Formulation and characterization of multifunctional polymer modified-iron oxide magnetic nanocarrier for doxorubicin delivery

Nanomedicines and cell-based therapies for embryonal tumors of the nervous system

Embryonal tumors of the nervous system are neoplasms predominantly affecting the pediatric population. Among the most common and aggressive ones are neuroblastoma (NB) and medulloblastoma (MB). NB is a sympathetic nervous system tumor, which is the most frequent extracranial solid pediatric cancer, usually detected in children under two. MB originates in the cerebellum and is one of the most lethal brain tumors in early childhood. Their tumorigenesis presents some similarities and both tumors often have treatment resistances and poor prognosis. High-risk (HR) patients require high dose chemotherapy cocktails associated with acute and long-term toxicities. Nanomedicine and cell therapy arise as potential solutions to improve the prognosis and quality of life of children suffering from these tumors. Indeed, nanomedicines have been demonstrated to efficiently reduce drug toxicity and improve drug efficacy. Moreover, these systems have been extensively studied in cancer research over the last few decades and an increasing number of anticancer nanocarriers for adult cancer treatment has reached the clinic. Among cell-based strategies, the clinically most advanced approach is chimeric-antigen receptor (CAR) T therapy for both pathologies, which is currently under investigation in phase I/II clinical trials. However, pediatric drug research is especially hampered due not only to ethical issues but also to the lack of efficient pre-clinical models and the inadequate design of clinical trials. This review provides an update on progress in the treatment of the main embryonal tumors of the nervous system using nanotechnology and cell-based therapies and discusses key issues behind the gap between preclinical studies and clinical trials in this specific area. Some directions to improve their translation into clinical practice and foster their development are also provided.

Biopolymer from Water Kefir as a Potential Clean-Label Ingredient for Health Applications: Evaluation of New Properties

The present work aimed to characterize the exopolysaccharide obtained from water kefir grains (EPSwk), a symbiotic association of probiotic microorganisms. New findings of the technological, mechanical, and biological properties of the sample were studied. The EPSwk polymer presented an Mw of 6.35 × 105 Da. The biopolymer also showed microcrystalline structure and characteristic thermal stability with maximum thermal degradation at 250 °C. The analysis of the monosaccharides of the EPSwk by gas chromatography demonstrated that the material is composed of glucose units (98 mol%). Additionally, EPSwk exhibited excellent emulsifying properties, film-forming ability, a low photodegradation rate (3.8%), and good mucoadhesive properties (adhesion Fmax of 1.065 N). EPSwk presented cytocompatibility and antibacterial activity against Escherichia coli and Staphylococcus aureus. The results of this study expand the potential application of the exopolysaccharide from water kefir as a potential clean-label raw material for pharmaceutical, biomedical, and cosmetic applications.

Gelatin-Graphene Oxide Nanocomposite Hydrogels for Kluyveromyces lactis Encapsulation: Potential Applications in Probiotics and Bioreactor Packings

Nutraceutical formulations based on probiotic microorganisms have gained significant attention over the past decade due to their beneficial properties on human health. Yeasts offer some advantages over other probiotic organisms, such as immunomodulatory properties, anticancer effects and effective suppression of pathogens. However, one of the main challenges for their oral administration is ensuring that cell viability remains high enough for a sustained therapeutic effect while avoiding possible substrate inhibition issues as they transit through the gastrointestinal (GI) tract. Here, we propose addressing these issues using a probiotic yeast encapsulation strategy, Kluyveromyces lactis, based on gelatin hydrogels doubly cross-linked with graphene oxide (GO) and glutaraldehyde to form highly resistant nanocomposite encapsulates. GO was selected here as a reinforcement agent due to its unique properties, including superior solubility and dispersibility in water and other solvents, high biocompatibility, antimicrobial activity, and response to electrical fields in its reduced form. Finally, GO has been reported to enhance the mechanical properties of several materials, including natural and synthetic polymers and ceramics. The synthesized GO-gelatin nanocomposite hydrogels were characterized in morphological, swelling, mechanical, thermal, and rheological properties and their ability to maintain probiotic cell viability. The obtained nanocomposites exhibited larger pore sizes for successful cell entrapment and proliferation, tunable degradation rates, pH-dependent swelling ratio, and higher mechanical stability and integrity in simulated GI media and during bioreactor operation. These results encourage us to consider the application of the obtained nanocomposites to not only formulate high-performance nutraceuticals but to extend it to tissue engineering, bioadhesives, smart coatings, controlled release systems, and bioproduction of highly added value metabolites.