Clinical applications of antimicrobial host proteins lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy and safety

Efficacy of natural enzymes mouthwash: a randomised controlled trial

OBJECTIVES

Natural enzymes mouthwash has been proposed as salivary substitutes to treat xerostomia. This study aims to evaluate the efficacy of the mouthwash to treat xerostomia.

MATERIALS AND METHODS

A double-blind, parallel group randomised control clinical trial involving N = 49 adult participants with xerostomia was carried out. Intervention group received natural enzymes moisturising mouthwash (with active ingredients lactoferrin, lysozyme, lactoperoxidase and glucose oxidase); while control group received benzydamine mouthwash. Mouthwashes were repacked, labelled with specific code, and were given to participants by third-party. Subjects were instructed to rinse with the mouthwash 4 times per day at a specific period, for 2 weeks. Symptoms of xerostomia were assessed using Xerostomia Inventory at day 0 and 14; together with the assessment of Clinical Oral Dryness Score (CODS), and measurement of resting and stimulated salivary flow rate.

RESULTS

48 participants completed the clinical follow-up, and n = 1 had lost of follow-up. From the 48 participants, n = 23 received natural enzymes mouthwash, while n = 25 received benzydamine mouthwash. Intervention group achieved reduction in symptoms of xerostomia from baseline. Intervention group also showed significantly better improvements in the cognitive perception of dry mouth and oromotor function such as chewing, swallowing and speech of the participants; and reduction in waking up at night to drink water (p < 0.05). The CODS and resting salivary flow rate were also significantly improved in intervention group (p < 0.05).

CONCLUSION

Use of natural enzymes mouthwash improved signs and symptoms of xerostomia.

CLINICAL RELEVANCE

Natural enzymes mouthwash is potentially effective to treat xerostomia, well-tolerated and safe to be used by xerostomia patients.

CLINICAL TRIAL REGISTRATION NUMBER

This study was retrospectively registered in ClinicalTrials.gov ID NCT05640362 on 7 December 2022.

Comparison between hangeshashinto and dexamethasone for IL-1α and β-defensin 1 production by human oral keratinocytes

OBJECTIVE

Human β-defensin 1 (hBD-1) is a antimicrobial peptide that is constantly secreted by oral tissues. Hangeshashinto (HST), a traditional Japanese medicine, has been reported to be effective against stomatitis. This study aimed to clarify the profile of HST by comparing the system of production of interleukin-1α (IL-1α) and hBD-1 in human oral mucosal epithelial cells with dexamethasone (DEX), a steroid used for the treatment of stomatitis.

METHODS

Human oral keratinocytes (HOK) were treated with HST, DEX, or HST components (baicalein, baicalin, berberine, and glycyrrhizin) for 24 h, and subsequently cultured for 24 h with or without Pam3CSK4 or lipopolysaccharide (LPS). The cell supernatants, total RNA, and intracellular proteins were collected, and changes in IL-1α and hBD-1 protein production and gene expression were evaluated using ELISA and RT-PCR. The phosphorylation of NF-kB and the cell proliferative ability of HOK were evaluated by western blotting and XTT assay, respectively.

RESULTS

DEX (0.01-10 μM) significantly suppressed IL-1α and hBD-1 production induced by either Pam3CSK4 or LPS, and also decreased cell growth. In contrast, HST inhibited Pam3CSK4- and LPS-induced IL-1α production at a concentration range of 12.5-100 μg/mL without affecting the cell proliferative capacity and hBD-1 production of HOK. Baicalein and baicalin, which are flavonoid ingredients of HST, showed anti-IL-1α production.

CONCLUSION

HST may be useful as a therapeutic agent for stomatitis and other inflammatory diseases of the oral cavity.

Effects of Zinc Compounds on the Enzymatic Activities of Lysozyme and Peroxidase and Their Antifungal Activities

This study aimed to investigate the effects of zinc compounds on the enzymatic activities of lysozyme, peroxidase, and the glucose oxidase-mediated peroxidase (GO-PO) system and their antifungal activities. Four different zinc compounds (zinc chloride, gluconate, lactate, and sulfate) were incubated with hen egg-white lysozyme (HEWL), bovine lactoperoxidase (bLPO), the GO-PO system, and human unstimulated whole saliva in solution and on a hydroxyapatite surface. Enzymatic activities of lysozyme, peroxidase, and the GO-PO system were measured through the hydrolysis of Micrococcus lysodeikticus, oxidation of fluorogenic 2',7'-dichlorofluorescin, and glucose assay, respectively. Interactions between zinc and enzymes were analyzed by surface plasmon resonance (SPR). The minimum inhibitory concentration (MIC) and candidacidal activities of zinc compounds were examined against three Candida albicans strains. Zinc gluconate and sulfate significantly increased the enzymatic activities of salivary lysozyme in the solution assay and of HEWL and salivary lysozyme on the hydroxyapatite surface. However, all examined zinc compounds significantly decreased the enzymatic activities of bLPO and salivary peroxidase in solution and on the surface. SPR analyses revealed binding of zinc to lysozyme and peroxidase, with affinity differing according to the zinc compounds. The MIC of zinc compounds against C. albicans was 1.0-2.4 mM. Candidacidal activities were 17.7-38.8% and 23.7-47.0% at 1.0 and 10 mM concentrations, respectively. In conclusion, zinc compounds enhanced lysozyme activity but inhibited peroxidase activity. Zinc compounds exhibited concentration-dependent candidacidal activity against C. albicans. Zinc compounds are potential therapeutic agents for oral health, especially for geriatric patients.

Assessment of the Salivary Concentrations of Selected Immunological Components in Adult Patients in the Late Period after Allogeneic Hematopoietic Stem Cell Transplantation-A Translational Study

(1) The aim of the study was to analyze the salivary concentrations of lysozyme, lactoferrin, and sIgA antibodies in adult patients in the late period after allogeneic stem cell transplantation (alloHSCT). The relationship between these concentrations and the salivary secretion rate and the time elapsed after alloHSCT was investigated. The relationship between the concentrations of lysozyme, lactoferrin, and sIgA and the titer of the cariogenic bacteria S. mutans and L. acidophilus was assessed. (2) The study included 54 individuals, aged 19 to 67 (SD = 40.06 ± 11.82; Me = 39.5), who were 3 to 96 months after alloHSCT. The concentrations of lysozyme, lactoferrin, and sIgA were assessed in mixed whole resting saliva (WRS) and mixed whole stimulated saliva (WSS). (3) The majority of patients had very low or low concentrations of the studied salivary components (WRS-lysozyme: 52, lactoferrin: 36, sIgA: 49 patients; WSS-lysozyme: 51, lactoferrin: 25, sIgA: 51 patients). The levels of lactoferrin in both WRS and WSS were statistically significantly higher in the alloHSCT group than in the control group (CG) (alloHSCT patients-WRS: M = 40.18 μg/mL; WSS: M = 27.33 μg/mL; CG-WRS: M = 17.58 μg/mL; WSS: 10.69 μg/mL). No statistically significant correlations were observed between lysozyme, lactoferrin, and sIgA concentrations and the time after alloHSCT. In the group of patients after alloHSCT a negative correlation was found between the resting salivary flow rate and the concentration of lactoferrin and sIgA. The stimulated salivary flow rate correlated negatively with lactoferrin and sIgA concentrations. Additionally, the number of S. mutans colonies correlated positively with the concentration of lysozyme and sIgA. (4) The concentrations of non-specific and specific immunological factors in the saliva of patients after alloHSCT may differ when compared to healthy adults; however, the abovementioned differences did not change with the time after transplantation.

Effects of Zinc Compounds on Lysozyme, Peroxidase, and α-Amylase from the Perspective of Oral Health: a Scoping Review

Zinc has been proposed as a topical therapeutic agent for the prevention and treatment of various oral diseases. The purpose of this scoping review was to investigate the effects of zinc on the enzymatic activities of lysozyme, peroxidase, and α-amylase from the perspective of developing oral health care products and therapeutic agents for oral diseases. A comprehensive review of the scientific literature was conducted on the direct interactions of zinc with lysozyme, peroxidase, and α-amylase from various sources. Most of the reports on the effects of zinc on the enzymatic activities of lysozyme, peroxidase, and α-amylase involved enzymes derived from bacteria, fungi, animals, and plants. Studies of human salivary enzymes were scarce. Zinc was found to inhibit the enzymatic activities of lysozyme, peroxidase, and α-amylase under diverse experimental conditions. The suggested mechanism was ionic interactions between zinc and enzyme molecules. The possibility that zinc causes structural changes to enzyme molecules has also been suggested. In conclusion, for zinc to be used as an effective topical therapeutic agent for oral health, further studies on the activity of human salivary enzymes are warranted, and additional information regarding the type and concentration of effective zinc compounds is also required.

Exploring the therapeutic potential of recombinant human lysozyme: a review on wound management system with antibacterial

Lysozyme, a natural antibacterial enzyme protein, possesses the ability to dissolve the cell walls of Gram-positive bacteria, demonstrating broad-spectrum antibacterial activity. Despite its significant potential in treating wound infections and promoting wound healing, its widespread clinical application has yet to be realized. Current research is primarily focused on carrier-based delivery systems for lysozyme. In this review, we discuss four delivery systems that can be employed for lysozyme in wound healing treatment, specifically hydrogels, nanofilms, electrospun fibrous membranes, and modified-lysozyme composite systems. These systems not only enhance the stability of lysozyme but also enable its controlled and sustained release at wound sites, potentially overcoming some of the challenges associated with its direct application. Lastly, we delve into the perspectives and challenges related to the use of these delivery systems, hoping to spur further research and innovation in this promising field.

Antibacterial, antibiofilm and anticaries effect of BioXtra® mouthrinse for head and neck cancer (HNC) patients under a microcosm biofilm model

BACKGROUND AND PURPOSE

Considering the lack of studies investigating salivary substitutes to control post-radiation caries for patients with head and neck cancer (HNC), this study aimed to evaluate the antibacterial, antibiofilm, and anticaries effects of BioXtra® on the microcosm biofilm formed on different enamel types (non-irradiated and irradiated) and from distinct saliva sources (control and HNC patients).

MATERIALS AND METHODS

Non-irradiated and irradiated enamel specimens were treated with BioXtra®, phosphate-buffered-saline (PBS; negative control), or 0.12% chlorhexidine (CHX; positive control) for 1 min. Biofilm was produced from human saliva (healthy participants with normal salivary flow for the control group or irradiated HNC patients with hyposalivation for the HNC group), mixed with McBain saliva, under 0.2% sucrose exposure, daily submitted to the treatments (1 min), for 5 days. Bacterial metabolic activity, biofilm viability, CFU counting, and enamel demineralization were determined.

RESULTS

BioXtra® significantly reduced the bacterial metabolic activity for both enamel types and the inoculum sources, being more effective for the irradiated enamel or for the saliva from the control group. Similarly, BioXtra® significantly reduced the biofilm viability, the CFU for total microorganisms, mutans streptococci, and lactobacilli, and was able to significantly reduce the mineral loss and the lesion depth compared to PBS. CHX was an effective treatment to significantly reduce all parameters, performing better than BioXtra® and reinforcing its reliable efficiency as a positive control.

CONCLUSION

Regardless of the enamel type and the inoculum source, BioXtra® presented antibacterial, antibiofilm, and anticaries effects under this experimental model, which should be confirmed in further clinical studies.

Dental consensus on HSCT - Part II: dental Care during HSCT

During the state of immune vulnerability in hematopoietic stem cell transplantation (HSCT), the patient has an increased risk of developing a vast number of complications, including severe problems in the oral cavity. These situations require professional oral care to act in the diagnosis and treatment of these conditions, as well as to develop prevention protocols to minimize patient's complications. Oral mucositis, opportunistic infections, bleeding, specific microbiota, taste, and salivary alterations are complications that can occur during HSCT and interfere with various aspects, such as pain control, oral intake, nutrition, bacteremia and sepsis, days of hospitalization and morbidity. Several guidelines have been published to address the role of professional oral care during the HSCT, we describe a consensus regarding these recommendations.

Benefits of Natural Antioxidants on Oral Health

In recent years, special attention has been paid to the correlation between oxidation-reduction mechanisms and human health. The free radicals produced via physiological cellular biochemical processes are major contributors to oxidation phenomena. Their instability is the major cause of cellular damage. Free radical reactive oxygen species containing oxygen are the best-known ones. The body neutralises the harmful effects of free radicals via the production of endogenous antioxidants (superoxide dismutase, catalase, glutathione, and melatonin). The field of study of nutraucetics has found antioxidant capacity in substances such as vitamins A, B, C, E, coenzyme Q-10, selenium, flavonoids, lipoic acid, carotenoids, and lycopene contained in some foods. There are several areas of investigation that aim to research the interaction between reactive oxygen species, exogenous antioxidants, and the microbiota to promote increased protection via the peroxidation of macromolecules (proteins, and lipids) by maintaining a dynamic balance among the species that make up the microbiota. In this scoping review, we aim to map the scientific literature on oxidative stress related to the oral microbiota, and the use of natural antioxidants to counteract it, to assess the volume, nature, characteristics, and type of studies available to date, and to suggest the possible gaps that will emerge from the analysis.

Separation Technologies for Whey Protein Fractionation

Whey is a by-product of cheese, casein, and yogurt manufacture. It contains a mixture of proteins that need to be isolated and purified to fully exploit their nutritional and functional characteristics. Protein-enriched fractions and highly purified proteins derived from whey have led to the production of valuable ingredients for many important food and pharmaceutical applications. This article provides a review on the separation principles behind both the commercial and emerging techniques used for whey protein fractionation, as well as the efficacy and limitations of these techniques in isolating and purifying individual whey proteins. The fractionation of whey proteins has mainly been achieved at commercial scale using membrane filtration, resin-based chromatography, and the integration of multiple technologies (e.g., precipitation, membrane filtration, and chromatography). Electromembrane separation and membrane chromatography are two main emerging techniques that have been developed substantially in recent years. Other new techniques such as aqueous two-phase separation and magnetic fishing are also discussed, but only a limited number of studies have reported their application in whey protein fractionation. This review offers useful insights into research directions and technology screening for academic researchers and dairy processors for the production of whey protein fractions with desired nutritional and functional properties.

Impact of different oral treatments on the composition of the supragingival plaque microbiome

Background

Dental plaque consists of a diverse microbial community embedded in a complex structure of exopolysaccharides. Dental biofilms form a natural barrier against pathogens but lead to oral diseases in a dysbiotic state.

Objective

Using a metaproteome approach combined with a standard plaque-regrowth study, this pilot study examined the impact of different concentrations of lactoperoxidase (LPO) on early plaque formation, and active biological processes.

Design

Sixteen orally healthy subjects received four local treatments as a randomized single-blind study based on a cross-over design. Two lozenges containing components of the LPO-system in different concentrations were compared to a placebo and Listerine®. The newly formed dental plaque was analyzed by mass spectrometry (nLC-MS/MS). 

Results

On average 1,916 metaproteins per sample were identified, which could be assigned to 116 genera and 1,316 protein functions. Listerine® reduced the number of metaproteins and their relative abundance, confirming the plaque inhibiting effect. The LPO-lozenges triggered mainly higher metaprotein abundances of early and secondary colonizers as well as bacteria associated with dental health but also periodontitis. Functional information indicated plaque biofilm growth.

Conclusion

In conclusion, the mechanisms on plaque biofilm formation of Listerine® and the LPO-system containing lozenges are different. In contrast to Listerine®, the lozenges led to a higher bacterial diversity.

Effect of experimental and commercial artificial saliva formulations on the activity and viability of microcosm biofilm and on enamel demineralization for irradiated patients with head and neck cancer (HNC)

The effect of different artificial saliva formulations on biofilm activity and viability, and on enamel demineralization for head and neck cancer (HNC) patients was evaluated. Irradiated enamel samples were treated (1 min) with BioXtra® or with experimental formulations containing carboxymethylcellulose plus inorganic constituents alone (AS) or containing 0.1 mg mL^-1 CaneCPI-5 (AS + Cane), 1.0 mg mL^-1 hemoglobin (AS + Hb) or combination of both (AS + Cane + Hb). Phosphate-buffered-saline and chlorhexidine (0.12%) were negative and positive control, respectively. Biofilm was produced from the saliva of five male HNC patients, under 0.2% sucrose exposure for 5 days, and daily treated with the formulations (1 min). No significant effects were observed for the different experimental treatments. BioXtra^® significantly reduced lactobacilli, demonstrating antibacterial potential for this group. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent. Future in vitro studies must be performed using a new approach for the design of the experimental formulations.

Crystal Structure of Human Lysozyme Complexed with N-Acetyl-α-d-glucosamine

Human lysozyme is a natural non-specific immune protein that participates in the immune response of infants against bacterial and viral infections. Lysozyme is a well-known hydrolase that cleaves peptidoglycan in bacterial cell walls. Several crystal structures of human lysozyme have been reported, but little is known regarding how it recognizes sugar molecules. In this study, the crystal structures of human lysozyme in its native and two N-acetyl-α-d-glucosamine (α-D-NAG)-bound forms were determined at 1.3 Å and 1.55/1.60 Å resolution, respectively. Human lysozyme formed a typical c-type lysozyme fold and the α-D-NAG molecule was bound to the middle of subsites C and D. The N-acetyl and glucosamine groups of α-D-NAG were stabilized by hydrophobic interactions (Val117, Ala126, and Trp127), hydrogen bonds (Asn64, Asn78, Ala126, and Val128), and water bridges. Conformational changes of Arg80, Tyr81, Val128, and Arg131 of human lysozyme were observed due to the interactions of α-D-NAG with the active-site cleft. The binding configuration of α-D-NAG in human lysozyme was distinct compared with that of other sugar-bound lysozymes. Findings from this structural analysis provide a better understanding of the sugar recognition of human lysozyme during the immune response to microbial pathogens.

Antioxidant Stress and Anti-Inflammatory Activities of Egg White Proteins and Their Derived Peptides: A Review

Oxidative stress and chronic inflammation are the common pathological bases of chronic diseases such as atherosclerosis, cancer, and cardiovascular diseases, but most of the treatment drugs for chronic diseases have side effects. There is an increasing interest to identify food-derived bioactive compounds that can mitigate the pathological pathways associated with oxidative stress and chronic inflammation. Egg white contain a variety of biologically active proteins, many of which have antioxidant and anti-inflammatory activities and usually show better activity after enzymatic hydrolysis. This review covers the antioxidative stress and anti-inflammatory activities of egg white proteins and their derived peptides and clarifies their mechanism of action in vivo and in vitro. In addition, the link between oxidative stress and inflammation as well as their markers are reviewed. It suggests the potential application of egg white proteins and their derived peptides and puts forward further research prospects.

Antibacterial effects of saliva substitutes containing lysozyme or lactoferrin against Streptococcus mutans

OBJECTIVE

To determine the antibacterial effects of different saliva-substitutes-containing-lysozyme(LYZ) or-lactoferrin(LF) on Streptococcus mutans(S. mutans) in comparison with human saliva.

DESIGN

In vitro wound-healing assay was performed with L929 mouse fibroblast cell line by using various concentrations of LYZ and LF to determine optimum concentrations and to confirm do not show any cytotoxicity of proteins according to cell culture studies. Antibacterial effect was assessed by determining Minimum Inhibitory Concentrations for all groups on S.mutans. Bacterial adhesion of S. mutans for 4 h on hydroxyapatite(HAP) discs after application of different saliva substitutes was evaluated. The formulations were:saliva-substitute(Group SS);saliva-substitute-containing-Lactoferrin(Group SSLF);saliva-substitute-containing-Lysozyme(Group SSLYZ). Human saliva was control group(Group HS).

RESULTS

In vitro wound healing assay results showed that, when added into the cell culture media, LYZ and LF significantly increase 48 -h scratch wound closure compared to the cell culture media(p < 0.0001). At the end of second day, samples treated with both between 2.5-100 μg/mL LF and 5-200 μg/mL LYZ were found to have significant wound healing effect(p < 001). It was observed that saliva-substitutes-containing-LYZ or-LF had antibacterial effects on S.mutans. Bacterial adhesion on HAP discs was observed significantly higher in control group than in study groups. The amount of adhered S. mutans was significantly higher in Group SS than other study groups(p < 0.0001). However, no statistically significant difference was found between the number of bacteria adhered to HAP discs between SSLYZ and SSLF groups(p > 0.05).

CONCLUSIONS

The study of cell viability and wound healing was great significance in the optimum concentrations of LYZ and LF. Among formulations, saliva-substitutes-containing-LYZ or-LF exhibited higher inhibitory effect on S.mutans.

Oral peroxidases: From antimicrobial agents to ecological actors (Review)

Sialoperoxidase and myeloperoxidase are the two main peroxidase enzymes found in the oral cavity. Sialoperoxidase is present in salivary secretions and in the biofilms that line the oral surfaces, while myeloperoxidase is abundant in the dento-gingival sulcus area. In the presence of hydrogen peroxide (H₂O₂), oral peroxidases catalyze the oxidation of the pseudohalide anion thiocyanate (SCN⁻) to hypothiocyanite (OSCN⁻), a strong oxidant that serves an antimicrobial role. Furthermore, oral peroxidases consume bacteria-produced H₂O₂ and could help inactivate toxic carcinogenic and genotoxic substances. Numerous in vitro studies have reported the antibacterial, antimycotic and antiviral role of peroxidases, suggesting possible applications in oral therapy. However, the use of oral hygiene products incorporating peroxidase systems has not yet been shown to be beneficial for the treatment or prevention of oral infections. This paradox reflects our incomplete knowledge of the physiological role of peroxidases in a complex environment, such as the oral region. While hygiene is crucial for restoring oral microbiota to a symbiotic state, there are no data to suggest that the addition of a peroxidase per se can create a dysbiotic state. Recent investigations have associated the presence of peroxidase activity with gram-positive cocci microbial flora, and its insufficiency with dysbiosis has been linked to pathologies, such as caries, periodontitis or infections of the oral mucosa. Therefore, oxidants generated by oral peroxidases appear to be an essential ecological determinant for oral health through the selection of a symbiotic microbiota capable of resisting oxidative stress. The objective of the present review was to update the current knowledge of the physiological aspects and applications of oral peroxidases in clinical practice.

The multifaceted roles of antimicrobial peptides in oral diseases

Antimicrobial peptides are naturally occurring protein molecules with antibacterial, antiviral and/or antifungal activity. Some antimicrobial peptides kill microorganisms through direct binding with negatively charged microbial surfaces. This action disrupts the cytoplasmic membrane and leads to the leakage of the cytoplasm. In addition, they are involved in the innate immune response. Antimicrobial peptides play an important role in oral health, as natural antimicrobial peptides are the first line of host defence in response to microbial infection. The level of natural antimicrobial peptides increases during severe disease conditions and play a role in promoting the healing of oral tissues. However, they are insufficient for eliminating pathogenic micro-organisms. The variability of the oral environment can markedly reduce the effect of natural antimicrobial peptides. Thus, researchers are developing synthetic antimicrobial peptides with promising stability and biocompatibility. Synthetic antimicrobial peptides are a potential alternative to traditional antimicrobial therapy. Pertinent to oral diseases, the deregulation of antimicrobial peptides is involved in the pathogenesis of dental caries, periodontal disease, mucosal disease and oral cancer, where they can kill pathogenic microorganisms, promote tissue healing, serve as biomarkers and inhibit tumor cells. This narrative review provides an overview of the multifaceted roles of antimicrobial peptides in oral diseases.

Hypothiocyanite and Hypothiocyanite/Lactoferrin Mixture Exhibit Virucidal Activity In Vitro against SARS-CoV-2

SARS-CoV-2 replicates efficiently in the upper airways during the prodromal stage, resulting in environmental viral shedding from patients with active COVID-19 as well as from asymptomatic individuals. There is a need to find pharmacological interventions to mitigate the spread of COVID-19. Hypothiocyanite and lactoferrin are molecules of the innate immune system with a large spectrum cidal activity. The Food and Drug Administration and the European Medicines Agency designated the hypothiocyanite and lactoferrin combination as an orphan drug. We report an in vitro study showing that micromolar concentrations of hypothiocyanite exhibit dose- and time-dependent virucidal activity against SARS-CoV-2 and that the latter is slightly enhanced by the simultaneous presence of lactoferrin.

Bioactive proteins in bovine colostrum and effects of heating, drying and irradiation

Bovine colostrum (BC) contains bioactive proteins, such as immunoglobulin G (IgG), lactoferrin (LF) and lactoperoxidase (LP). BC was subjected to low-temperature, long-time pasteurization (LTLT, 63 °C, 30 min) or high-temperature, short-time pasteurization (HTST, 72 °C, 15 s) and spray-drying (SD), with or without γ-irradiation (GI, ∼14 kGy) to remove microbial contamination. Relative to unpasteurized liquid BC, SD plus GI increased protein denaturation by 6 and 11%, respectively, increasing to 19 and 27% after LTLT and to 48% after HTST, with no further effects after GI (all P < 0.05). LTLT, without or with GI, resulted in 15 or 29% denaturation of IgG, compared with non-pasteurized BC, and 34 or 58% for HTST treatment (all P < 0.05, except LTLT without GI). For IgG, only GI, not SD or LTLT, increased denaturation (30-38%, P < 0.05) but HTST increased denaturation to 40%, with further increases after GI (60%, P < 0.05). LTLT and HTST reduced LP levels (56 and 81% respectively) and LTLT reduced LF levels (21%), especially together with GI (47%, P < 0.05). Denaturation of BSA, β-LgA, β-LgB and α-La were similar to IgG. Methionine, a protective amino acid against free oxygen radicals, was oxidised by LTLT + GI (P < 0.05) while LTLT and HTST had no effect. Many anti-inflammatory proteins, including serpin anti-proteinases were highly sensitive to HTST and GI but preserved after LTLT pasteurization. LTLT, followed by SD is an optimal processing technique preserving bioactive proteins when powdered BC is used as a diet supplement for sensitive patients.

Estimation of Proinflammatory Factors in the Saliva of Adult Patients with Cystic Fibrosis and Dental Caries

Introduction: The available literature lacks data regarding the levels of resistin, lysozyme, lactoferrin, α-amylase activity, pH, and saliva buffer capacity, as well as oral health and hygiene in the group of adult patients with cystic fibrosis (CF). The aim of the research was to assess the selected saliva parameters in patients diagnosed with cystic fibrosis. Materials and methods: Examined group was composed of 40 patients diagnosed with CF, while the control group of 40 healthy individuals. Both groups underwent the same scheme of the assessment (DMT index, salivary pH, buffer capacity, analysis of total sialic acid, total protein estimation, lysozyme levels estimation, lactofferin levels measurement, α-amylase activity, estimation of the levels of resistin and TNF-α). Results: In the examined group, there were higher values of decayed teeth as well as values of sialic acid, total protein, lactoferrin, α-amylase, and TNF-α. However, mean lysozyme, and resistin levels, as well as pH and buffer capacity of the saliva, were lower. Conclusions: New diagnostic methods, including the evaluation of selected salivary biochemical parameters, may indicate the existence of factors predisposing to severe tooth decay in the study group. Appropriate preventive treatment to combat dental caries in adult patients with CF will significantly improve their comfort and life expectancy.

Antimicrobials offered from nature: Peroxidase-catalyzed systems and their mimics

The control of antimicrobial resistance requires the development of novel antimicrobial alternatives and naturally occurring peroxidase-catalyzed systems may be of great value in this era of emerging antimicrobial resistance. In the peroxidase system, a peroxidase enzyme catalyzes the oxidation of a halide/pseudohalide, at the expense of hydrogen peroxide, to generate reactive products with broad antimicrobial properties. The appropriate use of peroxidase systems needs a better understanding of the identities and properties of the generated antimicrobial oxidants, specific targets in bacterial cells, their mode of action and the factors favoring or limiting their activity. Here, the ABCs (antibacterial activity, bacterial "backtalk" and cytotoxicity) of these systems and their mimics are discussed. Particular attention is paid to the concomitant use of thiocyanate and iodide dual substrates in peroxidase/peroxidase-free systems with implications on their antimicrobial activity. This review also provides a summary of actual applications of peroxidase systems as bio-preservatives in oral healthcare, milk industry, food/feed specialties and related products, mastitis and wound treatment; lastly, this review points to opportunities for further research and potential applications.

Saliva diagnostics in patients suffering from bisphosphonate-associated osteonecrosis of the jaw: Results of an observational study

OBJECTIVE

One of the severe side effects of bisphosphonate (BP) therapy is bisphosphonate-associated osteonecrosis of the jaw (BONJ). However, there is no information available about its pathogenesis. Hence, the aim of this observational study was to contribute to discerning this pathogenesis by comparing salivary quantity and quality in patients with BONJ and undergoing BP treatment.

MATERIALS AND METHODS

This study included 60 patients divided into three groups. The first group consisted of 20 patients with established BONJ, the second group had 20 patients undergoing BP treatment, and the third group comprised 20 healthy individuals. These groups were analysed for the flow rate of stimulated saliva, buffer capacity, and salivary pH level.

RESULTS

Reduced salivation was observed in a significantly high number of patients with established BONJ (n = 8) and those undergoing BP treatment (n = 9) in comparison with the healthy control group (n = 4; p = 0.039). Though the distribution of the mean value of stimulated saliva flow rates in patients undergoing BP treatment was lower than in the control group, the difference was not significant. Moreover, there were no significant differences in the salivary pH level and buffer capacity in patients undergoing BP treatment as compared with the healthy control group.

CONCLUSIONS

It is possible that the quantity of human saliva is affected by BP treatment. This reduction in saliva production could have a negative effect on mucosal health and is perhaps a cofactor in the pathogenesis of BONJ.

Lysozyme-Induced Transcriptional Regulation of TNF-α Pathway Genes in Cells of the Monocyte Lineage

Lysozyme is one of the most important anti-bacterial effectors in the innate immune system of animals. Besides its direct antibacterial enzymatic activity, lysozyme displays other biological properties, pointing toward a significant anti-inflammatory effect, many aspects of which are still elusive. Here we investigate the perturbation of gene expression profiles induced by lysozyme in a monocyte cell line in vitro considering a perspective as broad as the whole transcriptome profiling. The results of the RNA-seq experiment show that lysozyme induces transcriptional modulation of the TNF-α/IL-1β pathway genes in U937 monocytes. The analysis of transcriptomic profiles with IPA^® identified a simple but robust molecular network of genes, in which the regulation trends are fully consistent with the anti-inflammatory activity of lysozyme. This study provides the first evidence in support of the anti-inflammatory action of lysozyme on the basis of transcriptomic regulation data resulting from the broad perspective of a whole-transcriptome profiling. Such important effects can be achieved with the supplementation of relatively low concentrations of lysozyme, for a short time of exposure. These new insights allow the potential of lysozyme in pharmacological applications to be better exploited.

Cytotoxic effects of a chlorhexidine mouthwash and of an enzymatic mouthwash on human gingival fibroblasts

The aim of this study was to evaluate the cytotoxic effects of an enzymatic mouthwash and of a chlorhexidine mouthwash on human gingival fibroblasts. The metabolic activity of the fibroblasts exposed to each mouthwash was assessed by the MTT assay and the protein content was assessed by the SRB assay. The flow cytometry was used to evaluate the cell cycle and the types of cell death. The oxidative status was evaluated through the DCF and the DHE probes and the intracellular GSH concentration and the mitochondrial membrane potential through JC-1. The cytotoxicity of both mouthwashes was found to be dependent on the exposure time and on the concentration. However, the cytotoxicity of the enzymatic mouthwash was found to be lower than that of the chlorhexidine mouthwash. A trend towards increased oxidative stress was observed for both mouthwashes. After exposing the fibroblasts to the mouthwashes, a G2/M phase block was observed and cell death occurred predominantly by necrosis. The effects of chlorhexidine on fibroblasts were identified at lower concentrations than those used in clinical practice. Therefore, the use of chlorhexidine as an antiseptic in surgical and postoperative situations should be limited. In order to clarify the clinical significance of the enzymatic mouthwash cytotoxicity new clinical studies will be necessary.

Effectiveness of Enzyme Dentifrices on Oral Health in Orthodontic Patients: A Randomized Controlled Trial

Plaque accumulation and white spot lesions are common adverse effects of fixed orthodontic appliance use. This study compared the effects between enzyme-containing and conventional dentifrices on orthodontic patients. This double-blind randomized controlled trial included 42 orthodontic patients (25 women and 17 men: 22.7 ± 4.2 years) from Taipei Medical University Hospital between 2017 and 2018. The patients were randomly divided into three groups and assigned to dentifrice use during the first 3 months of the orthodontic treatment: group 1 used dentifrices containing enzymes including amyloglucosidase and glucose oxidase, group 2 used dentifrices containing 1450 ppm fluoride, and group 3 used natural dentifrices containing no chemical agent. White spot lesion index (WSL), gingival bleeding index (GBI), and visible plaque index (VPI) were recorded and analyzed. WSL, GBI, and VPI values exhibited no significant difference among the three groups. WSL increased significantly in group 3, GBI decreased significantly in all groups, and VPI decreased significantly in groups 1 and 2. No significant difference was observed between the use of enzyme-containing and conventional dentifrices after fixed orthodontic appliance placement.

A randomized, double-blind, placebo-controlled multicenter study for evaluating the effects of fixed-dose combinations of vitamin C, vitamin E, lysozyme, and carbazochrome on gingival inflammation in chronic periodontitis patients

Background

To evaluate gingival inflammation from fixed-dose combinations of vitamin C, vitamin E, lysozyme and carbazochrome (CELC) in the treatment of chronic periodontitis following scaling and root planing.

Methods

One hundred patients were randomly assigned to receive CELC (test) or placebo (control) for the first 4 weeks at a 1:1 ratio, and both groups received CELC for the remaining 4 weeks. Primary outcome was the mean change in the gingival index (GI) after 4 weeks. Secondary outcomes included mean change in GI after 8 weeks and plaque index, probing depth, clinical attachment level, and VAS at 4 weeks and 8 weeks.

Results

Ninety-three patients completed the study. The GI in the test group significantly decreased after 4 weeks (p < 0.001) and 8 weeks (p < 0.001). The mean change from baseline in GI significantly decreased in the test group compared to the control group after 4 weeks (p = 0.015). In the GEE model adjusting for age, gender and visits, the test group showed 2.5 times GI improvement compared to the control group (p = 0.022).

Conclusions

Within the study, CELC showed a significant reduction in gingival inflammation compared with a placebo. Other parameters, however, were similar between groups.

Trial registration

KCT0001366 (Clinical Research Information Service, Republic of Korea) and 29 Jan 2015, retrospectively registered.

The antibacterial efficacy of a foam mouthwash and its ability to remove biofilms

OBJECTIVES/AIMS

To evaluate the antimicrobial activity of a newly developed foam mouthwash containing a modified lactoperoxidase system in vitro.

MATERIALS AND METHODS

Biofilms of five bacterial species were developed on hydrophobic and hydrophilic surfaces whilst salivary-based biofilm was grown on tooth enamel. Each surface was exposed to the foam mouthwash or saline in vitro. Optical density and scanning electron microscopy (SEM) was used to determine retention of the biofilm following 5 or 30 s exposure time.

RESULTS

The foam mouthwash was active against biofilms formed by S. aureus, K. rhizophila, M. thailandicus, E. coli, and C. violaceum and eliminated significant amount of biofilm from each surface; immature 4 h biofilm was less resistant than 24 h biofilm. A 30 s rinse showed best performance, with removal of up to 66% of biofilm from the hydrophilic surface. SEM imaging confirmed oral biofilm removal from the enamel surface after a 5 s rinse with the foam mouthwash.

DISCUSSION

Foam mouthwash demonstrated a significant impact on growing biofilm when compared against saline solution. Growing biofilms were more susceptible to the action of the foam mouthwash, which justifies after-meal use of the mouthwash when traditional dentifrices may not be accessible.

CONCLUSIONS

Foam mouthwash can be a convenient on-the-go format of oral care products that can be used after meals or when needed to reduce the risk of biofilm-associated oral conditions.

Specific and robust ion chromatographic determination of hypothiocyanite in saliva samples

The enzymatic system in saliva, consisting of salivary peroxidase (SPO), hydrogen peroxide (H₂O₂), and thiocyanate (SCN^-), produces hypothiocyanite (OSCN^-) as a high effective antibacterial compound. OSCN^- is of great importance for the natural non-specific antibacterial resistance in the oral cavity. However, no analytical method currently exists to selectively quantify OSCN^- in saliva samples. A robust and specific analytical method for the determination of OSCN^- was developed based on ion chromatography with combined UV and electrochemical detection. Calibration was achieved by calculating a derived calibration factor based on the known ratio of molar extinction coefficients of SCN^- and OSCN^-. Thus, the specific quantification of OSCN^- in saliva samples is possible, as demonstrated here. The median value of 200 saliva samples was determined to be 0.56 mg L^-1 (median), with a maximum of 3.9 mg L^-1; the minimum value was below the detection limit (< 0.09 mg L^-1). The recovery rate in individual saliva samples was 95 ± 8%.

Tannins and Tannin-Related Derivatives Enhance the (Pseudo-)Halogenating Activity of Lactoperoxidase

Several hydrolyzable tannins, proanthocyanidins, tannin derivatives, and a tannin-rich plant extract of tormentil rhizome were tested for their potential to regenerate the (pseudo-)halogenating activity, i.e., the oxidation of SCN^- to hypothiocyanite ^-OSCN, of lactoperoxidase (LPO) after hydrogen peroxide-mediated enzyme inactivation. Measurements were performed using 5-thio-2-nitrobenzoic acid in the presence of tannins and related substances in order to determine kinetic parameters and to trace the LPO-mediated ^-OSCN formation. The results were combined with docking studies and molecular orbital analysis. The ^-OSCN-regenerating effect of tannin derivatives relates well with their binding properties toward LPO as well as their occupied molecular orbitals. Especially simple compounds like ellagic acid or methyl gallate and the complex plant extract were found as potent enzyme-regenerating compounds. As the (pseudo-)halogenating activity of LPO contributes to the maintenance of oral bacterial homeostasis, the results provide new insights into the antibacterial mode of action of tannins and related compounds. Furthermore, chemical properties of the tested compounds that are important for efficient enzyme-substrate interaction and regeneration of the ^-OSCN formation by LPO were identified.

Fluorinated ionic liquids for protein drug delivery systems: Investigating their impact on the structure and function of lysozyme

Since the approval of recombinant human insulin by FDA in 1982, more than 200 proteins are currently available for pharmaceutical use to treat a wide range of diseases. However, innovation is still required to develop effective approaches for drug delivery. Our aim is to investigate the potential use of fluorinated ionic liquids (FILs) as drug delivery systems (DDS) for therapeutic proteins. Some initial parameters need to be assessed before further studies can proceed. This work evaluates the impact of FILs on the stability, function, structure and aggregation state of lysozyme. Different techniques were used for this purpose, which included differential scanning fluorimetry (DSF), spectrophotometric assays, circular dichroism (CD), dynamic light scattering (DLS), and scanning and transmission electron microscopy (SEM/TEM). Ionic liquids composed of cholinium-, imidazolium- or pyridinium- derivatives were combined with different anions and analysed at different concentrations in aqueous solutions (below and above the critical aggregation concentration, CAC). The results herein presented show that the addition of ionic liquids had no significant effect on the stability and hydrolytic activity of lysozyme. Moreover, a distinct behaviour was observed in DLS experiments for non-surfactant and surfactant ionic liquids, with the latter encapsulating the protein at concentrations above the CAC. These results encourage us to further study ionic liquids as promising tools for DDS of protein drugs.

A review of the recent advances in antimicrobial coatings for urinary catheters

More than 75% of hospital-acquired or nosocomial urinary tract infections are initiated by urinary catheters, which are used during the treatment of 15-25% of hospitalized patients. Among other purposes, urinary catheters are primarily used for draining urine after surgeries and for urinary incontinence. During catheter-associated urinary tract infections, bacteria travel up to the bladder and cause infection. A major cause of catheter-associated urinary tract infection is attributed to the use of non-ideal materials in the fabrication of urinary catheters. Such materials allow for the colonization of microorganisms, leading to bacteriuria and infection, depending on the severity of symptoms. The ideal urinary catheter is made out of materials that are biocompatible, antimicrobial, and antifouling. Although an abundance of research has been conducted over the last forty-five years on the subject, the ideal biomaterial, especially for long-term catheterization of more than a month, has yet to be developed. The aim of this review is to highlight the recent advances (over the past 10years) in developing antimicrobial materials for urinary catheters and to outline future requirements and prospects that guide catheter materials selection and design.

STATEMENT OF SIGNIFICANCE

This review article intends to provide an expansive insight into the various antimicrobial agents currently being researched for urinary catheter coatings. According to CDC, approximately 75% of urinary tract infections are caused by urinary catheters and 15-25% of hospitalized patients undergo catheterization. In addition to these alarming statistics, the increasing cost and health related complications associated with catheter associated UTIs make the research for antimicrobial urinary catheter coatings even more pertinent. This review provides a comprehensive summary of the history, the latest progress in development of the coatings and a brief conjecture on what the future entails for each of the antimicrobial agents discussed.

Dose‑dependent effect of lysozyme upon Candida albicans biofilm

The present study investigated the in vitro effect of lysozyme (0-1,000 µg/ml) on Candida albicans (C. albicans) biofilm development. Investigations were conducted on C. albicans ATCC 10231 and on 10 clinical isolates from dentures. Strains were cultured aerobically at 37˚C in Sabouraud broth. Yeast growth was evaluated by turbidimetry. Biofilm biomass was quantified on a polystyrene support by crystal violet staining and on acrylic surfaces by counts of colony forming units. Lysozyme affected biofilm formation to a greater extent than it affected growth. For the ATCC 10231 reference strain, lysozyme acted as a biofilm promotor on polystyrene at the highest concentration tested (1,000 µg/ml, non‑physiological). When the reference strain was investigated on acrylic resin support, lysozyme acted as a significant biofilm promotor on rough resin, but less on smooth resin. The attached biomass in the presence of physiological concentrations of lysozyme (10‑30 µg/ml) was significantly decreased compared with the hypothetical value of 100% using a one‑sample t‑test, but a comparison between the different lysozyme conditions using analysis of variance and post hoc tests did not reveal significant differences. In 10 wild strains, different patterns of biofilm formation on polystyrene were observed in the presence of lysozyme. Some strains, characterized by large amounts of biofilm formation in the presence of 1,000 µg/ml lysozyme, were poor biofilm producers at low concentrations of lysozyme. In contrast, some strains that were poor biofilm producers with a high lysozyme concentration were more inhibited by low concentrations of lysozyme. The present study emphasizes the need to develop strategies for biofilm control based on in vitro experiments, and to implement these in clinical trials prior to approval of hygiene products enriched with exocrine proteins, such as lysozyme. Further studies will extend these investigations to other Candida species, and to fungi and bacteria present in oral biofilms.

Enzymes in therapy of biofilm-related oral diseases

Biofilm-related infections of the oral cavity, including dental caries and periodontitis, represent the most prevalent health problems. For years, the treatment thereof was largely based on antibacterial chemical agents. Recently, however, there has been growing interest in the application of more preventive and minimally invasive biotechnological methods. This review focuses on the potential applications of enzymes in the treatment and prevention of oral diseases. Dental plaque is a microbial community that develops on the tooth surface, embedded in a matrix of extracellular polymeric substances of bacterial and host origin. Both cariogenic microorganisms and the key components of oral biofilm matrix may be the targets of the enzymes. Oxidative salivary enzymes inhibit or limit the growth of oral pathogens, thereby supporting the natural host defense system; polysaccharide hydrolases (mutanases and dextranases) degrade important carbohydrate components of the biofilm matrix, whereas proteases disrupt bacterial adhesion to oral surfaces or affect cell-cell interactions. The efficiency of the enzymes in in vitro and in vivo studies, advantages and limitations, as well as future perspectives for improving the enzymatic strategy are discussed.

Inhibitory effect for proliferation of oral bacteria in dogs by tooth brushing and application of toothpaste

To investigate inhibitory effect for oral bacterial proliferation, we divided 12 dogs into 3 groups; scaling alone (C; control group), brushing (B) and application of toothpaste (P). Before scaling (Pre) and at 0 to 8 weeks after scaling (0-8 w), we collected oral bacteria from the dental surface every week and counted them using a bacterial counter. The results demonstrated a significant reduction in the number of oral bacteria for group B relative to Pre and group C, as well as for group P relative to group C at 5-7 w. Consequently, brushing may inhibit an increase in the number of oral bacteria, and toothpaste may be effective at a certain level, although not more than that of brushing.

Antimicrobial activity and synergism of lactoferrin and lysozyme against cariogenic microorganisms

The present study evaluated the antimicrobial in vitro effects of the salivary proteins lactoferrin and lysozyme on microorganisms involved in the carious process, obtaining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Streptococcus mutans (ATCC 25175) and Lactobacillus casei (ATCC 7469) were submitted to broth macrodilution of lysozyme at 80 mg/mL and lactoferrin at 200 mg/mL. The tubes were read in a spectrophotometer after they had been incubated at 37 °C for 18 h, in a carbon dioxide chamber, in order to read the MIC. A new subculture was carried on agar plates to obtain the MBC. The agar diffusion method was also tested, using BHI agar with 100 µL of the standardized microbial inocula. Filter-paper disks soaked in 10 µL of the solutions lactoferrin (200 µg/mL) and lysozyme (80 µg/mL) were placed on the agar surface. Inhibition halos were not observed on the plates, showing the absence of the antimicrobial effects of these proteins in this method. The bactericidal and bacteriostatic effects of lysozyme on L. casei were 50.3 mg/mL and 43.1 mg/mL respectively. The bactericidal and bacteriostatic effects on S. mutans were 68.5 mg/mL and 58.7 mg/mL. Lactoferrin did not induce any inhibitory effects on any microorganism, even in the concentration of 200 mg/mL. There was not a synergic antimicrobial effect of proteins, when they were tested together, even in the concentration of 42.8 mg/mL of lysozyme and 114 mg/mL of lactoferrin (the highest values evaluated). S. mutans and L. casei were only inhibited by lysozyme, not affected by lactoferrin and by the synergic use of both proteins.

Oral hygiene grade and quality of life in children with chemotherapy-related oral mucositis: a randomized study on the impact of a fluoride toothpaste with salivary enzymes, essential oils, proteins and colostrum extract versus a fluoride toothpaste without menthol

AIM

The aim of this study was to assess the impact of the use of a fluoride toothpaste (Bioxtra^® , Biopharm, Milan, Italy) with salivary enzymes, essential oils, proteins and colostrum extract versus a fluoride toothpaste without menthol on the oral hygiene grade and on the quality of life (QoL) of children with oral mucositis (OM) grade 1 or 2 receiving chemotherapy for Acute Lymphoblastic Leukaemia (ALL).

METHODS

Patients between 6 and 14 years with OM were randomly assigned to two groups, group A (Bioxtra^® toothpaste) and group B (fluoride toothpaste without menthol). The patients were instructed to brush their teeth at least twice a day using a soft toothbrush with a small head. Oral hygiene grade was assessed using the simplified oral hygiene index (OHI-s); quality of life was assessed using the short form of the Oral Health Impact Profile (OHIP-14) questionnaires. The patients were evaluated on day 1(diagnosis of OM-T0) and on day 8 (T1). Statistical analysis was performed.

RESULTS

A total of 64 patients were enrolled. A significant difference (P < 0.001) between the mean of the OHI-s in group A (0.9 ± 1.2) and in group B (1.5 ± 1.3) was found; the overall OHIP-14 scores were not associated with the use of one or the other toothpaste (P = 0.33).

CONCLUSIONS

Although the use of Bioxtra^® toothpaste does not affect the QoL of children undergoing chemotherapy, it may be recommended as clinically effective in improving the oral hygiene grade.

Hyphenated Analytical Methods in Determination of Biologically Active Compounds in Hen's Eggs

Hen's egg is a complete material needed for the development of the embryo; it is an important source of nutraceutical compounds, such as protein, fats, vitamins, trace metals, and minerals. Moreover, avian egg contains biologically active compounds that exhibit antibacterial and antimicrobial activities as well as antitumor, antiviral, antioxidant, immunomodulating, and therapeutic properties. Eggs are mostly very good sources of valuable, easily digestible proteins. This review focuses on the biologically active compounds from hen's egg and applications of these compounds in medicine and the pharmaceutical industry. Additionally, it gives an overview of the hyphenated separation techniques, including sample preparation, analysis, and identification, used in the proteomics and lipidomics analysis.

Large-scale production of functional human lysozyme from marker-free transgenic cloned cows

Human lysozyme is an important natural non-specific immune protein that is highly expressed in breast milk and participates in the immune response of infants against bacterial and viral infections. Considering the medicinal value and market demand for human lysozyme, an animal model for large-scale production of recombinant human lysozyme (rhLZ) is needed. In this study, we generated transgenic cloned cows with the marker-free vector pBAC-hLF-hLZ, which was shown to efficiently express rhLZ in cow milk. Seven transgenic cloned cows, identified by polymerase chain reaction, Southern blot, and western blot analyses, produced rhLZ in milk at concentrations of up to 3149.19 ± 24.80 mg/L. The purified rhLZ had a similar molecular weight and enzymatic activity as wild-type human lysozyme possessed the same C-terminal and N-terminal amino acid sequences. The preliminary results from the milk yield and milk compositions from a naturally lactating transgenic cloned cow 0906 were also tested. These results provide a solid foundation for the large-scale production of rhLZ in the future.

Adsorption Analysis of Lactoferrin to Titanium, Stainless Steel, Zirconia, and Polymethyl Methacrylate Using the Quartz Crystal Microbalance Method

It is postulated that biofilm formation in the oral cavity causes some oral diseases. Lactoferrin is an antibacterial protein in saliva and an important defense factor against biofilm development. We analyzed the adsorbed amount of lactoferrin and the dissociation constant (K(d)) of lactoferrin to the surface of different dental materials using an equilibrium analysis technique in a 27 MHz quartz crystal microbalance (QCM) measurement. Four different materials, titanium (Ti), stainless steel (SUS), zirconia (ZrO2) and polymethyl methacrylate (PMMA), were evaluated. These materials were coated onto QCM sensors and the surfaces characterized by atomic force microscopic observation, measurements of surface roughness, contact angles of water, and zeta potential. QCM measurements revealed that Ti and SUS showed a greater amount of lactoferrin adsorption than ZrO2 and PMMA. Surface roughness and zeta potential influenced the lactoferrin adsorption. On the contrary, the K(d) value analysis indicated that the adsorbed lactoferrin bound less tightly to the Ti and SUS surfaces than to the ZrO2 and PMMA surfaces. The hydrophobic interaction between lactoferrin and ZrO2 and PMMA is presumed to participate in better binding of lactoferrin to ZrO2 and PMMA surfaces. It was revealed that lactoferrin adsorption behavior was influenced by the characteristics of the material surface.