Astaxanthin impact on brain: health potential and market perspective.

Nowadays, there is an emergent interest in new trend-driven biomolecules to improve health and wellbeing, which has become an interesting and promising field, considering their high value and biological potential. Astaxanthin is one of these promising biomolecules, with impressive high market growth, especially in the pharmaceutical and food industries. This biomolecule, obtained from natural sources (i.e., microalgae), has been reported in the literature to have several beneficial health effects due to its biological properties. These benefits seem to be mainly associated with Astaxanthin's high antioxidant and anti-inflammatory properties, which may act on several brain issues, thus attenuating symptoms. In this sense, several studies have demonstrated the impact of astaxanthin on a wide range of diseases, namely on brain disorders (such as Alzheimer's disease, Parkinson, depression, brain stroke and autism). Therefore, this review highlights its application in mental health and illness. Furthermore, a S.W.O.T. analysis was performed to display an approach from the market/commercial perspective. However, to bring the molecule to the market, there is still a need for more studies to increase deep knowledge regarding the real impact and mechanisms in the human brain.HIGHLIGHTSAstaxanthin has been mainly extracted from the algae Haematococcus pluvialisAstaxanthin, bioactive molecule with high antioxidant and anti-inflammatory propertiesAstaxanthin has an important protective effect on brain disordersAstaxanthin is highly marketable, mainly for food and pharmaceutical industries.

Tannic Acid Tailored-Made Microsystems for Wound Infection.

Difficult-to-treat infections make complex wounds a problem of great clinical and socio-economic impact. Moreover, model therapies of wound care are increasing antibiotic resistance and becoming a critical problem, beyond healing. Therefore, phytochemicals are promising alternatives, with both antimicrobial and antioxidant activities to heal, strike infection, and the inherent microbial resistance. Hereupon, chitosan (CS)-based microparticles (as CM) were designed and developed as carriers of tannic acid (TA). These CMTA were designed to improve TA stability, bioavailability, and delivery in situ. The CMTA were prepared by spray dryer technique and were characterized regarding encapsulation efficiency, kinetic release, and morphology. Antimicrobial potential was evaluated against methicillin-resistant and methicillin-sensitive Staphylococcus aureus (MRSA and MSSA), Staphylococcus epidermidis, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa strains, as common wound pathogens, and the agar diffusion inhibition growth zones were tested for antimicrobial profile. Biocompatibility tests were performed using human dermal fibroblasts. CMTA had a satisfactory product yield of ca. 32% and high encapsulation efficiency of ca. 99%. Diameters were lower than 10 µm, and the particles showed a spherical morphology. The developed microsystems were also antimicrobial for representative Gram+, Gram-, and yeast as common wound contaminants. CMTA improved cell viability (ca. 73%) and proliferation (ca. 70%) compared to free TA in solution and even compared to the physical mixture of CS and TA in dermal fibroblasts.

Expanding the Potential of Self-Assembled Silk Fibroin as Aerogel Particles for Tissue Regeneration.

A newly produced silk fibroin (SF) aerogel particulate system using a supercritical carbon dioxide (scCO2)-assisted drying technology is herein proposed for biomedical applications. Different concentrations of silk fibroin (3%, 5%, and 7% (w/v)) were explored to investigate the potential of this technology to produce size- and porosity-controlled particles. Laser diffraction, helium pycnometry, nitrogen adsorption-desorption analysis and Fourier Transform Infrared with Attenuated Total Reflectance (FTIR-ATR) spectroscopy were performed to characterize the physicochemical properties of the material. The enzymatic degradation profile of the SF aerogel particles was evaluated by immersion in protease XIV solution, and the biological properties by cell viability and cell proliferation assays. The obtained aerogel particles were mesoporous with high and concentration dependent specific surface area (203-326 m2/g). They displayed significant antioxidant activity and sustained degradation in the presence of protease XIV enzyme. The in vitro assessment using human dermal fibroblasts (HDF) confirm the particles' biocompatibility, as well as the enhancement in cell viability and proliferation.

Exploring Silk Sericin for Diabetic Wounds: An In Situ-Forming Hydrogel to Protect against Oxidative Stress and Improve Tissue Healing and Regeneration.

Chronic wounds are one of the most frequent complications that are associated with diabetes mellitus. The overproduction of reactive oxygen species (ROS) is a key factor in the delayed healing of a chronic wound. In the present work, we develop a novel in situ-forming silk sericin-based hydrogel (SSH) that is produced by a simple methodology using horseradish peroxidase (HRP) crosslinking as an advanced dressing for wound healing. The antioxidant and angiogenic effects were assessed in vitro and in vivo after in situ application using an excisional wound-healing model in a genetically-induced diabetic db/db mice and though the chick embryo choriollantoic membrane (CAM) assay, respectively. Wounds in diabetic db/db mice that were treated with SSH closed with reduced granulation tissue, decreased wound edge distance, and wound thickness, when compared to Tegaderm, a dressing that is commonly used in the clinic. The hydrogel also promoted a deposition of collagen fibers with smaller diameter which may have had a boost effect in re-epithelialization. SSH treatment slightly induced two important endogenous antioxidant defenses, superoxide dismutase and catalase. A CAM assay made it possible to observe that SSH led to an increase in the number of newly formed vessels without inducing an inflammatory reaction. The present hydrogel may result in a multi-purpose technology with angiogenic, antioxidant, and anti-inflammatory properties, while advancing efficient and organized tissue regeneration.

In Situ Forming Silk Sericin-Based Hydrogel: A Novel Wound Healing Biomaterial.

In situ cross-linked hydrogels have the advantage of effectively fulfilling the wound in its shape and depth. Amongst the new generation of natural-based biopolymers being proposed for wound care and skin regeneration, silk sericin is particularly interesting due to its exceptional properties such as biocompatibility, biodegradability, and antioxidant behavior, among others. In this study, a new enzyme-mediated cross-linked hydrogel composed of silk sericin is proposed for the first time. The developed hydrogel cross-linking strategy was performed via horseradish peroxidase, under physiological conditions, and presented gelling kinetics under 3 min, as demonstrated by its rheological behavior. The hydrogels presented a high degree of transparency, mainly due to their amorphous conformation. Degradation studies revealed that the hydrogels were stable in phosphate buffer solution (PBS) (pH 7.4) for 17 days, while in the presence of protease XIV (3.5 U/mg) and under acute and chronic physiological pH values, the stability decreased to 7 and 4 days, respectively. During protease degradation, the present sericin hydrogels demonstrated antioxidant activity. In vitro studies using an L929 fibroblast cell line demonstrated that these hydrogels were noncytotoxic, promoting cell adhesion and massive cell colonization after 7 days of culture, demonstrating that cells maintained their viability and proliferation. In addition, the application of sericin-based hydrogel in an in vivo diabetic wound model validated the feasibility of the in situ methodology and demonstrated a local anti-inflammatory effect, promoting the healing process. This study presents a simple, fast, and practical in situ approach to produce a sericin-based hydrogel able to be applied in low exudative chronic wounds. Moreover, the study herein reported fosters the valorization of a textile industrial by-product by its integration in the biomedical field.

In situ Enabling Approaches for Tissue Regeneration: Current Challenges and New Developments.

In situ tissue regeneration can be defined as the implantation of tissue-specific biomaterials (by itself or in combination with cells and/or biomolecules) at the tissue defect, taking advantage of the surrounding microenvironment as a natural bioreactor. Up to now, the structures used were based on particles or gels. However, with the technological progress, the materials' manipulation and processing has become possible, mimicking the damaged tissue directly at the defect site. This paper presents a comprehensive review of current and advanced in situ strategies for tissue regeneration. Recent advances to put in practice the in situ regeneration concept have been mainly focused on bioinks and bioprinting techniques rather than the combination of different technologies to make the real in situ regeneration. The limitation of conventional approaches (e.g., stem cell recruitment) and their poor ability to mimic native tissue are discussed. Moreover, the way of advanced strategies such as 3D/4D bioprinting and hybrid approaches may contribute to overcome the limitations of conventional strategies are highlighted. Finally, the future trends and main research challenges of in situ enabling approaches are discussed considering in vitro and in vivo evidence.