Search Results (6)

Background: Aneurysmal subarachnoid hemorrhage (aSAH) induces complex systemic inflammatory and metabolic responses that may influence clinical outcome. DSC provides an integrative biophysical readout of proteome-level thermodynamic behavior rather than protein-specific identification or quantification; however, its applicability in neurocritical conditions remains largely unexplored. This pilot study aimed to explore whether serum DSC profiles show preliminary associations with clinical severity and neurological outcomes after aSAH. Methods: Serum samples collected on day 1 after aSAH were analyzed by DSC and compared with healthy control samples. A small patient cohort was stratified according to clinical severity and neurological outcome. Thermograms were evaluated based on melting temperatures (Tm), calorimetric enthalpy (ΔHcal), heat capacity changes (ΔCp), and the relative contributions of major serum protein components. Results: Healthy controls exhibited characteristic DSC profiles dominated by a cooperative albumin transition at approximately 65–66 °C. In this limited cohort, patients with severe clinical conditions and unfavorable outcomes displayed marked thermogram reorganization, including increased albumin Tm, reduced unfolding cooperativity, decreased ΔCp, and enhanced high-temperature immunoglobulin-related contributions. Patients with mild condition and favorable outcome showed profiles more similar to those of the controls. Notably, patients with severe conditions but favorable outcomes demonstrated heterogeneous albumin-related thermal domains, which may reflect individual-level variability and suggesting dynamic proteomic heterogeneity at the early post-ictus phase. Given the small group sizes, these patterns should be interpreted as exploratory and hypothesis-generating. Conclusions: This pilot exploratory study suggests that serum DSC may capture preliminary thermoanalytical patterns associated with clinical outcomes after aSAH. While the findings indicate the potential of DSC as a systems-level tool in neurocritical care, larger, well-powered studies are required to validate these observations and assess their robustness and generalizability. Full article

Background/Objectives: We report the development of a novel intraocular sustained-release implantable pharmaceutical formulation, designed to be placed in the anterior chamber of the eye after cataract surgery. The device is intended to reduce postoperative inflammation, and to prevent opportunistic bacterial infections that may lead to endophthalmitis. Methods: The implants were produced via hot-melt extrusion, using a twin-screw extruder to process a homogeneous mixture of polylactide-co-glycolic acid, moxifloxacin hydrochloride (MOX HCl) and dexamethasone (DEX). Quality control tests included drug content determination, release rate profile evaluation, and several instrumental characterization techniques (scanning electron microscopy (SEM), confocal Raman microscopy, differential scanning calorimetry, and X-ray diffraction). Long-term and accelerated stability tests were also performed, following ICH guidelines. Sterilization was achieved by exposing samples to gamma radiation. In vivo exploratory studies were carried out in healthy rabbits to evaluate the safety and overall performance of the implantable formulation. Results: In terms of quality control, drug content was found to be homogeneously distributed throughout the implants, and it also met the label claim. In vitro release rate was constant for MOX HCl, but non-linear for DEX, increasing over time. In vivo preliminary tests showed that the inserts completely biodegraded within approximately 20 days. No clinical signs of anterior segment toxic syndrome or statistically significant intraocular pressure differences were found between treatment and control groups. Conclusions: The implants developed in this study can act as sustained-release depots for the delivery of both DEX and MOX HCl, and are biocompatible with ocular structures. Full article

Vitamins are widely found in nature, for example, in plants and fruits. Ascorbic acid and nicotinamide are examples of these compounds that have potent antioxidant properties, besides stimulating collagen production and depigmenting properties that protect the skin from premature aging. To overcome the skin barrier and reduce the instability of antioxidant compounds, alternative systems have been developed to facilitate the delivery of antioxidants, making them efficiently available to the tissue for an extended time without causing damage or toxicity. The objective of this study was to obtain chitosan biodegradable microparticles containing ascorbic acid and nicotinamide for topical delivery. The microparticles were obtained by spray drying and characterized chemically by means of scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and differential exploratory calorimetry. The drugs were successfully encapsulated and the microparticles showed positive zeta potential. In vitro release assays showed a sustained release profile. The evaluation of ex vivo skin permeation and retention demonstrated low permeation and adequate retention of the compounds in the epidermis/dermis, suggesting the efficient delivery from the obtained microparticles. Antibacterial assays have shown that microparticles can inhibit the growth of microorganisms in a time- and dose-dependent manner, corroborating their use in cosmetic products for application on the skin. Full article

This work aimed to produce collagens and hydrolysates with antimicrobial and antioxidant activity from sheep slaughter by-products. The by-products (sheep and lamb) were treated and extracted. The collagens were hydrolyzed with the enzyme Alcalase^®. The spectra of collagens and hydrolysates were similar (amide bands I, II, III, A, B). The bands presented by the collagens (α₁, α₂, β) were characteristic of type I collagen. The hydrolysates showed molecular weight peptides equal to/lower than 15 kDa. Collagens had a denaturation temperature of 39.32 (lamb) and 36.38 °C (sheep), whereas the hydrolysates did not undergo thermal transition. Hydrolysates showed lower values of antioxidant activity (AA) than the collagens. The collagens from lamb and from sheep displayed an AA of 13.4% (concentration of 0.0002%) and 13.1% (concentration of 0.0005%), respectively. At the concentration of 0.0020%, the lamb hydrolysates displayed an AA of 10.2%, whereas the sheep hydrolysates had an AA of only 1.98%. Collagen also showed higher antimicrobial activity compared to hydrolysates, requiring a lower concentration to inhibit the microorganisms tested. Sheep slaughter by-products proved to be a viable source for obtaining protein hydrolysates and collagens with antimicrobial and antioxidant activity, which can be applied in the development of nutraceuticals beneficial to human health. Full article

Soft matter that undergoes programmed macroscopic responses to molecular analytes has potential utility in a range of health and safety-related contexts. In this study, we report the design of a nematic liquid crystal (LC) composition that forms through dimerization of carboxylic acids and responds to the presence of vapors of organoamines by undergoing a visually distinct phase transition to an isotropic phase. Specifically, we screened mixtures of two carboxylic acids, 4-butylbenzoic acid and trans-4-pentylcyclohexanecarboxylic acid, and found select compositions that exhibited a nematic phase from 30.6 to 111.7 °C during heating and 110.6 to 3.1 °C during cooling. The metastable nematic phase formed at ambient temperatures was found to be long-lived (>5 days), thus enabling the use of the LC as a chemoresponsive optical material. By comparing experimental infrared (IR) spectra of the LC phase with vibrational frequencies calculated using density functional theory (DFT), we show that it is possible to distinguish between the presence of monomers, homodimers and heterodimers in the mixture, leading us to conclude that a one-to-one heterodimer is the dominant species within this LC composition. Further support for this conclusion is obtained by using differential scanning calorimetry. Exposure of the LC to 12 ppm triethylamine (TEA) triggers a phase transition to an isotropic phase, which we show by IR spectroscopy to be driven by an acid-base reaction, leading to the formation of ammonium carboxylate salts. We characterized the dynamics of the phase transition and found that it proceeds via a characteristic spatiotemporal pathway involving the nucleation, growth, and coalescence of isotropic domains, thus amplifying the atomic-scale acid-base reaction into an information-rich optical output. In contrast to TEA, we determined via both experiment and computation that neither hydrogen bonding donor or acceptor molecules, such as water, dimethyl methylphosphonate, ethylene oxide or formaldehyde, disrupt the heterodimers formed in the LC, hinting that the phase transition (including spatial-temporal characteristics of the pathway) induced in this class of hydrogen bonded LC may offer the basis of a facile and chemically selective way of reporting the presence of volatile amines. This proposal is supported by exploratory experiments in which we show that it is possible to trigger a phase transition in the LC by exposure to volatile amines emitted from rotting fish. Overall, these results provide new principles for the design of chemoresponsive soft matter based on hydrogen bonded LCs that may find use as the basis of low-cost visual indicators of chemical environments. Full article

Downstream waste from industry and other industrial processes could increase concentration of heavy metals in water. These pollutants are commonly removed by adsorption because it is an effective and economical method. Previously, we reported adsorption capacity of a chitosan/polyurethane/titanium dioxide (TiO₂) composite for three ions in a dynamic wastewater system. There, increasing the chitosan concentration in composite increased the cation removal as well; however, for ratios higher than 50% of chitosan/TiO₂, the manufacturing cost increased significantly. In this work, we address the manufacturing cost problem by proposing a new formulation of the composite. Our hypothesis is that inulin could replace chitosan in the composite formulation, either wholly or in part. In this exploratory research, three blends were prepared with a polyurethane matrix using inulin or/and chitosan. Adsorption was evaluated using a colorimetric method and the Langmuir and Freundlich models. Fourier-transform infrared spectroscopy (FTIR) spectra, scanning electron microscopy (SEM) micrographs, differential scanning calorimetry and thermogravimetric analysis curves were obtained to characterize blends. Results indicate that blends are suitable for toxic materials removal (specifically lead II, Pb²⁺). Material characterization indicates that polysaccharides were distributed in polyurethane’s external part, thus improving adsorption. Thermal degradation of materials was found above 200 °C. Comparing the blends data, inulin could replace chitosan in part and thereby improve the cost efficiency and scalability of the production process of the polyurethane based-adsorbent. Further research with different inulin/chitosan ratios in the adsorbent and experiments with a dynamic system are justified. Full article