Pedro M. Castro
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Pedro M. Castro has a total of 50 co-authors. Here are the top co-authors by number of shared publications:
- Bruno Sarmento
Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto Universitário de Ciências da Saúde (IUCS-CESPU), Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
11 shared publications - Manuela Pintado
CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal
11 shared publications - Ana Raquel Madureira
CBQF—Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
8 shared publications - Alessandra Braga Ribeiro
CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal
4 shared publications - Flávia Sousa
University of Groningen Antonius Deusinglaan 1
4 shared publications - Francisca Casanova
CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal
4 shared publications
Latest Publications
- Open Access
- 12 November 2024
- Published by MDPI AG in Applied Sciences
- Vol. 14 (22) , 10416
Modified Cellulose Nanocrystals Encapsulating Cannabigerol: A Step Forward in Controlling Intestinal Inflammatory Disorders
Cannabigerol (CBG) from Cannabis sativa L. is known for its anti-inflammatory, antibacterial, and antioxidant properties, showing potential against intestinal inflammation. However, its lipophilic nature limits its absorption and stability. Researchers have explored cellulose nanocrystals (CNCs) to deliver lipophilic compounds and enhance their biological outcomes. This study investigated the capability of modified CNC with cetyltrimethylammonium bromide (CTAB) to effectively deliver CBG. The encapsulation process’s impact on cytotoxicity, biological activity, and controlled release during digestion was assessed. Results indicated that CNC-CTAB encapsulation significantly reduced CBG’s cytotoxicity on intestinal cells, allowing safer administration of higher doses. The antioxidant and anti-inflammatory properties of the encapsulated CBG were retained, resulting in a decrease in reactive oxygen species and cytokine levels in intestinal cells. Additionally, the system inhibited the growth of the intestinal pathogen Campylobacter jejuni. The study supports using CNC-CTAB as an efficient delivery system to enhance CBG’s potential against intestinal inflammation. Incorporating this system into food matrices could lead to novel functional foods for managing intestinal inflammation.
- 12 November 2024
- Published by MDPI AG in Applied Sciences
- Vol. 14 (22) , 10416
Open AccessModified Cellulose Nanocrystals Encapsulating Cannabigerol: A Step Forward in Controlling Intestinal Inflammatory Disorders
Cannabigerol (CBG) from Cannabis sativa L. is known for its anti-inflammatory, antibacterial, and antioxidant properties, showing potential against intestinal inflammation. However, its lipophilic nature limits its absorption and stability. Researchers have explored cellulose nanocrystals (CNCs) to deliver lipophilic compounds and enhance their biological outcomes. This study investigated the capability of modified CNC with cetyltrimethylammonium bromide (CTAB) to effectively deliver CBG. The encapsulation process’s impact on cytotoxicity, biological activity, and controlled release during digestion was assessed. Results indicated that CNC-CTAB encapsulation significantly reduced CBG’s cytotoxicity on intestinal cells, allowing safer administration of higher doses. The antioxidant and anti-inflammatory properties of the encapsulated CBG were retained, resulting in a decrease in reactive oxygen species and cytokine levels in intestinal cells. Additionally, the system inhibited the growth of the intestinal pathogen Campylobacter jejuni. The study supports using CNC-CTAB as an efficient delivery system to enhance CBG’s potential against intestinal inflammation. Incorporating this system into food matrices could lead to novel functional foods for managing intestinal inflammation.
- Open Access
Bleached Hair as Standard Template to Insight the Performance of Commercial Hair Repair Products
The increasing demand for effective hair care products has highlighted the necessity for rigorous claims substantiation methods, particularly for products that target specific hair types. This is essential because the effectiveness of a product can vary significantly based on the hair’s condition and characteristics. A well-defined bleaching protocol is crucial for creating a standardized method to assess product efficacy, especially for products designed to repair damaged hair. The objective of this study was to create a practical bleaching protocol that mimics real-world consumer experiences, ensuring that hair samples exhibit sufficient damage for testing. This approach allows for a reliable assessment of how well various products can repair hair. The protocol serves as a framework for evaluating hair properties and the specific effects of each product on hair structure. Color, brightness, lightness, morphology, and topography were primarily used to understand the big differences in the hair fiber when treated with two repair benchmark products, K18® and Olaplex®, in relation to the Bleached hair. The devised bleaching protocol proved to be a fitting framework for assessing the properties of hair and the unique characteristics of each tested product within the hair fiber. This protocol offers valuable insights and tools for substantiating consumer claims, with morphological and mechanical methods serving as indispensable tools for recognizing and validating claims related to hair. The addition of K18® and Olaplex® demonstrated an increase in hair brightness (Y) and lightness (L* and a*) in relation to the Bleached samples, which were considered relevant characteristics for consumers. Olaplex®’s water-based nature creates a visible inner sheet, effectively filling empty spaces and improving the disulfide linkage network. This enhancement was corroborated by the increased number of disulfide bonds and evident changes in the FTIR profile. In contrast, K18®, owing to the lipophilic nature of its constituents, resulted in the formation of an external layer above the fiber. The composition of each of the products had a discrete impact on the fiber distribution, which was an outcome relevant to the determination of spreadability by consumers.
Open AccessBleached Hair as Standard Template to Insight the Performance of Commercial Hair Repair Products
The increasing demand for effective hair care products has highlighted the necessity for rigorous claims substantiation methods, particularly for products that target specific hair types. This is essential because the effectiveness of a product can vary significantly based on the hair’s condition and characteristics. A well-defined bleaching protocol is crucial for creating a standardized method to assess product efficacy, especially for products designed to repair damaged hair. The objective of this study was to create a practical bleaching protocol that mimics real-world consumer experiences, ensuring that hair samples exhibit sufficient damage for testing. This approach allows for a reliable assessment of how well various products can repair hair. The protocol serves as a framework for evaluating hair properties and the specific effects of each product on hair structure. Color, brightness, lightness, morphology, and topography were primarily used to understand the big differences in the hair fiber when treated with two repair benchmark products, K18® and Olaplex®, in relation to the Bleached hair. The devised bleaching protocol proved to be a fitting framework for assessing the properties of hair and the unique characteristics of each tested product within the hair fiber. This protocol offers valuable insights and tools for substantiating consumer claims, with morphological and mechanical methods serving as indispensable tools for recognizing and validating claims related to hair. The addition of K18® and Olaplex® demonstrated an increase in hair brightness (Y) and lightness (L* and a*) in relation to the Bleached samples, which were considered relevant characteristics for consumers. Olaplex®’s water-based nature creates a visible inner sheet, effectively filling empty spaces and improving the disulfide linkage network. This enhancement was corroborated by the increased number of disulfide bonds and evident changes in the FTIR profile. In contrast, K18®, owing to the lipophilic nature of its constituents, resulted in the formation of an external layer above the fiber. The composition of each of the products had a discrete impact on the fiber distribution, which was an outcome relevant to the determination of spreadability by consumers.
- Open Access
- 17 December 2023
- Published by MDPI AG in Pharmaceuticals
- Vol. 16 (12) , 1737
Biological Potential and Bioaccessibility of Encapsulated Curcumin into Cetyltrimethylammonium Bromide Modified Cellulose Nanocrystals
Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.
- 17 December 2023
- Published by MDPI AG in Pharmaceuticals
- Vol. 16 (12) , 1737
Open AccessBiological Potential and Bioaccessibility of Encapsulated Curcumin into Cetyltrimethylammonium Bromide Modified Cellulose Nanocrystals
Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.
- Open Access
- 26 October 2023
- Published by MDPI AG in Sustainability
- Vol. 15 (21) , 15323
Potential Industrial Synergies in the Steelmaking and Metal-Processing Industry: By-Products Valorization and Associated Technological Processes
Steelmaking and ferrous metal processing companies are suppliers of great importance to a wide array of industries, thus being quintessential for the social and financial growth of regions and countries. Most used processes (i.e., blast furnace, basic oxygen furnace, and electric arc furnace-based) are, however, highly pollutant, generating hazardous wastes that were usually landfilled. Generated wastes are important sources of secondary raw materials such as zinc and iron, presenting interesting market value. Hence, aiming to develop green procedures, industries have been using diverse approaches to treat and detoxify hazardous wastes, extract and reuse added value components, or even use their existing infrastructures to convert the wastes generated by other industries into secondary raw materials for steel manufacturing. This paper reviews the main industrial processes, focusing on the waste-generating steps, and discloses the most recent and relevant industrial synergies toward a circular economy. The final contribution of this study consists of the compilation of industrial synergies and recovery technologies for the steelmaking and metal processes.
- 26 October 2023
- Published by MDPI AG in Sustainability
- Vol. 15 (21) , 15323
Open AccessPotential Industrial Synergies in the Steelmaking and Metal-Processing Industry: By-Products Valorization and Associated Technological Processes
Steelmaking and ferrous metal processing companies are suppliers of great importance to a wide array of industries, thus being quintessential for the social and financial growth of regions and countries. Most used processes (i.e., blast furnace, basic oxygen furnace, and electric arc furnace-based) are, however, highly pollutant, generating hazardous wastes that were usually landfilled. Generated wastes are important sources of secondary raw materials such as zinc and iron, presenting interesting market value. Hence, aiming to develop green procedures, industries have been using diverse approaches to treat and detoxify hazardous wastes, extract and reuse added value components, or even use their existing infrastructures to convert the wastes generated by other industries into secondary raw materials for steel manufacturing. This paper reviews the main industrial processes, focusing on the waste-generating steps, and discloses the most recent and relevant industrial synergies toward a circular economy. The final contribution of this study consists of the compilation of industrial synergies and recovery technologies for the steelmaking and metal processes.
- Open Access
- 18 March 2023
- Published by MDPI AG in Pharmaceutics
- Vol. 15 (3) , 981
Design of Innovative Biocompatible Cellulose Nanostructures for the Delivery and Sustained Release of Curcumin
Poor aqueous solubility, stability and bioavailability of interesting bioactive compounds is a challenge in the development of bioactive formulations. Cellulose nanostructures are promising and sustainable carriers with unique features that may be used in enabling delivery strategies. In this work, cellulose nanocrystals (CNC) and cellulose nanofibers were investigated as carriers for the delivery of curcumin, a model liposoluble compound. Nanocellulose modification with the surfactant cetyltrimethylammonium bromide (CTAB), tannic acid and decylamine (TADA), and by TEMPO-mediated oxidation were also tested and compared. The carrier materials were characterized in terms of structural properties and surface charge, while the delivery systems were evaluated for their encapsulation and release properties. The release profile was assessed in conditions that mimic the gastric and intestinal fluids, and cytotoxicity studies were performed in intestinal cells to confirm safe application. Modification with CTAB and TADA resulted in high curcumin encapsulation efficiencies of 90 and 99%, respectively. While no curcumin was released from TADA-modified nanocellulose in simulated gastrointestinal conditions, CNC-CTAB allowed for a curcumin-sustained release of ca. 50% over 8 h. Furthermore, the CNC-CTAB delivery system showed no cytotoxic effects on Caco-2 intestinal cells up to 0.125 g/L, meaning that up to this concentration the system is safe to use. Overall, the use of the delivery systems allowed for the reduction in the cytotoxicity associated with higher curcumin concentrations, highlighting the potential of nanocellulose encapsulation systems.
- 18 March 2023
- Published by MDPI AG in Pharmaceutics
- Vol. 15 (3) , 981
Open AccessDesign of Innovative Biocompatible Cellulose Nanostructures for the Delivery and Sustained Release of Curcumin
Poor aqueous solubility, stability and bioavailability of interesting bioactive compounds is a challenge in the development of bioactive formulations. Cellulose nanostructures are promising and sustainable carriers with unique features that may be used in enabling delivery strategies. In this work, cellulose nanocrystals (CNC) and cellulose nanofibers were investigated as carriers for the delivery of curcumin, a model liposoluble compound. Nanocellulose modification with the surfactant cetyltrimethylammonium bromide (CTAB), tannic acid and decylamine (TADA), and by TEMPO-mediated oxidation were also tested and compared. The carrier materials were characterized in terms of structural properties and surface charge, while the delivery systems were evaluated for their encapsulation and release properties. The release profile was assessed in conditions that mimic the gastric and intestinal fluids, and cytotoxicity studies were performed in intestinal cells to confirm safe application. Modification with CTAB and TADA resulted in high curcumin encapsulation efficiencies of 90 and 99%, respectively. While no curcumin was released from TADA-modified nanocellulose in simulated gastrointestinal conditions, CNC-CTAB allowed for a curcumin-sustained release of ca. 50% over 8 h. Furthermore, the CNC-CTAB delivery system showed no cytotoxic effects on Caco-2 intestinal cells up to 0.125 g/L, meaning that up to this concentration the system is safe to use. Overall, the use of the delivery systems allowed for the reduction in the cytotoxicity associated with higher curcumin concentrations, highlighting the potential of nanocellulose encapsulation systems.
- 1 September 2019
- Published by Elsevier in Colloids and Surfaces B: Biointerfaces
- Vol. 181, 149-157
Film-nanoparticle composite for enhanced oral delivery of alpha-casozepine
- 1 September 2019
- Published by Elsevier in Colloids and Surfaces B: Biointerfaces
- Vol. 181, 149-157
Film-nanoparticle composite for enhanced oral delivery of alpha-casozepine
- Open Access
- 20 February 2019
- Published by MDPI AG in Pharmaceuticals
- Vol. 12 (1) , 32
Development and Characterization of Chitosan Microparticles-in-Films for Buccal Delivery of Bioactive Peptides
Nowadays, bioactive peptides are used for therapeutic applications and the selection of a carrier to deliver them is very important to increase the efficiency, absorption, release, bioavailability and consumer acceptance. The aim of this study was to develop and characterize chitosan-based films loaded with chitosan microparticles containing a bioactive peptide (sequence: KGYGGVSLPEW) with antihypertensive properties. Films were prepared by the solvent casting method, while the microparticles were prepared by ionic gelation. The final optimized chitosan microparticles exhibited a mean diameter of 2.5 µm, a polydispersity index of 0.46, a zeta potential of +61 mV and a peptide association efficiency of 76%. Chitosan films were optimized achieving the final formulation of 0.79% (w/v) of chitosan, 6.74% (w/v) of sorbitol and 0.82% (w/v) of citric acid. These thin (±0.100 mm) and transparent films demonstrated good performance in terms of mechanical and biological properties. The oral films developed were flexible, elastic, easy to handle and exhibited rapid disintegration (30 s) and an erosion behavior of 20% when they came into contact with saliva solution. The cell viability (75–99%) was proved by methylthiazolydiphenyl-tetrazolium bromide (MTT) assay with TR146 cells. The chitosan mucoadhesive films loaded with peptide–chitosan microparticles resulted in an innovative approach to perform administration across the buccal mucosa, because these films present a larger surface area, leading to the rapid disintegration and release of the antihypertensive peptide under controlled conditions in the buccal cavity, thus promoting bioavailability.
- 20 February 2019
- Published by MDPI AG in Pharmaceuticals
- Vol. 12 (1) , 32
Open AccessDevelopment and Characterization of Chitosan Microparticles-in-Films for Buccal Delivery of Bioactive Peptides
Nowadays, bioactive peptides are used for therapeutic applications and the selection of a carrier to deliver them is very important to increase the efficiency, absorption, release, bioavailability and consumer acceptance. The aim of this study was to develop and characterize chitosan-based films loaded with chitosan microparticles containing a bioactive peptide (sequence: KGYGGVSLPEW) with antihypertensive properties. Films were prepared by the solvent casting method, while the microparticles were prepared by ionic gelation. The final optimized chitosan microparticles exhibited a mean diameter of 2.5 µm, a polydispersity index of 0.46, a zeta potential of +61 mV and a peptide association efficiency of 76%. Chitosan films were optimized achieving the final formulation of 0.79% (w/v) of chitosan, 6.74% (w/v) of sorbitol and 0.82% (w/v) of citric acid. These thin (±0.100 mm) and transparent films demonstrated good performance in terms of mechanical and biological properties. The oral films developed were flexible, elastic, easy to handle and exhibited rapid disintegration (30 s) and an erosion behavior of 20% when they came into contact with saliva solution. The cell viability (75–99%) was proved by methylthiazolydiphenyl-tetrazolium bromide (MTT) assay with TR146 cells. The chitosan mucoadhesive films loaded with peptide–chitosan microparticles resulted in an innovative approach to perform administration across the buccal mucosa, because these films present a larger surface area, leading to the rapid disintegration and release of the antihypertensive peptide under controlled conditions in the buccal cavity, thus promoting bioavailability.
- 1 August 2018
- Published by Elsevier in International Journal of Pharmaceutics
- Vol. 547 (1-2) , 593-601
Combination of PLGA nanoparticles with mucoadhesive guar-gum films for buccal delivery of antihypertensive peptide
- 1 August 2018
- Published by Elsevier in International Journal of Pharmaceutics
- Vol. 547 (1-2) , 593-601
Combination of PLGA nanoparticles with mucoadhesive guar-gum films for buccal delivery of antihypertensive peptide
- Open Access
- 1 August 2018
- Published by Elsevier in Carbohydrate Polymers
- Vol. 194, 411-421
Incorporation of beads into oral films for buccal and oral delivery of bioactive molecules
- 1 August 2018
- Published by Elsevier in Carbohydrate Polymers
- Vol. 194, 411-421
Open AccessIncorporation of beads into oral films for buccal and oral delivery of bioactive molecules
- 1 July 2018
- Published by Elsevier in European Polymer Journal
- Vol. 104, 19-31
Bioadhesive polymeric nanoparticles as strategy to improve the treatment of yeast infections in oral cavity: in-vitro and ex-vivo studies
- 1 July 2018
- Published by Elsevier in European Polymer Journal
- Vol. 104, 19-31
Bioadhesive polymeric nanoparticles as strategy to improve the treatment of yeast infections in oral cavity: in-vitro and ex-vivo studies