Decayed deciduous teeth have been usually discarded once the pulp tissue could be damaged and the activity of stem cells compromised. These findings show that stem cells from carious deciduous teeth can be applicable source for cell-based therapies in tissue regeneration.
The sterilization of scaffolds is an essential step for tissue engineering in vitro and, mainly, clinical biomaterial use. However, this process can cause changes in the structure and surface of the scaffolds. Therefore, the objective of this study was to investigate the effect of sterilization by ethanol, ultraviolet radiation (UVR) or antimicrobial solution (AMS) on poly(lactide-co-glycolide) (PLGA) scaffolds produced by the electrospinning technique. The properties of nanofibers and the cellular adhesion of mesenchymal stem cells to the scaffolds were analyzed after the treatments. All methods generated sterile scaffolds but showed some kind of damage to the scaffolds. Ethanol and AMS caused changes in the morphology and scaffold dimensions, which were not observed when using the UVR method. However, UVR caused a greater reduction in polymeric molecular weight, which increased proportionally with exposure time of treatment. Nanofibers sterilized with AMS for 1 h and 2 h showed greater cellular adhesion than the other methods, demonstrating their potential as a method for sterilizing PLGA nanofibers.
The association of stem cells (SCs) with biomaterials promises to be the protagonist for future regenerative medicine in the treatment of tissue and organ lesions. Stem cells were cultivated in scaffolds constructed by the electrospinning technique, using poly-D,L-lactic acid (PDLLA) associated or not with Spirulina biomass (PDLLA/Sp), which has bioactive components of interest for tissue engineering (TE). Physicochemical analyses were performed, such as morphology, fiber diameter, degradability, residual solvent, roughness, contact angle with water, among others. SCs adhesion, proliferation and scaffold cytotoxicity were also evaluated. Nanofibers without beads and with characteristics similar to the natural extracellular matrix (ECM) in terms of mechanical and topographical properties were obtained. In biological tests it was found that SCs adhered more and had greater viability in the PDLLA/Sp molds, when compared with the PDLLA scaffolds. The scaffolds were shown to be atoxic for the SCs. It can be concluded that the scaffolds developed in this work have the characteristics to be a new biomaterial suitable for use in TE.
Background
Patients who start combination antiretroviral therapy (cART) during primary human immunodeficiency virus type 1 (HIV-1) infection show a smaller HIV-1 latent reservoir, less immune activation, and less viral diversity compared to patients who start cART during chronic infection. We conducted a pilot study to determine whether these properties would allow sustained virological suppression after simplification of cART to dolutegravir monotherapy.
Methods
EARLY-SIMPLIFIED is a randomized, open-label, noninferiority trial. Patients who started cART <180 days after a documented primary HIV-1 infection and had an HIV-1 RNA <50 copies/mL plasma for at least 48 weeks were randomized (2:1) to monotherapy with dolutegravir 50 mg once daily or to continuation of cART. The primary efficacy endpoint was the proportion of patients with <50 HIV-1 RNA copies/mL on or before week 48; noninferiority margin 10%.
Results
Of the 101 patients randomized, 68 were assigned to simplification to dolutegravir monotherapy and 33 to continuation of cART. At week 48 in the per-protocol population, 67/67 (100%) had virological response in the dolutegravir monotherapy group vs 32/32 (100%) in the cART group (difference, 0.00%; 95% confidence interval, –100%, 4.76%). This showed noninferiority of the dolutegravir monotherapy at the prespecified level.
Conclusion
In this pilot study consisting of patients who initiated cART during primary HIV-1 infection and had <50 HIV-1 RNA copies/mL for at least 48 weeks, monotherapy with once-daily dolutegravir was noninferior to cART. Our results suggest that future simplification studies should use a stratification according to time of HIV infection and start of first cART.
Clinical Trials Registration
NCT02551523.
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