New strategies for preoperative skin antisepsis

Easy to use particle-mediated transport of various dissolved active agents into the hair follicles - A novel platform technology

The use of nanoparticulate systems for the transport of active ingredients into hair follicles has been researched for almost two decades, resulting in countless publications with a wide variety of particle types, release mechanisms and active ingredients. The production of a stable dispersion is often time-consuming and costly. In this publication, we demonstrate for the first time that simply adding diverse submicron particles to a drug solution significantly increases follicular penetration depth by over 160% to 190%, allowing the targeting of subinfundibular structures. Our results indicate that the increase in follicular penetration is independent of the type or sphericity of the particles (nanocrystals (NC) or lipid submicron particles (LN)). Furthermore, this principle can be used with both small molecules and large molecule therapeutics, as demonstrated with the model drugs fluorescein sodium, 6-carboxyfluorescein, green fluorescent protein and FITC-BSA. This highlights the high versatility of this new formulation principle. The system may be used for various hair follicle-associated diseases such as alopecia or for the preoperative disinfection of hair follicles and the transfollicular transport of active pharmaceutical and/or cosmetic ingredients.

Study on hand disinfection in inpatient geriatric care on the superiority of cold plasma aerosol versus alcohol-based disinfection methods in a parallel group design

The introduction of fundamental hygiene protocols within the healthcare sector during the nineteenth century led to a significant reduction in mortality rates. Contemporary advancements, such as alcohol-based sanitizers, have further enhanced hand hygiene practices. However, these measures are often overlooked in nursing facilities, resulting in low staff compliance rates and increased cross-infection rates. Novel approaches, such as cold plasma hand disinfection, present promising alternatives due to their minimal skin damage and economic benefits. This study aims to compare the disinfectant efficacy of cold plasma aerosol under practical application conditions with an alcoholic hand disinfectant listed by the Association for Applied Hygiene. The microbial count on participants' hands was measured, with particular attention paid to the spontaneous occurrence of fecal indicators and the presence of potentially infectious bacteria. A t-test for independent samples was conducted to determine whether there was a significant difference between the two cohorts regarding the research question. Statistical analysis revealed that the mean log colony-forming unit (CFU) values were significantly lower in the test cohort using only the cold plasma method for hand disinfection compared to the cohort using conventional alcohol-based hand disinfection. Moreover, it was demonstrated that, unlike alcohol-based hand disinfection, cold plasma application ensures the effective elimination of Staphylococcus aureus. The findings indicate that staff utilizing plasma disinfection have an average bacterial count that is 0.65 log units lower than those who regularly use alcohol-based hand disinfection. In addition to the efficacy of cold plasma disinfection, its superiority over alcohol-based hand disinfection was also established. Beyond offering economic and logistical advantages, cold plasma disinfection provides additional health benefits as it does not induce skin damage, unlike alcohol-based hand disinfection.

Atmospheric pressure plasma treatment of skin: penetration into hair follicles

Sterilization of skin prior to surgery is challenged by the reservoir of bacteria that resides in hair follicles. Atmospheric pressure plasma jets (APPJs) have been proposed as a method to treat and deactivate these bacteria as atmospheric plasmas are able to penetrate into structures and crevices with dimensions similar to those found in hair follicles. In this paper, we discuss results from a computational investigation of an APPJ sustained in helium flowing into ambient air, and incident onto a layered dielectric similar to human skin in which there are idealized hair follicles. We found that, depending on the location of the follicle, the bulk ionization wave (IW) incident onto the skin, or the surface IW on the skin, are able to launch IWs into the follicle. The uniformity of treatment of the follicle depends on the location of the first entry of the plasma into the follicle on the top of the skin. Typically, only one side of the follicle is treated on for a given plasma pulse, with uniform treatment resulting from rastering the plasma jet across the follicle over many pulses. Plasma treatment of the follicle is sensitive to the angle of the follicle with respect to the skin, width of the follicle pocket, conductivity of the dermis and thickness of the underlying subcutaneous fat layer, the latter due to the change in capacitance of the tissue.

Advanced Skin Antisepsis: Application of UVA-Cleavable Hydroxyethyl Starch Nanocapsules for Improved Eradication of Hair Follicle-Associated Microorganisms

Hair follicles constitute important drug delivery targets for skin antisepsis since they contain ≈25% of the skin microbiome. Nanoparticles are known to penetrate deeply into hair follicles. By massaging the skin, the follicular penetration process is enhanced based on a ratchet effect. Subsequently, an intrafollicular drug release can be initiated by various trigger mechanisms. Here, we present novel ultraviolet A (UVA)-responsive nanocapsules (NCs) with a size between 400 and 600 nm containing hydroxyethyl starch (HES) functionalized by an o-nitrobenzyl linker. A phase transfer into phosphate-buffered saline (PBS) and ethanol was carried out, during which an aggregation of the particles was observed by means of dynamic light scattering (DLS). The highest stabilization for the target medium ethanol as well as UVA-dependent release of ethanol from the HES-NCs was achieved by adding 0.1% betaine monohydrate. Furthermore, sufficient cytocompatibility of the HES-NCs was demonstrated. On ex vivo porcine ear skin, a strong UVA-induced release of the model drug sulforhodamine 101 (SR101) could be demonstrated after application of the NCs in cyclohexane using laser scanning microscopy. In a final experiment, a microbial reduction comparable to that of an ethanol control was demonstrated on ex vivo porcine ear skin using a novel UVA-LED lamp for triggering the release of ethanol from HES-NCs. Our study provides first indications that an advanced skin antisepsis based on the eradication of intrafollicular microorganisms could be achieved by the topical application of UVA-responsive NCs.

Hygiene in der Dermatologie – Teil 2: Kommensalen und Infektionserreger, antimikrobielle Behandlung, Hygieneaspekte ausgewählter Infektionskrankheiten

In diesem Beitrag werden Kommensalen und relevante Infektionserreger des dermatologischen Patienten wie auch seiner Umgebung systematisch dargestellt und im Hinblick auf die krankenhaushygienische Bedeutung eingeordnet. Auf der antimikrobiellen Behandlung sowie Hygiene-Maßnahmen ausgewählter dermatologischer Erkrankungen liegt ein weiterer Fokus.

Release of the model drug SR101 from polyurethane nanocapsules in porcine hair follicles triggered by LED-derived low dose UVA light

Hair follicles (HFs) are important drug delivery targets for the therapy of miscellaneous skin diseases and for skin antisepsis. Furthermore, HFs significantly contribute to drug delivery of topically applied substances. Nanoparticulate systems are excellently suited for follicular drug delivery as they entail the opportunity of directed drug transport into HFs. Moreover, they involve the possibility of an intrafollicular drug release initiated by extrinsic or intrinsic trigger mechanisms. In this study, we present a novel preclinical model for an anatomically and temporally targeted intrafollicular drug release. In vitro release kinetics of the model drug sulforhodamine 101 (SR101) from newly synthesized ultraviolet A (UVA)-responsive polyurethane nanocapsules (NCs) were investigated by fluorescence spectroscopy. Low power density UVA radiation provided by a UVA light emitting diode (LED) induced a drug release of over 50% after 2 min. We further utilized confocal laser scanning microscopy (CLSM) to investigate follicular penetration as well as intrafollicular drug release on an ex vivo porcine ear skin model. UVA-responsive degradation of the NCs at a mean follicular penetration depth of 509 ± 104 µm ensured liberation of SR101 in the right place and at the right time. Thus, for the first time a UVA-triggered drug release from NCs within HFs was demonstrated in the present study. Cytotoxicity tests revealed that NCs synthesized with isophorone diisocyanate show sufficient biocompatibility after UVA-induced cleavage. A considerable and controllable release of various water-soluble therapeutics could be reached by means of the presented system without risking any radiation-related tissue damage. Therefore, the implementation of the presented system into clinical routine, e.g. for preoperative antisepsis of HFs, appears very promising.

Cutibacterium avidum resists surgical skin antisepsis in the groin-a potential risk factor for periprosthetic joint infection: a quality control study

BACKGROUND

The skin commensal Cutibacterium avidum has been recognized as an emerging pathogen for periprosthetic joint infections (PJI). One currently assumes that the early occurring PJIs are a consequence of skin commensals contaminating the peri-implant tissue during surgery. We addressed whether standard skin antisepsis with povidone-iodine/alcohol before total hip arthroplasty (THA) is effective to eliminate colonizing bacteria with focus on C. avidum.

METHODS

In a single-center, prospective study, we screened all patients for skin colonizing C. avidum in the groin before THA. Only in the patients positive for C. avidum, we preoperatively repeated skin swabs after the first and third skin antisepsis and antibiotic prophylaxis. We also obtained dermis biopsies for microbiology and fluorescence in situ hybridization (FISH).

RESULTS

Fifty-one out of 60 patients (85%) were colonized on the skin with various bacteria, in particular with C. avidum in 12 out of 60. Skin antisepsis eliminated C. avidum in eight of ten (20%) colonized patients undergoing THA. Deeper skin (dermis) biopsies were all culture negative, but FISH detected single positive ribosome-rich C. avidum in one case near sweat glands.

CONCLUSION

Standard skin antisepsis was not effective to completely eliminate colonizing C. avidum on the skin in the groin of patients undergoing THA. Colonizing with C. avidum might pose an increased risk for PJI when considering a THA. Novel more effective antisepsis strategies are needed. Trial registration No clinical trial.

Comparison of the antimicrobial efficacy of povidone-iodine-alcohol versus chlorhexidine-alcohol for surgical skin preparation on the aerobic and anaerobic skin flora of the shoulder region

Background

Cutibacterium acnes is part of the anaerobic skin microbiome and resides in deeper skin layers. The organism is an agent of surgical site infections (SSI) in shoulder surgery. We hypothesized that prolonged skin preparation with an agent that penetrates deeply into the skin would be beneficial. Thus, we compared two classes of antiseptics, each combined with alcohol, each applied with two different contact times.

Methods

Using a cross-over arrangement, shoulders of 16 healthy volunteers were treated for 2.5 min (standard) or 30 min (prolonged) with alcohol-based chlorhexidine (CHG-ALC) or alcohol-based povidone-iodine (PVP-I-ALC). Skin sites were sampled before, immediately after, and 3 h after treatment, using a standardized cup-scrub technique.

Results

Aerobic skin flora was reduced more effectively by PVP-I-ALC than by CHG-ALC after 2.5 min application and immediate sampling (reduction factor [RF] 2.55 ± 0.75 vs. 1.94 ± 0.91, p = 0.04), but not after prolonged contact times and 3-h sampling. Coagulase-negative staphylococci were completely eliminated after PVP-I-ALC application, but still recovered from 4 of 32 samples after CHG-ALC application. Anaerobic flora was reduced more effectively by PVP-I-ALC than CHG-ALC after standard (RF 3.96 ± 1.46 vs. 1.74 ± 1.24, p < 0.01) and prolonged (RF 3.14 ± 1.20 vs. 1.38 ± 1.16, p < 0.01) contact times and immediate sampling, but not after 3-h sampling. No adverse events were reported.

Conclusions

PVP-I-ALC showed marginal benefits concerning the aerobic flora, but more substantial benefits over CHG-ALC concerning the anaerobic flora of the shoulder. Standard and prolonged contact times showed superiority for PVP-I-ALC for anaerobic flora at all immediate sampling points, but missed significance at 3-h sampling. The results underscore the need for protection against C. acnes and coagulase-negative staphylococci in orthopaedic surgery. The clinical relevance of these findings, however, should be studied with SSI as an endpoint.

Chemical disinfection in healthcare settings: critical aspects for the development of global strategies

Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.

Revisiting Perioperative Hair Removal Practices

The standard of practice for perioperative hair removal is largely based on research that is outdated and underpowered. Although there is evidence to support the practice of clipping instead of shaving, current recommendations are to remove hair only when absolutely necessary. Human hair is bacteria-laden and challenging to disinfect, and clipping can be a safe method of hair removal that does not damage the skin. This article considers the removal of hair at the incision site with clippers, either before the patient enters the OR or in a manner that completely contains clipped hair, for every procedure, not just when absolutely necessary. There have been only two studies to date comparing clipping with no hair removal; more research is needed on this subject.

Laser scanning microscopy for control of skin decontamination efficacy from airborne particulates using highly absorbent textile nanofiber material in combination with PEG-12 dimethicone

BACKGROUND

The decontamination of the skin is indispensable if airborne particulate contaminants deposit on the skin surface. Skin washing can have adverse effects as by skin rubbing the particles can be transferred deeply into the hair follicles, where they can be entrapped for a period of more than 10 days. Thus, alternative skin decontamination strategies are necessary.

MATERIALS AND METHODS

For imaging the contaminants in the skin, sodium fluorescein-labeled soot particles of submicron size (≈600 nm) were visualized using laser scanning microscopy.

RESULTS

In the present ex vivo pilot study on porcine ear skin, it was shown that sodium fluorescein-labeled soot particles of submicron size (≈600 nm) could be efficiently removed from the skin with highly absorbent textile nanofiber material, whose efficacy could be further increased by spraying the contaminated skin area with the viscous fluid PEG-12 dimethicone before textile application.

CONCLUSION

In case of skin contamination with particulates, the contact washing should be avoided due to rubbing particles deeply into the hair follicles, where they can accumulate for a long time and induce negative consequences. Efficient skin decontamination could include pretreatment of skin surface with the viscous fluid PEG-12 dimethicone and subsequent application of highly absorbent textile nanofiber material.

Air quality in the operating room: Surgical site infections, HVAC systems and discipline - position paper of the German Society of Hospital Hygiene (DGKH)

In recent years, there has been an ongoing discussion about the value of laminar airflow (LAF=low turbulence displacement ventilation) in the operating room for prevention of surgical site infections (SSI). Some publications, e.g., from the WHO, issued the demand to no longer build LAF ceilings in operating rooms. The present statement deals critically with this position and justifies the use of LAF ceilings in different ways: Many of the papers cited by the WHO and others for the case against LAF do not provide reliable data.The remaining studies which might be used for answering the question give quite different results, also in favor of LAF.The size of the LAF ceiling in many studies is not given or mostly too small in comparison to actual technical requirements.LAF in different countries can mean quite different techniques (e.g., the US in comparison to Germany) so that the results of studies that do not take this into account may not be comparable.LAF has positive effects in terms of reducing particulate and bacterial load, associated with increased airflow in the surgical working area. A reduction of carcinogenic substances in the air may also be assumed, which would increase workers' safety. Thus, this paper recommends building LAF ceilings in the future as well, depending on the operations intended. Further, this paper gives an overview of possible reasons for surgical site infections and highlights the importance of discipline in the operating theatre.

Fundamental Basis of Scalp Layering Techniques to Protect Against Wound Infection: A Comparative Study Between Conventional and In-to-Out Dissection of the Superficial Temporal Artery

BACKGROUND

Superficial temporal artery (STA) to middle cerebral artery (MCA) bypass is associated with several surgical problems. Despite the vascular patency and hemodynamic changes after the anastomosis, wound problems can be a major surgical complication.

METHODS

In a review of 41 surgical cases of STA-MCA bypass for moyamoya disease or cerebral occlusive vascular disease, we compared the conventional (out-to-in) dissection method for STA (n = 23) with the in-to-out (ITO) dissection method (n = 18) and evaluated the surgical results with respect to wound problems.

RESULTS

The incidence of skin maceration was significantly higher in the conventional dissection group than the ITO dissection group (34.8% vs. 5.5%; P < 0.01). Skin necrosis also showed a higher incidence in the conventional dissection group (39.1%) than the ITO group (22.2%).

CONCLUSIONS

These data suggest that the simple layering technique of the ITO dissection method can protect against contamination from bacteria and reduce postoperative surgical wound problems. Sealing of the galea aponeurotica (first protective barrier), including fibrous septa and loose areolar tissues, including the periosteal layer (second protective barrier), is an important factor to decrease the rate of scalp wound infection.

Antimicrobial efficacy of preoperative skin antisepsis and clonal relationship to postantiseptic skin-and-wound flora in patients undergoing clean orthopedic surgery

Nosocomial surgical site infections (SSI) are still important complications in surgery. The underlying mechanisms are not fully understood. The aim of this study was to elucidate the possible role of skin flora surviving preoperative antisepsis as a possible cause of SSI. We conducted a two-phase prospective clinical trial in patients undergoing clean orthopedic surgery at a university trauma center in northern Germany. Quantitative swab samples were taken from pre- and postantiseptic skin and, additionally, from the wound base, wound margin, and the suture of 137 patients. Seventy-four patients during phase I and 63 during phase II were investigated. Microbial growth, species spectrum, and antibiotic susceptibility were analyzed. In phase two, the clonal relationship of strains was additionally analyzed. 18.0 % of the swab samples were positive for bacterial growth in the wound base, 24.5 % in the margin, and 27.3 % in the suture. Only 65.5 % of patients showed a 100 % reduction of the skin flora after antisepsis. The microbial spectrum in all postantiseptic samples was dominated by coagulase-negative staphylococci (CoNS). Clonally related staphylococci were detected in ten patients [nine CoNS, one methicillin-susceptible Staphylococcus aureus (MSSA)]. Six of ten patients were suspected of having transmitted identical clones from skin flora into the wound. Ethanol-based antisepsis results in unexpected high levels of skin flora, which can be transmitted into the wound during surgery causing yet unexplained SSI. Keeping with the concept of zero tolerance, further studies are needed in order to understand the origin of this flora to allow further reduction of SSI.

Skin and wound decontamination of multidrug-resistant bacteria by cold atmospheric plasma coagulation

BACKGROUND AND OBJECTIVES

Novel concepts to limit the spread of multidrug-resistant bacteria (MDR) are urgently needed. Since treatment with cold atmospheric plasma (CAP) has shown significant antibacterial properties, the purpose of this study was to evaluate the ability of CAP to eliminate MDR- compared to non-MDR-pathogens in chronic wounds.

METHODS

Eleven patients with 18 heavily colonized wounds were treated with a CE-certified commercial argon-based CAP source for 10 s/cm(2) in one session. The antimicrobial efficacy was assessed by calculating the microbial load before and after treatment.

RESULTS

A single CAP treatment reduced MDR in all wounds. In 14 treatments (63.6 %) and for 16 pathogens (66.7 %), a 100 % reduction of the bacterial load was observed. For 11 of 17 (64.7 %) MDR-pathogens and for 5 of 7 (71.4 %) other non-MDR-pathogens, complete eradication was achieved. The remaining 8 treatments showed reductions of 77.5 ± 18.6 % and the remaining pathogens a reduction of 74.8 ± 25.7 %.

CONCLUSIONS

As proof of principle, argon-based CAP serves as a potent treatment modality that was shown to limit MDR microbial colonization. The possible role of CAP in clinical MDR decontamination must be evaluated in clinical trials with repeated plasma treatment embedded in a comprehensive hygienic decontamination concept.

Fighting surgical site infections in small animals: are we getting anywhere?

A diverse array of pathogen-related, patient-related, and caretaker-related issues influence risk and prevention of surgical site infections (SSIs). The entire surgical team involved in health care settings in which surgical procedures are performed play a pivotal role in the prevention of SSIs. In this article, current knowledge of SSI risk factors and prevention methods is reviewed. Although new avenues that can be explored in the prevention of SSIs in veterinary medicine are described, the main conclusion drawn is that the best method for prevention of SSI is to adhere to what we already know.