The Antibacterial Properties of Silver Dressings and Their Application in Wound Healing

Silver-containing dressings have gained popularity in clinical applications due to their exceptional antibacterial properties and ability to enhance wound healing.These dressings primarily exert their antibacterial effects through the utilization of silver ions or nano-silver particles.The antimicrobial property of silver ions is a result of multiple mechanisms,with the most significant being the interaction between Ag or Ag+and the bacterial cell wall,as well as the interaction between Ag+and bacterial DNA or RNA,which inhibits replication and division.Silver-containing dressings can effectively reduce inflammation in wound tissue and expedite wound healing.The antibacterial and wound-healing promoting effects of these dressings are closely associated with the controlled release rate of silver ions.Consequently,developing novel silver-containing dressings that accurately regulate this release rate has become a prominent area of research interest.With broad prospects for application in wound care,silver-containing dressings are anticipated to offer innovative solutions for addressing numerous challenges encountered in clinical wound management.

Spatially engineering tri-layer nanofiber dressings featuring asymmetric wettability for wound healing

Inspired by the skin structure,an asymmetric wettability tri-layer nanofiber membrane(TNM)consisting of hydrophilic inner layer loaded with lidocaine hydrochloride(LID),hydrophobic middle layer with ciprofloxacin(CIP)and hydrophobic outer layer has been created.The hydrophobic outer layer endows the TNM with waterproof function and anti-adhesion from contaminants.The hydrophobic middle layer with CIP preserves long-term inhibition of bacteria growth and the hydrophilic inner layer with LID possesses optimal waterabsorbing capacity and air permeability.The TNM dramatically elevates the water contact angles from 10°(inner layer)to 120(outer layer),indicating an asymmetric wettability,which could directionally transport wound exudate within the materials and meanwhile maintain a comfortable and moist environment to promote wound healing.Furthermore,the sequential release of LID and CIP could relieve pain rapidly and achieve antibacterial effect in the long run,respectively.In addition,the TNM shows superior biocompatibility towards L929 cells.The in vivo results show the TNM could prevent infection,accelerate epithelial regeneration and significantly accelerate wound healing.This study indicates the developed TNM with asymmetrical wettability and synergetic drug release shows great potential as a wound dressing in clinical application.

Improving pressure ulcer care in intensive care units:Evaluating the impact of bundled care and silver nanoparticle dressings

BACKGROUND Pressure ulcer(PU)are prevalent among critically ill trauma patients,posing substantial risks.Bundled care strategies and silver nanoparticle dressings offer potential solutions,yet their combined effectiveness and impact on patient satisfaction remain insufficiently investigated.AIM To assess the impact of bundled care along with silver nanoparticle dressing on PUs management and family satisfaction in critically ill trauma patients.METHODS A total of 98 critically ill trauma patients with PUs in intensive care unit(ICU)were included in this study.Patients were randomly assigned to either the control group(conventional care with silver nanoparticle dressing,n=49)or the intervention group(bundled care with silver nanoparticle dressing,n=49).The PU Scale for Healing(PUSH)tool was used to monitor changes in status of pressure injuries over time.Assessments were conducted at various time points:Baseline(day 0)and subsequent assessments on day 3,day 6,day 9,and day 12.Family satisfaction was assessed using the Family Satisfaction ICU 24 ques-tionnaire.RESULTS No significant differences in baseline characteristics were observed between the two groups.In the intervention group,there were significant reductions in total PUSH scores over the assessment period.Specifically,surface area,exudate,and tissue type parameters all showed significant improvements compared to the control group.Family satisfaction with care and decision-making was notably higher in the intervention group.Overall family satisfaction was significantly better in the intervention group.CONCLUSION Bundled care in combination with silver nanoparticle dressings effectively alleviated PUs and enhances family satisfaction in critically ill trauma patients.This approach holds promise for improving PUs management in the ICU,benefiting both patients and their families.

Long-term Antibacterial Properties and Bond Strength of Experimental Nano Silver-containing Orthodontic Cements

The purpose of this study was to evaluate the long time antibacterial properties and shear bond strength of experimental nano silver-containing cements （NSC）. Nano silver base inorganic antibacterial powder was added to the reinforced glass ionomer cement at five different weight ratios to obtain a series of nano silver-containing cements, then the antibacterial properties of three orthodontic cement products and five NSC samples were evaluated by the direct contact test （DCT） and the agar diffusion test （ADT）. The DCT, which was based on turbidness determination of bacterial growth in 96-well microtiter plates, was performed in both fresh and aged for 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks tested materials. The shear bond strengthes of three orthodontic cement products and five NSC samples were examined using a universal testing machine. The ADT results indicated that there were no significant differences between NSCs and ORTHO LC fresh specimens. In the DCT experiment, all fresh silver nanoparticles-containing tested samples presented powerful antibacterial properties, but they gradually lost the effective antimicrobial agents with the extension of aging time. Finally, none of the tested materials maintained its antibacterial property after aging for 8 weeks. A gradually decreasing trend of bond strength presented with the increasing incorporation of nano silver base inorganic antibacterial powder into the glass ionomer cement, even though all the tested material specimens reached the ideal bond strength range. We may conclude that NSCs can contribute to decrease the demineralization rate around brackets without compromising bond strength.

Electrospun antibacterial nanofibers for wound dressings and tissue medicinal fields:A Review

Bacterial infections are a major cause of chronic infections.Thus,antibacterial material is an urgent need in clinics.Antibacterial nanofibers,with expansive surface area,enable efficient incorporation of antibacterial agents.Meanwhile,structure similar to the extracellular matrix can accelerate cell growth.Electrospinning,the most widely used technique to fabricate nanofiber,is often used in many biomedical applications including drug delivery,regenerative medicine,wound healing and so on.Thus,this review provides an overview of all recently published studies on the development of electrospun antibacterial nanofibers in wound dressings and tissue me-dicinal fields.This reviewer begins with a brief introduction of electrospinning process and then discusses electrospun fibers by incorporating various types of antimicrobial agents used as in wound dressings and tissue.Finally,we finish with conclusions and further perspectives on electrospun antibacterial nanofibers as 2D biomedicine materials.

Antibacterial Properties of Nano Silver-containing Orthodontic Cements in the Rat Caries Disease Model

The purpose of this study was to evaluate the antibacterial properties of experimental nano silver-containing cements（NSCs） using rat caries disease model. Nano silver base inorganic antibacterial powder was added to the reinforced glass ionomer cement at three different weight ratios to obtain a series of nano silver-containing cements, then two orthodontic cement products and three NSC samples were implanted into rat caries disease model, and their antibacterial properties were evaluated by the scanning electron microscope（SEM）. Moreover, the rat caries disease model were established by inoculating cariogenic bacteria S mutans into antibiotics treated rat mouths and feeding with cariogenic diet. The tested materials were bonded on the surface of the buccal half crowns of the upper fi rst premolar, and then fi xed under the rats＇ front teeth lingual side to acquire enough retention. The SEM results indicated that the growth of streptococcus mutans was very active in group of Transbond XT. One month later, S mutans scattered on the GC Fuji ORTHO LC surface, and then the number signifi cantly increased and arranged in chains after three months. In groups of NSC2, NSC3 and NSC4, the number of S mutans presented the downward trend and tended to disperse individually with the increase of silver nanoparticle content. We may conclude that the incorporation of silver nanoparticle enhanced GC Fuji ORTHO LC the adhesion restrain and killing effect to S mutans.

Effect of vacuum sealing drainage combined with biological dressings on the angiogenesis and inflammatory response after diabetic foot ulcer wound grafting

Objective: To study the effect of vacuum sealing drainage combined with biological dressings on the angiogenesis and inflammatory response after diabetic foot ulcer wound grafting. Methods: Patients with diabetic foot who were treated in Sichuan Provincial People's Hospital between May 2014 and February 2017 were selected and randomly divided into vacuum drainage group and normal control group who received vacuum sealing drainage combined with biological dressings as well as conventional debridement and dressing change to deal with the wound respectively. Before treatment as well as 1 d, 3 d and 5 d after treatment, the wound tissue was collected to determine the expression of angiogenesis molecules, angiogenesis signaling pathway molecules and inflammatory response molecules. Results: 1 d, 3 d and 5 d after treatment, VEGF, VEGFR, CD105, MMP9, PI3K, AKT, cyclinD1, p38MAPK and NF-kB protein expression in wound tissue of vacuum drainage group were significantly higher than those of normal control group while COX-2, iNOS, TNF-α and IL-6 mRNA expression were significantly lower than those of normal control group. Conclusion: Vacuum sealing drainage combined with biological dressings promotes the angiogenesis and inhibits the inflammatory response after diabetic foot ulcer wound grafting.

Application Experience of Moist Wound Healing Theory Combined with Modern New Dressings in the Treatment of Pressure Ulcers

Objective:Research on the effect of moist wound healing theory in a combination with modern new dressing treatment in patients diagnosed with pressure ulcers.Method:Selected 30 patients with pressure ulcers from our hospital,which is Shandong Tai an Municipal Hospital,from January 2019 to January 2021 were divided into experimental group(15 cases,treated with moist wound healing theory combined with modern new dressings)and control group(15 cases,applied conventional treatments).The treatment effect,time of wound edema subsidence,wound healing time,number of dressing changes,granulation tissue growth time,and diameter reduction time were compared between the two groups.Results:The total effective rate of the experimental group(93.33%,14/15)was higher than that of the control group(53.33%,8/15),P<0.05;the time to subsidence of wound edema in the experimental group was(3.11±0.22),and the time for wound healing was(12.78±0.45),the number of dressing changes(7.13±0.34)times,the growth time of granulation tissue(5.43±2.22),the diameter reduction time(6.25±3.75),compared with the control group,P<0.05.Conclusion:In the clinical treatment of patients diagnosed with pressure ulcers,the effective combination of moist healing theory and modern new dressing therapy has significant effects,whereby it speeds up the healing process of the pressure ulcers,and it is proven to be worthy to be promoted for usage.

Stability of Bitter Orange Juice-Olive Oil Salad Dressings Stabilized with Polysaccharides

Emulsifying properties of bitter orange （Citrus aurantium） juice-olive oil salad dressings stabilized with different polysaccharides were investigated. Oil-in-water emulsions （50：50, v/v） were prepared with bitter orange juice-olive oil in the presence of various concentrations （0.1%-1.0%, w/v） of pectin or guar gum or iota-（t-）carrageenan and then these emulsions were homogenized. Emulsion activity index （EAI） and emulsion stability index （ESI） were determined spectrophotometrically by measuring time-dependent changes in turbidity. Creaming stability of emulsions was followed by visual observation of serum layer with respect to time. Microstructures of emulsions were examined by using polarized light microscopy. The addition of polysaccharides improved emulsion stability and emulsions containing higher amounts of polysaccharide were more stable against creaming. Microscopic observations showed that emulsions containing polysaccharides had small droplets as compared to that of emulsions without polysaccharides and emulsions were flocculated due to the presence of polysaccharides. Larger droplets and creaming were observed when the polysaccharide concentration was not sufficient for coverage.

Functionalization of carbopol with NVP for designing antibiotic drug loaded hydrogel dressings for better wound management

In the present work an attempt has been made to design the antibiotic drug loaded carbopolpoly( NVP) based hydrogel wound dressings for better wound care. The polymer films were characterized by SEM-EDX, AFM, FTIR, 13CNMR, TGA/DTA/DTG, DSC, and swelling studies. Besides drug release, various biomedical properties (viz. blood compatibility, mucoadhesion, oxygen permeability, water vapour transmission rate, microbial penetration, tensile strength, bursting strength, resilience, stress relaxation, and folding endurance) have also been studied. The polymer films have been observed to be biocompatible, permeable to oxygen and water vapour and have absorbed simulated wound fluid 11.37±0.31g/g of polymer film. The drug release profile followed the Case-II diffusion mechanism and release profile best fitted in Hixson-Crowell’s kinetic models. Mechanical properties results showed that the polymer film had 0.65±0.12 Nmm??2 tensile strength, 119.38±14.26% elongationand 25.49±0.72% resilience.

Dressing Mechanism and Evaluations of Grinding Performance with Porous cBN Grinding Wheels

Cubic boron nitride(cBN)grinding wheels play a pivotal role in precision machining,serving as indispensable tools for achieving exceptional surface quality.Ensuring the sharpness of cBN grains and optimizing the grinding wheel’s chip storage capacity are critical factors.This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method.It investigates the impact of blasting parameters-specifically silicon carbide(SiC)abrasive size,blasting distance,and blasting time-on the erosive wear characteristics of both the metal bond and abrasive.The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond.Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains,optimal parameters for the working layer are determined:a blasting distance of 60 mm,a blasting time of 15 s,and SiC particle size of 100#.Furthermore,an advanced simulation model investigates the dressing process of abrasive blasting,revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains,thereby enhancing fracture toughness and impact resistance.Additionally,a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels.The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force,temperature,and chip adhesion,thereby enhancing the surface quality of the workpiece.

Industrial utilization of arsenic-containing gold dressing tailings as pellet prepared by straight grate process

The utilization of arsenic-containing gold dressing tailings is an urgent issue faced by gold production companies worldwide.The thermodynamic analysis results indicate that ferrous arsenate(FeAsO_(4)),pyrite(FeS_(2))and sodium cyanide(NaCN)in the arsenic-containing gold metallurgical tailings can be effectively removed using straight grate process,and the removal of pyrite and sodium cyanide is basically completed during the preheating stage,while the removal of ferrous arsenate requires the roasting stage.The pellets undergo a transformation from magnetite to hematite during the preheating process,and are solidified through micro-crystalline bonding and high-temperature recrystallization of hematite(Fe_(2)O_(3))during the roasting process.Ultimately,pellets with removal rates of 80.77% for arsenic,88.78% for sulfur,and 99.88% for cyanide are obtained,as well as the iron content is 61.1% and the compressive strength is 3071 N,meeting the requirements for blast furnace burden.This study provides an industrially feasible method for treating arsenic-containing gold smelting tailings,benefiting gold production enterprises.

Janus hydrogel/electrospun-membrane dressing enhancing wound healing in rats

Background:Excessive exudate secreted from chronic wounds often leads to overhydration and infection.Although a variety of dressings are currently available in clinical applications,they frequently fail to provide multifunction to promote chronic wound healing.The dressings with a Janus structure,featuring distinct properties on each side,are potential to improve wound healing.Methods:Composite dressings with a Janus structure were fabricated,comprising freeze-dried polycaprolactone(PCL)electrospun membrane and alginate-based hydrogel.The PCL fibrous membrane provided air permeability,while the hydrogel loaded with Deferoxamine,composed of alginate and poly(N-isopropylacrylamide)(PNIPAM),exhibited hygroscopic properties.The inclusion of PNIPAM imparted thermo-responsivity.Results:The hydrogel(thickness of 2.778±0.082 mm)exhibited a robust adhesion to the fiber membrane(thickness of 0.261±0.041 mm).For ANDC(Alginate-PNIPAM hydrogel with Deferoxamine/PCL membrane)samples,the water vapor transmission rate(WVTR)was measured to be 3364.80±23.23 g∙m−2∙day−1 and the swelling ratio at 2 h was determined to be 1179±125%.The thermo-responsivity of ANDC samples manifested in an increased swelling rate,escalating from 797±189%at 37°C to 1132±147%at 4°C.The elastic modulus was assessed for lyophilized and rehydrated ANDC sample.When theωof the rheometer rotor was decreased from 10 rad/s to 0.1 rad/s,the lyophilized dressing exhibited a decrease from 2.65±0.01 MPa to 1.80±0.90 MPa,while the rehydrated dressing demonstrated an increase from 133.65±55.68 Pa to 264.23±141.71 Pa.The pro-healing properties of the dressings were evaluated using full-thickness skin defect model on SD rats,and a circular wound of diameter 10 mm healed completely by day 12.Conclusion:The dressings not only protected the wound and absorbed excess exudate,but also demonstrated nondestructive peelability upon cooling,providing a novel approach for accelerating wound healing and management.

Antibacterial and angiogenic dual-functional fibrous membrane dressing for infected wound healing

Background:Skin,being a vital organ that regulates physiological responses in the human body,is prone to injury from external environmental factors.Healing full-thickness skin defects becomes especially challenging when infections and vascular injuries are involved.Traditional wound dressings with single functions,such as antibacterial or angiogenic properties,fall short in achieving rapid wound healing.To address this,there is a need to develop wound dressing materials that possess both effective antibacterial and angiogenic properties.Methods:In this study,we utilized electrospinning technology to fabricate hyaluronic acid-cellulose acetate fibrous membrane dressings,incorporating poly(ionic liquid)as an antibacterial polymer and deferoxamine as an angiogenic agent.Results:The resulting fibrous membrane dressing contained poly(ionic liquid)and deferoxamin showcased a microporous structure,drug-releasing capabilities,and excellent air permeability.It not only demonstrated highly effective antibacterial properties but also exhibited remarkable angiogenesis,thereby promoting the healing of full-thickness skin defect wounds in both in vitro and in vivo assays.Conclusion:These findings highlight the immense potential of this wound dressing material for future clinical applications.

高性能慢性伤口敷料的研究进展

慢性伤口愈合是一个复杂且耗时的过程,容易受到大肠杆菌、金黄色葡萄球菌等微生物的攻击.传统敷料如棉花、纱布等,其屏障作用较差,导致伤口容易被细菌侵入,在愈合过程中其纤维会黏附在新生的肉芽组织上,频繁换药会加剧患者痛苦甚至导致二次创伤,并且对创面愈合无明显促进作用.近十年来,新型创面敷料的相关研究不断涌现,这些敷料可以与伤口相互作用,其中的智能敷料还可以通过内置传感器或智能材料(如刺激响应材料和自修复材料)感知和反应伤口状况或环境变化,赋予伤口敷料智能响应释药的功能,从而有效促进伤口愈合.基于此,综述伤口敷料领域的研究进展,同时总结相关性能表征方法,并简要展望该领域的未来研究方向.

自体刃厚头皮回植修复中厚供皮区创面的安全有效性

背景:大面积深度烧伤创面愈合后多伴瘢痕增生,需要移植中厚皮进行修复,所取中厚皮片一般达到真皮乳头层以下,若处理不当容易出现供区皮创面愈合延迟、溃破和愈合后疼痛瘙痒等并发症,因此,供皮区创面修复应得到重视。目的:分析自体头皮修复深度烧伤和瘢痕患者供皮区的安全性和实用性。方法:选择2021年1月至2023年9月郑州市第一人民医院烧伤科收治的60例深度烧伤和瘢痕增生患者作为研究对象,均进行中厚皮移植修复,取皮部位为患者自身腿部或背部中厚皮,采用随机数字表法分为研究组(30例)、对照组(30例),研究组采用自体刃厚头皮回植修复中厚皮供皮区,对照组采用吸水敷料修复中厚皮供皮区。对比两组术后6 d的中厚皮供皮区创面愈合率、创面完全上皮化时间,术后3,6 d供皮区换药疼痛评分,以及术后6个月中厚皮供皮区瘢痕增生情况。结果与结论:①研究组中厚皮供皮区创面上皮化时间短于对照组(P<0.05),中厚皮供皮区创面愈合率高于对照组(P<0.05),术后3,6 d的中厚皮供皮区换药疼痛评分均低于对照组(P<0.05),术后6个月的中厚皮供皮区瘢痕增生率、瘢痕评分及瘙痒评分均低于对照组(P<0.05);②结果表明,自体头皮修复中厚皮供皮区具有加快创面愈合和减轻瘢痕增生的优点。

传统马面裙形制结构考释及其现代设计思辨

基于文化自信与传统文化振兴的背景下,马面裙代表着中国优秀的传统文化走进大众视野、走向国际舞台。文章纵向整理马面裙发展的历史脉络、横向梳理马面裙的款式差别,同时立足现代服装设计,对于马面裙从平面结构的对比到立体形态的差异进行拓展研究。采用实验法、比较研究法,将马面裙实物数据为基础样本,进行实物复原和形制特征记录。同时依据现代裙装结构制版方法,进行相同数据的多样本制作和横向的形制比对。采用概率逻辑分析,从平面结构的比对到立体形态的差异进行拓展分析。通过对比实验结果,就马面裙的结构复原、改良方案和创新视角展开设计思辨。

美国亚裔文学中的徐志摩形象——以《小脚与西服》《中国珍珠》《从东到西》三部小说为中心

以《小脚与西服》《中国珍珠》《从东到西》三部美国亚裔文学作品为中心,分析了不同作者从不同角度塑造的徐志摩形象:在传统与现代间挣扎的冷漠才子、倾心于知识女性的浪漫诗人、胸怀救国之志的浪漫主义者。《小脚与西服》从家族叙事的角度,在肯定徐志摩才华和志向的同时,揭示其在婚恋中自私冷漠、缺乏责任心的一面;《中国珍珠》对徐志摩和赛珍珠的爱情传闻进行文学加工,体现了徐志摩对知识女性的尊重和仰慕;《从东到西》秉持男性立场,着重表现徐志摩的风流多情和救国志向。这三个文本中的徐志摩形象丰富了外国文学中的华人形象,解构了美国白人文学中传统刻板化的华人男性形象,有助于外国读者通过徐志摩进一步了解中国文学和文化。

三能级原子Dressed态下的压缩

本文通过求解级联型三能级原子部分哈密顿量的本征值问题,得到自发辐射的级联型三能级原子的Dressed态。加入基态后,得到场方差一般表达式,并求出初始条件下的压缩最佳值。

Dressed原子与多模弱压缩光场的单光子相互作用

采用dressed原子的方法,处理了dressed原子与多模压缩光场之间的单光子相互作用。计算了各dressed原子本征态之间的跃迁速率,并讨论了在稳定时,弱光场的存在对共振荧光的影响以及dressed原子对弱光场的吸收和辐射。