Development and In Vivo Characterization of Probiotic Lysate-Treated Chitosan Nanogel as a Novel Biocompatible Formulation for Wound Healing

Postbiotics-peptidoglycan, lipoteichoic acid, exopolysaccharides, surface layer protein and pili proteins-Structure, activity in wounds and their delivery systems

Chronic wound healing is a pressing global public health concern. Abuse and drug resistance of antibiotics are the key problems in the treatment of chronic wounds at present. Postbiotics are a novel promising strategy. Previous studies have reported that postbiotics have a wide range of biological activities including antimicrobial, immunomodulatory, antioxidant and anti-inflammatory abilities. However, several aspects related to these postbiotic activities remain unexplored or poorly known. Therefore, this work aims to outline general aspects and emerging trends in the use of postbiotics for wound healing, such as the production, characterization, biological activities and delivery strategies of postbiotics. In this review, a comprehensive overview of the physiological activities and structures of postbiotic biomolecules that contribute to wound healing is provided, such as peptidoglycan, lipoteichoic acid, bacteriocins, exopolysaccharides, surface layer proteins, pili proteins, and secretory proteins (p40 and p75 proteins). Considering the presence of readily degradable components in postbiotics, potential natural polymer delivery materials and delivery systems are emphasized, followed by the potential applications and commercialization prospects of postbiotics. These findings suggest that the treatment of chronic wounds with postbiotic ingredients will help provide new insights into wound healing and better guidance for the development of postbiotic products.

Chitosan alchemy: transforming tissue engineering and wound healing

Chitosan, a biopolymer acquired from chitin, has emerged as a versatile and favorable material in the domain of tissue engineering and wound healing. Its biocompatibility, biodegradability, and antimicrobial characteristics make it a suitable candidate for these applications. In tissue engineering, chitosan-based formulations have garnered substantial attention as they have the ability to mimic the extracellular matrix, furnishing an optimal microenvironment for cell adhesion, proliferation, and differentiation. In the realm of wound healing, chitosan-based dressings have revealed exceptional characteristics. They maintain a moist wound environment, expedite wound closure, and prevent infections. These formulations provide controlled release mechanisms, assuring sustained delivery of bioactive molecules to the wound area. Chitosan's immunomodulatory properties have also been investigated to govern the inflammatory reaction during wound healing, fostering a balanced healing procedure. In summary, recent progress in chitosan-based formulations portrays a substantial stride in tissue engineering and wound healing. These innovative approaches hold great promise for enhancing patient outcomes, diminishing healing times, and minimizing complications in clinical settings. Continued research and development in this field are anticipated to lead to even more sophisticated chitosan-based formulations for tissue repair and wound management. The integration of chitosan with emergent technologies emphasizes its potential as a cornerstone in the future of regenerative medicine and wound care. Initially, this review provides an outline of sources and unique properties of chitosan, followed by recent signs of progress in chitosan-based formulations for tissue engineering and wound healing, underscoring their potential and innovative strategies.

Trinitroglycerin-loaded chitosan nanogels: Shedding light on cytotoxicity, antioxidativity, and antibacterial activities

AIM AND BACKGROUND

Trinitroglycerin (TNG) is a remarkable NO-releasing agent. Here, we synthesized TNG based on chitosan Nanogels (Ngs) for ameliorating complications associated with high-dose TNG administration.

METHOD

TNG-Ngs fabricated through ionic-gelation technique. Fourier-transformed infrared (FT-IR), zeta-potential, dynamic light scattering (DLS), and electron microscopy techniques evaluated the physicochemical properties of TNG-Ngs. MTT was used to assess the biocompatibility of TNG-Ngs, as the antioxidative properties were determined via lactate dehydrogenase (LDH), reactive oxygen species (ROS), and lipid peroxide (LPO) assays. The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE).

RESULTS

Physicochemical characterization reveals that TNG-Ngs with size diameter (96.2 ± 29 nm), polydispersity index (PDI, 0.732), and negative zeta potential (-1.1 mv) were fabricated. The encapsulation efficacy (EE) and loading capacity (LC) were obtained at 71.1 % and 2.3 %, respectively, with no considerable effect on particle size and morphology. The cytotoxicity assay demonstrated that HepG2 cells exposed to TNG-Ngs showed relative cell viability (RCV) of >80 % for 70 μg/ml compared to the TNG-free drug at the same concentration (P < 0.05). TNG-Ngs showed significant differences with the TNG-free drug for LDH, LPO, and ROS formation at the same concentration (P < 0.001). The antibacterial activity of the TNG-Ngs against S. aureus, E. coli, VRE, and MRSA was higher than the TNG-free drug and Ngs (P < 0.05).

CONCLUSION

TNG-Ngs with enhanced antibacterial and antioxidative activity and no obvious cytotoxicity might be afforded as novel nanoformulation for promoting NO-dependent diseases.

Emerging Multiscale Biofabrication Approaches for Bacteriotherapy

Bacteriotherapy is emerging as a strategic and effective approach to treat infections by providing putatively harmless bacteria (i.e., probiotics) as antagonists to pathogens. Proper delivery of probiotics or their metabolites (i.e., post-biotics) can facilitate their availing of biomaterial encapsulation via innovative manufacturing technologies. This review paper aims to provide the most recent biomaterial-assisted strategies proposed to treat infections or dysbiosis using bacteriotherapy. We revised the encapsulation processes across multiscale biomaterial approaches, which could be ideal for targeting different tissues and suit diverse therapeutic opportunities. Hydrogels, and specifically polysaccharides, are the focus of this review, as they have been reported to better sustain the vitality of the live cells incorporated. Specifically, the approaches used for fabricating hydrogel-based devices with increasing dimensionality (D)-namely, 0D (i.e., particles), 1D (i.e., fibers), 2D (i.e., fiber meshes), and 3D (i.e., scaffolds)-endowed with probiotics, were detailed by describing their advantages and challenges, along with a future overlook in the field. Electrospinning, electrospray, and 3D bioprinting were investigated as new biofabrication methods for probiotic encapsulation within multidimensional matrices. Finally, examples of biomaterial-based systems for cell and possibly post-biotic release were reported.

Protein/polysaccharide-based hydrogels loaded probiotic-mediated therapeutic systems: A review

The natural characteristics of protein/polysaccharide-based hydrogels, as a potential drug delivery platform, have attracted extensive attention. Probiotics have attracted renewed interest in drug research because of their beneficial effects on host health. The idea of using probiotics loaded on protein/polysaccharide-based hydrogels as potential drugs to treat different diseases has been put forward and shows great prospects. Based on this, in this review, we highlight the design strategy of hydrogels loaded probiotic-mediated therapy systems and review the potential diseases that have been proved to be treatable in the laboratory, including promoting wound healing and improving intestinal health and vaginal health, and discuss the challenges existing in the current design.

Using chitosan, hyaluronic acid, alginate, and gelatin-based smart biological hydrogels for drug delivery in oral mucosal lesions: A review

AIMS

Oral mucosal diseases can lead to pain, difficulty speaking and eating, psychological distress, and cancer. Topical drug delivery using biological macromolecules, specifically hydrogels, is gaining interest due to the drawbacks of conventional treatments for oral mucosal lesions.

SCOPE

Biological hydrogels made from natural polymers and their derivatives, such as chitosan, hyaluronic acid, alginate, and gelatin, represent promising alternatives to conventional oral medication delivery methods. Topical drug delivery is beneficial for oral mucosal lesions as it can directly target the affected area, especially with the development of smart stimuli-responsive hydrogels, which allow for more controlled drug release. Biological hydrogels have already been used to deliver drugs like lidocaine and nystatin. This review summarizes the current research on applying smart natural polymer-based hydrogels for drug delivery in oral mucosal lesions.

CONCLUSION

Smart biological hydrogels show great promise as topical drug delivery systems for oral mucosal lesions, offering sustained drug release, increased therapeutic efficacy, and minimized systemic complications. Technological advancement is expected to lead to the development of more effective and safer drug delivery systems. The potential benefits of biological polymer-based hydrogels make them an exciting area of research for oral mucosal lesion treatment.

Simvastatin-Releasing Nanofibrous Peptide Hydrogels for Accelerated Healing of Diabetic Wounds

Wound healing is one of the major global health concerns in diabetic patients. Simvastatin (SMV) is a poorly soluble oral cholesterol-lowering drug that may aid diabetic wound healing. In the current study, a thixotropic peptide hydrogel of Fmoc-diphenylalanine (FmocFF) containing SMV was designed to accelerate skin wound healing effectively and safely in diabetic mice. FmocFF hydrogels were prepared at various concentrations by using the solvent-triggering technique and characterized by spectroscopic methods such as attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy and fluorimetry. Mechanical behaviors were explored by oscillatory rheology. In model mice, the regenerative potential of the FmocFF-SMV hydrogel was evaluated in terms of wound contraction and closure, tissue regeneration, acute and chronic inflammation, granulation, and re-epithelization. The results showed that FmocFF-SMV hydrogels had an entangled nanofibrous microstructure and shear-thinning characteristics. FmocFF-SMV demonstrated a sustained drug release over 7 days. Compared to the unloaded FmocFF hydrogel, treatment with FmocFF-SMV led to superior diabetic wound recovery and reduced inflammation. Therefore, the utilization of the sustained-release FmocFF-SMV hydrogel formulation could become an attractive choice for topical wound therapy in diabetes patients.

Pharmacotechnical aspects of a stable probiotic formulation toward multidrug-resistance antibacterial activity: design and quality control

As a well-known group of the probiotic family, the Lactobacillus has increasingly contributed to hindering the growth of pathogens, particularly resistant species, in the last decades. Since antibiotic resistance has become a severe problem in global healthcare systems and considerably increased the mortality and morbidity rate in infectious diseases, we aimed to obtain a new stable formulation of Lactobacillus to overcome resistant infections. For this purpose, we designed various gel formulations containing Lactobacillus rhamnosus (L. rhamnosus) as an active pharmaceutical ingredient (API) in a water base and oil base gel, evaluated the probiotic stability in formulation to obtain an optimum formulation, and finally, investigated the antibacterial activities of that against two common hospital-associated multidrug-resistant pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Furthermore, the pharmaceutical aspects of the optimum formulation, including stability, homogeneity, spreadability, pH value, conductivity, and rheological behavior, were assessed.The results indicated that the optimum formulation based on glycerol exhibited desirable pharmaceutical properties, including long-term stability, a perfect level of homogeneity, an acceptable range of spreadability with pseudo-plastic thixotropic behavior, and a promising antibacterial potential against MRSA and VRE. Our findings indicate that this novel probiotic formulation could be an excellent candidate to cope with antibiotic-resistant species, representing a hopeful treatment potential for topical applications, particularly in incurable infections. However, further in vivo studies seem warranted to evaluate their bactericidal activity against multi-drug resistant microorganisms.

The role of probiotics in tissue engineering and regenerative medicine

Tissue engineering and regenerative medicine (TERM) as an emerging field is a multidisciplinary science and combines basic sciences such as biomaterials science, biology, genetics and medical sciences to achieve functional TERM-based products to regenerate or replace damaged or diseased tissues or organs. Probiotics are useful microorganisms which have multiple effective functions on human health. They have some immunomodulatory and biocompatibility effects and improve wound healing. In this article, we describe the latest findings on probiotics and their pro-healing properties on various body systems that are useable in regenerative medicine. Therefore, this review presents a new perspective on the therapeutic potential of probiotics for TERM.

The Potential Value of Probiotics after Dental Implant Placement

Dental implantation is currently the optimal solution for tooth loss. However, the health and stability of dental implants have emerged as global public health concerns. Dental implant placement, healing of the surgical site, osseointegration, stability of bone tissues, and prevention of peri-implant diseases are challenges faced in achieving the long-term health and stability of implants. These have been ongoing concerns in the field of oral implantation. Probiotics, as beneficial microorganisms, play a significant role in the body by inhibiting pathogens, promoting bone tissue homeostasis, and facilitating tissue regeneration, modulating immune-inflammatory levels. This review explores the potential of probiotics in addressing post-implantation challenges. We summarize the existing research regarding the importance of probiotics in managing dental implant health and advocate for further research into their potential applications.

The ameliorating effect of limosilactobacillus fermentum and its supernatant postbiotic on cisplatin-induced chronic kidney disease in an animal model

BACKGROUND

Chronic kidney disease (CKD) is a worldwide public health problem affecting millions of people. Probiotics and postbiotics are associated with valuable compounds with antibacterial, anti-inflammatory, and immunomodulatory effects, preserving renal function in CKD patients. The current study is aimed to evaluate the efficacy of Limosilactobacillus fermentum (L. fermentum) and its postbiotic in an animal model of cisplatin-induced CKD.

METHODS

The animals were divided into four experimental groups (normal mice, CKD mice with no treatment, CKD mice with probiotic treatment, and CKD mice with postbiotic treatment). CKD mice were induced by a single dose of cisplatin 10 mg/kg, intraperitoneally. For 28 days, the cultured probiotic bacteria and its supernatant (postbiotic) were delivered freshly to the related groups through their daily water. Then, blood urea nitrogen (BUN) and creatinine (Cr) of plasma samples as well as glutathione (GSH), lipid peroxidation, reactive oxygen species, and total antioxidant capacity of kidneys were assessed in the experimental mice groups. In addition, histopathological studies were performed on the kidneys.

RESULTS

Application of L. fermentum probiotic, and especially postbiotics, significantly decreased BUN and Cr (P < 0.0001) as well as ROS formation and lipid peroxidation levels (P < 0.0001) along with increased total antioxidant capacity and GSH levels (P < 0.001). The histopathologic images also confirmed their renal protection effect. Interestingly, the postbiotic displayed more effectiveness than the probiotic in some assays. The improvement effect on renal function in the current model is mainly mediated by oxidative stress markers in the renal tissue.

CONCLUSIONS

In conclusion, it was found that the administration of L. fermentum probiotic, and particularly its postbiotic in cisplatin-induced CKD mice, showed promising effects and could successfully improve renal function in the animal model of CKD. Therefore, probiotics and postbiotics are considered as probably promising alternative supplements to be used for CKD.

Development and Characterization of Hydroxyethyl Cellulose-Based Gels Containing Lactobacilli Strains: Evaluation of Antimicrobial Effects in In Vitro and Ex Vivo Models

This study aimed to develop a hydroxyethyl cellulose-based topical formulation containing probiotics and to evaluate its antimicrobial action using in vivo and ex vivo models. Initially, the antagonistic effects of Lacticaseibacillus rhamnosus ATCC 10863, Limosilactobacillus fermentum ATCC 23271, Lactiplantibacillus plantarum ATCC 8014 and Lactiplantibacillus plantarum LP-G18-A11 were analyzed against Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae ATCC 700603, Staphylococcus aureus ATCC 27853 and Pseudomonas aeruginosa ATCC 2785. The best action was seen for L. plantarum LP-G18-A11, which presented high inhibition against S. aureus and P. aeruginosa. Then, lactobacilli strains were incorporated into hydroxyethyl cellulose-based gels (natrosol); however, only the LP-G18-A11-incorporated gels (5% and 3%) showed antimicrobial effects. The LP-G18-A11 gel (5%) maintained its antimicrobial effects and viability up to 14 and 90 days at 25 °C and 4 °C, respectively. In the ex vivo assay using porcine skin, the LP-G18-A11 gel (5%) significantly reduced the skin loads of S. aureus and P. aeruginosa after 24 h, while only P. aeruginosa was reduced after 72 h. Moreover, the LP-G18-A11 gel (5%) showed stability in the preliminary and accelerated assays. Taken together, the results show the antimicrobial potential of L. plantarum LP-G18-A11, which may be applied in the development of new dressings for the treatment of infected wounds.

Novel polycaprolactone (PCL)-type I collagen core-shell electrospun nanofibers for wound healing applications

Type I collagen (Col_1) is one of the main proteins present in the skin extracellular matrix, serving as support for skin regeneration and maturation in its granulation stage. Electrospun materials have been intensively studied as the next generation of skin wound dressing mainly due to their high surface area and fibrous porosity. However, the electrospinning of collagen-based solutions causes degradation of its structure. In this work, a coaxial electrospinning process was proposed to overcome this limitation. The production of mats of polycaprolactone (PCL)-Col_1/PVA (collagen/poly(vinyl alcohol)) composed of core-shell nanofibers was investigated. PCL solution was used as the core solution, while Col_1/PVA was used as the shell solution. PVA was used to improve the processability of collagen, while PCL was employed to improve the mechanical properties and morphology of Col_1/PVA fibers. The morphology and the cytotoxicity of the fibers were highly dependent on the processing parameters. Defect-free core-shell nanofibers were obtained with a shell/core flow rates ratio = 4, flight distance of 12 cm, and an applied voltage of 16 kV. Using this strategy, the triple helix structure characteristic of the collagen molecule was preserved. Moreover, the common post-processing of solvent removal could be suppressed, simplifying the manufacturing processing of these biomaterials. The nanostructured mats showed no cytotoxicity, high liquid absorption, structural stability, hydrophilic character, and collagen release capacity, making them a potential novel dressing for skin damage regeneration, in special in the case of chronic wounds treatment, in which exogenous collagen delivery is necessary.

Cellulose nanofibrils reinforced chitosan-gelatin based hydrogel loaded with nanoemulsion of oregano essential oil for diabetic wound healing assisted by low level laser therapy

Diabetic foot ulcers are imperfections in the process of wound healing due to hyperglycemic conditions. Here, a nanoemulgel fabricated with oregano essential oil nanoemulsion, assisted by low-level laser therapy, was investigated for its efficacy in diabetic wound healing. A hydrogel- based healing patch, fabricated using biological polymers namely chitosan and gelatin and, polyvinyl pyrollidone. The hydrogel was reinforced with cellulose nanofibrils for enhanced stability and barrier properties. Nanoemulsion of oregano essential oil, with an average particle size of 293.7 ± 8.3 nm, was prepared via homogenization with chitosan as the coating agent. Nanoemulsion impregnated hydrogel, termed as the nanoemulgel, was assessed for its physio-mechanical properties and healing efficiency. The strong linkages in nanoemulgel demonstrated its large swelling capacity, high mechanical strength, and maximum thermal stability. The optimized conditions for low-level laser therapy using 808 nm were 1 W. cm^-2 and 5 min. The optimized drug concentration of 128 μg. mL^-1 exhibited viability of NIH/3 T3 fibroblasts as 75.5 ± 1.2 % after 24 h. Cell migration assay demonstrated that dual therapy facilitated wound healing, with a maximum closure rate of 100 % at 48 h. In vivo results revealed the rapid healing effects of the dual therapy in diabetic rat models with foot ulcers: a maximum healing rate of 97.5 %, minimum scar formation, increased granulation, enhanced reepithelialization, and a drastic decrease in inflammation and neutrophil infiltration within the treatment period compared to monotherapy and control. In summary, the combinatorial therapy of nanoemulgel and low-level laser therapy is a promising regimen for managing diabetic foot ulcers with a rapid healing effect.

Role of wound microbiome, strategies of microbiota delivery system and clinical management

Delayed wound healing is one of the most global public health threats affecting nearly 100 million people each year, particularly the chronic wounds. Many confounding factors such as aging, diabetic disease, medication, peripheral neuropathy, immunocompromises or arterial and venous insufficiency hyperglycaemia are considered to inhibit wound healing. Therapeutic approaches for slow wound healing include anti-infection, debridement and the use of various wound dressings. However, the current clinical outcomes are still unsatisfied. In this review, we discuss the role of skin and wound commensal microbiota in the different healing stages, including inflammation, cell proliferation, re-epithelialization and remodelling phase, followed by multiple immune cell responses to commensal microbiota. Current clinical management in treating surgical wounds and chronic wounds was also reviewed together with potential controlled delivery systems which may be utilized in the future for the topical administration of probiotics and microbiomes. This review aims to introduce advances, novel strategies, and pioneer ideas in regulating the wound microbiome and the design of controlled delivery systems.

Immunomodulating Hydrogels as Stealth Platform for Drug Delivery Applications

Non-targeted persistent immune activation or suppression by different drug delivery platforms can cause adverse and chronic physiological effects including cancer and arthritis. Therefore, non-toxic materials that do not trigger an immunogenic response during delivery are crucial for safe and effective in vivo treatment. Hydrogels are excellent candidates that can be engineered to control immune responses by modulating biomolecule release/adsorption, improving regeneration of lymphoid tissues, and enhancing function during antigen presentation. This review discusses the aspects of hydrogel-based systems used as drug delivery platforms for various diseases. A detailed investigation on different immunomodulation strategies for various delivery options and deliberate upon the outlook of such drug delivery platforms are conducted.

A Functionalized Membrane Layer as Part of a Dressing to Aid Wound Healing

PURPOSE

This study is an approach to a dressing platform based on support functionalized with oxygenating factors within an alginate layer, constituting a safe and even contact surface for interface with a wound.

METHODS

An alginate layer with incorporated oxygenating elements deposited on the support patch was assessed. As an oxygenating factor, perfluorooctyl was applied, and the layer coatings in two options, cross-linked and not, were evaluated. The function of human dermal fibroblast cells cultured in the presence of these constructs was analyzed, as well as their morphology using flow cytometry, fluorescence microscopy, and scanning electron microscopy. In addition, the membrane coating material was assessed using FTIR, AFM, and SEM-EDX characterization.

RESULTS

The applied membrane coatings adsorbed on the patch ensured the viability of the human fibroblasts cultured on the membranes during 10 days of culture. However, on the sixth day of culture, the percentage of live cells grown in the presence of cross-linked alginate with oxygenating factor ((ALG-PFC)net) was significantly higher than that of the cells cultured in the presence of the alginate coatings alone. SEM-EDX analysis of the (ALG-PFC)_net confirmed the presence of oxygenating and cross-linking factors. In addition, the regular granular branched structure of the layer coating material involving the oxygenating and cross-linking factors was observed using the AFM technique.

CONCLUSION

The topography of the layer coating material involving the oxygenating and cross-linking factors ensures an even contact surface for interface with the wound. Considering 5-day intervals between dressing replacements, the platform with an oxygenating configuration ensuring the growth and morphology of the human fibroblasts can be recommended at this time as an element of a dressing system.

The ameliorative role of specific probiotic combinations on bone loss in the ovariectomized rat model

Background

Osteoporosis, a skeletal disease described by impaired bone strength, cause an increased risk of fractures. We aimed in this study to clarify which particular wise combination of probiotics has the most beneficial effect in the rat model of osteoporosis.

Methods

Sixty-three mature female Sprague Dawley rats (12–14 weeks old, weight 200 ± 20 g) were ovariectomized and then divided into nine random groups, each group consisting of 7 rats. Lactic acid bacteria were isolated from traditional fermented yogurt on the northern coast of the Persian Gulf. Seven combinations of probiotics, each containing three probiotic strains, were designed and administered (1 × 10 9 CFU / ml/strain daily along with their water) to treat ovariectomized rats. The period from ovariectomy to eutanásia was 3 months. For evaluating femur, spine, and tibia, bone mineral density (BMD), and bone mineral content (BMC), Dual-energy X-ray absorptiometry (DEXA) scans were performed. Also, effect of probiotic combinations was assessed on biochemical markers including vitamin D, calcium, phosphorus, and alkaline phosphatase in serum.

Results

Combination NO 4, containing L. acidophilus, B. longum, and L. reuteri, is the most influential group on global, spine, and femur BMD. Combination NO 3, containing L. acidophilus, L. casei, and L. reuteri, also significantly affects the BMD of the tibia among the treatment group. We found that the combination NO 4 had the most significant ameliorative effect on global BMC. Also, combination NO 1 (comprising L. acidophilus, L. casei, and B. longum), NO 6 (containing L. casei, B. longum, and Bacillus coagulans), NO 7 (containing L. casei, L. reuteri, and B. longum), and NO 4 had the most considerable raising effect on spine BMC. In addition, the serum calcium and Vitamin D concentration in the groups NO 4, 6, and 7 were significantly higher than in OVX groups, whereas the alkaline phosphatase concentration was considerably reduced in these groups.

Conclusion

Among nine effective probiotics, a combination containing L. acidophilus, B. longum, and L. reuteri is the most influential group in ovariectomized osteoporotic rat.

Recent advances in antiviral effects of probiotics: potential mechanism study in prevention and treatment of SARS-CoV-2

SARS-CoV-2 is responsible for coronavirus disease 2019 (COVID-19), progressively extended worldwide countries on an epidemic scale. Along with all the drug treatments suggested to date, currently, there are no approved management protocols and treatment regimens for SARS-CoV-2. The unavailability of optimal medication and effective vaccines against SARS-CoV-2 indicates the requirement for alternative therapies. Probiotics are living organisms that deliberate beneficial effects on the host when used sufficiently and in adequate amounts, and fermented food is their rich source. Probiotics affect viruses by antiviral mechanisms and reduce diarrhea and respiratory tract infection. At this point, we comprehensively evaluated the antiviral effects of probiotics and their mechanism with a particular focus on SARS-CoV-2. In this review, we suggested the conceptual and potential mechanisms of probiotics by which they could exhibit antiviral properties against SARS-CoV-2, according to the previous evidence concerning the mechanism of antiviral effects of probiotics. This study reviewed recent studies that speculate about the role of probiotics in the prevention of the SARS-CoV-2-induced cytokine storm through the mechanisms such as induction of anti-inflammatory cytokines (IL-10), downregulation of pro-inflammatory cytokines (TNF-α, IL-2, IL-6), inhibition of JAK signaling pathway, and act as HDAC inhibitor. Also, the recent clinical trials and their outcome have been reviewed.

Limosilactobacillus fermentum from buffalo milk is suitable for potential biotechnological process development and inhibits Helicobacter pylori in a gastric epithelial cell model

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L.fermentum from buffalo milk grows efficiently without animal-derived medium components.

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Highest viable biomass titers can be reached after only 8h improving productivity.

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L. fermentum is suitable for large scale production: complete biotech approach.

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L. fermentum demonstrates 60% cell survival after spray drying.

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L. fermentum from buffalo milk displaces H. pylori in a gastric epithelial cell model.

Probiotics are living microorganisms that give beneficial health effects while consumed, and each strain possesses diverse and unique properties and also different technological characteristics that affect its ability to be produced at large scale. Limosilactobacillus fermentum is a widely studied member of probiotics, however, few data are available on the development of fermentation and downstream processes for the production of viable biomasses for potential industrial applications.

In the present study a novel L. fermentum strain was isolated from buffalo milk and used as test example for biotechnological process development. The strain was able to produce up to 10⁹ CFU/mL on a (glucose based) semi-defined medium deprived of animal-derived raw materials up to the pilot scale (150 L), demonstrating improved results compared to commonly used, although industrially not suitable, media rich of casein and beef extract. The study of strain behavior in batch experiments indicated that the highest concentration of viable cells was reached after only 8 h of growth, greatly shortening the process. Moreover, initial concentrations of glucose in the medium above 30 g/L, if not supported by higher nitrogen concentrations, reduced the yield of biomass and increased production of heterolactic fermentation by-products. Biomass concentration via microfiltration on hollow fibers, and subsequent spray-drying allowed to recover about 5.7 × 10¹⁰CFU/g_powder of viable cells, indicating strain resistance to harsh processing conditions.

Overall, these data demonstrate the possibility to obtain and maintain adequate levels of viable L. fermentum cells by using a simple approach that is potentially suitable for industrial development. Moreover, since often exopolysaccharides produced by lactobacilli contribute to the strain's functionality, a partial characterization of the EPS produced by the newly identified L. fermentum strain was carried out.

Finally, the effect of L. fermentum versus H. pylori in a gastric epithelial cell model was evaluated demonstrating its ability to stimulate the response of the immune system and displace the infective agent.

Overview of the angiogenic effect of probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus) at human umbilical vein endothelial cells

Introduction: Angiogenesis (neovascularization), which means new vessel construction, is normal and physiologically, wound healing, embryogenesis, a necessary menstrual cycle it's a mechanism. When taken in appropriate amounts together with or separately with nutrients, mucosal and by regulating systemic immunity, ensuring nutritional and microbial balance in the intestines living nonpatogenic microorganisms that positively affect the health of the host it is called "probiotics". Lactic acid bacteria, the most probiotic microorganisms it constitutes its important group. Where probiotics have an effect on angiogenesis, and it is thought to help heal wounds through the road. With this research indicated that roles of Lactobacillus acidophilus and Lactobacillus rhamnosus on angiogenesis if present to demonstrate in vitro methods and the gene expression responsible for the formation of these effects it is intended to reveal. Material and Method: This study is an experimental study conducted in vitro human umbilical cord vein endothelial cell (HUVEC) MTT test in cell culture with (3-[4,5-Dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide; Thiazolyl blue) evaluation of viability and proliferation wound healing model, tube formation method and gene expression with real rime-polymer chain reaction (RT-PCR) methods of appointment were used. Results: HUVEC cells L. acidophilus 10⁹ CFU\ml after extract application statistical of mRNA expression of VEGF and FGF genes by control group 24 per hour it was found to increase significantly. L. rhamnosus 10 6 CFU\ml and 109 CFU\ml after application of extracts VEGF gene mRNA by control group 24 per hour its expression was found to be statistically significantly increased. Also L. rhamnosus extracts cell proliferation and migration of in vitro wound model it was found to increase statistically significantly. Conclusion: In this study, in vitro L. acidophilus 10⁹ CFU\ml extract and 10⁶ CFU\ml and 10⁹ CFU\ml extract of L. rhamnosus, VEGF gene mRNA revealed to be effective on angiogenesis in HUVEC cells by increasing expression it is.

Prevention of Postsurgical Abdominal Adhesion Using Electrospun TPU Nanofibers in Rat Model

Intra-abdominal adhesions following surgery are a challenging problem in surgical practice. This study fabricated different thermoplastic polyurethane (TPU) nanofibers with different average diameters using the electrospinning method. The conditions were evaluated by scanning electron microscopy (SEM), atomic force microscope (AFM), and Fourier transform infrared spectrometer (FTIR) analysis. A static tensile test was applied using a strength testing device to assess the mechanical properties of the electrospun scaffolds. By changing the effective electrospinning parameters, the best quality of nanofibers could be achieved with the lowest bead numbers. The electrospun nanofibers were evaluated in vivo using a rat cecal abrasion model. The macroscopic evaluation and the microscopic study, including the degree of adhesion and inflammation, were investigated after three and five weeks. The resultant electrospun TPU nanofibers had diameters ranging from about 200 to 1000 nm. The diameters and morphology of the nanofibers were significantly affected by the concentration of polymer. Uniform TPU nanofibers without beads could be prepared by electrospinning through reasonable control of the process concentration. These nanofibers' biodegradability and antibacterial properties were investigated by weight loss measurement and microdilution methods, respectively. The purpose of this study was to provide electrospun nanofibers having biodegradability and antibacterial properties that prevent any adhesions or inflammation after pelvic and abdominal surgeries. The in vivo experiments revealed that electrospun TPU nanofibers reduced the degree of abdominal adhesions. The histopathological study confirmed only a small extent of inflammatory cell infiltration in the 8% and 10% TPU. Conclusively, nanofibers containing 8% TPU significantly decreased the incidence and severity of postsurgical adhesions, and it is expected to be used in clinical applications in the future.

Investigation of the Effect of Nanocrystalline Calcium Carbonate-Substituted Hydroxyapatite and L-Lysine and L-Arginine Surface Interactions on the Molecular Properties of Dental Biomimetic Composites

Differences in the surface interactions of non-stoichiometric nanocrystalline B-type carbonate-substituted hydroxyapatite (n-cHAp) with the amino acids L-Lysine hydrochloride (L-LysHCl) and L-Arginine hydrochloride (L-ArgHCl) in acidic and alkaline media were determined using structural and spectroscopic analysis methods. The obtained data confirm that hydroxyapatite synthesized using our technique, which was used to develop the n-cHAp/L-LysHCl and n-cHAp/L-ArgHCl composites, is nanocrystalline. Studies of molecular composition of the samples by Fourier transform infrared spectroscopy under the change in the charge state of L-Lysine in environments with different alkalinity are consistent with the results of X-ray diffraction analysis, as evidenced by the redistribution of the modes' intensities in the spectra that is correlated with the side chains, i.e., amide and carboxyl groups, of the amino acid. During the formation of a biomimetic composite containing L-Lysine hydrochloride and n-cHAp, the interaction occurred through bonding of the L-Lysine side chain and the hydroxyl groups of hydroxyapatite, which created an anionic form of L-Lysine at pH ≤ 5. In contrast, in biocomposites based on L-Arginine and n-cHAp, the interaction only slightly depends on pH value, and it proceeds by molecular orientation mechanisms. The X-ray diffraction and infrared spectroscopy results confirm that changes in the molecular composition of n-cHAp/L-ArgHCl biomimetic composites are caused by the electrostatic interaction between the L-ArgHCl molecule and the carbonate-substituted calcium hydroxyapatite. In this case, the bond formation was detected by Fourier transform infrared (FTIR) spectroscopy; the vibrational modes attributed to the main carbon chain and the guanidine group of L-Arginine are shifted during the interaction. The discovered interaction mechanisms between nanocrystalline carbonate-substituted hydroxyapatite that has physicochemical properties characteristic of the apatite in human dental enamel and specific amino acids are important for selecting the formation conditions of biomimetic composites and their integration with the natural dental tissue.

A Novel Effective Formulation of Bioactive Compounds for Wound Healing: Preparation, In Vivo Characterization, and Comparison of Various Postbiotics Cold Creams in a Rat Model

The wound is a break in the integrity of the skin produced by injury, illness, or operation. Wound healing is an essential dynamic biological/physiological process that occurs in response to tissue damage. The huge health, economic, and social effects of wounds on patients and societies necessitate the research to find novel potential therapeutic agents in order to promote wound healing. Postbiotics, the newest member of the biotics family, are valuable functional bioactive substances produced by probiotics through their metabolic activity, which have several beneficial properties, including immunomodulatory, anti-inflammatory, antimicrobial, and angiogenesis characteristics, resulting in acceleration of wound healing. In the current study, three topical cold cream formulations containing postbiotics obtained from Lactobacillus fermentum, Lactobacillus reuteri, or Bacillus subtilis sp. natto probiotic strains were prepared. The effectiveness and wound healing activity of the developed postbiotics cold cream formulations were investigated compared to cold cream without postbiotics and no treatment via wound closure investigation, hydroxyproline content assay, and histological assessment in 25 Sprague Dawley rats divided into five groups. Interestingly, analysis of the results revealed that all three formulations containing postbiotics significantly accelerated the wound healing process. However, in general, the Bacillus subtilis natto cold cream manifested a better wound healing property. The pleasing wound healing characteristics of the topical postbiotics cold creams through the in vivo experiment suggest that formulations containing postbiotics can be considered as a promising nominee for wound healing approaches.

Insight Into the Beneficial Role of Lactiplantibacillus plantarum Supernatant Against Bacterial Infections, Oxidative Stress, and Wound Healing in A549 Cells and BALB/c Mice

Lactiplantibacillus plantarum MTCC 2621 is a well-characterized probiotic strain and is reported to possess many health benefits. However, the wound healing potential of this probiotic is yet to be explored. Here, we have assessed the antibacterial, antioxidant, and wound healing activities of cell-free supernatant of Lactiplantibacillus plantarum MTCC 2621 (Lp2621). Lp2621 exhibited excellent antibacterial activity against the indicator bacteria in the agar well diffusion assay. Lp2621 did not show any hemolytic activity. The safety of Lp2621 gel was established using the skin irritation assay in BALB/c mice, and no dermal reactions were observed. The supernatant showed 60–100% protection of A549 cells against H₂O₂-induced stress. In the scratch assay, Lp2621 accelerated wound healing after 24 h of treatment. The percent wound healing was significantly higher in cells treated with Lp2621 at 18–24 h posttreatment. In an excision wound healing in mice, topical application of Lp2621 gel showed faster healing than the vehicle- and betadine-treated groups. Similar wound healing activity was observed in wounds infected with Staphylococcus aureus. Histological examination revealed better wound healing in Lp2621-treated mice. Topical treatment of the wounds with Lp2621 gel resulted in the upregulation of pro-inflammatory cytokine IL-6 in the early phase of wound healing and enhanced IL-10 expression in the later phase. These findings unveil a protective role of Lp2621 against bacterial infection, oxidative stress, and wound healing.

Latest developments in food-grade delivery systems for probiotics: A systematic review

Tremendous progress in the inseparable relationships between probiotics and human health has enabled advances in probiotic functional foods. To ensure the vitality of sensitive probiotics against multiple harsh conditions, rising food-grade delivery systems for probiotics have been developed. This review gives a summary of recently reported delivery vehicles for probiotics, analyzes their respective merits and drawbacks and makes comparisons among them. Subsequently, the applications and future prospects are discussed. According to the types of encapsulating probiotics, food-grade delivery systems for probiotics can be classified into "silkworm cocoons" and "spider webs", which are put forward in this paper. The former, which surrounds the inner probiotics with the outer protective layers, includes particles, emulsions, beads, hybrid electrospun nanofibers and microcapsules. While hydrogels and bigels belong to the latter, which protects probiotics with the aid of network structures. The future prospects include preferable viability and stability of probiotics, co-delivery systems, targeted gut release of probiotics, delivery of multiple strains, more scientific experimental verification and more diversified food products, which will enlighten further studies on delivering probiotics for human health. Taken together, delivery vehicles for probiotics are-or will soon be-in the field of food science, with further applications under development.

Biomimetic Hydrogels to Promote Wound Healing

Wound healing is a common physiological process which consists of a sequence of molecular and cellular events that occur following the onset of a tissue lesion in order to reconstitute barrier between body and external environment. The inherent properties of hydrogels allow the damaged tissue to heal by supporting a hydrated environment which has long been explored in wound management to aid in autolytic debridement. However, chronic non-healing wounds require added therapeutic features that can be achieved by incorporation of biomolecules and supporting cells to promote faster and better healing outcomes. In recent decades, numerous hydrogels have been developed and modified to match the time scale for distinct stages of wound healing. This review will discuss the effects of various types of hydrogels on wound pathophysiology, as well as the ideal characteristics of hydrogels for wound healing, crosslinking mechanism, fabrication techniques and design considerations of hydrogel engineering. Finally, several challenges related to adopting hydrogels to promote wound healing and future perspectives are discussed.

Exploring the bone sparing effects of postbiotics in the post-menopausal rat model

Background

Post-menopausal osteoporosis is a concern of health organizations, and current treatments do not seem enough. Postbiotics as bioactive compounds produced by probiotics may be an attractive alternative for bone health. In this study, we prepared, formulated, and compared the effects of cell lysate and supernatant of five native probiotic strains (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei, Bifidobacterium longum, and Bacillus coagulans) in ovariectomized (OVX) rats.

Methods

The probiotic strains were isolated, and their cell-free supernatants and biomasses as postbiotics were extracted and formulated using standard microbial processes. The Sprague-Dawley rats were fed by 1 × 10⁹ CFU/ml/day postbiotic preparations for 4 weeks immediately after ovariectomy. Dual-energy X-ray absorptiometry (DEXA) scans were accomplished to evaluate femur, spine, and tibia BMD. The serum biochemical markers [calcium, phosphorus, and alkaline phosphatase] were assessed.

Results

Postbiotics could considerably improve the global and femur area in OVX rats. In the case of global bone mineral density (BMD), Lactobacillus casei lysate and supernatant, Bacillus coagulans lysate and supernatant, lysate of Bifidobacterium longum and Lactobacillus acidophilus, and Lactobacillus reuteri supernatant significantly increased BMD. We found Bacillus coagulans supernatant meaningfully enriched tibia BMD.

Conclusion

Postbiotic could ameliorate bone loss resulting from estrogen deficiency. Also, the effects of postbiotics on different bone sites are strain-dependent. More clinical studies need to explore the optimal administrative dose and duration of the specific postbiotics in protecting bone loss.