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Functionalization of AuMSS nanorods towards more effective cancer therapies

Publication . Rodrigues, Ana Carolina Félix; Jacinto, Telma A.; Moreira, André; Costa, Elisabete C.; Miguel, Sónia P.; Correia, I.J.

The application of nanoparticles as selective drug delivery platforms arises as one the most promising therapeutic strategies in the biomedical field. Such systems can encapsulate drugs, prevent its premature degradation, transport and promote the drugs specific delivery to the target site. Among the different nanostructures, gold-core mesoporous silica shell (AuMSS) nanorods have been one of the most explored due to their unique physical and chemical properties. The mesoporous silica biocompatibility, high surface area that can be easily functionalized, tubular pores that can store the drugs, conjugated with the intrinsic capacity of gold nanorod to absorb near-infrared radiation, allows the combination of hyperthermia (i.e., photothermal effect) with drug delivery, making them a nanoplatforms with a huge potential for cancer therapy. Nevertheless, the successful application of AuMSS nanoparticles as an effective cancer nanomedicine is hindered by the uncontrolled release of the therapeutic payloads, limited blood circulation time and unfavorable pharmacokinetics. In this review, an overview of the modifications performed to improve the AuMSS nanorods application in nanomedicine is provided, highlighting the practical approaches that enhanced the AuMSS nanorods targeting, responsiveness to different stimuli, and blood circulation time. Further, the basics of AuMSS nanorods synthesis procedures, general properties, and its application in cancer therapy are also described.

2019-01-15Journal article

Restricted access

Implications of epigallocatechin-3-gallate in cultured human Sertoli cells glycolytic and oxidative profile

Publication . Dias, Tânia R.; Alves, Marco G; Silva, Joaquina; Barros, Alberto; Sousa, Mário; Casal, Susana; Silva, Branca M.; Oliveira, Pedro F.

Sertoli cells are crucial for the success of spermatogenesis, which is the biological process that ensures male fertility. These cells present high metabolic rates, being often subjected to high oxidative stress levels that, if uncontrolled, may compromise male fertility. Since the most abundant tea catechin, epigallocatechin-3-gallate (EGCG), has demonstrated a potent preventive activity against oxidative stress, we have evaluated its effect at concentrations of 5 and 50μM, on the metabolism, mitochondrial functionality and oxidative profile of human Sertoli cells (hSCs). While, the highest concentration of EGCG (50μM) increased glucose and pyruvate consumption, it decreased the conversion of pyruvate to alanine to sustain a regular lactate production. However, despite maintaining Krebs cycle functionality, EGCG (50μM) decreased mitochondrial membrane potential of hSCs, which could compromise the normal rates of ATP production. Interestingly, oxidative damages to proteins and lipids decreased in this experimental group, which may be valuable for the nutritional support of spermatogenesis.

2017Journal article

Open access

L-Theanine promotes cultured human Sertoli cells proliferation and modulates glucose metabolism

Publication . Dias, T. R.; Bernardino, Raquel; Alves, Marco G; Silva, Joaquina; Barros, Alberto; Sousa, Mário; Casal, Susana; Silva, Branca M.; Oliveira, P.F.

L-Theanine is the major free amino acid present in tea (Camellia sinensis L.). The effects of several tea constituents on male reproduction have been investigated, but L-theanine has been overlooked. Sertoli cells (SCs) are essential for the physical and nutritional support of germ cells. In this study, we aimed to investigate the ability of L-theanine to modulate important mechanisms of human SCs (hSCs) metabolism, mitochondrial function and oxidative profile, which are essential to prevent or counteract spermatogenesis disruption in several health conditions.

2019Journal article

Open access

Bacteriocin production of the probiotic Lactobacillus acidophilus KS400

Publication . Gaspar, C; Donders, Gilbert; Oliveira, Rita Palmeira de; Queiroz, João; Tomaz, C. T.; Oliveira, J. Martinez de; Oliveira, Ana Palmeira de

In the last years, the use of probiotics, including Lactobacillus species, has received much attention to prevent and treat vaginal disorders. These species have been described as having the ability to colonize the epithelial surface and produce antimicrobial metabolites that are able to control the remaining vaginal microflora. This study aimed to identify and characterize, for the first time, a bacteriocin natively produced by Lactobacillus acidophilus KS400 (probiotic strain from Gynoflor®-Medinova AG, Switzerland) and its antimicrobial activity against relevant urogenital pathogens. After organic acids and hydrogen peroxide neutralization in the fermented Lactobacillus acidophilus KS400 culture medium, bacteriocin activity was tested against the indicator microorganism Lactobacillus delbrueckii ATCC9649. The fermentation of Lactobacillus acidophilus KS400 for bacteriocin production was carried out in batch mode, and its antimicrobial activity, optical density and pH were monitored. After production and extraction, the bacteriocin molecular weight was estimated by electrophoresis and tested against vaginal pathogenic microorganisms. As described for other bacteriocins, batch fermentation profiles indicated that bacteriocin production occurs during the exponential growth phase of the lactobacilli, and declines during their stationary growth phase. The molecular weight of the bacteriocin is approximately 7.5 kDa. The bacteriocin containing protein extract was shown to inhibit the growth of Gardnerella vaginalis, Streptococcus agalactiae, Pseudomonas aeruginosa and the indicator strain Lactobacillus delbrueckii ATCC9649. We conclude that L. acidophilus KS400 produces bacteriocin with antimicrobial activity against relevant urogenital pathogens.

2018-09-27Journal article

Open access