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This study examined the controlled release of cetylpyridinium chloride (CPC) from a tissue conditioner (TC) containing CPC-montmorillonite (CPC-Mont), the associated antimicrobial activity, and oral mucosa irritation. The CPC release test was performed daily for 28 days in three test solutions: distilled water, 0.2 M NaCl, and 0.2 M HCl. The antimicrobial activities for 7, 14, 21, and 28 days against Candida albicans, Staphylococcus aureus, and Streptococcus mutans were assessed according to the JIS Z 2801/ISO 22196 standard. An oral mucosa irritation test was conducted using cheek pouches in five male hamsters according to the ISO 10993-10:2010 standard. The amount of CPC released each day and the cumulative amount released over 28 days (6.12 mg) were less than the daily safe maximum of sore throat medicines (8 mg). Additionally, TC with CPC-Mont could sustain antimicrobial activity against adherent bacteria for 14 days and has no oral mucosa irritation potential.

A 14-month-old male Armenian hamster ( Cricetulus migratorius) presented with a spontaneous, subcutaneous, firm mass (4.0 × 2.0 × 1.5 cm) on the ventral neck extending towards the cheek pouch causing multifocal small oral ulcerations. This animal was immunized subcutaneously on the dorsal neck for the development of monoclonal antibodies seven months before presentation. The animal was euthanized and necropsy was performed. Histopathology of the mass showed a well demarcated, multilobulated, unencapsulated, highly cellular, neoplastic mass composed of spindle cells arranged in interlacing streams and bundles, with a moderate amount of fibrovascular stroma. The neoplastic cells exhibited indistinct cell borders and a moderate to large amount of eosinophilic, fibrillar cytoplasm, marked anisocytosis and anisokaryosis, binucleated and multinucleated cells, and high mitotic rate. Based on the histomorphologic features of the mass, and the presence of renal tubular hyaline globules and myeloid hyperplasia in the bone marrow, a diagnosis of histiocytic sarcoma was made. The presumptive diagnosis was confirmed by immunohistochemistry, upon which the neoplastic cells showed strong immunoreactivity for the histiocytic cell markers Iba1 and CD11b. Histiocytic sarcomas have been reported in Syrian ( Mesocricetus auratus) and Siberian dwarf ( Phodopus sungorus) hamsters but, to our knowledge, the current report represents the first case of histiocytic sarcoma described in an Armenian hamster. It is plausible to consider the animal’s experimental immunization history and the development of the histiocytic sarcoma to be related. An association between adjuvanted vaccines and soft-tissue sarcomas has been described in cats and referred to as feline injection-site sarcomas.

Translational animal models for oral mucositis (OM) are necessary to simulate and assess the bioclinical effects and response in humans. These models should simulate high levels of radiation exposure that leads to oxidative stress and inflammatory‐initiated tissue changes. Hamster models have been extensively studied to observe pathological effects of radiation exposure and help in the development of effective treatments. To successfully evaluate the potential for treatment regimens with consistency and relevance, a radiation‐induced OM hamster model was developed using a clinical linear accelerator utilized by cancer patients daily. The dose exposure to the isolated, everted cheek pouch of a hamster, as well as the progression of injury, pro‐inflammatory marker, histological, and elasticity analyses of the buccal pouch were conducted to verify replicability and reproducibility of the injury model. The findings from this model demonstrated its ability to consistently induce injury and resolution over 28 days using an acute dose of 60 Gy. This model was developed to enhance clinical relevance when evaluating potential efficacious treatments and can now be utilized in efficacy studies to better evaluate developed therapeutics in a preclinical model that is easy to translate to clinical studies..

Background/Aim: A three-dimensional (3D) printed tracheostomy tube has potential application for patients who require a specialized tube. The aim of this study was to evaluate the characteristics of various 3D printing materials and determine their use in producing 3D-printed tracheostomy tube. Materials and Methods: Mechanical, chemical, and microbiological in vivo changes in the scaffolds were analyzed using a hamster cheek pouch (HCP) model. Results: The poly methyl methacylate (PMMA)-resin showed superior pre- and post-insertion mechanical properties and a relatively consistent lower biofilm formation compared with other scaffolds. PMMA-resin was successfully 3D-printed with dimensional accuracy without a support system. The use of a 3D-printed PMMA tracheostomy tube in a rabbit trachea showed no definite signs of infection, allergy or foreign body reaction. Conclusion: PMMA-resin can be proposed as an alternative for a 3D-printed tracheostomy tube material. In addition, we suggest HCPs as an in vivo model for evaluating indwelling medical devices.

Cheek pouches have evolved from the oral cavity in rodents and act as temporary food storage repositories. There are two types of opening, internal and external. Details about the complex cutaneous muscles controlling the pouches have still not been fully elucidated. To understand the shared and derived traits of the muscles surrounding the cheek pouch and their innervation, we carried out an evolutionary morphological study using two desert kangaroo rats (Dipodomys deserti) and three plains pocket gophers (Geomys bursarius) from each of the two families equipped with external cheek pouches, and four Syrian hamsters (Mesocricetus auratus) with internal cheek pouches. The most conspicuous derived trait of the muscles between the external and internal cheek pouches, the sphincter sacculi, surrounds almost all of the edge of the outer entrance of the pouch. It is present in both species with external pouches, but not in hamsters, which have internal pouches. Our neurological findings demonstrate that most pouch muscles are innervated by both the facial and the cervical nerves, regardless of the pouch type. In these dually innervated muscles, the ventromedial part of the muscles tends to be innervated dominantly or uniquely by the cervical nerves, which usually enter from the superficial or lateral aspect. As a trait shared with the cervical nerves innervating the propatagial muscles in aerodynamic mammals such as bats and flying squirrels, and panniculus carnosus in most mammals, our neurological evidence suggests that the cervical nerve has the potential to innervate derived cutaneous muscles in the cervicofacial region.

Introduction: Cancer is a serious public health problem in many parts of the world; oral squamous cell carcinoma was the 11th most common malignant neoplasm in human papulation. The hamster cheek pouch carcinogenesis model is a well-known animal system that closely mimics the development of premalignant and malignant lesions in human oral cancer. The expressions of cancerization process in this model using DNA ploidy and S-phase fraction is the point of interest. Aim of the study: This research was carried out to study the analysis of DNA ploidy and S-phase fraction in relation to development of oral squamous cell carcinoma during hamster cheek pouches carcinogenesis process induced by DMBA. Material and methods: A total of 50 young gold Syrian hamsters distributed into groups as follows: 2 normal animals examined for the normal histology of the cheek pouch mucosa and 48 animals divided into; group I, as a control group (n= 12), in which pouches were painted with a heavy mineral oil only; group II, were painted with DMBA mixed in a heavy mineral oil (n=36). The examined animal tissue utilized for flow cytometry analysis to obtain DNA ploidy and S-phase fraction development during carcinogenesis process. Results: The flow cytometric analysis of DNA content demonstrated a significant role in carcinogenesis process in oral squamous cell carcinoma. Moreover, they provided a significant analysis in the proliferation and activity of the cancer cells as measured by the S-phase fraction activity.Conclusions: The combinatorial DNA content analysis involving general ploidy and S-phase fraction have potential for support in the early diagnosis; during the development of oral squamous cell carcinoma.

Boron neutron capture therapy (BNCT) is a targeted therapy, which consists of preferential accumulation of boron carriers in tumor followed by neutron irradiation. Each oral cancer patient has different risks of developing one or more carcinomas and/or oral mucositis induced after treatment. Our group proposed the hamster oral cancer model to study the efficacy of BNCT and associated mucositis. Translational studies are essential to the advancement of novel boron delivery agents and targeted strategies. Herein, we review our work in the hamster model in which we studied BNCT induced mucositis using three different cancerization protocols, mimicking three different clinical scenarios. The BNCT-induced mucositis increases with the aggressiveness of the carcinogenesis protocol employed, suggesting that the study of different oral cancer patient scenarios would help to develop personalized therapies.

Boron neutron capture therapy (BNCT) is a promising cancer binary therapy modality that utilizes the nuclear capture reaction of thermal neutrons by boron-10 resulting in a localized release of high- and low-linear energy transfer (LET) radiation. Electrochemotherapy (ECT) is based on electroporation (EP) that induces opening of pores in cell membranes, allowing the entry of compounds. Because EP is applied locally to a tumor, the compound is incorporated preferentially by tumor cells. Based on the knowledge that the therapeutic success of BNCT depends centrally on the boron content in tumor and normal tissues and that EP has proven to be an excellent facilitator of tumor biodistribution of an anti-tumor agent, the aim of this study was to evaluate if EP can optimize the delivery of boronated compounds. We performed biodistribution studies and qualitative microdistribution analyses of boron employing the boron compound sodium decahydrodecaborate (GB-10) + EP in the hamster cheek pouch oral cancer model. Syrian hamsters with chemically induced exophytic squamous cell carcinomas were used. A typical EP treatment was applied to each tumor, varying the moment of application with respect to the administration of GB-10 (early or late). The results of this study showed a significant increase in the absolute and relative tumor boron concentration and optimization of the qualitative microdistribution of boron by the use of early EP + GB-10 versus GB-10 without EP. This strategy could be a tool to improve the therapeutic efficacy of BNCT/GB-10 in vivo.

Background Newly, chemo‐preventive technique might be a hopeful advancement in developing countries for treating cancers with the aid of toxic less natural based constituents. Malignancy urges to augment effectual chemo‐preventive agents that are look forward to suppress the tumours which may be stimulated by chewing and smoking of tobacco and over alcohol consumption related with the high prevalence of human oral cancer (OC) patients. Methods In the present research, we examined to assess antioxidants, lipid peroxidation (LPO) and detoxification enzymes levels of anticancer activity of mangiferin on 0.5% 7.12‐dimethylbenz[a]anthracene (DMBA) provoked hamster cheek pouch carcinoma (HCPC). OC on hamster buccal pouch (HBP) was incited by DMBA treatment for thrice per week for over 14 weeks. Results 100% well defined OC establishment with body weight (bw), tumour burden (TB), antioxidant, LPO and liver marker enzymes and also histological changes were observed on DMBA‐challenged buccal pouch carcinoma (BPC) in hamsters. Orally treated mangiferin at an effective dosage of 50 mg/kg bw, to DMBA painted hamsters were significantly averted the body weight, succession of tumour, the biochemical as well as histopathological changes. Conclusion Findings of this work clearly suggest that the anti‐carcinoma effect of mangiferin possesses the modulator effects on potent antioxidant, anti‐LPO and detoxification agents to expel the metabolites of malignant cells, on DMBA‐provoked BPC in hamsters., Orally treated mangiferin at an effective dosage of 50 mg/kg bw, to DMBA painted hamsters were significantly averted the body weight, succession of tumor, the biochemical as well as histopathological changes. Anti‐carcinoma effect of mangiferin possess the modulator effects on potent antioxidant, anti‐LPO and detoxification agents to expel the metabolites of malignant cells, on DMBA‐provoked BPC in hamsters.

Hamsters are one of the commonly used animal species in research related to virology and infectious agents. Hamsters are similar to human beings in many metabolic and physiological processes. Though the use of hamsters in research has declined in the last few decades, the genetically engineered Syrian hamster (GESH) model is seeing increased popularity due to advancements in gene-editing technologies like CRISPR/Cas9. The presence of immunologically privileged large highly distensible non-glandular cheek pouches makes hamsters a preferred model for oral carcinogenesis, microvascular investigations of inflammation, ischemia-reperfusion investigations, tumor development, and vascular smooth muscle function. Due to the unique immune system of hamsters, skin allografts are not rejected to the degree as compared to other models and have a higher susceptibility to certain infections. It is already known that for, cell culture experiments, Chinese hamster ovary (CHO) cells are extensively used. This chapter will briefly discuss general anatomy, physiology, husbandry, and reproduction, followed by references to reported research uses.