Glucan stimulates human dermal fibroblast collagen biosynthesis through a nuclear factor-1 dependent mechanism

Antimicrobial Nano-Zinc Oxide Biocomposites for Wound Healing Applications: A Review

Chronic wounds are a major concern for global health, affecting millions of individuals worldwide. As their occurrence is correlated with age and age-related comorbidities, their incidence in the population is set to increase in the forthcoming years. This burden is further worsened by the rise of antimicrobial resistance (AMR), which causes wound infections that are increasingly hard to treat with current antibiotics. Antimicrobial bionanocomposites are an emerging class of materials that combine the biocompatibility and tissue-mimicking properties of biomacromolecules with the antimicrobial activity of metal or metal oxide nanoparticles. Among these nanostructured agents, zinc oxide (ZnO) is one of the most promising for its microbicidal effects and its anti-inflammatory properties, and as a source of essential zinc ions. This review analyses the most recent developments in the field of nano-ZnO–bionanocomposite (nZnO-BNC) materials—mainly in the form of films, but also hydrogel or electrospun bandages—from the different preparation techniques to their properties and antibacterial and wound-healing performances. The effect of nanostructured ZnO on the mechanical, water and gas barrier, swelling, optical, thermal, water affinity, and drug-release properties are examined and linked to the preparation methods. Antimicrobial assays over a wide range of bacterial strains are extensively surveyed, and wound-healing studies are finally considered to provide a comprehensive assessment framework. While early results are promising, a systematic and standardised testing procedure for the comparison of antibacterial properties is still lacking, partly because of a not-yet fully understood antimicrobial mechanism. This work, therefore, allowed, on one hand, the determination of the best strategies for the design, engineering, and application of n-ZnO-BNC, and, on the other hand, the identification of the current challenges and opportunities for future research.

β-1,4-Galactan suppresses lipid synthesis in sebaceous gland cells via TLR4

Sebum is a lipid mixture secreted from sebaceous glands of the skin. The excessive secretion of sebum causes acne vulgaris and seborrheic dermatitis, while its deficiency causes xerosis. Therefore, the appropriate control of sebum secretion is crucially important to keep the skin healthy. In the present study, we evaluated the effects of naturally occurring polysaccharides on lipid biosynthesis in hamster sebaceous gland cells. Among the tested polysaccharides, β-1,4-galactan, the main chain of type I arabinogalactan, most potently suppressed lipid synthesis in the sebaceous gland cells as analysed by oil red O staining. Toll-like receptor (TLR)4 inhibitors counteracted this suppressive effect and lipopolysaccharide, a TLR4 ligand, mimicked this effect, suggesting the involvement of the TLR4 signalling pathway. In the cells β-1,4-galactan significantly decreased mRNA levels of lipogenesis-related transcription factors (peroxisomeGraphical Abstract$\includegraphics{\bwartpath }$ proliferator-activated receptor γ and sterol regulatory element-binding protein 1) and enzymes (acetyl-CoA carboxylase and fatty acid synthase) as well as the glucose transporter GLUT4. Furthermore, β-1,4-galactan increased the production of lactic acid serving as a natural moisturizing factor and enhanced the proliferation of sebaceous gland cells. These results suggest potential of β-1,4-galactan as a material with therapeutic and cosmetic values for the skin.

Brown Algae Carbohydrates: Structures, Pharmaceutical Properties, and Research Challenges

Brown algae (Phaeophyceae) have been consumed by humans for hundreds of years. Current studies have shown that brown algae are rich sources of bioactive compounds with excellent nutritional value, and are considered functional foods with health benefits. Polysaccharides are the main constituents of brown algae; their diverse structures allow many unique physical and chemical properties that help to moderate a wide range of biological activities, including immunomodulation, antibacterial, antioxidant, prebiotic, antihypertensive, antidiabetic, antitumor, and anticoagulant activities. In this review, we focus on the major polysaccharide components in brown algae: the alginate, laminarin, and fucoidan. We explore how their structure leads to their health benefits, and their application prospects in functional foods and pharmaceuticals. Finally, we summarize the latest developments in applied research on brown algae polysaccharides.

Extraction and characterization of an exopolysaccharide from a marine bacterium

The marine bacterial exopolysaccharides (EPS) have transfigured the biotech sector with their myriad applications and prospects. This work was carried out to characterize and analyze the functional and biochemical properties of an EPS (EPS-DR3A) produced by a marine bacterium, Pseudoalteromonas sp. YU16-DR3A. The bacterium was cultured in Zobell marine broth for the production of EPS. The extracted EPS designated as EPS-DR3A was composed of 69% carbohydrates and 7.6% proteins with a molecular weight of 20 kDa. FT-IR spectra showed the presence of different functional groups. The monosaccharide analysis performed using GC-MS showed the presence of fucose, erythrotetrose, ribose, and glucose as monomers. EPS-DR3A showed excellent emulsifying activity against the tested hydrocarbons and food oils with stable emulsions. Rheological analysis of EPS-DR3A revealed the pseudoplastic behavior. The EPS-DR3A displayed good thermal stability with a degradation temperature of 249 °C and a melting point at 322 °C. Further, it had the ability to scavenge DPPH and nitric oxide free radicals with good total antioxidant activity. The in vitro biocompatibility study of EPS-DR3A showed high degree of biocompatibility with human dermal fibroblast cells at the tested concentrations. Taken together, the findings such as thermostability, emulsifying activity, pseudoplasticity, antioxidant activity, and biocompatibility of EPS-DR3A make this biomolecule an important candidate for a wide range of biomedical applications.

Probiotics for periodontal health-Current molecular findings

Dysbiosis of the oral microbiome is associated with a variety of oral and systemic diseases, including periodontal disease. Oral dysbiosis in periodontal disease leads to an exacerbated host immune response that induces progressive periodontal tissue destruction and ultimately tooth loss. To counter the disease‐associated dysbiosis of the oral cavity, strategies have been proposed to reestablish a “healthy” microbiome via the use of probiotics. This study reviews the literature on the use of probiotics for modifying the oral microbial composition toward a beneficial state that might alleviate disease progression. Four in vitro and 10 preclinical studies were included in the analysis, and these studies explored the effects of probiotics on cultured biofilm growth and bacterial gene expressions, as well as modulation of the host response to inflammation. The current molecular findings on probiotics provide fundamental evidence for further clinical research for the use of probiotics in periodontal therapy. They also point out an important caveat: Changing the biofilm composition might alter the normal oral flora that is beneficial and/or critical for oral health.

Hydrogel containing (1 → 6)-β-D-glucan (lasiodiplodan) effectively promotes dermal wound healing

A hydrogel containing exocellular (1 → 6)-β-D-glucan (lasiodiplodan, LAS) was developed and its wound healing potential was evaluated. β-Glucans have attracted much interest by the cosmetic industry sector because of their bioactive and functional properties and in promoting skin health. In the present work an β-glucan was studied as a healing biomaterial that has not hitherto been reported in the scientific literature. LAS produced by the ascomycete Lasiodiplodia theobromae MMPI was used in the formulation of a healing hydrogel. Physicochemical and microbiological quality parameters, antioxidant potential and stability of the formulation was evaluated. FTIR, thermal analysis and SEM techniques were also employed in the characterization. Wistar rats were used as a biological model to investigate the wound healing potential. Histological analyses of cutaneous tissue from the dorsal region were conducted after 4, 7, 10 and 14 days of treatment, and evaluated re-epithelialization, cell proliferation and collagen production. Physicochemical stability, microbiological quality and antioxidant potential, especially in relation to its ability to scavenge hydroxyl radicals were found. The hydrogel stimulated cell re-epithelialization and proliferation during all days of the treatment, and stimulated an increase of collagen fibers. Lasiodiplodan showed immunomodulatory activity in wound healing and this biomacromolecule could be an alternative compound in wound care.

Curdlan-Chitosan Electrospun Fibers as Potential Scaffolds for Bone Regeneration

Polysaccharides have received a lot of attention in biomedical research for their high potential as scaffolds owing to their unique biological properties. Fibrillar scaffolds made of chitosan demonstrated high promise in tissue engineering, especially for skin. As far as bone regeneration is concerned, curdlan (1,3-β-glucan) is particularly interesting as it enhances bone growth by helping mesenchymal stem cell adhesion, by favoring their differentiation into osteoblasts and by limiting the osteoclastic activity. Therefore, we aim to combine both chitosan and curdlan polysaccharides in a new scaffold for bone regeneration. For that purpose, curdlan was electrospun as a blend with chitosan into a fibrillar scaffold. We show that this novel scaffold is biodegradable (8% at two weeks), exhibits a good swelling behavior (350%) and is non-cytotoxic in vitro. In addition, the benefit of incorporating curdlan in the scaffold was demonstrated in a scratch assay that evidences the ability of curdlan to express its immunomodulatory properties by enhancing cell migration. Thus, these innovative electrospun curdlan–chitosan scaffolds show great potential for bone tissue engineering.

Synthesis, Characterization, and Biological Activity of Aminated Zymosan

Zymosan (ZM), a naturally occurring insoluble macromolecule obtained from the cell wall of Saccharomyces cerevisiae, is used as a functional food (as dietary fiber), phagocytic stimulus, and immune potentiator. The present study aimed to increase its solubility and evaluate its immunological application. ZM was converted into soluble 6-amino-6-deoxy-β-(1-3)-glucan of a molecular weight of 296 kDa by reduction. Detailed structural characterization of aminated ZM was determined by Fourier transform infrared spectroscopy and two-dimensional NMR analysis (2D, COSY, TOCSY, ROSEY, NOSEY, and HSQC). Aminated ZM was biocompatible with Raw 264.7 macrophage cell lines up to a concentration of 100 μg/mL. Rhodamine tagging revealed that the aminated ZM microparticles were found localized within the nucleus of Raw 264.7 cells. Both native and aminated ZM showed a similar expression pattern of inflammatory genes in Raw 264.7.

Laminarin Attenuates Ultraviolet-Induced Skin Damage by Reducing Superoxide Anion Levels and Increasing Endogenous Antioxidants in the Dorsal Skin of Mice

A number of studies have demonstrated that marine carbohydrates display anti-oxidant, anti-melanogenic, and anti-aging activities in the skin. Laminarin (LA), a low-molecular-weight polysaccharide, is found in brown algae. The benefits of LA in ultraviolet B (UVB) induced photodamage of the skin have not been reported. The aim of this study was to investigate the effects of pre-treated LA on histopathological changes and oxidative damage in mouse dorsal skin on day 5, following repeated UVB exposure. Histopathology, Western blot analysis and immunohistochemical studies showed that epidermal thickness in the UVB group was significantly increased; however, the thickness in the UVB group treated with LA (LA/UVB group) was less compared with that of the UVB group. Collagen fibers in the dermis of the UVB group were significantly decreased and destroyed, whereas, in the LA/UVB group, the density of collagen fibers was significantly increased compared with that of the UVB group. Oxidative stress due to superoxide anion production measured via dihydroethidium fluorescence staining was dramatically increased in the UVB group, whereas in the LA/UVB group, the oxidative stress was significantly decreased. Expressions of SOD1, glutathione peroxidase and catalase were markedly reduced in the UVB group, whereas in the LA/UVB group, they were significantly higher along with SOD2 than in the control group. Taken together, our results indicate that LA pretreatment prevents or attenuates skin damage, by decreasing oxidative stress and increasing antioxidant enzymes in mouse dorsal skin.

Isolation and Purification of Glucans from an Italian Cultivar of Ziziphus jujuba Mill. and In Vitro Effect on Skin Repair

Glucans possess a broad spectrum of biological activities. In this context, the present study was performed to isolate glucans from an Italian cultivar of Ziziphus jujuba Mill. at three different harvesting periods, in order to evaluate their effects on wound healing. The dry fruits were subjected to an alkaline extraction and then isolated glucans were purified by dialyzation. The crude and soluble samples were characterized by FT-IR and SEM analyses. Afterwards, total, α- and β-glucan content was measured using an enzymatic procedure. The results highlighted that the glucan amount increased as the maturation proceeded as well as the β-glucan percentage, which ranged from 48.2 at the first harvesting to 65.4 at the third harvesting. Furthermore, the effects of isolated glucans on the viability and migration of keratinocytes were evaluated using the in vitro MTT and scratch wound assays. The best proliferative effects on keratinocyte migration have been achieved with soluble glucans from third harvesting at 100 μM after 24 and 48 h (*** P < 0.001). The same treated group showed significant narrowing of the scratch area after 24 h and complete closure of the injury after 48 h. The findings highlighted the effectiveness of soluble glucans on regeneration of damaged skin.

β-Glucans: Multi-Functional Modulator of Wound Healing

β-glucans are derived from a variety of sources including yeast, grain and fungus and belong to the class of drugs known as biological response modifiers. They possess a broad spectrum of biological activities that enhance immunity in humans. One promising area for β-glucans’ application is dermatology, including wound care. Topical applications of β-glucans are increasing, especially due to their pluripotent properties. Macrophages, keratinocytes and fibroblasts are considered the main target cells of β-glucans during wound healing. β-glucans enhance wound repair by increasing the infiltration of macrophages, which stimulates tissue granulation, collagen deposition and reepithelialization. β-glucan wound dressings represent a suitable wound healing agent, with great stability and resistance to wound proteases. This review summarizes the current knowledge and progress made on characterizing β-glucans’ wound healing properties in vitro and in vivo and their safety and efficacy in managing non-healing wounds or other chronic dermatological conditions and diseases.

Engineering Tissues without the Use of a Synthetic Scaffold: A Twenty-Year History of the Self-Assembly Method

Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogenesis (LOEX), introduced the self-assembly technique. This innovative technique relies on the ability of dermal fibroblasts to produce and assemble their own extracellular matrix, differing from all other tissue-engineering techniques that use preformed synthetic scaffolds. Nevertheless, the use of the self-assembly technique was limited for a long time due to its main drawbacks: time and cost. Recent scientific breakthroughs have addressed these limitations. New protocol modifications that aim at increasing the rate of extracellular matrix formation have been proposed to reduce the production costs and laboratory handling time of engineered tissues. Moreover, the introduction of vascularization strategies in vitro permits the formation of capillary-like networks within reconstructed tissues. These optimization strategies enable the large-scale production of inexpensive native-like substitutes using the self-assembly technique. These substitutes can be used to reconstruct three-dimensional models free of exogenous materials for clinical and fundamental applications.

An investigation of konjac glucomannan-keratin hydrogel scaffold loaded with Avena sativa extracts for diabetic wound healing

We have developed a novel hydrogel composed of konjac glucomannan (KGM), human hair proteins (KER), and an ethanolic extract of Avena sativa (OAT) and evaluated its potential as a dressing material for diabetic wounds. KGM is an excellent biocompatible gelling agent that stimulates fibroblast proliferation and immunomodulation. Human hair proteins (KER) are biocompatible, biodegradable, and possess abundant cell adhesion sites. KER also promotes fibroblast attachment and proliferation, keratinocyte migration, and collagen expression, which can accelerate wound healing. OAT consists of oat β-glucans and several anti-inflammatory and antioxidant moieties that can reduce prolonged inflammation in chronic wounds. SEM images confirm the highly porous architecture of the scaffolds. When immersed in PBS, KGM+KER+OAT hydrogels absorb 7.5 times their dry weight. These hydrogels display a measured rate of degradation in lysozyme. KGM+KER+OAT hydrogels showed no significant cytotoxicity against NIH/3T3 fibroblasts. DAPI and SEM images obtained after 48h of cell culture illustrate the attachment and infiltration of fibroblasts. In vivo studies performed using a diabetic rat excision wound model showed that KGM+KER+OAT hydrogels significantly accelerated wound healing compared to the control and the KGM+KER hydrogels.

Effects of Lucilia sericata on wound healing in streptozotocin-induced diabetic rats and analysis of its secretome at the proteome level

The use of Lucilia sericata larvae on the healing of wounds in diabetics has been reported. However, the role of the excretion/secretion (ES) products of the larvae in treatment of diabetic wounds remains unknown. This study investigated whether application of the ES products of L. sericata on the wound surface could improve the impaired wound healing in streptozotocin-induced diabetic rats. Additional analysis was performed to understand proteome content of L. sericata secretome to understand ES contribution at the molecular level. For this purpose, full-thickness skin wounds were created on the backs of diabetic and control rats. A study was conducted to assess the levels of the ES-induced collagen I/III expression and to assay nuclear factor κB (NF-κB) (p65) activity in wound biopsies and ES-treated wounds of diabetic rat skin in comparison to the controls. The expression levels of collagen I/III and NF-κB (p65) activity were determined at days 3, 7, and 14 after wounding using immunohistological analyses and enzyme-linked immunosorbent assay technique. The results indicated that treatment with the ES extract increased collagen I expressions of the wound control and diabetic tissue. But the increase in collagen I expression in the controls was higher than the one in the diabetics. NF-κB (p65) activity was also increased in diabetic wounds compared to the controls, whereas it was decreased in third and seventh days upon ES treatment. The results indicated that ES products of L. sericata may enhance the process of wound healing by influencing phases such as inflammation, NF-κB (p65) activity, collagen synthesis, and wound contraction. These findings may provide new insights into understanding of therapeutic potential of ES in wound healing in diabetics.

Cyclic β-(1→3) (1→6) glucan/carrageenan hydrogels for wound healing applications

In the present study, cyclic β-(1→3) (1→6)glucan/carrageenan hydrogels (CBG/Car) were prepared and theirin vivowound healing potential in rats and their ability to encapsulate a hydrophobic drug, ciprofloxacin, were studied.

Arabinogalactan:β-glucan as novel biodegradable carriers for recombinant human thrombin

The aim of this work was to evaluate the effects of incorporating thrombin in arabinogalactan (AG)/β-glucan (BG)-based carriers. The products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy techniques. Results, especially deconvoluted XRPD patterns indicated creation of new phases and potential complex formation. Results also highlighted that the AG carrier leads to higher residual thrombin-specific activity, while the in vivo haemostatic effect was enhanced when insoluble BG was present in the matrix. Our results confirm that thrombin can be successfully added to the carriers and that these materials are promising alternatives to standard vehicles.

Effect of the probiotic Saccharomyces cerevisiae on ligature-induced periodontitis in rats

BACKGROUND AND OBJECTIVE

This study assessed the effects of the local use of Saccharomyces cerevisiae as monotherapy and as an adjuvant to the mechanical treatment of ligature-induced periodontitis in rats.

MATERIAL AND METHODS

Periodontitis was induced in 72 rats via the installation of a ligature around the mandibular first molar. After 7 d, the ligature was removed and the rats were placed in one of the following groups: no treatment (C; n = 18); scaling and root planing (SRP; n = 18); local irrigation with probiotics (PRO; n = 18); and SRP followed by local irrigation with probiotics (SRP/PRO; n = 18). Six rats from each group were killed at 7, 15 and 30 d. The histological characteristics, alveolar bone loss (ABL) and immunolabeling of tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), interleukin-10 (IL-10) and TRAP on the furcation area of the first molar were assessed.

RESULTS

The PRO group showed features of acceleration of the tissue-repair process during the entire experiment. On day 15, there was less ABL in the SRP/PRO group compared with the C group. There were fewer TRAP-positive cells in the SRP and SRP/PRO groups at 30 d. There was less immunostaining for TNF-α in the PRO and SRP/PRO groups and less immunostaining for IL-1β in the PRO group. However, there was more immunostaining for IL-10 in the PRO group on day 15.

CONCLUSION

Local use of the probiotic did not result in any adverse effects on periodontal tissues. When used as monotherapy or as an adjuvant, the probiotic was effective at controlling periodontitis in rats.

Role of seaweed laminaran from Saccharina longicruris on matrix deposition during dermal tissue-engineered production

Our laboratory has developed a technique to reconstruct in vitro tissue from human cells using the self-assembly tissue-engineering method, which utilizes the ability of fibroblasts to deposit the matrix they secrete. The time necessary for tissue construction, several weeks, is a drawback for many clinical uses. We hypothesized that the addition of laminaran can increase the deposition of matrix, speeding up the production of the tissue. Laminaran was isolated from the brown seaweed Saccharina longicruris harvested in Canada and its structure was evaluated. Laminaran is a small molecular weight polysaccharide composed of linear glucose chains. Monolayer-cultured human skin fibroblasts were cultured in the presence of laminaran with ascorbate for 7 or 35 days to produce a dermis. Treatment did not induce any variation in the growth rate or alpha smooth muscle actin content but it did increase the deposition of collagen I in a dose-dependent manner. After 35 days, the reconstructed dermal thickness was increased when laminaran was added, and collagen I deposition and MMP activity were also significantly increased. Thus, laminaran can be used to increase the rate of production of reconstructed self-assembled dermis and can also potentially be used in cosmetic or therapeutic creams to stimulate matrix production.

The Effect of Mushroom Beta-Glucans from Solid Culture of Ganoderma lucidum on Inhibition of the Primary Tumor Metastasis

This study evaluates the effect of mushroom beta-glucans (MBGS) derived from solid culture of Ganoderma lucidum on tumor inhibition by examining size of the primary tumor and rate of metastasis in Lewis lung carcinoma (LLC) bearing mice (C57BL/6), given oral administration of MBGS with radiation therapy. A previous result showed that MBGS enhances NK cell-mediated cytotoxicity in mice without LLC bearing in advance. Furthermore, applications of MBGS in conjunction with radiation therapy were effective in controlling tumor growth, and rate of metastasis, life threatening, and can potentially serve as a protective factor for wounds and hair loss that resulted from the overgrowth of primary tumor in LLC bearing mice.

Macrophage stimulating agent soluble yeast β-1,3/1,6-glucan as a topical treatment of diabetic foot and leg ulcers: A randomized, double blind, placebo-controlled phase II study

AIMS/INTRODUCTION

Dysregulated inflammatory response is believed to be an important factor in the pathogenesis of several late complications of diabetes mellitus. β-Glucans are potent inducers of immune function. The present randomized, double blind, two-center, placebo-controlled study was undertaken to explore safety, tolerability and efficacy of soluble β-1,3/1,6-glucan (SBG) as a local treatment of diabetic foot ulcers.

MATERIALS AND METHODS

A total of 60 patients with type 1 or 2 diabetes and lower extremity ulcers (Wagner grade 1-2, Ankle/Brachial Index ≥0.7) received SBG or a comparator product (methylcellulose) locally three times weekly up to 12 weeks in addition to conventional management scheme. A total of 54 patients completed the study.

RESULTS

A tendency for shorter median time to complete healing in the SBG group was observed (36 vs 63 days, P = 0.130). Weekly percentage reduction in ulcer size was significantly higher in the SBG group than in the methylcellulose group between weeks 1-2, 3-4 and 5-6 (P < 0.05). The proportion of ulcers healed by week 12 was also in favor of SBG (59% vs 37%, P = 0.09), with a significantly higher healing incidence in the SBG group at week 8 (44% vs 17%, P = 0.03). SBG was safe and well tolerated. There was a clinically significant difference regarding the incidence of serious adverse events in favor of the SBG treatment.

CONCLUSIONS

Local treatment of diabetic lower extremity ulcers with β-1,3/1,6-polyglucose shows good safety results. This β-glucan preparation shows promising potential as a treatment accelerating cutaneous healing. Further studies are required to confirm this effect. This trial was registered with ClinicalTrials.gov (no. NCT00288392).

β-glucan enriched bath directly stimulates the wound healing process in common carp (Cyprinus carpio L.)

Wound healing is a complex and well-organized process in which physiological factors and immune mechanisms are involved. A number of different immune modulators have been found to enhance the non-specific defence system in vertebrates, among which β-glucans are the most powerful and extensively investigated. The aim of the present study was to investigate the biological impact of two different commercially available β glucan containing products on the wound healing process in carp. Throughout a two week experiment fish were kept either untreated (control), or in water supplemented with the two different types of β-glucans. The wound healing process was monitored using a multispectral visualisation system. The correlation between wound closure and immune response was investigated by measuring the gene expression patterns of IL-1β, IL-6 family member M17, IL-8 and Muc5b, and measurement of production of radical oxygen species. PAMPs/DAMPs stimulation caused by the wounding and or β-glucans resulted in an inflammatory response by activating IL-1β, IL-6 family member M17 and IL-8 and differences in the expression pattern were seen depending on stimuli. IL-1β, IL-6 family member M17 and IL-8 were activated in all wounds regardless of treatment. Expression of all three interleukins was highly up regulated in control wounded muscle already at day 1 post-wounding and decreased at subsequent time-points. The reverse was the case with control wounded skin, where expression increased from day 1 through day 14. The results for the β-glucan treated wounds were more complex. The images showed significantly faster wound contraction in both treated groups compared to the control. The obtained results clearly demonstrated that a β glucan enriched bath promotes the closure of wounds in common carp and induce a local change in cytokine expression.

Case series of topical and orally administered β-glucan for the treatment of diabetic wounds: clinical study

BACKGROUND

Chronic, nonhealing wounds, foot ulcers, and lower extremity amputations are among the most problematic complications associated with diabetes mellitus. Standard care for diabetes-related chronic ulcers has included treatment of infection, weight off-loading, aggressive surgical débridement, and maintenance of a moist wound environment with frequent dressing changes.

OBJECTIVE

Yeast glucan is a particular high-molecular-weight polymer of β-(1,3)-glycosidic linkages of glycopyranose. We report our observations about the effectiveness of topically and orally administrated β-(1,3)-glucan for the treatment of chronic diabetic wounds and compare them to the literature results previously reported for similar wounds.

MATERIALS AND METHODS

Twenty-two patients with nonhealing ulcers associated with diabetes were included in this study. β-Glucan was given both orally and topically for the treatment of nonhealing ulcers. Macroscopic changes and surface areas of diabetic ulcers were recorded, and complete healing times were noted for each patient.

RESULTS

A rapid decrease in size and healthy granulation were significantly observed in most patients. The duration of complete healing averaged 10.8 weeks (range 6-20 weeks). No adverse events were observed in the treatment period. The complete healing time was shorter than the results previously reported in the literature.

CONCLUSIONS

Our observations support the view that application of glucan hastens epithelialization and wound closure, so topically and orally administered β-(1,3)-glucan therapy can help reverse some of the deficits in impaired healing diseases such as diabetes mellitus.

Soluble glucan is internalized and trafficked to the Golgi apparatus in macrophages via a clathrin-mediated, lipid raft-regulated mechanism

Glucans are natural product carbohydrates that stimulate immunity. Glucans are internalized by the pattern recognition receptor, Dectin-1. Glucans were thought to be trafficked to phagolysosomes, but this is unproven. We examined the internalization and trafficking of soluble glucans in macrophages. Incubation of macrophages with glucan resulted in internalization of Dectin-1 and glucan. Inhibition of clathrin blocked internalization of the Dectin-1/glucan complex. Lipid raft depletion resulted in decreased Dectin levels and glucan uptake. Once internalized, glucans colocalized with early endosomes at 0 to 15 min, with the Golgi apparatus at 15 min to 24 h, and with Dectin-1 immediately (0 h) and again later (15 min-24 h). Glucans did not colocalize with lysosomes at any time interval examined. We conclude that the internalization of Dectin-1/glucan complexes in macrophages is mediated by clathrin and negatively regulated by lipid rafts and/or caveolin-1. Upon internalization, soluble glucans are trafficked via endosomes to the Golgi apparatus, not lysosomes.

Microporous polysaccharide hemospheres and seroma formation after mastectomy and axillary dissection in rats

OBJECTIVE

Seroma is the most common complication after breast surgery. Several methods have been proposed to prevent seroma, but none of these provided a significant effect. A prolonged wound healing process is the most important cause of seroma. Microporous polysaccharide hemospheres (MPH) are used to achieve hemostasis. They may also accelerate wound healing. In this study, the effects of MPH on seroma formation were investigated.

MATERIAL AND METHODS

Female Wistar rats weighing between 200 g and 250 g were used. There were eight rats in each of the control and study groups. Right breast mastectomy and axillary dissection were performed in all rats. While no application was performed after the operation in the control group, MPH was locally applied to the surgical site in the study group. Ten days after the operation, seroma fluid was aspirated and the total volume was recorded. The aspirates were analyzed and tissue samples were obtained from the surgical site.

RESULTS

Seroma was significantly lower in the study group (p=0.001). The mean albumin and lactate dehydrogenase levels were significantly lower in the study group (p=0.003). Pathological examination revealed that increase in fibrous tissue was significantly greater in the control group (p=0.032).

CONCLUSION

MPH may reduce seroma after mastectomy.

Aminated β-1,3-D-glucan has a dose-dependent effect on wound healing in diabetic db/db mice

Inflammatory responses are common in diabetes and are operative in angiopathy, neuropathy, and wound healing. There are indications of incomplete macrophage activation in diabetes and reduced expression of growth factors. We have previously found that up to 15 topical applications of the macrophage-stimulant, aminated β-1,3-D-glucan (AG), improved wound healing in db/db mice. The present open-label study was undertaken to examine dose-dependent effects of AG over 40 days in db/db mice. AG was given as a single dose (group 1), one dose every 10th day (group 2), five initial doses on consecutive days (group 3), and ≥15 doses (group 4). Controls were db/db mice receiving platelet-derived growth factor + insulin-like growth factor-1 (group 5), topical placebo (NaCl 9 mg/mL) and insulin (group 6), placebo (group 7), and a nondiabetic group receiving placebo (group 8). Seven to 14 animals were allocated to each group. Percentage wound closure 17 days after surgery in groups 1 and 2 were (mean ± standard error of the mean) 25.5 ± 5.3 and 32.2 ± 6.3, respectively. Corresponding closure in groups 3, 4, and 5 was 55.7 ± 5.0, 57.3 ± 5.0, and 55.6 ± 4.8, respectively (p < 0.05 vs. groups 1 and 2). Groups 6, 7, and 8 closed 32.0 ± 4.5, 38.2 ± 5.3, and 98.5 ± 0.4%, respectively. Significant association between the number of AG-dosages and wound closure indicates dose-related effects in db/db mice.

Chemical and biological characterization of polysaccharides from wild and cultivated roots of Vernonia kotschyana

ETHNOPHARMACOLOGICAL RELEVANCE

In Malian traditional medicine the roots of Vernonia kotschyana are used for treating gastric ulcer and gastritis. In 2006, 9000kg of roots from Vernonia kotschyana were used to produce Gastrosedal, an ameliorated traditional medicine in Mali. Harvesting from the wild, the main source of raw material, is causing a growing concern of diminishing populations of the plant, and Vernonia kotschyana is now being cultivated in several areas around Mali. In the current study the structures and bioactive properties of isolated polysaccharides from wild and cultivated Vernonia kotschyana were compared.

MATERIALS AND METHODS

Pectin- and inulin-type polysaccharides were isolated from the roots of cultivated and wild Vernonia kotschyana. The isolated polysaccharides were investigated regarding their chemical compositions, and for their abilities to fixate human complement and activate macrophages from a mouse macrophage cell line.

RESULTS

No significant differences in the carbohydrate composition of the fractions isolated from the cultivated versus the wild roots were observed. A previously reported pectic arabinogalactan Vk2a was found in both the cultivated and the wild roots in this study, and exhibited potent complement fixation activity, and a moderate activation of macrophages.

CONCLUSIONS

The present study has shown that the cultivated roots of Vernonia kotschyana contain the same types of bioactive polysaccharides as the wild roots. It is therefore preliminarily feasible for the cultivated roots of Vernonia kotschyana to be used as a herbal medicine to replace the wild roots.

Synthesis of curdlan-graft-poly(ethylene glycol) and formulation of doxorubicin-loaded core–shell nanoparticles

A new core–shell nanoparticle containing the chemotherapeutic drug doxorubicin was formulated via amphiphilic graft copolymer self-assembly using curdlan- graft-poly(ethylene glycol) (curdlan -g-PEG). The graft copolymer was synthesized through the dicyclohexylcarbodiimide ester linkage of carboxylated PEG to the hydroxyl groups of the curdlan backbone. The nanoparticles were 109.9 nm in size and encapsulated doxorubicin in high yield (4%–5% wt/wt). The nanoparticles also controlled the release of doxorubicin over 24 h with a release profile that followed a Fickian diffusion model. The biocompatibility of curdlan- g-PEG was confirmed by hemolysis assay. This is the first nanoparticle formulated using the hydrophobicity of curdlan for concealing the immunomodulatory potential of curdlan within the core.

Pharmacological, structural, and drug delivery properties and applications of 1,3-β-glucans

1,3-β-Glucans are a class of natural polysaccharides with unique pharmacological properties and the ability to form single- and triple-helical structures that can be formed into resilient gels with the application of heat and humidity. The pharmacological capabilities of 1,3-β-glucans include the impartation of tumor inhibition, resistance to infectious disease, and improvements in wound healing. Curdlan is a linear 1,3-β-glucan that has been used extensively to study the nature of these helical structures and gels, and Curdlan sulfates have found ongoing application in the inhibition of HIV infection. 1,3-β-Glucan gels have been used in food science as stabilizers and encapsulating agents, in nanoscience as scaffolds to build nanofibers and nanowires, and in drug delivery to form nanoparticles and create helical micelles encapsulating polynucleotides. 1,3-β-Glucans are beginning to have enormous significance due to their dual nature as structure-forming agents and pharmacological substances, and research is especially focused on the application of these polymers in animal nutrition and drug delivery.

Engineered pullulan-collagen composite dermal hydrogels improve early cutaneous wound healing

New strategies for skin regeneration are needed to address the significant medical burden caused by cutaneous wounds and disease. In this study, pullulan-collagen composite hydrogel matrices were fabricated using a salt-induced phase inversion technique, resulting in a structured yet soft scaffold for skin engineering. Salt crystallization induced interconnected pore formation, and modification of collagen concentration permitted regulation of scaffold pore size. Hydrogel architecture recapitulated the reticular distribution of human dermal matrix while maintaining flexible properties essential for skin applications. In vitro, collagen hydrogel scaffolds retained their open porous architecture and viably sustained human fibroblasts and murine mesenchymal stem cells and endothelial cells. In vivo, hydrogel-treated murine excisional wounds demonstrated improved wound closure, which was associated with increased recruitment of stromal cells and formation of vascularized granulation tissue. In conclusion, salt-induced phase inversion techniques can be used to create modifiable pullulan-collagen composite dermal scaffolds that augment early wound healing. These novel biomatrices can potentially serve as a structured delivery template for cells and biomolecules in regenerative skin applications.

Beta-glucans in the treatment of diabetes and associated cardiovascular risks

Diabetes mellitus is characterized by high blood glucose level with typical manifestations of thirst, polyuria, polydipsia, and weight loss. It is caused by defects in insulin-mediated signal pathways, resulting in decreased glucose transportation from blood into muscle and fat cells. The major risk is vascular injury leading to heart disease, which is accelerated by increased lipid levels and hypertension. Management of diabetes includes: control of blood glucose level and lipids; and reduction of hypertension. Dietary intake of beta-glucans has been shown to reduce all these risk factors to benefit the treatment of diabetes and associated complications. In addition, beta-glucans also promote wound healing and alleviate ischemic heart injury. However, the mechanisms behind the effect of beta-glucans on diabetes and associated complications need to be further studied using pure beta-glucan.

Immunomodulatory effects of beta-glucans on porcine alveolar macrophages and bone marrow haematopoietic cell-derived dendritic cells

The immunopharmacological activities of beta-glucans with a backbone of beta-1,3/beta-1,6-linkages associated with anti-tumor, anti-viral, bacterial and fungal infections have been well documented. Dectin-1, a specific pattern recognition receptor for beta-1,3/beta-1,6-glucans, is expressed mainly on phagocytes, especially macrophages and dendritic cells (DCs). In this study, the encoding nucleotide for the carbohydrate-recognition domain (CRD) of porcine dectin-1 was sequenced for the first time, and the immunomodulatory functions of a synthetic particulate beta-glucan (p-beta-glucan) were examined. Results showed that p-beta-glucan significantly enhanced cell activity and phagocytosis in porcine alveolar macrophages (AMs), immature DCs (imDCs) and mature DCs (mDCs), in a similar way to zymosan. Zymosan enhanced dectin-1/TLR2/TLR4 expression and TNF-alpha/IL-10 production in all of three types of cell, whereas p-beta-glucan increased dectin-1/TLR4 and TNF-alpha/IL-12 production in AMs but inhibited IL-10 in mDCs. These results indicate that the complex collaborating interactions between dectin-1 and TLRs in the recognition of beta-1,3/beta-1,6-glucans with different structural features may direct different cellular responses.

Aminated beta-1,3-D-glucan improves wound healing in diabetic db/db mice

Delayed wound healing in diabetes is caused by neuropathy, vascular changes, and impaired cellular response to the injury. Macrophages are crucial in normal wound healing, and impaired functions of these cells have been shown in diabetes. beta-1,3-D-glucans stimulate macrophage function. This open-label study was performed to see if aminated beta-1,3-D-glucan (AG) stimulates wound healing in diabetes. Four groups (1-4) of diabetic db/db mice and one nondiabetic control group, db/+(5) were studied: group 1 (n=11): topical AG; group 2 (n=10): topical AG and subcutaneous insulin; group 3 (n=14): topical placebo and subcutaneous insulin; group 4 (n=10): diabetic control (placebo); group 5 (n=12): normal control (placebo). At the end of the experiments fasting blood glucose and A1C were (mean +/- SE) as follows: Group 1: 30.5 +/- 1.9 mmol/L and 11.3 +/- 0.6%; group 2: 12.0 +/- 1.7 mmol/L and 8.0 +/- 0.6%; group 3: 15.4 +/- 2.4 mmol/L and 7.4 +/- 0.3%; group 4: 32.6 +/- 2.6 mmol/L and 12.3 +/- 0.6%; group 5: 7.2 +/- 0.4 mmol/L and 3.9 +/- 0.04%, respectively. The closed wound area was the same in group 1 (AG alone) and group 2 (AG plus insulin) after 17 days, 57.3 +/- 4.7 vs. 50.1 +/- 4.9% (p=0.7). The results of these two groups were superior to group 3 (insulin treatment alone, 32.0 +/- 4.3%, p<0.001) and diabetic controls (38.2 +/- 5.1%, p=0.001). The macrophage-stimulant AG improves wound healing in db/db mice.

Photoprotective effects of glucomannan isolated from Candida utilis

Glucomannans belong to yeast and fungal cell wall polysaccharides with known immunostimulatory and radioprotective effects. However, glucomannan protective effects against pathological consequences of skin exposure to short wavelength solar light, ultraviolet (UV) radiation, are unclear. Herein, a highly branched glucomannan (GM) isolated from the cell wall of Candida utilis, a member of the alpha-(1-->6)-D-mannan group, was tested for its photoprotective effects in an in vitro model of UVB-irradiated human keratinocytes and an in vivo model of UV-induced erythema formation in human volunteers. GM suppressed the UVB-induced decrease of keratinocyte viability, which was connected with the suppression of UVB-induced keratinocyte apoptosis. GM reduced UVB-mediated caspase activation together with suppression of DNA fragment release into the cytoplasm. Furthermore, GM suppressed UVB-induced gene expression of pro-inflammatory markers including nuclear factor kappa B, inducible nitric oxide synthase, interleukins 8 and 1, together with suppression of prostaglandin E2 and interleukin 1alpha protein release. In vivo, GM decreased UV-induced skin erythema formation, which was correlated with a decrease of phosholipase A(2) activity within the stratum corneum. It could be concluded that GM isolated from C. utilis possesses significant photoprotective effects on human keratinocytes in vitro as well as in vivo.

Yeast glucan particles activate murine resident macrophages to secrete proinflammatory cytokines via MyD88- and Syk kinase-dependent pathways

The therapeutic benefits of fungal beta-glucans have been demonstrated as immuno-stimulating agents. In this study, we aimed to explore the mechanisms used by yeast beta-glucan-rich particles to activate murine resident macrophages for cytokine secretion. We demonstrated that resident macrophages were effectively activated by whole yeast beta-glucan particles (WGPs), such as with the upregulation of co-stimulatory molecules and the secretion of cytokines. The binding ability of WGPs and the levels of cytokine secretion in resident macrophages were significantly inhibited by soluble yeast beta-glucan but not by blockade of zymosan glucan receptor dectin-1. In addition, WGP-stimulated cytokine secretion was partially dependent on the MyD-88 pathway but was not significantly affected in CR3-deficient (CR3(-/-)) mice. Furthermore, we showed that Syk kinase was recruited upon WGP stimulation and was required for the production of cytokines. Taken together, these observations suggest that beta-glucan recognition is necessary but not sufficient to induce inflammatory response on resident macrophages. In addition, beta-glucan particles may use differential mechanisms for cytokine secretion in resident macrophages that may modulate both innate and adaptive immunity.

"Multi Light and Drugs": a new technique to treat face photoaging. Comparative study with photorejuvenation

Nonablative skin rejuvenation using laser, intense pulsed lights (IPLs), or radiofrequency techniques are becoming increasingly popular. In this paper, a novel protocol that integrates IPL sessions, low intense light and vitamin C, low-weight hyaluronic acid, betaglucan dermal injection versus IPL photorejuvenation as monotherapy is compared. A group of 100 patients, all women, with ages ranging from 35 to 65 years old (median age 56.3) with different degrees of photodamage was considered. A blinded control study was done. The patients were divided not randomly into two groups. These groups are similar for ages, skin types, and degrees of photoaging distribution. A first group of 40 patients had monotherapy consisting of seven sessions of IPL only. A second group of 60 patients had triple therapy consisting of seven sessions of IPL as well as nine sessions of low intense diode light and also biostimulation by drugs. Considering only the improvement in hyperpigmentations and teleangectasias, the monotherapy and the triple therapy show good results with no significant statistical difference between the two groups. Considering the improvement in skin texture and firmness in the group treated only with monotherapy, 30% (12 patients) had positive results, and 70% (28 patients) had poor results. In the group treated with triple therapy, 70% (42 patients) had positive results, and 30% (18 patients) had poor results, with the main differences in skin silicone negative imprints. On the basis of the data presented, the new technique of IPL, low intensity diode light, and multidrugs biostimulation seems to be a safe and effective method for skin rejuvenation and upgrades the effects of IPL in the fibroblasts' stimulation.

Medicinal importance of fungal beta-(1-->3), (1-->6)-glucans

Non-cellulosic beta-glucans are now recognized as potent immunological activators, and some are used clinically in China and Japan. These beta-glucans consist of a backbone of glucose residues linked by beta-(1-->3)-glycosidic bonds, often with attached side-chain glucose residues joined by beta-(1-->6) linkages. The frequency of branching varies. The literature suggests beta-glucans are effective in treating diseases like cancer, a range of microbial infections, hypercholesterolaemia, and diabetes. Their mechanisms of action involve them being recognized as non-self molecules, so the immune system is stimulated by their presence. Several receptors have been identified, which include: dectin-1, located on macrophages, which mediates beta-glucan activation of phagocytosis and production of cytokines, a response co-ordinated by the toll-like receptor-2. Activated complement receptors on natural killer cells, neutrophils, and lymphocytes, may also be associated with tumour cytotoxicity. Two other receptors, scavenger and lactosylceramide, bind beta-glucans and mediate a series of signal pathways leading to immunological activation. Structurally different beta-glucans appear to have different affinities toward these receptors and thus generate markedly different host responses. However, the published data are not always easy to interpret as many of the earlier studies used crude beta-glucan preparations with, for the most part, unknown chemical structures. Careful choice of beta-glucan products is essential if their benefits are to be optimized, and a better understanding of how beta-glucans bind to receptors should enable more efficient use of their biological activities.

Praziquantel and liposomized glucan-treatment modulated liver fibrogenesis and mastocytosis in mice infected with Mesocestoides vogae (M. corti, Cestoda) tetrathyridia

Beta-glucans are immunomodulators able to activate innate immunity and to potentiate acquired immune reactions. We investigated the impact of co-administration of liposomized beta-glucan on the larvicidal effect of the anthelmintic praziquantel (PZQ) in the livers and peritoneal cavities in mice infected with Mesocestoides vogae (M. corti). Also, within 2 weeks following therapy (up to day 29 p.i.) we examined collagen synthesis in the livers of mice by means of biochemical determination of hydroxyproline concentration, total mast cell counts and cell proliferative capacity using immunohistochemical and radiometrical methods. After co-administration of liposomized glucan (LG) and PZQ efficacy (%) was significantly higher than after treatment with either compound alone, particularly in the peritoneal cavity compared to the liver. In comparison with the control, more intense collagenesis was found in the B-liver parts (high intensity of infection) and lowering of collagen content in the A-parts (very weak infection). This effect was strongest after LG treatment and co-administration of PZQ abolished the pro-fibrotic effect of LG. In all groups, mast cell counts were higher in the B-liver parts than in the A-parts and the dynamics of mastocytosis was profoundly modulated following therapy. Whereas the effect of PZQ was only moderate, early and very strong onset was seen after LG treatment. Administration of PZQ suppressed LG induced-elevation of mast cells counts in both liver parts. Using DNA S-phase markers (BrdU and 3H-thymidine) the proliferative capacity was shown to be associated with several kinds of liver cells. Therapy significantly stimulated [3H]-thymidine incorporation (cell proliferation) only in the A-parts over that in control, the most after LG administration. In summary (i) the anthelmintic effect of PZQ could be enhanced after simultaneous administration of the immunomodulator beta-glucan entrapped in a liposomal carrier, (ii) intense mastocytosis seen after treatment with LG seems to have a direct role in the glucan's pro-fibrotic activity and can be abolished after co-administration of PZQ in a time-dependent manner, (iii) the pattern of cell proliferation indicates that in the case of PZQ treatment, the reparative processes of liver parenchyma are enhanced in an inverse correlation with the intensity of infection.

Prolonged reduction of leukocyte membrane-associated Dectin-1 levels following beta-glucan administration

Dectin-1 is the primary pattern recognition receptor for fungal glucans. Dectin-1 mediates the internalization and biological response to glucans. We examined the effect of i.v. or i.p. glucan phosphate (GP) administration on Dectin-1 membrane expression in murine peripheral blood leukocytes, splenocytes, bone marrow, and peritoneal cells from 3 h to 10 days after injection. Circulating leukocytes were also examined for uptake and internalization of glucans from the blood. Fluorescent-labeled GP was taken up from the systemic circulation by circulating peripheral leukocytes, splenocytes, and peritoneal cells. Following internalization, glucan colocalized with Dectin-1 in an intracellular vesicle. A single parenteral injection of GP resulted in a significant reduction (approximately 33-85%) in peripheral leukocyte membrane-associated Dectin-1 positivity that lasted for up to 7 days. The loss of leukocyte membrane-associated Dectin-1 after GP administration was primarily due to decreased levels of Dectin-1 on neutrophil and monocyte membranes with no significant changes in the percentage of neutrophils or monocytes circulating in the blood. Administration of control carbohydrate polymers, i.e., mannan or pullulan, which are not ligands for Dectin-1, did not decrease Dectin-1 leukocyte positivity, indicating that the effect on Dectin-1 is specific to glucans. In fact, mannan administration increased leukocyte Dectin-1 positivity, thus demonstrating a differential effect on leukocyte Dectin-1, compared with GP. We conclude that systemic administration of GP has a specific and prolonged effect on loss of leukocyte membrane Dectin-1 positivity. These data may have important implications for developing dosing regimens for immunomodulatory carbohydrates.