This study aimed to validate an analytical method to determine DNA concentration using standard reference material (NIST SRM 2372) and Sprague Dawley rat and human DNA. Microvolumes were used to analyse DNA samples. Linearity showed correlation coefficients higher than R0.9950, and the precision value was 2 CV. Trueness based on bias and the percentage of recovery showed bias values lower than Z-test with a 95 confidence level and a recovery percentage within the range ( Rec=100±5), and the stability of the samples was 60days (24°C).

Composite Hydrogel of Poly(acrylamide) and Starch as Potential System for Controlled Release of Amoxicillin and Inhibition of Bacterial Growth: Novel composite hydrogels of poly(acrylamide) (PAAm) and starch, at different ratios, were studied as potential platforms for controlled release of amoxicillin. The composite hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and swelling kinetic measurements. The morphology analysis revealed the presence of starch granules well embedded within the PAAm network. The increase in starch content increased the rate of water uptake and the swelling degree at equilibrium. The amoxicillin release kinetics was sensitive to pH and temperature conditions. The in vitro bacterial growth inhibition of antibiotic-loaded hydrogels was tested though disc diffusion assays with Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and a carbapenemase producer Pseudomonas aeruginosa strain. The optimal release profile at physiological conditions and the powerful bacteria growth inhibition effects of amoxicillin-loaded hydrogels evidenced its potential for biomedical applications, particularly in oral administration and the local treatment of bacterial infections.

The development of thermosensitive bioadhesive hydrogels as multifunctional platforms for the controlled delivery of microbicides is a valuable contribution for the in situ treatment of vagina infections. In this work, novel semi-interpenetrating network (s-IPN) hydrogels were prepared by the entrapment of linear poly(methyl vinyl ether-alt-maleic anhydride) (PVME-MA) chains within crosslinked 3D structures of poly(N-isopropylacrylamide) (PNIPAAm). The multifunctional platforms were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermal techniques, rheological analysis, swelling kinetic measurements, and bioadhesion tests on porcine skin. The hydrogels exhibited an interconnected porous structure with defined boundaries. An elastic, solid-like behavior was predominant in all formulations. The swelling kinetics were strongly dependent on temperature (25 °C and 37 °C) and pH (7.4 and 4.5) conditions. The s-IPN with the highest content of PVME-MA displayed a significantly higher detachment force (0.413 ± 0.014 N) than the rest of the systems. The metronidazole loading in the s-IPN improved its bioadhesiveness. In vitro experiments showed a sustained release of the antibiotic molecules from the s-IPN up to 48 h (94%) in a medium simulating vaginal fluid, at 37 °C. The thermosensitive and bioadhesive PNIPAAm/PVME-MA systems showed a promising performance for the controlled release of metronidazole in the vaginal environment.

Recently, soluble forms of aluminum for human use or consumption have been determined to be potentially toxic due to their association with hepatic, neurological, hematological, neoplastic, and bone conditions. This study aims to assess the genotoxic effect of aluminum chloride on genomic instability associated with the onset of N-nitroso-N-methylurea (NMU)-induced breast cancer in Sprague Dawley rats. The dietary behavior of the rats was assessed, and the concentration of aluminum in the mammary glands was determined using atomic absorption spectroscopy. Genomic instability was determined in the histological sections of mammary glands stained with hematoxylin and eosin. Moreover, micronucleus in peripheral blood and comet assays were performed. The results of dietary behavior evaluation indicated no significant differences between the experimental treatments. However, aluminum concentration in breast tissues was high in the +2000Al/−NMU treatment. This experimental treatment caused moderate intraductal cell proliferation, lymph node hyperplasia, and serous gland adenoma. Furthermore, micronucleus and comet test results revealed that +2000Al/−NMU led to a genotoxic effect after a 10-day exposure and the damage was more evident after a 15-day exposure. Therefore, in conclusion, genomic instability is present and the experimental conditions assessed are not associated with breast cancer.

The production and loss of fine particles of activated carbon (AC) loaded with gold in the adsorption processes is a worldwide problem, mainly due to the behavior of increasing its adsorption capacity with respect to the decrease in particle size, which becomes relevant to determine the thermodynamic and kinetic activity of the gold adsorption and the economic impact of its loss, with the escape towards the later stages of the system of adsorption, desorption, and reactivation (ADR) plants of AC. Through the adsorption of gold in a synthetic medium with sodium cyanide concentration, using different particle sizes, AC weights, and adsorption times, data were generated for analysis by three different isotherm models, resulting in a better tendency for the Freundlich isotherm, from which thermodynamic parameters of ΔG equal to −2.022 kcal/mol, ΔH equal to −16.710 kcal/mol, and ΔS equal to −0.049 kcal/molK were obtained, which shows that it is a spontaneous, exothermic process with a lower degree of disorder. The kinetic analysis was performed with two different models, from which the pseudo-second-order model was used due to a better tendency and displayed a behavior that leaves open the interpretation of the increase in adsorption with respect to the decrease in the AC particle size but demonstrated the importance of recovering these particles in relation to their gold concentration and the economic impact from their poor recovery, which, for this case study, amounted to ~0.3 million dollars per year.