Débora Ferreira

Novel cosmetic formulations containing a biosurfactant from Lactobacillus paracasei

Cosmetic and personal care products including toothpaste, shampoo, creams, makeup, among others, are usually formulated with petroleum-based surfactants, although in the last years the consume trend for green products is inducing the replacement of surface-active agents in these formulations by natural surfactants, so-called biosurfactants. In addition to their surfactant capacity, many biosurfactants can act as good emulsifiers, which is an extra advantage in the preparation of green cosmetic products. In this work, a biosurfactant obtained from Lactobacillus paracasei was used as a stabilizing agent in oil-in-water emulsions containing essential oils and natural antioxidant extract. In the presence of biosurfactant, maximum percentages of emulsion volumes (EV=100%) were observed, with droplets sizes about 199nm. These results were comparable with the ones obtained using sodium dodecyl sulfate (SDS), a synthetic well known surfactant with high emulsify capacity. Moreover, the biosurfactant and emulsions cytotoxicity was evaluated using a mouse fibroblast cell line. Solutions containing 5g/L of biosurfactant presented cell proliferation values of 97%, whereas 0.5g/L of SDS showed a strong inhibitory effect. Overall, the results herein gathered are very promising towards the development of new green cosmetic formulations.

Bioactivity of glycolipopeptide cell-bound biosurfactants against skin pathogens

The antimicrobial and anti-adhesive activities of the cell-bound biosurfactants, produced by Lactobacillus pentosus (PEB), characterized as glycolipopeptide macromolecules, were evaluated against several microorganisms present in the skin microflora, envisaging its potential use as a natural ingredient in cosmetic and personal care formulations. Their performance was compared with another cell-bound biosurfactants also characterized as glycolipopeptides produced by Lactobacillus paracasei (PAB). At concentrations of 50mg/mL, the PEB showed an important antimicrobial activity against Pseudomonas aeruginosa (85% when extracted with phosphate buffer (PB) and 100% when extracted with phosphate buffer saline (PBS)), Streptococcus agalactiae (100% for both extracts), Staphylococcus aureus (67% when extracted with PBS and 100% when extracted with PB), Escherichia coli (72% when extracted with PB and 89% when extracted with PBS), Streptococcus pyogenes (about 85% for both extracts) and Candida albicans (around 70% for both extracts), comparable with that obtained for the PAB. However, at lower concentrations the PAB exhibited in general higher antimicrobial activities. Biosurfactants produced by both microorganisms also showed significant anti-adhesive properties against all the microorganisms under study, except for E. coli and C. albicans (less than 30%). Overall, these cell-bound biosurfactants could be used as potential antimicrobial and anti-adhesive agents in cosmetic and pharmaceutical formulations.

Synthetic biology strategies towards the development of new bioinspired technologies for medical applications

Abstract Synthetic biology in combination with systems biology uses engineering principles to leverage the power of biology. The impact and potential of systems and synthetic biology in the prevention, diagnosis and treatment of diseases are growing. In this chapter, we will revise some of the tools, methods and applications within these fields that can be useful in biomedical engineering and human health, such as genome editing and the development of quorum sensing mechanisms, among others. We will discuss remarkable advances made, for example, in vaccine development, diagnosis and treatment of cancer and infectious diseases, microbiome engineering and cell therapy. Lastly, the challenges and perspectives of these fields will be debated.

Screening and characterization of novel specific peptides targeting MDA-MB-231 claudin-low breast carcinoma by computer-aided phage display methodologies

BackgroundClaudin-low breast carcinoma represents 19% of all breast cancer cases and is characterized by an aggressive progression with metastatic nature and high rates of relapse. Due to a lack of known specific molecular biomarkers for this breast cancer subtype, there are no targeted therapies available, which results in the worst prognosis of all breast cancer subtypes. Hence, the identification of novel biomarkers for this type of breast cancer is highly relevant for an early diagnosis. Additionally, claudin-low breast carcinoma peptide ligands can be used to design powerful drug delivery systems that specifically target this type of breast cancer.MethodsIn this work, we propose the identification of peptides for the specific recognition of MDA-MB-231, a cell line representative of claudin-low breast cancers, using phage display (both conventional panning and BRASIL). Binding assays, such as phage forming units and ELISA, were performed to select the most interesting peptides (i.e., specific to the target cells) and bioinformatics approaches were applied to putatively identify the biomarkers to which these peptides bind.ResultsTwo peptides were selected using this methodology specifically targeting MDA-MB-231 cells, as demonstrated by a 4 to 9 log higher affinity as compared to control cells. The use of bioinformatics approaches provided relevant insights into possible cell surface targets for each peptide identified.ConclusionsThe peptides herein identified may contribute to an earlier detection of claudin-low breast carcinomas and possibly to develop more individualized therapies.

Artificial virus particles

This chapter intends to provide an overview of the use of viruses for medical applications. The first part describes the basic characteristics of viral particles regarding their chemical composition and size, as well as their structure and assembly/disassembly abilities. Next, a discussion about the newest and most important strategies for virus particles modification including genetic, chemical, and self-assembly/encapsulation engineering towards the development of new virus particles for biomedical applications, including targeted delivery and therapy, molecular imaging for disease detection, vaccine development, and bacterial infection control.

Spectra optical detection of biomolecules using a white light source-based spectrophotometric platform

This work describes the integration of thin-film optical filters in a lab-on-a-chip device for spectrophotometric analysis of biological fluids using white-light as illumination. Thin-film SiO2/TiO2 multilayers were optimized according to numerical simulations, so that the optical transmittance is tuned for specific wavelengths. These films were deposited on glass substrates by Ion Beam and then integrated in a previously developed lab-on-a-chip platform, which incorporates microfluidic and detection modules. The system operates with a white-light source that is filtered to a narrow spectral band, centred at the desired wavelength, allowing the selective measurement of the light intensity transmitted through the fluid. This intensity is quantified using a colorimetric detection system and then correlated with the biomolecule concentration. Several calcium concentrations in urine were successfully detected in the lab-on-a-chip using the filtering system.