In order to understand how omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplements affect breast cancer prevention and treatment, a systematic review of articles published in the last 5 years in two databases was performed. Of the 679 articles identified, only 27 were included and examined based on five topics, taking into account: the induction type of the breast cancer used in animal models; the characteristics of the induction model by cell transplantation; the experimental design of the ω-3 supplementation—combined or not with a treatment antitumor drug; the fatty acids (FAs) composition used; the analysis of the studies’ outcomes. There are diverse and well-established animal models of breast cancer in the literature, with very relevant histological and molecular similarities depending on the specific objective of the study, such as whether the method of tumor induction was transgenic, by cell transplantation, or by oncogenic drugs. The analyses of outcomes were mainly focused on monitoring tumor growth, body/tumor weight, and molecular, genetic, or histological analyses, and few studies evaluated latency, survival, or metastases. The best results occurred when supplementation with ω-3 PUFA was associated with antitumor drugs, especially in the analysis of metastases and volume/weight of tumors or when the supplementation was started early and maintained for a long time. However, the beneficial effect of ω-3 PUFA supplementation when not associated with an antitumor agent remains unclear.

BACKGROUND Bone marrow transplantation (BMT) can be applied to both hematopoietic and nonhematopoietic diseases; nonetheless, it still comes with a number of challenges and limitations that contribute to treatment failure. Bearing this in mind, a possible way to increase the success rate of BMT would be cotransplantation of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) to improve the bone marrow niche and secrete molecules that enhance the hematopoietic engraftment. AIM To analyze HSC and MSC characteristics and their interactions through cotransplantation in murine models. METHODS We searched for original articles indexed in PubMed and Scopus during the last decade that used HSC and MSC cotransplantation and in vivo BMT in animal models while evaluating cell engraftment. We excluded in vitro studies or studies that involved graft versus host disease or other hematological diseases and publications in languages other than English. In PubMed, we initially identified 555 articles and after selection, only 12 were chosen. In Scopus, 2010 were identified, and six were left after the screening and eligibility process. RESULTS Of the 2565 articles found in the databases, only 18 original studies met the eligibility criteria. HSC distribution by source showed similar ratios, with human umbilical cord blood or animal bone marrow being administered mainly with a dose of 1 × 10 7 cells by intravenous or intrabone routes. However, MSCs had a high prevalence of human donors with a variety of sources (umbilical cord blood, bone marrow, tonsil, adipose tissue or fetal lung), using a lower dose, mainly 10 6 cells and ranging 10 4 to 1.5 × 10 7 cells, utilizing the same routes. MSCs were characterized prior to administration in almost every experiment. The recipient used was mostly immunodeficient mice submitted to low-dose irradiation or chemotherapy. The main technique of engraftment for HSC and MSC cotransplantation evaluation was chimerism, followed by hematopoietic reconstitution and survival analysis. Besides the engraftment, homing and cellularity were also evaluated in some studies. CONCLUSION The preclinical findings validate the potential of MSCs to enable HSC engraftment in vivo in both xenogeneic and allogeneic hematopoietic cell transplantation animal models, in the absence of toxicity.

Bone marrow transplantation is a treatment for a variety of hematological and non-hematological diseases. For the transplant success, it is mandatory to have a thriving engraftment of transplanted cells, which directly depends on their homing. The present study proposes an alternative method to evaluate the homing and engraftment of hematopoietic stem cells using bioluminescence imaging and inductively coupled plasma mass spectrometry (ICP-MS) associated with superparamagnetic iron oxide nanoparticles. We have identified an enriched population of hematopoietic stem cells in the bone marrow following the administration of Fluorouracil (5-FU). Lately, the cell labeling with nanoparticles displayed the greatest internalization status when treated with 30 µg Fe/mL. The quantification by ICP-MS evaluate the stem cells homing by identifying 3.95 ± 0.37 µg Fe/mL in the control and 6.61 ± 0.84 µg Fe/mL in the bone marrow of transplanted animals. In addition, 2.14 ± 0.66 mg Fe/g in the spleen of the control group and 2.17 ± 0.59 mg Fe/g in the spleen of the experimental group was also measured. Moreover, the bioluminescence imaging provided the follow up on the hematopoietic stem cells behavior by monitoring their distribution by the bioluminescence signal. Lastly, the blood count enabled the monitoring of animal hematopoietic reconstitution and ensured the transplantation effectiveness.

BACKGROUND Induced pluripotent stem cells (iPSCs) show great ability to differentiate into any tissue, making them attractive candidates for pathophysiological investigations. The rise of organ-on-a-chip technology in the past century has introduced a novel way to make in vitro cell cultures that more closely resemble their in vivo environments, both structural and functionally. The literature still lacks consensus on the best conditions to mimic the blood-brain barrier (BBB) for drug screening and other personalized therapies. The development of models based on BBB-on-a-chip using iPSCs is promising and is a potential alternative to the use of animals in research. AIM To analyze the literature for BBB models on-a-chip involving iPSCs, describe the microdevices, the BBB in vitro construction, and applications. METHODS We searched for original articles indexed in PubMed and Scopus that used iPSCs to mimic the BBB and its microenvironment in microfluidic devices. Thirty articles were identified, wherein only 14 articles were finally selected according to the inclusion and exclusion criteria. Data compiled from the selected articles were organized into four topics: (1) Microfluidic devices design and fabrication; (2) characteristics of the iPSCs used in the BBB model and their differentiation conditions; (3) BBB-on-a-chip reconstruction process; and (4) applications of BBB microfluidic three-dimensional models using iPSCs. RESULTS This study showed that BBB models with iPSCs in microdevices are quite novel in scientific research. Important technological advances in this area regarding the use of commercial BBB-on-a-chip were identified in the most recent articles by different research groups. Conventional polydimethylsiloxane was the most used material to fabricate in-house chips (57%), whereas few studies (14.3%) adopted polymethylmethacrylate. Half the models were constructed using a porous membrane made of diverse materials to separate the channels. iPSC sources were divergent among the studies, but the main line used was IMR90-C4 from human fetal lung fibroblast (41.2%). The cells were differentiated through diverse and complex processes either to endothelial or neural cells, wherein only one study promoted differentiation inside the chip. The construction process of the BBB-on-a-chip involved previous coating mostly with fibronectin/collagen IV (39.3%), followed by cell seeding in single cultures (36%) or co-cultures (64%) under controlled conditions, aimed at developing an in vitro BBB that mimics the human BBB for future applications. CONCLUSION This review evidenced technological advances in the construction of BBB models using iPSCs. Nonetheless, a definitive BBB-on-a-chip has not yet been achieved, hindering the applicability of the models.