Cell Therapy Based on Gingiva-Derived Mesenchymal Stem Cells Seeded in a Xenogeneic Collagen Matrix for Root Coverage of RT1 Gingival Lesions: An In Vivo Experimental Study.

(1) Background: To investigate the effect of a xenogeneic collagen matrix (CMX) seeded with autologous gingiva-derived mesenchymal cells (GMSCs) when combined with a coronally advanced flap (CAF) in the treatment of localized gingival recession type 1 (RT1). (2) Methods: Dehiscence-type defects were created in seven dogs. GMSCs were isolated, transfected with a vector carrying green fluorescent protein (GFP) and expanded. Once chronified, the defects were randomly treated with (1) CAF plus the combination of CMX and GFP+ GMSCs, (2) CAF plus CMX with autologous fibroblasts, (3) CAF plus CMX and (4) CAF alone. Histological and clinical outcomes at 2- and 6-week healing periods were analyzed and compared among groups. (3) Results: Histologically, the addition of autologous cells to the CMX resulted in reduced inflammation and a variable degree of new cementum/bone formation. CMX plus GMSCs resulted in greater mean recession reduction (1.42; SD = 1.88 mm) and percentage of teeth with recession reduction of ≥2 mm (57%) when compared to the other groups, although these differences were not statistically significant. (4) Conclusions: The histometric and clinical results indicated a positive trend favouring the combination of CMX and GMSCs with the CAF when compared to the groups without cells, although these differences were not statistically significant.

Periodontal regeneration using a xenogeneic bone substitute seeded with autologous periodontal ligament-derived mesenchymal stem cells: A 12-month quasi-randomized controlled pilot clinical trial.

AIM: To evaluate the safety and efficacy of autologous periodontal ligament-derived mesenchymal stem cells (PDL-MSCs) embedded in a xenogeneic bone substitute (XBS) for the regenerative treatment of intra-bony periodontal defects. MATERIAL AND METHODS: This quasi-randomized controlled pilot phase II clinical trial included patients requiring a tooth extraction and presence of one intra-bony lesion (1-2 walls). Patients were allocated to either the experimental (XBS + 10 × 106 PDL-MSCs/100 mg) or the control group (XBS). Clinical and radiographical parameters were recorded at baseline, 6, 9 and 12 months. The presence of adverse events was also evaluated. Chi-square, Student's t test, Mann-Whitney U, repeated-measures ANOVA and regression models were used. RESULTS: Twenty patients were included. No serious adverse events were reported. Patients in the experimental group (n = 9) showed greater clinical attachment level (CAL) gain (1.44, standard deviation [SD] = 1.87) and probing pocket depth (PPD) reduction (2.33, SD = 1.32) than the control group (n = 10; CAL gain = 0.88, SD = 1.68, and PPD reduction = 2.10, SD = 2.46), without statistically significant differences. CONCLUSION: The application of PDL-MSCs to XBS for the treatment of one- to two-wall intra-bony lesions was safe and resulted in low postoperative morbidity and appropriate healing, although its additional benefit, when compared with the XBS alone, was not demonstrated.

Cell therapy with allogenic canine periodontal ligament-derived cells in periodontal regeneration of critical size defects.

AIM: The objective of this in vivo experimental study to evaluate the regenerative potential of a cell therapy combining allogenic periodontal ligament-derived cells within a xenogeneic bone substitute in a similar experimental model. METHODS: In nine beagle dogs, critical size 6-mm supra-alveolar periodontal defects were created around the PIII and PIV. The resulting supra-alveolar defects were randomly treated with either 1.4 × 106 allogenic canine periodontal ligament-derived cells seeded on de-proteinized bovine bone mineral with 10% collagen (DBBM-C) (test group) or DBBM-C without cells (control group). Specimens were obtained at 3 months, and histological outcomes were studied. RESULTS: The histological analysis showed that total furcation closure occurred very seldom in both groups, being the extent of periodontal regeneration located in the apical third of the defect. The calculated amount of periodontal regeneration at the furcation area was comparable in both the test and control groups (1.93 ± 1.14 mm (17%) versus 2.35 ± 1.74 mm (22%), respectively (p = .37). Similarly, there were no significant differences in the amount of new cementum formation 4.49 ± 1.56 mm (41%) versus 4.97 ± 1.05 mm (47%), respectively (p = .45). CONCLUSIONS: This experimental study was unable to demonstrate the added value of allogenic cell therapy in supra-crestal periodontal regeneration.

Comparison of periodontal ligament and gingiva-derived mesenchymal stem cells for regenerative therapies.

OBJECTIVES: Tissue-engineering therapies using undifferentiated mesenchymal cells (MSCs) from intra-oral origin have been tested in experimental animals. This experimental study compared the characteristics of undifferentiated mesenchymal stem cells from either periodontal ligament or gingival origin, aiming to establish the basis for the future use of these cells on regenerative therapies. MATERIALS AND METHODS: Gingiva-derived mesenchymal stem cells (GMSCs) were obtained from de-epithelialized gingival biopsies, enzymatically digested and expanded in conditions of exponential growth. Their growth characteristics, phenotype, and differentiation ability were compared with those of periodontal ligament-derived mesenchymal stem cells (PDLMSCs). RESULTS: Both periodontal ligament- and gingiva-derived cells displayed a MSC-like phenotype and were able to differentiate into osteoblasts, chondroblasts, and adipocytes. These cells were genetically stable following in vitro expansion and did not generate tumors when implanted in immunocompromised mice. Furthermore, under suboptimal growth conditions, GMSCs proliferated with higher rates than PDLMSCs. CONCLUSIONS: Stem cells derived from gingival biopsies represent bona fide MSCs and have demonstrated genetic stability and lack of tumorigenicity. CLINICAL RELEVANCE: Gingiva-derived MSCs may represent an accessible source of messenchymal stem cells to be used in future periodontal regenerative therapies.

Diagnóstico diferencial de infecciones sistémicas por Trichosporon Beigelii / Differential diagnostic of sistemic infections by Trichoporon Beigelii

Trichosporon beigelii es un hongo que se aísla del suelo y aguas en zonas tropicales y ocasionalmente se encuentra como parte de la flora micótica de piel, uñas y boca. Hasta 1970 la importancia médica de este agente se relegó a una micosis superficial en el pelo, caracterizada por la producción de unas masas blanquecinas, de donde deriva el nombre de "Piedra blanca." Actualmente este agente se relaciona con infecciones sistémicas o localizadas en algunos órganos en pacientes con algún grado de inmunodeficiencia o con cuadros malignos bajo tratamiento, en los cuales se presentan leucopenias importantes. Otros factores predisponentes son el tratamiento con corticosteroides, la implantación de prótesis en válvulas cardiacas, la hemacromatosis y el SIDA. Se describe el caso de una niña de 3 meses de edad, con un absceso hepático del cual se tomó una biopsia por punción, que mostró lesiones caracterizadas por un infiltrado inflamatorio con predominio de células mononucleares, detritus celulares asociados con masas de micelio septado, artrosporado, blastosporas, algunas gemando y otras formando cadenas de pseudomicelio. Del cultivo de ese material se aisló Trichosporon beigelii. Histopatológicamente esta micosis se puede confunir con Candida, Aspergillus y Geotrichum. También, las colonias en cultivos jóvenes en agar sangre tienden a confundirse con Candida. En todo caso la identificación de micelio, pseudomicelio, blastosporas y artrosporas orienta al diagnóstico.