Potential of Fibrin Glue and Mesenchymal Stem Cells (MSCs) to Regenerate Nerve Injuries: A Systematic Review.

Cell-based therapy is a promising treatment to favor tissue healing through less invasive strategies. Mesenchymal stem cells (MSCs) highlighted as potential candidates due to their angiogenic, anti-apoptotic and immunomodulatory properties, in addition to their ability to differentiate into several specialized cell lines. Cells can be carried through a biological delivery system, such as fibrin glue, which acts as a temporary matrix that favors cell-matrix interactions and allows local and paracrine functions of MSCs. Thus, the aim of this systematic review was to evaluate the potential of fibrin glue combined with MSCs in nerve regeneration. The bibliographic search was performed in the PubMed/MEDLINE, Web of Science and Embase databases, using the descriptors ("fibrin sealant" OR "fibrin glue") AND "stem cells" AND "nerve regeneration", considering articles published until 2021. To compose this review, 13 in vivo studies were selected, according to the eligibility criteria. MSCs favored axonal regeneration, remyelination of nerve fibers, as well as promoted an increase in the number of myelinated fibers, myelin sheath thickness, number of axons and expression of growth factors, with significant improvement in motor function recovery. This systematic review showed clear evidence that fibrin glue combined with MSCs has the potential to regenerate nervous system lesions.

Solutions and Gels Containing a Sugarcane-Derived Cystatin (CaneCPI-5) Reduce Enamel and Dentin Erosion in vitro.

The effect of solutions and gels containing a sugarcane-derived cystatin (CaneCPI-5) on the protection against enamel and dentin erosion in vitro was evaluated. Bovine enamel and dentin specimens were divided into 2 groups (n = 135 and 153/group for enamel and dentin, respectively) that were treated with solutions or chitosan gels containing 0.1 or 0.25 mg/mL CaneCPI-5. The positive controls for solutions and gels were Elmex Erosion Protection™ solution and NaF gel (12,300 ppm F), respectively. Deionized water and chitosan gel served as controls, respectively. The solutions were first applied on the specimens for 1 min and the gels for 4 min. Stimulated saliva was collected from 3 donors and used to form a 2-h acquired pellicle on the specimens. Then, the specimens were submitted to an erosive pH cycling protocol 4 times/day for 7 days (0.1% citric acid pH 2.5/90 s, artificial saliva/2 h, and artificial saliva overnight). The solutions and gels were applied again during pH cycling, 2 times/day for 1 min and 4 min, respectively, after the first and last erosive challenges. Enamel and dentin losses (µm) were assessed by contact profilometry. Data were analyzed by 2-way ANOVA and Tukey's test (p < 0.05). All the treatments significantly reduced enamel and dentin loss in comparison with controls. Both CaneCPI-5 concentrations had a similar protective effect against enamel erosion, but only the higher concentration was as effective against dentin erosion as the positive control. Regarding the vehicles, only the 0.1 mg/mL gel performed worse than the positive control for dentin. CaneCPI-5 reduced enamel and dentin erosion to a similar extent as the fluoride-containing vehicles. However, dentin requires higher CaneCPI-5 concentrations, in the case of gels. Solutions or gels containing CaneCPI-5 might be a new approach to protect against dental erosion.

Effects of Therapy with Fibrin Glue combined with Mesenchymal Stem Cells (MSCs) on Bone Regeneration: A Systematic Review.

Cell therapy strategies using mesenchymal stem cells (MSCs) carried in fibrin glue have shown promising results in regenerative medicine. MSCs are crucial for tissue healing because they have angiogenic, anti-apoptotic and immunomodulatory properties, in addition to the ability to differentiate into several specialized cell lines. Fibrin sealant or fibrin glue is a natural polymer involved in the coagulation process. Fibrin glue provides a temporary structure that favors angiogenesis, extracellular matrix deposition and cell-matrix interactions. Additionally, fibrin glue maintains the local and paracrine functions of MSCs, providing tissue regeneration through less invasive clinical procedures. Thus, the objective of this systematic review was to assess the potential of fibrin glue combined with MSCs in bone or cartilage regeneration. The bibliographic search was performed in the PubMed/MEDLINE, LILACS and Embase databases, using the descriptors ("fibrin sealant" OR "fibrin glue") AND "stem cells" AND "bone regeneration", considering articles published until 2021. In this case, 12 preclinical and five clinical studies were selected to compose this review, according to the eligibility criteria. In preclinical studies, fibrin glue loaded with MSCs, alone or associated with bone substitute, significantly favored bone defects regeneration compared to scaffold without cells. Similarly, fibrin glue loaded with MSCs presented considerable potential to regenerate joint cartilage injuries and multiple bone fractures, with significant improvement in clinical parameters and absence of postoperative complications. Therefore, there is clear evidence in the literature that fibrin glue loaded with MSCs, alone or combined with bone substitute, is a promising strategy for treating lesions in bone or cartilaginous tissue.

Saliva as a diagnostic tool for dental caries, periodontal disease and cancer: is there a need for more biomarkers?

Introduction: A biomarker is a biological indicator of normal or pathogenic processes. Identification of biomarkers is useful for the prevention, diagnosis and prognosis of diseases as well as for monitoring the progression of pathological disorders. Several types of molecules present in biological fluids can act as biomarkers such as DNA, coding and non-coding RNA, lipids, metabolites, proteins and even microbes. In this context, saliva emerges as a useful diagnostic tool for the detection of biomarkers involved with oral and systemic diseases, since it reflects the pathophysiological conditions of the organism and allows early, rapid, practical and noninvasive detection of biomarkers.Areas covered: This review discusses the properties of saliva as a diagnostic tool and addresses the main identified biomarkers related to dental caries, periodontal disease, head and neck cancer and other types of cancer of considerable incidence among the world population.Expert commentary: Despite extensive efforts which have been directed toward the identification of one or a combination of biomarkers with good predictive values for the early detection of dental caries, periodontal disease and cancer, these biomarkers still need validation before chairside point-of-care devices can be widely used in the clinic.

Anticaries Potential of Low Fluoride Dentifrices Found in The Brazilian Market

Abstract Low-fluoride (F) dentifrices (<600 µg F/g) are widely available worldwide, but evidence to recommend the use of such dentifrices, with either regular or improved formulations, is still lacking. Therefore, the aim of this study was to evaluate the anticaries potential of low-F dentifrices found in the Brazilian market, using a validated and tested pH-cycling model. Enamel blocks were selected by surface hardness (SH) and randomized into four treatment groups (n=12): non-F dentifrice (negative control), low-F dentifrice (500 μg F/g), low-F acidulated dentifrice (550 μg F/g) and 1,100 μg F/g dentifrice (positive control). The blocks were subjected to pH-cycling regimen for 8 days and were treated 2x/day with dentifrice slurries prepared in water (1:3, w/v). The pH of the slurries was checked, and only the acidulated one had low pH. After the pH cycling, SH was again determined and the percentage of surface hardness loss was calculated as indicator of demineralization. Loosely- and firmly-bound F concentrations in enamel were also determined. The 1,100 μg F/g dentifrice was more effective than the low-F ones to reduce enamel demineralization and was the only one that differed from the non-F (p<0.05). All F dentifrices formed higher concentration of loosely-bound F on enamel than the non-F (p<0.05), but the 1,100 μg F/g was the only one that differed from the non-F in the ability to form firmly-bound F. The findings suggest that the low-F dentifrices available in the Brazilian market, irrespective of their formulation, do not have anticaries potential.

Resumo Dentifrícios de baixa concentração de fluoreto (F) (< 600 µg F/g) estão amplamente disponíveis no mundo, mas ainda não há evidência para recomendar seu uso, quer seja em formulações regulares ou melhoradas. Assim, o objetivo deste estudo foi avaliar o potencial anticárie de dentifrícios de baixa concentração de fluoreto encontrados no mercado brasileiro, utilizando um modelo de ciclagens de pH validado e testado. Blocos de esmalte bovinos foram selecionados pela dureza de superfície e randomizados em quatro grupos (n=12): dentifrício sem fluoreto (controle negativo), dentifrício de baixa concentração de fluoreto (500 μg F/g), dentifrício acidulado de baixa concentração de fluoreto (550 μg F/g) e dentifrício de 1100 μg F/g (controle positivo). Os blocos foram submetidos ao regime de ciclagem de pH por 8 dias e tratados 2 x/dia com suspensões aquosas dos dentifrícios (1:3 p/v). O pH das suspensões foi checado, e apenas o acidulado tinha baixo pH. Após a ciclagem de pH, a dureza de superfície foi novamente determinada e a porcentagem de perda de dureza foi calculada como indicador de demineralização. As concentrações de fluoreto fracamente e firmemente ligado ao esmalte também foram determinadas. O dentifrício de 1.100 μg F/g foi mais efetivo do que os de baixa concentração na redução da desmineralização do esmalte e foi o único que diferiu significativamente do não fluoretado (p<0,05). Todos os dentifrícios fluoretados foram capazes de formar maiores concentrações de fluoreto fracamente ligado ao esmalte do que o não fluoretado (p<0,05), mas o de 1.100 μg F/g foi o único que diferiu do não fluoretado na capacidade de formar fluoreto firmemente ligado ao esmalte. Os resultados sugerem que dentifrícios de baixa concentração de fluoreto disponíveis no mercado brasileiro, independentemente da formulação, não têm potencial anticárie.