Povidone iodine in wound healing: A review of current concepts and practices

Chorioallantoic Membrane Assay as Model for Angiogenesis in Tissue Engineering: Focus on Stem Cells

Tissue engineering aims to structurally and functionally regenerate damaged tissues, which requires the formation of new blood vessels that supply oxygen and nutrients by the process of angiogenesis. Stem cells are a promising tool in regenerative medicine due to their combined differentiation and paracrine angiogenic capacities. The study of their proangiogenic properties and associated potential for tissue regeneration requires complex in vivo models comprising all steps of the angiogenic process. The highly vascularized extraembryonic chorioallantoic membrane (CAM) of fertilized chicken eggs offers a simple, easy accessible, and cheap angiogenic screening tool compared to other animal models. Although the CAM assay was initially primarily performed for evaluation of tumor growth and metastasis, stem cell studies using this model are increasing. In this review, a detailed summary of angiogenic observations of different mesenchymal, cardiac, and endothelial stem cell types and derivatives in the CAM model is presented. Moreover, we focus on the variation in experimental setup, including the benefits and limitations of in ovo and ex ovo protocols, diverse biological and synthetic scaffolds, imaging techniques, and outcome measures of neovascularization. Finally, advantages and disadvantages of the CAM assay as a model for angiogenesis in tissue engineering in comparison with alternative in vivo animal models are described. Impact statement The chorioallantoic membrane (CAM) assay is an easy and cheap screening tool for the angiogenic properties of stem cells and their associated potential in the tissue engineering field. This review offers an overview of all published angiogenic studies of stem cells using this model, with emphasis on the variation in used experimental timeline, culture protocol (in ovo vs. ex ovo), stem cell type (derivatives), scaffolds, and outcome measures of vascularization. The purpose of this overview is to aid tissue engineering researchers to determine the ideal CAM experimental setup based on their specific study goals.

"Smart" Antimicrobial Nanocomplexes with Potential to Decrease Surgical Site Infections (SSI)

The emergence of resistant pathogens is a burden on mankind and threatens the existence of our species. Natural and plant-derived antimicrobial agents need to be developed in the race against antibiotic resistance. Nanotechnology is a promising approach with a variety of products. Biosynthesized silver nanoparticles (AgNP) have good antimicrobial activity. We prepared AgNPs with trans-cinnamic acid (TCA) and povidone-iodine (PI) with increased antimicrobial activity. We synthesized also AgNPs with natural cinnamon bark extract (Cinn) in combination with PI and coated biodegradable Polyglycolic Acid (PGA) sutures with the new materials separately. These compounds (TCA-AgNP, TCA-AgNP-PI, Cinn-AgNP, and Cinn-AgNP-PI) and their dip-coated PGA sutures were tested against 10 reference strains of microorganisms and five antibiotics by zone inhibition with disc- and agar-well-diffusion methods. The new compounds TCA-AgNP-PI and Cinn-AgNP-PI are broad spectrum microbicidal agents and therefore potential coating materials for sutures to prevent Surgical Site Infections (SSI). TCA-AgNP-PI inhibits the studied pathogens stronger than Cinn-AgNP-PI in-vitro and on coated sutures. Dynamic light scattering (DLS), ultraviolet-visible spectroscopy (UV-Vis), Fourier Transform infrared spectroscopy (FT-IR), Raman, x-ray diffraction (XRD), microstructural analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) confirmed the composition of TCA-AgNP-PI and Cinn-AgNP-PI. Smart solutions involving hybrid materials based on synergistic antimicrobial action have promising future perspectives to combat resistant microorganisms.

Effective Hand Preparation for Surgical Procedures in Low- and Middle-Income Countries

Background: The burden of healthcare-associated infections (HAIs) is greatest in low- and middle-income countries (LMICs); surgical site infections (SSIs) are the most common HAI in LMICs. Hand hygiene is the single most effective strategy for reducing HAIs and the transmission of antimicrobial drug-resistant pathogens. Similarly, effective surgical hand preparation is a critical step in the prevention of SSIs in the surgical patient. Methods: Surgical hand preparation (SHP) is a seemingly simple activity that is easily overlooked. Performed properly, however, along with other measures, it has the potential to reduce SSIs in LMICs. The article reviews the current state of surgical hand preparation in LMICs. Results: Alcohol-based handrubs (ABHRs) have received wide acceptance by healthcare workers for both hand hygiene and SHP; when mixed with emollients, ABHRs retain efficacy against microorganisms and gain skin tolerability and user acceptability. Healthcare institutions in many LMICs face difficulties obtaining the products needed to ensure effective SHP using ABHRs. Conclusion: The ABHRs are the most efficacious surgical hand preparation products available today. They are cost-effective and can safely be prepared locally in hospitals, even in LMICs. The challenge of access to ABHRs should be addressed by national and local governments, through advocacy by healthcare workers coupled with continued lobbying and campaigns by the World Health Organization. Effective surgical hand preparation, like hand hygiene, saves lives.

Management of Adenoviral Keratoconjunctivitis: Challenges and Solutions

Human adenovirus (HAdV) is the most common cause of infectious conjunctivitis, accounting for up to 75% of all conjunctivitis cases and affecting people of all ages and demographics. In addition to ocular complications, it can cause systemic infections in the form of gastroenteritis, respiratory disease, and dissemination in immunocompromised individuals. HAdV causes lytic infection of the mucoepithelial cells of the conjunctiva and cornea, as well as latent infection of lymphoid and adenoid cells. Epidemic keratoconjunctivitis (EKC) is the most severe ocular manifestation of HAdV infection, in which the presence of subepithelial infiltrates (SEIs) in the cornea is a hallmark feature of corneal involvement. SEIs have the tendency to recur and may lead to long-term visual disability. HAdV persistence and dissemination are linked to sporadic outbreaks of adenoviral keratoconjunctivitis. There is no FDA-approved antiviral for treating adenoviral keratoconjunctivitis, and as such, solutions should be proffered to handle the challenges associated with viral persistence and dissemination. Several treatment modalities have been investigated, both systemically and locally, to not only mitigate symptoms but reduce the course of the infection and prevent the risk of long-term complications. These options include systemic and topical antivirals, in-office povidone-iodine irrigation (PVI), immunoglobulin-based therapy, anti-inflammatory therapy, and immunotherapy. More recently, combination PVI/dexamethasone ophthalmic formulations have shown favorable outcomes and were well tolerated in clinical trials for the treatment of EKC. Possible, future treatment considerations include sialic acid analogs, cold atmospheric plasma, N-chlorotaurine, and benzalkonium chloride. Continued investigation and evaluation of treatment are warranted to reduce the economic burden and potential long-term visual debilitation in affected patients. This review will focus on how persistence and dissemination of HAdV pose a significant challenge to the management of adenoviral keratoconjunctivitis. Furthermore, current and future trends in prophylactic and therapeutic modalities for adenoviral keratoconjunctivitis will be discussed.

Bacteriophages for Chronic Wound Treatment: from Traditional to Novel Delivery Systems

The treatment and management of chronic wounds presents a massive financial burden for global health care systems, with significant and disturbing consequences for the patients affected. These wounds remain challenging to treat, reduce the patients' life quality, and are responsible for a high percentage of limb amputations and many premature deaths. The presence of bacterial biofilms hampers chronic wound therapy due to the high tolerance of biofilm cells to many first- and second-line antibiotics. Due to the appearance of antibiotic-resistant and multidrug-resistant pathogens in these types of wounds, the research for alternative and complementary therapeutic approaches has increased. Bacteriophage (phage) therapy, discovered in the early 1900s, has been revived in the last few decades due to its antibacterial efficacy against antibiotic-resistant clinical isolates. Its use in the treatment of non-healing wounds has shown promising outcomes. In this review, we focus on the societal problems of chronic wounds, describe both the history and ongoing clinical trials of chronic wound-related treatments, and also outline experiments carried out for efficacy evaluation with different phage-host systems using in vitro, ex vivo, and in vivo animal models. We also describe the modern and most recent delivery systems developed for the incorporation of phages for species-targeted antibacterial control while protecting them upon exposure to harsh conditions, increasing the shelf life and facilitating storage of phage-based products. In this review, we also highlight the advances in phage therapy regulation.

Acute wound infections management: the 'Don'ts' from a multidisciplinary expert panel

Introduction: The management of acute wounds may be affected by malpractices leading to poor outcome, prolonged hospital stay and inappropriate use of antibiotic therapy.Areas covered: Acute wound infections are represented by surgical site and post-traumatic infections. The aim of this expert opinion is to identify a list of inadvisable actions and to provide a guide for an optimal management of acute wound infections. A literature search using Pubmed/MEDLINE database was performed. Articles pertaining to areas covered published until December 2019 were selected. We identified the most common malpractices in this setting and, using the Choosing Wisely methodology, we proposed a list of "Don'ts" for an easy use in clinical practice.Expert opinion: Malpractices may occur from the surgical prophylaxis to the discharge of patient. A prolonged surgical prophylaxis, the underestimation of signs and symptoms, the omission of source control, the inappropriate collection of wound swab, the improper use of clinical microbiology and pharmacology, the lack of hygiene measures and the delay of discharge are all factors that may lead to unfavorable outcome. A multidisciplinary approach is needed to optimally manage these patients. The "Don'ts" refer to all professional figures involved in the management of patients with acute wound infections.

Dilute Betadine Lavage Reduces the Risk of Acute Postoperative Periprosthetic Joint Infection in Aseptic Revision Total Knee and Hip Arthroplasty: A Randomized Controlled Trial

BACKGROUND

The purpose of this randomized, controlled trial is to determine whether dilute betadine lavage compared to normal saline lavage reduces the rate of acute postoperative periprosthetic joint infection (PJI) in aseptic revision total knee (TKA) and hip arthroplasty (THA).

METHODS

A total of 478 patients undergoing aseptic revision TKA and THA were randomized to receive a 3-minute dilute betadine lavage (0.35%) or normal saline lavage before surgical wound closure. Fifteen patients were excluded following randomization (3.1%) and six were lost to follow-up (1.3%), leaving 457 patients available for study. Of them, 234 patients (153 knees, 81 hips) received normal saline lavage and 223 (144 knees, 79 hips) received dilute betadine lavage. The primary outcome was PJI within 90 days of surgery with a secondary assessment of 90-day wound complications. A priori power analysis determined that 285 patients per group were needed to detect a reduction in the rate of PJI from 5% to 1% with 80% power and alpha of 0.05.

RESULTS

There were eight infections in the saline group and 1 in the betadine group (3.4% vs 0.4%, P = .038). There was no difference in wound complications between groups (1.3% vs 0%, P = .248). There were no differences in any baseline demographics or type of revision procedure between groups, suggesting appropriate randomization.

CONCLUSION

Dilute betadine lavage before surgical wound closure in aseptic revision TKA and THA appears to be a simple, safe, and effective measure to reduce the risk of acute postoperative PJI.

LEVEL OF EVIDENCE

Level I.

Antibiotic Delivery Strategies to Treat Skin Infections When Innate Antimicrobial Defense Fails

The epidermal skin barrier protects the body from a host of daily challenges, providing protection against mechanical insults and the absorption of chemicals and xenobiotics. In addition to the physical barrier, the epidermis also presents an innate defense against microbial overgrowth. This is achieved through the presence of a diverse collection of microorganisms on the skin (the "microbiota") that maintain a delicate balance with the host and play a significant role in overall human health. When the skin is wounded, the local tissue with a compromised barrier can become colonized and ultimately infected if bacterial growth overcomes the host response. Wound infections present an immense burden in healthcare costs and decreased quality of life for patients, and treatment becomes increasingly important because of the negative impact that infection has on slowing the rate of wound healing. In this review, we discuss specific challenges of treating wound infections and the advances in drug delivery platforms and formulations that are under development to improve topical delivery of antimicrobial treatments.

Evaluation and Management of Sports-Related Lacerations of the Head and Neck

Soft tissue injuries to the head and neck are a common occurrence in sports. These anatomical regions are somewhat predisposed because of the "athletic stance" that is utilized in many close-contact sports. Although appropriate use of protective equipment, including mouth guards, helmets, and face shields, has reduced the incidence and severity of these injuries, they still occur regularly. To provide appropriate medical care, one must possess adequate knowledge of the superficial and deep anatomical structures, fundamental knowledge and skill in regard to wound care, and awareness of potential poor outcomes related to lacerations of unique structures, such as the mouth, eye, or ear.

Prophylaxis measures for postinjection endophthalmitis

Intravitreal injections have become the most commonly performed ophthalmic procedure, transforming modern retina practice. Postinjection endophthalmitis, while rare, remains the most feared potential complication. Prophylaxis measures including topical antisepsis, hand hygiene, gloves, masks, and drapes have all been proposed to help prevent postinjection endophthalmitis; however, there remains significant variation in protocol, given the lack of agreement among retina specialists on which steps are crucial to prevent endophthalmitis. With millions of injections performed annually, collating data have helped us better understand risk factors for endophthalmitis after intravitreal injection. We summarize the consensus guidelines for intravitreal injection technique and comprehensively review the literature on prevention of postinjection endophthalmitis.

Dilute Povidone-Iodine Solution Prevents Intraoperative Contamination of Sterile Water Basins During Total Joint Arthroplasty

BACKGROUND

Periprosthetic joint infection is a major complication of total joint arthroplasty (TJA). The intraoperative splash basin has been found to be a potential source of contamination. Although consensus recommendations against the use of splash basin have been made, splash basin use continues to be taught and utilized in practice. This study aims to investigate the effect of dilute betadine addition to the sterile water (SW) contents (0.02% solution) of the splash basin on contamination rates. This intervention could preserve the functionality and preferential use of the splash basin. The primary outcome of this study is the rate of splash basin contamination, with secondary outcomes of prevalence of culture speciation and mean operative times association with the rate of positive cultures.

METHODS

Patients undergoing primary TJA were enrolled in a randomized controlled trial with assignment to either the intervention/betadine group, in which dilute betadine was added to the standard SW splash basin, or the control/standard SW group. For a total cohort of 104 patients, a 120 mL aliquot sample of basin fluid was collected at incision ("preprocedure") and closure ("postprocedure"). Samples were cultured and monitored for 48 hours for growth, with further testing as necessary to identify microbial speciation.

RESULTS

Of the final 100 postprocedure samples, 0 (0.0%) were positive in the betadine group, while there were 23 (47.9%) positive samples in the SW group (P < .001). Of the positive cultures, the most common species grown were coagulase-negative Staphylococcus, Corynebacterium, and Micrococcus. The mean operative time was an average of 11 minutes longer for cases with positive cultures.

CONCLUSION

In conclusion, treating SW splash basins with dilute povidone-iodine (0.02% solution) eliminates intraoperative contamination of splash basins in TJA procedures. This intervention is simple, low cost, and readily implementable, making it a reasonable addition to TJA protocols.

LEVEL OF EVIDENCE

Level 1, Controlled Laboratory Study.

Infectious Disease Management and Control with Povidone Iodine

With reports of vancomycin-resistant enterococci recently emerging in hospital settings, renewed focus is turning to the importance of multifaceted infection prevention efforts. Careful compliance with established hygiene practices by healthcare workers together with effective antiseptic options is essential for the protection of patients from infectious agents. For over 60 years, povidone iodine (PVP-I) formulations have been shown to limit the impact and spread of infectious diseases with potent antiviral, antibacterial and antifungal effects. In addition to a lack of reported resistance, the benefits of PVP-I include an excellent safety profile and a broad spectrum of effect due to its multimodal action. Studies have shown that hand washing with PVP-I-based antiseptics is effective for the decontamination of skin, while PVP-I mouthwashes and gargles significantly reduce viral load in the oral cavity and the oropharynx. The importance of PVP-I has been emphasised by its inclusion in the World Health Organization's list of essential medicines, and high potency for virucidal activity has been observed against viruses of significant global concern, including hepatitis A and influenza, as well as the Middle-East Respiratory Syndrome and Sudden Acute Respiratory Syndrome coronaviruses. Together with its diverse applications in antimicrobial control, broad accessibility across the globe, and outstanding safety and tolerability profile, PVP-I offers an affordable, potent, and widely available antiseptic option.Funding Mundipharma Singapore Holding Pte Limited.

Laser-induced vapor nanobubbles improve diffusion in biofilms of antimicrobial agents for wound care

Being responsible for delayed wound healing, the presence of biofilms in infected wounds leads to chronic, and difficult to treat infections. One of the reasons why antimicrobial treatment often fails to cure biofilm infections is the reduced penetration rate of antibiotics through dense biofilms. Strategies that have the ability to somehow interfere with the integrity of biofilms and allowing a better penetration of drugs are highly sought after. A promising new approach is the use of laser-induced vapor nanobubbles (VNB), of which it was recently demonstrated that it can substantially enhance the penetration of antibiotics into biofilms, resulting in a marked improvement of the killing efficiency. In this study, we examined if treatment of biofilms with laser-induced vapor nanobubbles (VNB) can enhance the potency of antimicrobials which are commonly used to treat wound infections, including povidone-iodine, chlorhexidine, benzalkonium chloride, cetrimonium bromide and mupirocin. Our investigations were performed on Pseudomonas aeruginosa and Staphylococcus aureus biofilms, which are often implicated in chronic wound infections. Pre-treatment of biofilms with laser-induced VNB did enhance the killing efficiency of those antimicrobials which experience a diffusion barrier in the biofilms, while this was not the case for those compounds for which there is no diffusion barrier. The magnitude of the enhanced potency was in most cases similar to the enhancement that was obtained when the biofilms were completely disrupted by vortexing and sonication. These results show that laser-induced VNB are indeed a very efficient way to enhance drug penetration deep into biofilms, and pave the way towards clinical translation of this novel approach for treatment of wound infections.

Enhanced Clearing of Wound-Related Pathogenic Bacterial Biofilms Using Protease-Functionalized Antibiotic Nanocarriers

Biofilms are prevalent in chronic wounds and once formed are very hard to remove, which is associated with poor outcomes and high mortality rates. Biofilms are comprised of surface-attached bacteria embedded in an extracellular polymeric substance (EPS) matrix, which confers increased antibiotic resistance and host immune evasion. Therefore, disruption of this matrix is essential to tackle the biofilm-embedded bacteria. Here, we propose a novel nanotechnology to do this, based on protease-functionalized nanogel carriers of antibiotics. Such active antibiotic nanocarriers, surface coated with the protease Alcalase 2.4 L FG, "digest" their way through the biofilm EPS matrix, reach the buried bacteria, and deliver a high dose of antibiotic directly on their cell walls, which overwhelms their defenses. We demonstrated their effectiveness against six wound biofilm-forming bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Klebsiella pneumoniae, Escherichia coli, and Enterococcus faecalis. We confirmed a 6-fold decrease in the biofilm mass and a substantial reduction in bacterial cell density using fluorescence, atomic force, and scanning electron microscopy. Additionally, we showed that co-treatments of ciprofloxacin and Alcalase-coated Carbopol nanogels led to a 3-log reduction in viable biofilm-forming cells when compared to ciprofloxacin treatments alone. Encapsulating an equivalent concentration of ciprofloxacin into the Alcalase-coated nanogel particles boosted their antibacterial effect much further, reducing the bacterial cell viability to below detectable amounts after 6 h of treatment. The Alcalase-coated nanogel particles were noncytotoxic to human adult keratinocyte cells (HaCaT), inducing a very low apoptotic response in these cells. Overall, we demonstrated that the Alcalase-coated nanogels loaded with a cationic antibiotic elicit very strong biofilm-clearing effects against wound-associated biofilm-forming pathogenic bacteria. This nanotechnology approach has the potential to become a very powerful treatment of chronically infected wounds with biofilm-forming bacteria.

Efficacy of a povidone-iodine foam dressing (Betafoam) on diabetic foot ulcer

This study aimed to assess the efficacy of a new povidone-iodine (PVP-I) foam dressing (Betafoam) vs foam dressing (Medifoam) for the management of diabetic foot ulcers. This study was conducted between March 2016 and September 2017 at 10 sites in Korea. A total of 71 patients (aged ≥19 years) with type 1/2 diabetes and early-phase diabetic foot ulcers (Wagener classification grade 1/2) were randomised to treatment with PVP-I foam dressing or foam dressing for 8 weeks. Wound healing, wound infection, patient satisfaction, and adverse events (AEs) were assessed. The PVP-I foam and foam dressing groups were comparable in the proportion of patients with complete wound healing within 8 weeks (44.4% vs 42.3%, P = .9191), mean (±SD) number of days to complete healing (31.00 ± 15.07 vs 33.27 ± 12.60 days; P = .6541), and infection rates (11.1% vs 11.4%; P = 1.0000). Median satisfaction score (scored from 0 to 10) at the final visit was also comparable between groups (10 vs 9, P = .2889). There was no significant difference in AE incidence (27.8% vs 17.1%, P = .2836), and none of the reported AEs had a causal relationship with the dressings. The results of this study suggest that PVP-I foam dressing has wound-healing efficacy comparable with foam dressing, with no notable safety concerns. This study was funded by Mundipharma Korea Ltd and registered at ClinicalTrials.gov (identifier NCT02732886).

Implant Surface Options and Biofilm Mitigation Strategies

Two important topics in breast augmentation and reconstruction relate to device surface texture and practices to mitigate biofilm contamination of implants. Breast augmentation can be considered a manufacturing process where planning concepts of process engineering and quality can be used to produce great outcomes. This article reviews the options available for surgeons with regards to device surface texture selection and practices to mitigate biofilm contamination of implants at the time of surgery.

The efficacy of diluted topical povidone-iodine rinses in the management of recalcitrant chronic rhinosinusitis: a prospective cohort study

PURPOSE

Recalcitrant chronic rhinosinusitis is a persistent inflammatory condition of the sinonasal mucosa despite adequate medical therapy and sinus surgery. This study aimed to demonstrate the effectiveness and safety of dilute povidone-iodine (PVP-I) sinonasal rinses as an adjunctive therapy.

METHODS

Prospective cohort study. Twenty-nine recalcitrant CRS patients with endoscopic evidence of ongoing inflammation and purulent discharge were prescribed 0.08% diluted PVP-I rinses. Changes to endoscopic modified Lund-Kennedy (MLK) scores at 7 weeks post-PVP-I rinsing served as the primary outcome measure.

RESULTS

The median MLK-discharge score significantly decreased in all patients by 1.50 points post-PVP-I rinsing (p value < 0.01). The total MLK score significantly decreased in all patients by 1.50 points (p value = 0.01). Up to a 17% reduction in serum inflammatory markers was measured post-PVP-I rinsing. Sinonasal culture revealed a shift from moderate-heavy growth to lighter bacterial growth overall. Subjective SNOT-22 scores significantly improved overall by ≥ 1 minimal clinically important difference (MCID > 12; baseline median = 33; follow-up median = 20; p value < 0.01; n = 22). TSH levels increased non-significantly within normal ranges (baseline median = 1.59 mU/L; follow-up median = 1.92 mU/L; p = 0.10; n = 15). Mucociliary clearance time increased non-significantly within normal ranges (baseline median = 9 min; follow-up median = 10 min; p value = 0.53; n = 17). Olfactory Sniffin'16 scores non-significantly decreased within age-related normal ranges (baseline median = 14; follow-up median = 13; p value = 0.72; n = 18).

CONCLUSION

A dilute 0.08% PVP-I sinonasal rinse as an ancillary therapy in recalcitrant CRS significantly reduces signs of infection alongside notable symptom improvement, without affecting thyroid function, mucociliary clearance or olfaction.

Antimicrobial and antibiofilm effects of abietic acid on cariogenic Streptococcus mutans

Dental caries is a type of oral microbiome dysbiosis and biofilm infection that affects oral and systemic conditions. For healthy life expectancy, natural bacteriostatic products are ideal for daily and lifetime use as anti-oral infection agents. This study aimed to evaluate the inhibitory effects of abietic acid, a diterpene derived from pine rosin, on the in vitro growth of cariogenic bacterial species, Streptococcus mutans. The effective minimum inhibitory concentration of abietic acid was determined through observation of S. mutans growth, acidification, and biofilm formation. The inhibitory effects of abietic acid on the bacterial membrane were investigated through the use of in situ viability analysis and scanning electron microscopic analysis. Cytotoxicity of abietic acid was also examined in the context of several human cell lines using tetrazolium reduction assay. Abietic acid was found to inhibit key bacterial growth hallmarks such as colony forming ability, adenosine triphosphate activity (both planktonic and biofilm), acid production, and biofilm formation. Abietic acid was identified as bacteriostatic, and this compound caused minimal damage to the bacterial membrane. This action was different from that of povidone-iodine or cetylpyridinium chloride. Additionally, abietic acid was significantly less cytotoxic compared to povidone-iodine, and it exerted lower toxicity towards epithelial cells and fibroblasts compared to that against monocytic cells. These data suggest that abietic acid may prove useful as an antibacterial and antibiofilm agent for controlling S. mutans infection.

Spongy wound dressing of pectin/carboxymethyl tamarind seed polysaccharide loaded with moxifloxacin beads for effective wound heal

An attempt was made to formulate moxifloxacin loaded alginate beads incorporated into spongy wound dressing to heal chronic wounds as well as to reduce frequency of painful dressing change. Moxifloxacin loaded beads (sodium alginate:pectin, 1:1) were prepared by ionic gelation method, with entrapment efficiency 94.52%, crushing strength 25.30 N and drug release 90.52%. Beads were further incorporated into wound dressing, made of pectin and carboxymethyl tamarind seed polysaccharide (CMTSP). Spongy wound dressing was obtained by freeze drying technology, which showed good folding endurance, high wound fluid absorption and good crushing strength. Drug release was found to be 85.09%. Dressing made of CMTSP:pectin (1.5:2) showed good water vapour transmission and antibacterial activity. Porous nature of dressing absorbed exudates of wound. Excision wound model in rats revealed wound healing within 17 days: groups I (control), II (moxifloxacin beads loaded wound dressing), III (moxifloxacin beads), IV (pectin film) and V (sodium alginate film) showed 65.28, 99.09, 86.90, 66.84 and 64.30% wound closure, respectively. To conclude, moxifloxacin beads loaded spongy wound dressing has good healing and wound closing potential compared to pectin film and moxifloxacin beads. Thus, the formulation is novel for biomedical application which reduced the frequency of painful dressing change.

Topical application of omega-3-, omega-6-, and omega-9-rich oil emulsions for cutaneous wound healing in rats

Wound healing is a physiological event that generates reconstitution and restoration of granulation tissue that ends with scar formation. As omega fatty acids are part of membrane phospholipids and participate in the inflammatory response, we investigated the effects of omega-3, omega-6, and omega-9 fatty acids in the form of oils on wound healing. Linseed (LO), evening primrose (EPO), and olive oils (OO) rich in omega-3, omega-6, and omega-9 fatty acids were formulated into emulsions and were topically applied on rats with excision wounds. All omega-3-, omega-6-, and omega-9-rich oil formulations were found to accelerate wound closure compared to untreated, with significant improvement (p < 0.05) being observed at day 14. EPO induced early deposition of collagen as evaluated by Masson trichrome staining that correlated well with the hydroxyproline content assay, with the highest level at days 3 and 7. Vascular endothelial growth factor (VEGF) showed greater amount of new microvasculature formed in the EPO-treated group, while moderate improvement occurs in the LO and OO groups. EPO increased both the expression of proinflammatory cytokines and growth factors in the early stage of healing and declined at the later stage of healing. LO modulates the proinflammatory cytokines and chemokine but did not affect the growth factors. In contrast, OO induced the expression of growth factors rather than proinflammatory cytokines. These data suggest that LO, EPO, and OO emulsions promote wound healing but they accomplish this by different mechanisms.

Palliative Wound Care: Less Is More

Palliative wound care is a philosophy of wound management that prioritizes comfort over healing and attends to the emotional distress these wounds can cause. Intervention strategies focus on management of symptoms such as pain, odor, bleeding, and exudate. Historic treatments such as honey, chlorine, and vinegar have gained renewed interest, and although well suited to the palliative setting, there is an increasing amount of research exploring their efficacy in other contexts. The lived experience of patients and caregivers facing these wounds is often stressful and isolating, and any treatment plan must address these issues along with the physical aspects of care.

Intraoperative povidone-iodine irrigation for infection prevention

Although prevention of infection following arthroplasty requires a multifaceted approach, the use of intraoperative irrigation is an important component of any protocol. Recent clinical practice guidelines from the Centers for Disease Control, World Health Organization, and International Consensus Meeting on Musculoskeletal Infection advocate the use of a dilute povidone-iodine solution prior to wound closure. Our experience suggests that this practice is safe, inexpensive, and easily implemented. The present article describes our institutional irrigation protocol and reviews the current literature regarding povidone-iodine solutions.

The use of povidone-iodine and sugar solution in surgical wound dehiscence in the head and neck following radio-chemotherapy

Povidone-iodine is known for successfully treating surgical wounds; the combination between povidone-iodine and sugar, also called Knutson's formula, has been proposed to improve wound healing. Currently, no studies have investigated the effects of Knutson's formula to treat defects in wound closure following radio-chemotherapy in the head and neck region. The aim of this study is to evaluate the efficacy of Knutson's formula in improving the wound-healing process in patients who underwent radio-chemotherapy after surgery for head and neck cancer. The study, conducted from August 2013 to January 2017, included a sample of 34 patients (25 males and 9 females; age range: 60-75 years) treated with radio-chemotherapy after head and neck cancer surgery. All patients suffered from defect of wound regeneration. Patients were randomly divided into two groups: patients in the study group (n = 18) were treated with Knutson's formula; patients in the control group (n = 16) were treated with traditional topical drugs. In the study group, 16 of 18 (88.9%) patients reached complete wound closure 1 month after treatment, with no wound infections. In the control group, only three patients (18.7%) showed complete wound closure within a month; in addition, one patient required systemic antibiotic treatment because of supra-bacterial infection of the wound. In our sample, the combination of povidone-iodine and sugar had a higher success rate compared with traditional topical treatment in the treatment of wound defect closure in oncological patients who underwent radio-chemotherapy.

Advancing pharmacotherapy for diabetic foot ulcers

INTRODUCTION

Standard treatment for diabetic foot ulcers (DFUs) includes off-loading, debridement, moisture balance, management of infection and peripheral arterial disease (PAD) as well as adequate glycemic control. The outcomes so far are unsatisfactory.

AREAS COVERED

Herein, the authors provide an outline of newer pharmacological agents for the management of DFUs and give their expert perspectives on future treatment strategies.

EXPERT OPINION

Evidence-based healthcare calls for high quality evidence from large RCTs before the implementation of new guidelines for the management of DFUs. Empagliflozin and liraglutide can be recommended for glucose control in patients with DFUs and PAD, while intensive lipid lowering therapy with evolocumab when primary cholesterol goals are not met could be offered to patients with DFUs. Further clinical studies are warranted to develop a structured algorithm for the treatment of DFUs that fail to heal after four weeks of current standard of care. Sucrose octasulfate dressings, becaplermin gel, and platelet-rich plasma (PRP) could also be considered as advanced treatment options for the management of hard to heal DFUs.

Modern Primary Breast Augmentation: Best Recommendations for Best Results

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Develop a practical method for preoperative implant size selection. 2. List characteristics and examples of fourth- and fifth-generation silicone implants. 3. Recognize the differences in "profile" designations across implant manufacturers. 4. Recall updated statistics on breast implant-associated anaplastic large cell lymphoma and describe current guidelines on disease diagnosis and treatment. 5. Apply atraumatic and aseptic surgical techniques in primary breast augmentation.

SUMMARY

Modern primary breast augmentation requires an intimate knowledge of the expanding breast implant market, including characteristics of current generation silicone implants and "profile" types. Optimal implant size selection requires balancing patient desires with tissue qualities. Evidence and awareness of breast implant-associated anaplastic large cell lymphoma continue to grow, and patients and surgeons alike should be informed on the most updated facts of the disease entity. Atraumatic surgical technique and aseptic adjuncts are critical in reducing periprosthetic inflammation and contamination, both of which are known instigators of capsular contracture and potentially breast implant-associated anaplastic large cell lymphoma.

Topical, systemic and biologic therapies in hidradenitis suppurativa: pathogenic insights by examining therapeutic mechanisms

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin, manifesting in chronic, recurrent painful pustules, nodules, boils and purulent draining abscesses. Our current understanding of the pathogenesis of the disease is incomplete. This review aims to identify available treatment options in HS and discuss the pharmacological mechanisms through which such agents function. Identifying common pathways may inform our understanding of the pathogenesis of HS as well as identify future therapeutic targets. The pharmacological mechanisms implicated in topical therapies, antibiotic, hormonal, systemic immunomodulatory and biologic therapies for HS are discussed. Significant differences exist between agents and implicated pathways in therapy for mild and severe disease. This is an expression of the possible dichotomy in inflammatory pathways (and treatment responses) in HS. Studies involving monoclonal antibodies provide the greatest insight into what these specific mechanisms may be. Their variable levels of clinical efficacy compared with placebo bolsters the suggestion that differential inflammatory pathways may be involved in different presentations and severity of disease. Nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and other innate immune mechanisms are strongly represented in treatments which are effective in mild to moderate disease in the absence of scarring or draining fistulae, however complex feed-forward mechanisms in severe disease respond to interleukin (IL)-1 inhibition but are less likely to respond to innate immune inhibition (through NF-κB or TNF-α) alone. It is unclear whether IL-17 inhibition will parallel TNF-α or IL-1 inhibition in effect, however it is plausible that small molecule targets (Janus kinase1 and phosphodiesterase 4) may provide effective new strategies for treatment of HS.

Comparison of the efficacy and safety of povidone-iodine foam dressing (Betafoam), hydrocellular foam dressing (Allevyn), and petrolatum gauze for split-thickness skin graft donor site dressing

We evaluated the efficacy and safety of a povidone-iodine (PVP-I) foam dressing (Betafoam) for donor site dressing versus a hydrocellular foam dressing (Allevyn) and petrolatum gauze. This prospective Phase 4 study was conducted between March 2016 and April 2017 at eight sites in Korea. A total of 106 consenting patients (aged ≥ 19 years, scheduled for split-thickness skin graft) were randomised 1:1:1 to PVP-I foam, hydrocellular, or petrolatum gauze dressings for up to 28 days after donor site collection. We assessed time to complete epithelialisation, proportion with complete epithelialisation at Day 14, and wound infection. Epithelialisation time was the shortest with PVP-I foam dressing (12.74 ± 3.51 days) versus hydrocellular foam dressing (16.61 ± 4.45 days; P = 0.0003) and petrolatum gauze (15.06 ± 4.26 days, P = 0.0205). At Day 14, 83.87% of PVP-I foam dressing donor sites had complete epithelialisation, versus 36.36% of hydrocellular foam dressing donor sites (P = 0.0001) and 55.88% of petrolatum gauze donor sites (P = 0.0146). There were no wound infections. Incidence rates of adverse events were comparable across groups (P = 0.1940). PVP-I foam dressing required less time to complete epithelialisation and had a good safety profile.

Surgical Breast Pocket Irrigation With Hypochlorous Acid (HOCl): An In Vivo Evaluation of Pocket Protein Content and Potential HOCl Antimicrobial Capacity

Background

Hypochlorous acid (HOCl) demonstrates rapid and broad antimicrobial activity against planktonic and biofilm phenotype bacteria in vitro.

Objectives

To identify the protein content present in breast pockets in vivo and calculate the estimated active concentration of HOCl, (PhaseOne, Integrated Healing Technologies, Franklin, TN) following HOCl-protein interactions.

Methods

Fluid samples were collected prior to implant insertion in 18 consecutive patients, representing 36 pocket samples, with all cases being bilateral primary breast augmentations. Samples were evaluated by an independent CLIA approved laboratory for albumin and total protein concentration in g/dL. Results were compared to HOCl solution concentration and protein binding potential to determine availability of free HOCl.

Results

The mean tissue sample concentration (right and left breast) was 31.6 mg/dL which translates to 0.0001 mmol per 20 cc of interstitial fluid. Mean total protein levels (right and left breast) were 62.3 mg/dL or 0.000187 mmol per 20 cc interstitial fluid. Based upon potential stoichiometric neutralization of HOCl by proteins in either a 1:1 or 3:1 ratio, using 115 cc of HOCl solution (per breast) at a concentration of 250 ppm/mL or 0.025% HOCl or = 0.48 mmol HOCl/dL, there would be 2950 times the amount of active HOCl at a 1:1 reaction ratio, or 983 times more HOCl assuming a 3:1 reaction ratio. Based on the range of identified levels of protein in individual surgical pockets in the study, there is an estimated 242 to 12,500 times more HOCl molecules than protein at a 3:1 molar ratio of binding or reactive protein.

Conclusions

n estimated range of 983-2950 times more HOCl molecules are present during irrigation with 230 cc of PhaseOne® (115 cc for each breast) than available protein. This supports the antimicrobial and anti-biofilm activity as described in previous in vitro studies when using PhaseOne® as part of pocket irrigation.

Level of Evidence 5

Synthesis and Characterization of Thiolated PVP-Iodine Complexes: Key to Highly Mucoadhesive Antimicrobial Gels

The aim of this study was to synthesize iodine containing polymeric excipients for mucosal treatment of microbial infection exhibiting a prolonged mucosal residence time by forming an adhesive gel on the mucosal surface. In order to achieve this aim, 2-(2 acryloylamino-ethyldisulfanyl)-nicotinic acid (ACENA) was copolymerized with N-vinylpyrrolidone (NVP) to obtain thiolated polyvinylpyrrolidone (PVP) for complexation with iodine. The average molecular mass of different thiolated PVP variants was determined by size exclusion chromatography. The structure of thiolated PVP was confirmed by ¹H NMR. Thiolated PVP variants were characterized for thiol content, cytotoxicity, iodine loading capacity, rheological behavior, and adhesion time on mucosa. The highest achieved degree of thiolation was 610 ± 43 μmol/g, and the maximum recorded iodine loading was 949 ± 31 μmol/g of polymer. Thiolated PVP variants (0.5% m/v) showed no toxicity after incubation on Caco-2 cells for the period of 3 and 24 h, respectively. Thiolated PVP and thiolated PVP-iodine complexes exhibited a 5.4- and 4.4-fold increased dynamic viscosity in porcine mucus in comparison to PVP and PVP-iodine complex, respectively. Compared to PVP and PVP-iodine complex thiol-functionalized PVP and PVP-iodine complexes demonstrated significantly prolonged attachment to mucosal surface over a period of 3 h. Thiol functionalized PVP proved to be a promising novel excipient for complexation with iodine and to exhibit strongly improved mucoadhesive properties.

Comparison of Aqueous and Alcohol-based Agents for Presurgical Skin Preparation Methods in Mice

Preparing the skin of rodents for surgery often involves multiple applications of antiseptic agents. However, fewer applications may achieve the same antiseptic outcome. We evaluated the antimicrobial efficacy and effects on intraoperative body temperature of various surgical scrub agents, including novel waterless alcohol-based (WAB) options. Prior to ventral laparotomy, female C57BL/6 mice were treated with 0.9% saline (control); 70% ethanol; 10% povidone-iodine alternated with saline or 70% ethanol; 2% chlorhexidine digluconate alternated with saline or 70% ethanol; or 1 of 3 WAB products-commercial surgical scrub A, commercial surgical scrub B, or a common commercial hand sanitizer. Core temperatures were recorded, and aerobic culture swabs were collected from the surgical site at multiple time points. Intraoperative temperature trajectories for animals treated with scrub B, 10% povidone-iodine with saline, or hand sanitizer did not differ from saline (control). Temperature trajectories of mice treated with other scrub agents did differ significantly from saline. Bacteria were not detected at the operative site after 3 scrubs of 70% ethanol or 10% povidone-iodine alternated with ethanol, 2 scrubs of scrub A or B, 1 scrub of hand sanitizer, and both 1 and 3 scrubs of 2% chlorhexidine alternated with ethanol. Scrub B and 2% chlorhexidine-ethanol demonstrated prolonged antibacterial efficacy. Histology of corresponding haired skin sections revealed no differences in postoperative healing between groups, and no postoperative infections occurred. These results indicate that various novel WAB disinfectants, particularly scrub B (61% ethanol and 1% chlorhexidine gluconate), mitigate intraoperative temperature effects associated with several traditional agents and combinations. Furthermore, reduction of skin bacterial load without adverse effects on healing was seen with fewer than triplicate applications of most tested agents. Ultimately effective skin preparation can be achieved by using only 1 or 2 applications of scrub, thus rendering the triplicate skin-prep method unnecessary in laboratory mice.

What interventions are performed in daily practice to prevent surgical site infections in neurosurgical patients? Findings from an explorative survey

Aim

The primary aim of the study was to describe the perioperative care ensured on a daily basis to prevent surgical site infection in Italian neurosurgeries; the secondary aim was to explore surgical site infections 30 days after the surgical procedures.

Methods

Patients cared for in 16 neurosurgical units who (a) were ≥18 years of age, (b) underwent neurosurgical procedures, and (c) were willing to participate in the study were taken into account.

Results

A total of 383 patients were included. A preoperative shower was performed in 332 cases (86.7%), shaving in 318 (83%) cases, and antibiotic prophylaxis was administered in 293 (76.5%) cases. Surgical site disinfection was performed mainly with povidone–iodine (344; 89.8%). A surgical site dressing was applied in 376 (98.2%) cases and was changed on average after 37.8h for shaved and 39h for non-shaved patients. Postoperative shampooing was performed only in 74 (19.3%) cases. Surgical site infection at 30 days occurred in three (0.8%) patients. Discussion and conclusions: Perioperative care aimed at preventing surgical site infections is variable across Italian neurosurgical units. More studies aimed at developing evidence capable of supporting decision-making processes in neurosurgery care are strongly recommended.

Betadine and Breast Implants

In the fourth quarter of 2017, the US FDA reviewed and approved a request by one of the breast implant manufacturers for a change in the Directions for Use (DFU) that removed warnings regarding the use of Betadine (povidone-iodine [PI] 10% solution, 1% available iodine [Purdue Frederick Company, Stamford, CT], also available in generic formulations [Aplicare, Inc., Meriden, CT]). Previously, in 2000, there were concerns by the FDA that PI would degrade the silicone elastomer shell. This change in the DFU represents an important advance that will benefit patients through the permitted use of PI to reduce the risk of bacterial contamination of implant surfaces. What was formerly an off-label practice can be openly practiced by plastic surgeons as an anti-infective and biofilm-mitigation strategy. PI has an ideal spectrum effect for gram-positive and gram-negative organisms. Gram-positive organisms have been linked to capsular contracture and gram-negative Ralstonia picketti to breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). R picketti is resistant to aminoglycoside antibiotics, but it is susceptible to at least a 50% solution of PI. We believe that the strategy of antisepsis and biofilm mitigation is an integral part of a contemporary approach for breast augmentation. This is beneficial regarding reduction of the risk of surgical infection, capsular contracture, and BIA-ALCL. Outcome data so far indicate that antibiotics/anti-infectives seem to reduce the incidence of these adverse events that lead to reoperation and increased costs. It behooves plastic surgeons to take all actionable steps that enhance the quality of breast implant outcomes and reduce the rate of reoperation.