Search Results (41)

Postoperative adhesions are a prevalent complication following abdominal surgeries, often leading to significant clinical challenges. This study introduces an innovative solution utilizing a polyethylene glycol (PEG)-based triblock copolymer to form an injectable, self-healing hydrogel aimed at preventing these adhesions. The hydrogel, formulated with temperature-responsive and self-healing properties through the incorporation of poly (N-isopropyl acrylamide) (PNIPAM) and anion–pi interactions, was synthesized using reversible addition–fragmentation chain transfer (RAFT) polymerization. The hydrogel’s physical properties, biocompatibility, hemostatic effect, and anti-adhesive capabilities were rigorously tested through in vitro and in vivo experiments involving rat models. It demonstrated excellent biocompatibility, effective tissue adhesion, and robust hemostatic properties. Most notably, it exhibited significant anti-adhesive effects in a rat abdominal wall–cecum model, reducing adhesion formation effectively compared to controls. The PEG-based injectable hydrogel presents a promising approach for postoperative adhesion prevention. Its ability to gel in situ triggered by body heat, coupled with its self-healing properties, provides a substantial advantage in clinical settings, indicating its potential utility as a novel anti-adhesion material. Full article

Traumatic non-compressible hemorrhage and subsequent wound management remain critical challenges in military and civilian settings to this day. Cryogels have emerged as promising hemostatic materials for non-compressible hemorrhage due to their blood-triggered shape recovery. In this study, a biodegradable and mechanically resilient cryogel (CF/PD) was produced via cryopolymerization, employing methacrylated recombinant collagen as a macromolecular crosslinker alongside poly (ethylene glycol) diacrylate (PEGDA) and dopamine methacrylate (DMA). With its interpenetrating macro-porous structure and high hydrophilicity, the CF/PD rapidly absorbs blood and returns to its original shape within 1.5 s. In a rat liver defect model, CF/PD outperformed commercially available gelatin sponges, reducing hemostasis time by 74.4% and blood loss by 76.5%. Moreover, CF/PD cryogels facilitate in situ tissue regeneration by virtue of the bioactivity and degradability of recombinant collagen. This work establishes a bioactive recombinant collagen-driven cryogel platform, offering a transformative solution for managing non-compressible hemorrhage while enabling tissue regeneration. Full article

Background/Objectives: Efficient wound treatment embraces the management of four overlapping phases, starting with hemostasis, an immediate physiological response aimed at stopping bleeding from damaged blood vessels caused by skin injury. This paper proposes an innovative, nature-based hemostatic biomaterial designed to assist natural self-healing regenerative mechanisms. Methods: Light, transparent, and skin-adhesive films based on κ-carrageenan, meadow polyfloral honey, and Calendula officinalis flower extract were fabricated via solution casting. Comprehensive characterization revealed the physicochemical, structural, swelling, and barrier properties and the influence of each bioactive compound utilized for film preparation. Results: The samples subcutaneously implanted in Wistar rats induced vascularization, deposition of collagen, and orientation of collagen fibers while being fully phagocytosed and gradually biodegraded. The rat tail-cut model demonstrated that the films significantly reduced blood loss (0.1875 ± 0.0732 g) compared to the control (0.7837 ± 0.3319 g), and hemostasis was achieved notably faster (355.75 ± 71.42 s) than in the control group (704.25 ± 85.29 s). The rat liver punch biopsy model confirmed reduced blood loss (2.8025 ± 1.5174 g) and shorter time to hemostasis (303.25 ± 77.90 s) compared to the control (3.1475 ± 1.5413 g, 383.00 ± 36.53 s). Conclusions: The results indicate the great potential of the fabricated films as hemostatic wound dressings. Full article

Water is the most environmentally friendly solvent; however, conventional solution spinning using water as a solvent is challenging due to its low evaporation rate. We developed a double-pronged solution blow spinning (DP-SBS) system. This spinning technique significantly enhances solvent evaporation, and the designed structure (double-pronged) avoids the common problem of needle clogging caused by heating. DP-SBS enables high-yield production of water-soluble polymer nanofibers, with a production rate of up to 5.94 g/h, which far exceeds what can be achieved with traditional electrospinning or solution blow spinning. This method is also highly efficient for producing non-water-soluble polymer nanofibers, achieving a production rate of up to 7.91 g/h, the highest reported value to date. Additionally, this approach can be used to produce not only common two-dimensional fiber membranes but also fiber sponges in a single step using the double-pronged airflow system. For the first time, chitosan nanofiber sponges were successfully produced and demonstrated to have excellent hemostatic properties in medical hemostasis. This method can also be extended to the production of other 3D nanomaterials, such as mullite nanofiber sponges, which exhibit outstanding thermal insulation performance at high temperatures. Full article

Adhesion between a red blood cell and substrates is essential to many biophysical processes and has significant implications for medical applications. This study derived a theoretical formula for the adhesive force between a red blood cell and a bulk substrate, incorporating the Hamaker constant to account for van der Waals interactions. The derivation is based on a biconcave shape of an RBC, described by the well-known Ouyang–Helfrich equation and its analytical solution developed by Ouyang. The theoretical predictions align with experimental observations and the empirical spherical model, revealing a $F\propto D^{-2.5}$ relationship for biconcave RBCs versus $F\propto D^{-2}$ for spheres. While the current study focuses on idealized geometries and static conditions, future work will extend these findings to more complex environmental conditions, such as dynamic flow and interactions with plasma proteins, thereby broadening the applicability of the model. This work bridges foundational research in cell membrane mechanics with practical applications in hemostatic materials, platelet adhesion, and biomaterials engineering. The findings provide insights for designing advanced biological sensors, surgical tools, and innovative medical materials with enhanced biocompatibility and performance. Full article

Background: An over-the-counter vasoconstrictive nasal solution with oxymetazoline (NS-OXY, 0.05%) has the potential to be used as a dental pulpal hemostatic medicament. A molecular engineering approach examined NS-OXY and its molecular constituent’s antimicrobial and blood biomass removal efficacy. Methods: An ex vivo cavity model was developed where standardized prepared teeth were exposed overnight to a model dentinal caries pathogen, S. mutans, and then exposed to sheep’s blood for 10 min, which simulated a pulpal exposure. Cavity preparations were rinsed with OXY (0.05%), benzalkonium chloride (BKC-0.025%), NS-OXY (with OXY-0.05% and BKC), ferric sulfate (20%;ViscoStat, FS), and distilled water (DI). For examining the bactericidal effect of NS-OXY, a disk diffusion antimicrobial assay was used where S. mutans was grown (20 h) on brain heart infusion (BHI) w/0.5% glucose agar plates and exposed to the treatment groups. Results: NS-OXY-treated samples had a lower residual bacterial or blood biomass than FS (p = 0.003). The diffusion test showed that NS-OXY, BKC, and FS had zones of inhibition greater than 10 mm, with NS-OXY having higher activity against S. mutans than FS (p = 0.0002), but lower than BKC (p = 0.0082). Conclusions: NS-OXY may be considered as a dental hemostatic agent after traumatic and carious pulpal exposure owing to NS-OXY’s antimicrobial and vasoconstrictive properties. Full article

Background/Objectives: Improvements in catheter connection design intended to increase safety have resulted in connections that are difficult to release manually. No medical device exists to safely disconnect catheter connections. Nurses and other users have developed workarounds including use of hemostats, tourniquets, and wrenches. These workarounds are not always successful for performing this task and can break catheters and catheter connections. This study aimed to evaluate a disconnection device to safely disconnect catheter connections. Methods: This is a mixed-methods study using a user-centered design approach with triangulation of quantitative and qualitative data mapped to Valdez’s sociotechnical framework. Nurses (N = 139) from units across two academic medical centers encompassing diverse patient populations engaged in usability testing and surveys. Data about users’ past catheter disconnection experiences and usability of the specialized disconnection device were collected and analyzed. Triangulation of quantitative data and qualitative themes was mapped using Valdez’s socio-technical framework to complement and strengthen the final design generated for nurses’ user requirements. Results: Ninety-five percent of nurses reported previous difficulty with disconnecting luer connections; 93% of those reporting difficulty improvised with readily available medical devices or products to better grip the connected parts. Over 85% of nurses reported positive experiences using the specialized disconnection device; others suggested design improvements for better performance. Conclusions: The nurses who tested the developed disconnection device reported high acceptability, accessibility, ease of use, and improved task performance. Moreover, as workarounds develop at points of practice where no systematic solution exists, aiming product development activities at these points help close gaps in achieving and maintaining patient safety. This study was not registered. Full article

Aim: This study aims to evaluate the management of oro-antral communications (OAC) and fistulas (OAF), focusing on treatment strategies based on defect size, epithelialization, and the presence of sinus infections, while exploring both traditional and emerging techniques. Materials and Methods: The systematic review was conducted following the PRISMA guidelines and registered on PROSPERO (CDR ID 623251). Using targeted keywords, articles in English published within the last 10 years were analyzed from databases such as PubMed, WoS and Scopus, selecting only clinical studies on human patients. After thorough screening, 20 publications were included in the qualitative analysis, among 734 initially identified. Results: Small OACs (<5 mm) were managed conservatively with hemostatic materials, while larger defects (>5 mm) required surgical closure, with the Bichat flap proving highly effective for large defects. Innovative treatments using autologous bone grafts and PRF showed promise in supporting tissue regeneration. In cases with sinusitis, the combination of FESS and intra-oral closure techniques resulted in high success rates for infection resolution and defect closure. Conclusions: Treatment outcomes for OAC and OAF are highly dependent on the size of the defect and the presence of sinusitis. Multidisciplinary collaboration, along with timely surgical intervention and adherence to medical therapies, is essential for successful management. Emerging techniques and minimally invasive procedures continue to improve patient outcomes, offering hope for more effective and sustainable solutions in complex cases. Full article

In the interests of using green and sustainable chemical innovations to create sustainable products with minimized (or no) chemical hazard potential, the polyester fabric in this work was activated and functionalized with chitosan and its durability was investigated. Chitosan is a natural biopolymer derived from chitin. As it has good biocompatibility, bio-absorption, anti-infectious, antibacterial and hemostatic properties and accelerates wound healing, it is increasingly being researched for the antimicrobial treatment of textiles. Due to the increased demands on the durability of antimicrobial properties during care, its binding to cellulose in cotton and cotton–polyester blends has been researched, but not to polyester alone. Therefore, the functionalization of polyester fabrics with chitosan by thermosol in the form of submicron particles and pad-dry-curing with homogenized gel was investigated in this work. The functionalization with chitosan was carried out on untreated polyester fabric and polyester fabric activated by alkali hydrolysis. In order to reduce the release of chemical substances during the entire life cycle of textile production, no binder was used. The effects were evaluated by electrokinetic analysis (zeta potential), and the mechanical, spectral, moisture management and antimicrobial properties were determined using standard methods. The functionalized polyester fabrics were submitted to 10 washing cycles in a solution of non-ionic surfactant for determination of its durability. It was shown that the functionalization of hydrolyzed polyester fabric with homogenized chitosan gel by pad-dry-curing results in excellent antimicrobial efficacy and moisture management properties while maintaining the mechanical properties of the fabric even after 10 washing cycles. Full article

The aim of this research was to synthesize and characterize alginate–calcium composites using a freeze-drying method, with a focus on their potential applications in biomedicine. This study specifically explored the biochemical properties of these composites, emphasizing their role in blood coagulation and their capacity to interact with DNA. Additionally, the research aimed to assess how the cross-linking process influences the structural and chemical characteristics of the composites. Detailed analyses, including microscopic examination, surface area assessment, and atomic absorption spectrometry, yielded significant results. The objective of this study was to examine the impact of calcium chloride concentration on the calcium content in alginate composites. Specifically, the study assessed how varying concentrations of the cross-linking solution (ranging from 0.5% to 2%) influence the calcium ion saturation within the composites. This investigation is essential for understanding the physicochemical properties of the materials, including calcium content, porosity, and specific surface area. The results are intended to identify the optimal cross-linking conditions that maximize calcium enrichment efficiency while preserving the material’s structural integrity. The study found that higher calcium chloride concentrations in alginate cross-linking improve the formation of a porous structure, enhanced by two-stage freeze-drying. Increased calcium levels led to a larger surface area and pore volume, and significantly higher calcium content. Furthermore, assays of activated partial thromboplastin time (aPTT) showed a reduction in clotting time for alginate composites containing calcium ions, indicating their potential as hemostatic agents. The aPTT test showed shorter clotting times with higher calcium ion concentrations, without enhanced activation of the extrinsic clotting pathway. The developed alginate material with calcium effectively supports hemostasis and reduces the risk of infection. The study also explored the capacity of these composites to interact with and modify the structure of plasmid DNA, underscoring their potential for future biomedical applications. Full article

Natural-based and synthetic tissue adhesives have attracted extensive attention in the last two decades for their ability to stabilize uncontrolled bleeding instances. However; these materials present several drawbacks during use that scientists have tried to minimize in order to optimize their usage. This study comprises the development of a novel wound dressing, combining the excellent properties of polylactic acid (PLA) non-woven textile, as substrate, obtained through electrospinning, and a cyanoacrylate-based (CA) tissue adhesive, for rapid hemostatic action. Thus, the fabrication of electrospun PLA membranes at three different PLA concentrations, the design and manufacturing of the support system and the production of surgical patches were carried out. SEM and FT-IR methods were employed for analyzing the morphology as well as the indicative markers for the shelf life evolution of the obtained patches. PLA fibers with well-defined structures and a mean diameter varying between 4.6 and 7.24 μm were obtained with the increase of the concentration of the PLA solutions. In vivo tests on a rat model as well as peeling tests for good patch adhesion on liver fragments harvested from the test animals, with a limit for the strength of the liver tissue of 1.5 N, were carried out. The devices exhibited excellent adhesion to the parenchymal tissue and a long enough shelf life to be used with success in surgical procedures, also facilitating prompt hemostatic action. Full article

Background/Objectives: This study evaluated the hemostatic performance and safety of ActiClot (ATC), a new flowable hemostatic agent, through in vivo tests. Methods: ATC was compared with the commercially available FLOSEAL^®. ATC consists of carboxymethyl starch, thrombin, and sorbitol powders in Syringe I, and a calcium chloride solution in Syringe II. In vivo evaluation used rat liver bleeding and porcine heart bleeding models. Safety was assessed using a rat subcutaneous implantation model. Results: ATC significantly reduced hemostasis time (70.00 ± 7.35 s) compared to gauze control (240.63 ± 32.31 s) in the rat liver model, showing a 70% reduction. There was no significant difference between ATC and FLOSEAL^® (58.75 ± 13.42 s). In the porcine heart model, both agents achieved 100% hemostasis within 3 min, with no significant difference in success rates within 2 min (ATC 87.5%, FLOSEAL^® 75%). The gauze control group failed in all tests. The rat subcutaneous implantation model showed no visual ATC observation after 48 h, indicating biocompatibility, with no inflammation observed. Conclusions: ATC demonstrated effective hemostatic performance similar to FLOSEAL^® in two in vivo models, with faster hemostasis in the rat liver model. It also showed excellent safety and biocompatibility, indicating its potential for surgical and emergency bleeding control. Full article

Background and Objectives: Gingival retraction is a critical pre-impression procedure in fixed prosthodontics, crucial for exposing tooth margins and ensuring accurate impressions for restorations like crowns and bridges. This study aimed to evaluate the absorptive capacity of different gingival retraction cords. Materials and Methods: Ninety samples each of Ultrapak (Ultradent, South Jordan, UT, USA) #00, braided cord, coreless thread, and monofilament thread (totaling 270 samples) were immersed in 0.9% NaCl, 10% aluminum chloride, and 12.7% ferrous sulfate solutions for 120, 300, and 1200 s. The liquid absorption capacity was measured using a gravimetric method, and the data were analyzed using an F-test, setting the significance threshold at p < 0.05. Results: The results revealed statistically significant differences in absorption, particularly for aluminum chloride and ferric sulfate (p < 0.001). Ultrapak demonstrated the highest absorption, followed by the coreless cotton thread, while the monofilament thread absorbed the least, especially at 1200 s. Conclusions: These findings indicate that Ultrapak’s superior absorption could enhance moisture control during procedures, highlighting the importance of selecting an appropriate retraction cord for optimal clinical outcomes. Further research is needed to confirm these findings in a clinical setting. Full article

A novel self-gelatinizing powder was designed to accelerate wound healing through enhanced hemostasis and tissue recovery. Significantly, this research addresses the critical need for innovative wound management solutions by presenting a novel approach. Carboxymethylcellulose calcium (CMC-Ca) was synthesized using an ion exchange method, and lysine (Lys) was integrated through physical mixing to augment the material’s functional characteristics. The prepared powder underwent comprehensive evaluation for its self-gelling capacity, gelation time, adhesion, swelling rate, coagulation efficiency, hemostatic effectiveness, and wound healing promotion. Results indicate that the self-gelatinizing powder exhibited remarkable water absorption capabilities, absorbing liquid up to 30 times its weight and achieving rapid coagulation within 3 min. The inclusion of Lys notably enhanced the powder’s gel-forming properties. The gelation time was determined to be within 4 s using a rotational rheometer, with the powder rapidly forming a stable gel on the skin surface. Furthermore, in a mouse skin injury model, near-complete skin recovery was observed within 14 days, underscoring the powder’s impressive self-healing attributes and promising application prospects in wound management. Full article

Uncontrollable bleeding is recognized as the leading cause of preventable death among trauma patients. Early transfusion of blood products, especially plasma replacing crystalloid and colloid solutions, has been shown to increase survival of severely injured patients. However, the requirements for cold storage and thawing processes prior to transfusion present significant logistical challenges in prehospital and remote areas, resulting in a considerable delay in receiving thawed or liquid plasma, even in hospitals. In contrast, freeze- or spray-dried plasma, which can be massively produced, stockpiled, and stored at room temperature, is easily carried and can be reconstituted for transfusion in minutes, provides a promising alternative. Drawn from history, this paper provides a review of different forms of dried plasma with a focus on in vitro characterization of hemostatic properties, to assess the effects of the drying process, storage conditions in dry form and after reconstitution, their distinct safety and/or efficacy profiles currently in different phases of development, and to discuss the current expectations of these products in the context of recent preclinical and clinical trials. Future research directions are presented as well. Full article