Search Results (29)

This paper proposes an innovative contact sponge–fluorescent tracer technique for the rapid, non-destructive detection of 1–100 μm microcracks in cementitious materials. The technique combines a porous sponge carrier with a moisture-sensitive fluorescent tracer: after the sponge adsorbs the aqueous dye solution, capillary action drives fluorescent molecules into microcracks upon contact with the wall, ensuring stable luminescence during a 30-day continuous observation period. This technique was applied to cement paste specimens with three different water-to-cement ratios, dried at 105 °C for varying durations to induce drying–shrinkage microcracks. Results demonstrate that the technique clearly characterizes microcrack networks with high resolution and excellent stability. Under the same drying duration, the average microcrack width decreases with an increasing water-to-cement ratio, while the total crack length and fractal dimension increase. Regression analysis reveals that the average crack width is the primary factor controlling capillary water absorption. This method enables the early detection of microcracks in critical infrastructure such as tunnels and bridges, facilitating timely maintenance and reducing deterioration risk. Full article

Cleaning historical silk textiles is a particularly sensitive operation that requires precise control to prevent mechanical or chemical damage. In this study, we investigate using flexible PVA–borax-based gels to remove soot from silk, i.e., polyvinyl alcohol–borax (PVA-B) gels and polyvinyl alcohol–borax–agarose double network gels (PVA-B/AG DN) loaded with different cleaning agents—namely, 30% ethanol and 1% Ecosurf EH-6—in addition to plain gels loaded with water. These gel formulations were tested on simplified model systems (SMS) and were applied using two methods: placing and tamping. The cleaning results were compared with a traditional contact-cleaning approach; micro-vacuuming followed by sponging. Visual inspection, 3D opto-digital microscopy, colorimetry, and machine-learning-assisted (ML) soot counting were exploited for the assessment of cleaning efficacy. Rheological characterization provided information about the flexibility and handling properties of the different gel formulations. Among the tested systems, the DN gel containing only water, applied by tamping, was easy to handle and demonstrated the highest soot-removal effectiveness without leaving residues, as confirmed by micro-Fourier Transform Infrared (micro-FTIR) analysis. Scanning electron microscope (SEM) micrographs proved the structural integrity of the treated silk fibers. Overall, this work allows us to conclude that PVA–borax-based gels offer an effective, adaptable, and low-risk cleaning strategy for historical silk fabrics. Full article

Frequent crude oil spills during offshore oil and gas production and transportation have inflicted irreversible detrimental effects on both human activities and marine ecosystems; with particular risks of secondary disasters such as combustion and explosions. To address these challenges; advanced oil sorption technologies have been developed to overcome the inherent limitations of conventional remediation methods. In this study, a flame-retardant protective coating was fabricated on melamine sponge (MS) through precipitation polymerization of octa-aminopropyl polyhedral oligomeric silsesquioxane (POSS) and hexachlorocyclotriphosphazene (HCCP), endowing the MS@PPOS-PDMS-Si composite with exceptional char-forming capability. Secondary functional layer: By coupling the complementary physicochemical properties of polydimethylsiloxane (PDMS) and SiO₂ nanofibers, we enabled them to function jointly, achieving superior performance in the material systems; this conferred enhanced hydrophobicity and structural stability to the MS matrix. Characterization results demonstrated a progressive reduction in peak heat release rate (PHRR) from 137.66 kW/m² to118.35 kW/m², 91.92 kW/m², and ultimately 46.23 kW/m², accompanied by a decrease in total smoke production (TSP) from 1.62 m² to 0.76 m², indicating significant smoke suppression. Furthermore, the water contact angle (WCA) exhibited substantial improvement from 0° (superhydrophilic) to 140.7° (highly hydrophobic). Cyclic sorption–desorption testing revealed maintained oil–water separation efficiency exceeding 95% after 10 operational cycles. These findings position the MS@PPOS-PDMS-Si composite as a promising candidate for emergency oil spill response and marine pollution remediation applications, demonstrating superior performance in fire safety, environmental durability, and operational reusability. Full article

The discharge of synthetic dyes from industries poses severe environmental challenges, necessitating eco-friendly remediation strategies. This study investigated the biosorption of triarylmethane dyes Crystal Violet (CV), and Brilliant Green (BG) using self-immobilized and sponge-immobilized biosorbents of Trametes versicolor (strain CB8, CB8/S2) and Pleurotus ostreatus (strain BWPH, BWPH/S2). Tests were conducted with live and autoclaved biomass under varying conditions of dye concentration (100–400 mg/L), temperature (15–55 °C), and pH (2–10). Sponge-immobilized live biomass (CB8/S2 and BWPH/S2) showed superior performance, removing up to 90.3% and 81.7% of BG and 43.9% and 39.3% of CV, respectively, within 6 h, demonstrating 3–5 times higher efficiency than self-immobilized biomass for both dyes. Maximum sorption of 379.4 mg/g of BG and 48.9 mg/g of CV was achieved by CB8/S2 at 400 mg/L. Principal Component Analysis biplot confirmed immobilization efficacy, where Dim1 (85.9–91.8% variance) dominated dye concentration and contact time. The optimized conditions for BG removal by CB8/S2 was 20.85–32.17 °C and pH 3.4–6, and for CV, at pH 6.5–7.5 and 30 °C. The percentage of dye sorption data fitted well with the quadratic model (p < 0.05). Fourier transform infrared spectroscopy (FT-IR) analysis indicated that hydrogen bonding and electrostatic interactions facilitated dye binding onto fungal mycelium. Notably, sponge-immobilized biosorbents were reusable without additional treatment. The findings support fungal biomass immobilization as a viable strategy to augment the bioremediation potential in treating dye-laden wastewater. Full article

Chronic infected wounds remain a major medical challenge, particularly in the context of increasing antibiotic resistance. The objective of this study was to develop and evaluate chitosan-based (CS) sponges enhanced with graphene oxide (GO) as potential antimicrobial wound dressings. The composite sponges were fabricated using microcrystalline CS (MKCh) and 5% (w/w) GO, followed by freeze-drying and γ-sterilization (25 kGy). Physico-mechanical characterization showed that GO incorporation did not significantly alter tensile strength, while absorption and sorption capacities were improved, especially after sterilization. Structural and spectroscopic analyses confirmed increased porosity and molecular interaction between CS and GO. Cytocompatibility was verified in vitro using L-929 fibroblasts, with no cytotoxic effects observed in indirect contact. Antimicrobial activity tests demonstrated that GO-modified dressings exhibited enhanced activity against E. coli and S. aureus, though results were strain-dependent and not uniformly superior to CS alone. Notably, antifungal efficacy against C. albicans was reduced with GO addition. Overall, the developed GO-enriched CS sponges present favorable biocompatibility, mechanical resilience, and selective antimicrobial activity, supporting their potential application in chronic wound management. Further optimization of GO concentration and formulation is warranted to maximize antimicrobial efficacy across a broader spectrum of pathogens. Full article

In recent years, the use of non-invasive host and environmental samples for the detection and monitoring of equine respiratory pathogens has shown promise and a high overall agreement with the gold standard of nasal secretions. The present study looked at comparing nose wipes, stall sponges, and air samples with nasal swabs collected from 27 horses involved in an equine influenza (EI) outbreak. The outbreak involved 5 clinical, 6 subclinical, and 16 uninfected horses. Samples sets were collected at the onset of the index case and retested every 2–3 days thereafter until all horses tested qPCR-negative for EI virus (EIV). Nose wipes and stall sponges identified EIV in all clinical cases, and air samples identified EIV in 4/5 clinical horses. The overall agreement with all nasal swabs collected from clinical cases was 89% for nose wipes, 78% for stall sponges, and 44% for air samples. Due to the shorter shedding time in subclinical cases, nose wipes and stall sponges detected EIV in 5/6 and 4/6 subclinical horses, respectively. Only one single air sample tested qPCR-positive for EIV in a subclinical shedder. When compared to the gold standard of nasal secretions in subclinically infected horses, the overall agreement was 54% for stall sponges, 50% for air samples, and 45% for nose wipes. The collection of non-invasive contact and environmental samples is a promising alternative to nasal swabs for the detection of EIV in clinically and subclinically infected horses. However, they should always be considered as a second-choice sample type to the more accurate nasal swabs and used to test refractory horses or large populations during outbreaks. Further, the pooling of identical or different samples collected from the same horse for the qPCR testing of EIV increases the accuracy of detecting EIV, especially in subclinically infected horses. Full article

Background/Objectives: Considering the large number of candidates in vaccine-testing studies against different pathogens and the amount of time spent in the preclinical and clinical trials, there is a pressing need to develop an improved in vivo system to quickly screen vaccine candidates. The model of a polyester–polyurethane sponge implant provides a rapid analysis of the specific stimulus–response, allowing the study of a compartmentalized microenvironment. The sponge implant’s defined measurements were standardized as a compartment to assess the immune response triggered by the vaccinal antigen. The LBSap vaccine (composed of Leishmania braziliensis antigens associated with saponin adjuvant) was used in the sponge model to assess the antigen-specific immunological biomarker, including memory generation after initial contact with the antigen. Methods: Mice strains (Swiss, BALB/c, and C57BL/6) were previously immunized using LBSap vaccine, followed by an antigenic booster performed inside the sponge implant. The sponge implants were assessed after 72 h, and the immune response pattern was analyzed according to leukocyte immunophenotyping and cytokine production. Results: After LBSap vaccination, the innate immune response of the antigenic booster in the sponge implants demonstrated higher levels in the Ly+ neutrophils and CD11c+ dendritic cells with reduced numbers of F4/80+ macrophages. Moreover, the adaptive immune response in Swiss mice demonstrated a high CD3+CD4+ T-cell frequency, consisting of an effector memory component, in addition to a cytoxicity response (CD3+CD8+ T cells), displaying the central memory biomarker. The major cell surface biomarker in the BALB/c mice strain was related to CD3+CD4+ effector memory, while the increased CD3+CD8+ effector memory was highlighted in C57/BL6. The cytokine profile was more inflammatory in Swiss mice, with the highest levels of IL-6, TNF, IFN-g, and IL-17, while the same cytokine was observed in in C57BL/6 yet modulated by enhanced IL-10 levels. Similar to Swiss mice, BALB/c mice triggered an inflammatory environment after the antigenic booster in the sponge implant with the increased levels in the ILL-6, TNF, and IFN-g. Conclusions: The findings emphasized the impact of genetic background on the populations engaged in immune responses, suggesting that this model can be utilized to enhance and track both innate and adaptive immune responses in vaccine candidates. Consequently, these results may inform the selection of the most suitable experimental model for biomolecule testing, taking into account how the unique characteristics of each mouse strain affect the immune response dynamics. Full article

Background: It is well known that periodontitis affects the gums and surrounding connective tissue. The chronic inflammatory response induced by bacteria in the gingival tissue leads to the loss of the collagen connection between the tooth and the bone and ultimately to bone loss. Methods: In this context, the aim of this research was the obtaining and characterization of a drug release supports in the form of sponges based on collagen, hyaluronic acid as a support and metronidazole as an antibiotic for the treatment of periodontitis. The sponges were characterized by FT-IR spectroscopy, water uptake, contact angle, SEM microscopy, in vitro metronidazole release analysis from sponges and data modeling. Results: The results showed that all the sponges had a porous structure with interconnected pores, the pore sizes being influenced by hyaluronic acid and metronidazole; the spongious structure became much more dense for samples with metronidazole content. All metronidazole-loaded sponges showed good surface wettability and an adequate swelling capacity for a suitable antimicrobial release at the periodontal pocket. The porous structures allow a controlled release, fast in the first hour, essential to control the initial microbial load at the periodontal level, which continues slowly in the following hours to ensure an effective treatment of periodontitis. Conclusions: Correlating all physical–chemical and bio-pharmaceutical results obtained, a promising solution for periodontitis treatment could be a met-ronidazole–collagen–hyaluronic system consisting of 1% collagen, 1.5% metronidazole and 0.8% hyaluronic acid, and in vitro and in vivo tests are recommended to continue studies. Full article

In populations of healthy show horses, the subclinical transmission and circulation of respiratory pathogens can lead to disease outbreaks. Due to recent outbreaks of equine herpesvirus-1 myeloencephalopathy (EHM) in the USA and Europe, many show organizers have instituted various biosecurity protocols such as individual horse testing, monitoring for early clinical disease and increasing hygiene and cleanliness protocols. The aim of this study was to determine the accuracy of detecting EHV-1 in the various environmental samples collected from the stalls of subclinical shedders. Four healthy adult horses were vaccinated intranasally with a modified-live EHV-1 vaccine in order to mimic subclinical shedding. Three additional horses served as non-vaccinated controls. All the horses were stabled in the same barn in individual stalls. Each vaccinated horse had nose-to-nose contact with at least one other horse. Prior to the vaccine administration, and daily thereafter for 10 days, various samples were collected, including a 6” rayon-tipped nasal swab, an environmental sponge, a cloth strip placed above the automatic waterer and an air sample. The various samples were processed for nucleic acid purification and analyzed for the presence of EHV-1 via quantitative PCR (qPCR). EHV-1 in nasal secretions was only detected in the vaccinated horses for 1–2 days post-vaccine administration. The environmental sponges tested EHV-1 qPCR-positive for 2–5 days (median 3.5 days) in the vaccinated horses and 1 day for a single control horse. EHV-1 was detected by qPCR in stall strips from three out of four vaccinated horses and from two out of three controls for only one day. EHV-1 qPCR-positive air samples were only detected in three out of four vaccinated horses for one single day. For the vaccinated horses, a total of 25% of the nasal swabs, 35% of the environmental stall sponges, 7.5% of the strips and 7.5% of the air samples tested qPCR positive for EHV-1 during the 10 study days. When monitoring the subclinical EHV-1 shedders, the collection and testing of the environmental sponges were able to detect EHV-1 in the environment with greater frequency as compared to nasal swabs, stationary strips and air samples. Full article

The major problems related to environmental pollution are increasingly present among us. The uncontrolled use and incorrect disposal of products means that these problems are increasing at frightening rates. In this context, a major related problem is the incorrect disposal of dishwasher sponges that are no longer useful; their material being made up of petroleum derivatives causes this problem to be leveraged in the environment. In the present work, we evaluated and carried out tests in which these dirty sponges that would be discarded were used for the purpose of developing new sustainable adsorbent materials. These materials were washed and dried, crushed and made available for use, by which they were kept in contact with a paracetamol solution, evaluating the effect of mass, pH, kinetics, equilibrium, thermodynamic parameters, and cost analyses. The results demonstrated an adsorptive capacity of approximately 40 mg g⁻¹ and its cost was relatively viable, since this material would otherwise be discarded incorrectly. In conclusion, this material achieved the good removal of this studied contaminant and became an economical, viable, and ecologically viable material. Full article

The present study investigated the in vivo bone-forming efficacy of an innovative titanium (Ti) dental implant combined with a collagen sponge containing recombinant human bone morphogenetic protein-2 (BMP-2) in a pig model. Two different concentrations of BMP-2 (20 and 40 µg/mL) were incorporated into collagen sponges and placed at the bottom of Ti dental implants. The investigated implants were inserted into the edentulous ridge at the canine–premolar regions of Lanyu small-ear pigs, which were then euthanized at weeks 1, 2, 4, 8, and 12 post-implantation. Specimens containing the implants and surrounding bone tissue were collected for histological evaluation of their bone-to-implant contact (BIC) ratios and calculation of maximum torques using removal torque measurement. Analytical results showed that the control and BMP-2-loaded implants presented good implant stability and bone healing for all testing durations. After 1 week of healing, the BMP-2-loaded implants with a concentration of 20 µg/mL exhibited the highest BIC ratios, ranging from 58% to 76%, among all groups (p = 0.034). Additionally, they also possessed the highest removal torque values (50.1 ± 1.3 N-cm) throughout the 8-week healing period. The BMP-2-loaded implants not only displayed excellent in vivo biocompatibility but also presented superior osteoinductive performance. Therefore, these findings demonstrate that BMP-2 delivered through a collagen sponge can potentially enhance the early-stage osseointegration of Ti dental implants. Full article

Nature provides various templates for integrating organic and inorganic materials to create high-performance composites. Biological structures such as nacre and the structural elements of the glass sponge are built up in layers, leading to remarkable fracture toughness. In this work, the brick-and-mortar and layer-by-layer structures found in these biological examples have been abstracted and implemented by using an aqueous polymer dispersion in combination with nanoclay particles and sodium water glass. These dispersions were used as impregnation of carbon rovings in order to form bio-inspired contact zones towards the concrete matrix. The bonding behavior was investigated using the Yarn Pull-Out (YPO) test, and a beneficial behavior of the layered polymer–nanoclay dispersions was observed. Thermogravimetric analysis (TGA) was used to determine the organic impregnation content of the roving. Further, light microscopy of the roving cross-sections prior to YPO and visual analyses of the fractured contact zone of split concrete specimens provided information on the quality of the impregnation and the interaction with the concrete matrix. Full article

In this study, we fabricated three dimensional (3D) porous scaffolds of poly(hydroxybutyrate-co-hydroxyvalerate) with 50% HV content. P(HB-50HV) was biosynthesized from bacteria Cupriavidus necator H16 and the in vitro proliferation of dental cells for tissue engineering application was evaluated. Comparisons were made with scaffolds prepared by poly(hydroxybutyrate) (PHB), poly(hydroxybutyrate-co-12%hydroxyvalerate) (P(HB-12HV)), and polycaprolactone (PCL). The water contact angle results indicated a hydrophobic character for all polymeric films. All fabricated scaffolds exhibited a high porosity of 90% with a sponge-like appearance. The P(HB-50HV) scaffolds were distinctively different in compressive modulus and was the material with the lowest stiffness among all scaffolds tested between the dry and wet conditions. The human gingival fibroblasts (HGFs) and periodontal ligament stem cells (PDLSCs) cultured onto the P(HB-50HV) scaffold adhered to the scaffold and exhibited the highest proliferation with a healthy morphology, demonstrating excellent cell compatibility with P(HB-50HV) scaffolds. These results indicate that the P(HB-50HV) scaffold could be applied as a biomaterial for periodontal tissue engineering and stem cell applications. Full article

In this study, PVDF/GO-h composite membranes were synthesised using a homogeniser to improve the dispersion of GO nanosheets within the composite membrane’s structure, and then characterised and contrasted to PVDF/GO-s control samples, which were synthesised via traditional blending method-implementing a magnetic stirrer. By characterizing membrane via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), water contact angle (WCA) and membrane performance. SEM results showed that the number of the finger-like structure channels and pores in the sponge like structure of PVDF/GO-h composite membranes become more compared with PVDF/GO-s membranes. Water contact angle tests showed that the PVDF/GO-h composite membranes have lower contact angle than PVDF/GO-s control, which indicated the PVDF/GO-h composite membranes are more hydrophilic. Results also showed that composite membranes blended using homogeniser exhibited both improved water flux and rejection of target pollutants. In summary, it was shown that the performance of composite membranes could be improved significantly via homogenisation during synthesis, thus outlining the importance of further research into proper mixing. Full article

Oil leaks (or spills) into the aquatic environment are considered a natural disaster and a severe environmental problem for the entire planet. Samples of polyurethane (PU) composites were prepared with high specific surface area carbon nanotubes (CNT) to investigate crude oil sorption. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), density measurements, and mechanical compression tests were used to characterize the polyurethane-carbon PU–CNT prepared samples. The spongy composites exhibited good mechanical behavior and a contact angle of up to 119°. The oleophilic character resulted in increased hydrophobicity, a homogeneous oil distribution inside the sponge, and a sorption capacity in a water/oil mixture of 41.82 g/g. Stress-strain curves of the prepared samples showed the good mechanical properties of the sponge, which maintained its stability after more than six sorption desorption cycles. The CNT–PU composites may prove very effective in solving oil pollution problems. Full article