The development of new nanomaterials to promote wound healing is rising, because of their topical administration and easy functionalization with molecules that can improve and accelerate the process of healing. A nanocomposite of gold nanoparticles (AuNPs) functionalized with calreticulin was synthetized and evaluated. The ability of the nanocomposite to promote proliferation and migration was determined in vitro, and in vivo wound healing was evaluated using a mice model of diabetes established with streptozotocin (STZ). In vitro, the nanocomposite not affect the cell viability and the expression of proliferating cell nuclear antigen (PCNA). Moreover, the nanocomposite promotes the clonogenicity of keratinocytes, endothelial cells, and fibroblasts, and accelerates fibroblast migration. In vivo, mice treated with the nanocomposite presented significantly faster wound healing. The histological evaluation showed re-epithelization and the formation of granular tissue, as well as an increase of collagen deposition. Therefore, these results confirm the utility of AuNPs–calreticulin nanocomposites as potential treatment for wound healing of diabetic ulcers.

Biomaterials are often used in orthopedic surgery like cavity fillings. However, related complications often require long-term systemic antibiotics, device removal, and extended rehabilitation. Hydroxyapatite/silver (HA/Ag) composites have been proposed as implantation biomaterials owing to the osteogenic properties of hydroxyapatite and to the antimicrobial efficiency of silver. Nevertheless, higher silver concentrations induce cytotoxic effects. The aim of this study was to synthesize and characterize HA/Ag nanocomposites that will allow us to use lower concentrations of silver nanoparticles with better antimicrobial efficiency and anti-inflammatory properties. The characterization of HA/Ag was performed by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, and laser diffraction. Bioactivity was evaluated under a simulated body fluid. The viability of osteoblast like-cells (MG-63) was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) and the antimicrobial activity was evaluated by the standard McFarland method. The detection of nitric oxide was measured by a colorimetric assay and the inflammatory cytokines by flow cytometry. We obtained particulate composites of calcium phosphates identified as hydroxyapatite and silver nanoparticles. The bioactivity of the HA/Ag nanocomposites on SFB was confirmed by apatite formations. The viability of MG-63 cells was not affected. We also found antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans owing to the presence of silver nanoparticles at non-cytotoxic concentrations. HA/Ag reduced the release of nitric oxide and decreased the secretion of IL-1 and TNF-α in cells stimulated with Lipopolysaccharide (LPS). In conclusion, the inflammatory and antimicrobial capacity of the HA/Ag nanocomposites, as well as its bioactivity and low cytotoxicity make it a candidate as an implantation biomaterial for bone tissues engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

Aflatoxins can cause intoxication and poisoning in animals and humans. Among these molecules, aflatoxin B₁ (AFB₁) is the most dangerous because of its carcinogenic and mutagenic properties. To mitigate these effects, clay adsorbents are commonly included in the diet of animals to adsorb the carcinogens and prevent their absorption in the gastrointestinal tract. In this study, four clays, three smectites (C-1, C-2, and C-3), and one zeolite (C-4), were compared as adsorbents of AFB₁ and trace inorganic nutrients using an in vitro gastrointestinal model for poultry. Characterization of the clays using Fourier transform infrared spectroscopy revealed characteristic bands of smectites in C-1, C-2, and C-3 (stretching vibrations of Si-O, Al-O-Si, and Si-O-Si). The C-4 presented bands related to the bending vibration of structural units (Si-O-Si and Al-O-Si). X-ray diffraction analysis showed that C-1 is a montmorillonite, C-2 is a beidellite, C-3 is a beidellite-Ca-montmorillonite, and C-4 is a clinoptilolite. The elemental compositions of the clays showed alumina, silica, iron, calcium, and sodium contents. The cation exchange capacity was higher in C-3 clay (60.2 cmol(+)/kg) in contrast with the other clays. The AFB₁ adsorption of C-1 was the highest (99.5%; p ˂ 0.001), followed by C-2 (92.02%). However, all the clays also sequestered trace inorganic nutrients (Fe, Mn, Zn, and Se). Both smectites, montmorillonite and beidellite, were the most suitable for use as adsorbents of AFB₁.

As a class of secondary metabolites or toxins produced by fungi, aflatoxins can poison humans and animals; among them, aflatoxin B₁ (AFB₁) is the most dangerous one owing to its carcinogenic and mutagenic properties that increase risks for hepatocellular carcinoma in humans; hence, adsorbents such as smectites are commonly included in poultry feed to mitigate their effects. In this study, chitosan was crosslinked with sodium dodecyl sulfate (SDS) to form an insoluble polymer complex that is stable at the relevant physiological pH levels. The characterization via Fourier transforms infrared spectroscopy revealed the interaction between the sulfate groups of the SDS and the amine group of chitosan (1,016 and 819 cm⁻¹); this result was further confirmed by the X-ray diffraction patterns with a change in the crystalline structure of the chitosan-insoluble complex (2θ = 4.76°, 7°, and 22°). The morphology of the chitosan-insoluble complex obtained using a field emission scanning electron microscope (FE-SEM) revealed that particles were slightly porous. After characterization, the performance of the chemically modified polymer complex was evaluated as an adsorbent for AFB₁ and compared with those of the unmodified chitosan, soluble chitosan complex, and commercial montmorillonite clay binder. In addition, the polymer complex was investigated as an adsorbent in an in vitro model for the poultry gastrointestinal system. Sequestration of AFB₁ by a chemically modified polymer complex was 93.4%, equivalent to that of commercial montmorillonite clay (99.5%). However, these treatments also sequestered microminerals, particularly selenium and iron. This pH-stable, high-capacity adsorbent could be used in poultry feed to reduce the uptake of AFB₁.

This study evaluated the effects of liquid oregano oil, chitosan nanoparticles with encapsulated liquid oregano oil, and a negative control of empty chitosan nanoparticles on in vitro ruminal fermentation. Three Boer goats were used as ruminal fluid donors, fed with a formulated ration for 21 d for inoculum adaptation. Treatments tested on in vitro assays were diet without oregano oil or nanoparticles (CON); diet with 100 ppm of oregano oil in nanoparticles (100N); diet with 300 ppm of liquid oregano oil (300L); diet with 300 ppm of oregano oil in nanoparticles (300N); and diet with 300 ppm of empty nanoparticles (300CHN). The variables studied were in vitro dry matter digestibility (ivDMD), in vitro neutral detergent fiber digestibility (ivNDFD_om), total gas production (TGP), ammonia nitrogen concentration (NH₃), and pH. The experimental design was a randomized complete block design. Linear and quadratic regressions were used to identify dependence and inflection points. The ivDMD increased at 12, 36, and 48 h, with 300N and with 300L exhibiting increased ivNDFD_om at 36 h. Ruminal pH was highest (p < 0.05) with 300CHN at 36 h. For first-order regression analysis of TGP, coefficients (β) were highest (p < 0.05) for 300N. In conclusion, 300N increased ruminal fermentation in vitro, as reflected by increases in ivDMD, ivNDFD_om, and TGP.

Dialyzable leukocyte extracts are clinically used under different commercial names (IMMUNEPOTENT CRP^®, IMMODIN^®, Transferon^®) to modulate the immune response altered by pathological conditions such as cancer, inflammation, and viral infections. The purpose of this study is to improve the production process of bovine dialyzable leukocyte extract without decreasing its biological activities (antioxidant, anti-inflammatory, and antitumoral). Our product modification consists of adding a dry heating step in the production process. In this study, we evaluated and compared the chemical composition (bromatological analysis), physical structure (infrared spectroscopy, X-ray diffraction, SEM, and zeta potential) and biological function of the dialyzable leukocyte extracts obtained from fresh and dry bovine spleens. Our results showed that the use of a drying step in the production process of the bovine dialyzable leukocyte extract (bDLE) did not affect its antioxidant and anti-inflammatory effects and it improved its antitumor properties. We suggest that this process modification could be applied to other biological products, such as dialyzable leukocyte extracts derived from other sources, in order to improve its functionality and formulation.