In vitro cytotoxity of silver: implication for clinical wound care

Multifunctional Ag2O/chitosan nanocomposites synthesized via sol-gel with enhanced antimicrobial, and antioxidant properties: A novel food packaging material

In this study, a single step in situ sol-gel method was used to syntheses nanocomposite films using chitosan (CS) as the basis material, with the addition of silver oxide nanoparticles (Ag2O) at several weight percentages (5 %, 10 %, and 15 % Ag2O/CS). The structural characteristics of Ag2O/CS films were investigated using a range of analytical techniques. The presence of the primary distinctive peaks of chitosan was verified using FTIR spectra analysis. However, a minor displacement was observed in these peaks due to the chemical interaction occurring with silver oxide molecules. XRD analysis demonstrated a significant increase in the crystallinity of chitosan when it interacted with metal oxide nanoparticles. Furthermore, it is believed that the interaction between silver oxide and the active binding sites of chitosan is responsible for the evenly dispersed clusters shown in the micrographs of the chitosan surface, as well as the random aggregations within the pores. EDS technique successfully identified the presence of distinctive silver signals within the nanocomposite material, indicating the successful absorption of silver into the surface of the polymer. The developed Ag2O/CS nanocomposite showed promising antibacterial activity against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus). Also, Ag2O/CS nanocomposite exhibited marked antifungal activity against Candida albicans, Aspergillus flavus, A. fumigatus, A. niger, and Penicillium chrysogenum. The antioxidant activity of the developed nanocomposite films was studied by ABTS radical scavenging. The highest antioxidant and antibacterial properties were achieved by including 15 % silver oxide into the chitosan. Therefore, our finding indicate that chitosan‑silver oxide nanocomposites exhibits significant potential as a viable material for application in several sectors of the food packaging industry.

Strong Activity and No Resistance Induction Exerted by Cell-Free Supernatants from Lacticaseibacillus rhamnosus against Mono-Species and Dual-Species Biofilms of Wound Pathogens in In Vivo-like Conditions

It is widely agreed that microbial biofilms play a major role in promoting infection and delaying healing of chronic wounds. In the era of microbial resistance, probiotic strains or their metabolic products are emerging as an innovative approach for the treatment of hard-to-heal (chronic) wounds due to their antimicrobial, healing, and host immune-modulatory effects. In this study, we aimed to investigate the potential of cell-free supernatants (CFS) from Lacticaseibacillus rhamnosus GG against mono- and dual-species biofilms of wound pathogens in a 3D in vitro infection model. Mature biofilms of Pseudomonas aeruginosa and Staphylococcus aureus were obtained on collagen scaffolds in the presence of a simulant wound fluid (SWF) and treated with CFS at different doses and time intervals. At 1:4 dilution in SWF, CFS caused a marked reduction in the colony forming-unit (CFU) numbers of bacteria embedded in mono-species biofilms as well as bacteria released by the biofilms in the supernatant. CFU count and electron microscopy imaging also demonstrated a marked antibiofilm effect against dual-species biofilms starting from 8 h of incubation. Furthermore, CFS exhibited acceptable levels of cytotoxicity at 24 h of incubation against HaCaT cells and, differently from ciprofloxacin, failed to induce resistance after 15 passages at sub-inhibitory concentrations. Overall, the results obtained point to L. rhamnosus GG postbiotics as a promising strategy for the treatment of wound biofilms.

In Vivo Study of the Effects of Propranolol, Timolol, and Minoxidil on Burn Wound Healing in Wistar Rats

Propranolol, timolol, and minoxidil have all shown benefits in treatment of burn injury and other skin wounds. The study evaluated their effects on full-thickness thermal skin burns in a Wistar rat model. Performed on 50 female rats; two dorsal skin burns were created on each animal. On the next day, the rats were divided into 5 groups (n = 10); each has received a specific treatment daily for 14 days: group I-topical vehicle (control), group II-topical silver sulfadiazine (SSD), group III-oral propranolol (5.5 mg) associated with topical vehicle, group IV-topical timolol 1% cream, and group V-topical minoxidil 5% cream. Wound contraction rates, malondialdehyde (MDA), glutathione (GSH, GSSG), and catalase activity in skin and/or serum were evaluated, and histopathological analyses were performed. Propranolol did not show advantages in necrosis prevention and wound contraction and healing, and did not reduce oxidative stress. It impaired keratinocyte migration, and promoted ulceration, chronic inflammation, and fibrosis, yet reducing the necrotic zone. Timolol prevented necrosis and promoted contraction and healing, increased antioxidant capacity and promoted keratinocyte migration and neo capillarization in comparison to the other treatments. Minoxidil reduced necrosis and enhanced contraction, resulting in positive outcomes after 1 week of treatment regarding local antioxidant defense, keratinocyte migration, neo capillarization, chronic inflammation, and fibrosis rates. However, after 2 weeks, it resulted in contrasting outcomes. In conclusion, topical timolol promoted wound contraction and healing, reducing local oxidative stress and improving keratinocyte migration, bringing arguments for potential benefits in skin epithelization.

Multi-disciplinary management of type 1 and 2 skin tears using a silver-based hydrofiber dressing

Skin tear is a common problem encountered in the emergency department. If it is not properly managed, it can lead to wound infection, skin necrosis and a need for further surgical intervention and skin grafting. Current management is to cleanse the wound, replace the thin skin tear followed by coverage with a dressing that is inducive for wound healing. Several dressings have been suggested for the coverage of these wounds. But, up to now, there has been no mention of the use of a silver-based hydrofiber dressing in the management of this condition. The objective of this study was to explore the use of a silver-based hydrofiber dressing for the management of paper-thin skin tears. We retrospectively reviewed all patients with Type 1 or 2 skin tears that had undergone management using a silver-based hydrofiber dressing between October 2019 and October 2020. Demographic data and medical history was obtained by retrospective chart review. Data that was collected included: age, sex, comorbid illnesses, defect location, defect size, complications, number of times the silver-based hydrofiber dressing was replaced and the number of days required to achieve complete wound healing. A total of 65 patients were included in the study. There were 42 males and 23 females. There were 28 patients whose age was greater then 85 years old, of which 14 patients were over 90 years old. The mean number of outpatient visits was 2. The mean defect size was 33 cm2 (range 1 cm × 1 cm to 18 × 10 cm). The mean number of days required for total wound healing was 13 days (range 7-21). We did not encounter any patients that required further surgical debridement or split-thickness skin grafting. The use of a silver-based hydrofiber dressing was well tolerated by the elderly population as it provided an easy, efficient, economical and effective form of management of skin tears. We suggest that a silver-based hydrofiber dressing can be used as a first-line treatment method for type 1 and 2 skin tears.

SAM-Support-Based Electrochemical Sensor for Aβ Biomarker Detection of Alzheimer's Disease

Alzheimer's disease has taken the spotlight as a neurodegenerative disease which has caused crucial issues to both society and the economy. Specifically, aging populations in developed countries face an increasingly serious problem due to the increasing budget for patient care and an inadequate labor force, and therefore a solution is urgently needed. Recently, diverse techniques for the detection of Alzheimer's biomarkers have been researched and developed to support early diagnosis and treatment. Among them, electrochemical biosensors and electrode modification proved their effectiveness in the detection of the Aβ biomarker at appropriately low concentrations for practice and point-of-care application. This review discusses the production and detection ability of amyloid beta, an Alzheimer's biomarker, by electrochemical biosensors with SAM support for antibody conjugation. In addition, future perspectives on SAM for the improvement of electrochemical biosensors are also proposed and discussed.

Colloidal silver against macrophage infections and biofilms of atypical mycobacteria

Skin and soft tissue infection (SSTI) caused by atypical mycobacteria such as Mycobacterium abscessus and Mycobacterium avium intracellulare complex (MAIC) have increased in recent years. Current therapeutic options are limited, and hence new and better therapies are urgently required. Colloidal Silver (CS) has been identified for its widespread antibacterial properties and silver-impregnated dressings have been used for SSTIs caused by various pathogens. The efficacy of Green Synthesized Colloidal Silver (GSCS) was investigated for bacterial growth inhibition (BGI) using a microdilution method and minimum biofilm eradication concentration (MBEC) using resazurin assay and confocal scanning laser microscopy (CSLM) of M. abscessus (n = 5) and MAIC (n = 5). The antibacterial effect of GSCS against M. abscessus infected macrophages was also evaluated. The in vitro cytotoxicity of GSCS on a human keratinocyte cell line (HaCaT) and neonatal foreskin fibroblasts was analyzed by the crystal violet proliferation assay. Average BGI and MBEC of GSCS varied between 0.7 and 22 ppm for M. abscessus and MAIC. The concentration of 3 ppm reduced M. abscessus-infection in macrophages significantly. GSCS was not cytotoxic to HaCaT and neonatal foreskin fibroblast cells at concentrations < 3 ppm up to 2 h exposure time. GSCS therefore, has the potential for topical application against atypical mycobacterial SSTI.

Nanosilver: An Old Antibacterial Agent with Great Promise in the Fight against Antibiotic Resistance

Antibiotic resistance in bacteria is a major problem worldwide that costs 55 billion USD annually for extended hospitalization, resource utilization, and additional treatment expenditures in the United States. This review examines the roles and forms of silver (e.g., bulk Ag, silver salts (AgNO3), and colloidal Ag) from antiquity to the present, and its eventual incorporation as silver nanoparticles (AgNPs) in numerous antibacterial consumer products and biomedical applications. The AgNP fabrication methods, physicochemical properties, and antibacterial mechanisms in Gram-positive and Gram-negative bacterial models are covered. The emphasis is on the problematic ESKAPE pathogens and the antibiotic-resistant pathogens of the greatest human health concern according to the World Health Organization. This review delineates the differences between each bacterial model, the role of the physicochemical properties of AgNPs in the interaction with pathogens, and the subsequent damage of AgNPs and Ag+ released by AgNPs on structural cellular components. In closing, the processes of antibiotic resistance attainment and how novel AgNP-antibiotic conjugates may synergistically reduce the growth of antibiotic-resistant pathogens are presented in light of promising examples, where antibiotic efficacy alone is decreased.

Treatment topical with silver nanoparticles and Stryphnodendron Adstringens (Mart.) Coville in cervical lesions: randomized clinical trial

OBJECTIVE

To assess the feasibility of incorporating technology as a new alternative for treating topics on cervical lesions.

METHOD

This is a randomized, double-blind, controlled clinical trial with a prospective design. During the realization of this study, 43 women were included and divided between groups A (ointment without silver nanoparticles n = 23) and B (ointment with silver nanoparticles n = 20) clinically healthy and who used the unified health system.

RESULTS

There were no significant differences when comparing before and after the use of ointment for IVA test (p = 0.15), Schiller test (p = 0.15), cellular changes (p = 0.47) and microbiological analysis (p = 0.89) through cytology. After use, no adverse reaction was observed in the sample studied.

CONCLUSION

Based on the results identified in this study, identified that the product is safe and does not promote adverse events. Regarding the effectiveness of the product in uterine cervical lesions, it is necessary to continue the study in phase II. Registro de Ensaios Clínicos Brasileiros: UTN: U1111-1218-2820.

A Review of Metal Nanoparticles Embedded in Hydrogel Scaffolds for Wound Healing In Vivo

An evolving field, nanotechnology has made its mark in the fields of nanoscience, nanoparticles, nanomaterials, and nanomedicine. Specifically, metal nanoparticles have garnered attention for their diverse use and applicability to dressings for wound healing due to their antimicrobial properties. Given their convenient integration into wound dressings, there has been increasing focus dedicated to investigating the physical, mechanical, and biological characteristics of these nanoparticles as well as their incorporation into biocomposite materials, such as hydrogel scaffolds for use in lieu of antibiotics as well as to accelerate and ameliorate healing. Though rigorously tested and applied in both medical and non-medical applications, further investigations have not been carried out to bring metal nanoparticle-hydrogel composites into clinical practice. In this review, we provide an up-to-date, comprehensive review of advancements in the field, with emphasis on implications on wound healing in in vivo experiments.

Therapeutic applications of nanobiotechnology

Nanobiotechnology, as a novel and more specialized branch of science, has provided a number of nanostructures such as nanoparticles, by utilizing the methods, techniques, and protocols of other branches of science. Due to the unique features and physiobiological characteristics, these nanostructures or nanocarriers have provided vast methods and therapeutic techniques, against microbial infections and cancers and for tissue regeneration, tissue engineering, and immunotherapies, and for gene therapies, through drug delivery systems. However, reduced carrying capacity, abrupt and non-targeted delivery, and solubility of therapeutic agents, can affect the therapeutic applications of these biotechnological products. In this article, we explored and discussed the prominent nanobiotechnological methods and products such as nanocarriers, highlighted the features and challenges associated with these products, and attempted to conclude if available nanostructures offer any scope of improvement or enhancement. We aimed to identify and emphasize the nanobiotechnological methods and products, with greater prospect and capacity for therapeutic improvements and enhancements. We found that novel nanocarriers and nanostructures, such as nanocomposites, micelles, hydrogels, microneedles, and artificial cells, can address the associated challenges and inherited drawbacks, with help of conjugations, sustained and stimuli-responsive release, ligand binding, and targeted delivery. We recommend that nanobiotechnology, despite having few challenges and drawbacks, offers immense opportunities that can be harnessed in delivering quality therapeutics with precision and prediction. We also recommend that, by exploring the branched domains more rigorously, bottlenecks and obstacles can also be addressed and resolved in return.

Pluronic® F127 Hydrogel Containing Silver Nanoparticles in Skin Burn Regeneration: An Experimental Approach from Fundamental to Translational Research

Presently, skin burns are considered one of the main public health problems and lack therapeutic options. In recent years, silver nanoparticles (AgNPs) have been widely studied, playing an increasingly important role in wound healing due to their antibacterial activity. This work is focused on the production and characterization of AgNPs loaded in a Pluronic® F127 hydrogel, as well as assessing its antimicrobial and wound-healing potential. Pluronic® F127 has been extensively explored for therapeutic applications mainly due to its appealing properties. The developed AgNPs had an average size of 48.04 ± 14.87 nm (when prepared by method C) and a negative surface charge. Macroscopically, the AgNPs solution presented a translucent yellow coloration with a characteristic absorption peak at 407 nm. Microscopically, the AgNPs presented a multiform morphology with small sizes (~50 nm). Skin permeation studies revealed that no AgNPs permeated the skin after 24 h. AgNPs further demonstrated antimicrobial activity against different bacterial species predominant in burns. A chemical burn model was developed to perform preliminary in vivo assays and the results showed that the performance of the developed AgNPs loaded in hydrogel, with smaller silver dose, was comparable with a commercial silver cream using higher doses. In conclusion, hydrogel-loaded AgNPs is potentially an important resource in the treatment of skin burns due to their proven efficacy by topical administration.

Silver Nanoparticles Phytofabricated through Azadirachta indica: Anticancer, Apoptotic, and Wound-Healing Properties

Silver nanoparticles (AgNPs) have unlocked numerous novel disciplines in nanobiotechnological protocols due to their larger surface area-to-volume ratios, which are attributed to the marked reactivity of nanosilver, and due to their extremely small size, which enables AgNPs to enter cells, interact with organelles, and yield distinct biological effects. AgNPs are capable of bypassing immune cells, staying in the system for longer periods and with a higher distribution, reaching target tissues at higher concentrations, avoiding diffusion to adjacent tissues, releasing therapeutic agents or drugs for specific stimuli to achieve a longer duration at a specific rate, and yielding desired effects. The phytofabrication of AgNPs is a cost-effective, one-step, environmentally friendly, and easy method that harnesses sustainable resources and naturally available components of plant extracts (PEs). In addition, it processes various catalytic activities for the degradation of various organic pollutants. For the phytofabrication of AgNPs, plant products can be used in a multifunctional manner as a reducing agent, a stabilizing agent, and a functionalizing agent. In addition, they can be used to curtail the requirements for any additional stabilizing agents and to help the reaction stages subside. Azadirachta indica, a very common and prominent medicinal plant grown throughout the Indian subcontinent, possesses free radical scavenging and other pharmaceutical properties via the regulation of proinflammatory enzymes, such as COX and TOX. It also demonstrates anticancer activities through cell-signaling pathways, modulating tumor-suppressing genes such as p53 and pTEN, transcriptional factors, angiogenesis, and apoptosis via bcl2 and bax. In addition, it possesses antibacterial activities. Phytofabricated AgNPs have been applied in the areas of drug delivery, bioimaging, biosensing, cancer treatment, cosmetics, and cell biology. Such pharmaceutical and biological activities of phytofabricated AgNPs are attributed to more than 300 phytochemicals found in Azadirachta indica, and are especially abundant in flavonoids, polyphenols, diterpenoids, triterpenoids, limonoids, tannins, coumarin, nimbolide, azadirachtin, azadirone, azadiradione, and gedunin. Parts of Azadirachta indica, including the leaves in various forms, have been used for wound healing or as a repellent. This study was aimed at examining previously biosynthesized (from Azadirachta indica) AgNPs for anticancer, wound-healing, and antimicrobial actions (through MTT reduction assay, scratch assay, and microbroth dilution methods, respectively). Additionally, apoptosis in cancer cells and the antibiofilm capabilities of AgNPs were examined through caspase-3 expression, dentine block, and crystal violet methods. We found that biogenic silver nanoparticles are capable of inducing cytotoxicity in HCT-116 colon carcinoma cells (IC50 of 744.23 µg/mL, R2: 0.94), but are ineffective against MCF-7 breast cancer cells (IC50 >> 1000 µg/mL, R2: 0.86). AgNPs (IC50 value) induced a significant increase in caspase-3 expression (a 1.5-fold increase) in HCT-116, as compared with control cells. FITC-MFI was 1936 in HCT-116-treated cells, as compared to being 4551 in cisplatin and 1297 in untreated cells. AgNPs (6.26 µg/mL and 62.5 µg/mL) induced the cellular migration (40.2% and 33.23%, respectively) of V79 Chinese hamster lung fibroblasts; however, the improvement in wound healing was not significant as it was for the controls. AgNPs (MIC of 10 µg/mL) were very effective against MDR Enterococcus faecalis in the planktonic mode as well as in the biofilm mode. AgNPs (10 µg/mL and 320 µg/mL) reduced the E. faecalis biofilm by >50% and >80%, respectively. Natural products, such as Syzygium aromaticum (clove) oil (MIC of 312.5 µg/mL) and eugenol (MIC of 625 µg/mL), showed significant antimicrobial effects against A. indica. Our findings indicate that A. indica-functionalized AgNPs are effective against cancer cells and can induce apoptosis in HCT-116 colon carcinoma cells; however, the anticancer properties of AgNPs can also be upgraded through active targeting (functionalized with enzymes, antibiotics, photosensitizers, or antibodies) in immunotherapy, photothermal therapy, and photodynamic therapy. Our findings also suggest that functionalized AgNPs could be pivotal in the development of a novel, non-cytotoxic, biocompatible therapeutic agent for infected chronic wounds, ulcers, and skin lesions involving MDR pathogens via their incorporation into scaffolds, composites, patches, microgels, or formulations for microneedles, dressings, bandages, gels, or other drug-delivery systems.

Fluorescence-Responsive Detection of Ag(I), Al(III), and Cr(III) Ions Using Cd(II) Based Pillared-Layer Frameworks

Two Cd(II) based coordination polymers, {Cd₃(btc)₂(BTD-bpy)₂]∙1.5MeOH∙4H₂O}_n (1) and [Cd₂(1,4-ndc)₂(BTD-bpy)₂]_n (2), where BTD-bpy = bis(pyridin-4-yl)benzothiadiazole, btc = benzene-1,3,5-tricarboxylate, and 1,4-ndc = naphthalene-1,4-dicarboxylate, were hydro(solvo)thermally synthesized. Compound 1 has a three-dimensional non-interpenetrating pillared-bilayer open framework with sufficient free voids of 25.1%, which is simplified to show a topological (4,6,8)-connected net with the point symbol of (3²4²56)(3⁴4⁴5⁴6²8)(3⁴4²6¹⁹7²8). Compound 2 has a three-dimensional two-fold interpenetrating bipillared-layer condense framework regarded as a 6-connected primitive cubic (pcu) net topology. Compounds 1 and 2 both exhibited good water stability and high thermal stability approaching 350 °C. Upon excitation, compounds 1 and 2 both emitted blue light fluorescence at 471 and 479 nm, respectively, in solid state and at 457 and 446 nm, respectively, in the suspension phase of H₂O. Moreover, compounds 1 and 2 in the suspension phase of H₂O both exhibited a fluorescence quenching effect in sensing Ag⁺, attributed to framework collapse, and a fluorescence enhancement response in sensing Al³⁺ and Cr³⁺, ascribed to weak ion-framework interactions, with high selectivity and sensitivity and low detection limit.

Cellular and Molecular Events of Wound Healing and the Potential of Silver Based Nanoformulations as Wound Healing Agents

Chronic wounds are a silent epidemic threatening the lives of many people worldwide. They are associated with social, health care and economic burdens and can lead to death if left untreated. The treatment of chronic wounds is very challenging as it may not be fully effective and may be associated with various adverse effects. New wound healing agents that are potentially more effective are being discovered continuously to combat these chronic wounds. These agents include silver nanoformulations which can contain nanoparticles or nanocomposites. To be effective, the discovered agents need to have good wound healing properties which will enhance their effectiveness in the different stages of wound healing. This review will focus on the process of wound healing and describe the properties of silver nanoformulations that contribute to wound healing.

The Efficacy of Honey Compared to Silver Sulfadiazine for Burn Wound Dressing in Superficial and Partial Thickness Burns—A Systematic Review and Meta-Analysis

Burn dressings play a vital role in protecting the patient from infection and aiding in the wound healing process. At present, the best burn wound dressing remains unknown. This study aimed to assess the efficacy of honey versus silver sulfadiazine dressing (SSD) for the treatment of superficial and partial thickness burns. We performed a systematic review and meta-analysis using the PubMed, MEDLINE and Embase databases to find relevant randomised control trials (RCTs) for inclusion. The outcomes measures included complete burn wound healing time, the proportion of wounds rendered sterile and subjective pain relief associated with the respective dressing type. This review was completed in line with PRISMA guidelines and has been registered with PROSPERO (Study ID: CRD42022337433). All studies in the English language that assessed honey versus SSD for patients with superficial or partial thickness burns were included. Quality and risk of bias assessments were performed using the Cochrane RoB2 tool. Seven studies were identified: totalling a population of 582 patients. From three studies, meta-analysis showed no significant difference in complete wound healing time (p = 0.06). Meta-analysis from five studies highlighted an overall significant difference favouring honey dressing in the proportion of wounds rendered sterile at day 7 post-injury (OR 10.80; 95% CI [5.76, 20.26]; p < 0.00001; I2 = 88%). We conclude that honey dressings may be as or more effective than SSD in the treatment of superficial and partial thickness burn injuries. However, due to the low quality of available studies in this field, further research is necessary to establish the optimum burn dressing. Ideally, this should be conducted in the form of prospective three-arm RCTs in accordance with the CONSORT statement.

Alginate dressings continuously for fourteen days on uncontaminated, superficial, partial thickness burns

Calcium alginate dressings are commonly used on split-thickness skin donor sites, where they are typically removed after 14 days. Alginates have been used previously on superficial, partial thickness burns, but changed every 3-4 days. In this study, alginates were applied to superficial, partial thickness burns on adults within 36 hours of injury, then left intact for up to 14 days. Wound healing (≥95% wound epithelialisation) and pain were measured. Twenty-one burns were reviewed on ten patients. Per the initial protocol, six patients were reviewed every 3-5 days, with removal of only secondary dressings, until day 13-14, when the alginate dressings were removed. One patient was reviewed every 3-5 days until day 10, when a clinic nurse removed the alginate dressing. Restrictions on movement during the COVID pandemic necessitated a protocol change, with only one review at approximately day 14 for removal of alginate and secondary dressings; three patients were reviewed in this manner. Burns on all patients were 100% epithelialised at the time of final review and there were no complications, such as scarring, infection, or need for grafting. Following initial debridement and dressings, patients reported minimal pain. Dressing costs appeared to be significantly decreased. This protocol may be particularly useful for patients managed in rural and remote locations, with telemedicine support if required.

A Systematic Review and Meta-Analysis Comparing Burn Healing Outcomes Between Silver Sulfadiazine and Aloe vera

Burn wounds remain a prevalent problem in the developed and developing world. A multitude of remedies has been tested. This study evaluated the healing time of second- and third-degree burn wounds between silver sulfadiazine (SSD) and Aloe vera (AV). In July 2020, a systematic review of MEDLINE (Ovid) and PubMed (National Library of Medicine) was performed to identify studies that reported healing of second- and third-degree burns using either SSD or AV. Articles meeting the inclusion criteria were screened and carefully analyzed. Our goal was to report the healing time for these burns using SSD and AV. A total of eight studies published between 1988 and 2018 reporting healing of second- and third-degree burns using SSD and AV were included in this review. Six were cohort studies and two were randomized controlled trials. The studies included both animal and human subjects. The meta-analysis demonstrated that the mean time to wound healing favored AV (RR: -1.34, 95% CI: -1.8 to 0.9, p < 0.001). It would seem that time to healing benefitted those burns in which AV was utilized. In conclusion, increased consideration and emphasis should be placed on using AV to aid the healing of second- and third-degree burns.

Silver as an Antibiotic-Independent Antimicrobial: Review of Current Formulations and Clinical Relevance

Background: The increase of multi-drug-resistant organisms has revived the use of silver as an alternative antibiotic-independent antimicrobial. Although silver's multimodal mechanism of action provides low risk for bacterial resistance, high local and uncontrolled concentrations have shown toxicity. This has resulted in efforts to develop novel silver formulations that are safer and more predictable in their application. Optimization of silver as an antimicrobial is crucial given the growing resistance profile against antibiotics. This article reviews formulations of silver used as antimicrobials, focusing on the mechanisms of action, potential for toxicity, and clinical applications. Methods: A search of four electronic databases (PubMed, Embase, MEDLINE, and Cochrane Library) was conducted for relevant studies up to January 2022. Searches were conducted for the following types of silver: ionic, nanoparticles, colloidal, silver nitrate, silver sulfadiazine, silver oxide, silver carboxylate, and AQUACEL^® (ConvaTec, Berkshire, UK). Sources were compiled based on title and abstract and screened for inclusion based on relevance and study design. Results: A review of the antimicrobial activity and uses of ionic silver, silver nanoparticles, colloidal silver, silver nitrate, silver sulfadiazine, silver oxide, Aquacel, and silver carboxylate was conducted. The mechanisms of action, clinical uses, and potential for toxicity were studied, and general trends between earlier and more advanced formulations noted. Conclusions: Early forms of silver have more limited utility because of their uncontrolled release of silver ions and potential for systemic toxicity. Multiple new formulations show promise; however, there is a need for more prospective in vivo studies to validate the clinical potential of these formulations.

Hormesis: Wound healing and keratinocytes

Hormetic dose responses (i.e., a biphasic dose/concentration response characterized by a low dose stimulation and a high dose inhibition) are shown herein to be commonly reported in the dermal wound healing process, with the particular focus on cell viability, proliferation, and migration of human keratinocytes in in vitro studies. Hormetic responses are induced by a wide range of substances, including endogenous agents, numerous drug and nanoparticle preparations and especially plant derived extracts, including many well-known dietary supplements as well as physical stressor agents, such as low-level laser treatments. Detailed mechanistic studies have identified common signaling pathways and their cross-pathway communications that mediate the hormetic dose responses. These findings suggest that the concept of hormesis plays a fundamental role in wound healing, with important potential implications for agent screening and evaluation, as well as clinical strategies.

Green synthesis of silver nanoparticles and their antibacterial effects

Antibacterial resistance is by far one of the greatest challenges to global health. Many pharmaceutical or material strategies have been explored to overcome this dilemma. Of these, silver nanoparticles (AgNPs) are known to have a non-specific antibacterial mechanism that renders it difficult to engender silver-resistant bacteria, enabling them to be more powerful antibacterial agents than conventional antibiotics. AgNPs have shown promising antibacterial effects in both Gram-positive and Gram-negative bacteria. The aim of this review is to summarize the green synthesis of AgNPs as antibacterial agents, while other AgNPs-related insights (e.g., antibacterial mechanisms, potential toxicity, and medical applications) are also reviewed.

Phytochemical profile, in vivo anti-inflammatory and wound healing activities of the aqueous extract from aerial parts of Cistus ladanifer L

Cistus ladanifer L. is a Mediterranean shrub, well recognized for its many pharmacological properties. The present study aimed to investigate the phytochemical profile, the in vivo anti-inflammatory and the wound healing activities of the aqueous extract from its aerial parts (AECL). The in vivo anti-inflammatory and the wound healing properties were evaluated by carrageenan-induced paw edema (CAECL) and burn wound in rats, respectively. The results showed that six compounds belonging to flavonoids and tannins were identified in the AECL extract. Moreover, the AECL administrated orally at a dose of 500 mg/kg significantly reduced edema with a percentage of 72 % in terms of inflammation inhibition, using indomethacin as reference drug. On the other hand, when administrated topically, both doses of CAECL cream (5 % and 10 %) manifested a significant anti-inflammatory action using diclofenac as reference drug with a percentage reduction of inflammation that reached 85 % (CAECL-10). As far as wound healing is concerned, the CAECL showed higher effect at a dose of 10 % (CAECL-10) producing a wound contraction of 96 %, similar to that of the reference drug. The findings of the present study indicate that the aqueous extract from aerial parts of Cistus ladanifer L. display strongly anti-inflammatory and wound healing effects to be advantageously used for medical purposes.

Borate Bioactive Glasses (BBG): Bone Regeneration, Wound Healing Applications, and Future Directions

Since the early 2000s, borate bioactive glasses (BBGs) have been extensively investigated for biomedical applications. The research so far indicates that BBGs frequently exhibit superior bioactivity and bone healing capacity compared to silicate glasses. They are also suitable candidates as drug delivery devices for infection or disease treatment such as osteoporosis. Additionally, BBGs are also an excellent option for wound healing applications, which includes the availability of commercial (FDA approved) microfibrous BBG dressings to treat chronic wounds. By addition of modifying ions, the bone or wound healing capacity of BBGs can be enhanced. For instance, addition of copper ions into BBGs was shown to drastically increase blood vessel formation for wound healing applications. Moreover, addition of ions such as magnesium, strontium, and cobalt improves bone healing. Other recent research interest related to BBGs is focused on nerve and muscle regeneration applications, while cartilage regeneration is also suggested as a potential application field for BBGs. BBGs are commonly produced by melt-quenching; however, sol-gel processing of BBGs is emerging and appears to be a promising alternative. In this review paper, the physical and biological characteristics of BBGs are analyzed based on the available literature, the applications of BBGs are discussed, and future research directions are suggested.

Wide Spectrum Potent Antimicrobial Efficacy of Wound Dressings Impregnated with Cuprous Oxide Microparticles

Copper has intrinsic antimicrobial properties. Wound dressings impregnated with cuprous oxide microparticles (hereafter termed COD) have been cleared for the management of acute and chronic wounds by the FDA and other regulatory bodies. The COD reduced the viable microbial titers of a wide spectrum of microbes by more than 10,000-fold (4-logs) within 3 h of exposure at 37 °C (p < 0.001). Similar microbial titer reductions were achieved by 3-year naturally aged COD dressings, showing the stability of the biocidal efficacy over time. The potent biocidal efficacy of the COD was maintained even after 7 daily consecutive inoculations of the dressings with ~106 CFU. COD with an adhesive contour blocked the passage of bacteria from the exterior environment to the wound bed side of the dressing even after 7 daily consecutive inoculations of different bacteria on the outer surface of the dressings. Taken together, the study demonstrates the wide spectrum potent in vitro biocidal efficacy of the cuprous oxide impregnated dressings against a wide panel of microorganisms.

Nanostructured Polyacrylamide Hydrogels with Improved Mechanical Properties and Antimicrobial Behavior

This work proposes a simple method to obtain nanostructured hydrogels with improved mechanical characteristics and relevant antibacterial behavior for applications in articular cartilage regeneration and repair. Low amounts of silver-decorated carbon-nanotubes (Ag@CNTs) were used as reinforcing agents of the semi-interpenetrating polymer network, consisting of linear polyacrylamide (PAAm) embedded in a PAAm-methylene-bis-acrylamide (MBA) hydrogel. The rational design of the materials considered a specific purpose for each employed species: (1) the classical PAAm-MBA network provides the backbone of the materials; (2) the linear PAAm (i) aids the dispersion of the nanospecies, ensuring the systems' homogeneity and (ii) enhances the mechanical properties of the materials with regard to resilience at repeated compressions and ultimate compression stress, as shown by the specific mechanical tests; and (3) the Ag@CNTs (i) reinforce the materials, making them more robust, and (ii) imprint antimicrobial characteristics on the obtained scaffolds. The tests also showed that the obtained materials are stable, exhibiting little degradation after 4 weeks of incubation in phosphate-buffered saline. Furthermore, as revealed by micro-computed tomography, the morphometric features of the scaffolds are adequate for applications in the field of articular tissue regeneration and repair.

Emerging trends of nanotechnology in advanced cosmetics

The cosmetic industry is dynamic and ever-evolving. Especially with the introduction and incorporation of nanotechnology-based approaches into cosmetics for evincing novel formulations that confers aesthetic as well as therapeutic benefits. Nanocosmetics acts via numerous delivery mechanisms which involves lipid nanocarrier systems, polymeric or metallic nanoparticles, nanocapsules, dendrimers, nanosponges,etc. Each of these, have particular characteristic properties, which facilitates increased drug loading, enhanced absorption, better cosmetic efficacy, and many more. This article discusses the different classes of nanotechnology-based cosmetics and the nanomaterials used for their formulation, followed by outlining the categories of nanocosmetics and the scope of their utility pertaining to skin, hair, nail, lip, and/or dental care and protection thereof. This review also highlights and discusses about the key drivers of the cosmetic industry and the impending need of corroborating a healthy regulatory framework, refocusing attention towards consumer needs and trends, inculcating sustainable techniques and tenets of green ecological principles, and lastly making strides in nano-technological advancements which will further propel the growth of the cosmetic industry.

Recent technological advances in the management of chronic wounds: A literature review

Background

Wound treatment comprises a substantial portion of the healthcare budgets in developed countries. Studies suggest that about 50% of patients admitted to hospitals have wounds, while 1%−2% of the general population in the developed world suffers from chronic wounds. Chronic wounds fail to repair themselves within the expected period of 30 days. Technologies have been developed to address challenges encountered during wound care with the aim of alleviating pain, promoting healing, or controlling wound infections.

Objective

The objective of this study was to explore the technological improvements that have been made in this field over time.

Methods

To gain insight into the future of wound management, a systematic review of literature on the subject was conducted in scientific databases (PubMed, Scopus, Web of Science, Medline, and Clinical Trials).

Results and Discussion

Results indicate that wound dressings have evolved from the traditional cotton gauze to composite materials embedded with appropriate ingredients such as metal‐based nanoparticles. Studies on biodegradable dressing materials are also underway to explore their applicability in dressing large and irregular wounds. On the other hand, conventional drugs and traditional formulations for the management of pain, inflammation, infections, and accelerating healing have been developed. However, more research needs to be carried out to address the issue of microbial resistance to drugs. Drugs for managing other ailments also need to be designed in such a way that they can augment wound healing. In addition, it has been demonstrated that a coordinated integration of conventional and traditional medicine can produce laudable results in chronic wound management.

Conclusion

Accordingly, collaborative efforts and ingenuity of all players in the field can accelerate technological advances in the wound care market to the benefit of the patients.

Wounds affect about 50% of patients admitted to hospitals.

Technologies have been developed including biodegradable dressing materials to address underlying challenges.

Technological advancement, rising incidences of chronic wounds, growing government support, and a rising elderly population will drive wound market growth.

A careful combination of recent research outputs can greatly change wound care technologies.

This review highlights the recent research advances and opportunities in the wound care field.

The future lies in biodegradable dressing materials, probably embedded with selected nanoparticles and which shall be combined in predetermined ratios.

The effect of NPWT in wound healing and bacterial count on deep dermal burn injury model: An experimental study

Background

Sepsis is one of the main causes in burn victim's mortality. The use of negative pressure wound therapy (NPWT) provides an ideal environment to accelerate wound healing. We compare the use of normal saline (NS), intermittent NPWT, continuous NPWT and silver sulfadiazine in wound healing process.

Method

This study involved 6 Yorkshire pigs; each pig was induced with 20 burns on the flank area. Burns were divided into 4 treatment groups: NS gauze, intermittent NPWT, continuous NPWT, and silver sulfadiazine dressing. Burns were evaluated on day 1,3,7,14, and 21 for its morphology and bacterial colonization and on day 14 and 21 for the remaining burn surface area.

Result

Wound that received NPWT therapy appeared better in both granulation and crust formation. Remaining burn surface area (mm²) on day 14 in NS group, intermittent NPWT, continuous NPWT, and silver sulfadiazine were 107.43 ± 83.43, 178.07 ± 74.83, 146.10 ± 69.1, 126.03 ± 83.22, respectively(p = 0.457); on day 21 in NS group, intermittent NPWT, continuous NPWT, and silver sulfadiazine were 13.16 ± 16.86, 59.49 ± 20.72, 54.79 ± 46.59, 48.95 ± 39.84, respectively(p=0.169). There were no significant differences in each treatment group bacterial colonization(p>0.05). There were no significant correlation between bacterial colonization and remaining burn surface area (p>0.05).

Conclusion

While morphologically, the wound in NPWT treatment groups appeared better in granulation and crust formation, the remaining wound surface area and the number of bacterial colonization were not significantly difference compared to standard therapy (silver sulfadiazine and NS gauze). There were no significant correlation between the amount of bacterial colonization and remaining wound surface area on every treatment group.

•

Sepsis is one of cause burn injury mortality.

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NPWT is promising burn injury treatment.

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There was no significant difference of wound healing in various treatments.

Synthesis of Chitosan-Silver Nanoparticle Composite Spheres and Their Antimicrobial Activities

Synthesis of silver nanoparticles–chitosan composite particles sphere (AgNPs-chi-spheres) has been completed and its characterization was fulfilled by UV–vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and zetasizer nano. UV–vis spectroscopy characterization showed that AgNPs-chi-spheres gave optimum absorption at a wavelength of 410 nm. The XRD spectra showed that the structure of AgNPs-chi-spheres were crystalline and spherical. Characterization by SEM showed that AgNPs-chi-spheres, with the addition of 20% of NaOH, resulted in the lowest average particle sizes of 46.91 nm. EDX analysis also showed that AgNPs-chi-spheres, with the addition of a 20% NaOH concentration, produced particles with regular spheres, a smooth and relatively nonporous structure. The analysis using zetasizer nano showed that the zeta potential value and the polydispersity index value of the AgNPs-chi-sphere tended to increase with an increased NaOH concentration. The results of the microbial activity screening showed that the AgNP-chi-Spheres with highest concentration of NaOH, produced the highest inhibition zone diameters against S. aureus, E. coli, and C. albicans, with inhibition zone diameters of 19.5, 18.56, and 12.25 nm, respectively.

Cholesteric Molecular Tweezer Artificial Receptor for Rapid and Highly Selective Detection of Ag+ in Food Samples

Chiral cholesteric molecular tweezer 7a was synthesized, and its recognition properties for Ag⁺, Al³⁺, Ca²⁺ etc., were investigated by UV and fluorescence spectra. The results showed that in ethanol/Tris (1/1, v/v, pH 7.0) buffer solution, the host molecular tweezer 7a had a specific recognition ability for Ag⁺, the detection limit was up to 1 × 10⁻⁶ mol/L, and other metal ions had little effect on Ag⁺ recognition. At the same time, the naked-eye detection of Ag⁺ was realized by the light red color of the complex solution. Furthermore, the mechanism of recognition of Ag⁺ by molecular tweezer 7a was studied by a nuclear magnetic titration test and computer molecular simulation, and a rapid detection method of Ag⁺ using host molecular tweezer 7a was established. Through the determination of Ag⁺ in milk powder, quinoa and other food samples, it was proved that this novel method had a good application prospect for the detection of Ag⁺ in food.

The revolution of cosmeceuticals delivery by using nanotechnology: A narrative review of advantages and side effects

BACKGROUND

The qualified and paradigm jump in the formulation and production of cosmeceuticals refer in some way to the great revolution in nanotechnology. Nowadays, the industry of nano-formulated cosmeceuticals plays a significant and essential role in the evolution and growth of the pharmaceutical industries. This review manuscript focuses on the use of nanocarriers in delivering the cosmetic agents into the target area such as skin, hair, and nails.

METHODS

Many steps were performed in the preparation of this review including identification of different classes of nanocarriers for delivery of nanocosmeceuticals, literature survey of relevantstudies regarding the applications of nanotechnology in cosmeceuticals and their toxicological effects.

RESULTS

When nanoparticles introduced in the cosmetic industry, the quality and the elegance of the final products were raised significantly. Sadly, this revolution is accompanied by many health hazards as these tiny molecules can penetrate intact skin barriers and cause undesired effects. Cosmeceuticals with nanotechnology include sunscreens, hair cleansing products, nail products, and agents fighting fine lines.

CONCLUSIONS

The expansion and growth of the cosmetic industry and the introduction of nanotechnology in cosmeceuticals industry necessitates the urgent need for scientific research investigating their efficacy, safety profile and use.

Incorporation of Silver Nanoparticles in Hydrogel Matrices for Controlling Wound Infection

For centuries, silver has been recognized for its antibacterial properties. With the development of nanotechnology, silver nanoparticles (AgNPs) have garnered significant attention for their diverse uses in antimicrobial gel formulations, dressings for wound healing, orthopedic applications, medical catheters and instruments, implants, and contact lens coatings. A major focus has been determining AgNPs' physical, chemical, and biological characteristics and their potential to be incorporated in biocomposite materials, particularly hydrogel scaffolds, for burn and wound healing. Though AgNPs have been rigorously explored and extensively utilized in medical and nonmedical applications, important research is still needed to elucidate their antibacterial activity when incorporated in wound-healing scaffolds. In this review, we provide an up-to-date, 10-yr (2010-2019), comprehensive literature review on advancements in the understanding of AgNP characteristics, including the particles' preparation and mechanisms of activity, and we explore various hydrogel scaffolds for delivering AgNPs.

Histopathological Changes of Organs (Lungs, Liver, Kidney, and Brain) After Using Two Types of AgiCoat and Acticoat Nanosilver Dressings on Deep Second-Degree Burn in Rat

Prevention of infections is a very important issue in treating the burn wounds. The nanosilver dressings have many promising advantages, but absorption of silver ions and its adverse effects to the body were always a question. The aim of this study was to compare Silver serum levels and acute toxic effects of nanosilver on histopathology of organs (lungs, liver, kidney, spleen, and brain) in two types of AgiCoat and Acticoat (nanosilver) dressings on second-degree deep burn in rat. This is an experimental study conducted in our animal laboratory. We divided 24 Sprague-Dawley male rats weighing 300 to 350 randomly into two groups. After anesthesia, a second deep-degree burn was made over dorsal skins of rats by standard method. For group A, Agicoat and, for group B, Acticoat dressings were used. The dressings were changed every 3 days with AgiCoat and Acticoat, respectively. After 14 days, we got blood samples and tissue samples taken from heart, liver, kidneys, spleen, lungs, and brain and a sample from dorsal skin of the rat for histopathological examinations. The results showed that the levels of serum silver in both groups were significantly higher than the standard level (1.22 part per million (PM); AgiCoat, P = .017; Acticoat, P = .000), but there was no significant difference between the groups (P = .551). Examination of the relationship between the level of serum silver and histopathological changes in liver showed that hepatotoxicity of AgiCoat was higher compared with Acticoat and the difference was significant (P = .002). There were no pathological changes in brain, kidneys, spleen, heart, and lungs. Wound healing was faster in Acticoat group. The nanosilver dressings can cause toxicity in liver but not in kidney, brain, spleen, heart, and lungs. Liver pathology and hepatotoxicity were more prominent in AgiCoat group. Wound healing was faster in Acticoat group.

In Vitro Microbiological and Drug Release of Silver/Ibuprofen Loaded Wound Dressing Designed for the Treatment of Chronically Infected Painful Wounds

This study consisted of developing a dressing loaded with silver (Ag) and ibuprofen (IBU) that provides a dual therapy, antibacterial and antalgic, intended for infected painful wounds. Therefore, non-woven polyethyleneterephtalate (PET) textiles nonwovens were pre-treated by cyclodextrin crosslinked with citric acid by a pad/dry/cure process. Then, textiles were impregnated in silver solution followed by a thermal treatment and were then coated by Layer-by-Layer (L-b-L) deposition of a polyelectrolyte multilayer (PEM) system consisting of anionic water-soluble poly(betacyclodextrin citrate) (PCD) and cationic chitosan. Finally, ibuprofen lysinate (IBU-L) was loaded on the PEM coating. We demonstrated the complexation of IBU with native βCD and PCD by phase solubility diagram and ¹H NMR. PEM system allowed complete IBU-L release in 6 h in PBS pH 7.4 batch (USP IV). On the other hand, microbiological tests demonstrated that loaded silver induced bacterial reduction of 4 Log₁₀ against S. aureus and E. coli and tests revealed that ibuprofen lysinate loading did not interfere with the antibacterial properties of the dressing.

Investigation of the Long-Term Antibacterial Properties of Titanium by Two-Step Micro-Arc Oxidation Treatment

Recently, biofilm formation caused by bacterial adhesion and colonization has been recognized as the major cause of failure in orthopedic and dental implant surgeries. In this study, a customized micro-arc oxidation (MAO) treatment technique was developed to obtain desirable antibacterial properties on Ti surfaces. The two-step MAO treatment was applied in the fabrication of specimens with Ag and with/without Zn in their surface oxide layer. In order to simulate practical usage, surface analyses and immersion tests were performed to evaluate the incorporation of Ag and Zn into the resulting oxide layer and ion release behavior, respectively. Additionally, the antibacterial properties of the specimens after long-term immersion in physiological saline were evaluated using Gram-negative facultative anaerobic bacteria. The MAO-treated specimens containing Ag and Zn exhibited excellent antibacterial properties against Escherichia coli, which were sustained even after 6 months of immersion in physiological saline to simulate practical usage. Moreover, the Ag ions released from the surface oxide indicate the antibacterial properties of the specimen in the early stage, while the release of the corrosion products of Zn demonstrates its antibacterial properties in the later stage.

Update on the role of antiseptics in the management of chronic wounds with critical colonisation and/or biofilm

Biofilms play a major role in delaying chronic wounds from healing. A wound infiltrated with biofilm, or "critically colonised" wound, may become clinically infected if the number of microbes exceeds a critical level. Chronic wound biofilms represent a significant treatment challenge by demonstrating recalcitrance towards antimicrobial agents. However, a "window of opportunity" may exist after wound debridement when biofilms are more susceptible to topical antiseptics. Here, we discuss the role of antiseptics in the management of chronic wounds and biofilm, focusing on povidone-iodine (PVP-I) in comparison with two commonly used antiseptics: polyhexanide (PHMB) and silver. This article is based on the literature reviewed during a focus group meeting on antiseptics in wound care and biofilm management, and on a PubMed search conducted in March 2020. Compared with PHMB and silver, PVP-I has a broader spectrum of antimicrobial activity, potent antibiofilm efficacy, no acquired bacterial resistance or cross-resistance, low cytotoxicity, good tolerability, and an ability to promote wound healing. PVP-I represents a viable therapeutic option in wound care and biofilm management, with the potential to treat biofilm-infiltrated, critically colonised wounds. We propose a practical algorithm to guide the management of chronic, non-healing wounds due to critical colonisation or biofilm, using PVP-I.

Applications of Nanosized-Lipid-Based Drug Delivery Systems in Wound Care

Impaired wound healing is an encumbering public health issue that increases the demand for developing new therapies in order to minimize health costs and enhance treatment efficacy. Available conventional therapies are still unable to maximize their potential in penetrating the skin at the target site and accelerating the healing process. Nanotechnology exhibits an excellent opportunity to enrich currently available medical treatments, enhance standard care and manage wounds. It is a promising approach, able to address issues such as the permeability and bioavailability of drugs with reduced stability or low water solubility. This paper focuses on nanosized-lipid-based drug delivery systems, describing their numerous applications in managing skin wounds. We also highlight the relationship between the physicochemical characteristics of nanosized, lipid-based drug delivery systems and their impact on the wound-healing process. Different types of nanosized-lipid-based drug delivery systems, such as vesicular systems and lipid nanoparticles, demonstrated better applicability and enhanced skin penetration in wound healing therapy compared with conventional treatments. Moreover, an improved chemically and physically stable drug delivery system, with increased drug loading capacity and enhanced bioavailability, has been shown in drugs encapsulated in lipid nanoparticles. Their applications in wound care show potential for overcoming impediments, such as the inadequate bioavailability of active agents with low solubility. Future research in nanosized-lipid-based drug delivery systems will allow the achievement of increased bioavailability and better control of drug release, providing the clinician with more effective therapies for wound care.

Characteristics and therapeutic applications of antimicrobial peptides

The demand for novel antimicrobial compounds is rapidly growing due to the phenomenon of antibiotic resistance in bacteria. In response, numerous alternative approaches are being taken including use of polymers, metals, combinatorial approaches, and antimicrobial peptides (AMPs). AMPs are a naturally occurring part of the immune system of all higher organisms and display remarkable broad-spectrum activity and high selectivity for bacterial cells over host cells. However, despite good activity and safety profiles, AMPs have struggled to find success in the clinic. In this review, we outline the fundamental properties of AMPs that make them effective antimicrobials and extend this into three main approaches being used to help AMPs become viable clinical options. These three approaches are the incorporation of non-natural amino acids into the AMP sequence to impart better pharmacological properties, the incorporation of AMPs in hydrogels, and the chemical modification of surfaces with AMPs for device applications. These approaches are being developed to enhance the biocompatibility, stability, and/or bioavailability of AMPs as clinical options.

Prescription, over-the-counter (OTC), herbal, and other treatments and preventive uses for COVID-19

The current COVID-19 pandemic has spread rapidly worldwide and has challenged fragile health care systems, vulnerable socioeconomic conditions, and population risk factors, and has led to an overwhelming tendency to misuse prescription drugs and self-medication with prescription drugs, over-the-counter (OTC) drugs, herbals products, and unproven chemicals as a desperate preventive or curative measure for COVID-19. In this chapter, we present the legislative differences between prescription drugs, OTC drugs, and herbals. Various approved and nonapproved prescription and OTC drugs as symptomatic treatment for COVID-19 are listed and evaluated based on their reported efficacy, safety, and toxicological profile. We also present the various herbal products that are currently studied and used as treatment and preventive for COVID-19. The efficacy, toxicology profile, safety, and legal issues of some speculative preventive and treatment options against COVID-19, such as Miracle Mineral Solution (MMS), chlorine dioxide solution (CDS), colloidal silver, and hydrogen peroxide is presented. The chapter also emphasizes the specific strategies that need to be implemented to guide the population in the effective and safe use of prescribed medications, such as the Medication Therapy Management or Pharmaceutical Care process. Finally, this chapter aims to provide a deeper insight into the lack of health literacy in the population and the effect that drug utilization research (DUR) has in the decision making of health authorities and general public. We aim to provide the current information about the various treatment and preventive options used for COVID-19.

Enhancement of antibacterial property of titanium by two-step micro arc oxidation treatment

A customized micro arc oxidation (MAO) treatment technique was developed to obtain desirable antibacterial properties on titanium surfaces. The two-step MAO treatment was applied to fabricate a specimen containing both Ag and Zn in its surface oxide layer. Surface analyses and metal-ion release tests were performed to evaluate the presence of Ag and Zn and the ion release behavior for simulating practical usage, respectively. Additionally, the antibacterial properties of the specimens were also evaluated using gram-negative facultative anaerobic bacteria. The MAO-treated specimens containing both Ag and Zn showed excellent antibacterial properties against Escherichia coli, and the properties were sustained even after 28 days of immersion in physiological saline to simulate the living environment.

Antibacterial activity of antimicrobial peptide-conjugated nanofibrous membranes

Antimicrobial peptides (AMPs) are considered as novel potential alternatives to antibiotics against increasing number of multi drug resistant (MDR) pathogens. Although AMPs have shown strong antimicrobial activity against gram-negative or gram-positive microorganisms, AMP conjugated biomaterials that are effective against MDR microorganisms are yet to be developed. Herein, the potential use of (RWRWRWRW)-NH2 (AMP-1) and KRFRIRVRV-NH2 (AMP-2) peptide conjugated electrospun polylactic-co-glycolic-acid (PLGA) nanofibers (NFs) fabricated and their antimicrobial effect by themselves and in their dual combination (1:1) were evaluated on P. aeruginosa and methicillin-resistant S. aureus (MRSA). Those AMP conjugated NFs did not inhibit proliferation of keratinocytes. These results suggest that AMP conjugated NF, which has multiple biological activities, would be a promising candidate as a wound dressing material.

Short DNA Oligonucleotide as a Ag+ Binding Detector

Ag⁺ has been known to mediate several natural metallo-base pairs. Based on the unique structural information of a short 8-mer DNA strand (5'-GCACGCGC-3') induced by Ag⁺, we constructed several fluorescent DNA beacons for the detection of Ag⁺ according to the increase in the fluorescence emission on Ag⁺ binding. This Ag⁺ detection assay is quick, sensitive, and easy to adapt and can function in a wide range of temperatures from 5 to 65 °C.

Engineered lactobacilli display anti-biofilm and growth suppressing activities against Pseudomonas aeruginosa

Biofilms are an emerging target for new therapeutics in the effort to address the continued increase in resistance and tolerance to traditional antimicrobials. In particular, the distinct nature of the biofilm growth state often means that traditional antimcirobials, developed to combat planktonic cells, are ineffective. Biofilm treatments are designed to both reduce pathogen load at an infection site and decrease the development of resistance by rendering the embedded organisms more susceptible to treatment at lower antimicrobial concentrations. In this work, we developed a new antimicrobial treatment modality using engineered lactic acid bacteria (LAB). We first characterized the natural capacity of two lactobacilli, L. plantarum and L. rhamnosus, to inhibit P. aeruginosa growth, biofilm formation, and biofilm viability, which we found to be dependent upon the low pH generated during culture of the LAB. We further engineered these LAB to secrete enzymes known to degrade P. aeruginosa biofilms and show that our best performing engineered LAB, secreting a pathogen-derived enzyme (PelAh), degrades up to 85% of P. aeruginosa biofilm.

Green synthesis of antimicrobial silver nanoparticles using aqueous leaf extracts from three Congolese plant species (Brillantaisia patula, Crossopteryx febrifuga and Senna siamea)

In the present study, silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of three Congolese plant species, namely Brillantaisia patula (BR-PA), Crossopteryx febrifuga (CR-FE) and Senna siamea (SE-SI). The obtained AgNPs were studied for their optical, structural, surface morphological and antibacterial properties. The prepared AgNPs were characterized by using UV-Visible spectra, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The synthesized nanoparticles were spherical shaped and well-dispersed with average sizes ranging from 45 to 110 nm. The AgNPs derived from BR-PA, CR-FE and SE-SI exhibited higher antibacterial activity against three bacterial pathogens of the human skin compared to their respective crude extracts and AgNO3. This indicated that the biomolecules covering the nanoparticles may enhance the biological activity of metal nanoparticles. Hence, our results support that biogenic synthesis of AgNPs from Congolese plants constitutes a potential area of interest for the therapeutic management of microbial diseases such as infectious skin diseases.

The impact of continuous electrical microcurrent on acute and hard-to-heal wounds: a systematic review

BACKGROUND

Wound infections result in considerable morbidity, mortality and healthcare costs. Antibiotic resistance has complicated wound healing, and new, non-antibiotic-based treatment methods are being developed.

AIMS

To evaluate evidence on the safety, efficacy and real-world effectiveness of electroceutical devices (ECDs) that provide continuous electrical stimulation to wounds.

METHOD

A systematic search was conducted to identify primary studies published between 2009 and 2019 that described therapeutic wound treatment using portable ECDs. Studies were included if the ECD delivered continuous electrical current directly to the wound area for the duration of treatment.

RESULTS

Of 171 citations identified in the search, 13 articles met the inclusion criteria and were analysed. Nine studies evaluated dressings embedded with zinc and silver particles that generated electricity electrochemically, and four evaluated electrode-based units with external batteries. ECDs were effective in healing complex, hard-to-heal wounds that had not responded to other treatments. Four studies showed that ECDs led to complete closure of wounds without complications, and in some cases healed wounds faster than standard of care (SOC). One study found that ECDs resulted in higher ratings by both patients and surgeons than SOC for the progression of wound healing and scar appearance. Additionally, three studies found ECD treatment was less expensive than SOC, due to patients requiring fewer dressing changes or nurse visits.

CONCLUSION

ECDs appeared to be a safe, effective and cost-effective method for treating severe, complex and challenging wounds, including hard-to-heal wounds, surgical incisions and skin graft donor sites.

Nanomedicine in Healing Chronic Wounds: Opportunities and Challenges

The poor healing associated with chronic wounds affects millions of people worldwide through high mortality rates and associated costs. Chronic wounds present three main problems: First, the absence of a suitable environment to facilitate cell migration, proliferation, and angiogenesis; second, bacterial infection; and third, unbalanced and prolonged inflammation. Unfortunately, current therapeutic approaches have not been able to overcome these main issues and, therefore, have limited clinical success. Over the past decade, incorporating the unique advantages of nanomedicine into wound healing approaches has yielded promising outcomes. Nanomedicine is capable of stimulating various cellular and molecular mechanisms involved in the wound microenvironment via antibacterial, anti-inflammatory, and angiogenetic effects, potentially reversing the wound microenvironment from nonhealing to healing. This review briefly discusses wound healing mechanisms and pathophysiology and then highlights recent findings regarding the opportunities and challenges of using nanomedicine in chronic wound management.