPublication . Tichota, Deise Michele; Silva, Ana Catarina; Lobo, José Manuel Sousa; Amaral, Maria HelenaGiven its advantages in skin application (eg, hydration, antiaging, and protection), argan oil could be used in both dermatological and cosmetic formulations. Therefore, the preparation of nanostructured lipid carriers (NLCs) using argan oil as a liquid lipid is a promising technique, since the former constitute well-established systems for dermal delivery. The aim of this work was to develop a topical formulation of argan oil NLCs to improve skin hydration. Firstly an NLC dispersion was developed and characterized, and afterward an NLC-based hydrogel was prepared. The in vivo evaluation of the suitability of the prepared formulation for the proposed application was assessed in volunteers, by measuring different skin-surface parameters for 1 month. An argan oil NLC-based hydrogel formulation was successfully prepared and characterized. Moreover, the entrapment of the NLCs in the hydrogel net did not affect their colloidal sizes. Additionally, it was observed that this formulation precipitated an increase in skin hydration of healthy volunteers. Therefore, we concluded that the preparation of NLC systems using argan oil as the liquid lipid is a promising strategy, since a synergistic effect on the skin hydration was obtained (ie, NLC occlusion plus argan oil hydration).
- Development of an HPLC method for the quantification of riluzolePublication . Teixeira, Maria Inês; Lopes, Carla Martins; Amaral, Maria Helena; Costa, Paulo
- Editorial: applications of Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC): state of the artPublication . Silva, Ana Catarina; Amaral, Maria Helena; Lobo, José Manuel Sousa; Almeida, Hugo
- Formulation, characterization, and cytotoxicity evaluation of lactoferrin functionalized lipid nanoparticles for riluzole delivery to the brainPublication . Teixeira, Maria Inês; Lopes, Carla Martins; Gonçalves, Hugo; Catita, José; Silva, Ana Margarida; Rodrigues, Francisca; Amaral, Maria Helena; Costa, Paulo C.Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a very poor prognosis. Its treatment is hindered by a lack of new therapeutic alternatives and the existence of the blood–brain barrier (BBB), which restricts the access of drugs commonly used in ALS, such as riluzole, to the brain. To overcome these limitations and increase brain targeting, riluzole-loaded nanostructured lipid carriers (NLC) were prepared and functionalized with lactoferrin (Lf), facilitating transport across the BBB by interacting with Lf receptors expressed in the brain endothelium. NLC were characterized with respect to their physicochemical properties (size, zeta potential, polydispersity index) as well as their stability, encapsulation efficiency, morphology, in vitro release profile, and biocompatibility. Moreover, crystallinity and melting behavior were assessed by DSC and PXRD. Nanoparticles exhibited initial mean diameters between 180 and 220 nm and a polydispersity index below 0.3, indicating a narrow size distribution. NLC remained stable over at least 3 months. Riluzole encapsulation efficiency was very high, around 94–98%. FTIR and protein quantification studies confirmed the conjugation of Lf on the surface of the nanocarriers, with TEM images showing that the functionalized NLC presented a smooth surface and uniform spherical shape. An MTT assay revealed that the nanocarriers developed in this study did not cause a substantial reduction in the viability of NSC-34 and hCMEC/D3 cells at a riluzole concentration up to 10 μM, being therefore biocompatible. The results suggest that Lf-functionalized NLC are a suitable and promising delivery system to target riluzole to the brain.
- Lactoferrin functionalized NLC for Amyotrophic Lateral SclerosisPublication . Teixeira, Maria Inês; Lopes, Carla Martins; Amaral, Maria Helena; Costa, Paulo
- Permeability assay and inflammatory marker quantification of lactoferrin functionalized lipid nanoparticles intended for brain deliveryPublication . Teixeira, Maria Inês; Lopes, Carla Martins; Reguengo, Henrique; Oliveira, José Carlos; Silva, Ana Margarida; Rodrigues, Francisca; Amaral, Maria Helena; Costa, Paulo C.Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a survival rate of 3 to 5 years from the onset of symptoms. ALS treatment is compromised by the existence of the blood-brain barrier (BBB), which restricts the access of promising biopharmaceutics to the brain, including riluzole, a drug commonly used to treat ALS. To circumvent the BBB and improve the drug brain targeting, nanosystems such as lipid nanoparticles can be employed. In this work, the permeation of nanostructured lipid carriers (NLC) loaded with riluzole and functionalized with a specific ligand – lactoferrin – was assessed in an in vitro BBB model (hCMEC/D3 cell line). Moreover, the effect of the NLC on the production and secretion of the pro-inflammatory cytokine human interleukin 1 alpha (IL-1a) by the cells was also quantified. The permeability studies across the hCMEC/D3 cell monolayers showed that free riluzole penetrated the BBB more than the riluzole-loaded NLC, which was also consistent with the results from the ELISA kit, with the free drug eliciting a higher IL-1a production. Despite these findings, the developed nanocarriers possessed good biocompatibility and stability, and could, therefore, be considered suitable for brain applications.
- Recent developments in microfluidic technologies for central nervous system targeted studiesPublication . Teixeira, Maria Inês; Amaral, Maria Helena; Costa, Paulo; Lopes, Carla Martins; Lamprou, Dimitrios A.Neurodegenerative diseases (NDs) bear a lot of weight in public health. By studying the properties of the blood-brain barrier (BBB) and its fundamental interactions with the central nervous system (CNS), it is possible to improve the understanding of the pathological mechanisms behind these disorders and create new and better strategies to improve bioavailability and therapeutic efficiency, such as nanocarriers. Microfluidics is an intersectional field with many applications. Microfluidic systems can be an invaluable tool to accurately simulate the BBB microenvironment, as well as develop, in a reproducible manner, drug delivery systems with well-defined physicochemical characteristics. This review provides an overview of the most recent advances on microfluidic devices for CNS-targeted studies. Firstly, the importance of the BBB will be addressed, and different experimental BBB models will be briefly discussed. Subsequently, microfluidic-integrated BBB models (BBB/brain-on-a-chip) are introduced and the state of the art reviewed, with special emphasis on their use to study NDs. Additionally, the microfluidic preparation of nanocarriers and other compounds for CNS delivery has been covered. The last section focuses on current challenges and future perspectives of microfluidic experimentation.