Management of recurrent aphthous ulcers exploiting polymer-based Muco-adhesive sponges: in-vitro and in-vivo evaluation

Introducing a passively targeted formulation of diclofenac potassium for application in endodontics to minimize renal and gastrointestinal side effects

This research aims to formulate, evaluate, and conduct a clinical investigation of mucoadhesive buccal discs of diclofenac potassium (DP) for application in endodontics to minimize side effects, mainly renal and gastrointestinal. The discs were compressed directly utilizing bioadhesive polymers like hydroxypropyl methylcellulose K4M (HPMC K4M), sodium carboxymethyl cellulose (NaCMC), Carbopol 934 (Cp934), methylcellulose (MC) and combinations of these polymers. In-vitro, release studies and ex-vivo and in-vivo determination of bioadhesion time were conducted. The selected formula was sealed on one surface with ethyl cellulose to allow unidirectional drug release. It was evaluated for permeation through the chicken pouch membrane in the absence and presence of permeation enhancers. The formula of choice (F3) containing methyl cellulose was further assessed for the swelling index, bioadhesion strength, hardness, friability, surface pH, in-vivo bioadhesion performance, and storage effect under ambient and accelerated conditions. It showed drug release of 99 % ± 1 in 2 h, permeation flux (Jss) of 3.5 ± 1.6 mg cm-2 h-1, and bioadhesion time of 4 ± 0.5 h without bitterness, irritation, or fragmentation. The introduced 25 mg DP bioadhesive disc formulation F3 was then clinically compared with the marketed 50 mg oral Cataflam® tablets regarding the effect of single-dose pretreatment in endodontic procedures of subjects with symptomatic irreversible pulpitis (SIP) through a randomized clinical trial. No significant difference was detected in all evaluated clinical criteria. This proves clinical efficiency with the advantage of half-dose administration and targeted localized effect leading to minimized renal and gastrointestinal side effects.

Complexation of α-Mangostin with γ-Cyclodextrin and Its Application in Alginate/Chitosan Hydrogel Mucoadhesive Film for Treatment of Recurrent Aphthous Stomatitis

Introduction

α-Mangostin (α-M), one of the xanthon compound isolated from Garcinia mangostana rind, demonstrates the efficacy in the treatment of recurrent aphthous stomatitis (RAS). The lack of solubility of α-mangostin in water limited its pharmacological application.

Purpose

The lack of solubility of α-mangostin in water limited its formulation and pharmacological application. This study was done to enhance the solubility of α-M by complexation with γ-cyclodextrin (γ-CD) and its application in Alginate/Chitosan Hydrogel Mucoadhesive Film (HMF) for RAS treatment.

Methods

This complex was made by dissolved α-M and γ-CD in separated solution. α-M solution gradualy added into γ-CD to formed α-M/γ-CD complex (α-M/γ-CD CX). This complex then evaporated to yield the dry complex powder. The complex was successfully formulated into hydrogel mucoadhesive film (HMF) preparations based on characterization using Scanning Electron Microscope (SEM), Fourier Transform Infra-Red (FTIR), and X-Ray Diffractometry (XRD). The complex was formulated in hydrogel mucoadhesive film, followed by in-vitro drug release and the study of recurrent aphthous stomatitis (RAS) activity in rats.

Results

The α-M/γ-CD CX HMF film has a higher mucoadhesive force and mucoadhesive time than other HMFs resulting in a prolonged retention time in the oral mucosa. The drug release of α-M/γ-CD CX HMF followed the Korsmeyer-Peppas Model with a total amount of drug released 80.34+0.32%. The inclusion complex of α-M/γ-CD CX HMF exhibited increased anti-RAS activity compared to HMF base, α-M HMF, and α-M/γ-CD PM HMF. This was evidenced by a significant decrease in wound area of approximately 79.05±3.30%, an increase in epithelial thickness of about 1.24±0.09 μm, and a decrease in neutrophil score 1.10±0.26. These findings highlight the potential use of α-M/γ-CD CX as an effective RAS agent in HMF.

Conclusion

The complex of α-M/γ-CD CX has improved solubility of α-M, resulting in the transparent and homogenous film. The film containing this complex has the better physical characteristic, increasing the release and RAS activity.

Multifunctional hydrogels for the healing of oral ulcers

Oral ulcers are one of the most common oral diseases in clinical practice. Its etiology is complex and varied. Due to the dynamic nature of the oral environment, the wound surface is painful due to contact and wear, which seriously affects the quality of life of patients. Oral ulcers are often treated with topical drug therapy. Studies have shown that functional hydrogels play a positive role in promoting wound healing, showing unique advantages in wound dressings. In this paper, the causes and healing characteristics of oral ulcers are discussed in depth, and then the common treatment methods for oral ulcers are summarized and compared. Finally, the potential of functional hydrogels in the treatment of oral ulcers is discussed and projected through a review of the literature in recent years.

Synthesis and biological applications of nanocomposite hydrogels based on the methacrylation of hydroxypropyl methylcellulose and lignin loaded with alpha-pinene

Oral conditions, such as recurrent aphthous stomatitis, are chronic inflammatory disorders that significantly affect the life quality. This study aims to develop a novel buccal mucoadhesive based on methacrylate hydroxypropyl methylcellulose (M-HPMC) and methacrylate lignin (M-SLS) encapsulated with nanostructured lipid carriers (NLCs) for controlled release of alpha-pinene (α-pinene). NLCs with particle sizes of 152 ± 3 nm were prepared by using stearic acid and oleic acid as solid and liquid lipids, respectively. Following the successful synthesis of M-HPMC and M-SLS, various concentrations of α-pinene loaded NLCs (0, 18, 38, and 50 wt%) were encapsulated in M-HPMC/M-SLS hydrogel. It was demonstrated that the physiological and mechanical performances of hydrogels were changed, depending on the NLC content. Remarkably, the incorporation of 18 wt% NLC improved the compressive strength (143 ± 14 kPa) and toughness (17 ± 1 kJ/m3) of M-HPMC/M-SLS hydrogel. This nanocomposite hydrogel considerably decreased dissipated energy from 1.64 kJ/m3 to 0.99 kJ/m3, after a five-cycle compression test. The nanocomposite hydrogel exhibited controlled α-pinene release for up to 96 h which could significantly improve the antioxidant activity of M-HPMC/M-SLS matrix. Moreover, the reinforcing M-HPMC/M-SLS hydrogel with α-pinene-loaded NLCs resulted in increased adhesive strength (113.5 ± 7.5 kPa) to bovine buccal mucosa and cytocompatibility in contact with fibroblasts.

Oral Patch/Film for Drug Delivery-Current Status and Future Prospects

In recent years, there has been extensive research into drug delivery systems aimed at enhancing drug utilization while minimizing drug toxicities. Among these systems, oral patches/films have garnered significant attention due to their convenience, noninvasive administration, ability to bypass hepatic first-pass metabolism, thereby enhancing drug bioavailability, and their potential to ensure good compliance, particularly among special patient populations. In this review, from the perspective of the anatomical characteristics of the oral cavity and the advantages and difficulties of oral drug delivery, we illustrate the design ideas, manufacturing techniques, research methodologies, and the essential attributes of an ideal oral patch/film. Furthermore, the applications of oral patches/films in both localized and systemic drug delivery were discussed. Finally, we offer insights into the future prospects of the oral patch/film, aiming to provide valuable reference for the advancement of oral localized drug delivery systems.

Nature-Inspired Wet Drug Delivery Platforms

Nature has created various organisms with unique chemical components and multi-scale structures (e.g., foot proteins, toe pads, suckers, setose gill lamellae) to achieve wet adhesion functions to adapt to their complex living environments. These organisms can provide inspirations for designing wet adhesives with mediated drug release behaviors in target locations of biological surfaces. They exhibit conformal and enhanced wet adhesion, addressing the bottleneck of weaker tissue interface adhesion in the presence of body fluids. Herein, it is focused on the research progress of different wet adhesion and bioinspired fabrications, including adhesive protein-based adhesion and inspired adhesives (e.g., mussel adhesion); capillarity and Stefan adhesion and inspired adhesive surfaces (e.g., tree frog adhesion); suction-based adhesion and inspired suckers (e.g., octopus' adhesion); interlocking and friction-based adhesion and potential inspirations (e.g., mayfly larva and teleost adhesion). Other secreted protein-induced wet adhesion is also reviewed and various suckers for other organisms and their inspirations. Notably, one representative application scenario of these bioinspired wet adhesives is highlighted, where they function as efficient drug delivery platforms on target tissues and/or organs with requirements of both controllable wet adhesion and optimized drug release. Finally, the challenges of these bioinspired wet drug delivery platforms in the future is presented.

Salivary microbiota and metabolic phenotype of patients with recurrent aphthous ulcers

OBJECTIVES

Recurrent aphthous ulcer (RAU) is a prevalent oral mucosal disease, affecting around 20% of the global population. It can greatly impair the quality of life for affected individuals. However, the exact etiology of RAU remains unknown.

SUBJECTS AND METHODS

16S rRNA sequencing (16S rRNA-seq) and non-targeted liquid chromatography-mass spectrometry (LC-MS) were employed to investigate the salivary microbiota and metabolic phenotype between RAU patients (N = 61) and healthy controls (HCs) (N = 105).

RESULTS

Findings from 16S rRNA -seq indicated reduced oral microbial diversity in RAU patients compared to HCs, but increased interactions. Clinical variables did not show any significant association with the overall diversity of oral microbiota in RAU patients. However, significant correlations were observed between specific microorganisms and clinical variables. LC-MS results revealed dysregulation of amino acid, lipid, nucleotide, and caffeine metabolism in RAU patients. Furthermore, correlation analysis of 16S rRNA-seq and LC-MS data revealed a significant association between salivary microbiota and metabolites in RAU patients.

CONCLUSIONS

Our study revealed notable differences in salivary microbiota and metabolic profiles between RAU patients and HCs, indicating a strong link between oral microbiota dysbiosis, metabolic disturbances, and the onset and progression of RAU.

Biomaterials with antifungal strategies to fight oral infections

Oral fungal infections pose a threat to human health and increase the economic burden of oral diseases by prolonging and complicating treatment. A cost-effective strategy is to try to prevent these infections from happening in the first place. With this purpose, biomaterials with antifungal properties are a crucial element to overcome fungal infections in the oral cavity. In this review, we go through different kinds of biomaterials and coatings that can be used to functionalize them. We also review their potential as a therapeutic approach in addition to prophylaxis, by going through traditional and alternative antifungal compounds, e.g., essential oils, that could be incorporated in them, to enhance their efficacy against fungal pathogens. We aim to highlight the potential of these technologies and propose questions that need to be addressed in prospective research. Finally, we intend to concatenate the key aspects and technologies on the use of biomaterials in oral health, to create an easy to find summary of the current state-of-the-art for researchers in the field.

Association of mucoadhesive polymeric matrices and liposomes for local delivery of miconazole: A new approach for the treatment of oral candidiasis

Since the local treatment of oral candidiasis usually requires long-term administration of the antifungal drug, an ideal dosage form should be able to maintain the drug release over an extended period, assuring an adequate concentration at the infection site. In this context, we have considered the possibility of a buccal delivery of miconazole nitrate (MN) by mucoadhesive polymeric matrices. The loading of the antifungal drug in a hydrophilic matrix was made possible by taking advantage of the amphiphilic nature of liposomes (LP). The MN-loaded LP were prepared by a thin film evaporation method followed by extrusion, while solid matrices were obtained by freeze-drying a suspension of the LP in a polymeric solution based on chitosan (CH), sodium hyaluronate (HYA), or hydroxypropyl methylcellulose (HPMC). MN-loaded LP measured 284.7 ± 20.1 nm with homogeneous size distribution, adequate drug encapsulation efficiency (86.0 ± 3.3 %) and positive zeta potential (+47.4 ± 3.3). CH and HYA-based formulations almost completely inhibited C. albicans growth after 24 h, even if the HYA-based one released a higher amount of the drug. The CH-based matrix also provided the best mucoadhesive capacity and therefore represents the most promising candidate for the local treatment of oral candidiasis.

Natural and Synthetic Drugs Approached for the Treatment of Recurrent Aphthous Stomatitis Over the Last Decade

Recurrent aphthous stomatitis (RAS) refers to a sore and frequently recurring inflammation of the oral tissues, distinguished by the presence of small ulcers that cause significant discomfort and cannot be attributed to any underlying disease. Different treatments have been used for RAS. This review aims to provide a comprehensive overview of the treatment options over the past decade for recurrent aphthous stomatitis (RAS), encompassing both natural and synthetic treatments. It will utilize clinical efficacy studies conducted in vivo and in vitro, along with a focus on the pharmaceutical approach through advancements in drug delivery development. We conducted a thorough literature search from 2013 to 2023 in prominent databases such as PubMed, Scopus, and Cochrane, utilizing appropriate keywords of recurrent aphthous stomatitis, and treatment. A total of 53 clinical trials with 3022 patients were included, with 35 using natural materials in their research and a total of 16 articles discussing RAS treatment using synthetic materials. All the clinical trials showed that natural and synthetic medicines seemed to benefit RAS patients by reducing pain score, ulcer size, and number of ulcers and shortening the healing duration.

A double-layer thin oral film for wet oral mucosa adhesion and efficient treatment of oral ulcers

Oral ulceration (OU), a prevalent oral mucosal condition causing significant pain and hindering eating and speaking, adversely impacts the patient's quality of life. Topical medications are preferred for their minimal side effects and convenient administration. However, existing formulations generally present discomfort and insufficient drug retention due to the thick formulations and poor adhesion, which considerably restrict their therapeutic effectiveness. In this study, a thin and lightweight double-layer oral film based on FDA approved excipients with excellent adhesion under wet oral conditions and outstanding biocompatibility is successfully developed by a simple method. It consists of an adhesive layer for anchoring in situ to delivery drugs and a hydrophobic layer to isolate the saliva for unidirectional drug delivery. The double-layer oral film with extremely thin appearance (only 0.11 mm thick) offers excellent adhesion (up to 150 min on an SD rat oral ulceration), which was also matched with its drug release time (87.47% release in 2 h). Animal experiments confirmed that the double-layer oral film carrying dexamethasone sodium phosphate achieved satisfactory efficacy in the SD rat oral ulcer model. Hence, this biologically friendly double-layer thin oral film holds great promise for clinical application in topical drug therapy for oral mucosal conditions.

A polyglutamic acid/tannic acid-based nano drug delivery system: Antibacterial, immunoregulation and sustained therapeutic strategies for oral ulcers

Oral ulcers are a common inflammatory mucosal ulcer, and the moist and dynamic environment in the oral cavity makes topical pharmacological treatment of oral ulcers challenging. Herein, oral ulcer tissue adhesion nanoparticles were prepared by using esterification reaction between polyglutamic acid and tannic acid, and at the same time doxycycline hydrochloride was loaded into the nanoparticles. The obtained slow drug release effect of the drug-loaded nanoparticles reduced the toxicity of the drug, and by penetrating into the fine crevice region of the wound tissue and adhering to it, they could in-situ release the carried drug more effectively and thus have shown significant antibacterial effects. In addition, tannic acid in the system conferred adhesion, antioxidant and immune regulation activities to the nanocarriers. A rat oral ulcer model based on fluorescent labeling was established to investigate the retention of nanoparticles at the ulcer, and the results showed that the retention rate of drug-loaded nanoparticles at the ulcer was 17 times higher than that of pure drug. Due to the antibacterial and immune regulation effects of the drug-loaded nanoparticles, the healing of oral ulcer wounds was greatly accelerated. Such application of doxycycline hydrochloride loaded polyglutamic acid/tannic acid nanoparticles is a novel and effective treatment strategy for oral ulcer.

Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC's clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of -46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

Efficacy and safety of NAHAO® hydrogel in amelioration of chemoradiotherapy-induced oral mucositis: An preliminary clinical study (ChiCTR2200064766)

OBJECTIVE

To evaluate the efficacy of NAHAO® oral mucosal antibacterial care solution (NAHAO® spray) on attenuating oral mucositis (OM) symptoms and related mechanisms investigation.

MATERIAL AND METHODS

Experimental OM models were established by acetic acid and 5-fluorouracil combined with mechanical trauma. We investigated spontaneous pain of conscious OM rats after using NAHAO®. The expression of NF-κB in affected trigeminal ganglion was measured by western blot. In clinical study, 60 patients who developed post-treatment OM of grade 2 or above or persistent mucosal pain with a score equal to or greater than 4 points were selected. All patients were required to receive NAHAO® spray 8 times a day and were examined for OM degrees and oral mucosal pain scores before and after application.

RESULTS

Experimental data from experimental model suggested that clinical efficacy of NAHAO® spray was involved in inflammation inhibition via NF-κB pathway. The results of clinical study showed that NAHAO® spray improved the symptoms of OM, there is statistically significant difference in oral mucosal pain scores after treated with NAHAO, and the dietary restrictions were also improved.

CONCLUSION

NAHAO® spray alleviates pain and improves the diet situation in OM patients, which is partly mediated through the inhibition of NF-κB pathway.

Thiolated chitosan hydrogel-embedded niosomes: A promising crocin delivery system toward the management of aphthous stomatitis

Aphthous stomatitis is a common inflammatory oral disease with challenging management. Crocin is a natural carotenoid that has shown great anti-inflammatory properties. The aim of this study was to develop thiolated chitosan (TCS)-based hydrogels containing niosomes to serve as a mucoadhesive crocin delivery system for aphthous stomatitis. Crocin-loaded niosomes were prepared and the impact of surfactant type, cholesterol content, and lipid to drug ratio on the characteristics of niosomes was evaluated. TCS was synthesized and the success of thiolation was investigated. The optimum niosomal formulation was loaded into the hydrogel and the hybrid system was characterized regarding the morphology, mucoadhesive properties, viscosity, chemical structure, in vitro drug release, and in vivo efficacy. The optimized niosome formulation showed 77% crocin entrapment, a particle diameter of 59 nm, and a zeta potential of -18 mV. The niosome-containing hydrogel exhibited pseudoplastic rheological behavior, mucoadhesive properties, suitable swelling, and sustained release of crocin. In vivo study revealed that the niosome-containing hydrogel improved ulcer healing and decreased the expression of tumor necrosis factor-alpha (TNF-α) and p53 while increasing the expression of vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (α-SMA). Collectively, TCS hydrogel-embedded crocin-loaded niosomes is a promising therapeutic option for aphthous stomatitis. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Crocin (PubChem CID: 5281233) Chitosan (PubChem CID: 71853) Thioglycolic acid (PubChem CID: 1133) 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (PubChem CID: 2723939) 5,5'-dithiobis (2-nitrobenzoic acid) (PubChem CID: 6254) Cholesterol (PubChem CID: 5997).

Formulation and Evaluation of Prednisolone Sodium Metazoate-Loaded Mucoadhesive Quatsomal Gel for Local Treatment of Recurrent Aphthous Ulcers: Optimization, In Vitro, Ex Vivo, and In Vivo Studies

This study aims to formulate a buccal mucoadhesive gel containing prednisolone sodium metazoate-loaded quatsomes for efficient localized therapy of recurrent aphthous ulcers. Quatsomes were prepared using a varied concentration of quaternary ammonium surfactants (QAS) and cholesterol (CHO). A 2³ factorial design was conducted to address the impact of independent variables QAS type (X₁), QAS to CHO molar ratio (X₂), and sonication time (X₃). The dependent variables were particle size (PS; Y₁), polydispersity index (PDI; Y₂), zeta potential (ZP; Y₃), entrapment efficiency percent (EE%; Y₄) and percent of drug released after 6 h (Q6%: Y₅). Then, the selected quatsomes formula was incorporated into different gel bases to prepare an optimized mucoadhesive gel to be evaluated via in vivo study. The PS of the developed quatsomes ranged from 69.47 ± 0.41 to 113.28 ± 0.79 nm, the PDI from 0.207 ± 0.004 to 0.328 ± 0.004, ZP from 45.15 ± 0.19 to 68.1 ± 0.54 mV, EE% from 79.62 ± 1.44 to 98.60% ± 1.22 and Q6% from 58.39 ± 1.75 to 94.42% ± 2.15. The quatsomal mucoadhesive gel showed rapid recovery of ulcers, which was confirmed by the histological study and the evaluation of inflammatory biomarkers. These results assured the capability of the developed quatsomal mucoadhesive gel to be a promising formulation for treating buccal diseases.

Dual-light defined in situ oral mucosal lesion therapy through a mode switchable anti-bacterial and anti-inflammatory mucoadhesive hydrogel

Oral mucosal ulcer is the most prevalent oral mucosal lesion, affecting the quality of life. Due to the moist and highly dynamic oral lining, the existing oral mucoadhesives are unable to serially address the challenges of residency, hemorrhage, bacterial infection and inflammatory reaction. Herein, a dual-light defined oral mucoadhesive (ZPTA-G/HMA) was proposed, with a methacrylate gelatin-methacrylate hyaluronic acid (GelMA-HAMA, G/HMA) double network hydrogel as a matrix, tannic acid (TA) as a high content anchor moiety provider for the moist oral mucosa, and polydopamine modified zinc oxide (ZnO@PDA, ZP) as a photocatalytic antibacterial substance. This platform had good adhesive and hemostatic properties both in vitro and in vivo. Under 520 nm green light (GL) irradiation, ZPTA-G/HMA would anchor to the wet mucosa surface by crosslinking and exert broad-spectrum antibacterial ability (even including Candida albicans) by in situ producing reactive oxygen species (ROS). Moreover, under 808 nm near-infrared (NIR) irradiation, the increased release of TA combined with the photothermal effect of ZP endowed ZPTA-G/HMA with enhanced anti-inflammatory and pro-healing performance. Collectively, ZPTA-G/HMA could be switched by light sources to achieve the dual-mode real-time adjustment of in situ anti-bacterial function and controlled anti-inflammation, combined with ideal mucosal residence, thus promising in developing personalized sequential strategies for varied oral mucosal lesions.

Alginate/Chitosan-Based Hydrogel Film Containing α-Mangostin for Recurrent Aphthous Stomatitis Therapy in Rats

Recurrent aphthous stomatitis (RAS) is a prevalent clinical disorder that causes mouth ulcers. Furthermore, corticosteroid treatment has been widely utilized for RAS therapy; however, it has side effects on the oral mucosa that limit its application. This study aimed to develop a novel RAS therapy with the natural ingredient α-mangostin, delivered by alginate and chitosan polymers-based hydrogel film (α-M Alg/Chi-HF). To prepare α-M Alg/Chi-HF, the solvent evaporation and casting methods were used, then characterized by using SEM, FTIR, and XRD. Based on the characterization studies, the α-M in α-M/EtOH Alg/Chi-HF with ethanol (EtOH) was found to be more homogenous compared to α-M in Alg/Chi-HF with distilled water (H2O) as a casting solvent. The in vitro viability study using NIH3T3 cells showed 100% viability of α-M Alg/Chi-HF (EtOH) and Alg/Chi-HF after 24 h incubation, indicating well tolerability of these hydrogel films. Interestingly, the in vivo studies using male white rats (Rattus norvegicus Berkenhout) proved that α-M/EtOH Alg/Chi-HF with a recovery of 81.47 ± 0.09% in seven days significantly more effective RAS therapy compared to control. These results suggest that α-M/EtOH Alg/Chi-HF has the potential as an alternative for RAS therapy.

HPLC/MSn Profiling and Healing Activity of a Muco-Adhesive Formula of Salvadora persica against Acetic Acid-Induced Oral Ulcer in Rats

Salvadora persica L. (S. persica, Siwak) is an ethnic plant that is widely used for improving oral hygiene. This study aimed to provide a phytochemical profiling of S. persica ethyl acetate fraction (SPEAF) and to evaluate the healing activity of a muco-adhesive formula of the fraction against acetic acid-induced oral ulcers in rats. HPLC-ESI-QTOF-MS-MS analysis of SPEAF resulted in the tentative identification of 56 metabolites containing fatty acids (23%), urea derivatives (10.5%) and sulphur compounds (10%), in addition to several amides, polyphenols and organic acids (6.5%, 5% and 2%, respectively). For the first time, 19 compounds were identified from S. persica. In vitro and in vivo experiments indicated that the extract is non-toxic. SPEAF exhibited superior healing activities compared to both the negative and positive control groups on days 7 and 14 of tongue ulcer induction. This was confirmed by histopathological examinations of haematoxylin and eosin-stained (H&E) and Masson's trichrome-stained tongue sections. Moreover, SPEAF showed potent anti-inflammatory activities, as evidenced by the inhibited expression of interleukin-6 (IL-6) and tumour necrosis alpha (TNF-α). Moreover, SPEAF exhibited potent antioxidant activity, as it prevented malondialdehyde (MDA) accumulation, reduced glutathione (GSH) depletion and superoxide dismutase (SOD) exhaustion. SPEAF significantly enhanced hydroxyproline tongue content and upregulated collagen type I alpha 1 (Col1A1) mRNA expression. SPEAF also improved angiogenesis, as shown by the increased mRNA expression of the angiopoietin-1 (Ang-1). In conclusion, S. persica has a wide range of secondary metabolites and ameliorates acetic acid-induced tongue ulcers in rats. This can be attributed, at least partly, to its anti-inflammatory, antioxidant, procollagen and angiogenic activities. These findings provide support and validity for the use of S. persica as a traditional and conventional treatment for oral disorders.

The Expanded Role of Chitosan in Localized Antimicrobial Therapy

Chitosan is one of the most studied natural origin polymers for biomedical applications. This review focuses on the potential of chitosan in localized antimicrobial therapy to address the challenges of current rising antimicrobial resistance. Due to its mucoadhesiveness, chitosan offers the opportunity to prolong the formulation residence time at mucosal sites; its wound healing properties open possibilities to utilize chitosan as wound dressings with multitargeted activities and more. We provide an unbiased overview of the state-of-the-art chitosan-based delivery systems categorized by the administration site, addressing the site-related challenges and evaluating the representative formulations. Specifically, we offer an in-depth analysis of the current challenges of the chitosan-based novel delivery systems for skin and vaginal infections, including its formulations optimizations and limitations. A brief overview of chitosan's potential in treating ocular, buccal and dental, and nasal infections is included. We close the review with remarks on toxicity issues and remaining challenges and perspectives.

Effect of nano-chitosan and nano-doxycycline gel on healing of induced oral ulcer in rat model: histological and immunohistochemical study

OBJECTIVES

The aim of this study was to investigate the effect of nano-chitosan and nano-doxycycline gel on healing of oral ulcers.

METHODS

In this study, 37 rats were used, four of which acted as normal controls (group 1), while the remaining 33 were distributed into three groups, each with 11 rats. Oral ulcers were chemically induced in the labial mucosa, after which (group 2), ulcer group received no treatment, (group 3) received nano-chitosan gel, and (group 4) received nano-doxycycline gel. They were scarified after 14 days and histologically examined as well as immunostaining for vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA).

RESULTS

The best clinical and histologic healing results were shown in nano-chitosan group, followed by nano-doxycycline group, while the ulcer group showed incomplete healing. This was confirmed by immunostaining as area % of VEGF and number PCNA were the highest in nano-chitosan group followed by nano-doxycycline group, then ulcer group.

CONCLUSION

Both nano-chitosan and nano-doxycycline gels improved the healing of chemically induced oral ulcers; however, nano-chitosan exhibited better healing outcomes.

CLINICAL RELEVANCE

Nano-chitosan and nano-doxycycline gels are both viable and safe alternatives to current ulcer treatments.

Evaluation of Novel Topical Camel Whey Protein Gel for the Treatment of Recurrent Aphthous Stomatitis: Randomized Clinical Study

Aim:

The aim of this article is to evaluate the topical effect of camel whey protein (CWP) on the healing of recurrent aphthous stomatitis (RAS) and the serum levels of interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α.

Materials and Methods:

Forty patients with minor RAS were randomly assigned into control and study groups. The control group applied placebo methylcellulose gel topically over the aphthous ulcer, whereas the study group used CWP dissolved in methylcellulose gel topically over the aphthous ulcer. Healing period, pain scale, and serum inflammatory biomarkers were evaluated before and after gel application. Collected data were analyzed statistically using the paired t-test or independent sample t-test.

Results:

Ulcer healing period, pain scale, and immunological biomarkers were statistically improved in both groups with significant shortening of the ulcer duration and significant regulation of immunological values related to the study group.

Conclusion:

Topical CWP gel is potentially effective in the treatment of RAS.

Nattokinase crude extract enhances oral mucositis healing

Background

Nattokinase (NK) is a promising alternative in the prevention and treatment of cardiovascular diseases due to its potent fibrinolytic activity. In this study, we investigated the effect of crude nattokinase extract on the healing of acetic acid-induced oral mucositis in mice.

Methods

Bacillus subtilis culture media (BSCM) was isolated into the supernatant, named nattokinase crude extract (NCE), and the pellet was named Bacillus subtilis mass (BSM). An oral mucositis model was established in mice by applying 50% glacial acetic acid to the buccal mucosa. According to the treatment conditions, the mice were divided into BSCM, NCE, BSM and phosphate buffered saline (PBS) groups. The weight of the mice, oral mucositis healing score and histopathological examination were used to evaluate the treatment.

Results

Fibrinolytic activities of BSCM, NCE and BSM were approximately 8069, 10,800 and 80 U/ml, respectively. The weight gain of mice in the NCE group was significantly different from the PBS group after three days’ treatment (p < 0.05). The oral mucositis score of NCE group was significantly higher than other groups (p < 0.05). The differences in histopathology scores between the NCE and other groups were statistically significant (p < 0.01).

Conclusions

NCE could possess remarkable potential to reduce pain and promote oral mucositis healing with minimal safety concerns. In this study, we first report that NCE from the supernatant of Bacillus subtilis can promote the healing of oral mucositis, which extends the application scope of NK.