Search

A simple screening methodology was employed to correlate the structures of hydroxycinnamic acids (HCAs) and their esterified derivatives with their in vitro antifungal activity overThe online version contains supplementary material available at 10.1007/s13205-022-03425-7.

Oligodendrocyte precursor cell (OPC) migration is a mechanism involved in remyelination, these cells migrate from niches in the adult CNS. However, age and disease reduce the pool of OPCs, as a result, the remyelination capacity of the CNS decreases over time. Several experimental studies have introduced OPCs to the brain via direct injection or intrathecal administration. In this study, we used the nose-to brain pathway to deliver oligodendrocyte lineage cells (human oligodendroglioma (HOG) cells), which behave similarly to OPCs in vitro. To this end, we administered GFP-labelled HOG cells intranasally to experimental animals, which were subsequently euthanised at 30 or 60 days. Our results show that the intranasal route is a viable route to the CNS and that HOG cells administered intranasally migrate preferentially to niches of OPCs (clusters created during embryonic development and adult life). Our study provides evidence, albeit limited, that HOG cells either form clusters or adhere to clusters of OPCs in the brains of experimental animals.

Over the past thirty years, research has shown the huge potential of chitosan in biomedical applications such as drug delivery, tissue engineering and regeneration, cancer therapy, and antimicrobial treatments, among others. One of the major advantages of this interesting polysaccharide is its modifiability, which facilitates its use in tailor-made applications. In this way, the molecular structure of chitosan has been conjugated with multiple molecules to modify its mechanical, biological, or chemical properties. Here, we review the conjugation of chitosan with some bioactive molecules: hydroxycinnamic acids (HCAs); since these derivatives have been probed to enhance some of the biological effects of chitosan and to fine-tune its characteristics for its application in the biomedical field. First, the main characteristics of chitosan and HCAs are presented; then, the currently employed conjugation strategies between chitosan and HCAs are described; and, finally, the studied biomedical applications of these derivatives are discussed to present their limitations and advantages, which could lead to proximal therapeutic uses.

Current efforts to find novel treatments that counteract multiple sclerosis (MS) have pointed toward immunomodulation and remyelination. Currently, cell therapy has shown promising potential to achieve this purpose. However, disadvantages such as poor survival, differentiation, and integration into the target tissue have limited its application. A series of recent studies have focused on the cell secretome, showing it to provide the most benefits of cell therapy. Exosomes are a key component of the cell secretome, participating in the transfer of bioactive molecules. These nano-sized vesicles offer many therapeutical advantages, such as the capacity to cross the blood-brain barrier, an enrichable cargo, and a customizable membrane. Moreover, integrating of biomaterials into exosome therapy could lead to new tissue-specific therapeutic strategies. In this work, the use of exosomes and their integration with biomaterials is presented as a novel strategy in the treatment of MS.

Nowadays it is known that neural cells are capable of regenerating after brain injury, but their success highly depends on the local environment, including the presence of a biological structure to support cell proliferation and restore the lost tissue. Different chitosan-based biomaterials have been employed in response to this necessity. We hypothesized that hydrogels made of antioxidant compounds functionalizing chitosan could provide a suitable environment to home new cells and offer a way to achieve brain repair. In this work, the implantation of functionalized chitosan biomaterials in a brain injury animal model was evaluated. The injury consisted of mechanical damage applied to the cerebral cortex of Wistar rats followed by the implantation of four different chitosan-based biomaterials. After 15 and 30 days, animals underwent magnetic resonance imaging, then they were sacrificed, and the brain tissue was analyzed by immunohistochemistry. The proliferation of microglia and astrocytes increased at the lesion zone, showing differences between the evaluated biomaterials. Also, cell nuclei were seen inside the biomaterials, indicating cell migration and biodegradation. Chitosan-based hydrogels are able to fill in the tissue cavity and bare cells for the endogenous restoration process. The addition of ferulic and succinic acid to the chitosan structure increases this capacity and decreases the inflammatory reaction to the implant.

It is well known that the central nervous system (CNS) has a limited regenerative capacity and that many therapeutic molecules cannot cross the blood brain barrier (BBB). The use of biomaterials has emerged as an alternative to overcome these limitations. For many years, biomedical applications of chitosan have been studied due to its remarkable biological properties, biocompatibility, and high versatility. Moreover, the interest in this biomaterial for CNS biomedical implementation has increased because of its ability to cross the BBB, mucoadhesiveness, and hydrogel formation capacity. Several chitosan-based biomaterials have been applied with promising results as drug, cell and gene delivery vehicles. Moreover, their capacity to form porous scaffolds and to bear cells and biomolecules has offered a way to achieve neural regeneration. Therefore, this review aims to bring together recent works that highlight the potential of chitosan and its derivatives as adequate biomaterials for applications directed toward the CNS. First, an overview of chitosan and its derivatives is provided with an emphasis on the properties that favor different applications. Second, a compilation of works that employ chitosan-based biomaterials for drug delivery, gene therapy, tissue engineering, and regenerative medicine in the CNS is presented. Finally, the most interesting trends and future perspectives of chitosan and its derivatives applications in the CNS are shown.

Solid-state fermentation (SSF) has been largely employed during the last three decades to produce different biomolecules of industrial interest, particularly enzymes. Through the use of agroindustrial wastes as SSF substrates, an economic process of lipases production can be achieved. In this chapter we describe a comprehensive SSF method for producing an economical preparation of Rhizomucor miehei lipase, employing sugarcane bagasse and used vegetal oil as substrates. To demonstrate the usefulness of the lipase produced by this method, we utilized directly the dried fermented solid, as a heterogeneous biocatalyst for the ethanolysis of different fats and oils. Final ethyl ester conversions (90%, 24 h) were similar with those obtained using a commercial immobilized Rhizomucor miehei lipase at our best conditions. In this work we demonstrated that SSF is an easy and economical method for the production of lipases that can be used directly as heterogeneous biocatalysts for biodiesel production, employing low-cost feedstocks.

Solid-state fermentation (SSF) has been largely employed during the last three decades to produce different biomolecules of industrial interest, particularly enzymes. Through the use of agroindustrial wastes as SSF substrates, an economic process of lipases production can be achieved. In this chapter we describe a comprehensive SSF method for producing an economical preparation of Rhizomucor miehei lipase, employing sugarcane bagasse and used vegetal oil as substrates. To demonstrate the usefulness of the lipase produced by this method, we utilized directly the dried fermented solid, as a heterogeneous biocatalyst for the ethanolysis of different fats and oils. Final ethyl ester conversions (>90%, 24 h) were similar with those obtained using a commercial immobilized Rhizomucor miehei lipase at our best conditions. In this work we demonstrated that SSF is an easy and economical method for the production of lipases that can be used directly as heterogeneous biocatalysts for biodiesel production, employing low-cost feedstocks.