Development of tissue conditioner capable of binding with anti-microbial protein lactoferrin

Lactoferrin as a potential therapeutic for the treatment of Candida-associated denture stomatitis

BACKGROUND

The use of prostheses in the oral cavity creates favorable conditions for Candida colonization, which may subsequently lead to Candida-associated denture stomatitis (CADS). Due to its many contributing factors and frequent relapses, CADS is difficult to manage. Given the rise in drug resistance among fungal species, it is critical to develop new therapeutic approaches, reduce the required dosage of medications, and minimize the toxicity and side effects of therapy.

HIGHLIGHT

Salivary lactoferrin, a multifunctional glycoprotein, is thought to be the first line of defense against microbial invasion of mucosal surfaces.

CONCLUSION

Current research emphasizes the capability of lactoferrin and its derivatives to eliminate a broad spectrum of Candida species. It may be an appealing option for use in monotherapy or in combination with common medications for oral stomatitis treatment. This review provides an overview of the current understanding of lactoferrin's anti-fungal effects in oral candidiasis.

Clinical aspects of the use of lactoferrin in dentistry

BACKGROUND

Lactoferrin (Lf) is a natural iron-binding protein involved in coordinating specific and non-specific immune responses in humans. It exhibits broad spectrum antimicrobial properties against bacteria, viruses, and fungi. Owing to its high affinity for ferric (Fe⁺⁺⁺) ions, Lf is responsible for controlling the oxidative stress in the body, and thus protects cells from oxygen injury. In addition, Lf is a natural immunomodulatory molecule that regulates the activity of the immune system.

HIGHLIGHT

Lactoferrin present in saliva plays an important role in maintaining oral hygiene. It exhibits protective function on mucosal surfaces, which constitute a barrier between the host and the external environment. Thus, Lf may be considered as the first line of defense protein that is associated with oral mucosal immunity.

CONCLUSION

Many studies indicate that lactoferrin supplementation is safe and beneficial for human health. The aim of this review is to discuss the effects of Lf on oral microflora, highlighting the potential significance of this protein in dental therapy and prevention of oral diseases.

Therapeutic Role of Nystatin Added to Tissue Conditioners for Treating Denture-Induced Stomatitis: A Systematic Review

Denture-induced stomatitis (DIS) represents a pathological condition caused by ill-fitting dentures trauma, manifested as inflammation of the palatal tissue beneath the denture. The fungal infections are the principal contributory factors to DIS. Although the aetiology of DIS is multifactorial, the Candida albicans fungal infection remains the main cause. The objective of the present systematic review was to evaluate the latest literature on the addition of nystatin into the tissue conditioners (TCs) in the management of DIS. To search the published literature about “the addition of nystatin in TCs for treating DIS”, electronic databases (PubMed (National library of medicine) and Cochrane Library (Wiley)) were searched (from 1975 until December 2020) using different keywords. Various studies described the effectiveness and efficacy of incorporating nystatin into several TCs. The present systematic review reported that the addition of nystatin is beneficial, with slight or no consequences on both the mechanical and physical features of TCs. Adding nystatin to various TCs for treating DIS can be suggested.

Antifungal and Mechanical Properties of Tissue Conditioner Containing Plant-Derived Component: An In Vitro Study

PURPOSE

To evaluate the antifungal activity and mechanical properties of a novel antifungal tissue conditioner containing Juncus powder.

MATERIALS AND METHODS

Juncus powder was mixed with GC tissue conditioner at concentrations of 2.5%, 5.0%, and 10.0% by mass. The cylindrical specimens of Juncus-mixed tissue conditioner (dimensions: 10 mm in diameter and 2 and 6 mm in height for antimicrobial and mechanical tests, respectively) were prepared. The specimens placed on the bottom of the 24-well tissue culture plate were cultured with Candida albicans CAD1 for 2 and 4 days. The proliferation of the C. albicans in the wells was determined by measuring the optical density of fungal culture, and the surface of the specimens were also observed by scanning electron microscopy (SEM). To assess the mechanical properties of the specimens, the fluidity and hardness of Juncus-mixed tissue conditioner were measured using the methods certified according to ISO 10139-1.

RESULTS

Juncus-mixed tissue conditioner significantly exhibited growth inhibitory effect in a Juncus concentration-dependent manner after both 2- and 4- day cultures. SEM observation showed that the amount of C. albicans on Juncus-mixed specimens drastically decreased, and biofilm formation was markedly inhibited. Moreover, both mechanical properties were found to be within the ranges regulated and specified by ISO.

CONCLUSION

These findings demonstrated that the tissue conditioner including Juncus powder has a significant growth inhibitory effect against C. albicans, and it is suggested that the application of Juncus-mixed tissue conditioner may prevent denture stomatitis and oral candidiasis in denture wearers.

Role of antifungal medicaments added to tissue conditioners: A systematic review

PURPOSE

The aim of this review is to investigate the current state of knowledge on the incorporation of antifungal agents into the tissue conditioners for the treatment of denture induced stomatitis.

STUDY SELECTION

Studies reporting the incorporation of antifungal/antimicrobial agents in to tissue conditioners were included in the review. In order to search the studies on the topic "incorporation of antifungal agents in tissue conditioners for the treatment of denture induced stomatitis" ISI web of science, PubMed/MEDLINE, and Google-Scholar databases were searched from 1970 up to and including July 2015 using various keywords such as antifungal agents, tissue conditioners, Candida albicans, denture stomatitis, etc.

RESULTS

Various studies reported the efficacy and effectiveness of adding conventional organic antifungal medicines (nystatin, azole group derivatives and chlorhexidine, antimicrobials/antifungals other than organic (silver zeolite, silver nano-particles, photo-catalysts and metallic oxides) and natural and herbal antimicrobials (tea tree oil, lemongrass essential oil and origanum oil) into various tissue conditioners. The review literature reported that incorporation of antifungal agents into tissue conditioners is effective with minimal or no effects on physical and mechanical properties of tissue conditioners.

CONCLUSIONS

Incorporation of different antifungal medicaments to commercially available tissue conditioners can be recommended for the management of denture induced stomatitis.

Inhibition of initial bacterial adhesion on titanium surfaces by lactoferrin coating

Because dental implant abutments are located at transmucosal sites, their surface should inhibit bacterial accumulation to prevent peri-implantitis. The authors examined the effects of human lactoferrin (LF), an antibacterial protein present in saliva, as an antibacterial coating on the titanium surface and evaluated its effects before and after mucin-containing artificial saliva (AS) incubation. In the control group, titanium disks were soaked in distilled water, whereas in the LF group, titanium disks were soaked in LF solution to coat the disks. In the control-AS and LF-AS groups, half of the control and LF disks were incubated with AS. To confirm LF adsorption, the fluorescence intensity of fluorescein isothiocyanate-labeled LF was measured. The LF and LF-AS groups showed significantly higher intensity than the control and control-AS groups (P < 0.01). There was no significant difference between the LF and LF-AS groups (P > 0.05). The amount of adhered Streptococcus gordonii significantly increased by incubation with AS (P < 0.01) and significantly decreased by adsorption of LF (P < 0.01). There was no interaction between the two factors, LF adsorption and AS incubation (P = 0.561). These results suggest that the adsorbed LF inhibited bacterial adhesion following AS incubation. According to qualitative LIVE/DEAD analysis, viable bacteria appeared to be decreased in the presence of LF and SEM observation indicated that altered morphologies increased in LF and LF-AS groups. These results suggest that the adsorbed LF remained on the titanium surface after incubation with AS, and the remaining LF inhibited bacterial adhesion and exhibited bactericidal effects. Therefore, the adsorption of LF on the abutment material appears to be effective in preventing peri-implantitis.

Prevention and treatment of Candida colonization on denture liners: a systematic review

STATEMENT OF PROBLEM

Denture liners are well known for their poor physical properties that favor the accumulation of plaque and colonization by Candida species, which can irritate the oral tissues and lead to denture stomatitis.

PURPOSE

A systematic review was conducted to determine the feasibility of a prevention protocol for Candida colonization in denture liners and an effective treatment after the fungi has colonized the material.

MATERIAL AND METHODS

Clinical and in vitro investigations that assessed the treatment and/or prevention of Candida colonization and biofilm formation in denture liners were selected according to the PRISMA statement. Seven electronic databases were searched from 1950 to April 2012 with the keywords "denture liner" OR "reline*" OR "tissue conditioner" AND "Candida" OR "denture stomatitis" OR "oral candidiasis" OR "antifungal agents" OR "denture clean*".

RESULTS

The incorporation of nystatin (in general, 500 000 units) into tissue conditioners to prevent the onset of the disease and immersion in sodium hypochlorite for disinfection were the methods most often described in this systematic review, and both methods were able to prevent or inhibit Candida colonization, depending on their concentrations. The 0.5% sodium hypochlorite concentration can disinfect tissue conditioners and denture liners. Microwave irradiation has also been described an alternative method of disinfection. Because of a lack of standardized results (especially with regard to the method used to perform microbial counts), a meta-analysis could not be performed.

CONCLUSIONS

The literature suggests that the use of 0.5% sodium hypochlorite can help disinfect denture liners and tissue conditioners. The incorporation of nystatin in those materials is also able to treat or prevent oral candidiasis. However, as most of the studies were in vitro, there is insufficient reliable evidence to truly provide recommendations regarding the ideal cleaning method or whether the addition of antifungal agents is worthwhile. Well-designed randomized controlled trials are needed to provide answers to these questions.

Discovery and development of a synthetic peptide derived from lactoferrin for clinical use

There is an urgent need to develop new antimicrobial drugs especially for combating the rise of infections caused by multi-resistant pathogens such as MRSA and VRSA. The problem of antibiotic resistant micro-organisms is expected to increase disproportionally and controlling of infections is becoming difficult because of the rapid spread of those micro-organisms. Primary therapy with classical antibiotics is becoming more ineffective. Combinational therapy of antibiotics with antimicrobial peptides (AMP's) has been suggested as an alternative approach to improve treatment outcome. Their unique mechanism of action and safety profile makes AMP's appealing candidates for simultaneous or sequential use in different cases of infections. In this review, for antimicrobial treatment the application of synthetic antimicrobial peptide hLF(1-11), derived from the first 11 amino acids of human lactoferrin is evaluated in both pre-clinical and clinical settings. Present information indicates that this derivate from lactoferrin is well tolerated in pre-clinical tests and clinical trials and thus hLF(1-11) is an interesting candidate for further exploration in various clinical indications of obscure infections, including meningitis. Another approach of using AMP's is their use in prevention of infections e.g. as coating for dental or bone implants or in biosensing applications or useful as infection specific radiopharmaceutical.

Cell-derived vesicles exposing coagulant tissue factor in saliva

On vascular damage, coagulation is initiated by extravascular tissue factor (TF). Intravascular TF, which is present on circulating cell-derived vesicles, is noncoagulant under physiologic conditions but prothrombotic under pathologic conditions. Human saliva triggers coagulation, but the mechanism and physiologic relevance are unknown. Because saliva is known to contain TF, we hypothesized that this TF may also be associated with cell-derived vesicles to facilitate coagulation when saliva directly contacts blood. The saliva-induced shortening of the clotting time of autologous plasma and whole blood from healthy subjects (n = 10) proved TF-dependent. This TF was associated with various types of cell-derived vesicles, including microparticles and exosomes. The physiologic function was shown by adding saliva to human pericardial wound blood collected from patients undergoing cardiac surgery. Addition of saliva shortened the clotting time from 300 ± 96 to 186 ± 24 seconds (P = .03). Our results show that saliva triggers coagulation, thereby reducing blood loss and the risk of pathogens entering the blood. We postulate that our reflex to lick a wound may be a mechanism to enable TF-exposing vesicles, present in saliva, to aid in the coagulation process and thus protect the organism from entering pathogens. This unique compartmentalization may be highly conserved because also animals lick their wounds.