Silver percutaneous absorption after exposure to silver nanoparticles: A comparison study of three human skin graft samples used for clinical applications

Silver nanoparticles (AgNPs) are increasingly applied to a wide range of materials for biomedical use. These enable a close contact with human skin, thanks to the large release of silver ions that is responsible for a broad spectrum of antimicrobial activity. Silver can permeate the skin; however, there are no data available on silver permeation through skin grafts commonly used in burns recovery. The aim of our study was to evaluate silver penetration using fresh, cryopreserved, and glycerolized human skin grafts after exposure to a suspension of AgNPs in synthetic sweat using a Franz diffusion cell apparatus for 24 h.Silver permeation profiles revealed a significantly higher permeation through glycerolized skin compared with both fresh and cryopreserved skin: 24-h silver flux penetration was 0.2 ng cm⁻² h⁻¹ (lag time: 8.2 h) for fresh skin, 0.3 ng cm⁻² h⁻¹ (lag time: 10.9 h) for cryopreserved skin, and 3.8 ng cm⁻² h⁻¹ (lag time: 6.3 h) for glycerolized skin.Permeation through glycerolized skin is significantly higher compared to both fresh and cryopreserved skin. This result can generate relevant clinical implications for burns treatment with products containing AgNPs.     

Silver nanoparticle-coated suture effectively reduces inflammation and improves mechanical strength at intestinal anastomosis in mice

Background

Our previous studies have revealed that silver nanoparticles (AgNPs) had anti-inflammatory properties. In this study, we coated AgNPs onto the surface of absorbable suture, to further explore their anti-inflammatory efficacy and potential clinical application using an intestinal anastomosis model.

Methods

Layer-by-layer deposition was used to coat AgNPs on absorbable sutures. Scanning electron microscopy (SEM) was conducted to observe the morphology and distribution of AgNPs on suture surface. 1 cm of either non-coated suture, suture coated with antibiotics or AgNPs-coated suture was placed on E. coli overlay of LB agar plates to test for bacterial inhibition. The respective sutures were then used for ileal anastomosis in mice. The anastomotic sites were harvested to investigate the degree of tissue inflammation and cell proliferation, as well as collagen deposition. Furthermore, burst pressure measurement was employed to test for mechanical properties.

Results

SEM observation indicated AgNPs could be immobilized and distributed on suture surface evenly. AgNPs-coated suture had the best in vitro anti-bacterial efficacy when compared with other groups. Subsequent immunohistochemistry in the intestinal anastomosis model showed significantly less inflammatory cell infiltration (macrophage and neutrophil) and better collagen deposition in the anastomotic tissue in the AgNPs-coated suture group. Burst pressure measurement in healed anastomosis further confirmed that AgNPs-coated suture had better mechanical properties.

Conclusion

Our study suggests that AgNPs-coated sutures can improve anastomosis healing due to better mechanical properties from reduced inflammation.     

Three dimensional (3D) modelling and surgical planning in trauma and orthopaedics

IntroductionThree dimensional (3D) modelling facilitates visualization, manipulation, and analysis of image data, the three dimensional format of such image, allows a better appreciation of the geometry, size, and exact relationship between diseased and normal tissue. The role in orthopaedic surgical planning is highlighted.DiscussionSurgical procedures in orthopaedics and trauma rely on imaging, which in addition to making the diagnosis also assist in planning the elected surgical procedure through to a successful execution.In the area of trauma management, the use of 3D modelling eases the execution of fracture operative approach, reduction and appropriate fixation, especially in complex fractures, like in the acetabulum. Post trauma correction of deformities is made easier using 3D modelling in the preoperative surgical planning.For the purposes of tumour excision, a more acceptable margin of excision can be planned and successfully implemented.There is an increasing role for computer assisted procedures in arthroplasty, the use of a 3D image for preoperative planning promises to deliver patient specific bone cut in dimensions that will allow less of inappropriate loading thereby promoting longevity of the implant especially in younger patients.ConclusionThe processes for acquiring 3D images need to be made simpler and easier to gain more widespread use in orthopaedics and trauma.     

创伤骨科基础研究有关新进展

创伤骨科的临床救治成活率近年提高较快,但成活后的功能恢复率并不满意。为此,应进一步加强有关基础理论研究。创伤骨科基础研究范围广泛,近年出现的较新进展有数字化虚拟人体在教学、科研和临床上的应用;生物力学研究从常用的实测技术方法向理论模拟的有限元发展;创伤早期救治的分子生物学探索;骨质疏松的药理学基础研究;用组织工程学理论和技术寻找新的创伤缺损修复材料来源。     

Studies on the biocompatibility and the interaction of silver nanoparticles with human mesenchymal stem cells (hMSCs)

Purpose  Silver nanoparticles (Ag-NPs) are widely used in different areas, e.g., in the food, electronic, or clothing industry due to well-known slow-release antiseptic activities. Despite the widespread use of nanosilver, there is a serious lack of information concerning the biological activities of nanosilver on human tissue cells. Materials and methods  In this study, the influence of spherical Ag-NPs (diameter about 100 nm) on the biological functions (proliferation, cytokine release, and chemotaxis) of human mesenchymal stem cells (hMSCs) was analyzed. Results  The results showed a concentration-dependent activation of hMSCs at nanosilver levels of 2.5 μg mL⁻¹, and cytotoxic cell reactions occurred at Ag-NPs concentrations above 5 μg mL⁻¹. Cell proliferation and the chemotaxis of hMSC both decreased with increasing Ag-NPs concentrations. Different effects on the cytokine release from hMSCs were observed in the presence of Ag-NPs and Ag⁺ ions. The release of IL-8 was significantly increased at high but noncytotoxic concentrations of Ag-NPs (2.5 μg mL⁻¹). In contrast, the levels of IL-6 and VEGF were concomitantly decreased compared to the control group. The synthesis of IL-11 was not affected at different Ag-NP concentrations. The agglomeration tendency of Ag-NPs in different biological media increased with a high electrolyte content, e.g., in RPMI. However, complexation with fetal calf serum in the cell culture media stabilized the Ag-NPs against agglomeration. Conclusion  In summary, the results showed that Ag-NPs exert cytotoxic effects on hMSCs at high concentrations but also induce cell activation (as analyzed by the release of IL-8) at high but nontoxic concentrations of nanosilver. “Best of Abstracts – Chirurgisches Forum 2009, Deutsche Gesellschaft für Chirurgie”     

Silver resistance in MRSA isolated from wound and nasal sources in humans and animals

Methicillin‐resistant Staphylococcusaureus (MRSA) colonises skin, nasal passages and dermal wounds. Methods used to manage wounds infected and colonised with MRSA often include the use of topical antiseptics such as ionic silver and iodine. The objectives of this study were to determine the prevalence of silver‐resistance (sil) genes in MRSA and methicillin‐resistant coagulase‐negative staphylococci (MR‐CNS) isolated from wounds and nasal cavities of humans and animals, and also to determine the susceptibility of sil‐positive and sil‐negative MRSA isolates to a silver‐containing Hydrofiber^® (SCH) wound dressing, on planktonic silE‐positive and silE‐negative MRSA. Polymerase chain reaction was used to determine the presence of three silver‐resistance (sil) genes, silE, silP and silS in 33 MRSA and 8 methicillin‐resistant staphylococci (MR‐CNS). SilP and silS genes were absent in all isolates tested; however, two MRSA strains were found to contain the silE gene, together with one isolate of MR‐CNS. Phenotypic resistance of the silE‐positive strains and their susceptibility to the SCH dressing was evaluated using the zone of inhibition test on Mueller Hinton agar, and confocal laser microscopy using a live/dead fluorescent stain. Results confirmed that the SCH dressing was effective in killing all MRSA strains with and without the silE gene. First, this study showed that the prevalence of sil genes was low in the isolates investigated; and secondly, that the presence of a silver‐resistance gene (silE) in MRSA and MR‐CNS did not afford protection to the organism in the presence of a SCH wound dressing. The use of topical antiseptics in chronic wound care should be considered before the use of antibiotics that can result in their overuse and the risk of further resistance.     

A Comparative Study of the Burn Wound Healing Properties of Saline-Soaked Dressing and Silver Sulfadiazine in Rats

The purpose of this study was to further investigate that phenomenon and to explore the effect silver sulfadiazine on wound healing. Full-thickness burn wounds were created on the dorsum of Wistar albino rats under anesthesia. The wounds were treated with silver sulfadiazine and saline-soaked dressing for fourteen days, and then observed until healed. Wound surface area was measured each three days. Time to 50% and 90% healing was compared. No clinical infections occurred. Wound half-life and healing times were shortest in the saline-soaked group (P < 0.0001) in full-thickness burns. Wound contraction was delayed by silver sulfadiazine. These data suggest that silver sulfadiazine retard burn wound healing. Infection control without delay of burn wound healing is most appealing and clinical trials are planned.     

To admit or not: the use of camera mobile phone in trauma and orthopaedics at night

Introduction  Mobile phones with incorporated digital cameras have become increasingly sophisticated. Their use in transmitting images for clinical decision making has been described in Otolaryngology, Neurosurgery, and Plastic Surgery, but not in the field of trauma and orthopaedics in the National Health Service (NHS) setting. Case report  We describe the use of a mobile phone and multimedia messaging to guide the management of a patient with a distal radius fracture. A junior SHO was asked to give an orthopaedic opinion on the post manipulation X-rays at night. A camera phone was used to take pictures of the X-rays and send them as a multimedia message (MMS) to the non resident orthopaedic registrar to decide on the appropriate management. The post manipulation position was not deemed to be acceptable by the registrar after viewing the MMS and the patient was admitted for surgical intervention. Discussion  This mode of communication may become more popular with change in working practices in the foreseeable future. However, it is important to monitor the use of this new technology to ensure its appropriate use. Senior clinicians should still be available to review the patients and the X-rays in traditional manner to reach appropriate management plan, even at night.     

Use of bone marrow derived stem cells in trauma and orthopaedics: A review of current concepts

There is a considerable amount of interest in the future role of bone marrow-derived stem cells (BMDSCs) and tissue engineering techniques to manage conditions within the musculoskeletal system. Repair of soft tissue and bone defects, in the early stages of injury, may lead to a reduction in progression of symptoms. Furthermore, troublesome soft tissue injuries that are notoriously fraught with problems either in healing or function, could be augmented with such techniques. The aim of this review paper is to look at the advances in such strategies to tackle these problems and assess how BMDSCs, with the aid of growth factors and scaffolds, are being used in vitro, animal and even human models to treat problems within the field of trauma and orthopaedics. There is plenty of evidence that the results are encouraging and thus gaining momentum toward their use in human studies.     

Comparative study of Silver Sulfadiazine with other materials for healing and infection prevention in burns: A systematic review and meta-analysis

The aim of this systematic review with meta-analysis was to compare the effect of Silver Sulfadiazine (SSD) with other new dressings, with or without silver, on healing and infection prevention in burns. The electronic search was carried out in the electronic databases of Pubmed, ScienceDirect, Lilacs and BVS. The articles included were randomized clinical trials about burn treatment with SSD, which evaluated the healing and infection of burn wounds in humans. The exclusion criteria included articles, editorials and letters published in the form of abstracts, unpublished reports and case series, cross-sectional, observational experimental studies, and the use of sulfadiazine for other types of wounds. The search identified 873 references, and 24 studies were included in accordance with the eligibility criteria. The results showed a statistically favorable difference related to the time of healing for silver dressings (p < 0.0001; MD 3.83; 95% CI 2.03–5.62) and dressings without silver (p < 0.007; MD 2.9; 95% CI 0.81–5.00) in comparison with SSD. The rate of infection showed no difference in the group treated with SSD compared with the group treated with dressings containing silver (p > 0.05). The rate of infection was significantly higher in the SSD group compared with the group treated with dressings without silver (p < 0.005; MD 25.29% and MD 12.97%). Considering the clinical trials conducted up to the present time, the authors concluded that new dressings with and without silver show better results than SSD for wound healing, and burns treated with dressings without silver are less likely to become infected than burns with SSD. No differences between SSD and new silver materials were observed in relation to infection prevention.     

Molecular characterization of multidrug-resistant (MDR) Pseudomonas aeruginosa isolated in a burn center

Objective

The aim of this study was to characterize molecularly multidrug-resistant (MDR) Pseudomonas aeruginosa isolates collected from burn center (BC) patients and environment in a hospital localized in Rio de Janeiro city, RJ, Brazil.

Bacteriophage therapy in infection after fracture fixation (IAFF) in orthopaedic surgery

Infection after fracture fixation (IAFF) in orthopaedic surgery is a significant complication that can lead to disability due to chronic infection and/or relapsing disease, non-union necessitating revision surgery. Management of IAFF is a major challenge facing orthopaedic surgeons across the world due to two key pathogenic mechanisms of Biofilm formation and antimicrobial resistance (AMR) against traditional antibiotics. Advanced prophylactic and treatment strategies to help eradicate established infections and prevent the development of such infections are necessary. Bacteriophage therapy represents an innovative modality to treat IAFF due to multi-drug resistant organisms. We assess the current role and potential therapeutic applications of the novel bacteriophage therapy in the management of these recalcitrant infections to achieve a successful outcome.     

A modified Kampala trauma score (KTS) effectively predicts mortality in trauma patients

BackgroundMortality prediction in trauma patients has relied upon injury severity scoring tools focused on anatomical injury. This study sought to examine whether an injury severity scoring system which includes physiologic data performs as well as anatomic injury scores in mortality prediction.MethodsUsing data collected from 18 Level I trauma centers and 51 non-trauma center hospitals in the US, anatomy based injury severity scores (ISS), new injury severity scores (NISS) were calculated as were scores based on a modified version of the physiology-based Kampala trauma score (KTS). Because pre-hospital intubation, when required, is standard of care in the US, a modified KTS was calculated excluding respiratory rate. The predictive ability of the modified KTS for mortality was compared with the ISS and NISS using receiver operating characteristic (ROC) curves.ResultsA total of 4716 individuals were eligible for study. Each of the three scores was a statistically significant predictor of mortality. In this sample, the modified KTS significantly outperformed the ISS (AUC = 0.83, 95% CI 0.81–0.84 vs. 0.77, 95% CI 0.76–0.79, respectively) and demonstrated similar predictive ability compared to the NISS (AUC = 0.83, 95% CI 0.81–0.84 vs. 0.82, 95% CI 0.80–0.83, respectively).ConclusionsThe modified KTS may represent a useful tool for assessing trauma mortality risk in real time, as well as in administrative data where physiologic measures are available. Further research is warranted and these findings suggest that the collection of physiologic measures in large databases may improve outcome prediction.     

金纳米微粒的特性及在肿瘤学中的应用

金纳米粒子,直径1-100nm,是无机金属纳米微粒中最稳定的纳米粒子之一,具有独特的光学和物理性能,如良好的稳定性、小尺寸效应、表面效应、光学效应和良好的生物相容性等特点,已经被广泛应用于生物医学领域。本篇对金纳米粒子特性、制备及医学应用的最新研究进展进行综述,为以后研究工作提供参考。     

Impact of the COVID-19 pandemic on orthopedic trauma workload in a London level 1 trauma center: the “golden month”: The COVid Emergency Related Trauma and orthopaedics (COVERT) Collaborative

Background and purpose — The COVID-19 pandemic has been recognized as an unprecedented global health crisis. This is the first observational study to evaluate its impact on the orthopedic workload in a London level 1 trauma center (i.e., a major trauma center [MTC]) before (2019) and during (2020) the “golden month” post-COVID-19 lockdown.Patients and methods — We performed a longitudinal observational prevalence study of both acute orthopedic trauma referrals, operative and anesthetic casemix for the first “golden” month from March 17, 2020. We compared the data with the same period in 2019. Statistical analyses included median (median absolute deviation), risk and odds ratios, as well as Fisher’s exact test to calculate the statistical significance, set at p ≤ 0.05.Results — Acute trauma referrals in the post-COVID period were almost halved compared with 2019, with similar distribution between pediatric and adult patients, requiring a significant 19% more admissions (RR 1.3, OR 2.6, p = 0.003). Hip fractures and polytrauma cases accounted for an additional 11% of the modal number of injuries in 2020, but with 19% reduction in isolated limb injuries that were modal in 2019. Total operative cases fell by a third during the COVID-19 outbreak. There was a decrease of 14% (RR 0.85, OR 0.20, p = 0.006) in aerosol-generating anesthetic techniques used.Interpretation — The impact of the COVID-19 pandemic has led to a decline in the number of acute trauma referrals, admissions (but increased risk and odds ratio), operations, and aerosolizing anesthetic procedures since implementing social distancing and lockdown measures during the “golden month.”

The global impact of COVID-19The novel coronavirus SARS-COV-2 (COVID-19) was first reported in December 2019 with the first patient hospitalized in the city of Wuhan, China (Wu et al. 2020). By mid-March 2020 the outbreak affected over 190 countries with over 450,000 cases and over 20,000 deaths, thus being declared a pandemic and a global public health emergency by the World Health Organization (2020). On January 24, 2020 Europe reported its first case followed by a case in the United Kingdom (UK) 5 days later (Spiteri et al. 2020). Such a pandemic is an unprecedented event, and governments have had to enact firm social distancing and lockdown measures in an attempt to mitigate further viral transmission (Anderson et al. 2020) in order to reduce morbidity and mortality.British response to the pandemicThe English government responded by implementing social distancing measures on the March 16, 2020 in an attempt to reduce the rate of transmission and therefore the demands on the National Health Service (UK Government 2020a). This was followed a week later by more stringent measures, commonly referred to as a societal “lockdown” (UK Government 2020b). As of March 23, 2020, all members of the public were required to stay at home except for limited purposes and this ruling received Royal Assent by March 26 within the rest of the UK. Furthermore, all public gatherings of more than 2 people and non-essential businesses were suspended. In response to the NHS emergency declaration (National Health Service England 2020), the Royal College of Surgeons (2020) and the British Orthopaedic Association (2020) both issued statements and guidelines for delivering emergency trauma and orthopedic care during the COVID-19 outbreak. The phenomenon of a reduction in trauma burden due to such social distancing measures has been described by Stinner et al. (2020), as well as the potential impact of COVID-19 on operative capacity and pathways. There has been little to explore on how COVID-19 affects the etiology of trauma referral workloads and the operative casemix.We evaluated the impact of the COVID-19 pandemic at a central London level 1 trauma center, also known as a Major Trauma Centre (MTC), evaluating the trends of acute orthopedic trauma referral caseload and operative casemix before (2019) and during (2020) the COVID-19 lockdown (i.e., the “golden” month period starting from March 17).       

Assessment of the trauma evaluation and management (TEAM) module in Australia

AIM: To assess the immediate effect on trauma-related knowledge of the trauma evaluation and management (TEAM) program applied to medical students in Australia. METHODS: 73 final year medical students from Melbourne were randomly assigned to two experimental groups (E1 and E2 who completed the TEAM program after a 20 item MCQ pre-test on trauma resuscitation and a second MCQ exam after the TEAM program) and two control groups (C1 and C2 who completed the pre- and post-MCQ exams before completing the TEAM module). All 73 students completed an evaluation questionnaire. Paired and unpaired t-tests were used for within and between groups comparisons. RESULTS: Groups C1 and C2 had similar mean scores in pre- and post-tests ranging from 57.2 to 60.5%. Groups E1 and E2 had similar pre-test scores but increased their post-test scores (pre-test range 53.8-57.1% and post-test 68.8-77.4%, P < 0.05). On a scale of 1-5 with five being the highest, a score of four or greater was assigned by over 74% of the students that the objectives were met, over 80% that trauma knowledge was improved, 25-40% that clinical skills were improved with over 74% overall satisfaction. Over 75% assigned a score of four or greater suggesting the module be mandatory. CONCLUSIONS: After the TEAM program there was significant improvement in cognitive skills. The students strongly supported its introduction in the undergraduate curriculum.