Alginate films containing Lactobacillus plantarum as wound dressing for prevention of burn infection

Next-Generation Wound Care: A Scoping Review on Probiotic, Prebiotic, Synbiotic, and Postbiotic Cutaneous Formulations

Background/Objectives: Chronic wounds represent a significant socioeconomic burden, affecting 1-2% of the global population. Wound healing is a complex process involving inflammation, cell proliferation, and tissue remodeling, but factors such as infections, diabetes, aging, and poor nutrition can impair recovery, leading to chronic wounds. Given these challenges, researchers have explored topical probiotics, synbiotics, and postbiotics as alternatives strategies. Strains like Lactobacillus and Bifidobacterium contribute to skin restoration by producing antimicrobial, anti-inflammatory, and immunomodulatory compounds, offering a novel approach to cutaneous restoration. Our study aims to address the potential effects of topical probiotic, synbiotic, and postbiotic formulations for wound healing applications by means of a broad scoping review and evidence-gap mapping. Methods: A systematic literature search of preclinical studies (in vitro and in vivo) was performed in PubMed, Scopus, and Web of Science (January 2025), yielding 3052 articles after duplicates removal, of which 44 met the inclusion criteria. Results: These studies were published between 1986 and 2024, mostly by China (27.3%) and Iran (25.0%). Probiotics were frequently evaluated among the studies included (47.7%) (with Lactobacillus plantarum being the most assessed strain), followed by postbiotics (36.4%) (with predominant use of cell-free supernatants) and synbiotics (15.9%) (especially fructooligosaccharides). Dosage forms included gels (44.4%), films (15.6%), and ointments (13.3%). Conclusions: Most studies indicate that probiotics, synbiotics, and postbiotics have antimicrobial and anti-inflammatory properties, while promoting angiogenesis, tissue regeneration, and skin barrier restoration. The use of different delivery systems may additionally enhance therapeutic outcomes by accelerating wound closure, reducing bacterial load, and modulating immune response. However, methodological limitations in animal studies highlight the need for greater experimental rigor. Further robust clinical trials are essential to confirm efficacy and safety before clinical application of these formulations.

Advancing burn wound healing with an innovative in situ gelling probiotic microparticle formulation employing quality by design (QbD) principles

Scientists investigated probiotic-containing dressings to address the challenges associated with burn injuries, namely infection and antimicrobial resistance. The present investigation sought to evaluate the impact of innovative probiotic-loaded microparticles with in situ gelling characteristics on infected burns. The strain, Lactiplantibacillus plantarum, was selected due to its demonstrated wound-healing potential. Subsequently, a formulation was designed to sustain the growth capacity of probiotics. Polymers with a high moisture absorption capacity were exclusively used to avoid powder dispersion from wounds. The formulation was stabilized through the reduction of water content using the spray-drying process. The ideal composition was identified by analyzing the influence of the spray-drying inlet temperature, polymer type, and concentrations on probiotic viability, process efficiency, swelling ratio, and flow properties of powders. Morphological analysis showed the presence of microparticles with significant exchangeable surface areas. The rheological properties of the formulation demonstrated its ability to withstand high temperatures and mechanical stress. Moreover, FTIR and DCS spectra provided evidence of interconnection between the polymers. Examination of the growth profiles of both formulated and free probiotics revealed a consistent growth rate and an extended lag time. Animal studies have shown that the optimal microparticles exhibited superior efficacy compared to the control groups across all parameters and displayed enhanced effectiveness against Pseudomonas aeruginosa. The proposed delivery method, with its simple application and prevention of normal flora transmission, may have the potential to improve burn wound infection treatments.

The evolution of calcium alginate-based dressings in wound healing: A comprehensive bibliometric review of the top 100 cited studies

Calcium alginate, a naturally derived polysaccharide from brown seaweed, has gained significant prominence in advanced wound care technologies. Despite its widespread application, there is a need for a bibliometric analysis to map the scientific advancements and thematic evolution in the field. To conduct a bibliometric analysis of the top 100 most cited papers on calcium alginate wound dressings to identify key contributors, collaborative networks, prominent themes, and trends in citation impact. The Scopus database was utilized for its broad multidisciplinary coverage. A search string "(wound dressing) AND (calcium alginate)" was applied to the Title, Abstract, and Keywords fields without time restrictions. Only articles and reviews were included. The analysis involved two phases: (1) a general examination of all retrieved publications for productive authors, institutions, countries, sponsors, and sources; and (2) an in-depth analysis of the top 100 most cited papers using VOSviewer and the bibliometrix package in R Studio. Co-authorship, citation networks, keyword co-occurrences, and citation metrics were visualized and statistically analyzed. From a total of 330 publications identified, the United States (57 publications), the United Kingdom (54), and China (46) emerged as leading contributors. Key institutions included Donghua University (9 publications) and Chulalongkorn University (5 publications). Prominent funding sources were the National Natural Science Foundation of China (20 publications) and the Ministry of Science and Technology of China (6 publications). The International Journal of Biological Macromolecules, the International Wound Journal, and the British Journal of Plastic Surgery were frequently cited sources. The top 100 cited papers, spanning 1983-2023, demonstrated peaks in citation impact in 2014 and 2015, with mean citations per article exceeding 270. Co-word analysis revealed evolving research themes over decades, highlighting foundational and innovative contributions. This comprehensive analysis may provide valuable insights into the thematic evolution and emerging trends, serving as a foundation for future research in wound care technologies.

The relationship between the skin microbiome and probiotics in the healing of burn injuries

The relationship between the skin microbiome and probiotics in the healing of burn injuries has garnered significant attention in recent years. Burn injuries disrupt the delicate balance of the skin microbiome, leading to complications in the healing process. Probiotic therapies have emerged as promising interventions to restore microbial balance, inhibit biofilm formation, and accelerate tissue repair. Probiotics may also mitigate the risk of antibiotic-resistant infections, which is a major concern in burn units. By enhancing immune responses and stimulating the production of antimicrobial peptides, probiotics can effectively combat bacterial colonization and prevent the emergence of drug-resistant strains. A combination of probiotics with other therapies, such as phages or nanoparticles, holds significant promise for enhancing burn healing. This approach can effectively treat burn wounds by promoting wound healing synergy, preventing infection, modulating the immune response, and disrupting biofilms. Overall, the relationship between the skin microbiome and probiotics in burn wound healing has substantial potential to advance the field of burn wound management.

Advances in Microbiome-Based Therapeutics for Dermatological Disorders: Current Insights and Future Directions

The human skin hosts an estimated 1000 bacterial species that are essential for maintaining skin health. Extensive clinical and preclinical studies have established the significant role of the skin microbiome in dermatological disorders such as atopic dermatitis, psoriasis, diabetic foot ulcers, hidradenitis suppurativa and skin cancers. In these conditions, the skin microbiome is not only altered but, in some cases, implicated in disease pathophysiology. Microbiome-based therapies (MBTs) represent an emerging category of live biotherapeutic products with tremendous potential as a novel intervention platform for skin diseases. Beyond using established wild-type strains native to the skin, these therapies can be enhanced to express targeted therapeutic molecules, offering more tailored treatment approaches. This review explores the role of the skin microbiome in various common skin disorders, with a particular focus on the development and therapeutic potential of MBTs for treating these conditions.

Carbon source competition within the wound microenvironment can significantly influence infection progression

It is becoming increasingly apparent that commensal skin bacteria have an important role in wound healing and infection progression. However, the precise mechanisms underpinning many of these probiotic interactions remain to be fully uncovered. In this work, we demonstrate that the common skin commensal Cutibacterium acnes can limit the pathogenicity of the prevalent wound pathogen Pseudomonas aeruginosa in vivo. We show that this impact on pathogenicity is independent of any effect on growth, but occurs through a significant downregulation of the Type Three Secretion System (T3SS), the primary toxin secretion system utilised by P. aeruginosa in eukaryotic infection. We also show a downregulation in glucose acquisition systems, a known regulator of the T3SS, suggesting that glucose availability in a wound can influence infection progression. C. acnes is well known as a glucose fermenting organism, and we demonstrate that topically supplementing a wound with glucose reverses the probiotic effects of C. acnes. This suggests that introducing carbon source competition within the wound microenvironment may be an effective way to prevent or limit wound infection.

The Potential Impact of Probiotics on Human Health: An Update on Their Health-Promoting Properties

Probiotics, known to be live microorganisms, have been shown to improve or restore the gut microbiota, which in turn has been linked to improved health. It is believed that probiotics are the modern equivalent of a panacea, with claims that they may treat or prevent different diseases both in children and adults (e.g., from colic in babies to cardiovascular disease, respiratory infection, and cancer in adults). Ever since the early 2000s, probiotic-based fermented foods have had a resurgence in popularity, mostly due to claims made regarding their health benefits. Fermented foods have been associated with the prevention of irritable bowel syndrome, lactose intolerance, gastroenteritis, and obesity, but also other conditions such as chronic diarrhea, allergies, dermatitis, and bacterial and viral infections, all of which are closely related to an unhealthy lifestyle. Recent and ongoing developments in microbiome/microbiota science have given us new research directions for probiotics. The new types, mechanisms, and applications studied so far, and those currently under study, have a great potential to change scientific understanding of probiotics' nutritional applications and human health care. The expansion of fields related to the study of the microbiome and the involvement of probiotics in its improvement foreshadow an era of significant changes. An expanding range of candidate probiotic species is emerging that can address newly elucidated data-driven microbial niches and host targets. In the probiotic field, new variants of microbiome-modulating interventions are being developed, including prebiotics, symbiotics, postbiotics, microbial consortia, live biotherapeutic products, and genetically modified organisms, with renewed interest in polyphenols, fibers, and fermented foods to ensure human health. This manuscript aims to analyze recent, emerging, and anticipated trends in probiotics (sources, doses, mechanism of action, diseases for which probiotics are administered, side effects, and risks) and create a vision for the development of related areas of influence in the field.

Nanocurcumin and viable Lactobacillus plantarum based sponge dressing for skin wound healing

Curcumin loaded solid lipid nanoparticles (CSLNs) and probiotic (Lactobacillus plantarum UBLP-40; L. plantarum) were currently co-incorporated into a wound dressing. The combination with manifold anti-inflammatory, anti-infective, analgesic, and antioxidant properties of both curcumin and L. plantarum will better manage complex healing process. Recent reports indicate that polyphenolics like curcumin improve probiotic effects. Curcumin was nanoencapsulated (CSLNs) to improve its bioprofile and achieve controlled release on the wound bed. Bacteriotherapy (probiotic) is established to promote wound healing via antimicrobial activity, inhibition of pathogenic toxins, immunomodulation, and anti-inflammatory actions. Combination of CSLNs with probiotic enhanced (560%) its antimicrobial effects against planktonic cells and biofilms of skin pathogen, Staphylococcus aureus 9144. The sterile dressing was devised with selected polymers, and optimized for polymer concentration, and dressing characteristics using a central composite design. It exhibited a swelling ratio of 412 ± 36%, in vitro degradation time of 3 h, optimal water vapor transmission rate of 1516.81 ± 155.25 g/m2/day, high tensile strength, low-blood clotting index, case II transport, and controlled release of curcumin. XRD indicated strong interaction between employed polymers. FESEM revealed a porous sponge like meshwork embedded with L. plantarum and CSLNs. It degraded and released L. plantarum, which germinated in the wound bed. The sponge was stable under refrigerated conditions for up to six months. No translocation of probiotic from wound to the internal organs confirmed safety. The dressing exhibited faster wound closure and lowered bioburden in the wound area in mice. This was coupled with a decrease in TNF-α, MMP-9, and LPO levels; and an increase in VEGF, TGF-β, and antioxidant enzymes such as catalase and GSH, establishing multiple healing pathways. Results were compared with CSLNs and probiotic-alone dressings. The dressing was as effective as the silver nanoparticle-based marketed hydrogel dressing; however, the cost and risk of developing resistance would be much lower currently.

Using the Galleria mellonella burn wound and infection model to identify and characterize potential wound probiotics

Burn wound infection is the leading cause of mortality among burn wound patients. One of the most commonly isolated bacterial burn wound pathogens is Pseudomonas aeruginosa, a notorious nosocomial multidrug-resistant pathogen. As a consequence of its recalcitrance to frontline antibiotic therapy, there is an urgent need to develop alternative treatment avenues to tackle this pathogen. One potential alternative infection prevention measure is to seed the wound bed with probiotic bacteria. Several species of Lactobacillus, a common commensal bacterium, have been previously reported to display growth inhibition activity against wound pathogens. Various species of this genus have also been shown to augment the wound healing process, which makes it a promising potential therapeutic agent. Due to the complexity of the burn wound trauma and burn wound infection, an in vivo model is required for the development of novel therapeutics. There are multiple in vivo models that are currently available, the most common among them being the murine model. However, mammalian burn wound infection models are logistically challenging, do not lend themselves to screening approaches and come with significant concerns around ethics and animal welfare. Recently, an invertebrate burn wound and infection model using G. mellonella has been established. This model addresses several of the challenges of more advanced animal models, such as affordability, maintenance and reduced ethical concerns. This study validates the capacity of this model to screen for potential wound probiotics by demonstrating that a variety of Lactobacillus spp. can limit P. aeruginosa burn wound infection and improve survival.

The role of probiotics as wound healers: an overall view

A wound is an injury to the skin or damage to the body tissue. The healing process differs between various kinds of wounds. Treatment of hard-to-heal (chronic) wounds becomes challenging for healthcare practitioners, especially if patients have underlying health complications such as diabetes. Infection of wounds is another factor that interferes with the healing process and extends its duration. Active research is being conducted into the development of advanced wound dressing technologies. These wound dressings are intended to manage the exudate, reduce bacterial infection and speed up the healing process. Probiotics have been receiving much attention because of their potential application in the clinical field, especially in diagnostics and treatment strategies of various infectious and non-infectious diseases. The host immune-modulatory response and antimicrobial activity of probiotics are expanding their role in the development of improved wound dressing technology.

Structures, Properties, and Bioengineering Applications of Alginates and Hyaluronic Acid

In recent years, polymeric materials have been used in a wide range of applications in a variety of fields. In particular, in the field of bioengineering, the use of natural biomaterials offers a possible new avenue for the development of products with better biocompatibility, biodegradability, and non-toxicity. This paper reviews the structural and physicochemical properties of alginate and hyaluronic acid, as well as the applications of the modified cross-linked derivatives in tissue engineering and drug delivery. This paper summarizes the application of alginate and hyaluronic acid in bone tissue engineering, wound dressings, and drug carriers. We provide some ideas on how to replace or combine alginate-based composites with hyaluronic-acid-based composites in tissue engineering and drug delivery to achieve better eco-economic value.

Improved infectious burn wound healing by applying lyophilized particles containing probiotics and prebiotics

Lactiplantibacillus plantarum cells were encapsulated in a mixture of cationic and anionic polymers, with the final composition stabilized through freeze-drying. A D-optimal design was used to examine the effects of different polymer concentrations as well as adding prebiotics on the probiotic viability and swelling behavior of the formulations. Scanning electron micrographs revealed stacked particles capable of rapidly absorbing significant amounts of water. These images corresponded to initial swelling percentages of around 2000% for the optimal formulation. The optimized formula had a viability percentage of more than 82%, with the stability studies suggesting that the powders should be stored at refrigerated temperatures. The physical characteristics of the optimized formula were examined to ensure compatibility with its application. According to antimicrobial evaluations, the difference in pathogen inhibition between formulated and fresh probiotics was less than a logarithm. The final formula was tested in vivo and showed improved wound healing indicators. The optimized formula resulted in a higher rate of wound closure and infection clearance. Furthermore, the molecular studies for oxidative stress indicated that the formula could modify wound inflammatory responses. In histological investigations, the probiotic-loaded particles functioned exactly as efficaciously as silver sulfadiazine ointment did.

The Antimicrobial Effect of Various Single-Strain and Multi-Strain Probiotics, Dietary Supplements or Other Beneficial Microbes against Common Clinical Wound Pathogens

The skin is the largest organ in the human body and is colonized by a diverse microbiota that works in harmony to protect the skin. However, when skin damage occurs, the skin microbiota is also disrupted, and pathogens can invade the wound and cause infection. Probiotics or other beneficial microbes and their metabolites are one possible alternative treatment for combating skin pathogens via their antimicrobial effectiveness. The objective of our study was to evaluate the antimicrobial effect of seven multi-strain dietary supplements and eleven single-strain microbes that contain probiotics against 15 clinical wound pathogens using the agar spot assay, co-culturing assay, and agar well diffusion assay. We also conducted genera-specific and species-specific molecular methods to detect the DNA in the dietary supplements and single-strain beneficial microbes. We found that the multi-strain dietary supplements exhibited a statistically significant higher antagonistic effect against the challenge wound pathogens than the single-strain microbes and that lactobacilli-containing dietary supplements and single-strain microbes were significantly more efficient than the selected propionibacteria and bacilli. Differences in results between methods were also observed, possibly due to different mechanisms of action. Individual pathogens were susceptible to different dietary supplements or single-strain microbes. Perhaps an individual approach such as a 'probiogram' could be a possibility in the future as a method to find the most efficient targeted probiotic strains, cell-free supernatants, or neutralized cell-free supernatants that have the highest antagonistic effect against individual clinical wound pathogens.

Development of guar gum-based dual-layer wound dressing containing Lactobacillus plantarum: Rapid recovery and mechanically flexibility

This study aimed to develop a Lactobacillus plantarum (L. plantarum)-loaded dual-layer wound dressing (DLD) with excellent wound recovery and mechanical properties. L. plantarum-loaded DLD was fabricated by covering the hydrogel (inner layer) with a hydrocolloid (external layer). The hydrocolloid was manufactured by the hot-melt method, consisting of liquid paraffin, polyisobutylene, styrene-isoprene-styrene, and sodium carboxymethylcellulose (12:20:25:43, w/w/w/w). In contrast, the hydrogel was fabricated by the freeze-and-thaw method to load heat-labile L. plantarum. Various non-ionic materials have been investigated to select appropriate hydrogel components. The hydrogel composed of L. plantarum stock solution, guar gum, and polyvinyl alcohol (10:2:10, w/w/w) was chosen for its excellent swelling capacity and mechanical properties. As a result, heat-labile L. plantarum was successfully loaded into the guar-gum-based DLD. Moreover, guar gum-based DLD containing L. plantarum exhibited significantly enhanced swelling capacity and elasticity compared to single hydrogel layer (swelling capacity: DLD, 920.7 ± 32.4 % vs. hydrogel, 282.2 ± 6.5 %; elastic modulus: DLD, 2.9 ± 0.3 × 10^-3 N/mm² vs. hydrogel, 4.2. ± 0.7 × 10^-3 N/mm²). The wound recovery test using Pseudomonas aeruginosa-infected animal model and histological profiles confirmed guar gum-based DLD containing L. plantarum to elicit accelerated wound recovery with complete re-epithelialization compared to commercial product and non-treated (recovery rate at Day 3: DLD, 67.8 ± 6.2 % vs. commercial product, 30.4 ± 11.7 % vs. non-treated, 14.2 ± 7.5 %). Therefore, L. plantarum-loaded DLD is an effective system for wound treatment.

Microencapsulating Alginate-Based Polymers for Probiotics Delivery Systems and Their Application

Probiotics exhibit many health benefits and a great potential for broad applications in pharmaceutical fields, such as prevention and treatment of gastrointestinal tract diseases (irritable bowel syndrome), prevention and therapy of allergies, certain anticancer effects, and immunomodulation. However, their applications are limited by the low viability and metabolic activity of the probiotics during processing, storage, and delivery in the digestive tract. To overcome the mentioned limitations, probiotic delivery systems have attracted much attention. This review focuses on alginate as a preferred polymer and presents recent advances in alginate-based polymers for probiotic delivery systems. We highlight several alginate-based delivery systems containing various types of probiotics and the physical and chemical modifications with chitosan, cellulose, starch, protein, fish gel, and many other materials to enhance their performance, of which the viability and protective mechanisms are discussed. Withal, various challenges in alginate-based polymers for probiotics delivery systems are traced out, and future directions, specifically on the use of nanomaterials as well as prebiotics, are delineated to further facilitate subsequent researchers in selecting more favorable materials and technology for probiotic delivery.

Avoidance of milk and dairy products after oral surgery-is such a recommendation still valid? A cross-sectional study among German and international oral and maxillofacial surgeons and dental practitioners with review of the literature

PURPOSE

For prevention of wound-healing complications, patients in German-speaking countries are traditionally advised to avoid consumption of milk and dairy products after oral surgery. In the absence of national and international guidelines, this study investigates scientific evidence and compares international practice, frequency scale, and rationale behind such recommendation.

METHODS

Comparison of a German cross-sectional mono-center-questionnaire pilot study and a survey among international oral and maxillofacial surgeons (OMFS), specialized oral surgeons and general dentists, evaluating international practice regarding post-operative dietary and nutrition recommendations. Our literature review further assessed scientific evidence for relevant effects of probiotics, prebiotics, and/or synbiotics.

RESULTS

Among German study participants, 56% (n = 64/114) advise patients to avoid milk and dairy products, with 42% of OMFS (n = 38) and 65% (n = 76) of the general dentists recommending abstention (p = .027). In striking contrast, such recommendation could not be identified in our international survey (n = 143) (t test, p < .001) nor in the literature. There were significant differences between German and international study participants regarding the rationale for dietary recommendations, with dental schools and literature most frequently indicated as sources (Fisher's exact test, p < .001).

CONCLUSION

The hypothesis of a harmful effect of the consumption of milk and dairy products after dentoalveolar surgery could not be supported by evidence. The recommendation to avoid dairy products post-surgery was identified as a specific phenomenon practiced almost exclusively in German-speaking countries. Corresponding recommendations, most probably based on a now irrelevant risk of contracting tuberculosis from milk products, can at present no longer be substantiated.

Effects of Probiotics in the Management of Infected Chronic Wounds: From Cell Culture to Human Studies

BACKGROUND

Chronic wounds are commonly associated with polymicrobial biofilm infections. In the last years, the extensive use of antibiotics has generated several antibiotic-resistant variants. To overcome this issue, alternative natural treatments have been proposed, including the use of microorganisms like probiotics. The aim of this manuscript was to review current literature concerning the application of probiotics for the treatment of infected chronic wounds.

METHODS

Relevant articles were searched in the Medline database using PubMed and Scholar, using the keywords "probiotics" and "wound" and "injuries", "probiotics" and "wound" and "ulcer", "biofilm" and "probiotics" and "wound", "biofilm" and "ulcer" and "probiotics", "biofilm" and "ulcer" and "probiotics", "probiotics" and "wound".

RESULTS

The research initially included 253 articles. After removal of duplicate studies, and selection according to specific inclusion and exclusion criteria, 19 research articles were included and reviewed, accounting for 12 in vitro, 8 in vivo studies and 2 human studies (three articles dealing with animal experiments included also in vitro testing). Most of the published studies about the effects of probiotics for the treatment of infected chronic wounds reported a partial inhibition of microbial growth, biofilm formation and quorum sensing.

DISCUSSION

The application of probiotics represents an intriguing option in the treatment of infected chronic wounds with multidrug-resistant bacteria; however, current results are difficult to compare due to the heterogeneity in methodology, laboratory techniques, and applied clinical protocols. Lactobacillus plantarum currently represents the most studied strain, showing a positive application in burns compared to guideline treatments, and an additional mean in chronic wound infections.

CONCLUSIONS

Although preliminary evidence supports the use of specific strains of probiotics in certain clinical settings such as infected chronic wounds, large, long-term clinical trials are still lacking, and further research is needed.

Antibacterial Effect of Copper Sulfide Nanoparticles on Infected Wound Healing

Background: It is widely acknowledged that pathogenic germs delay wound healing to some extent. To explore factors influencing the wound healing process, the current study was conducted to evaluate the antibacterial effect of topical application of copper sulfide nanoparticles (CuS NPs) in vitro and on infected wound healing process in the rat model. Materials and Methods: In this study, the morphology and size of CuS NPs were detected. Staphylococcus aureus and Escherichia coli were used so that the antibacterial ability of CuS NPs could be evaluated better. In addition, a 2-cm circular full-thickness wound infected with a solution of 10⁷ colony forming units (CFU) Staphylococcus aureus was created on the back of each rat. The rats were divided into four groups including the control group, the 100 mcg/mL CuS NPs group, the 250 mcg/mL CuS NPs group, and the 500 mcg/mL CuS NPs group. Tissue bacterial count and histologic assessment were evaluated. Results: The results indicated that CuS NPs had antibacterial activity against Staphylococcus aureus and Escherichia coli. Moreover, they could decrease the incidence of bacterial colonization and promote wound healing through re-epithelialization and collagen deposition. Furthermore, CuS NPs could maintain Cu²⁺ continuous release and inhibit the viability of Staphylococcus aureus through lipid peroxidation. Conclusions: This study found that CuS NPs have fine antibacterial properties, and particularly, the 500 mcg/mL CuS NPs had better effects, without increase of side effects. They could promote infected wound healing, the prospective clinical application of which was further confirmed in the treatment of wound infection.

Cyclic peptide production from lactic acid bacteria (LAB) and their diverse applications

In recent years, cyclic peptides gave gained increasing attention owing to their pH tolerance, heat stability and resistance to enzymatic actions. The increasing outbreaks of antibiotic resistant pathogens and food spoilage have prompted researchers to search for new approaches to combat them. The increasing number of reports on novel cyclic peptides from lactic acid bacteria (LAB) is considered as a breakthrough due to their potential applications. Although an extensive investigation is required to understand the mechanism of action and range of applications, LAB cyclic peptides can be considered as potential substitutes for commercially available antibiotics and bio preservatives. This review summarizes the current updates of LAB cyclic peptides with emphasis on their structure, mode of action and applications. Recent trends in cyclic peptide applications are also discussed.

Phase Diagram and Estimation of Flory-Huggins Parameter of Interaction of Silk Fibroin/Sodium Alginate Blends

Silk fibroin (SF) and sodium alginate (SA) are natural polymers used to produce biomaterials. One of the strategies to improve the properties of these products is to prepare blends with them, which are partially miscible. Phase separation is observed, therefore, the thermodynamic analysis of this system is important to predict the final state and composition of this blends. This study explored blends with a different initial composition of SF, SA, and water (WA) at 25°C and neutral pH. After phase separation, two phases were identified, one rich in SF and other rich in SA. The Flory-Huggins parameters of interaction of polymer-solvent and polymer-polymer were estimated using the extended equation and data of phase equilibrium, their values indicates the partial miscibility of the polymers.

The evaluation of the effect of probiotics on the healing of equine distal limb wounds

The effect of dressings saturated with either a standardized suspension of probiotic bacteria or saline on healing of traumatic distal limb wounds in horses was evaluated for 24 days, and the systemic inflammatory effect was assessed. The wounds were divided in two groups based on the phase of healing: wounds with an incomplete (ICGB) or a complete granulation bed (CGB). The wound area was expressed as percentage of the wound area at day 0 and defined as relative wound area. The mean relative wound area decreased faster in probiotic than saline treated wounds. The difference was most obvious in CGB and increased rapidly from day 0 until day 12 up to 30%, and stabilized around 25% thereafter until the end of the observation period, but it was not statistically significant because of the large variation within the treatment groups. The mean wound area of CGB decreased to 28.4% (range: 6.3 to 49.3) with probiotic and to 51.9% (range: 29.3 to 81.7) with saline treatment at day 24. Additionally, the rate to 50% healing in CGB was 3.4 faster with probiotic compared to saline treatment, whereas in ICGB this was 1.9 faster. Topical probiotics did not increase serum amyloid A and white blood cell counts. Although the mentioned differences were not statistically significant, the clinical relevance of the effect of treatment with probiotics in CGB wounds is clear, supported by the differences in mean wound area in course of time and the time required to reach 50% healing (day 12 for probiotic vs more than day 24 for saline treated wounds). Thus the probiotic treated wounds reached 50% reduction in wound area in half of the time of the saline treated wounds. The topical use of probiotics can be considered as safe as it did not cause a systemic effect.

Development and characterization of carboxymethyl cellulose based probiotic nanocomposite film containing cellulose nanofiber and inulin for chicken fillet shelf life extension

Bioactive packaging is an alternative new technology for preserving the quality and safety of food products with providing health benefits. In this way, the Lactobacillus plantarum, cellulose nanofiber (CNF) and inulin incorporated carboxymethyl cellulose (CMC) based probiotic nanocomposite film was prepared. The fabricated film samples were characterized by FTIR, FE-SEM, XRD and DSC analyses, that the obtained results indicated the good compatibility between CMC, CNF, and inulin. As a result, the CMC-based probiotic films containing CNF and inulin exhibited satisfactory water barrier and mechanical properties. Additionally, the viability of probiotic bacteria in the CMC-based films was significantly (p < 0.05) increased (36%) by addition of inulin as a prebiotic ingredient during storage time. Probiotic film sample showed antibacterial activity against nine pathogens and also extended the chicken fillet shelf life when wrapped on the meat. In conclusion, the application of CNF and inulin incorporated CMC-based probiotic nanocomposite film as a bioactive food packaging system opens up a new horizon for improving the shelf life of food products and providing the health benefits for consumers.

Alginate-based composite materials for wound dressing application:A mini review

Alginate biopolymer has been used in the design and development of several wound dressing materials in order to improve the efficiency of wound healing. Mainly, alginate improves the hydrophilic nature of wound dressing materials in order to create the required moist wound environment, remove wound exudate and increase the speed of skin recovery of the wound. In addition, alginate can easily cross-link with other organic and inorganic materials and they can promote wound healing in clinical applications. This review article addresses the importance of alginates and the roles of derivative polymeric materials in wound dressing biomaterials. Additionally, studies on recent alginate-based wound dressing materials are discussed.

Efficacy of Using Probiotics with Antagonistic Activity against Pathogens of Wound Infections: An Integrative Review of Literature

The skin and its microbiota serve as physical barriers to prevent invasion of pathogens. Skin damage can be a consequence of illness, surgery, and burns. The most effective wound management strategy is to prevent infections, promote healing, and prevent excess scarring. It is well established that probiotics can aid in skin healing by stimulating the production of immune cells, and they also exhibit antagonistic effects against pathogens via competitive exclusion of pathogens. Our aim was to conduct a review of recent literature on the efficacy of using probiotics against pathogens that cause wound infections. In this integrative review, we searched through the literature published in the international following databases: PubMed, ScienceDirect, Web of Science, and Scopus using the search terms “probiotic” AND “wound infection.” During a comprehensive review and critique of the selected research, fourteen in vitro studies, 8 animal studies, and 19 clinical studies were found. Two of these in vitro studies also included animal studies, yielding a total of 39 articles for inclusion in the review. The most commonly used probiotics for all studies were well-known strains of the species Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus rhamnosus. All in vitro studies showed successful inhibition of chosen skin or wound pathogens by the selected probiotics. Within the animal studies on mice, rats, and rabbits, probiotics showed strong opportunities for counteracting wound infections. Most clinical studies showed slight or statistically significant lower incidence of surgical site infections, foot ulcer infection, or burn infections for patients using probiotics. Several of these studies also indicated a statistically significant wound healing effect for the probiotic groups. This review indicates that exogenous and oral application of probiotics has shown reduction in wound infections, especially when used as an adjuvant to antibiotic therapy, and therefore the potential use of probiotics in this field remains worthy of further studies, perhaps focused more on typical skin inhabitants as next-generation probiotics with high potential.

Recent Advances in Non-Conventional Antimicrobial Approaches for Chronic Wound Biofilms: Have We Found the 'Chink in the Armor'?

Chronic wounds are a major healthcare burden, with huge public health and economic impact. Microbial infections are the single most important cause of chronic, non-healing wounds. Chronic wound infections typically form biofilms, which are notoriously recalcitrant to conventional antibiotics. This prompts the need for alternative or adjunct ‘anti-biofilm’ approaches, notably those that account for the unique chronic wound biofilm microenvironment. In this review, we discuss the recent advances in non-conventional antimicrobial approaches for chronic wound biofilms, looking beyond standard antibiotic therapies. These non-conventional strategies are discussed under three groups. The first group focuses on treatment approaches that directly kill or inhibit microbes in chronic wound biofilms, using mechanisms or delivery strategies distinct from antibiotics. The second group discusses antimicrobial approaches that modify the biological, chemical or biophysical parameters in the chronic wound microenvironment, which in turn enables the disruption and removal of biofilms. Finally, therapeutic approaches that affect both, biofilm bacteria and microenvironment factors, are discussed. Understanding the advantages and limitations of these recent approaches, their stage of development and role in biofilm management, could lead to new treatment paradigms for chronic wound infections. Towards this end, we discuss the possibility that non-conventional antimicrobial therapeutics and targets could expose the ‘chink in the armor’ of chronic wound biofilms, thereby providing much-needed alternative or adjunct strategies for wound infection management.

Nanomedicine and advanced technologies for burns: Preventing infection and facilitating wound healing

According to the latest report from the World Health Organization, an estimated 265,000 deaths still occur every year as a direct result of burn injuries. A widespread range of these deaths induced by burn wound happens in low- and middle-income countries, where survivors face a lifetime of morbidity. Most of the deaths occur due to infections when a high percentage of the external regions of the body area is affected. Microbial nutrient availability, skin barrier disruption, and vascular supply destruction in burn injuries as well as systemic immunosuppression are important parameters that cause burns to be susceptible to infections. Topical antimicrobials and dressings are generally employed to inhibit burn infections followed by a burn wound therapy, because systemic antibiotics have problems in reaching the infected site, coupled with increasing microbial drug resistance. Nanotechnology has provided a range of molecular designed nanostructures (NS) that can be used in both therapeutic and diagnostic applications in burns. These NSs can be divided into organic and non-organic (such as polymeric nanoparticles (NPs) and silver NPs, respectively), and many have been designed to display multifunctional activity. The present review covers the physiology of skin, burn classification, burn wound pathogenesis, animal models of burn wound infection, and various topical therapeutic approaches designed to combat infection and stimulate healing. These include biological based approaches (e.g. immune-based antimicrobial molecules, therapeutic microorganisms, antimicrobial agents, etc.), antimicrobial photo- and ultrasound-therapy, as well as nanotechnology-based wound healing approaches as a revolutionizing area. Thus, we focus on organic and non-organic NSs designed to deliver growth factors to burned skin, and scaffolds, dressings, etc. for exogenous stem cells to aid skin regeneration. Eventually, recent breakthroughs and technologies with substantial potentials in tissue regeneration and skin wound therapy (that are as the basis of burn wound therapies) are briefly taken into consideration including 3D-printing, cell-imprinted substrates, nano-architectured surfaces, and novel gene-editing tools such as CRISPR-Cas.

Safety of transtympanic application of probiotics in a chinchilla animal model

Background

Chronic suppurative otitis media can be recalcitrant and difficult to treat, particularly with the increasing occurrence of antibiotic resistance. Lactobacillus plantarum is a probiotic that has been shown to decrease S. aureus and P. aeruginosa growth in wounds, making it a good candidate for the treatment of chronic suppurative otitis media. However, before it can be applied in the ear, its ototoxicity potential must be evaluated.

Methods

A prospective controlled trial was conducted in a chinchilla animal model at the Animal care research facilities of the Montreal Children’s Hospital Research Institute to determine whether Lactobacillus plantarum is ototoxic when applied transtympanically. Ten chinchillas each had one ear randomly assigned to receive 10⁹ CFU/mL of Lactobacillus plantarum solution, while the contralateral ear received saline. Auditory brainstem responses were measured bilaterally at 8, 20, 25 kHz before, at 7–10 days after application, and at 28 days after application of probiotic or saline. Facial nerve and vestibular function were assessed clinically.

Results

There were no statistically significant differences in hearing thresholds between control and experimental ears at 28 days after application. A difference of 11 dB was noted in the 25 kHz range at day 7–10, but resolved by day 28. No animals receiving probiotics developed vestibular nerve dysfunction. There was no histologic evidence of auditory hair cell damaged evidenced by scanning electron microscopy.

Conclusion

Our study suggests that a single application of Lactobacillus plantarum at 10⁹ CFU/mL does not cause ototoxicity in a chinchilla animal model. These preliminary safety evaluations and the pathogen inhibitory effects of L. plantarum demonstrated by previous studies present this probiotic as a candidate of interest for further investigation.

Electronic supplementary material

The online version of this article (10.1186/s40463-017-0242-y) contains supplementary material, which is available to authorized users.

Contribution of the Pseudomonas fluorescens MFE01 Type VI Secretion System to Biofilm Formation

Type VI secretion systems (T6SSs) are widespread in Gram-negative bacteria, including Pseudomonas. These macromolecular machineries inject toxins directly into prokaryotic or eukaryotic prey cells. Hcp proteins are structural components of the extracellular part of this machinery. We recently reported that MFE01, an avirulent strain of Pseudomonas fluorescens, possesses at least two hcp genes, hcp1 and hcp2, encoding proteins playing important roles in interbacterial interactions. Indeed, P. fluorescens MFE01 can immobilise and kill diverse bacteria of various origins through the action of the Hcp1 or Hcp2 proteins of the T6SS. We show here that another Hcp protein, Hcp3, is involved in killing prey cells during co-culture on solid medium. Even after the mutation of hcp1, hcp2, or hcp3, MFE01 impaired biofilm formation by MFP05, a P. fluorescens strain isolated from human skin. These mutations did not reduce P. fluorescens MFE01 biofilm formation, but the three Hcp proteins were required for the completion of biofilm maturation. Moreover, a mutant with a disruption of one of the unique core component genes, MFE01ΔtssC, was unable to produce its own biofilm or inhibit MFP05 biofilm formation. Finally, MFE01 did not produce detectable N-acyl-homoserine lactones for quorum sensing, a phenomenon reported for many other P. fluorescens strains. Our results suggest a role for the T6SS in communication between bacterial cells, in this strain, under biofilm conditions.

Inhibition of glycogen synthase kinase-3β attenuates organ injury and dysfunction associated with liver ischemia-reperfusion and thermal injury in the rat

Glycogen synthase kinase 3 (GSK-3) is a serine-threonine kinase discovered decades ago to have an important role in glycogen metabolism. Today, we know that this kinase is involved in the regulation of many cell functions, including insulin signaling, specification of cell fate during embryonic development, and the control of cell division and apoptosis. Insulin and TDZD-8 (4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione) are inhibitors of GSK-3β that have been shown to possess organ-protective effects in inflammatory-mediated organ injury models. We aimed to evaluate the cytoprotective effect of GSK-3β inhibition on rat models of liver ischemia-reperfusion and thermal injury. In the liver ischemia-reperfusion model, TDZD-8 and insulin were administered at 5 mg/kg (i.v.) and 1.4 IU/kg (i.v.), respectively, 30 min before induction of ischemia and led to the significant reduction of the serum concentration of aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, and lactate dehydrogenase. Beneficial effects were found to be independent from blood glucose levels. In the thermal injury model, TDZD-8 was administered at 5 mg/kg (i.v.) 5 min before induction of injury and significantly reduced multiple organ dysfunction markers (liver, neuromuscular, and lung). In the lung, TDZD-8 reduced the histological signs of tissue injury, inflammatory markers (cytokines), and neutrophil chemotaxis/infiltration; reduced GSK-3β, nuclear factor-κB, and Akt activation; reduced caspase-3 and metalloproteinase-9 activation. Our study provides a new insight on the beneficial effects of GSK-3β inhibition on systemic inflammation and further elucidates the mechanism and pathway crosstalks by which TDZD-8 reduces the multiple organ injury elicited by thermal injury.

Erythropoietin reduces acute lung injury and multiple organ failure/dysfunction associated to a scald-burn inflammatory injury in the rat

Erythropoietin (EPO) is an endogenous regulator of erythropoiesis and is given exogenously as a replacement therapy for selected red blood cell disorders. In the past years, EPO has been emerging as a multifunctional, cytoprotective cytokine with anti-apoptotic, anti-inflammatory, and immunomodulatory properties. We aimed to evaluate the cytoprotective effect of rhEPO (recombinant human EPO) treatment on a rat model of multiorgan dysfunction induced by thermal injury. rhEPO was administered at 1000 U/kg (i.v.) 5 min prior to induction of injury and significantly reduced multiorgan dysfunction markers (liver, kidney, lung, serum cytokine levels). In the lung, rhEPO reduced: histological signs of tissue injury, inflammatory/injury markers on the bronchoalveolar fluid, neutrophil chemotaxis/infiltration, GSK-3β activation, and apoptosis. Our study showed that erythropoietin has the potential to exhibit pleiotropic cytoprotective effects and that it might be an interesting pharmacological strategy in the modulation of acute lung injury, such as the one associated to severe burn.

Alginate hydrogels coated with chitosan for wound dressing

In this work, a coating of chitosan onto alginate hydrogels was realized using the water-soluble hydrochloride form of chitosan (CH-Cl), with the dual purpose of imparting antibacterial activity and delaying the release of hydrophilic molecules from the alginate matrix. Alginate hydrogels with different calcium contents were prepared by the internal setting method and coated by immersion in a CH-Cl solution. Structural analysis by cryo-scanning electron microscopy was carried out to highlight morphological alterations due to the coating layer. Tests in vitro with human mesenchymal stromal cells (MSC) were assessed to check the absence of toxicity of CH-Cl. Swelling, stability in physiological solution and release characteristics using rhodamine B as the hydrophilic model drug were compared to those of relative uncoated hydrogels. Finally, antibacterial activity against Escherichia coli was tested. Results show that alginate hydrogels coated with chitosan hydrochloride described here can be proposed as a novel medicated dressing by associating intrinsic antimicrobial activity with improved sustained release characteristics.

Anti-inflammatory effect of rosmarinic acid and an extract of Rosmarinus officinalis in rat models of local and systemic inflammation

Rosmarinic acid is a polyphenolic compound and main constituent of Rosmarinus officinalis and has been shown to possess antioxidant and anti-inflammatory properties. We aimed to evaluate the anti-inflammatory properties of rosmarinic acid and of an extract of R. officinalis in local inflammation (carrageenin-induced paw oedema model in the rat), and further evaluate the protective effect of rosmarinic acid in rat models of systemic inflammation: liver ischaemia-reperfusion (I/R) and thermal injury models. In the local inflammation model, rosmarinic acid was administered at 10, 25 and 50 mg/kg (p.o.), and the extract was administered at 10 and 25 mg/kg (equivalent doses to rosmarinic acid groups) to male Wistar rats. Administration of rosmarinic acid and extract at the dose of 25 mg/kg reduced paw oedema at 6 hr by over 60%, exhibiting a dose-response effect, suggesting that rosmarinic was the main contributor to the anti-inflammatory effect. In the liver I/R model, rosmarinic acid was administered at 25 mg/kg (i.v.) 30 min. prior to the induction of ischaemia and led to the significant reduction in the serum concentration of transaminases (AST and ALT) and LDH. In the thermal injury model, rosmarinic acid was administered at 25 mg/kg (i.v.) 5 min. prior to the induction of injury and significantly reduced multi-organ dysfunction markers (liver, kidney, lung) by modulating NF-κB and metalloproteinase-9. For the first time, the anti-inflammatory potential of rosmarinic acid has been identified, as it causes a substantial reduction in inflammation, and we speculate that it might be useful in the pharmacological modulation of injuries associated to inflammation.

Physical properties and antifungal activity of bioactive films containing Wickerhamomyces anomalus killer yeast and their application for preservation of oranges and control of postharvest green mold caused by Penicillium digitatum

This study assessed the ability of two bio-based films, obtained from sodium alginate (NaAlg) and locust bean gum (LBG), to protect the viability of Wickerhamomyces anomalus cells and control the growth of Penicillium digitatum. The effect of microbial cell incorporation on physical properties of the developed films was evaluated in terms of barrier, mechanical and optical properties. Furthermore, the application of these two matrices as bioactive coatings was investigated in order to evaluate their efficacy in preserving the postharvest quality of 'Valencia' oranges and inhibiting the growth of P. digitatum on artificially inoculated fruits. Results showed that NaAlg and LBG films were able to maintain more than 85% of the initial W. anomalus yeast population and that the developed films incorporating the killer yeast completely inhibited the growth of P. digitatum in synthetic medium. Likewise, NaAlg and LBG coatings enriched with W. anomalus yeast were effective at reducing weight loss and maintaining firmness of 'Valencia' oranges during storage, and reduced green mold in inoculated fruits by more than 73% after 13 days.

Spray-by-spray in situ cross-linking alginate hydrogels delivering a tea tree oil microemulsion

In this paper we propose an in situ forming ionically cross-linked alginate (Alg) hydrogel delivering a Tea Tree Oil microemulsion (MeTTO) and potentially useful as an advanced dressing for infected wounds. Alg hydrogels were prepared by a spray-by-spray deposition method with the aim to minimize the discomforts during application. From pseudoternary phase diagrams, it was found that proper combination of TTO, water, polysorbate 80 and ethanol gave stable spherical MeTTO with good antimicrobial activity. On this basis, MeTTO at 20% TTO was selected for further inclusion in an Alg hydrogel prepared by alternating sprays of Alg/MeTTO and calcium chloride solutions. Homogeneous dispersion of MeTTO inside cross-linked Alg was assessed by different macroscopic and microscopic methods demonstrating the superior propensity of MeTTO to be integrated in the water-based hydrogel as compared to TTO. Antimicrobial effect of Alg/MeTTO hydrogels on Escherichia Coli strains was remarkable, highlighting the potential of the system as bioactive wound dressing.

Alginate films containing viable Lactobacillus plantarum: preparation and in vitro evaluation

The objective of the study was to develop calcium alginate films, containing Lactobacillus plantarum ATCC 8040 with preserved and stable viability and antibacterial activity. L. plantarum-loaded films containing different calcium concentrations were physically characterized for mechanical and bioadhesive properties and lactobacilli release. The viability and antibacterial activity of L. plantarum was studied before and after processing, and during 6 months of storage. A multiresistant clinical isolate, VIM-2-metalo-β-lactamase producing Pseudomonas aeruginosa, was used as an indicator strain. Interference between L. plantarum and films enhanced films elasticity, water absorption ability, release of lactobacilli, and decreased films adherence. A decrease of L. plantarum viability in alginate films (≤1 log unit) was observed after freeze drying. L. plantarum, at cell concentrations of 108 cfu/ml, was inhibitory active. The viability and antibacterial activity of the immobilized lactobacilli remained stable during 6 months of storage. The study has proved the potential of alginate films to deliver L. plantarum in high numbers to individuals.