In Vitro Evaluation of Antimicrobial Activity of Minocycline Formulations for Topical Application in Periodontal Therapy

A Study on the Use of Phase Transition Lysozyme-Loaded Minocycline Hydrochloride in the Local Treatment of Chronic Periodontitis

Periodontitis is the most important oral disease causing human tooth loss. Although supragingival and subgingival scaling is the main strategy of periodontitis clinical treatments, drug treatment has an indispensable auxiliary role to some degree. Periodontitis medical treatment is divided into systemically administered treatments and local periodontally administered treatments. Compared with systemic administration, local administration can increase local drug concentrations, reduce dosages, and prolong action times while also improving patient compliance and avoiding possible adverse effects due to systemic administration responses. However, some studies show that minocycline ointment, a clinical local drug commonly used in periodontal pockets, has an unstable release rate; 80% of the drug is usually released within 2-3 days after pocket placement. This release is not conducive to controlling periodontal infection and may hinder the periodontal tissue repair and regeneration. Therefore, choosing a suitable carrier for minocycline hydrochloride is necessary to control its local release in periodontal tissue. Phase transition lysozyme (PTL) has been widely used in many studies and the development of macromolecular carrier material, and we selected PTL as the carrier for minocycline hydrochloride drugs because of its good biocompatibility, good drug-carrying capacity, and stable release. Due to its release characteristics and simple preparation, PTL is a promising carrier material.

The Application of Antimicrobial Photodynamic Therapy (aPDT) in the Treatment of Peri-Implantitis

Background

This literature review evaluates the mechanisms and efficacy of different types of antimicrobial photodynamic therapy (aPDT) for treating peri-implantitis by reviewing existing experimental studies to provide guidance for the clinical application of antibacterial photodynamic therapy (aPDT) in oral implants.

Materials and Methods

From February 2001 to February 2021, we have collected 152 randomized controlled trials of aPDT for peri-implantitis by searching the experimental studies and clinical trials published in PubMed, Embase, Web of Science, and Google Scholar databases via online search. After screening the retrieved literature, we finally selected 10 statistically significant literature for evaluation and review.

Results

Compared with the traditional nonsurgical treatment of peri-implantitis, the aPDT was superior to the traditional mechanical irrigation treatment group in terms of periodontal indexes PD, BOP, PLI, and postoperative effect, and the difference was statistically significant (P < 0.05). Furthermore, the combination of the aPDT and other treatments shows the synergistic antibacterial effect, signifying better clinical effect in many aspects (P < 0.05). In these 10 papers, by comparing the probe depth (PD), bleeding on probing (BOP), synosteosis, and periodontal pathogenic bacteria detection, etc., obtained after treating peri-implantitis by application of the antimicrobial photodynamic therapy, and using the SPSS data analysis software for statistical data processing, we found that the antimicrobial photodynamic therapy combined with other periodontal treatments has a more prominent postoperative effect. Meanwhile, the antibacterial photodynamic therapy with targeted action of photosensitizer has strong specificity to some bacteria, while the synthetic photosensitize for antibacterial photodynamic therapy can show good inactivation effect on broad-spectrum periodontal anaerobes without side effect.

Conclusion

The experimental studies and clinical data of antibacterial photodynamic therapy for treating peri-implantitis show a good postoperative treatment effect. In addition, it did not develop resistance due to the use of antibiotic drugs. Owing to multiple advantages from combining antibacterial photodynamic therapy and other treatments, it is applicable for clinical treatment.

What Are the Potential Benefits of Using Bacteriophages in Periodontal Therapy?

Periodontitis, which may result in tooth loss, constitutes both a serious medical and social problem. This pathology, if not treated, can contribute to the development of, among others, pancreatic cancer, cardiovascular diseases or Alzheimer’s disease. The available treatment methods are expensive but not always fully effective. For this reason, the search for and isolation of bacteriophages specific to bacterial strains causing periodontitis seems to be a great opportunity to target persistent colonization by bacterial pathogens and lower the use of antibiotics consequently limiting further development of antibiotic resistance. Furthermore, antimicrobial resistance (AMR) constitutes a growing challenge in periodontal therapy as resistant pathogens may be isolated from more than 70% of patients with periodontitis. The aim of this review is to present the perspective of phage application in the prevention and/or treatment of periodontitis alongside its complicated multifactorial aetiology and emphasize the challenges connecting composition and application of effective phage preparation.

Classic vs. Novel Antibacterial Approaches for Eradicating Dental Biofilm as Adjunct to Periodontal Debridement: An Evidence-Based Overview

Periodontitis is a multifactorial chronic inflammatory disease that affects tooth-supporting soft/hard tissues of the dentition. The dental plaque biofilm is considered as a primary etiological factor in susceptible patients; however, other factors contribute to progression, such as diabetes and smoking. Current management utilizes mechanical biofilm removal as the gold standard of treatment. Antibacterial agents might be indicated in certain conditions as an adjunct to this mechanical approach. However, in view of the growing concern about bacterial resistance, alternative approaches have been investigated. Currently, a range of antimicrobial agents and protocols have been used in clinical management, but these remain largely non-validated. This review aimed to evaluate the efficacy of adjunctive antibiotic use in periodontal management and to compare them to recently suggested alternatives. Evidence from in vitro, observational and clinical trial studies suggests efficacy in the use of adjunctive antimicrobials in patients with grade C periodontitis of young age or where the associated risk factors are inconsistent with the amount of bone loss present. Meanwhile, alternative approaches such as photodynamic therapy, bacteriophage therapy and probiotics showed limited supportive evidence, and more studies are warranted to validate their efficiency.

Local Oral Delivery Agents with Anti-Biofilm Properties for the Treatment of Periodontitis and Peri-Implantitis. A Narrative Review

Despite many discoveries over the past 20 years regarding the etiopathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies continues to rise. For this reason, it was clear that other strategies were needed to eliminate biofilms. In this review, the literature database was searched for studies on locally delivered synthetic agents that exhibit anti-biofilm properties and their potential use in the treatment of two important oral diseases: periodontitis and peri-implantitis.

Clindamycin as an Alternative Option in Optimizing Periodontal Therapy

Periodontal disease is an oral infectious and inflammatory disease caused by microorganisms that determine the host-mediated destruction of soft and hard periodontal tissues, which ultimately leads to tooth loss. Periodontitis affects a large part of the population, with various degrees of severity. Treatment consists of etiologic therapy: the removal of biofilm through mechanical debridement plus microbial elimination by supplementary measures. Antibiotic administration, either systemically or through local delivery, has been shown to improve clinical outcomes after mechanical periodontal treatment. Clindamycin is a lincosamide with a broad spectrum, being active against aerobic, anaerobic, and β-lactamase-producing bacteria. This antibiotic offers several advantages and some disadvantages and has been used in periodontal treatment both systemically and locally with various degrees of success. Among the properties that recommend it for periodontal treatment is the bacteriostatic effect, the inhibition of bacterial proteins synthesis, the enhancement of neutrophil chemotaxis, phagocytosis and the oxidative burst–oxidative stress storm. Furthermore, it is easily absorbed at the level of oral tissues in a considerable amount. This substantial tissue penetration, especially inside the bone, is synergistic with a stimulating effect on the host immune system. The aim of this review is to explore the applicability of this antibiotic agent and to evaluate its antimicrobial potential and limitations at the level of the oral biofilm associated with periodontal disease.

A Review of Systemic Minocycline Side Effects and Topical Minocycline as a Safer Alternative for Treating Acne and Rosacea

Resistance of Cutibacterium acnes to topical antibiotics historically used to treat acne (topical erythromycin and clindamycin and, more recently, topical azithromycin and clarithromycin) has been steadily increasing and new topical antibiotics are needed. Minocycline is a semisynthetic tetracycline-derived antibiotic currently used systemically to treat a wide range of infections caused by Gram-negative and Gram-positive bacteria. In addition to its antibiotic activity, minocycline possesses anti-inflammatory properties, such as the downregulation of proinflammatory cytokine production, suppression of neutrophil chemotaxis, activation of superoxide dismutase, and inhibition of phagocytosis, among others. These characteristics make minocycline a valuable agent for treatment of dermatological diseases such as acne vulgaris and papulopustular rosacea. However, more frequent or serious adverse effects have been observed upon the systemic administration of minocycline than with other tetracyclines. Examples of serious adverse effects include hypersensitivity syndrome reaction, drug-induced lupus, idiopathic intracranial hypertension, and other autoimmune syndromes that may cause death. Here, we review adverse effects and drug–drug interactions observed with oral administration of minocycline and contrast this with topical minocycline formulations recently approved or under development for effectively treating dermatological disorders with fewer adverse effects and less drug interaction.

Dental Practice during COVID-19 in Nepal: A Descriptive Cross-sectional Study

Introduction:

Currently, coronavirus disease (COVID-19) has become pandemic and spread globally. In Nepal, the number of COVID-19 is increasing day-by-day. This research was done to find out the impact of COVID-19 on dentists, patients, and dental practice in Nepal.

Methods:

This study is a cross-sectional study conducted using an online survey from May 10 to17, 2020. A questionnaire was designed and uploaded in Freeonlinesurveys.com. Following ethical approval, the questionnaire was distributed among 500 dentists, and 406 dentists participated in the study. The survey link was dispersed to the Nepali dentists through social media and e-mail, and the results of the responses were received online. The questionnaire consisted of a total of 34 closed-ended questions containing three parts; demographic details, knowledge of dentists on COVID-19, and the impact of COVID-19 on dentists, patients, and dental treatments.

Results:

It showed that majority of the participants were females 243 (60%) of the age group 25-29 years with the clinic as the workplace. Patients receive dental treatments only from 40 (10%) of the dentist. A high number of dentists: 284 (70%) were severely affected by the financial burden and were not receiving a salary during this lockdown. About 349(86%) of the dentist think they should do regular dental treatments, but only 101 (25%) think the dentist should do only dental emergency treatments for COVID-19 infected cases.

Conclusions:

Dentists, patients, and dental practice are severely affected by the COVID-19. The majority of the dentists have faced financial burdens. The dental treatments should be done with high standards of care and infection control following proper recommendations.

Production and characteristics of a novel chicken egg yolk antibody (IgY) against periodontitis-associated pathogens

Periodontitis is a bacterial biofilm-induced oral disease, mostly caused by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis). Oral administration of chicken egg yolk antibody (IgY) is a promising nutritional strategy to control pathogen infections. The objective of this study was to produce an A. actinomycetemcomitans- and P. gingivalis-specific IgY and evaluate its effects on bacterial agglutination and biofilm formation. Thirty laying hens were immunized with a complex of lysate containing typical molecular weights of membrane proteins of A. actinomycetemcomitans and P. gingivalis. IgY was isolated by polyethylene glycol 6000 and ammonium sulfate and purified by dialysis. The results of enzyme-linked immunosorbent assay showed that the obtained IgY were specific to both A. actinomycetemcomitans and P. gingivalis. In addition, immunoelectron microscopy scanning and crystal violet staining showed that the IgY could bind to cell wall of the pathogens and efficiently accelerate agglutination and inhibit biofilm formation. Furthermore, the activity of the IgY remained stable at different temperature, pH, and storage period. This is the first report that a novel two-in-one IgY was produced to modulate the agglutination and biofilm formation of A. actinomycetemcomitans and P. gingivalis, suggesting the potential of IgY to control periodontitis caused by oral pathogens.

Layered biocompatible pH-responsive antibacterial composite film based on HNT/PLGA/chitosan for controlled release of minocycline as burn wound dressing

In the present study, a promising pH-responsive wound dressing was prepared. Halloysite nanotube (HNT) composites were modified with different concentration of both poly (lactic-co-glycolic acid) (PLGA) and chitosan (CS) through the Layer-by-Layer (LbL) strategy for targeted and controlled drug delivery of minocycline (MC). The resulting composites were characterized by FT-IR, XRD, zeta-potential, TGA, FE-SEM and TEM studies. Studying the biodegradability, water uptake, photostability, and water vapor transmission of resulting composites revealed that the composite film absorbed wound secretions, did not degrade, and penetrated properly to wound during the treatment. The results of protein adsorption showed that the optimized composite (C₄₀P₆₀MNT) was blood-compatible. Studying the release profile of the drug showed pH-responsive behavior that was fitted with Korsmeyer-Peppas kinetic model. In-vitro antibacterial testing showed that the C₄₀P₆₀MNT sample had an acceptable effect on the inhibition of gram-positive and gram-negative bacteria. In wound healing test (in-vivo studies), this MC loaded composite film showed faster healing of the burn wound in rat compare to the control sample. Due to the characteristics of the optimized sample, it can be considered as a promising candidate for pH-responsive drug delivery in the treatment of chronic burn wounds.

Analysis of the Antimicrobial, Cytotoxic, and Antioxidant Activities of Cnidium officinale Extracts

This study analyzed the antimicrobial, cytotoxic, and antioxidant properties of Cnidiumofficinale (CO) extracts to confirm their antimicrobial activity toward oral microorganisms. The control group contained 0 μg/mL of CO, and the experimental groups contained 50, 100, 150, and 200 μg/mL of CO. To confirm the antibacterial activity of CO extracts against microorganisms in the oral cavity, an inhibition zone test, a colony-forming unit (CFU) analysis, an optical density (OD) evaluation, and a SEM (scanning electron microscopy) analysis were performed. A cytotoxicity test was also conducted to determine cell viability, and the contents of flavonoids and polyphenols were measured to analyze the extract components. In the control group, the growth inhibition zone increased, while the CFU and OD values decreased (p < 0.05). The SEM analysis confirmed that the number of microorganisms for both the microbes decreased. The cell viability was more than 80% in both the control and experimental groups, excluding the 200 μg/mL sample. The flavonoid and polyphenol contents in the experimental groups showed higher values than those of the control group. Therefore, the CO extract showed considerable antimicrobial activity toward both Streptococcus mutans and Candida albicans, suggesting that it may be used as a natural antimicrobial agent for dental applications.