Evaluation of the Antibacterial, Anti-Cervical Cancer Capacity, and Biocompatibility of Different Graphene Oxides

Cancer stands as one of the deadliest diseases in human history, marked by an inferior prognosis. While traditional therapeutic methods like surgery, chemotherapy, and radiation have demonstrated success in inhibiting tumor cell growth, their side effects often limit overall benefits and patient acceptance. In this regard, three different graphene oxides (GO) with variations in their degrees of oxidation were studied chemically and tissue-wise. The accuracy of the synthesis of the different GO was verified by robust techniques using X-ray photoelectron spectroscopy (XPS), as well as conventional techniques such as infrared spectroscopy (FTIR), RAMAN spectroscopy, and X-ray diffraction (XRD). The presence of oxygenated groups was of great importance. It affected the physicochemical properties of each of the different graphene oxides demonstrated in the presence of new vibrational modes related to the formation of new bonds promoted by the graphitization of the materials. The toxicity analysis in the Hep-2 cell line of graphene oxide formulations at 250 µg/mL on the viability and proliferation of these tumor cells showed low activity. GO formulations did not show high antibacterial activity against Staphylococcus aureus and Escherichia coli strains. However, the different graphene oxides showed biocompatibility in the subdermal implantation model for 30, 60, and 90 days in the biomodels. This allowed healing by restoring hair and tissue architecture without triggering an aggressive immune response.

Chitosan-Polyvinyl Alcohol Nanocomposites for Regenerative Therapy

Tissue accidents provide numerous pathways for pathogens to invade and flourish, causing additional harm to the host tissue while impeding its natural healing and regeneration. Essential oils (EOs) exhibit rapid and effective antimicrobial properties without promoting bacterial resistance. Clove oils (CEO) demonstrate robust antimicrobial activity against different pathogens. Chitosan (CS) is a natural, partially deacetylated polyamine widely recognized for its vast antimicrobial capacity. In this study, we present the synthesis of four membrane formulations utilizing CS, polyvinyl alcohol (PVA), and glycerol (Gly) incorporated with CEO and nanobioglass (n-BGs) for applications in subdermal tissue regeneration. Our analysis of the membranes' thermal stability and chemical composition provided strong evidence for successfully blending polymers with the entrapment of the essential oil. The incorporation of the CEO in the composite was evidenced by the increase in the intensity of the band of C-O-C in the FTIR; furthermore, the increase in diffraction peaks, as well as the broadening, provide evidence that the introduction of CEO perturbed the crystal structure. The morphological examination conducted using scanning electron microscopy (SEM) revealed that the incorporation of CEO resulted in smooth surfaces, in contrast to the porous morphologies observed with the n-BGs. A histological examination of the implanted membranes demonstrated their biocompatibility and biodegradability, particularly after a 60-day implantation period. The degradation process of more extensive membranes involved connective tissue composed of type III collagen fibers, blood vessels, and inflammatory cells, which supported the reabsorption of the composite membranes, evidencing the material's biocompatibility.

Synthesis, Characterization, and Optimization Studies of Polycaprolactone/Polylactic Acid/Titanium Dioxide Nanoparticle/Orange Essential Oil Membranes for Biomedical Applications

The development of scaffolds for cell regeneration has increased because they must have adequate biocompatibility and mechanical properties to be applied in tissue engineering. In this sense, incorporating nanofillers or essential oils has allowed new architectures to promote cell proliferation and regeneration of new tissue. With this goal, we prepared four membranes based on polylactic acid (PLA), polycaprolactone (PCL), titanium dioxide nanoparticles (TiO₂-NPs), and orange essential oil (OEO) by the drop-casting method. The preparation of TiO₂-NPs followed the sol-gel process with spherical morphology and an average size of 13.39 nm ± 2.28 nm. The results show how the TiO₂-NP properties predominate over the crystallization processes, reflected in the decreasing crystallinity percentage from 5.2% to 0.6% in the membranes. On the other hand, when OEO and TiO₂-NPs are introduced into a membrane, they act synergistically due to the inclusion of highly conjugated thermostable molecules and the thermal properties of TiO₂-NPs. Finally, incorporating OEO and TiO₂-NPs promotes tissue regeneration due to the decrease in inflammatory infiltrate and the appearance of connective tissue. These results demonstrate the great potential for biomedical applications of the membranes prepared.

Insulin modifies the proliferation and function of chicken testis cells

We investigated whether insulin plays a role in the proliferation and androgen production of chick testis cells. Testes from 18-d-old chick embryos or newly hatched chickens were dissociated and precultured in the presence of fetal bovine serum (FBS) for 24 h. After this period, testis cells from 18-d-old chick embryos were cultured in serum-free medium for 1 h with 0, 10, 50, or 100 microg/mL of insulin and were then exposed to human chorionic gonadotropin (hCG) for 3 h. In addition, some cells were incubated for 18 h with only insulin or insulin plus hCG. Androgens were measured by radioimmunoassay in the spent media. To study the influence of insulin on testis cell proliferation, cells were exposed to insulin for 18 h. A pulse of 3H-thymidine was added thereafter. We found that 18-d-old embryonic testis cells responded to hCG, increasing androgen production. Incubation with insulin for 1 h did not affect basal androgen production but modified the subsequent response to hCG. The addition of insulin plus hCG for 18 h resulted in important downregulation of the hCG effect. In addition, insulin significantly increased the proliferation of embryonic testis cells. The cells from testes of newly hatched chickens were precultured as described for embryonic cells and then exposed to insulin for 1 h in a serum-free medium. This treatment significantly increased the basal androgen production. Insulin also significantly enhanced the response to hCG of the testis cells from newly hatched chickens. These results strongly suggest that insulin has a role in the activity and in the proliferation of cultured testis cells throughout the perinatal period.

[Expression of oncogenes (c-myc-neu) and prolactin receptor (PRLr) in tissues of women with endometriosis]

Endometriosis is a disease of unknown ethology; there are several theories that are unproven. It is known that women with such disease present with infertility, and that recurrence is very high, and apparently not depending of estrogenic stimulus. This phenomenon has been contributed to other growth factors and some oncogens. There are few studies about oncogens or other hormonal receptors; so, this study tries to evaluate them in eutopic tissue and in ectopic one of women with previous diagnosis of endometriosis. Our results show that myc as PRLr are expressed differently in the different tissues; and neu is expressed in the same way in both tissues. So, it was concluded that the cells of the endometriosis focus, have a differential status relating to expression of some of their genes, which target on their development and maintenance in a hormonal environment which differs from the uterine cavity.

The effects of fetal serum and gonadotropins on testosterone production by cultured chick testicular cells

This report describes the influences of fetal serum and gonadotropins on the development and function of chick testicular cells in a culture system that allows long term control of culture conditions. Testis of new born male chicks were dissociated and cultured in different conditions and the production of testosterone measured by RIA. 1. To investigate the effect of serum the cells were wither cultured in a defined medium composed by Dulbecco's modified medium (DMM) plus 0.1% albumin or media containing DMM plus 10% fetal bovine serum (FBS). The presence of serum increased protein content of the cultures, but no differences were found in basal testosterone production. When hCG (2IU/ml) was added to both culture media, the increment in testosterone production hence produced, was greater when cells were cultured in defined medium. 2. Cells were precultured for 24 hr in either defined serum media with or without hCG. The media were then replaced with DMM plus BSA and 1-methyl 3-isobutyl xanthine (IBMX) in the presence or absence of hCG and cells further incubated for 2 hr. Addition of hCG increased testosterone production by cells cultured in defined medium and enhanced its subsequent response to hCG stimulation. Cells cultured in serum medium maintained their ability to respond to hCG, but the addition of this hormone to the medium, abolished the response to further hCG-stimulation. 3. hCG caused a dose-related increased in testosterone production by cells cultured in defined and serum containing media, but concentrations of hCG above 2 IU/ml depressed testosterone production in the latter group.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms of hormonal and antihormonal action of contraceptive progestins at the molecular level

19-Nor synthetic progestins undergo extensive metabolism at the target cells. The resulting metabolic conversion products interact with putative steroid receptors within the cells, and through those interactions, they may exert either agonistic, synergistic and antagonistic hormonal effects. Studies conducted in our laboratories have disclosed that norethisterone (NET) and D-(1) norgestrel (LNG), two widely used contraceptive progestins, are biotransformed to several A-ring reduced (dihydro and tetrahydro) derivatives. The resulting metabolites 5 alpha-dihydro NET (5 alpha-NET) and 5 alpha-dihydro LNG bind with relative high affinity to the progesterone and androgen receptors. To gain insight into the underlying molecular events mediating the mode of action of NET and its neutral metabolites, we have examined the expression of their biological effects at target organs by using the rabbit uteroglobin gene model and the beta-glucuronidase activity of the mouse kidney. The results of a series of experiments seem to indicate that the enzyme-mediated formation of the 5 alpha (trans A/B ring junction) NET derivative results in a significant diminution of its progestational and androgenic potencies. Furthermore, 5 alpha-NET acquire a potent anti-progestational/contragestational effect as assessed in the female rabbit. These results demonstrated that 5 alpha-reduction of 19-nor progestins exerts a paradoxical effect, at least in terms of their hormone-like effects. The overall data are in line with the concept that metabolism of synthetic progestins at hormone-sensitive organs modulates their mechanisms of action.