Riclin-Capped Silver Nanoparticles as an Antibacterial and Anti-Inflammatory Wound Dressing

The effect of biosynthesized silver nanoparticles on Pseudomonas aeruginosa-infected dogs wounds

Environmental factors such as lesion and bacterial infection risk affect wound healing. Many researchers are interested in silver nanoparticles (AgNPs) due to their anti-inflammatory, antibacterial, and wound-healing properties. This study compared AgNPs to Amikacin on dogs' P. aeruginosa-infected wounds. Sixteen dogs were divided into four groups of four and received costo-abdominal right-side full-thickness skin wounds. Thereafter, a bacterial suspension was administered to each wound bed. To assess wound infection, a complete bacterial load count was performed. Clinical wound healing assessments were done (healing rate (%), healing time (days), and comparisons between AgNPs and Amikacin were made to determine their antibacterial actions, as well as histological examination of the skin. Tribulus terrestris was used for the biosynthesis of AgNPs in this study. The AgNPs were characterized using UV-vis spectroscopy, SEM, XRD, EDS, AFM and zeta potential. AgNPs, AgNPs-Amikacin, Amikacin, or no treatment (control group) were topically administered to the wound bed. AgNPs cure wounds in 20 ±  1.64 days, while Amikacin takes 28 ±  1.75. In comparison to amikacin, AgNPs 18 ±  1.47 healed the fastest. AgNPs-Amikacin, AgNPs, and Amikacin can eradicate P. aeruginosa-infected wounds in 7, 9, and 14 days, according to bacterial counts. AgNPs reduce inflammation and increase collagen fiber deposition to treat skin lesions. AgNPs also reduced hemorrhagic areas and inflammatory cells in P. aeruginosa-infected wounds, aiding wound healing. All in all, these nanoparticles reduced bacterial wound infections and aided tissue healing. It has been found that AgNPs can be used as an efficacious antimicrobial and anti-inflammatory agent in wound healing instead of antibiotics.

Superior In Vivo Wound-Healing Activity of Biosynthesized Silver Nanoparticles with Nepeta cataria (Catnip) on Excision Wound Model in Rat

Silver nanoparticles were biosynthesized with Nepeta cataria plant extract. It was determined that the synthesized Nc-AgNPs gave a strong absorbance peak at 438 nm wavelength in the UV-vis spectrophotometer. SEM and TEM analyses of Nc-AgNPs showed that the synthesized nanoparticles had a spherical morphology. Based on XRD analysis, the average crystallite size of Nc-AgNPs was calculated at 15.74 nm. At the same time, EDS spectrum analysis exhibited dominant emission energy at 3 keV, indicative of Nc-AgNPs. Nc-AgNPs showed an inhibition zone of 12 nm in gram-negative Escherichia coli, 10 nm in gram-positive Enterococcus faecalis, and 11 nm in Staphylococcus aureus. Nc-AgNPs showed high antioxidant properties, with 63% at 5000 μg/mL. The wound-healing properties of Nc-AgNPs were evaluated in vivo in wound models created in a total of 20 Wistar albino male rats, divided into four groups. After 10 days of treatment, the highest wound closure rate was seen in the Nc-AgNP + Vaseline (Group IV) treatment group, at 94%. It was observed that Nc-AgNP + Vaseline nanoformulation significantly increased wound healing, similar to Silverdin®, and Vaseline alone supported healing but did not result in complete closure. Histopathological examination revealed an increase in mature Type 1 collagen in Group IV and positive control (Group II), with better collagen maturation in vehicle control (Group III) compared to negative control (Group I). Immunohistochemical analysis showed complete epithelialization in Group IV and Group II, with distinct cytokeratin expressions, while Group III exhibited mild expressions.

Concanavalin-conjugated zinc-metal-organic framework drug for pH-controlled and targeted therapy of wound bacterial infection

Wounds are prone to infection which may be fatal to the life of the patient. The use of antibiotics is essential for managing bacterial infections in wounds, but the long-term use of high doses of antibiotics may lead to bacterial drug resistance and even to creation of superbacteria. Therefore, the development of targeted antimicrobial treatment strategies and the reduction in antibiotic usage are of utmost urgency. In this study, a multifunctional nanodrug delivery system (Cef-rhEGF@ZIF-8@ConA) for the treatment of bacteriostatic infection was synthesized through self-assembly of Zn2+, cefradine (Cef) and recombinant human epidermal growth factor (rhEGF), then conjugated with concanavalin (ConA), which undergoes pH-responsive degradation to release the drugs. First, ConA can specifically combine with bacteria and inhibit the rapid release of Zn2+ ions, thus achieving a long-acting antibacterial effect. Cef exerts its antibacterial effect by inhibiting the synthesis of bacterial membrane proteins. Finally, Zn2+ ions released from the Zn-metal-organic framework (MOF) demonstrate bacteriostatic properties by enhancing the permeability of the bacterial cell membrane. Furthermore, rhEGF upregulates angiogenesis-associated genes, thereby promoting angiogenesis, re-epithelialization and wound healing processes. The results showed that Cef-rhEGF@ZIF-8@ConA has good biocompatibility, with antibacterial efficacy against Staphylococcus aureus and Escherichia coli of 99.61 % and 99.75 %, respectively. These nanomaterials can inhibit the release of inflammatory cytokines and promote the release of anti-inflammatory cytokines, while also stimulating the proliferation of fibroblasts to facilitate wound healing. Taken together, the Cef-rhEGF@ZIF-8@ConA nanosystem is an excellent candidate in clinical therapeutics for bacteriostatic infection and wound healing.

Silver Nanoparticles: A Comprehensive Review of Synthesis Methods and Chemical and Physical Properties

Recently, silver nanoparticles (NPs) have attracted significant attention for being highly desirable nanomaterials in scientific studies as a result of their extraordinary characteristics. They are widely known as effective antibacterial agents that are capable of targeting a wide range of pathogens. Their distinct optical characteristics, such as their localized surface plasmon resonance, enlarge their utilization, particularly in the fields of biosensing and imaging. Also, the capacity to control their surface charge and modify them using biocompatible substances offers improved durability and specific interactions with biological systems. Due to their exceptional stability and minimal chemical reactivity, silver NPs are highly suitable for a diverse array of biological applications. These NPs are produced through chemical, biological, and physical processes, each of which has distinct advantages and disadvantages. Chemical and physical techniques often encounter issues with complicated purification, reactive substances, and excessive energy usage. However, eco-friendly biological approaches exist, even though they require longer processing times. A key factor affecting the stability, size distribution, and purity of the NPs is the synthesis process selected. This review focuses on how essential it is to choose the appropriate synthesis method in order to optimize the characteristics and use of silver NPs.

Injectable nano-in situ-thermosensitive-hydrogels based on halofuginone and silver for postoperative treatment against triple-negative breast cancer

Postoperative distant metastasis and high recurrence rate causes a dilemma in treating triple-negative breast cancer (TNBC) owing to its unforeseeable invasion into various organs or tissues. The wealth of nutrition provided by vascular may facilitate the proliferation and angiogenesis of cancer cells, which further enhance the rates of postoperative metastasis and recurrence. Chemotherapy, as a systemic postoperative adjuvant therapy, is generally applied to diminish recurrence and metastasis of TNBC. Herein, an halofuginone-silver nano thermosensitive hydrogel (HTPM&AgNPs-gel) was prepared via a physical swelling method. The in vitro anticancer efficacy of HTPM&AgNPs-gel was analyzed by investigating cell proliferation, migration, invasion, and angiogenesis capacity. Furthermore, the in vivo anti-cancer activity of HTPM&AgNPs-gel was further appraised through the tumor suppression, anti-metastatic, anti-angiogenic, and anti-inflammatory ability. The optimized HTPM&AgNPs-gel, a thermosensitive hydrogel, showed excellent properties, including syringeability, swelling behavior, and a sustained release effect without hemolysis. In addition, HTPM&AgNPs-gel was confirmed to effectively inhibit the proliferation, migration, invasion, and angiogenesis of MDA-MB-231 cells. An evaluation of the in vivo anti-tumor efficacy demonstrated that HTPM&AgNPs-gel showed a stronger tumor inhibition rate (68.17%) than did HTPM-gel or AgNPs-gel used alone and exhibited outstanding biocompatibility. Notably, HTPM&AgNPs-gel also inhibited lung metastasis induced by residual tumor tissue after surgery and further blocked angiogenesis-related inflammatory responses. Taken together, the suppression of inflammation by interdicting the blood vessels adjoining the tumor and inhibiting angiogenesis is a potential strategy to attenuate the recurrence and metastasis of TNBC. HTPM&AgNPs-gel is a promising anticancer agent for TNBC as a local postoperative treatment.

Anti-inflammatory action of silver nanoparticles in vivo: systematic review and meta-analysis

The aim of this study was to systematically review the literature to investigate whether silver nanoparticles (AgNPs) have an anti-inflammatory effect in vivo. The guidelines of PRISMA were applied, and a registration was made in PROSPERO. A personalized search of the PubMed, Web of Science, Scopus, Embase, Lilacs, and Google Scholar databases was conducted in September 2023. For the data analysis, the inverse variance in the random effects model was used. The tools of SYRCLE and GRADE were used to assess the risk of bias and the certainty of evidence, respectively. From the 9185 identified studies, 5685 duplicate studies were excluded; 52 were read in full text, and 7 were included in this review. Six studies were evaluated by the meta-analysis, and an increase in anti-inflammatory molecules (SMD -5.22; PI [-6.50, -3.94]) and an increase in anti-inflammatory ones (SMD 5.75; PI [3.79, 7.72]) were observed. Qualitative analysis showed a reduction in pro-inflammatory proteins and in the COX-2 pathway. It was concluded that AgNPs present an anti-inflammatory action in vivo through mechanisms involving the reduction of pro-inflammatory molecules and proteins, the increase of anti-inflammatory molecules, and selective inhibition of the COX-2 pathway.

Self-Cleaning Antibacterial Composite Coating of Fluorinated Acrylic Resin and Ag/SiO2 Nanoparticles with Quaternary Ammonium

With improvements in living standards, the demand for antibacterial self-cleaning coatings has significantly increased. In this work, self-cleaning coatings with antibacterial properties were fabricated by spray-coating a composite of fluorinated acrylic resin and Ag/SiO2 nanoparticles with quaternary ammonium salts. The synergistic action of the quaternary ammonium salts and silver nanostructures caused the coating to show a dual antibacterial effect. The Ag/SiO2 nanoparticles roughened the coating's surface and, in combination with the fluorinated chains, provided the surface a superhydrophobic self-cleaning property with a contact angle of 156° and a sliding angle of less than 2°. Notably, the composite coating withstood 100 abrasion cycles without losing its superhydrophobicity and the contact angle is still exceeded 150° after 60 h of immersion solutions with different pH values, demonstrating outstanding wear resistance and acid/alkali stability. The incorporation of nanostructured antibacterial agents was effective in improving the roughness and antibacterial properties of the low-surface-energy resin, resulting in a self-cleaning antibacterial composite coating. This method may pave a new route for the design of functional coating materials with excellent overall performance.

Aggregation-Induced Emission Photosensitizer with Ag(I)-π Interaction-Enhanced Reactive Oxygen Species for Eliminating Multidrug Resistant Bacteria

Multidrug-resistant (MDR) bacteria pose serious threats to public health due to the lack of effective and biocompatible drugs to kill MDR bacteria. Photodynamic antibacterial therapy has been widely studied due to its low induction of resistance. However, photosensitizers that can efficiently generate reactive oxygen species (ROS) through both type I and type II mechanisms and that have the capability of multiple modes of action are rarely reported. Addressing this issue, we developed a near-infrared-emitting triphenylamine indole iodoethane (TTII) and its silver(I) self-assembled (TTIIS) aggregation-induced emission (AIE) photosensitizer for multimode bacterial infection therapy. TTII can efficiently produce both Type I ROS •OH and Type II ROS 1O2. Interestingly, the Ag(I)-π interaction contributed in TTIIS efficiency promotion of the generation of 1O2. Moreover, by releasing Ag+, TTIIS enabled photodynamic-Ag(I) dual-mode sterilization. As a result, TTIIS achieved an effective enhancement of antibacterial activity, with a 1-2-fold boost against multidrug-resistant Escherichia coli (MDR E. coli). Both TTII and TTIIS at a concentration as low as 0.55 μg mL-1 can kill more than 98% of methicillin resistant Staphylococcus aureus (MRSA) on MRSA-infected full-thickness defect wounds of a mouse, and both TTII and TTIIS were effective in eliminating the bacteria and promoting wound healing.

Fermentation-inspired macroporous and tough gelatin/sodium alginate hydrogel for accelerated infected wound healing

Gelatin and sodium alginate (SA) are two important biological macromolecules, exhibiting excellent biocompatibility and gel-forming ability. However, traditional SA and gelatin hydrogel displays limited mass transport, low porosity, instability, and poor mechanical properties extremely restricted their therapeutic effect and application scenarios. Herein, microbial fermentation and synergistic toughening strategies were used for preparing macroporous and tough hydrogel. The study investigated the fermentation and toughening conditions of hydrogel. The hydrogel composed of CaCl2 cross-linked physically network and EDC/NHS cross-linked covalently network, exhibiting significantly improved mechanical properties, and excellent recovery efficiency. In addition, the hydrogel has a hierarchical macroporous structure of 100-500 μm, demonstrating high porosity of 10 times, swelling rate of 1541.0 %, and high mass infiltration capability. Further, after Ag+ treatment, the macroporous hydrogel dressing showed outstanding biocompatibility. Compared with non-porous hydrogel, the resulting macroporous hydrogel dressing displayed high antibacterial and antioxidant properties. It could effectively alleviate intracellular ROS formation induced by H2O2.In vivo experiments indicated that it has significantly better effect than non-porous hydrogel in accelerating wound healing. The overall results suggest that the gelatin/SA-based macroporous and tough hydrogel proposed in this study holds excellent prospects for application in wound dressings.

Versatile Antibacterial and Antioxidant Bacterial Cellulose@Nanoceria Biotextile: Application in Reusable Antimicrobial Face Masks

Despite considerable interest in medical and pharmaceutical fields, there remains a notable absence of functional textiles that concurrently exhibit antibacterial and antioxidant properties. Herein, a new composite fabric constructed using nanostructured bacterial cellulose (BC) covalently-linked with cerium oxide nanoparticles (BC@CeO2NPs) is introduced. The synthesis of CeO2NPs on the BC is performed via a microwave-assisted, in situ chemical deposition technique, resulting in the formation of mixed valence Ce3+/Ce4+ CeO2NPs. This approach ensures the durability of the composite fabric subjected to multiple washing cycles. The Reactive oxygen species (ROS) scavenging activity of CeO2NPs and their rapid and efficient eradication of >99% model microbes, such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus remain unaltered in the composite. To demonstrate the feasibility of incorporating the fabric in marketable products, antimicrobial face masks are fabricated with filter layers made of BC@CeO2NPs cross-linked with propylene or cotton fibers. These masks exhibit complete inhibition of bacterial growth in the three bacterial strains, improved breathability compared to respirator masks and enhanced filtration efficiency compared to single-use surgical face masks. This study provides valuable insights into the development of functional BC@CeO2NPs biotextiles in which design can be extended to the fabrication of medical dressings and cosmetic products with combined antibiotic, antioxidant and anti-inflammatory activities.

Polymer-Based Functional Materials Loaded with Metal-Based Nanoparticles as Potential Scaffolds for the Management of Infected Wounds

Wound infection due to bacterial invasion at the wound site is one of the primary challenges associated with delayed wound healing. Microorganisms tend to form biofilms that protect them from harm, leading to their multidrug resistance. The alarming increase in antibiotic resistance poses a threat to wound healing. Hence, the urgent need for novel wound dressing materials capable of managing bacterial infection is crucial for expediting wound recovery. There is considerable interest in polymeric wound dressings embedded with bioactive substances, such as metal-based nanoparticles, as potential solutions for treating microbially infected wounds. Metal-based nanoparticles have been widely used for the management of infected wounds due to their broad antimicrobial efficacy. This review focuses on polymer-based and bioactive wound dressings loaded with metal-based nanoparticles like silver, gold, magnesium oxide, or zinc oxide. When compared, zinc oxide-loaded dressings exhibited higher antibacterial activity against Gram-positive strains and silver nanoparticle-loaded dressings against gram-negative strains. However, wound dressings infused with both nanoparticles displayed a synergistic effect against both strains of bacteria. Furthermore, these dressings displayed antibiofilm activity and the generation of reactive oxygen species while accelerating wound closure both in vitro and in vivo.

Electrospun Nanofiber Scaffolds Loaded with Metal-Based Nanoparticles for Wound Healing

Failures of wound healing have been a focus of research worldwide. With the continuous development of materials science, electrospun nanofiber scaffolds loaded with metal-based nanoparticles provide new ideas and methods for research into new tissue engineering materials due to their excellent antibacterial, anti-inflammatory, and wound healing abilities. In this review, the stages of extracellular matrix and wound healing, electrospun nanofiber scaffolds, metal-based nanoparticles, and metal-based nanoparticles supported by electrospun nanofiber scaffolds are reviewed, and their characteristics and applications are introduced. We discuss in detail the current research on wound healing of metal-based nanoparticles and electrospun nanofiber scaffolds loaded with metal-based nanoparticles, and we highlight the potential mechanisms and promising applications of these scaffolds for promoting wound healing.

Crosslinked hydrogel loaded with chitosan-supported iron oxide and silver nanoparticles as burn wound dressing

Burns can result in infection, disability, psychosocial and economic issues. Advanced wound dressings like hydrogel absorb exudate and maintain moisture. Considering the antimicrobial properties of silver nanoparticles and iron oxide nanoparticles, the efficiency of cross-linked hydrogel loaded with chitosan-supported iron oxide and silver nanoparticles for burn wounds repair was investigated in animal model. Cellulose hydrogel dressing made from carboxymethylcellulose and hydroxyethylcellulose crosslinked with different concentrations of citric acid (10, 15, 20, and 30%) was produced. The physicochemical characteristics of the synthetized hydrogels including Fourier-Transform Infrared spectroscopy, Thermal behavior, Swelling properties, and Scanning Electron Microscope (SEM) were evaluated. The silver nanoparticles and iron nanoparticles were produced and the characteristics, cytotoxicity, antimicrobial activities and their synergistic effect were investigated. After adding nanoparticles to hydrogels, the effects of the prepared wound dressings were investigated in a 14-day animal model of burn wound. The results showed that the mixture comprising 12.5 ppm AgNps, and IONPs at a concentration ≤100 ppm was non-cytotoxic. Moreover, the formulations with 20% CA had a swelling ratio of almost 250, 340, and 500 g/g at pHs of 5, 6.2, and 7.4 after one hour, which are lower than those of formulations with 5 and 10% CA. The total mass loss (59.31%) and the exothermic degradation happened in the range of 273-335 °C and its Tm was observed at 318.52 °C for hydrogels with 20% CA. Thus, the dressing comprising 20% CA which was loaded with 12.5 ppm silver nanoparticles (AgNPs) and 100 ppm iron oxide nanoparticles (IONPs) indicated better physicochemical, microbial and non-cytotoxic characteristics, and accelerated the process of wound healing after 14 days. It was concluded that the crosslinked hydrogel loaded with 12.5 ppm AgNPs and 100 ppm IONPs possesses great wound healing activity and could be regarded as an effective topical burn wound healing treatment.

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.

Immunomodulatory Nanosystems: Advanced Delivery Tools for Treating Chronic Wounds

The increasingly aging society led to a rise in the prevalence of chronic wounds (CWs), posing a significant burden to public health on a global scale. One of the key features of CWs is the presence of a maladjusted immune microenvironment characterized by persistent and excessive (hyper)inflammation. A variety of immunomodulatory therapies have been proposed to address this condition. Yet, to date, current delivery systems for immunomodulatory therapy remain inadequate and lack efficiency. This highlights the need for new therapeutic delivery systems, such as nanosystems, to manage the pathological inflammatory imbalance and, ultimately, improve the treatment outcomes of CWs. While a plethora of immunomodulatory nanosystems modifying the immune microenvironment of CWs have shown promising therapeutic effects, the literature on the intersection of immunomodulatory nanosystems and CWs remains relatively scarce. Therefore, this review aims to provide a comprehensive overview of the pathogenesis and characteristics of the immune microenvironment in CWs, discuss important advancements in our understanding of CW healing, and delineate the versatility and applicability of immunomodulatory nanosystems-based therapies in the therapeutic management of CWs. In addition, we herein also shed light on the main challenges and future perspectives in this rapidly evolving research field.

Preparation of Antibacterial, Arginine-Modified Ag Nanoclusters in the Hydrogel Used for Promoting Diabetic, Infected Wound Healing

Diabetic foot ulcers with complex healing wounds accompanied by bacterial infection are considered a significant clinical problem which are made worse by the lack of effective treatments. Traditional antibiotics and dressings have failed to address wound infection and healing, and multifunctional combination therapies are attractive for treating chronic wounds. In this study, arginine (Arg) was loaded onto the surface of silver nanoclusters and encapsulated in a hydrogel to achieve antibacterial, anti-inflammatory, angiogenic, and collagen deposition functions through the slow release of Arg combined with silver nanoclusters. In vitro studies indicated that Arg-Ag@H composites inhibited methicillin-resistant Staphylococcus aureus and Escherichia coli by 94 and 97%, respectively. The inhibition of bacterial biofilms reached 85%, and the migration ability of human venous endothelial cells (HUVECs) increased by 50%. In vitro studies showed that Arg-Ag@H composites increased the healing area of wounds by 26% and resulted in a 98% skin wound-healing rate. Safety studies confirmed the excellent biocompatibility of Arg-Ag@H. The results suggest that Arg-Ag@H offers new possibilities for treating chronic diabetic wounds.

A multifunctional sateen woven dressings for treatment of skin injuries

Cutaneous wounds with impaired healing such as diabetic ulcers and burns constitute major and rapidly growing threat to healthcare systems worldwide. Accelerating wound healing requires the delivery of biological factors that induce angiogenesis, support cellular proliferation, and modulate inflammation while minimizing infection. In this study, we engineered a dressing made by weaving of composite fibers (CFs) carrying mesenchymal stem cells (MSCs) and a model antibiotic using a scalable sateen textile technique. In this regard, two different sets of CFs carrying MSCs or an antimicrobial agent were used to generate a multifunctional dressing. According to cell viability and metabolic activity as CCK-8 and live/dead with qRT-PCR results, more than %90 the encapsulated MSCs remain viable for 28 days and their expression levels of the wound repair factors including ECM remodeling, angiogenesis and immunomodulatory maintained in MSCs post dressing manufacturing for 14 days. Post 10 days culture of the dressing, MSCs within CFs had 10-fold higher collagen synthesis (p < 0.0001) determined by hydroxyproline assay which indicates the enhanced healing properties. According to in vitro antimicrobial activity results determined by disk diffusion and broth microdilution tests, the first day and the total amount of release gentamicin loaded dressing samples during the 28 days were higher than determined minimal inhibition concentration (MIC) values for S. aureus and K. pneumonia without negatively impacting the viability and functionality of encapsulated MSCs within the dressing. The dressing is also flexible and can conform to skin curvatures making the dressing suitable for the treatment of different skin injuries such as burns and diabetic ulcers.

Modulation of Macrophage Function by Bioactive Wound Dressings with an Emphasis on Extracellular Matrix-Based Scaffolds and Nanofibrous Composites

Bioactive wound dressings that are capable of regulating the local wound microenvironment have attracted a very large interest in the field of regenerative medicine. Macrophages have many critical roles in normal wound healing, and the dysfunction of macrophages significantly contributes to impaired or non-healing skin wounds. Regulation of macrophage polarization towards an M2 phenotype provides a feasible strategy to enhance chronic wound healing, mainly by promoting the transition of chronic inflammation to the proliferation phase of wound healing, upregulating the level of anti-inflammatory cytokines around the wound area, and stimulating wound angiogenesis and re-epithelialization. Based on this, modulation of macrophage functions by the rational design of bioactive scaffolds has emerged as a promising way to accelerate delayed wound healing. This review outlines current strategies to regulate the response of macrophages using bioactive materials, with an emphasis on extracellular matrix-based scaffolds and nanofibrous composites.

Turmeric Herb Extract-Incorporated Biopolymer Dressings with Beneficial Antibacterial, Antioxidant and Anti-Inflammatory Properties for Wound Healing

Bacterial infection and inflammation caused by excess oxidative stress are serious challenges in chronic wound healing. The aim of this work is to investigate a wound dressing based on natural- and biowaste-derived biopolymers loaded with an herb extract that demonstrates antibacterial, antioxidant, and anti-inflammatory activities without using additional synthetic drugs. Turmeric extract-loaded carboxymethyl cellulose/silk sericin dressings were produced by esterification crosslinking with citric acid followed by freeze-drying to achieve an interconnected porous structure, sufficient mechanical properties, and hydrogel formation in situ in contact with an aqueous solution. The dressings exhibited inhibitory effects on the growth of bacterial strains that were related to the controlled release of the turmeric extract. The dressings provided antioxidant activity as a result of the radical scavenging effect on DPPH, ABTS, and FRAP radicals. To confirm their anti-inflammatory effects, the inhibition of nitric oxide production in activated RAW 264.7 macrophages was investigated. The findings suggested that the dressings could be a potential candidate for wound healing.

Beneficial Effect of Wound Dressings Containing Silver and Silver Nanoparticles in Wound Healing-From Experimental Studies to Clinical Practice

Impaired wound healing affects hundreds of million people around the world; therefore, chronic wounds are a major problem not only for the patient, but also for already overloaded healthcare systems. Chronic wounds are always very susceptible to infections. Billions of dollars are spent to discover new antibiotics as quickly as possible; however, bacterial resistance against antibiotics is rising even faster. For this reason, a complete shift of the antibacterial treatment paradigm is necessary. The development of technology has allowed us to rediscover well-known agents presenting antimicrobial properties with a better outcome. In this context, silver nanoparticles are a promising candidate for use in such therapy. Silver has many useful properties that can be used in the treatment of chronic wounds, such as anti-bacterial, anti-inflammatory, and anti-oxidative properties. In the form of nanoparticles, silver agents can work even more effectively and can be more easily incorporated into various dressings. Silver-based dressings are already commercially available; however, innovative combinations are still being discovered and very promising results have been described. In this review article, the authors focused on describing experimental and clinical studies exploring dressings containing either silver or silver nanoparticles, the results of which have been published in recent years.