Comparing the healing properties of intra-articular injection of human dental pulp stem cells and cell-free-secretome on induced knee osteoarthritis in male rats.

OBJECTIVE: Osteoarthritis (OA) is a common and painful joint disease with multifactorial causes. Stem cells, due to their high ability to reproduce and differentiate, have created a new horizon in tissue engineering of cartilage and bone. Secretions are one of the new therapies that can be used with stem cells or separately. This study aimed to compare the healing effects of human dental pulp stem cells, cell-free secretome, and human dental pulp mesenchymal stem cells with secretome in the induced OA in male rats. METHODS: Dental pulp mesenchymal stem cells were isolated and prepared from human dental pulp. The collagenase type II was injected into the knee of twenty-five male Sprague-Dawley rats, and after 10 weeks, OA was confirmed. Rats were divided into five groups (n = 5): 1) Human dental pulp stem cells plus secretome (HDP+Sec); 2) Human dental pulp stem cells (HDP); 3) Secretome (Sec); 4) Hyalgan as the positive control (Hya); 5) No treatment as the negative control (Ctrl). After 12 weeks since OA was confirmed, the healing process was examined by histopathology and radiology evaluations. RESULTS: Histopathological evaluations, radiological assessments, and matrix indexes in three treatment groups significantly improved compared to the Ctrl and Hya groups. Surface in HDP+Sec was significantly better than the Ctrl group. In radiological evaluations, a significant decrease in OA was observed in the three treatment groups in comparison with the Ctrl groups. There was no significant difference between the treatment groups in any radiological and histopathological evaluations. HDP + Sec group slightly records better results compared to Sec or HDP treatment groups. CONCLUSION: It was concluded that human dental pulp stem cells and their secretome promote cartilage regeneration due to their cell protective potential as well as matrix degeneration reduction capacity.

Molecular identification of Malassezia species isolated from neonates hospitalized in Neonatal intensive care units and their mothers.

Background and Purpose: Given the important role of Malassezia spp. in skin diseases and other associated infections in neonates, this study aimed to investigate the presence and frequency of Malassezia spp. in the skin of neonates hospitalized in neonatal intensive care units and their mothers using culture and accurate molecular-based methods. Materials and Methods: In total, 205 samples were collected from 130 neonates (>4-day-old) and 75 mothers. Isolation of Malassezia spp. from the skin was performed using Leeming-Notman agar and modified Dixon agar media. To compare the Malassezia microflora on the skin of the neonates and their mothers, a polymerase chain reaction-sequencing method was performed for spp. identification of 92 isolates obtained from neonates and their mothers. Moreover, possible associated risk factors for the colonization of Malassezia spp. on the skin were recorded. Results: Cultures from 62.3% of neonates and 77.3% of mothers were positive for Malassezia spp. growth. Malassezia globosa was the most prevalent isolated spp. found in the skin of the study population. It is noteworthy that a rare Malassezia spp., Malassezia arunalokei, was isolated from the skin of one neonate. There was a 76% similarity between the mother-neonate isolate sequences results. The statistical analysis showed that the type of feeding is a significant (P<0.001) associated factor for Malassezia skin colonization. Conclusion: The findings support the hypothesis that the colonization of Malassezia in neonates is significantly influenced by that of the mother, and this may be associated with breastfeeding.