Fluid Absorption Research Articles

Thai Novel Cost-Effectiveness Biocellulose Dressing: Clinical Trial Phase I, Randomized Controlled Trial

Background: Biocellulose wound dressings offer flexibility, high tensile strength, and water-retention properties, resulting in a cool and painless dressing experience. However, their usage has been limited due to high costs. In 2020, the PTT Research and Development Department introduced “Innaqua®,” a novel biocellulose wound dressing that excels in fluid absorption capacity, desorption, wound dressing surface, and wound moisturization. This product is particularly suitable for developing countries, as it combines low cost with high effectiveness, thereby enhancing treatment accessibility. However, it lacks clinical studies. Objective: To evaluate the clinical safety of Innaqua® for human use. Materials and Methods: A randomized controlled trial, clinical safety study was conducted with 63 healthy volunteers. Skin irritation and allergic reactions were analyzed. Results: Clinical safety studies of Innaqua® indicated non-inferiority in terms of erythema at 4.8% versus 4.8% (p=0.012) and allergic reactions at 3.2% versus 4.8% (p=0.004) compared with Bactigras®. No edema occurred with either wound dressing. Conclusion: Innaqua® is a biocellulose wound dressing researched and developed in Thailand. It creates an optimal environment for wounds. The present study demonstrated clinical safety in human use. Innaqua® emerges as a new, cost-effective option for biocellulose wound dressing, catering to a broader population. Keywords: Biocellulose; Innaqua; Thai; Allergy; Safety

Biodegradation and Thermomechanical Behavior of 3D-Printed PLA Scaffolds Under Static and Stirring Biomimetic Conditions

3D-printed biomedical polylactic acid (PLA) scaffolds were developed, and their biodegradation, as well as their thermomechanical behavior, were studied in a relevant in vitro environment. The scaffold’s biodegradability profile has been monitored after immersion in a cell culture medium that contains components of blood and body fluids. Two types of biodegradation experiments were performed—a standard static one and an adapted stirring one, mimicking the body fluids’ flow, respectively—to achieve a comparative investigation. The biodegradation experiment’s duration was one month. The measurements were performed between days 1 and 28. The scaffold microstructure was analyzed with scanning electron microscopy (SEM). The weight loss of the scaffolds has been monitored. Differential scanning calorimetry (DSC) has been used to evaluate the glass transition temperature (Tg) of the scaffolds and to draw useful conclusions about their thermal behavior. Finally, dynamic mechanical analysis (DMA) was applied to investigate the viscoelastic behavior of the samples. The SEM analysis demonstrated that the samples in a static experiment are more damaged, while those in the stirring experiment are more brittle. The maximum Tg value of the material measured by DSC is around 65 °C. This value is reached after 5 days of immersion in static conditions and after 14 days of immersion after stirring, indicating that some processes take place faster in the static experiment. The variation of the Tg vs. immersion time, as derived from DSC vs. DMA measurements, gives similar results for both static and fluid absorption conditions, demonstrating the reproducibility of the results.

Influence of water-repellent admixtures ( Sitren and Stearate materials) on the microstructure and mechanical performance of conventional Portland cement paste and mortar

The longevity of mortar and concrete structures can be compromised by the absorption of water and other fluids, leading to deterioration and aesthetic issues. To address this, water-repellent admixtures are employed to enhance the service life of mortar and concrete components by improving their mechanical and microstructural characteristics. This study focus on the effects of incorporating Sitren P 750 and various stearate materials (calcium, zinc, aluminum, and barium) as admixtures with ordinary Portland cement at mortar and paste dosages of 0.5%, 1.0%, and 1.5% of the cement content. We found that mortars with water-repellent admixtures exhibited competitive mechanical properties at all curing ages. Additionally, the study confirmed the contribution of these admixtures to the production of hydration products and the structural development of the mortars, as investigated through scanning electron microscopy, thermogravimetric–derivative thermogravimetric, and X-ray diffraction analyses. Despite alterations in several physical properties and hydration kinetics due to the water-repellent compounds and their dosages, all admixtures provided effective water-repellent protection. This was further corroborated by water contact angle tests and the measurement of the capillary water absorption coefficient for all samples. Identifying the optimal mixture ratio for construction technology and effectively incorporating repellence features is a crucial aspect of this research.

Highly Performing Polysaccharide Hydrogels can Replace Acrylic Acid‐Based Superabsorbent Polymers in Sanitary Napkins

AbstractSuper absorbent polymers (SAPs) used in sanitary napkin are not required for water absorption capacity as high as in baby diapers and adult incontinence pads. Sanitary napkins must absorb menses, which is delivered at a significantly lower rate and overall daily amount than urines. Thus, the acrylic acid (AA) component can not be strictly necessary. By proper formulation design and processing, polysaccharide SAPs can be equally or even better performing than AA‐containing SAPs in sanitary napkins. Fully biodegradable sodium alginate (SA)‐based SAPs are prepared through ionic cross‐linking by CaCl2 and introduced in female pads. The optimal solution concentrations (SA 8% w/v, CaCl2 0.25% w/v in water) and reaction time are identified, and addition of cellulose nanocrystals (CNC) at different weight contents (0–3 w%) is tested. Morphology, physico‐chemical properties, rheology, free swelling capacity (FSC), centrifuge retention capacity, and weight loss in soil are assessed. Increasing CNC content decreases FSC. Rheology results demonstrate higher storage and loss moduli for SA‐based SAPs versus commercial SAPs. The superior SA‐SAP developed is used in varying amounts for manufacturing sanitary napkin prototypes, revealing that excellent menstrual fluid absorption, surpassing commercial pads. Replacing AA‐based with polysaccharide‐based SAPs would reduce the environmental impact of hygienic product waste.

Carbonic anhydrase inhibitor alleviates retinal barrier toxicity in paclitaxel-induced retinopathy and macular edema by inhibiting CAXIV

PurposeTo investigate the mechanism of paclitaxel (PTX)-induced macular edema and the therapeutic effect of carbonic anhydrase inhibitors (CAI) on this condition.MethodsThe effect of PTX on cell morphology was detected by immunofluorescence. Cell barrier was measured by measuring cell resistance across the epithelium. Western blotting analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to investigate the effects of PTX or PTX + CAI on the expression of carbonic anhydrase XIV (CAXIV), aquaporin 4 (AQP4) and inflammatory factors. After intraperitoneal injection of PTX in vivo, retinal electrophysiology (ERG) was used to evaluate the effects of drugs on visual electrophysiology.ResultsPTX inhibited the proliferation of ARPE-19 and Müller cells, promoting their apoptosis, changing their morphology and cell cycle, reducing the transepithelial resistance of ARPE-19 cells and promoting the expression of inflammatory factors; This process was alleviated after temporary withdrawal. CAI inhibited the upregulation of inflammatory factors. Following treatment with PTX, the expression levels of AQP4 and CAXIV were higher than control group; nevertheless, the levels of ZO-1 and OCLN were lower than control group. In vivo, the ERG analysis showed that the light- and dark-adapted 3.0 ERG, and dark-adapted 3.0 oscillatory potentials decreased to different degrees following treatment with PTX.ConclusionPTX-induced macular edema is mainly due to Müller cell toxicity. The condition can be alleviated by regulating water channels and enhancing subretinal fluid absorption. Thus, CAI may provide a new therapeutic approach for PTX-induced macular edema.

Blood osmolytes such as sugar can drive brain fluid flows in a poroelastic model

The glymphatic system of fluid flow through brain tissue may clear amyloid-β during sleep and as such underlie the need for sleep. Dysfunctional glymphatic transport has been implicated in pathological conditions ranging from stroke and dementia to psychiatric illnesses. To date, the fastest observed in-vivo brain flows have been reported after the manipulation of blood osmotic pressures. Surprisingly, the brain seems to shrink while receiving more influx. Though influx of an incompressible fluid might expand the tissue, no physical theory for these observations has been proposed. We here present a minimal mathematical model of brain pressure, deformation, and fluid flows due to vascular osmotic pressures. The model is based on Darcy flow, linear poroelasticity theory and conservation of mass. We propose that a screened Poisson equation holds for interstitial pressure because vascular filtration corresponds to fluid divergence. The model resolves the apparent paradox of combined fluid influx with tissue shrinkage by showing that fluid absorption into the blood can drive both. In this model, small glucose concentration differences between plasma and brain can drive brain flow velocities observed in recent in-vivo assays. Osmosis may therefore drive brain fluid flow under physiological conditions and provide an explanation for the known correlations between diabetes and dementia.

Pulsed peritoneal dialysis in an experimental rat model: A first experience.

Peritoneal dialysis (PD) is commonly performed using either intermittent or tidal exchanges, whereas other exchange techniques such as continuous flow PD are little used. Previous research indicated that stirring the intra-peritoneal dialysate markedly increases small solute clearances. Here, we tested the hypothesis that stirring of the dialysate increases small solute clearances by using a novel exchange technique where the dialysate is pulsed back and forth during the treatment without addition of fresh fluid. PD was performed in anesthetized Sprague-Dawley rats with either no pulsations (20 mL fill volume), 2 mL (10%) pulses (21 mL fill volume), or 5 mL (25%) pulses (22.5 mL fill volume) utilizing a pulse flow rate of 5 mL/min. The higher fill volume for the pulsed treatments compensates for the fact that the average intra-peritoneal volume would otherwise be lower in pulsed treatments. Water and solute transport were closely monitored during the treatment. Net ultrafiltration decreased significantly during pulsed PD with the 25% pulse volume. The 60 min sodium dip was unaltered, whereas the fluid absorption rate was increased for the 25% group. Solute clearances did not significantly differ between groups, except for a slightly lower calcium clearance in the 25% group. Our data indicate that stirring the dialysate using pulsed exchanges does not provide any advantage compared to conventional exchange techniques. In contrast, pulsed treatments had slightly lower ultrafiltration and small solute transport. The present findings may have implications regarding the choice of tidal volume in automated PD, favoring smaller tidal volumes.

Biocompatible nanocomposite hydroxyapatite-based granules with increased specific surface area and bioresorbability for bone regenerative medicine applications

Hydroxyapatite (HA) granules are frequently used in orthopedics and maxillofacial surgeries to fill bone defects and stimulate the regeneration process. Optimal HA granules should have high biocompatibility, high microporosity and/or mesoporosity, and high specific surface area (SSA), which are essential for their bioabsorbability, high bioactivity (ability to form apatite layer on their surfaces) and good osseointegration with the host tissue. Commercially available HA granules that are sintered at high temperatures (≥ 900 °C) are biocompatible but show low porosity and SSA (2–5 m2/g), reduced bioactivity, poor solubility and thereby, low bioabsorbability. HA granules of high microporosity and SSA can be produced by applying low sintering temperatures (below 900 °C). Nevertheless, although HA sintered at low temperatures shows significantly higher SSA (10–60 m2/g) and improved bioabsorbability, it also exhibits high ion reactivity and cytotoxicity under in vitro conditions. The latter is due to the presence of reaction by-products. Thus, the aim of this study was to fabricate novel biomaterials in the form of granules, composed of hydroxyapatite nanopowder sintered at a high temperature (1100 °C) and a biopolymer matrix: chitosan/agarose or chitosan/β-1,3-glucan (curdlan). It was hypothesized that appropriately selected ingredients would ensure high biocompatibility and microstructural properties comparable to HA sintered at low temperatures. Synthesized granules were subjected to the evaluation of their biological, microstructural, physicochemical, and mechanical properties. The obtained results showed that the developed nanocomposite granules were characterized by a lack of cytotoxicity towards both mouse preosteoblasts and normal human fetal osteoblasts, and supported cell adhesion to their surface. Moreover, produced biomaterials had the ability to induce precipitation of apatite crystals after immersion in simulated body fluid, which, combined with high biocompatibility, should ensure good osseointegration after implantation. Additionally, nanocomposite granules possessed microstructural parameters similar to HA sintered at a low temperature (porosity approx. 50%, SSA approx. 30 m²/g), Young’s modulus (5–8 GPa) comparable to cancellous bone, and high fluid absorption capacity. Moreover, the nanocomposites were prone to biodegradation under the influence of enzymatic solution and in an acidic environment. Additionally, it was noted that the hydroxyapatite nanoparticles remaining after the physicochemical dissolution of the biomaterial were easily phagocytosed by mouse macrophages, mouse preosteoblasts, and normal human fetal osteoblasts (in vitro studies). The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability. The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability.

Light-sensitive Ca2+ signaling in the mammalian choroid

The choroid is the thin, vasculature-filled layer of the eye situated between the sclera and the retina, where it serves the metabolic needs of the light-sensing photoreceptors in the retina. Illumination of the interior surface of the back of the eye (fundus) is a critical regulator of subretinal fluid homeostasis, which determines the overall shape of the eye, but it is also important for choroidal perfusion. Noted for having some of the highest blood flow rates in the body, the choroidal vasculature has been reported to lack intrinsic, intravascular pressure-induced (myogenic) autoregulatory mechanisms. Here, we ask how light directly regulates choroid perfusion and ocular fluid homeostasis, testing the hypothesis that light facilitates ocular fluid absorption by directly increasing choroid endothelial permeability and decreasing choroid perfusion. Utilizing ex vivo pressurized whole-choroid and whole-eye preparations from mice expressing cell-specific Ca2+ indicators, we found that the choroidal vasculature has two intrinsically light-sensitive Ca2+-signaling mechanisms: One increases Ca2+-dependent production of nitric oxide in choroidal endothelial cells; the other promotes vasoconstriction through Ca2+ elevation in vascular smooth muscle cells. In addition, we found that choroidal flow, or pressure, modulates endothelial and smooth muscle photosensitivity and trans-retinal absorption of fluid into the choroid. These results collectively suggest that the choroid vasculature exhibits an inverted form of autoregulatory control, where pressure- and light-induced mechanisms work in opposition to regulate blood flow and maintain fluid balance in response to changes in light and dark, aligning with the metabolic needs of photoreceptors.

Schiff-Base Cross-Linked Hydrogels Based on Properly Synthesized Poly(ether urethane)s as Potential Drug Delivery Vehicles in the Biomedical Field: Design and Characterization.

In situ-forming hydrogels based on the Schiff-base chemistry are promising for drug delivery applications, thanks to their stability under physiological conditions, injectability, self-healing properties, and pH-responsiveness. In this work, two water-soluble poly(ethylene glycol)-based poly(ether urethane)s (PEUs) were engineered. A high-molecular-weight PEU (SHE3350, M̅ n 24 kDa, D 1.7), bearing primary amino groups along each polymeric chain, was synthesized using N-Boc serinol and subjected to an acidic treatment to expose primary amines (ca. 1020 units/gSHE3350). In parallel, a low-molecular-weight PEU (AHE1500, M̅ n 4 kDa, D 1.5) with aldehyde end groups was synthesized by end-capping an isocyanate-terminated prepolymer with 4-hydroxybenzaldehyde, and the aldehyde groups were quantified to be around 1020 units/gAHE1500. Hydrogels were prepared by simply mixing SHE3350 and AHE1500 aqueous solutions and characterized to assess their physico-chemical and rheological properties. Schiff-base bond formation was proved through carbon-13 and proton solid-state NMR spectroscopies. Rheological characterization confirmed the formation of gels with high resistance to applied strain (ca. 1000%). Hydrogels exhibited high absorption ability (ca. 270% increase in wet weight) in physiological-like conditions (i.e., 37 °C and pH 7.4) up to 27 days. In contact with buffer at pH 5, enhanced fluid absorption was observed until dissolution occurred starting from 13 days due to Schiff-base hydrolysis in acidic conditions. Conversely, gels showed a reduced absorption ability at pH 9 due to shrinkage phenomena. Furthermore, they exhibited high permeability and controlled, sustained, and pH-triggered release of a model molecule (i.e., fluorescein isothiocyanate dextran) for up to 17 days. Lastly, the hydrogels showed easy injectability and self-healing ability.

Transport functions of intestinal lymphatic vessels.

Lymphatic vessels are crucial for fluid absorption and the transport of peripheral immune cells to lymph nodes. However, in the small intestine, the lymphatic fluid is rich in diet-derived lipids incorporated into chylomicrons and gut-specific immune cells. Thus, intestinal lymphatic vessels have evolved to handle these unique cargoes and are critical for systemic dietary lipid delivery and metabolism. This Review covers mechanisms of lipid absorption from epithelial cells to the lymphatics as well as unique features of the gut microenvironment that affect these functions. Moreover, we discuss details of the intestinal lymphatics in gut immune cell trafficking and insights into the role of inter-organ communication. Lastly, we highlight the particularities of fat absorption that can be harnessed for efficient lipid-soluble drug distribution for novel therapies, including the ability of chylomicron-associated drugs to bypass first-pass liver metabolism for systemic delivery. In all, this Review will help to promote an understanding of intestinal lymphatic-systemicinteractionsto guide future research directions.

Pathophysiology of Normal Pressure Hydrocephalus

The current perspective for the pathophysiology of normal pressure hydrocephalus is focusing on stiffness of the central nervous tissue, especially on a type of cerebrovascular disorder. Rigid intracranial vessels and tissues derived by either vascular risk factors or aging may lead into impaired dynamics of the cerebrospinal fluid such as increased pulsatility and decreased absorption of the cerebrospinal fluid. Enlarged ventricle may result in a decrease of blood perfusion in brain parenchyma, and in turn global hypoxia and neuro-inflammation along with a breakdown of the blood-brain-barrier. Deterioration of the glymphatic pathway, the crucial disposal pathway of the waste product of the brain, also might contribute to the irreversible injury of the nervous tissue by deposition of abnormal toxic proteins including amyloid beta. Of note, the pathophysiology of the normal pressure hydrocephalus is moving to a type of cerebrovascular disorder instead of the etiology of idiopathic.

Elastic and recoverable sponges based on collagen/yeast β-glucan for quick hemostasis

In this investigation, we aimed to engineer sponges with exceptional mechanical and hemostatic capabilities for effective wound healing. By combining collagen, a stiff fibril protein in ECM, with β-glucan, an elastic and triple-helical polysaccharide from yeast cell wall, we prepared a series of composite sponges, designated as CY sponges. This material exhibited a uniform pore structure, displaying enhanced elasticity and shape recovery ability compared to pure collagen sponges. Also, the incorporation of Yeast β-glucan (YG) significantly improved the fluid absorption ability and stability of the sponges. In vitro hemostasis tests demonstrated that the CY sponges exhibited a notably lower in vitro coagulation index (19.21 %) compared to the collagen control (64.84 %), accompanied by superior erythrocyte (64.64 %) and platelet (64.95 %) adhesion properties. Animal studies further substantiated the sponge's hemostatic efficacy, as CY40 led to a reduction in average bleeding volume by 25.26 % and 28.97 %, and a shorter hemostatic time by 31.70 % and 30.77 % compared to collagen, indicating accelerated wound healing. These findings suggest that the addition of yeast β-glucan into collagen sponges can improve their elasticity, shape recovery ability, hemostatic performance and wound repair ability.

Enhancing Surgical Care: Development of Biocompatible, Superabsorbent Alternatives to Cotton Gauze Using Chia Mucilage and Poly(vinylpyrrolidone).

Cotton gauze bandages have traditionally played a pivotal role in wound care and surgical procedures, absorbing fluids, including blood, and protecting against infection. However, their limited liquid absorption capacity raises concern about potential post-surgery complications if inadvertently retained. In response, resorbable and biocompatible polymers have emerged as a promising alternative to enhance surgical outcomes and mitigate inflammation. This study aims to develop a biocompatible, highly absorbent, and preferably resorbable substitute for cotton gauze, utilizing natural polysaccharides from chia seeds' mucilage alongside the synthetic polymer poly(vinylpyrrolidone) (PVP). Incorporating tranexamic acid, an antifibrinolytic agent, into the PVP solution enhances its efficacy in controlling blood flow. The polymer solution is then processed into nonwoven materials via solution blow spinning. UV-C radiation cross-linking is employed to bolster the nonwovens' performance and durability during liquid absorption and swelling. Results demonstrate that nonwoven samples comprising PVP and chia mucilage, cross-linked for 60 min with UV-C radiation, exhibit exceptional swelling capacity, absorbing approximately 3291% of their dry weight in saline solution. Microfiber analysis indicates alterations in fiber characteristics due to cross-linking duration. Cell viability tests affirm the biocompatibility of the produced materials. With their remarkable fluid absorption properties and potential for resorption, PVP/chia mucilage compositions supplemented with tranexamic acid offer a promising avenue for effectively managing surgical bleeding without adverse effects. Furthermore, these materials can safely remain within the surgical site, eventually undergoing natural resorption by the body owing to their resorbable nature.

Treatment Options in Bilateral Diffuse Uveal Melanocytic Proliferation (BDUMP): Case Presentation and Review of the Literature

ABSTRACT Purpose To outline the therapeutic approach for a rare case of Bilateral Diffuse Uveal Melanocytic Proliferation (BDUMP) and examine the current management recommendations of this uncommon condition. Methods-Results Literature review on the current treatment options in BDUMP cases. An 82-year-old woman was referred to our clinic due to bilateral visual loss. She was treated elsewhere with anti-vascular endothelial growth factors (anti-VEGF) in both eyes for presumed choroidal neovascularization (CNV) without improvement. Her past medical history (PMH) entailed colon cancer, treated with surgical resection and adjuvant chemotherapy 15 years ago. The patient presented with low visual acuity in both eyes, multiple oval orange patches in the fundus with striking hyperfluorescent pattern in fluorescein angiography (FA), giraffe pattern in fundus autofluorescence (FAF) and rapidly progressive cataracts. Intravitreal dexamethasone implants were administered with mild improvement and subretinal fluid absorption. Conclusions The management strategy in BDUMP should focus on the systemic, often occult malignancy. There is no standard treatment protocol for BDUMP; however, plasmapheresis in combination with primary malignancy treatment seems to yield promising results in current literature reports. Anti-VEGF injections failed to control BDUMP sequelae, however intravitreal dexamethasone implants may offer temporary relief.

Evaluating sisal fibers as an eco-friendly and cost-efficient alternative to cotton for the Moroccan absorbent hygiene and textile industries

The Moroccan textile and hygiene industries face challenges related to the cost and availability of imported cotton fibers, prompting the exploration of alternative and sustainable solutions. The goal was to replace cotton, which presented a significant challenge for the sector, while maintaining its quality properties. This study aimed to replace the imported cotton fibers in Morocco with sisal fibers, a locally available, cheaper, and durable product that exhibits satisfactory physicochemical properties. To achieve this, sisal fibers were treated with different concentrations of sodium hydroxide (NaOH), sodium chlorite (NaClO₂), and hydrogen peroxide (H₂O₂). Analytical techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Optical Microscopy (OM), and X-ray Diffraction (XRD), were used to assess both sisal and commercial cotton fibers. Laboratory tests, such as pH measurements, water absorption, flammability, and degumming rate, were conducted to evaluate and compare their properties. Among the sisal samples analyzed, those treated with 10 % by weight (wt) NaOH and bleached with NaClO₂ showed satisfactory results. These fibers exhibited a compliant pH, a chemical structure similar to cotton, reduced fiber size, a type I crystal structure with a 0.36 crystallinity index, and improved thermal stability. Additionally, they presented a whitish appearance, softness similar to cotton, good fluid absorption capacity, and flame resistance. This study concluded that cotton fibers can be substituted with sisal fibers in the textile and hygiene industries. Further comprehensive analyses could expand the applicability of sisal fibers to additional sectors.

Evaluation of changes in Mallampati grading in patients undergoing elective urological procedures in prone and lithotomy positions- A prospective observational study

Intubation often results in airway edema, which can lead to reintubation following planned extubation in the post-anesthesia care unit. In urological procedures like percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL), the use of irrigation fluids may exacerbate these airway changes. This study aims to assess alterations in Mallampati grading in patients undergoing elective urological procedures, particularly in prone and lithotomy positions.This prospective observational study was conducted at a tertiary care hospital from May 2021 to September 2021. Sixty patients with ASA I and II classifications scheduled for elective PCNL in the prone position and URSL in the lithotomy position, with 30 patients in each group, were enrolled. We assessed the Modified Mallampati Grading (MPG) before the procedure and at postoperative intervals of 4 h, 8 h, 12 h, 24 h, and 48 h, noting any changes and the time required to return to the baseline. We also recorded the number of irrigation fluids used, intravenous (IV) fluids administered, surgery duration, and estimated blood loss to explore potential associations.MPG changed by at least one class in 36.6 % of patients in the prone position and 20 % of patients in the lithotomy position. Furthermore, MPG changed by two classes in 20 % of patients in the prone position and 3.3 % of patients in the lithotomy position. The absorption of irrigation fluids was identified as a potential cause of airway edema, with a significant p-value of 0.0001, leading to worsening of the MPG. Fortunately, in most patients, the changes in MPG returned to baseline values within 24 h.In conclusion, our study confirms that Mallampati grading may experience at least a one-class increase in both prone and lithotomy positions in most patients, and it typically reverts to baseline in about 24 h for most patients. These airway changes should be considered when re-intubating patients in the postoperative period.

A novel technique for measurement of fluid absorption during ureteroscopy.

A novel technique for measurement of fluid absorption during ureteroscopy.

Effect of wound dressing porosity and exudate viscosity on the exudate absorption: In vitro and in silico tests with 3D printed hydrogels

Exudate absorption is a key parameter for proper wound dressing performance. Unlike standardized tests that consider exudate viscosity close to that of water, patients' exudates vary greatly in composition and, therefore, viscosity. This work aimed to investigate the effects of exudate viscosity and pore size of hydrogel-like dressings on the exudate absorption rate to establish rational criteria for the design of dressings that can meet the personalized needs of wound treatment. Computer-aided design (CAD) was used for Digital Light Processing (DLP) 3D printing of hydrogels with 0%, 30% and 60% porosity. The hydrogels were characterized in detail, and the absorption of two simulated exudate fluids (SEFs) was video-recorded. The same CAD files were used to develop in silico models to simulate exudate uptake rate. Both in vitro data and in silico modeling revealed that low-viscosity SEF penetrates faster through relatively small hydrogel pores (approx. 400 μm) compared to larger pores (approx. 1100 μm) due to capillary forces. However, in vitro vertical uptake took longer than when simulated using CAD design due to lateral fluid absorption through the pore walls in the hydrogel bulk. Distortions of hydrogel channels (micro-CT images) and lateral fluid absorption should be both considered for in silico simulation of SEF penetration. Overall, the results evidenced that porous hydrogel dressings allow rapid penetration (within a few seconds) and hosting of exudates, especially for pore size <1 mm. This information may be useful for design criteria of wound dressings with adequate fluid handling and drug release rate.

Development of Halloysite Nanohybrids-Based Films: Enhancing Mechanical and Hydrophilic Properties for Wound Healing.

Most of the therapeutic systems developed for managing chronic skin wounds lack adequate mechanical and hydration properties, primarily because they rely on a single component. This study addresses this issue by combining organic and inorganic materials to obtain hybrid films with enhanced mechanical behavior, adhesion, and fluid absorption properties. To that aim, chitosan/hydrolyzed collagen blends were mixed with halloysite/antimicrobial nanohybrids at 10% and 20% (w/w) using glycerin or glycerin/polyethylene glycol-1500 as plasticizers. The films were characterized through the use of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and electron microscopy. The mechanical properties were evaluated macroscopically using tensile tests, and at a nanoscale through atomic force microscopy (AFM) and nanoindentation. Thermodynamic studies were conducted to assess their hydrophilic or hydrophobic character. Additionally, in vitro cytocompatibility tests were performed on human keratinocytes. Results from FTIR, TGA, AFM and electron microscopy confirmed the hybrid nature of the films. Both tensile tests and nanomechanical measurements postulated that the nanohybrids improved the films' toughness and adhesion and optimized the nanoindentation properties. All nanohybrid-loaded films were hydrophilic and non-cytotoxic, showcasing their potential for skin wound applications given their enhanced performance at the macro- and nanoscale.