Accelerative effects of alginate-chitosan/titanium oxide@geraniol nanosphere hydrogels on the healing process of wounds infected with Acinetobacter baumannii and Streptococcus pyogenes bacteria

This study was conducted to evaluate the effects of alginate-chitosan/titanium oxide/geraniol (Alg-Csn/TiO2@GRL nanosphere) nanospheres hydrogels on the healing process of the wounds infected with Acinetobacter baumannii and Streptococcus pyogenes bacteria. The nanospheres were successfully synthesized and their physicochemical properties such as DLS, FTIR, FE-SEM, TEM, XRD and also their safety and in-vitro antibacterial activity were assessed and confirmed. Following induction of the infected wounds, the mice were treated with s base ointment (Control), mupirocin® as standard control group and also hydrogels prepared from Alg-Csn@GRL, Alg-Csn/TiO2 and Alg-Csn/TiO2@GRL. Wound contraction, total bacterial count, expression of bFGF, VEGF, IGF-1, CD68 and COL-1 A, iNOS and eNOS were measured. The results showed the treatment of wounds with Alg-Csn/TiO2@GRL hydrogels significantly accelerated wound contraction, decreased total bacterial count and reduced the expressions of CD68, iNOS and eNOS and increased the expressions of VEGF, bFGF, IGF-1 and COL-1 A compared with other groups. It can be concluded that Alg-Csn/TiO2@GRL hydrogels expedite the wound healing process by their effects on bacteria and subsequently inflammation and increasing the expression of proliferative genes. The Alg-Csn/TiO2@GRL hydrogel can be utilized in combination with other agents for the treatment of infected wounds after future clinical studies.

Natural self-healing injectable hydrogels loaded with exosomes and berberine for infected wound healing

Complete and rapid healing of infected skin wounds remains a challenge in current clinical treatment. In this study, we prepared a self-healing injectable CK hydrogel by crosslinking two natural polysaccharides, carboxymethyl chitosan and oxidized konjac glucomannan, based on the Schiff base bond. To enhance the biological function of the hydrogel, we multi-functionalized hydrogen by loading it with berberine (BBR) and stem cell-derived exosomes (Exo), forming a composite hydrogel, CK@BBR&Exo, which could be injected directly into the wound through a needle and adhered to the wound. Furthermore, the self-healing properties of CK@BBR&Exo increased its usefulness and service life. Additionally, the drug-loaded CK@BBR&Exo hydrogel was versatile, inhibiting bacterial growth, regulating the inflammatory response, and promoting neovascularization in infected skin wounds, thus achieving the rapid healing of infected skin wounds. These results suggest that the CK@BBR&Exo-injectable self-healing hydrogel is an ideal dressing for treating infected skin wounds.

Acceleration in healing of infected full-thickness wound with novel antibacterial γ-AlOOH-based nanocomposites

This study was conducted to synthesize γ-AlOOH (bohemite)-based nanocomposites (NCs) of Au/γ-AlOOH-NC and its functionalized derivative using chitosan (Au/γ-AlOOH/Ctn-NC) and with the help of one-step Mentha piperita. The physicochemical characteristics of the NCs were investigated. In addition, biomedical properties, such as antibacterial activity under in vitro and in vivo conditions, and cell viability were assessed. Wound healing activity on infected wounds and histological parameters were assessed. The gene expressions of TNF-α, Capase 3, Bcl-2, Cyclin-D1 and FGF-2 were investigated. The TEM and FESEM images showed the sheet-like structure for bohemite in Au/γ-AlOOH-NC with Au nanoparticles in a range of 14-15 nm. The elemental analysis revealed the presence of carbon, oxygen, aluminum, and Au elements in the as-synthesized Au/γ-AlOOH. The results for toxicity showed that the produced nanocomposites did not show any cytotoxicity. Biomedical studies confirmed that Au/γ-AlOOH-NC and Au/γ-AlOOH/Ctn-NC have anti-bacterial properties and could expedite the wound healing process in infected wounds by an increase in collagen biosynthesis. The administration of ointment containing Au/γ-AlOOH-NC and Au/γ-AlOOH/Ctn-NC decreased the expressions of TNF-α, and increased the expressions of Capase 3, Bcl-2, Cyclin-D1 and FGF-2. The novelty of this study was that bohemite and Au nanoparticles can be used as a dressing to accelerate the wound healing process. In green synthesis of Au/γ-AlOOH-NC, phytochemical compounds of the plant extract are appropriate reagents for stabilization and the production of Au/γ-AlOOH-NC. Therefore, the new bohemite-based NCs can be considered as candidate for treatment of infected wounds after future clinical studies.

Potential of stem cells for treating infected Diabetic Foot Wounds and Ulcers: a systematic review

Infected diabetic foot ulcers (iDFUs) cause great concern, as they generally heal poorly and are precursive of diabetic-related foot amputation and even death. Scientists have tested various techniques in attempts to ascertain the best treatment for iDFUs; however, the results have remained inconclusive. Stem cell therapy (SCT) appears to improve iDFU through its antimicrobial impacts, yet cogent information regarding the repair of iDFUs with SCT is lacking. Herein, published articles are evaluated to report coherent information about the antimicrobial effects of SCT on the repair of iDFUs in diabetic animals and humans. In this systematic review, we searched the Scopus, Medline, Google Scholar, and Web of Science databases for relevant full-text English language articles published from 2000 to 2022 that described stem cell antimicrobial treatments, infected diabetic wounds, or ulcers. Ultimately, six preclinical and five clinical studies pertaining to the effectiveness of SCT on healing infected diabetic wounds or ulcers were selected. Some of the human studies confirmed that SCT is a promising therapy for diabetic wounds and ulcers. Notably, more controlled studies performed on animal models revealed that stem cells combined with a biostimulator such as photobiomodulation decreased colony forming units and hastened healing in infected diabetic wounds. Moreover, stem cells alone had lower therapeutic impact than when combined with a biostimulant.

Comparison effects of platelet-rich plasma on healing of infected and non-infected excision wounds by the modulation of the expression of inflammatory mediators: experimental research

INTRODUCTION

Microbial invasion in soft tissue is believed to cause infectious wounds and increase healthcare costs, anxiety, and distress. The current study was conducted to evaluate the effects of topical use of platelet-rich plasma (PRP) on infected wound-healing process in rats.

METHODS

Following the induction of a circular wound, the animals were divided into three groups, including (1) standard control: infected wounds treated with mupirocin (SDCL), (2) non-infected wounds treated with PRP (PRP), and (3) infected group in which the rats were infected with Staphylococcus epidermidis and Pseudomonas aeruginosa and treated with PRP (INF + PRP). To evaluate the effects of PRP on the wound-healing rate, total bacterial count, histopathological assessment, the serum concentrations of sialic acid, C-reactive protein, haptoglobin, and fibrinogen were assessed. Additionally, IL-1β, IL-6, TNF-α, IL-3, NF-κB, iNOS, PDGF, and EGF mRNA level expressions were assessed employing the qRT-PCR method.

RESULTS

The results indicated that topical application of PRP could significantly decrease total bacterial count, the level of C-reactive protein, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) compared to the SDCL group. The administration of PRP also promoted re-epithelization rate by increasing the expression of EGF mRNA level.

CONCLUSION

We could recommend the use of PRP for the treatment of infected wounds owing to its efficiency in decreasing colonization of tissue bacteria, tissue inflammation, and stimulating wound heal-up.

Treatment of infected wounds with methylene blue photodynamic therapy: An effective and safe treatment method

BACKGROUND

Bacterial resistance is a problem during the process of healing of infected wounds. As a therapy, photodynamic therapy (PDT) has broad-spectral antibacterial activity and non-selective action, which makes it possible to deal with antibiotic resistance.. Methylene blue is a commonly used medicine, but it is rarely used in clinical practice as a photosensitizer. The effect of methylene blue photodynamic therapy (MB-PDT) on infected wounds remains unclear. Our study aims to evaluate the safety and efficacy of MB-PDT on infected wounds.

METHODS

In this study, 5 patients with infected wounds were included, all of them were treated with MB-PDT by using the red LED which irradiated the wounds directly (635 nm, 120 J/cm2, 100 mW/cm2). The frequency and course of treatment were determined by the severity of the wound.

RESULTS

After an average of 4 PDT session, infected wounds of all the patients healed.. The treatment also showed an excellent cosmetic effect. According to the follow-up periods of patients ranged from 3 to 12 months, there were no recurrences and side effects.

CONCLUSIONS

MB-PDT has a great healing effect on infected wounds, and it is a safe, cheap and active clinical therapy.

"Low cost, modified negative pressure wound therapy in infected orthopaedic wounds: can it be as effective as its costly counterparts?"

BACKGROUND

Infected wounds pose a great financial burden on our healthcare system. Negative pressure wound therapy (NPWT) has brought a paradigm shift in the management of these wounds. However, availability and high cost of a conventional NPWT system remains a challenge. We carried out this study to assess whether we can replicate functioning of the conventional NPWT system using resources which are easily available in most hospitals and determine the clinical efficacy and cost effectiveness of the same.

MATERIAL AND METHODS

A prospective study was conducted in the orthopaedic department at our tertiary care institute from January 2018 to December 2019. Fifty six patients with contaminated or infected orthopaedic wounds were included in the study. Wound dressings were carried out by modified negative pressure therapy and their results were studied.

RESULTS

The study group consisted of 41 males and 15 females. Duration of stay in hospital ranged from 6 to 37 days, with average duration of 14.05 days. Wound closure was achieved by secondary suturing in 18 (32.2%) of the cases and split thickness skin grafting in 38 (67.8%) of the cases. Wound assessment done using the revised Photographic wound assessment tool revealed an average of 60% reduction in scores, post procedure. The average cost of the dressing could be considerably reduced during the study by the use of available material.

CONCLUSION

Through our study we describe a simple and effective method of application of negative pressure dressings which may be beneficial in low resource settings. Our method is easily reproducible and does not require expertise for its application, at the same time it is cost effective and efficient in wound care.

Preformulation studies on novel garvicin KS peptides for topical applications

Antimicrobial peptides (AMPs) are emerging as a viable alternative to antibiotics attributable to their potent antimicrobial effects and low propensity for resistance development, especially in chronic infected wounds. The development of an optimized topical formulation of AMPs is thus warranted. Preformulation studies for determination of the suitability and optimization requirements of AMPs in topical formulation development are important. Therefore, we sought to investigate the preformulation studies for a novel bacteriocin garvicin KS (GarKS), which is composed of three peptides (GakA, GakB, and GakC). The effects of physiological fluids and varying temperatures on GarKS peptide stability were determined. The antimicrobial effects of the peptides and their combinations were evaluated in Staphylococcus aureus (methicillin sensitive and resistant strains). Furthermore, their effects on fibroblast viability and proliferation were determined. The GarKS peptides were stable in water and PBS at room and physiological temperatures, however, the peptides were significantly degraded in simulated wound fluid. The antimicrobial and fibroblast cell viability/proliferation effects of either individual GarKS peptides or their combinations varied. A careful consideration of the peptide stability, antimicrobial efficacy, and fibroblast viability/proliferation effects suggests GakA+GakB as a potent combination for the development of an optimized topical formulation of GarKS peptides.

Topical delivery of growth factors and metal/metal oxide nanoparticles to infected wounds by polymeric nanoparticles: an overview

INTRODUCTION

Infected chronic wounds particularly diabetic foot ulcers (DFUs) can result from stable colonization of antibiotic-resistant bacteria and fungi at the wound sites. In this context, the rapid healing of infected wounds has been the main goal in recent investigations. This issue can be solved by improving wound-healing phases including hemostasis, inflammatory, proliferative, and remodeling/maturation, and removal of bacteria and fungi. The applications of growth factors (GFs) and metal/metal oxide nanoparticles (MNPs/MONPs) are two choices for these targets. However, the lack of sustainable release of these agents is an important problem for appropriate wound healing.

AREA COVERED

The present review is focused on recent advances in delivery systems composed of growth factor and MNPs/MONPs for rapid wound healing.

EXPERT OPINION

Synthetic and natural polymeric micro- and nanocarriers including polyvinylpyrrolidone (PVP) and chitosan play a vital role in the healing of infected chronic wounds. Using various derivatives of chitosan as pH-responsive polymer with basic and acidic groups can be the best option to prepare controllable and sequential GF release. However, it warrants further extensive research to solve wound-healing problems.

Nitrogen-doped carbon quantum dots as an antimicrobial agent against Staphylococcus for the treatment of infected wounds

Antimicrobial resistance is becoming more and more serious and has become a potential hazard to human life and health. The fabrication of some new antibacterial substances against resistant bacteria is demanded. With the wide application and research of carbon nanomaterials, nitrogen-doped carbon quantum dots (NCQDs) were synthesized by a one-step chemical route herein. The particle size of NCQDs in the range of 2-5 nm were characterized by transmission electron microscopy (TEM), atomic force microscopy, and dynamic light scattering. The functional groups and optical properties of NCQDs were investigated by UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Disk-diffusion tests showed that the NCQDs had specific antibacterial activity against Staphylococcus. TEM showed that the NCQDs could destroy the cell structure of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) but could not combat Escherichia coli. The antibacterial mechanism may be that positively charged NCQDs firstly interacted with the negatively charged bacteria, and then specifically anchored on some specific sites on the surface of Staphylococcus. The NCQDs were applied to treat wounds infected with MRSA and showed the same therapeutic effect as vancomycin. Photomicrographs of hematoxylin-eosin-stained histological sections showed that the NCQDs at concentrations effectively killing S. aureus and MRSA caused negligible toxicity to the main rat organs, including heart, liver, spleen, lung, and kidney. Thus, the NCQDs can be developed as a promising antibacterial agent for Staphylococcus. And the NCQDs are likely to treat local infections caused by Staphylococcus clinically, especially S. aureus and MRSA.

Impact of infection severity on clinical outcomes in critical limb ischemia with tissue loss after endovascular treatment

Critical limb ischemia with infected wounds is known to have a poor prognosis and evaluation of infection severity using the Wound, Ischemia, and foot Infection classification system has been recommended. However, little is known about how infection severity influences the clinical outcomes of critical limb ischemia in patients with tissue loss. We investigated the impact of infection severity on the clinical outcomes in critical limb ischemia with tissue loss after endovascular treatment. In April 2007-August 2014, we enrolled 263 patients (328 limbs) who received endovascular treatment for critical limb ischemia with tissue loss. In the limbs examined, 369 individual wounds existed. We evaluated wound infection using the Infectious Disease Society of America (IDSA) classification. We also investigated wound healing rates at 12 months and limb salvage and major amputation-free survival rates at 2 years after endovascular treatment. Wound healing rates at 12 months for class 0, 1, 2, and 3 were 89, 81, 58, and 33%, respectively (log rank P < 0.001). Limb salvage and major amputation-free survival rates at 2 years were lower in patients with lower vs. higher IDSA classes (classes 0-3: limb salvage rate: 97, 90, 61, and 0%, respectively; P < 0.001; major amputation-free survival: 67, 61, 38, and 0%, respectively; P < 0.001). In Rutherford category 5, only wound healing rates at 12 months and limb salvage and major amputation-free survival rates at 2 years were stratified according to wound infection severity (wound healing rates: 87% in classes 0 and 1 and 65% in classes 2 and 3; P < 0.001; limb salvage rates: 93% in classes 0 and 1 and 69% in classes 0 and 2; P < 0.0001; major amputation-free survival rates: 61% in classes 0 and 1 and 46% in classes 2 and 3; P < 0.001). Wound infection severity affects clinical outcomes of critical limb ischemia with tissue loss, especially in critical limb ischemia with systemic inflammatory response syndrome. In Rutherford category 5, only clinical outcomes of critical limb ischemia were well-stratified according to infection severity. Wound infection affects clinical outcomes of patients with critical limb ischemia with tissue loss.

Platelet-rich plasma as an additional therapeutic option for infected wounds with multi-drug resistant bacteria: in vitro antibacterial activity study

PURPOSE

Infected wounds, such as diabetic foot infections, are mostly polymicrobial and microorganisms have high resistance rates to antimicrobials. Infected wounds in diabetic patients have high cost, morbidity, and mortality rates. Based on these facts, there is a need for supportive localized treatment options such as platelet-rich plasma (PRP) implementations. Demonstrating the in vitro antimicrobial effect, our aim was to lead up to clinical trials of localized PRP implementations in infected wounds such as diabetic foot infections. In this study, we aimed to demonstrate the in vitro antibacterial activity of PRP against methicilin-resistant Staphylococcus aureus (MRSA) and three more multi-drug resistant bacteria species that are important and hard-to-treat in wound infections.

MATERIALS AND METHODS

In vitro antimicrobial activity of autologous PRP, platelet-poor plasma (PPP), and phosphate-buffered saline (PBS) on methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., extended spectrum beta lactamase producing Klebsiella pneumoniae, and carbapenem-resistant Pseudomonas aeruginosa was compared by assessment of bacterial growth on agar plates and antimicrobial susceptibility test results.

RESULTS

When compared to control group, PRP and PPP significantly suppressed bacterial growth of MRSA, K. pneumoniae, and P. aeruginosa at 1st, 2nd, 5th, and 10th hours of incubation (p < 0.05). VRE was the only bacteria that PRP and PPP showed limited activity against. When compared to PPP, PRP showed higher activity against MRSA, K. pneumoniae, and P. aeruginosa. However, the differences between PRP and PPP were statistically significant only against MRSA and P. aeruginosa at the first hour of incubation.

CONCLUSIONS

Emerging PRP and other platelet-derived products seem to be promising alternative tools besides antibiotic treatment, debridement, negative pressure wound therapy, hyperbaric oxygen therapy, and other treatment options for treating diabetic foot infections.

Tunable sequential drug delivery system based on chitosan/hyaluronic acid hydrogels and PLGA microspheres for management of non-healing infected wounds

Treatment of non-healing infected wounds is an arduous task in clinical practice. Early antibacterial strategy and subsequent promotion of granulation tissue growth facilitate to cure the wounds. For this purpose, we fabricated a sequential drug delivery system by incorporation of an injectable hydrogel with porous PLGA microspheres. Vancomycin was linked to the injectable hydrogel via the reversible Schiff's base reaction, and VEGF were encapsulated into PLGA microspheres. After adding vancomycin, the strength and elasticity of the hydrogel were improved, and the gelation time was shortened. The results also demonstrated that the releasing profile of vancomycin was pH-dependent and the VEGF's profile was adjustable by changing the pore sizes of PLGA microspheres. The duration of VEGF release was longer than vancomycin. This hybrid system was valid to inhibit bacteria growth and accelerate vein endothelial cell proliferation in vitro. In rat models, it was effective to manage non-healing infected wounds by reducing inflammation and promoting angiogenesis. In conclusion, this sequential delivery system is promoting to manage non-healing infected wounds, and also provides a new thought to realize the staged drug release.

Ghee and honey dressing for infected wounds

Ghee and honey has been advocated and used as dressing for infected wounds by Sushruta (600BC) and since 1991 in four Mumbai Hospitals. The gratifying results observed with the dressing have prompted this study which aims to establish its efficacy in five recalcitrant subset of chronic infected wounds over a three year period 2006-2009. A standardized ghee and honey dressing was used to treat: a) Eight cases of fungating malignant lesions. b) Thirteen chronic venous ulcers. c) Twenty nine diabetic foot ulcers. d) Eleven of infected ventral hernia mesh hernioplasty. e) Eleven patient with post-cesarean wound dehiscence. The dressing markedly reduced the foul odour and discharge, significantly improving the quality of life in malignant lesions. The results were equivocal in cases of venous ulcers. The results were uniformly good in the last three groups. In view of our results, as also result of innumerable Randomized Control Trials (RCTs) reported on honey dressing for infected wounds, there is substantial evidence that ghee and honey dressing has at least comparable results to other modes of treatment. The easy availability and low cost of this treatment makes it significant in developing countries. Further trials seem warranted.