Alva Rocío Castillo-González

Red blood cells represent a widely used cellular model in cytotoxicity studies, particularly in hemocompatibility assessments. As enucleated cells, which are abundant and easily accessible in both humans and animals, red blood cells allow for rapid, reproducible, and low-cost evaluation of the toxicity of bioactive compounds, whether natural, synthetic, or nanoparticulate. From a functional perspective, the red blood cell membrane is highly sensitive to physical and chemical environmental changes (osmolarity, temperature, pH, and the presence of oxidizing agents). This sensitivity makes red blood cells an effective biosensor for detecting membrane damage, hemolysis, oxidative stress, methemoglobin formation, and aggregation processes. Therefore, in vitro tests using red blood cells allow for the preliminary evaluation in preclinical development, particularly for the early screening of cytotoxicity, membrane-disruptive effects, and hemocompatibility of small molecules, nanomaterials, and blood-contacting biomaterials. These techniques include hemocompatibility tests, evaluation of oxidative and osmotic damage, and evaluation of erythrocyte aggregation and function. However, the use of red blood cells as a cytotoxicity model also has significant limitations. As anucleate cells, erythrocytes lack organelles such as nuclei, mitochondria, or lysosomes, which prevents the evaluation of their effects on key intracellular processes such as protein synthesis, cell signaling, apoptosis, or endoplasmic reticulum stress. This lack of cellular complexity limits their usefulness as a sole model in studies of systemic toxicity or tissue-specific cytotoxicity. These tools offer an effective preliminary approach to anticipating risks in biomedical and pharmacological research.

The development of functional biomaterials based on natural polymers has gained increasing relevance due to the growing demand for sustainable and bioactive alternatives for biomedical and technological applications. In this study, chitosan was obtained from shrimp exoskeletons and used to formulate active films enriched with Mexican propolis, aiming to evaluate the influence of the extract on the physicochemical and functional properties of the resulting biomaterial. Propolis was incorporated into the chitosan film-forming solution at a final concentration of 1.0% (v/v). The propolis employed met the requirements of the Mexican Official Standard NOM-003-SAG/GAN-2017 regarding flavonoid content, total phenolic compounds, and antimicrobial activity; additionally, it was evaluated through antioxidant activity, hemolysis, and acute toxicity (LD₅₀) assays to provide a broader biological and safety assessment. The extracted chitosan exhibited a degree of deacetylation of 74% and characteristic FTIR spectral features comparable to those of commercial chitosan, confirming the quality of the obtained polymer. Chitosan–propolis films exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans, whereas pure chitosan films showed no inhibitory effect. Thermal analyses (TGA/DSC) revealed a slight reduction in thermal stability due to the incorporation of thermolabile polyphenolic compounds, along with increased thermal complexity of the system. SEM observations demonstrated reduced microbial adhesion and marked morphological damage in microorganisms exposed to the functionalized films. Overall, the incorporation of Mexican propolis enabled the development of a hybrid biomaterial with enhanced antimicrobial performance and potential application in wound dressings and bioactive coatings.

Microalgae are increasingly recognized as valuable dietary supplements due to their rich nutritional composition and the presence of bioactive metabolites with antioxidant, antitumor, and metabolism-modulating activities. This study evaluated the nutraceutical potential of a methanolic extract of Scenedesmus sp. using an integrated in vitro, in vivo, and metabolomic approach. The extract exhibited selective cytotoxicity against L5178Y-R murine lymphoma cells while showing low toxicity toward human peripheral blood mononuclear cells, indicating a favorable safety and selectivity profile. Additionally, it demonstrated moderate antioxidant activity, a significant antihemolytic effect, and no hemolytic activity even at high concentrations, supporting its hematological safety. In vivo assays showed that oral administration of doses up to 1000 mg/kg was well tolerated, with no adverse effects on body weight or hepatic biochemical markers. Treated animals displayed improved systemic antioxidant responses and enhanced glucose tolerance. Metabolomic analysis revealed a profile enriched in essential amino acids, osmolytes, organic acids, and bioactive metabolites such as β-hydroxybutyrate and betaine, compounds associated with metabolic regulation, redox balance, and epigenetic modulation. Overall, these findings highlight Scenedesmus sp. as a promising nutraceutical source with potential application as a complementary strategy for cancer prevention or treatment.

Background: Developing reliable and cost-effective decellularization methods is critical for advancing tissue engineering and regenerative medicine, particularly in regions with limited access to specialized perfusion systems. Methods: This study standardized a gravity-assisted perfusion protocol for rat liver decellularization, designed to operate without pumps or pressurized equipment. Adult Wistar rat livers were processed through a gravity-driven vascular flushing method and compared with a conventional immersion-based protocol. The resulting scaffolds were evaluated by macroscopic inspection, histological staining (Masson’s trichrome), and residual DNA quantification. Results: The gravity-assisted perfusion method achieved more efficient cellular removal and superior preservation of extracellular matrix (ECM) integrity compared with immersion. Residual DNA levels were 3.7 ng/mg in perfused samples, 209.47 ng/mg in immersed samples, and 331.97 ng/mg in controls, confirming a statistically significant reduction (p < 0.05). Only the perfused group met the accepted threshold for effective decellularization (<50 ng/mg dry tissue). Histological analysis corroborated these findings, showing the absence of nuclei and the preservation of collagen architecture characteristic of a structurally intact ECM. Conclusions: This low-cost, reproducible, and technically simple system enables the generation of high-quality acellular hepatic scaffolds without mechanical pumps. Its accessibility and scalability make it suitable for laboratories with limited infrastructure and educational settings. Moreover, this gravity-assisted approach provides a foundation for future recellularization and preclinical studies aimed at developing bioengineered liver constructs for regenerative and transplant applications.

Wound healing is a complex process, and propolis, a natural resin with antimicrobial, anti-inflammatory, and antioxidant properties, emerges as a promising candidate for its treatment. This systematic review analyzed 26 studies on propolis-functionalized biomaterials. Great diversity was observed in materials and incorporation techniques, including direct blending, surface coating, and nanoencapsulation. Mostly based on polysaccharides like chitosan, pectin, and bacterial cellulose, these formulations showed biocompatibility, biodegradability, and promoted inflammation reduction and tissue repair. In vitro assays confirmed high biocompatibility (>80% cell viability) and antimicrobial activity, while in vivo studies validated regenerative benefits. Despite their potential, marked heterogeneity in propolis composition (intrinsically variable due to its botanical and geographical origin, and processing methods), coupled with diverse concentrations used and the lack of standardization in assessment methods and results reporting, significantly limits cross-study comparability and reproducibility. Overcoming these challenges requires promoting greater standardization in extraction, characterization, and evaluation protocols, including chemical fingerprinting and more detailed and consistent reporting of findings. Despite these limitations, propolis–polysaccharide systems hold strong clinical potential, with further standardization and well-designed preclinical studies being essential for their effective translation, especially in chronic wound management.

Nosocomial infections caused by Candida albicans pose serious challenges to healthcare systems due to their persistence on medical surfaces and resistance to conventional disinfectants. This study evaluates antifungal properties of SnO₂ doped with silver and cuprite nanoparticles and WO₃ thin films, as well as cobalt (CoFe₂O₄) and cobalt–nickel (Co_0.5Ni₀.₅Fe₂O₄) ferrite nanoparticles, activated by ultraviolet C (UVC) radiation, direct electric current (up to 100 V), and magnetic fields. SnO₂ films were synthesized by Spray Pyrolysis and WO₃ by Sputtering deposition, Ferrites nanoparticles by sol–gel, while metallic nanoparticles were synthetized via chemical reduction. Characterization consisted mainly of SEM, TEM, and XRD, and their antimicrobial activity was tested against C. albicans. WO₃ films achieved 86.2% fungal inhibition after 5 min of UVC exposure. SnO₂ films doped with nanoparticles reached 100% inhibition when combined with UVC and 100 V. Ferrite nanoparticles alone showed moderate activity (21.9%–40.4%) but exhibited strong surface adhesion to fungal cells, indicating potential for magnetically guided antifungal therapies. These results demonstrate the feasibility of using multifunctional nanomaterials for rapid, non-chemical disinfection. The materials are low-cost, scalable, and adaptable to hospital settings, making them promising candidates for reducing healthcare-associated fungal infections through advanced surface sterilization technologies.

Postsurgical infections are an important cause of implant failure, and biomaterials such as Chitosan can be used as an antimicrobial coating to address this important problem. Characterization of silver distribution was performed by several methods, including Electron scanning microscopy (SEM), Inductively coupled plasma (ICP), and Infrared spectrometry (IR). Antimicrobial activity was tested against Candida albicans ATCC 10231, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa BAA-1744 ATCC 109246. The inhibition assays showed that Chitosan films inhibited 68% of C. albicans growth and 23.5% of E. coli growth; the rest of the microorganisms did not have any statistically relevant inhibition. E. coli, P. aeruginosa, and C. albicans were completely inhibited in films with 0.25 mg/mL of AgNO₃ and inhibited 82.5% of S. aureus. The mechanism of integration and release of silver in the films was analyzed by the Density Functional Theory (DFT), considering this analysis of geometry optimization as well as infrared spectroscopy. DFT analysis showed that AgNO₃ is not trapped by covalence in chitosan, being a more stable system when it is closer to an OH group. Chitosan films functionalized with antimicrobial compounds are a promising antimicrobial coating for use in biomaterials to prevent postsurgical complications.

A functional food as a matrix based on a blend of carbohydrate polymers (25% maltodextrin and 75% inulin) with quercetin and Bacillus claussi to supply antioxidant and probiotic properties was prepared by spray drying. The powders were characterized physiochemically, including by moisture adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), and modulated differential scanning calorimetry (MDSC). The type III adsorption isotherm developed at 35 °C presented a monolayer content of 2.79 g of water for every 100 g of dry sample. The microstructure determined by XRD presented three regions identified as amorphous, semicrystalline, and crystalline-rubbery states. SEM micrographs showed variations in the morphology according to the microstructural regions as (i) spherical particles with smooth surfaces, (ii) a mixture of spherical particles and irregular particles with heterogeneous surfaces, and (iii) agglomerated irregular-shape particles. The blend’s functional performance demonstrated antioxidant activities of approximately 50% of DPPH scavenging capacity and viability values of 6.5 Log10 CFU/g. These results demonstrated that the blend displayed functional food behavior over the complete interval of water activities. The equilibrium state diagram was significant for identifying the storage conditions that promote the preservation of functional food properties and those where the collapse of the microstructure occurs.