Sponge Dressings Research Articles

Hyaluronic acid-based ε-polylysine/polyurethane asymmetric sponge for enhanced wound healing

Asymmetric sponge dressings with a hydrophobic surface and a hydrophilic inner layer can prevent bacterial infiltration and ensure efficient absorption of wound exudate. In this work, ε-polylysine/aliphatic polyurethane sponge (EPU) was prepared by prepolymer foaming process, and oxidized hyaluronic acid (OHA) was cross-linked with ε-polylysine (EPL) in EPU through schiff-base reaction to obtain EHPU. Octaisobutyl polyhedral oligomeric silsesquioxane (Oi-POSS) was uniformly sprayed onto the surface of EHPU as the hydrophobic layer, resulting in asymmetric sponge dressings denoted as P-EHPU. These dressings demonstrate capabilities in resisting staining and bacterial invasion, with internal EPL effectively inhibiting bacterial proliferation on the wound surface. The introduction of OHA and EPL leads to a denser and more complete pore structure of the sponge, endowing it with good compression, tensile strength, and hemostatic performance. Wound healing studies indicate that P-EHPU effectively prevents external bacterial infiltration and promotes wound healing.

Amoxicillin-laded sodium alginate/cellulose nanocrystals/polyvinyl alcohol composite nanonetwork sponges with enhanced wound healing and antibacterial performance

Wound healing is a complex process and reuires a long repair process. Poor healing effect is normally a challenge for wound healing. Designing sponge dressings with drug-assisted therapy, good breathability, and multiple functional structures effectively promotes wound healing. In this work, a flexible amoxicillin-laded (AMX) sodium alginate (SA)/cellulose nanocrystals (CNCs)/ polyvinyl alcoho (PVA) (SA/CNCs/PVA-AMX, SCP-AMX) wound dressing was designed and built with an excellent porous structure, suitable porosity, and anti-bacterial properties for promoting wound tissue reparation. The porous structure of the wound dressing was fabricated by freeze-thawing cyclic and freeze-dried molding process. This wound dressing exhibited a 3D porous structure for soft-tissue-engineering application, including high porosity (84.2%), swelling ratio (1513%), tensile strength (1.79 MPA), and flexibility. With the inhibition zones of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) being 1.96 and4.58 cm, respectively, this wound dressing demonstrated good antibacterial activity against E. coli and S. aureus. More importantly, wound healing assay in vivo indicates that SCP-AMX could inhibit wound infection, promote collagen deposition, reduce inflammation, and accelerate granulation tissue and wound healing. Thus, the reported wounding dressings present excellent biocompatibility, high antibacterial activities, and excellent biosafety with great potential in wound healing applications.

3D Bilayered Hydrogel and Nanofiber Multifunctional Sponge Dressing: An Efficacious Healing Agent for Chronic Wound Healing.

Chronic wound management using biomaterial-based dressings has significantly impacted the standard and efficiency of wound healing. However, various available wound healing aids are ineffective in treating deep open injuries and chronic wounds such as diabetic wounds. Herein, we developed a 3D bilayered multifunctional sponge, which addresses the structural and functional issues faced by biomaterial dressings in treating deep and chronic wounds. The 3D bilayered sponge consists of a hydrogel base functionalized with wound healing peptide (Tylotoin)-carrying nanoparticles and topped with a nanofiber layer functionalized with an antimicrobial peptide (LLKKK18). The 3D bilayered sponge, with its highly porous, elastic, and enhanced fluid absorption ability, makes it a suitable wound treatment aid. The developed multifunctional 3D sponge shows antibacterial action and promotes a microenvironment similar to the extracellular matrix (ECM) in regulating dermal cell survival and migration. Study in a full-thickness skin defect diabetic mouse model has shown that the developed 3D bilayered sponge accelerated wound closure and promoted functional skin regeneration through reduced inflammation, faster granulation tissue formation, re-epithelialization, neovascularization, and skin appendage restoration, which make the developed 3D bilayered multifunctional sponge an efficient and advanced chronic wound management aid with potential for future clinical application.

COMPARATIVE STUDY BETWEEN THE EFFECTIVENESS OF AMNION-CollaGee [COLLAGEN–GELATIN–ELASTIN] AS A BIOLOGICAL PRODUCT WOUND DRESSING AND CONVENTIONAL DRESSING ON THE DONOR SITE OF THE SPLIT THICKNESS SKIN GRAFT IN ANIMALS MODEL (RATS)

Abstract Background The clinical application of amniotic membrane wound healing products is limited partially due to handling challenges. Amnion-CollaGee sponge dressing (ACS) provides better alternatives to traditional therapy in facilitating wound healing. Objective To optimize the effectiveness of ACS as a healing agent in donor-site split-thickness skin graft (STSG) based on in vitro outcomes. Followed by comparing wound healing rates, pain sensitivity, and risks of infection between investigator ACS dressing with currently conventional Duoderm dressing (DD) via in vivo analysis. Materials and methods Seven male Sprague-Dawley rats underwent STSG harvesting, with 1x1cm grafts taken from both the right and left sides of the animals' backs. The wounds on the right side (Group 1) were dressed with ACS, while the wounds on the left side (Group 2) were dressed with DD. The donor site wounds were assessed on the seventh, fourteenth, and twenty-first days of the experiment. Primary outcomes measured were rate of healing, pain sensitivity, potential risks of infection. Secondary outcomes were lesion vascularity, pigmentation and histopathological features. Results The size of the wounds treated with ACS was statistically smaller compared to that treated with DD. On day 21st, both types of dressings showed complete healing, thus, contributing to better aesthetic value. Additionally, superior pain suppression was witnessed at ACS-treated graft sites compared to DD. Histopathological reports displayed better post-traumatic wound site inflammatory control, less tissue scarring, and abundant collagen growth in the ACS wing compared to the DD counterpart. Conclusion The biological ACS dressing appeared to facilitate rapid wound healing rates, reduce the risk of exposed wound infections, and enhance pain suppression in rodent models. ACS based dressing agents are future interventional breakthroughs in graft donor site wound management.

Tannic Acid Incorporated Antibacterial Polyethylene Glycol Based Hydrogel Sponges for Management of Wound Infections.

Conventional wound dressings fail to provide features that can assist the healing process of chronic wounds. Multifunctional wound dressings address this issue by incorporating attributes including antibacterial and antioxidant activity, and the ability to enhance wound healing. Herein, polyethylene glycol (PEG)-based antibacterial hydrogel sponge dressings are prepared by a rapid and facile gas foaming method based on an acid chloride/alcohol reaction where tannic acid (TA) is included as a reactant to impart antibacterial efficacy as well as to enhance the mechanical properties of the samples. The results reveal that the TA-integrated sponges possess excellent antibacterial properties against both Escherichia coli and Staphylococcus aureus with approximately 6-8 log reduction in the microbial colony count after 6h, indicating their high potential for management of infection-prone wounds. Compared to the control sample, TA incorporation increases the elastic modulus by twofold. As the samples also exhibit biocompatibility, antioxidant activity, and wound healing capacity, the novel TA-incorporated hydrogels can be an alternative to traditional wound dressings for wounds with low-to-moderate exudate.

Preparation and characterization of a polyurethane-based sponge wound dressing with a superhydrophobic layer and an antimicrobial adherent hydrogel layer

Bacterial infection poses a significant impediment in wound healing, necessitating the development of dressings with intrinsic antimicrobial properties. In this study, a multilayered wound dressing (STPU@MTAI2/AM1) was reported, comprising a surface-superhydrophobic treated polyurethane (STPU) sponge scaffold coupled with an antimicrobial hydrogel. A superhydrophobic protective outer layer was established on the hydrophilic PU sponge through the application of fluorinated zinc oxide nanoparticles (F-ZnO NPs), thereby resistance to environmental contamination and bacterial invasion. The adhesive and antimicrobial inner layer was an attached hydrogel (MTAI2/AM1) synthesized through the copolymerization of N-[2-(methacryloyloxy)ethyl]-N, N, N-trimethylammonium iodide and acrylamide, exhibits potent adherence to dermal surfaces and broad-spectrum antimicrobial actions against resilient bacterial strains and biofilm formation. STPU@MTAI2/AM1 maintained breathability and flexibility, ensuring comfort and conformity to the wound site. Biocompatibility of the multilayered dressing was demonstrated through hemocompatibility and cytocompatibility studies. The multilayered wound dressing has demonstrated the ability to promote wound healing when addressing MRSA-infected wounds. The hydrogel layer demonstrates no secondary damage when peeled off compared to commercial polyurethane sponge dressing. The STPU@MTAI2/AM1-treated wounds were nearly completely healed by day 14, with an average wound area of 12.2 ± 4.3 %, significantly lower than other groups. Furthermore, the expression of CD31 was significantly higher in the STPU@MTAI2/AM1 group compared to other groups, promoting angiogenesis in the wound and thereby contributing to wound healing. Therefore, the prepared multilayered wound dressing presents a promising therapeutic candidate for the management of infected wounds. Statement of significanceHealing of chronic wounds requires avoidance of biofouling and bacterial infection. However developing a wound dressing which is both anti-biofouling and antimicrobial is a challenge. A multilayered wound dressing with multifunction was developed. Its outer layer was designed to be superhydrophobic and thus anti-biofouling, and its inner layer was broad-spectrum antimicrobial and could inhibit biofilm formation. The multilayered wound dressing with adhesive property could easily be removed from the wound surface preventing the cause of secondary damage. The multilayered wound dressing has demonstrated good abilities to promote MRSA-infected wound healing and presents a viable treatment for MRSA-infected wound.

Preparation and characterization of chitosan/polyvinyl alcohol antibacterial sponge materials

This study utilized the freeze-drying method to create a chitosan (CS) and polyvinyl alcohol (PVA) sponge. To enhance its antibacterial properties, curcumin and nano silver (Cur@Ag) were added for synergistic antibacterial. After adding curcumin and nano silver, the mechanical properties of the composite sponge dressing (CS-PVA-Cur@Ag) were improved. The porosity of the composite sponge dressing was closed to 80%, which was helpful for drug release, and it had good water absorption and water retention rate. The nano silver diameter was 50–80 nm, which was optimal for killing bacteria. Antibacterial tests used Escherichia coli and Staphylococcus aureus demonstrated that little nano silver was required to eliminate bacteria. Finally, in the rat full-thickness skin wound model, the composite sponge dressing can promote wound healing in a short time. In summary, CS-PVA-Cur@Ag wound dressing could protect from bacterial infection and accelerate wound healing. Thus, it had high potential application value for wound dressing.

A novel approach to wound healing: Green synthetic nano-zinc oxide embedded with sodium alginate and polyvinyl alcohol hydrogels for dressings

Wound healing constitutes a formidable challenge within the healthcare system, attributable to infection risks and protracted recovery periods. The pressing need for innovative wound healing methods has spurred the urgency to develop novel approaches. This study sought to advance wound healing by introducing a novel approach employing a composite sponge dressing. The composite sponge dressing, derived from LFL-ZnO (synthesized through the green methodology utilizing Lactobacillus plantarum ZDY2013 fermentation liquid), polyvinyl alcohol (PVA), and sodium alginate (SA) via a freeze–thaw cycle and freeze-drying molding process, demonstrated notable properties. The findings elucidate the commendable swelling, moisturizing, and mechanical attributes of the SA/LFL-ZnO/PVA composite sponge dressing, characterized by a porous structure. Remarkably, the dressing incorporating LFL-ZnO exhibited substantial inhibition against both methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (S. aureus). Hemolysis and cytotoxicity tests corroborated the excellent biocompatibility of the sponge dressing. In vivo evaluation of the therapeutic efficacy of the 1 mg/mL LFL-ZnO composite dressing on scald wounds and S. aureus-infected wounds revealed its capacity to accelerate wound healing and exert pronounced antibacterial effects. Consequently, the composite sponge dressings synthesized in this study hold significant potential for application in wound treatment.

Retracted: Effect and Repair Mechanism of Nano Ag Sponge Dressing Combined with Gelatin-Bletilla Striata Gum/Salvia Miltiorrhiza on Refractory Orthopedic Wounds.

[This retracts the article DOI: 10.1155/2021/8872235.].

Muscle-inspired lamellar chitosan sponge with photothermal antibacterial and antioxidant properties for hemostasis and accelerated bacteria infected wound healing

Wound dressings with excellent hemostasis, antibacterial, and antioxidant properties are essential for hemorrhagic infected wounds. Herein, inspired by the highly anisotropic and ordered fibrous structure of muscle tissue, we prepared chitosan/polydopamine biomimetic layered sponge dressings loaded with cerium dioxide (CeO2) nanoparticles by a directional freezing method. This composite sponge has an ordered laminate structure, good mechanical properties, excellent moisture absorption, and swelling properties. Thanks to the introduction of PDA, the composite sponge has outstanding photothermal properties and effectively kills bacteria under 808 nm near-infrared (NIR) light. In addition, the CeO2 loaded in the composite sponge also has an excellent ROS scavenging capacity, which protects cells from oxidative stress damage. The rat tail amputation and liver hemostasis experiment proved that this layered sponge had good hemostasis performance. Furthermore, the full-thickness skin defect model infected with S. aureus demonstrated that the composite sponge accelerated wound closure, promoted collagen deposition, down-regulated pro-inflammatory factors (TNF-α), and up-regulated anti-inflammatory factors (IL-10) expression, ultimately promoting wound healing. All the results suggested that this bionic sponge with a directional layered structure has a preferable therapeutic effect on the healing of infected wounds and is expected to be a more advantageous wound dressing.

A modified chain-based sponge dressing controls junctional hemorrhage in the tactical combat casualty care simulation of pigs

BackgroundHemorrhage has always been the focus of battlefield and pre-hospitalization treatment. With the increasing fatality rates associated with junctional bleeding, treatment of bleeding at junctional sites has gradually gained attention in battlefield trauma emergency care. We designed a modified chain-based sponge dressing with a medical polyvinyl alcohol sponge that can be used to treat junctional hemorrhage and tested its hemostatic efficacy and biocompatibility.MethodsTwenty adult Bama miniature pigs were randomly divided into the modified chain-based sponge dressing (MCSD) and standard gauze (SG) groups. The right femoral artery of the pigs was shot at after anesthesia. The Bama miniature pigs were moved to the safety zone immediately to assess the condition according to the MARCH strategy, which evaluates massive hemorrhaging, airway obstruction, respiratory status, circulatory status, head injury & hypothermia. Hemoglobin and coagulation status were checked during the experiment.Among the pigs in which the inguinal hemorrhagic model based on bullet penetrating wounds was successfully established, those in the MCSD group received a disinfected MCSD for hemostasis, while those in the SG group received standard gauze in an imbricate manner to pack the bullet exit and entrance wounds to stop bleeding until the wound was filled, followed by compression for 3 min at sufficient pressure. CT scanning, transmission electron microscopy, and HE staining were conducted after experiment.ResultsThe MCSD group showed lower hemostasis time and blood loss than the gauze group. The MCSD group also showed a higher success rate of treatment,more stable vital signs and hemoglobin level. The CT scanning results showed tighter packing without large gaps in the MCSD group. The histopathological assessments and the transmission electron microscopy and HE staining findings indicated good biocompatibility of the polyvinyl alcohol sponge.ConclusionThe MCSD met the battlefield’s requirements of speedy hemostasis and biosafety for junctional hemorrhage in Bama miniature pigs. Moreover, in comparison with the conventional approach for hemostasis, it showed more stable performance for deep wound hemostasis. These findings provide the theoretical and experimental basis for the application of MCSD in the treatment of hemorrhage in the battlefield in the future.

Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing

ObjectiveThis study tests the efficacy of Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMC), baicalin (BA) and silver titanate (ST) in a wound dressings to fight infection, promote healing and provide superior biocompatibility. MethodsThe antibacterial activity of BA and ST was evaluated in vitro using the inhibition zone method. BA/ST/BSP/CMC porous sponge dressings were prepared and characterized. The biocompatibility of BA/ST/BSP/CMC was assessed using the cell counting kit-8 assay. The therapeutic effect of BA/ST/BSP/CMC was further investigated using the dorsal skin burn model in Sprague-Dawley rats. ResultsThe wound dressing had good antibacterial activity against Escherichia coli and Staphylococcus aureus through BA and ST, while the combination of BSP and CMC played an important role in promoting wound healing. The BA/ST/BSP/CMC porous sponge dressings were prepared using a freeze-drying method with the concentrations of BA and ST at 20 and 0.83 mg/mL, respectively, and the optimal ratio of 5% BSP to 4% CMC was 1:3. The average porosity, water absorption and air permeability of BA/ST/BSP/CMC porous sponge dressings were measured to be 90.43%, 746.1% and 66.60%, respectively. After treatment for 3 and 7 days, the healing rates of the BA/ST/BSP/CMC group and BA/BSP/CMC group were significantly higher than those of the normal saline (NS) group and silver sulfadiazine (SSD) group (P < 0.05). Interleukin-1β expression in the BA/ST/BSP/CMC group at 1 and 3 days was significantly lower than that in the other three groups (P < 0.05). After being treated for 3 days, vascular endothelial growth factor expression in the BA/BSP/CMC group and BA/ST/BSP/CMC group was significantly higher than that in the NS group and SSD group (P < 0.05). Inspection of histological sections showed that the BA/ST/BSP/CMC group and BA/BSP/CMC group began to develop scabbing and peeling of damaged skin after 3 days of treatment, indicating accelerated healing relative to the NS group and SSD group. ConclusionThe optimized concentration of BA/ST/BSP/CMC dressing was as follows: 6 mg BSP, 14.4 mg CMC, 0.5 mg ST and 12 mg BA. The BA/ST/BSP/CMC dressing, containing antibacterial constituents, was non-cytotoxic and effective in accelerating the healing of burn wounds, making it a promising candidate for wound healing.Please cite this article as: Gong YR, Zhang C, Xiang X, Wang ZB, Wang YQ, Su YH, Zhang HQ. Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing. J Integr Med. 2023; 21(5): 487–495.

Chitosan/poly (ethylene oxide) nanofiber sponge with dual-responsive drug release and excellent antibacterial property

An ideal wound dressing can absorb wound exudate in time, and has the advantages of moisture permeability, oxygen permeability, rapid hemostatic performance, antibacterial and low-toxic, which are the key to wound healing. However, traditional wound dressings exist structural and functional defects, especially in controlling bleeding and active wound protection. Herein, a novel three-dimensional chitosan/ poly (ethylene oxide) sponge dressing (3D CS/PEO sponge-ZPC) consists of CS/PEO nanofiber sponge (carrier unit), Zn metal-organic framework grown in-situ (Zn-MOF, drug loading unit and antibacterial unit), curcumin (CUR, antibacterial unit), and poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (P(NIPAM-co-MAA), ‘gatekeepers’ unit) to promote the wound healing by absorb exudate in time, accelerate hemostasis and inhibit bacteria growth. Due to the unique structure of the as-prepared 3D CS/PEO sponge-ZPC was endowed with smart stimuli-responsive drug release mode, rapid hemostatic performance and strong antibacterial property. The result of CUR release showed smart “ON-OFF” drug release mode. Antibacterial results verified strong antibacterial property up to 99.9 %. Hemolysis test showed that hemolysis ratio of 3D CS/PEO sponge-ZPC met the acceptable standard. The rapid hemostatic property was demonstrated by hemostatic test. High wound healing effect was confirmed in vivo. These results provide an important research basis for the design of new smart dressing.

Chitosan Sponge/Cu-WO3-x Composite for Photodynamic Therapy of Wound Infection.

One of the potential treatments for bacterial wound infections is photodynamic therapy. WO3-x semiconductor materials can generate reactive oxygen species when exposed to light, which can inactivate bacteria. In this work, we improved their photocatalytic performance by doping WO3-x with Cu. The wound dressing was prepared by loading Cu-WO3-x into a highly biocompatible chitosan sponge. The composite sponge dressing showed significant inactivation of Escherichia coli and Staphylococcus aureus, and in vitro toxicity assays on L929 cells demonstrated the biosafety of the dressing. Through in vivo wound healing trials, composite sponge dressings have been shown to accelerate wound healing, and this composite chitosan sponge can be possibly used for photodynamic therapy of bacterial wound infections.

Comparative Effectiveness of 2 Chlorhexidine Gluconate-Containing Dressings in Reducing Central Line-Associated Bloodstream Infections, Hospital Stay, and Costs.

Chlorhexidine gluconate (CHG)-containing dressings are recommended to prevent central line associated bloodstream infections (CLABSIs) and other catheter-related infections. This study compared the effect of 2 CHG dressings on CLABSI, cost of care, and contact dermatitis. A retrospective analysis was conducted using the Premier Healthcare Database of hospitalized patients (n = 53 149) with central venous catheters (CVCs) and receiving either a transparent CHG gel dressing (n = 14 488) or an opaque CHG sponge dressing (n = 38 661) between January 2019 and September 2020. Two cohorts (n = 14 488 each), CHG-Gel and CHG-Sponge, were matched 1:1 using a propensity score method on 33 patient and facility characteristics. CLABSI and contact dermatitis rates, hospital length of stay (LOS), and hospitalization costs were compared using mixed-effect multiple regression. This approach effectively controlled for random clustering effects across hospitals and patients' Diagnosis-Related Group (DRG) classifications. CHG gel dressings were associated with a 41% decrease in CLABSI rates (P = .0008) compared to CHG sponge dressings (0.35%vs 0.60%). A 0.4-day shorter LOS (9.53vs 9.90 days, P = .0001) and a cost saving of $3576 per hospital stay ($40 197 vs $43 774, P = .0179) was observed with CHG gel dressing use. There was no statistically significant difference in contact dermatitis rates (P = .7854) between the CHG-Gel and CHG-Sponge cohorts. The findings of this study suggest that the use of CHG gel dressings may be more effective in reducing the risk of CLABSIs and associated clinical costs compared to CHG sponge dressings in hospitalized patients. Moreover, there appears to be no significant discrepancy in contact dermatitis rates between CHG gel and CHG sponge dressings. Healthcare providers may consider using CHG gel dressings as a standard practice for patients with CVCs to reduce the risk of infections and improve patient outcomes.

Biomimetic multifunctional hybrid sponge via enzymatic cross-linking to accelerate infected burn wound healing

Preparing sponge dressings with stable wet adhesion remains difficult in wound repair, especially in burn wounds with bleeding and large amounts of exudate. In this work, a multifunctional hybrid sponge dressing (DHGT+PHMB+TiO2NPs) with good wet adhesion was developed by combining biomimetic and enzymatic cross-linking reactions. The sponge dressing matrix (DHGT) was prepared by tyrosinase-catalyzed cross-linking of dopamine-modified hyaluronic acid (DOPA-HA) and gelatin. The multifunctional hybrid sponge dressing was obtained by loading polyhexamethylene biguanide (PHMB) and titanium dioxide nanoparticles (TiO2NPs) onto the DHGT matrix. The newly developed sponge dressing exhibited high mechanical properties, good wet adhesion, antibacterial activity, reactive oxygen species (ROS) scavenging, biocompatibility, and excellent hemostasis ability. In vivo studies showed that the multifunctional hybrid sponge dressing could significantly accelerate the healing of infected full-thickness burn wounds by inhibiting bacterial growth, accelerating skin tissue reepithelialization, collagen deposition, and angiogenesis, as well as regulating the expression of inflammatory factors and cytokines.

An antibacterial hemostatic AuNPs@corn stalk/chitin composite sponge with shape recovery for promoting wound healing

The development of shape-memory sponge dressings with functions, such as hemostasis, antibacterial activity, and wound healing, is of great significance in clinical applications. Herein, a novel AuNPs@corn stalk/chitin composite sponge (CCAu) was fabricated by crosslinking the chitin matrix with corn stalk-embedded gold nanoparticles (AuNPs). The addition of AuNPs@corn stalk gave the porous chitin sponge shape-recovery ability with improved softness, porosity, and water absorption. Correspondingly, the composite sponge showed better hemostatic effects than commercial PVF sponges. The photothermal effect of AuNPs endowed the composite sponge with excellent antibacterial activity. In addition, the wound treated with composite sponge containing antioxidant AuNPs exhibited a significantly faster wound healing rate (reaching 41.6 % on day 3) than the CH (33.2 %) and control (12.6 %) group through promoting cell migration, angiogenesis and collagen deposition. Therefore, the multifunctional composite sponge with great biocompatibility in this work provides a potential strategy for wound healing.

Comparison of the wound-healing efficacy of gelatin sponge dressings and that of artificial dermis using atelocollagen in a rat cranial periosteal defect model.

In oral surgery, tissue loss may occur in some cases, resulting in bone exposure and subsequent wound infection and possible scar formation during secondary healing. In this study, Terudermis® Artificial Dermis (AD-T), a dermal defect graft made from processed bovine dermis collagen and gelatin sponge (GS) were used as dressings on 100-mm2 wounds with exposed bone on the heads of rats. For the control group, the wound was left exposed. The wound-healing efficacy of the treatment was compared macroscopically and histologically among the three groups at 1, 2, and 4 weeks after surgery. Complete wound healing was achieved faster in the AD-T group than in the GS group, and osteoblasts appeared on the bone surface, indicating accelerated bone remodeling. Furthermore, in the AD-T group, there was an increased production of newly formed blood vessels, fibroblasts and osteoblasts positive for anti-cortactin antibodies, which are believed to contribute to wound healing. Our findings suggest that AD-T is better than GS as a wound dressing material.

Management of venous flap insufficiency: the role of low molecular weight heparin in salvage

Flap loss resulting from venous insufficiency is a difficult issue, both with pedicled or free flaps. We examined the efficiency of low molecular weight heparin administration in various forms and dressing methods in venous insufficiency. Forty-five Sprague Dawley rats were included and inferior epigastric artery perforated island flaps were obtained from the abdominal skin of the animals. Nine animals were randomly allocated to each of five experimental groups: sham-control (Group 1), venous occlusion only (Group 2), occlusion with systemic enoxaparin (Group 3), occlusion with systemic enoxaparin + local enoxaparin infusion to the punctiform incisions (Group 4), and occlusion with systemic enoxaparin + local enoxaparin infusion to the punctiform incisions and enoxaparin-impregnated sponge dressing (Group 5). Group 5 had higher flap survival rates than the other groups. Groups 3 and 4 had numerically better vitality than the control group, but the difference was not significant. Low molecular weight heparin administration, with or without punctiform incisions, is not efficient in rescuing flaps with venous insufficiency. Specialised dressing methods are necessary to maintain bleeding.

Preparation and characterization of antibacterial polyvinyl alcohol/chitosan sponge and potential applied for wound dressing

In this work, polyvinyl alcohol (PVA) with antimicrobial properties (QPVD), which were modified by 2-(Dimethylamino)ethyl methacrylate (DMAEMA) and 1-bromobutane. QPVD/chitosan (CS) composite sponge dressing (QPVDC) were prepared using freeze-drying process and cross-linked with glutaraldehyde vapor. Interestingly, compared with CS wound dressing, water absorption and flexibility of QPVDC wound dressing could be significantly improved with QPVD introduced. Among them, the water absorption of QPVDC sponge was up to 2300% and the elongation at break increased by 40–113%. In addition, QPVDC sponges with more quaternary ammonium could improve higher antibacterial activity, and the highest antibacterial activity of QPVDC sponges was close to 100% against E. coli and S. aureus. The results of hemolysis and cytotoxicity in vitro indicated that QPVDC wound dressing had excellent hemocompatibility and cytocompatibility. In summary, QPVDC wound dressing could protect from bacterial infection and accelerate wound healing. Thus, QPVDC had high potential application value for wound dressing.