Antimicrobial and anti-biofilm potencies of dermcidin-derived peptide DCD-1L against Acinetobacter baumannii: an in vivo wound healing model

Background The global emergence of Acinetobacter baumannii resistance to most conventional antibiotics presents a major therapeutic challenge and necessitates the discovery of new antibacterial agents. The purpose of this study was to investigate in vitro and in vivo anti-biofilm potency of dermcidin-1L (DCD-1L) against extensively drug-resistant (XDR)-, pandrug-resistant (PDR)-, and ATCC19606-A. baumannii. Methods After determination of minimum inhibitory concentration (MIC) of DCD-1L, in vitro anti-adhesive and anti-biofilm activities of DCD-1L were evaluated. Cytotoxicity, hemolytic activity, and the effect of DCD-1L treatment on the expression of various biofilm-associated genes were determined. The inhibitory effect of DCD-1L on biofilm formation in the model of catheter-associated infection, as well as, histopathological examination of the burn wound sites of mice treated with DCD-1L were assessed. Results The bacterial adhesion and biofilm formation in all A. baumannii isolates were inhibited at 2 × , 4 × , and 8 × MIC of DCD-1L, while only 8 × MIC of DCD-1L was able to destroy the pre-formed biofilm in vitro. Also, reduce the expression of genes involved in biofilm formation was observed following DCD-1L treatment. DCD-1L without cytotoxic and hemolytic activities significantly reduced the biofilm formation in the model of catheter-associated infection. In vivo results showed that the count of A. baumannii in infected wounds was significantly decreased and the promotion in wound healing by the acceleration of skin re-epithelialization in mice was observed following treatment with 8 × MIC of DCD-1L. Conclusions Results of this study demonstrated that DCD-1L can inhibit bacterial attachment and biofilm formation and prevent the onset of infection. Taking these properties together, DCD-1L appears as a promising candidate for antimicrobial and anti-biofilm drug development.

Impact of Virtual Reality Technology on Pain and Anxiety in Pediatric Burn Patients: A Systematic Review and Meta-Analysis

Introduction: Virtual reality (VR) has the potential to lessen pain and anxiety experienced by pediatric patients undergoing burn wound care procedures. Population-specific variables require novel technological application and thus, a systematic review among studies on its impact is warranted.Objective: The objective of this review was to evaluate the effectiveness of VR on pain in children with burn injuries undergoing wound care procedures.Methods: A systematic literature review was performed using PubMed and CINAHL databases from January 2010 to July 2021 with the keywords “pediatric,” “burn,” “virtual reality,” and “pain.” We included experimental studies of between- and within-subjects designs in which pediatric patients’ exposure to virtual reality technology during burn wound care functioned as the intervention of interest. Two researchers independently performed the literature search, made judgements of inclusion/exclusion based on agreed-upon criteria, abstracted data, and assessed quality of evidence using a standardized appraisal tool. A meta-analysis was conducted to evaluate the effectiveness of the VR on burning procedural pain in pediatric population. Standardized mean difference (SMD) was used as an index of combined effect size, and a random effect model was used for meta-analysis.Results: Ten articles published between January 2010 and July 2021 passed the selection criteria: six randomized controlled trials and four randomized repeated-measures studies. Consistent results among the studies provided support for VR as effective in reducing pain and potentially pain related anxiety in children undergoing burn wound care through preprocedural preparation (n = 2) and procedural intervention (n = 8). A random effects meta-analysis model indicated a moderate and significant combined effect size (SMD = 0.60, 95% CI = 0.28–0.93, p = 0.0031) of VR effects on pain intensity ratings with no significant heterogeneity of VR intervention effects between studies. Only one study reported direct influence of VR intervention on pre-procedural situational anxiety with a moderate effect size (Cohen’s d = 0.575, 95%CI = 0.11–1.04).Conclusion: Children’s exposure to VR during burn care procedures was associated with lower levels of pain and pain related anxiety. Moderate to large effect sizes support the integration of VR into traditional pediatric burn pain protocols irrespective of innovative delivery methods and content required for use in burned pediatric patients.

Preparation of Silver Ion Antimicrobial Dressings and Prevention and Treatment of Central Venous Catheter-Related Infection on Burn Wounds of Critically Burned Patients

To further understand the characteristics of Ag+ antimicrobial dressings and its application value in the prevention and treatment of infections in burn patients, in the study, the Ag+ gel dressings were prepared and their physical and chemical characteristics were analyzed, and relationship between the gel dressing and central venous catheter (CVC)-related infections was further explored. The results showed that silver nitrate was made into nano silver particles, and its structure was clearly visible under microscope, and nano silver was further applied to preparation of Ag+ antibacterial dressings. Fibrocytes were clearly visible in Ag+ gel dressing and arranged uniformly, which indicated that Ag+ gel dressing had good compatibility with biological materials and had no obvious toxicity. Further clinical trials showed that Ag+ gel dressing can effectively reduce CVC-related infections. From 1 to 4 weeks of the experiment, the bacterial infection rate in burn wounds and blood of the treatment group (TG), which applied Ag+ gel dressing, was lower than the control group (P < 0.05). During the treatment, the burn healing rate of the TG was also greatly higher than the control group (P < 0.05). In addition, the burn wound exudate in the TG was greatly less than the control group (P < 0.05). In summary, the Ag+ gel dressing prepared has good biological and physical and chemical properties, which have bright prospects in the prevention and treatment of burn wounds and CVC-related infections. This study provides an experimental basis for clinical application of Ag+ gel dressing.

The Superior Outcome of Collagen Nanosilver in Increasing Macrophage and Collagen on Deep Dermal Burn Wound Healing

AIM: This study aims to prove the superior outcome of collagen nanosilver in increasing macrophage and collagen on deep dermal burn wound healing. METHODS: This study was a randomized control trial design. All animals used were male Sprague Dawley rats aged 12–14 weeks old and weighed about 200–250 g. Each rat gets four site injuries and is given treatments. The treatment group includes: I (negative control using NaCl 0.9%), II (positive control using silver sulfadiazine cream), III (treatment with nanosilver collagen cream 1%), and IV (treatment with collagen nanosilver cream 2%). Macrophages counts were assessed using IHC F40/80 and collagen density was assessed using Masson’s trichrome staining. RESULTS: Macrophage on day 6 showed a significant difference as seen in group III and group IV. A significant difference was also obtained between macrophage on day 3 and day 6 from group IV, likewise between collagen between day 3 and day 6 from group III and IV. Collagen nanosilver acts as an antimicrobial and anti-inflammatory agent by increasing the mechanism of activation and migration of macrophages to the site of injury. Moreover, this formula modulated the collagen deposition, which forms the tissue fibers which ultimately provide a conducive environment for wound healing. CONCLUSION: Collagen nanosilver has a superior outcome in the increasing macrophage cell count and collagen density of deep dermal burn wound healing.

Recent advances in terahertz imaging: 1999 to 2021

We discuss the progress in the field of THz imaging based on time-domain spectroscopy during the last 20 years emphasizing several highlights. These include 3D mapping of the water distribution of plants, THz reflection imaging of samples with arbitrary shape, burn wound imaging and the early diagnosis of diabetic foot disease. These applications greatly benefit from the introduction of fibre-coupled THz time-domain system operated by rugged and portable femtosecond fibre-lasers. THz imaging is a versatile measurement method that has a plethora of practical applications and great promise for the future.

Development and Optimization of Acriflavine-Loaded Polycaprolactone Nanoparticles Using Box–Behnken Design for Burn Wound Healing Applications

Nanoparticles are used increasingly for the treatment of different disorders, including burn wounds of the skin, due to their important role in wound healing. In this study, acriflavine-loaded poly (ε-caprolactone) nanoparticles (ACR-PCL-NPs) were prepared using a double-emulsion solvent evaporation method. All the formulations were prepared and optimized by using a Box–Behnken design. Formulations were evaluated for the effect of independent variables, i.e., poly (ε-caprolactone) (PCL) amount (X1), stirring speed of external phase (X2), and polyvinyl alcohol (PVA) concentration (X3), on the formulation-dependent variables (particle size, polydispersity index (PDI), and encapsulation efficiency) of ACR-PCL-NPs. The zeta potential, PDI, particle size, and encapsulation efficiency of optimized ACR-PCL-NPs were found to be −3.98 ± 1.58 mV, 0.270 ± 0.19, 469.2 ± 5.6 nm, and 71.9 ± 5.32%, respectively. The independent variables were found to be in excellent correlation with the dependent variables. The release of acriflavine from optimized ACR-PCL-NPs was in biphasic style with the initial burst release, followed by a slow release for up to 24 h of the in vitro study. Morphological studies of optimized ACR-PCL-NPs revealed the smooth surfaces and spherical shapes of the particles. Thermal and FTIR analyses revealed the drug–polymer compatibility of ACR-PCL-NPs. The drug-treated group showed significant re-epithelialization, as compared to the controlled group.