Wound Exudate Research Articles

Smartphone-enabled 3D origami-fluidic paper-based electrochemical detection of myeloperoxidase activity for assessing wound infection

Early diagnosis of wound infections that aid in the assessment of the stage of wound infection is gaining interest for development of a new biomarker. In present research, a simple and portable 3D origami-fluidic paper-based electrochemical sensor is proposed for the detection of myeloperoxidase (MPO) activity in wound exudate samples. The flow can be manipulated by an origami pattern of the paper allowing the electrochemical reaction to occur on the electrode surface. Glucose oxidase (GOx) was used for producing hydrogen peroxide (H2O2) and MPO antibodies were immobilized to capture the MPO to enhance the specificity. Prussian blue/MXene composite modified on the electrode act as a nanozyme for catalyzing H2O2. Then, data is wirelessly transferred to a smartphone using near-field communication (NFC) technology. Under the optimal conditions, our proposed device can detect MPO activity in ranges 0.5–5 U/ml (R2 =0.9697), demonstrating a strong correlation with a colorimetric MPO activity kit when tested with real wound fluid samples (n = 6, R2 = 0.9198). Notably, our method can differentiate between non-infected and infected wounds (p-value < 0.05) by analyzing MPO activity extracted from used wound-dressing gauzes (n = 10). Therefore, our device offers a rapid portable device for MPO activity that is promising for resource-limited settings.

Use of a portable negative pressure wound therapy device on a hard-to-heal wound with exposed bone: a case study.

This case study examines the effectiveness of using negative pressure wound therapy (NPWT) in the management of a hard-to-heal (chronic) wound with exposed ankle bone to reduce associated wound exudate and promote production of granulation tissue. A 60-year-old male patient who was able to attend wound follow-up diligently twice weekly for eight weeks, and weekly thereafter, was selected from a private hospital to take part. During each dressing change, the wound was cleansed with superoxidised cleansing solution, and minimal sharp debridement was performed. In the authors' opinion, the NPWT device used in this study is light and convenient for use in the community or home care setting. The NPWT wound dressing was connected to the NPWT machine via a connecting tube and the device then switched on using the default setting of a negative pressure of 125mmHg. Following the application of the NPWT device, the exposed ankle bone was successfully covered with healthy granulation tissue and healed within 20 weeks with minimal exudate formation in the wound. In the authors' opinion, NPWT is able to promote progress to wound healing; to minimise unnecessary dressing changes and, based on feedback from the patient, is comfortable to wear and when in use.

Guard against internal and external: An antibacterial, anti-inflammation and healing-promoting spray gel based on lyotropic liquid crystals for the treatment of diabetic wound

The diabetic wound is a prevalent and serious complication of diabetes, which easily deteriorates due to susceptibility to infection and difficulty in healing, causing a high risk of amputation and economic burden to patients. Bacterial infection, persistent excessive inflammation, and cellular and angiogenesis disorders are the main reasons for the difficulty of diabetic wound healing. In this study, glycerol monooleate (GMO) was used to prepare lyotropic liquid crystal hydrogel (LLC) containing the natural antimicrobial peptide LL37 and carbenoxolone (CBX) to achieve antibacterial, anti-inflammation, and healing promotion for the treatment of diabetic wounds. The shear-thinning properties of the LLC precursor solution allowed it to be administered in the form of a spray, which perfectly fitted the shape of the wound and transformed into a gel after absorbing wound exudate to act as a wound protective barrier. The faster release of LL37 realized rapid sterilization of wounds, controlled the source of inflammation, and accelerated wound healing. The inflammatory signaling pathway was blocked by the subsequently released CBX, and the spread of the inflammatory response was inhibited and then further weakened. In addition, CBX down-regulated connexin (Cx43) to assist LL37 to promote cell migration and proliferation better. Combined with the pro-angiogenic effect of LL37, the healing of diabetic wounds was significantly accelerated. All these advantages made LL37-CBX-LLC a promising approach for the treatment of chronic diabetic wounds.

Carboxymethyl chitosan-gelatin-mesoporous silica nanoparticles containing Myrtus communis L. extract as a novel transparent film wound dressing

Wound healing and health care requirements have attracted more attention, and the need to develop new drug-containing dressings to accelerate wound healing is required. Carboxymethyl chitosan (CMCS)/gelatin-based films with mesoporous silica nanoparticles (MSNs) containing the Myrtus communis L. (Myrtle) aqueous extract were designed to answer this demand. Myrtle aqueous extract included total phenolic content and good free radical scavenging ability in vitro assay. The infrared spectroscopy characterized the functional groups of myrtle extract and biocomposite films. It was found that mesoporous silica nanoparticles increased the tensile strength of the flexible dressings, which is essential in therapeutic uses. MSNs influenced swelling ratio, oxygen, and water vapor permeability that indicates the CMCS/Gelatin/Myrtle/5 % MSNs wound dressing can absorb wound exudates and preserve skin moisture. Also, these biocompatible nanoparticles reduced the cytotoxicity of fibroblast cells due to the decelerated drug release. Correspondingly, silica nanoparticles affected the extract release rate and could accumulate and release the extract prolonged in CMCS/Gelatin/Myrtle/5 % MSNs models. Finally, histological analysis showed collagen growth and fibroblast migration in wounds treated with CMCS/Gelatin/Myrtle/5 % MSNs, causing proper wound contraction and accelerating wound healing in mice models. The results suggest that CMCS/Gelatin/Myrtle/5 % MSNs films have a beneficial application as wound dressings.

Accelerating Full-Thickness Wound Healing with Bacterial Cellulose-Based Multilayer Composites

Materials that speed up wound healing can be of great benefit to patients and healthcare providers. One-layer dressings, however, have unsatisfactory healing efficacy since it is impossible to use materials with different properties simultaneously, and drug delivery is limited by the depth of penetration. The present study utilized a multilayer wound dressing composed of bacterial cellulose (BC) hydrogel, gelatin/alginate (Gel/Alg) hydrogel, and polycaprolactone (PCL) nanofibers loaded with ciprofloxacin (CIP) to promote the healing process in vivo. The designed dressings showed significant water absorption and sufficient water vapor transmission rate (WVTR) after one week, confirming their ability to absorb wound exudate. Within the first four hours, significant amounts of CIP were released from the drug-containing dressing. Then, between hours 4 and 24, the rate decreased and plateaued on day 9. Both positive and negative bacterial strains were inhibited by the gradual release of CIP, while fibroblasts retained their normal morphology and metabolic activity. Lastly, in vivo tests demonstrated that CIP-loaded multilayer dressings could significantly speed up full-thickness wound healing during 14 days, by reducing inflammation, stimulating re-epithelialization, and enhancing skin regeneration. Our findings indicate that multilayering BC hydrogels with drug-loaded nanofibers provide a promising way to promote wound healing by utilizing all the distinctive properties of these layers.

MICROBIOLOGICAL CHARACTERISTICS OF THE LAPAROTOMIC WOUND, WHEN COMPLETE EVENTRATION BEGINNING, IN THE ONCOLOGICAL PROCESS

The aim of the study –to study the peculiarities of the qualitative and quantitative compositionof the microflora of the wound exudate of the laparotomy wound, complicated by the eventration,depending on its degree, in patients with malignant neoplasms of the abdominal cavity.Materials and methods.28 patients with malignant neoplasms of abdominal organs who hadpostoperative eventration were studied. The main group consisted of 12 patients who hada complete eventration (grade II-IV). The comparison group was formed by 16 patients whohad subcutaneous eventration (I degree). The collection of biological material was carriedout during the 8th day of the early postoperative period, by bacteriological examinationof the wound exudate, during dressings. Species composition of microorganisms, theirpopulation level, the coefficient of constancy, the frequency of species detection, thecoefficient of significance, the coefficient of quantitative dominance was studied.Results. When eventration II-IV degrees occurs, against a background of the oncologicalprocess, a probable predominance of the number of strains of E. coli, S. aureus and m/o ofthe genus Proteus is noted, and the number of strains of E. coli is likely to prevail during allperiods of observation. During the development of II-IV degrees of eventration, due to theoncological process, in the exudate of the laparotomy wound, there is a probable predominanceof the population level of E. coli, S. aureus and m/o of the genus Proteus. The dominantmicroorganism, according to the determined coefficient of quantitative dominance, at alldegrees of eventration, throughout the entire period of the study, is E. coli, and Enterococcusfaecalis is in the second place. At the same time, at all degrees of eventration, high numbers ofthe coefficient of quantitative dominance in S. aureus are noted on the 6-8th day of the study. &#x0D; Conclusions. With the development of postoperative eventration of II-IV degrees, inpatients with malignant neoplasms of the abdominal cavity, a probable increase in thenumber of strains sown and the population level of microorganisms in the laparotomywound exudate with E. coli, S. aureus and microorganisms of the genus Proteus is noted.In patients with malignant neoplasms of the abdominal cavity, with the occurrence ofII-IV degrees of postoperative eventuration, the dominant microorganisms of the woundexudate are E. coli and Enterococcus faecalis and microorganisms of the genus Proteus.

A new strategy to treat Pseudomonas aeruginosa infected burn wounds: Antimicrobial cocktails as potent topical therapy

Burn insults are traumatic as they inflict intense damage on different layers of skin and other organic body tissues, causing alterations in host's immune system, thereby, impairing the wound healing process. Weakened immune system and damaged natural cutaneous barrier opens a doorway for microorganisms to inhabit and infect burn wounds, lengthening hospital stays, and escalating the mortality rates. The most prominent burn wound infection-causing bacteria is Pseudomonas aeruginosa, which is accountable for higher mortality rates and is most ubiquitous among all the other burn wound pathogens because of its inclination to flourish in the moist environment causing invasive infections and selective advantage to grow within burn wound exudates. Due to the alarming rise in multi-drug resistance, the conventional therapy to treat burn insults and subsequent infections involving surgical removal of devitalized tissue, flushing wound site with normal saline, and employment of antibiotics topically is rendered ineffective suppressing physicians in their treatment choices and resulting in adverse outcomes observed in burn units. Despite advancements in the burn care field, rising drug resistance and its related consequences is necessitating vigorous research to devise an antimicrobial therapy targeting three broad areas collectively, for instance, P. aeruginosa infection management, immunomodulation, and wound healing. Hence, we propose formulating an antimicrobial cocktail exhibiting anti-infective, immunomodulatory, and wound healing properties having potential to improve survival rates among the P. aeruginosa infected burn populations, owning to its simple and easy application in resource-limited settings.

A sandwich-like silk fibroin/polysaccharide composite dressing with continual biofluid draining for wound exudate management

Optimal wound healing requires a wet microenvironment without over-hydration. Inspired by capillarity and transpiration, we have developed a sandwich-like fibers/sponge dressing with continuous exudate drainage to maintain appropriate wound moisture. This dressing is prepared by integrating a three-layer structure using the freeze-drying method. Layer I, as the side that contacts with the skin directly, consists of a hydrophobic silk fibroin membrane; Layer II, providing the pumping action, is made of superabsorbent chitosan-konjac glucomannan sponge; Layer III, accelerating evaporation sixfold compared to natural evaporation, is constructed with a graphene oxide soaked hydrophilic cellulose acetate membrane. Animal experiments showed that the composite dressing had superior wound-healing characteristics, with wounds decreasing to 24.8% of their original size compared to 28.5% for the commercial dressing and 43.2% for the control. The enhanced wound healing can be ascribed to the hierarchical porous structure serves as the fluid-driving factor in this effort; the hydrophilicity of a membrane composed of silk fibroin nanofibers is adjustable to regulate fluid-transporting capacity; and the photothermal effect of graphene oxide guarantees exudates that have migrated to the top layer to evaporate continuously. These findings indicate the unidirectional wicking dressing has the potential to become the next generation of clinical dressings.

Optimization of the Green Extraction of Red Araçá (Psidium catteyanum Sabine) and Application in Alginate Membranes for Use as Dressings.

In this research, the aim was to introduce innovation to the pharmaceutical field through the exploration of an underutilized plant matrix, the red araçá, along with the utilization of sodium alginate for the development of membranes designed for active topical dressings. Within this context, optimal extraction conditions were investigated using the central composite rotational statistical design (CCRD) to obtain a red araçá epicarp extract (RAEE) rich in bioactive compounds utilizing the maceration technique. The extract acquired under the optimized conditions (temperature of 66 °C and a hydroalcoholic solvent concentration of 32%) was incorporated into a sodium alginate matrix for the production of active membranes using a casting method. Characterization of the membranes revealed that the addition of the extract did not significantly alter its morphology. Furthermore, satisfactory results were observed regarding mechanical and barrier properties, as well as the controlled release of phenolic compounds in an environment simulating wound exudate. Based on these findings, the material produced from renewable matrices demonstrates the promising potential for application as a topical dressing within the pharmaceutical industry.

Hydro Electroactive Janus Micro/Nano Fiber Dressing with Exudate Management Ability for Wound Healing

Exudate management and bioelectric signals are critical to promoting wound healing. In this study, the thermoplastic polyurethane (TPU) nanofiber is directly electrospun on the cotton microfibers (Cotton) to prepare a Janus dressing (TPU/Cotton), which can unidirectionally drain the excess exudate. Then, Ag/Zn dot electrodes are deposited on the TPU layer, which can produce an electric field penetrating the wound when activated by wound exudate. The hydro‐activated Ag/Zn's electrical stimulation (ES) can promote the migration of fibroblast cells and shows excellent antibacterial activity against E. coli and S. aureus. Furthermore, in vivo experiments show that the exudate management coupled with ES accelerated wound healing at multiple stages by promoting re‐epithelization, collagen deposition, and vascularization. Moreover, the Ag/Zn@TPU/Cotton dressing shows excellent biocompatibility in the vitro cytotoxicity experiments. These findings may shed some light on developing the next generation of wound dressings with self‐activated electrical stimulation and exudate management.

Study of Effectiveness of Curcumin-Chitosan-Aloe Vera Healing Agent with Mupirocin for the Treatment of Aseptic Wounds in Dogs

Background: The study was conducted to evaluate the wound healing potential of nano-based curcumin-chitosan-aloe vera, an indigenously prepared healing agent, for treatment of aseptic surgical wounds in clinical canine cases presented to the Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Odisha University of Agriculture and Technology, Bhubaneswar. Methods: The wounds were assigned into two therapeutic regimens, application of nano-based healing agent and mupirocin to the test and control group respectively as topical therapy along with parenteral antibiotics as per standard operative procedure (SOP). Results were statistically analyzed, using analysis of variance (ANOVA), paired t-test (parametric) and kruskal-wallis one way ANOVA test (non parametric). Result: Chitosan-curcumin-aloevera based healing agent resulted in early reduction of wound exudates and cast formation than control group. Time of appearance and filling of wound bed by granulation tissue was significantly better in test group than control group. Early appearance of epithelium and the percentage of wounds with epithelium were also higher in test group than control group. Histological and histo-chemical findings on day 14 after surgery suggested less inflammatory reaction, more fibroblasts and neo-vascularisation, wider and compact granulation tissue in test group than control group. The values of clinical, haematological and biochemical parameters remained within the normal physiological limits without any significant difference. The average duration taken for complete healing in test and control groups was 9 and 14 days respectively without any sign of infection during the treatment period.

Efficacy of Autologous Platelet-Rich Gel Combined with Negative Pressure Drainage in Patients with Diabetic Foot

Autologous platelet-rich gel (APG) has emerged as a novel treatment modality for diabetic foot, demonstrating potential in promoting wound healing and tissue repair. Negative pressure drainage has been shown to effectively remove wound exudates and facilitate wound healing. The objective of this research was to demonstrate the clinical efficacy of APG combined with negative pressure drainage in patients with diabetic foot. Following the preparation of platelet-rich plasma (PRP) gel, the influence of various temperatures and centrifugation speeds on gel properties was analyzed. PRP was assessed, and the slope and effective disaggregation rate of PRP were compared. A total of 30 healthy volunteers without diabetic foot were recruited as the control group and randomly assigned into three groups, with 10 participants in each group. The mean volume and concentration of PRP in the three groups were analyzed. A total of 30 patients with diabetic foot were selected as the observation group to analyze the therapeutic effects of APG combined with negative pressure drainage in patients with diabetic foot. The results showed that the prepared separated gel effectively isolated components in the blood, with a decrease in gel viscosity observed with increased centrifugation speed and temperature. The pH of the separated plasma remained stable. The plasma showed the best effects when immediately placed. At 0 h, 3 h, and 6 h, the PRP concentration in Group 1 was drastically superior to the other two groups (P &lt; 0.05). Regarding the slope of PRP, at 30 °C, the slope remained relatively stable; at 25 °C, the slope exhibited the largest variation. At 5 °C, the slope changed between 25 °C and 30 °C. The effective disaggregation rate was lowest when immediately placed, and it gradually increased with the prolongation of placement time. At 30, 60, 90, and 120 minutes of placement, the difference in effective disaggregation rate between 5 °C and 25 °C or 30 °C was considerable (P &lt; 0.05). The pH of PRP at 0 h, 3 h, and 6 h was weakly acidic, with inconsiderable difference in pH values among the three time periods (P &gt; 0.05). At 0 h, 3 h, and 6 h, the PRP concentration in Group 1 was markedly superior to the other two groups (P &lt; 0.05). In summary, the prepared separated gel effectively isolated PRP and the combination of APG with negative pressure drainage demonstrated remarkable therapeutic efficacy in patients with diabetic foot. The adoption of APG provides a personalized and innovative treatment option for diabetic foot patients, offering the potential to improve treatment outcomes.

Case Study of Ozone Bagging Adjuvant Therapy in Wagner II and III Diabetic Foot Ulcers on Wound Healing Process: Three Patients Recovered Completely

Background: Diabetic foot ulcer is a chronic complication of diabetes mellitus in the form of ulceration with or without infection. Diabetic foot ulcers that are not handled properly can cause damage to the foot that requires amputation. Wound care techniques for treating diabetic foot ulcers are starting to develop, one of which is ozone bagging therapy. This ozone bagging therapy in diabetic foot ulcers is reported to be useful as an anti-microbial effect, increasing glycemic control, increasing insulin sensitivity, preventing oxidative stress, increasing fibroblast proliferation, and increasing the release of growth factors. This case study will report 3 patients with Wagner II and III-foot ulcers who healed completely within 28 days using ozone bagging treatment as an adjuvant. Methods: 3 patients with diabetic foot ulcers Wagner II and III received ozone bagging therapy every 4 days for 7 sessions (a total of 28 days) as an additional therapy besides treating moist gauze using NaCl. This study used a Medical Ozone Generator. The dose of ozone used with medical oxygen is 1 lpm, flow 0.6, in the first session "high dose" with an output dose of 80-100 mg/l and in the 2nd-7th session with a low dose (25-35 mg/l). Macroscopic assessment of the wound using the Wagner scale and the progress of each treatment session is documented in photographs. Results: On macroscopic measurements, the process of wound healing leading to wound closure was better in the treatment group and was taken as a case for 3 patients who recovered completely. It resulted in 3 patients who recovered completely with a measurement of the Meggitt-Wagner scale of 0.26. Conclusion: For these recovered patients, there was a decrease in VEGF, TGF-β, and PDGF levels. The VEGF, TGF-β, and PDGF levels tested were VEGF, TGF-β, and PDGF levels in wound exudate by comparing them on the 3rd day. 1st and 12th day. Supported by macroscopic data showing that the wound healing process was better in the group that received ozone bagging therapy as an adjuvant. From this study it was found that the trend of decreasing levels of VEGF, TGF-β, and PDGF in wound exudate occurred because the inflammatory and proliferative processes in the treatment group lasted more faster than the control group. Keywords: ozone bagging therapy, diabetic ulcers, wound exudate, growth factors, VEGF, TGF-β, and PDGF, Meggitt-Wagner scale.

Technical Evaluation of a New Medical Device Based on Rigenase in the Treatment of Chronic Skin Lesions.

Chronic wound is characterized by slow healing time, persistence, and abnormal healing progress. Therefore, serious complications can lead at worst to the tissue removal. In this scenario, there is an urgent need for an ideal dressing capable of high absorbency, moisture retention and antimicrobial properties. Herein we investigate the technical properties of a novel advanced non-woven triple layer gauze imbibed with a cream containing Rigenase, an aqueous extract of Triticum vulgare used for the treatment of skin injuries. To assess the applicability of this system we analyzed the dressing properties by wettability, dehydration, absorbency, Water Vapor Transmission Rate (WVTR), lateral diffusion and microbiological tests. The dressing showed an exudate absorption up to 50%. It created a most environment allowing a proper gaseous exchange as attested by the WVTR and a controlled dehydration rate. The results candidate the new dressing as an ideal medical device for the treatment of the chronic wound repairing process. It acts as a mechanical barrier providing a good management of the bacterial load and proper absorption of abundant wound exudate. Finally, its vertical transmission minimizes horizontal diffusion and side effects on perilesional skin as maceration and bacterial infection.

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

A Shear-Thinning, Self-Healing, Dual-Cross Linked Hydrogel based on Gelatin/Vanillin/Fe3+ /AGP-AgNPs: Synthesis, Antibacterial and Wound-Healing Assessment.

A shear-thinning and self-healing hydrogel based on a gelatin biopolymer was synthesized using vanillin and Fe3+ as dual crosslinking agents. Rheological studies indicate the formation of a strong gel found to be injectable and exhibit rapid self-healing (within 10 minutes). The hydrogels also exhibited a high degree of swelling, suggesting potential as wound dressings since the absorption of large amounts of wound exudate, and optimum moisture levels, lead to accelerated wound healing. Andrographolide, an anti-inflammatory natural product was used to fabricate silver nanoparticles, which were characterized, and composited with the fabricated hydrogels to imbue them with anti-microbial activity. The nanoparticle/hydrogel composites exhibit activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Burkholderia pseudomallei (B. pseudomallei), the pathogen that causes melioidosis, a serious but neglected disease affecting southeast Asia and northern Australia. Finally, the nanoparticle/hydrogel composites are shown to enhance wound closure in animal models compared to the hydrogel alone, confirming that these hydrogel composites hold great potential in the biomedical field. This article is protected by copyright. All rights reserved.

Synthesis, characterization, and potential application of polyurethane foam as an effective alternative for dental aspiration substrate in liquid absorption/retention and mechanical properties

AbstractTooth extraction will leave a wound that may cause blood leakage, and the application of liquid‐absorbing hemostatic cotton pressed on the wound can play the effect of pressure to halt bleeding. Unfortunately, the loose structure of the dental absorbent hemostatic cotton causes local slag to fall. Cotton fiber will impede wound heading and possibly drop into the throat and esophagus, thus impacting the life and health of the patient. Therefore, it is of great significance to prepare a material with toughness and high liquid absorption. The polyurethane foams (PUFs) with different chain extension coefficients synthesized from polyether polyol and diphenylmethane diisocyanate (MDI) with water as the blowing agent have excellent toughness and liquid‐absorbing properties with potential applications. The hydrophilic polyethylene glycol (PEG) is introduced into the polyurethane chain segment to form a synergistic effect with the three‐dimensional foam network structure to absorb more wound exudate. The hydrophobic PUFs can be applied to wounds with less exudate and the hydrophilic PUFs can be applied to chronic wounds with more exudate. The porous structure gives the PUF a strong loading capacity and promotes the wound‐healing effect. The PUFs exhibit good liquid absorption/retention performance in both 0.9 wt% NaCl solution and DI water, especially PUF‐1.10 has an ultimate DI water absorbency of nearly 840%. According to the performance, comparison of the current market commonly used dental absorbent hemostatic cotton; PUF‐1.10 is considered a promising candidate for replacing traditional dental commercial absorbent hemostatic slag‐fall cotton in liquid absorption/retention and mechanical properties.

A Multifunctional Polyethylene Glycol/Triethoxysilane-Modified Polyurethane Foam Dressing with High Absorbency and Antiadhesion Properties Promotes Diabetic Wound Healing.

The delayed healing of chronic wounds, such as diabetic foot ulcers (DFUs), is a clinical problem. Few dressings can promote wound healing by satisfying the demands of chronic wound exudate management and tissue granulation. Therefore, the aim of this study was to prepare a high-absorption polyurethane (PU) foam dressing modified by polyethylene glycol (PEG) and triethoxysilane (APTES) to promote wound healing. PEG-modified (PUE) and PEG/APTES-modified (PUESi) dressings were prepared by self-foaming reactions. Gauze and PolyMem were used as controls. Next, Fourier transform-infrared spectroscopy, thermomechanical analyses, scanning electron microscopy and tensile strength, water absorption, anti-protein absorption, surface dryness and biocompatibility tests were performed for in vitro characterization. Wound healing effects were further investigated in nondiabetic (non-DM) and diabetes mellitus (DM) rat models. The PUE and PUESi groups exhibited better physicochemical properties than the gauze and PolyMem groups. Moreover, PUESi dressing showed better anti-adhesion properties and absorption capacity with deformation. Furthermore, the PUESi dressing shortened the inflammatory phase and enhanced collagen deposition in both the non-DM and DM animal models. To conclude, the PUESi dressing not only was fabricated with a simple and effective strategy but also enhanced wound healing via micronegative-pressure generation by its high absorption compacity with deformation.

Evaluation of DNA lesions and radicals generated by a 233nm far-UVC LED in superficial ex vivo skin wounds.

The application of a far-ultraviolet C (UVC) light emitting diode (LED) of 233nm showed significant bactericidal efficacy at an applied dose between 20 and 80mJcm-2 as reported recently. In addition, only minor epidermal DNA lesions were observed in ex vivo human skin and in vitro epidermal models <10% of the minimal erythema dose of UVB radiation. To broaden the potential range of applications of such systems, e.g. to include postoperative application on wounds for the purpose of decontamination, we assessed how a disruption of normal anatomic skin structure and function influences the skin damage induced by light from 233nm far-UVC LEDs. Thus, we induced superficial skin wounds by mechanical detachment of the stratum corneum in ex vivo human skin. Barrier-disruption of the skin could be successfully determined by measuring an increase in the transepidermal water loss (TEWL) and the stratum corneum loss could be determined morphologically by 2-photon microscopy (2-PM). After far-UVC irradiation of the skin, we screened the tissue for the development of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs). The abundance of DNA lesions was elevated in wound skin in comparison to intact skin after irradiation with far-UVC. However, no increase in DNA lesions was detected when artificial wound exudate consisting of cell culture medium and serum was applied to the disrupted skin surface prior to irradiation. This effect agrees with the results of ray tracing simulations of the absorption of far-UVC light incident on a superficial skin wound. Interestingly, no significant deviations in radical formation between intact skin and superficially wounded skin were detected after far-UVC irradiation as analyzed by electron paramagnetic resonance (EPR) spectroscopy. In conclusion, 233nm LED light at a dose of 60mJ/cm2 could be applied safely on superficial wounds for the purpose of skin antisepsis as long as the wounds are covered with wound fluid.

Biodegradable trimethyl chitosan nanofiber mats by electrospinning as bioabsorbable dressings for wound closure and healing

The paper aimed to prepare quaternary chitosan-based nanofibers as bioabsorbable wound dressings. To this aim, fully biodegradable chitosan/N,N,N-trimethyl chitosan (TMC) nanofibers were designed and prepared via electrospinning, using poly(ethylene glycol) as sacrificial additive. The new biomaterials were structurally and morphologically characterized by FTIR and NMR spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy, and their properties required for wound dressings application were investigated and discussed in detail. Thus, the nanofiber behavior was investigated by swelling, dynamic vapor sorption, and in vitro biodegradation in media mimicking the wound exudate. The mechanical properties were analysed from the stress-strain curves, the bioadhesivity from the texture analysis and the mucoadhesivity from the Zeta potential and transmittance measurements. The antimicrobial activity was assessed against S. aureus and E. coli strains, and the biocompatibility was tested in vitro on normal human dermal fibroblasts, and in vivo on rats. The application of the fiber mats with the best balance of properties as dressings on deep burn wound models in rats showed wound closure and active healing, with fully restoration of epithelia. It was concluded that the combination of chitosan with TMC into nanofibers provides new potential bioabsorbable wound dressing, opening new perspectives in regenerative medicine.