Juan Isaac Chávez Corona

The issue of stray cats and dogs is a global concern with considerable implications for animal welfare and public health. This review aims to provide an updated and comprehensive analysis of non-surgical contraceptive methods tested in studies controlled in vivo in feline and canine females. Immunocontraception via vaccination against gonadotropin-releasing hormone (GnRH), the luteinizing hormone receptor, zona pellucida proteins, and sperm, or use of viral-vectored delivery, is yet developing. Hormonal treatment (progestins, androgens, or GnRH) analogs act directly to block the reproductive axis. However, it produced essential side effects. Analogs of kisspeptin, non-steroid anti-inflammatory drugs such as firocoxib, and delivery of cytotoxins to the pituitary have shown non-conclusive results. Additional methods have also been tested, such as intraovarian injection of necrosing compounds or intravaginal and intrauterine devices. At present, neither of these methods offers permanent sterility that can replace surgical sterilization techniques. To our knowledge, none are currently authorized by the Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for contraceptive methods or sterilization of cats or dogs. Therefore, it is necessary to continue the development of a compound that warrants the sterility of cats and dogs.

El desarrollo de sistemas de liberación controlada basados en nanopartículas poliméricas constituye una estrategia clave para la administración de compuestos de interés farmacéutico, como la insulina. El quitosano, un polímero derivado de la quitina, por su biocompatibilidad y versatilidad, representa una plataforma prometedora; sin embargo, los métodos tradicionales de síntesis generan una alta dispersión en las propiedades fisicoquímicas, lo que limita su aplicación terapéutica. En este estudio se prepararon nanopartículas de quitosano de bajo peso molecular mediante modificaciones al método de gelación iónica, para el cual se utilizó como agente entrecruzante el tripolifosfato de sodio (TPP) y Eudragit ® L100-55 como recubrimiento entérico, con la finalidad de optimizar su desempeño y la entrega de insulina humana recombinante vía oral. Las nanopartículas presentaron un tamaño promedio de 299,86±21,33 nm, un índice de polidispersión (PDI) de 0,28 ± 0,05 y un potencial zeta de -24,93±1,10 mV, con morfología ovoide uniforme, confirmada por TEM. Se evidenció que el sistema tuvo una disminución importante en los niveles de glucosa sérica en un ensayo piloto in vivo en ratas Wistar.

El quitosano es un biopolímero versátil con aplicaciones en nanotecnología, de amplio interés en la síntesis de nanopartículas para administración de fármacos. Su grado de desacetilación (DD, por sus siglas en inglés) es un parámetro clave que influye en las propiedades de las nanopartículas tales como carga superficial, tamaño, y estabilidad coloidal. Sin embargo, su impacto en la funcionalidad de las nanopartículas aún requiere de un análisis detallado. El objetivo de este estudio fue explorar la relación entre el DD del quitosano y sus propiedades fisicoquímicas en la síntesis de nanopartículas, así como sus implicaciones en aplicaciones farmacéuticas. Para ello se realizó una revisión de la literatura en las bases de datos PubMed, Google Scholar y ScienceDirect, utilizando las palabras clave chitosan, deacetylation y nanoparticles, tanto en inglés como en español. Estas palabras clave se identificaron en los títulos y resúmenes de artículos de investigación. Se incluyeron estudios publicados entre el año 2000 y el 2025, abordando la síntesis, modificación o caracterización de nanopartículas de quitosano. Se excluyeron estudios sin reportar explícitamente el DD y su relación con propiedades funcionales o aplicaciones biomédicas, así como publicaciones duplicadas. Los resultados evidencian que un DD medio (70-85%) promueve una adecuada interacción con membranas celulares, común en aplicaciones farmacéuticas. Un DD bajo (< 70%) implica una menor interacción con membranas biológicas, por lo que tienen limitada utilidad en sistemas de liberación. Aunque un DD alto (86-95%) podría promover mayor adhesión a superficies celulares y mayor eficiencia de encapsulación, también pueden promover alta reactividad y posible citotoxicidad por su densidad de grupos amino libres. No obstante, un DD muy alto (> 95%) podría causar toxicidad, además de reducir la viscosidad, afectando la estabilidad de las formulaciones. Estos hallazgos subrayan la necesidad de ajustar el DD según la aplicación específica, optimizando la funcionalidad de las nanopartículas de quitosano. En conclusión, el control preciso del DD es esencial para maximizar el potencial del quitosano para la preparación de nanopartículas destinadas a la administración de fármacos. Además, futuros estudios deben enfocarse en la estandarización de métodos de producción de quitosano con grados de desacetilación específicos, y en su aplicación en nuevas terapias nanotecnológicas.

Delayed wound healing increases the wound’s vulnerability to possible infections, which may have lethal outcomes. The treatments available can be effective, but the urgency is not fully encompassed. The drug repositioning strategy proposes effective alternatives for enhancing medical therapies for chronic diseases. Likewise, applying wound dressings as biodegradable membranes is extremely attractive due to their ease of application, therapeutic effectiveness, and feasibility in industrial manufacturing. This article aims to demonstrate the pleiotropic effects during insulin repositioning in wound closure by employing a biopolymeric membrane-type formulation with insulin. We prepared biopolymeric membranes with sodium alginate cross-linked with calcium chloride, supported in a mixture of xanthan gum and guar gum, and plasticized with glycerol and sorbitol. Human insulin was combined with poloxamer 188 as a protein stabilizing agent. Our investigation encompassed physicochemical and mechanical characterization, antioxidant and biological activity through antibacterial tests, cell viability assessments, and scratch assays as an in vitro and in vivo wound model. We demonstrated that our biopolymeric insulin membranes exhibited adequate manipulation and suitable mechanical resistance, transparency, high swelling capability (1100%), and 30% antioxidant activity. Furthermore, they exhibited antibacterial activity (growth inhibition of S. aureus at 85% and P. aeruginosa at 75%, respectively), and insulin promoted wound closure in vitro with a 5.5-fold increase and 72% closure at 24 h. Also, insulin promoted in vivo wound closure with a 3.2-fold increase and 92% closure at 10 days compared with the groups without insulin, and this is the first report that demonstrates this therapeutic effect with two administrations of 0.7 IU. In conclusion, we developed a multifunctional insulin-loaded biopolymeric membrane in this study, with the main activity derived from insulin’s role in wound closure and antioxidant activity, augmented by the antimicrobial effect attributed to the polymer poloxamer 188. The synergistic combination of excipients enhances its usefulness and highlights our innovation as a promising material in wound healing materials.

Bisphenols such as bisphenol A (BPA), S (BPS), C (BPC), F (BPF), AF (BPAF), tetrabromobisphenol, nonylphenol, and octylphenol are plasticizers used worldwide to manufacture daily-use articles. Exposure to these compounds is related to many pathologies of public health importance, such as infertility. Using a protector compound against the reproductive toxicological effects of bisphenols is of scientific interest. Melatonin and vitamins have been tested, but the results are not conclusive. To this end, this systematic review and meta-analysis compared the response of reproductive variables to melatonin and vitamin administration as protectors against damage caused by bisphenols. We search for controlled studies of male rats exposed to bisphenols to induce alterations in reproduction, with at least one intervention group receiving melatonin or vitamins (B, C, or E). Also, molecular docking simulations were performed between the androgen (AR) and estrogen receptors (ER), melatonin, and vitamins. About 1234 records were initially found; finally, 13 studies were qualified for review and meta-analysis. Melatonin plus bisphenol improves sperm concentration and viability of sperm and increases testosterone serum levels compared with control groups; however, groups receiving vitamins plus bisphenols had lower sperm concentration, total testis weight, and testosterone serum levels than the control. In the docking analysis, vitamin E had the highest negative MolDock score, representing the best binding affinity with AR and ER, compared with other vitamins and melatonin in the docking. Our findings suggest that vitamins could act as an endocrine disruptor, and melatonin is most effective in protecting against the toxic effects of bisphenols.

This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5–6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.