Background: Posttransplant cell tracking, via stem cell labeling, is a crucial strategy for monitoring and maximizing benefits of cell-based therapies. The structures and functionalities of polysaccharides, proteins, and lipids allow their utilization in nanotechnology systems. Materials and methods: In the present study, we analyzed the potential benefit of curcumin-loaded nanoparticles (NPC) using Vero cells (in vitro) and NPC-labeled adipose-derived mesenchymal stem cells (NPC-ADMSCs) (in vivo) in myocardial infarction and sciatic nerve crush preclinical models. Thereafter, transplantation, histological examination, real time imaging, and assessment of tissue regeneration were done. Results: Transplanted NPC-ADMSCs were clearly identified and revealed potential benefit when used in cell tracking. Conclusion: This approach may have broad applications in modeling labeled transplanted cells and in developing improved stem cell therapeutic strategies.

Biological scaffolds have become an attractive approach for repairing the infarcted myocardium and have been shown to facilitate constructive remodeling in injured tissues. This study aimed to investigate the possible utilization of bacterial cellulose (BC) membrane patches containing cocultured cells to limit myocardial postinfarction pathology. Myocardial infarction (MI) was induced by ligating the left anterior descending coronary artery in 45 Wistar rats, and patches with or without cells were attached to the hearts. After one week, the animals underwent echocardiography to assess for ejection fraction and left ventricular end-diastolic and end-systolic volumes. Following patch formation, the cocultured cells retained viability of >90% over 14 days in culture. The patch was applied to the myocardial surface of the infarcted area after staying 14 days in culture. Interestingly, the BC membrane without cellular treatment showed higher preservation of cardiac dimensions; however, we did not observe improvement in the left ventricular ejection fraction of this group compared to coculture-treated membranes. Our results demonstrated an important role for BC in supporting cells known to produce cardioprotective soluble factors and may thus provide effective future therapeutic outcomes for patients suffering from ischemic heart disease.

Discarded tissues, like human amniotic membranes and adipose tissue, were investigated for the application of Decellularized Human Amniotic Membrane (DAM) as a viable scaffold for transplantation of Adipose-derived stromal cells (ASCs) in bone regeneration of non-healing calvarial defects in rats. Amniotic membrane was decellularized to provide a scaffold for male Wistar rats ASCs expansion and transplantation. ASCs osteoinduction in vitro promoted the deposition of a mineralized bone-like matrix by ASCs, as calcified globular accretions associated with the cells on the DAM surface and inside the collagenous matrix. Non-healing calvarial defects on male Wistar rats were randomly divided in control without treatment, treatment with four layers of DAM, or four layers of DAM associated with ASCs. After 12 weeks, tissue blocks were examined by micro-computed tomography and histology. DAM promoted osteoconduction by increasing the collagenous matrix on both DAM treatments. DAM with ASCs stimulated bone deposition, demonstrated by a higher percentage of bone volume and trabecular bone number, compared to control. Besides the osteogenic capacity in vitro, ASCs stimulated the healing of calvarial defects with significant DAM graft incorporation concomitant with higher host bone deposition. The enhanced in vivo bone regeneration by undifferentiated ASCs loaded onto DAM confirmed the potential of an easily collected autologous cell source associated with a broadly available collagenous matrix in tissue engineering.

Objective. Achilles tendon pathologies occur frequently and have a significant socioeconomic impact. Currently, there is no evidence on the best treatment for these pathologies. Cell therapy has been studied in several animal models, and encouraging results have been observed with respect to tissue regeneration. This study is aimed at evaluating the functional and histological effects of bone marrow stem cell or platelet-rich plasma implantation compared to eccentric training in the treatment of Achilles tendinopathy in rats.Methods.Fourty-one male Wistar rats received collagenase injections into their bilateral Achilles tendons (collagenase-induced tendinopathy model). The rats were randomly divided into four groups: stem cells (SC), platelet-rich plasma (PRP), stem cells+platelet-rich plasma (SC+PRP), and control (eccentric training (ET)). After 4 weeks, the Achilles tendons were excised and subjected to biomechanical and histological analyses (Sirius red and hematoxylin-eosin staining).Results.Biomechanical assessments revealed no differences among the groups in ultimate tensile strength or yield strength of the tendons (p=0.157), but there were significant differences in the elastic modulus (MPa;p=0.044) and maximum tensile deformation (p=0.005). The PRP group showed the greatest maximum deformation, and the SC group showed the highest Young’s modulus (elasticity) measurement. In histological analysis (hematoxylin-eosin and Sirius red staining), there were no differences among the groups.Conclusion.PRP and SC+PRP yielded better biomechanical results than eccentric training, showing that these treatments offer better tend function outcomes. This theoretical rationale for the belief that cell therapies can serve as viable alternatives to current treatments chronic fibrotic opens the door for opportunities to continue this research.

Background: Tracheal lesions are pathologies derived from the most diverse insults that can result in a fatal outcome. Despite the number of techniques designed for the treatment, a limiting factor is the extent of the extraction. Therefore, strategies with biomaterials can restructure tissues and maintain the organ’s functionality, like decellularized Wharton’s jelly (WJ) as a scaffold. The aim is to analyze the capacity of tracheal tissue regeneration after the implantation of decellularized WJ in rabbits submitted to a tracheal defect. Methods: An in vivo experimental study was undertaken using twenty rabbits separated into two groups (n = 10). Group 1 submitted to a tracheal defect, group 2 tracheal defect, and implantation of decellularized WJ. The analyses were performed 30 days after surgery through immunohistochemistry. Results: Inner tracheal area diameter (p = 0.643) didn’t show significance. Collagen type I, III, and Aggrecan highlighted no significant difference between the groups (both collagens with p = 0.445 and the Aggrecan p = 0.4). Conclusion: The scaffold appears to fit as a heterologous implant and did not trigger reactions such as rejection or extrusion of the material into the recipient. However, these results suggested that although the WJ matrix presents several characteristics as a biomaterial for tissue regeneration, it did not display histopathological benefits in trachea tissue regeneration.