Electron microscopic immunogold localization of salivary mucin MUC5B in human buccal and palatal glands

Scent of relief: Mastic resin scent recovers salivation in chronic dry mouth patients

BACKGROUND

Olfactory stimulation with mastic resin, derived from the Pistacia lentiscus tree, demonstrated a bona fide sialagogic effect in healthy volunteers [1]. Its main volatile compound, α-pinene, also showed this effect. The current study aimed to validate the effect of mastic resin volatiles in chronic dry mouth patients with confirmed decreased saliva secretion.

METHODS

41 chronic dry mouth patients with decreased unstimulated saliva secretion (<0.25 mL/min) were exposed to mastic resin volatiles as part of the diagnostic routine at the Saliva Clinic of Academic Centre for Dentistry Amsterdam. During their visit, dry-mouth questionnaires were conducted and samples of unstimulated whole saliva, chew-stimulated saliva, acid-stimulated saliva and mastic resin stimulated saliva were collected. Saliva flow rate, spinnbarkeit, pH, ion composition, MUC5B and MUC7 levels in all samples were analyzed.

RESULTS

Salivary flow rates increased by all stimuli when compared to the baseline unstimulated saliva (P<0.001). During olfactory mastic resin stimulation, the salivary spinnbarkeit (P<0.001) and sodium concentration (P<0.01) were increased compared to unstimulated saliva. MUC5B and MUC7 levels were increased during olfactory mastic resin stimulation compared to chew-stimulated saliva (P=0.016 and P<0.001, respectively). Spinnbarkeit correlated positively with MUC5B (R=0.399, P=0.002) and MUC7 levels (R=0.375, P=0.004). Results of dry-mouth questionnaires indicated reduced posterior palate dryness shortly after olfactory mastic resin stimulation (P=0.04).

CONCLUSIONS

Olfactory mastic resin stimulation increased mucous saliva secretion and reduced posterior palate dryness in a group of chronic dry mouth patients. These findings, validated in patients, underscore mastic resin scent as a beneficial and non-invasive sialagogic treatment for clinical applications.

Evaluation of oral care using MA-T gel for high-risk patients: a pilot study

BACKGROUND

Oral care with gel is a common method for preventing aspiration in high-risk patients. An oral care gel is used to clean and moisturize the oral cavity. However, the effects of gel care on the oral bacteria remain unclear. In this pilot study, we described a matching transformation system (MA-T) for elderly high-risk patients. MA-T is an on-demand aqueous chlorine dioxide solution that provides excellent safety and has various antimicrobial activities, even in the presence of abundant organic compounds. This study investigated the effects of MA-T gel in patients requiring nursing care.

MATERIALS AND METHODS

Patients who were hospitalized for nursing care were included in this study. No drugs and foods were administered orally. Oral bacteria and intraoral humidity were examined by daily care using MA-T gel. Moreover, oral membranous substances were analyzed and material from the oral cavity was cultured on selective media for identifying opportunistic organisms.

RESULTS

Membranous substances were present in the oral cavities of all patients. The number of bacteria decreased, and oral moisture improved, after treatment with MA-T gel. Moreover, oral humidity was also controlled with the continued use of MA-T gel. MA-T gels should be used not only for professional care but also on a daily basis for better oral care. Furthermore, the results of bacterial cultures showed that MA-T controls the propagation of opportunistic bacterial infections.

CONCLUSION

Membranous substances may be observed in the oral cavity of individuals requiring nursing care for tube feeding. The results of this pilot study suggest that MA-T, a novel disinfectant, can be used for oral care in the elderly to reduce the risk of aspiration-pneumonia.

The Translational Role of MUC8 in Salivary Glands: A Potential Biomarker for Salivary Stone Disease?

Mucin (MUC) 8 has been shown to play an important role in respiratory disease and inflammatory responses. In the present study, we investigated the question of whether MUC8 is also produced and secreted by salivary glands and whether it may also play a role in the oral cavity in the context of inflammatory processes or in the context of salivary stone formation. Tissue samples from parotid and submandibular glands of body donors (n = 6, age range 63–88 years), as well as surgically removed salivary stones from patients (n = 38, age range 48–72 years) with parotid and submandibular stone disease were immunohistochemically analyzed targeting MUC8 and TNFα. The presence of MUC8 in salivary stones was additionally analyzed by dot blot analyses. Moreover, saliva samples from patients (n = 10, age range 51–72 years), who had a salivary stone of the submandibular gland on one side were compared with saliva samples from the other “healthy” side, which did not have a salivary stone, by ELISA. Positive MUC8 was detectable in the inter- and intralobular excretory ducts of both glands (parotid and submandibular). The glandular acini showed no reactivity. TNFα revealed comparable reactivity to MUC8 in the glandular excretory ducts and also did not react in glandular acini. Salivary stones demonstrated a characteristic distribution pattern of MUC8 that differed between parotid and submandibular salivary stones. The mean MUC8 concentration was 71.06 ng/mL in female and 33.21 ng/mL in male subjects (p = 0.156). Saliva from the side with salivary calculi contained significantly (15-fold) higher MUC8 concentration levels than saliva from the healthy side (p = 0.0005). MUC8 concentration in salivary stones varied from 4.59 ng/mL to 202.83 ng/mL. In females, the MUC8 concentration in salivary stones was significantly (2.3-fold) higher, with an average of 82.84 ng/mL compared to 25.27 ng/mL in male patients (p = 0.034). MUC8 is secreted in the excretory duct system of salivary glands and released into saliva. Importantly, MUC8 salivary concentrations vary greatly between individuals. In addition, the MUC8 concentration is gender-dependent (♀ > ♂). In the context of salivary stone diseases, MUC8 is highly secreted in saliva. The findings support a role for MUC8 in the context of inflammatory events and salivary stone formation. The findings allow conclusions on a gender-dependent component of MUC8.

Gold Nanoparticles: A Powerful Tool to Visualize Proteins on Ordered Mesoporous Silica and for the Realization of Theranostic Nanobioconjugates

Ordered mesoporous silica (OMS) is a very interesting nanostructured material for the design and engineering of new target and controlled drug-delivery systems. Particularly relevant is the interaction between OMS and proteins. Large pores (6–9 nm) micrometric particles can be used for the realization of a drug depot system where therapeutic proteins are adsorbed either inside the mesopores or on the external surface. Small pores (1–2 nm) mesoporous silica nanoparticles (MSNs), can be injected in the blood stream. In the latter case, therapeutic proteins are mainly adsorbed on the MSNs’ external surface. Whenever a protein-OMS conjugate is prepared, a diagnostic method to locate the protein either on the internal or the external silica surface is of utmost importance. To visualize the fine localization of proteins adsorbed in mesoporous silica micro- and nanoparticles, we have employed specific transmission electron microscopy (TEM) analytical strategies based on the use of gold nanoparticles (GNPs) conjugates. GNPs are gaining in popularity, representing a fundamental tool to design future applications of MSNs in nanomedicine by realizing theranostic nanobioconjugates. It may be pointed out that we are at the very beginning of a new age of the nanomaterial science: the “mesoporous golden age„.