In vitro evaluation of hypochlorous acid-silver nanoparticle waterline disinfectant for dental unit waterline disinfection

Tingting Yin¹ , Qiaowen Li² , Huan Sun³ , Jin Zheng⁴ , Yuanyuan Wang⁵ , Yi Luo6 and Li Wang^7*

Abstract

Background This work intended to assess the disinfection efficacy of hypochlorous acid (HA) and silver nanoparticles (AgNP) disinfectants in disinfecting the dental unit waterlines (DUWL) during comprehensive oral treatment and explore their potential applications in the oral medical environment. Methods: Firstly, AgNP solution was prepared and evaluated through X-ray diffraction (XRD), field emission transmission electron microscope (FE-TEM), and stability tests. Subsequently, 15 dental units were selected and randomly assigned to three groups, each receiving a different disinfection method. Specifically, one group (5 units) received HA disinfectant (HA group), one group (5 units) received AgNP disinfectant (AgNP group), and another group (5 units) received a combination of HA and AgNP disinfectant (HA+AgNP group). Bacterial counts before and after disinfection were compared and analyzed at four sites on the dental units: high-speed handpiece tubing, mouthwash, ultrasonic scaler, and three-way syringe.

Results The growth of biofilm on the waterlines was observed using scanning electron microscopy (SEM) and laser confocal microscopy (LCM). The results indicated that AgNP solution was successfully prepared and demonstrated excellent stability. There was no significant difference in the average weekly number of patients treated across the three groups (P>0.05). After disinfection, bacterial counts were significantly reduced in all groups. Compared to the HA and AgNP groups, the HA+AgNP group exhibited a markedly lower bacterial count, with statistical significance (P<0.05). The compliance rates observed during the first disinfection and two weeks post-disinfection were slightly lower in the HA and AgNP groups compared to the HA+AgNP group, although no significant statistical difference was found (P>0.05). SEM images revealed uneven biofilm plaques on the inner surface of the pipes prior to disinfection, embedded within a dense matrix, while the biofilm was visibly disrupted post-disinfection. LCM software analysis showed that, compared to the HA and AgNP groups, the HA+AgNP group had a significantly lower percentage of live bacteria on the biofilm post-disinfection (P<0.05).

Conclusion Compared to any single disinfectant regimen, the combined use of HA and AgNPs effectively inhibited bacterial growth and exerted a significant destructive effect on biofilms. Therefore, this combination is expected to be a viable option for disinfection of DUWL in the oral healthcare setting.

Clinical trial number Not applicable.

Keywords Dentistry, Therapeutics, Waterline disinfectant, Hypochlorous acid, Silver nanoparticles

Effectiveness of Hypochlorous Acid to Reduce the Biofilms on Titanium Alloy Surfaces in Vitro

Chun-Ju Chen ¹ , Chun-Cheng Chen ^2,3,* and Shinn-Jyh Ding ^1,2,3,*

¹Institute of Oral Science, Chung Shan Medical University, Taichung City 402, Taiwan; 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

²School of Dentistry, Chung Shan Medical University, Taichung City 402, Taiwan

³Department of Dentistry, Chung Shan Medical University Hospital, Taichung City 402, Taiwan

^*Correspondence: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (C.-C.C.); 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (S.-J.D.); Tel.: +886-6-2471-8668 (ext. 55255) (C.-C.C.); +886-6-2471-8668 (ext. 55529) (S.-J.D.)

Academic Editor: Ihtesham ur Rehman

Received: 13 April 2016; Accepted: 15 July 2016; Published: 19 July 2016

Abstract: Chemotherapeutic agents have been used as an adjunct to mechanical debridement for peri-implantitis treatment. The present in vitro study evaluated and compared the effectiveness of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) at eliminating Gram-negative (E. coli and P. gingivalis) and Gram-positive (E. faecalis and S. sanguinis) bacteria. The effect of irrigating volume and exposure time on the antimicrobial efficacy of HOCl was evaluated, and a durability analysis was completed. Live/dead staining, morphology observation, alamarBlue assay, and lipopolysaccharide (LPS) detection were examined on grit-blasted and biofilm-contaminated titanium alloy discs after treatment with the three chemotherapeutic agents. The results indicated that HOCl exhibited better antibacterial efficacy with increasing irrigating volumes. HOCl achieved greater antibacterial efficacy as treatment time was increased. A decrease in antimicrobial effectiveness was observed when HOCl was unsealed and left in contact with the air. All the irrigants showed antibacterial activity and killed the majority of bacteria on the titanium alloy surfaces of biofilm-contaminated implants. Moreover, HOCl significantly lowered the LPS concentration of P. gingivalis when compared with NaOCl and CHX. Thus, a HOCl antiseptic may be effective for cleaning biofilm-contaminated implant surfaces.

Keywords: dental implant; hypochlorite acid; antiseptics; antimicrobial activity

Hypochlorous Acid for Wound Healing in Diabetic Rats: Effect on MMP-9 and Histology

Dita Mutiara Irawan ¹ , Ronny Lesmana^2–4 , Edhyana Sahiratmadja 4

¹Graduate School of Master Program in Anti Aging and Aesthetic Medicine, Faculty of Medicine, Universitas Padjadjaran,Jatinangor, 45363, Indonesia;²Center of Excellence in Higher Education for Pharmaceutical Care Innovation, Universitas Padjadjaran, Jatinangor, 45363, Indonesia; ³Division of Biological Activity, Central Laboratory, Universitas Padjadjaran, Sumedang, 45363, Indonesia; ⁴Department of Biomedical Science, Faculty of Medicine, Universitas Padjadjaran, Sumedang, 45363, Indonesia

Correspondence: Dita Mutiara Irawan, Email 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

Background: People who suffered type 2 diabetes have impaired healing of wounds due to the large number of circulating inflammatory cells resulting from high blood sugar levels. The wound healing process involves various complex processes including

the degradation of extracellular matrix, a process characterized by an increase in matrix metalloproteinase-9 (MMP-9). Conventional management of diabetic wounds usually involves systemic blood sugar control and topical antimicrobial treatment, including hydrogen peroxide and povidone-iodine, which are known to be cytotoxic to the cells involved in the wound healing cascade. Finding a safe, non-toxic, and effecting wound cleansing still poses a challenge, and hypochlorous acid (HOCl) could act as a potential candidate.

Purpose: Unveiling an HOCl ion as an agent for diabetic wound management and MMP-9 as a marker for delayed diabetic wound

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Flow Diagram is used to find and select related, eligible literatures for the review. The authors used several databases such as Pro Quest, Scopus, Springer link and

Science Direct. In addition, and to expand the data, the database on Google Scholar was also opened. Then, the compiled data are analyzed to form results and discussions to the research question.

Results: Five eligible articles passed the inclusion criteria and reviewed for data synthesis. From 5 pieces of literature, it was found that the use of HOCl ions can be a good choice of topical agent in the management of diabetic wounds and decrease the activity of

MMP-9, which act as a marker for delayed healing of diabetic wounds.

Conclusion: Topical agent, in this case HOCl ion, shows good results and can be used as an option in the management of diabetic wounds and MMP-9 can be used as a predictive marker in the management of diabetic wounds.

Keywords: diabetic wound, HOCl ion, hypochlorite acid, MMP-9, wound healing

Antimicrobial Hypochlorous Wound Irrigation Solutions Demonstrate Lower Anti-biofilm Efficacy Against Bacterial Biofilm in a Complex in-vitro Human Plasma Biofilm Model (hpBIOM) Than Common Wound Antimicrobials

Julian-Dario Rembe¹*†, Lioba Huelsboemer^2†, Isabell Plattfaut², Manuela Besser² and Ewa K. Stuermer³

¹Department of Vascular and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany,²Chair for Translational Wound Research, Centre for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany, ³Department of Vascular Medicine, University Heart and Vascular Center Hamburg, Translational Wound Research, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany

Biofilms pose a relevant factor for wound healing impairment in chronic wounds.With 78% of all chronic wounds being affected by biofilms, research in this area is of high priority, especially since data for evidence-based selection of appropriate antimicrobials and antiseptics is scarce.Therefore,the objective of this study was to evaluate the anti-biofilm efficacy of commercially available hypochlorous wound irrigation solutions compared to established antimicrobials.Using an innovative complex in-vitro human plasma biofilm model(hpBIOM),quantitative reduction of Pseudomonas aeruginosa,Staphylococcus aureus,and Methicillin-resistant S. aureus (MRSA) biofilms by three hypochlorous irrigation solutions[two polyhexanide (PHMB)irrigation solution and 0.1%octenidine-dihydrochloride/phenoxyethanol(OCT/PE).Efficacy was compared to a non-challenged planktonic approach,as well as with increased substance volume over a prolonged exposure (up to 72 h).Qualitative visualization of biofilms was performed by scanning electron microscopy (SEM). Both reference agents(OCT/PE and PHMB)induced significant biofilm reductions within 72 h,whereby high volume OCT/PE even managed complete eradication of P. aeruginosa and MRSA biofilms after72 h.The tested hypochlorous wound irrigation solutions achieved no relevant penetration and eradication of biofilms despite increased volume and exposure. Only 0.2% NaClO managed a low reduction under prolonged exposure.The results demonstrate that low-dosed hypochlorous wound irrigation solutions are significantly less effective than PHMB-based irrigation solution and OCT/PE, thus unsuitable for biofilm eradication on their own. The used complex hpBIOM thereby mimics the highly challenging clinical wound microenvironment, providing a more profound base for future clinical translation.

Keywords: wound infection, biofilm, antimicrobial, antiseptic, hypochlorous acid, human plasma bioflm model, wound irrigation, chronic wound

Narrowing the chromosome 22q11.2 locus duplicated in bladder exstrophyeepispadias complex

Glenda M. Beaman ^a,b, Adrian S. Woolf ^c,d, Filipa M. Lopes ^c, Shuang Andrew Guo ^{e,f,g, J}. Robert Harkness ^a,b, Raimondo M. Cervellione ^d, David Keene ^d, Imran Mushtaq ^h, Menna R. Clatworthy ^f,g,h, William G. Newman ^a,b,*

Summary

Introduction

Bladder exstrophyeepispadias complex (BEEC) comprises a spectrum of anterior midline congenital malformations, involving the lower urinary tract. BEEC is usually sporadic, but families with more than one affected member have been reported, and a twin concordance study supported a genetic contribution to pathogenesis. Moreover, diverse chromosomal aberrations have been reported in a small subset of individuals with BEEC. The commonest are 22q11.2 microduplications, identified in approximately 3% of BEEC index cases.

Objectives

We aimed to refine the chromosome 22q11.2 locus, and to determine whether the encompassed genes are expressed in normal developing and mature human urinary bladders.

Results

Using DNA from an individual with CBE, the 22q11.2 duplicated locus was refined by identification of a maternally inherited 314 kb duplication (chr22:21,147,293e21,461,017), as depicted in this image. Moreover, the eight protein coding genes within the locus were found to be expressed during normal developing and mature bladders. To determine whether duplications in any of these individual genes were associated with CBE, we undertook copy number analyses in 115 individuals with CBE without duplications of the whole locus. No duplications of individual genes were found.

Discussion

The current study has refined the22q11.2locus associated with BEEC and has shown that the eight protein coding genes are expressed in human bladders both during antenatal development and postnatally. Nevertheless, the precise biological explanation as to why duplication of the phenocritical region of22q11 confers increased susceptibility to BEEC remains to be determined. The fact that individuals with CBE without duplications of the whole locus also lacked duplication of any of the individual genes suggests that in individuals with BEEC and duplication of the 22q11.2 locus altered dosage of more than one gene may be important in BEEC etiology.

Conclusions

The study has refined the 22q11.2 locus associated with BEEC and has shown that the eight protein coding genes within this locus are expressed in human bladders. 

W. Hardy Hendren, III, M.D., A personal perspective