Microbial Diversity of Chronic Wound and Successful Management of Traditional Chinese Medicine

Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment

Introduction

Topical wound treatments rely on carrier formulations with little to no biological impact. The potential for a common vehicle, a propylene glycol (PG) gel, to affect wound healing measures including microbiota is not known. Microbiome characterization, based on next generation sequencing methods is typically performed on tissue or directly obtained wound fluid samples. The utility for primary wound dressings to characterize equine wound microbiota in the context of topical treatments is currently unknown. This investigation reports the topical effect of an 80% PG based gel on wound healing and microbiota in wound dressings.

Methods

Experiments were performed in six mature horses utilizing a surgical, distal limb wound model, histology of sequential wound biopsies, photographic wound measurements and microbiota profiling via 16s rRNA sequencing of wound dressing samples. Experimental wounds were surveyed for 42 days and either treated (Day 7, 14, 21 and 28; at 0.03 ml/cm2) or unexposed to the PG gel. Wound surface area, relative and absolute microbial abundances, diversity indices and histologic parameters were analyzed in the context of the experimental group (treatment; control) using qualitative or quantitative methods depending on data characteristics.

Results

Compared to controls, treatment slowed the wound healing rate (17.17 ± 4.27 vs. 18.56 ± 6.3 mm2/day), delayed the temporal decline of polymorphonucleated cells in wound beds and operational taxonomic units (OTU) in wound dressings and lowered alpha-diversity indices for microbiota in primary wound dressing. Relative abundances of OTUs were in line with those previously reported for equine wounds. Clinical outcomes 42 days post wounding were considered similar irrespective of PG gel exposure.

Discussion

Results highlight the potential for vehicle exposure to alter relevant wound outcome measures, imposing the need for stringent experimental control measures. Primary wound dressings may represent an alternate sample source for characterization of the wound microbiome alleviating the need for additional interventions. Further studies are warranted to contrast the microbiome in wound dressings against that present on wound surfaces to conclude on the validity of this approach.

Research on the wound healing effect of Shengji Huayu Formula ethanol extract-derived fractions in streptozotocin-induced diabetic ulcer rats

BACKGROUND

Diabetic ulcer is a common complication of diabetes. It is characterized by a long-term disease course and high recurrence rate. Shengji Huayu Formula (SHF) is an effective formula for treating diabetic ulcers. However, the specific effective parts of SHF remain unclear. Clarifying the active polar site of SHF would be helpful to refine research on the components in SHF that promote wound healing. This research aims to focus on evaluating the activity of polar fractions.

METHODS

A diabetic rat model was established by intraperitoneally injecting streptozotocin (STZ) and was adopted to confirm the therapeutic effect of SHF. Four different polarity parts were extracted from SHF and prepared into a cream to evaluate the activity. High-performance liquid chromatography (HPLC) was used to detect chemical constituents in chloroform extracts.

RESULTS

It was discovered that dracorhodin, aloe-emodin, rhein, imperatorin, emodin, isoimperatorin, chrysophanol, physcion, and tanshinone IIA were the main components of the chloroform extract from SHF. The results revealed that chloroform extract could effectively accelerate diabetic wound healing by promoting collagen regeneration and epidermal repair. Chloroform extract of SHF could stimulate the generation of vascular endothelial growth factor (VEGF). The results are also indicated that the effective active fraction was the chloroform part, and the method of detecting the main chemical constituents in the active part was successfully established.

CONCLUSION

SHF could improve diabetic ulcers by promoting granulation tissue synthesis. In this study, four polar parts (petroleum ether, chloroform, ethylacetate, n-butanol) were extracted from a 95% ethanol extract. In contrast, chloroform polar parts showed a higher wound closure rate, stimulated more collagen regeneration and promoted more production of vascular endothelial cells. In conclusion, the chloroform extract of SHF was the effective polar part in ameliorating diabetic wound healing.

Dual Action Gels Containing DsiRNA Loaded Gold Nanoparticles: Augmenting Diabetic Wound Healing by Promoting Angiogenesis and Inhibiting Infection

Hyperglycemia induces the prostaglandin transporter (PGT) gene overexpression, leading to poor vascularization and wound healing. Dicer substrate small interfering RNA (DsiRNA) and gold nanoparticles (AuNPs) co-loaded into PF127 gel was developed to overcome the disturbance and infections. The AuNPs were biosynthesized using cold and hot water extracts of Lignosus rhinocerotis (abbreviated CLRE and HLRE, respectively). The wound healing efficacy of a PF127 gel containing DsiRNA-AuNPs-CLRE and -HLRE (assigned as F2 and F3, respectively) was evaluated in a diabetes-induced Wistar rat model. The F2 (DC) and F3 (DH) treated groups revealed a faster wound closure (92.67 ± 3.4% and 85.1 ± 7.3%, respectively) than the positive control (commercial gel, DTI)(74.9 ± 13.3%). DH and DC groups presented an increased blood vessel density, along with decreased inflammatory cells. In comparison to positive control, higher prostaglandin E₂ (PGE₂) (495 ±79 and 50 ±121 pg/mL, for DC and DH group, respectively), vascular endothelial growth factor (VEGF) (49 ±15 and 38 ±3 pg/mL, for DC and DH group, respectively) and VEGF-A levels were detected in both groups (DC and DH), indicating the effectiveness of DsiRNA in enhancing PGE₂ production and vascularization. On evaluating microbiomes adhered to the wound areas, Gram-positive bacteria Staphylococcus and Corynebacterium, as well as Gram-negative Pseudomonas, Rodentibacter, and Acinetobacter, were found to be sensitive to the gel. Collectively, the gel was confirmed as a promising dressing for diabetic wound therapy, warranting further studies for clinical use.

ZnO Nanoparticles-Modified Dressings to Inhibit Wound Pathogens

Zinc oxide (ZnO) nanoparticles (NPs) have been investigated for various skin therapies in recent years. These NPs can improve the healing and modulate inflammation in the wounds, but the mechanisms involved in such changes are yet to be known. In this study, we have designed a facile ZnO nano-coated dressing with improved antimicrobial efficiency against typical wound pathogens involved in biofilm and chronic infections. ZnO NPs were obtained by hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Antibacterial and antibiofilm effects were evaluated against laboratory and clinical isolates of significant Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) opportunistic pathogens, by quantitative methods. Our results have shown that the developed dressings have a high antibacterial efficiency after 6–24 h of contact when containing 0.6 and 0.9% ZnO NPs and this effect is similar against reference and clinical isolates. Moreover, biofilm development is significantly impaired for up to three days of contact, depending on the NPs load and microbial species. These results show that ZnO-coated dressings prevent biofilm development of main wound pathogens and represent efficient candidates for developing bioactive dressings to fight chronic wounds.

The Ambivalent Role of Skin Microbiota and Adrenaline in Wound Healing and the Interplay between Them

After skin injury, wound healing sets into motion a dynamic process to repair and replace devitalized tissues. The healing process can be divided into four overlapping phases: hemostasis, inflammation, proliferation, and maturation. Skin microbiota has been reported to participate in orchestrating the wound healing both in negative and positive ways. Many studies reported that skin microbiota can impose negative and positive effects on the wound. Recent findings have shown that many bacterial species on human skin are able to convert aromatic amino acids into so-called trace amines (TAs) and convert corresponding precursors into dopamine and serotonin, which are all released into the environment. As a stress reaction, wounded epithelial cells release the hormone adrenaline (epinephrine), which activates the β2-adrenergic receptor (β2-AR), impairing the migration ability of keratinocytes and thus re-epithelization. This is where TAs come into play, as they act as antagonists of β2-AR and thus attenuate the effects of adrenaline. The result is that not only TAs but also TA-producing skin bacteria accelerate wound healing. Adrenergic receptors (ARs) play a key role in many physiological and disease-related processes and are expressed in numerous cell types. In this review, we describe the role of ARs in relation to wound healing in keratinocytes, immune cells, fibroblasts, and blood vessels and the possible role of the skin microbiota in wound healing.

Factors related to the composition and diversity of wound microbiota investigated using culture-independent molecular methods: a scoping review

All open wounds are often colonized by commensal microbes as a loss of skin can provide a ready portal of entry for microorganisms. Although the wound microbiota is known to be associated with wound infection and with delayed healing, the factors related to the formations of wound microbiota contributing to such poor clinical outcomes are not clear and have not led to effective infection prevention interventions. This review aimed to scope the factors related to the composition and diversity of wound microbiota that have been investigated using culture-independent molecular methods. Original articles on wound microbiota published from January 1986 to February 2020 were included in this review. Thirty-one articles met the inclusion criteria and were grouped according to wound types: chronic, acute, and animal model wounds. The factors identified were categorized according to patient characteristics, wound characteristics, treatment, and sampling. Although some studies reported the effect size of the factors, the values were small. No studies elucidated the mechanism of wound microbiota formation. The results of this scoping review highlight that the factors associated with the diversity of wound microbiota are poorly understood and that further studies are needed.

Effects of cefazolin-containing niosome nanoparticles against methicillin-resistant Staphylococcus aureus biofilm formed on chronic wounds

The ability of biofilm formation in methicillin-resistant Staphylococcus aureus (MRSA) causes significant mortality and morbidity in wound infections. Nanoparticles because of the drug concentration increment at the point of contact of nanoparticles and bacteria, and slower release of the drug at the desired location are considered as proper tools to overcome the therapeutic problem of antimicrobial-resistant infections. This study was aimed to evaluate the anti-biofilm activity of cefazolin-loaded nanoparticles against MRSA isolates. The 27 clinical isolates of MRSA were collected from patients with pressure sores and diabetic ulcers referred to Loghman Hospital in Tehran-Iran. MRSA isolates were detected by polymerase chain reaction (PCR) and biochemical tests. Cefazolin-loaded niosome was synthesized using the thin-film hydration method and were characterized by zeta potential measurement and transmission electron microscopy (TEM). The round-shaped cefazolin-loaded niosomes had a diameter of 100 nm and a -63 mV zeta potential. The cefazolin-containing niosomes removed 1, 3, and 5 d old biofilms at the concentration of 128 µg ml-1, 128 µg ml-1, and 256 µg ml-1, respectively. Histological results indicated that BALB/c mice receiving cefazolin-loaded niosomes were treated effectively faster than those treated by cefazolin or untreated group. In conclusion, the cefazolin-loaded niosome could be considered as a promising candidate for the treatment of biofilm-mediated infections of MRSA.

An Efficacy Predictive Method for Diabetic Ulcers Based on Higher-Order Markov Chain-Set Pair Analysis

Background

Clinical comprehensive decision-making of diabetic ulcers includes curative effect evaluation and curative effect prediction. Nevertheless, there are few studies on the prediction of diabetic ulcers.

Methods

Set pair analysis (SPA) was used to assess the curative effect evaluation, and therapeutic effect was evaluated by connection degree (CD). The higher-order Markov chain-SPA curative effect prediction model was established to predict the future curative effect development. The predicted results with higher-order Markov chain-SPA and traditional first-order Markov-SPA model were compared with the actual results of the patients to verify the effectiveness of prediction.

Results

The connection degree of index levels I and II of 15 patients with diabetic ulcers after traditional Chinese medicine (TCM) treatment increased with time, while that of index levels IV and V decreased, indicating that the curative effect tends to improve. The higher-order Markov chain-SPA model was used to predict the curative effect. The results showed that the relative errors were fewer than the traditional first-order Markov-SPA model.

Conclusions

The present study suggests that a method of SPA combined with higher-order Markov-SPA is relatively effective and can be applied to the clinical prediction of diabetic ulcers, which has higher accuracy than traditional first-order curative effect prediction model.

The crude ethanol extract of Periplaneta americana L. stimulates wound healing in vitro & in vivo

Periplaneta americana L. is a Traditional Chinese Medicine that has been used in clinic treatment of various diseases for a long history. However, the therapeutic potential and the underlying mechanism of Periplaneta americana L. in the skin wound therapy was not investigated comprehensively yet. This study aims to investigate the influence of the crude ethanol extract of PAL in the different wound stages including: (1) the migration and chemotaxis to skin cells in the first stage; (2) proliferation and cells cycle of skin cells in the second stage; (3) remodeling effect and secretion of growth factors, collagens in the third stage; (4) as well as the influence in the blood vessels regeneration in the late stage. The crude ethanol extract of PAL was shown to (1) promote the keratinocytes proliferation and regulate the cells cycle of fibroblasts significantly; (2) stimulate the migration of keratinocytes and fibroblasts obviously; (3) enhance the EGF and VEGF secretion both in vitro & in vivo; (4) accelerate the wound healing, collagen synthesis and angiogenesis. The crude ethanol extract of KFX was shown a promising therapeutic agent for the wound therapy with great efficacy to accelerate the wound healing with improved quality.

Application of a Cloud Model-Set Pair Analysis in Efficacy Assessment for Diabetic Ulcers

Because treatment of diabetic ulcers includes various uncertainties, efficacy assessments are needed and significant. In previous studies, set pair analysis (SPA) has been applied to the efficacy assessments of traditional Chinese medicine (TCM) that pick out uncertainties related to the development and prognosis of disease. Optimized clinical protocols of SPA improve clinical efficacy. In the article, cloud model (CM) is employed to improve SPA, and a novel efficacy assessment method for a treatment of diabetic ulcers is proposed based on the cloud model-set pair analysis (CM-SPA). It is recommended to replace connection degree (CD) with cloud connection degree (CCD) that the efficacy assessment results are shown as normal clouds. Then, three diabetic ulcers patients treated with TCM made importance assessment by both CM-SPA and AHP based SPA. The comparison of assessment results shows that the CM-SPA is efficacious for the efficacy assessment of a treatment for diabetic ulcers and the results will be more scientific and accurate via CM-SPA.