Microfluidic-derived docosahexaenoic acid liposomes for glioblastoma therapy.

Glioblastoma (GBM) is the most prevalent malignant primary brain tumor and currently lacks an effective treatment. In this study, we utilized a microfluidic system to synthesize docosahexaenoic acid (DHA) liposomes for GBM therapy. DHA is an omega-3 (ω3) polyunsaturated fatty acid commonly found in human dietary consumption that has demonstrated potential in mitigating cancer development. The microfluidic device employed allowed for precise fine-tuning of the physicochemical properties of liposomes by adjusting the flow rate ratios, flow rates, and lipid concentrations. Three distinct-sized liposomes, ranging from 80 nm and 130 nm, were successfully internalized by GBM cells, and demonstrated the ability to reduce the viability of these cells. Furthermore, DHA liposomes proved significantly more efficient in triggering apoptotic pathways, through caspase-3-dependent mechanisms, in comparison to free DHA. Thus, the nanomedicine platform established in this study presents new opportunities in the development of liposome formulations incorporating ω3 fatty acids for cancer therapy.

Replication of natural surface topographies to generate advanced cell culture substrates.

Surface topographies of cell culture substrates can be used to generate in vitro cell culture environments similar to the in vivo cell niches. In vivo, the physical properties of the extracellular matrix (ECM), such as its topography, provide physical cues that play an important role in modulating cell function. Mimicking these properties remains a challenge to provide in vitro realistic environments for cells. Artificially generated substrates' topographies were used extensively to explore this important surface cue. More recently, the replication of natural surface topographies has been enabling to exploration of characteristics such as hierarchy and size scales relevant for cells as advanced biomimetic substrates. These substrates offer more realistic and mimetic environments regarding the topographies found in vivo. This review will highlight the use of natural surface topographies as a template to generate substrates for in-vitro cell culture. This review starts with an analysis of the main cell functions that can be regulated by the substrate's surface topography through cell-substrate interactions. Then, we will discuss research works wherein substrates for cell biology decorated with natural surface topographies were used and investigated regarding their influence on cellular performance. At the end of this review, we will highlight the advantages and challenges of the use of natural surface topographies as a template for the generation of advanced substrates for cell culture.

The biomimetic surface topography ofRubus fruticosusleaves stimulate the induction of osteogenic differentiation of rBMSCs.

The interaction between cells and biomaterials is essential for the success of biomedical applications in which the implantation of biomaterials in the human body is necessary. It has been demonstrated that material's chemical, mechanical, and structural properties can influence cell behaviour. The surface topography of biomaterials is a physical property that can have a major role in mediating cell-material interactions. This interaction can lead to different cell responses regarding cell motility, proliferation, migration, and even differentiation. The combination of biomaterials with mesenchymal stem cells (MSCs) for bone regeneration is a promising strategy to avoid the need for autologous transplant of bone. Surface topography was also associated with the capacity to control MSCs differentiation. Most of the topographies studied so far involve machine-generated surface topographies. Herein, our strategy differentiates from the above mentioned since we selected natural surface topographies that can modulate cell functions for regenerative medicine strategies.Rubus fruticosusleaf was the selected topography to be replicated in polycaprolactone (PCL) membranes through polydimethylsiloxane moulding and using soft lithography. Afterwards, rat bone marrow stem cells (rBMSCs) were seeded at the surface of the imprinted PCL membranes to characterize the bioactive potential of our biomimetic surface topography to drive rBMSCs differentiation into the osteogenic lineage. The selected surface topography in combination with the osteogenic inductive medium reveals having a synergistic effect promoting osteogenic differentiation.

Macrophage cell membrane infused biomimetic liposomes for glioblastoma targeted therapy.

Glioblastoma (GBM) is a highly aggressive malignant brain tumor currently without an effective treatment. Inspired by the recent advances in cell membrane biomimetic nanocarriers and by the key role of macrophages in GBM pathology, we developed macrophage membrane liposomes (MML) for GBM targeting. For the first time, it was assessed the role of macrophage polarization states in the effectiveness of these drug delivery systems. Interestingly, we observed that MML derived from M2 macrophages (M2 MML) presents higher uptake and increased delivery of the anticarcinogenic drug doxorubicin compared to M1 macrophage-derived nanocarriers (M1 MML) and control liposomes (CL). Moreover, the lowest uptake by macrophages of MML reveals promising immune escaping properties. Notably, M2 macrophages unveiled a higher expression of integrin CD49d, a crucial protein involved in the bilateral communication of macrophages with tumor cells. Therefore, our findings suggest the potential of using M2 macrophage membranes to develop novel nanocarriers targeting GBM.

Biomimetic surface topography as a potential modulator of macrophages inflammatory response to biomaterials.

The implantation of biomaterial devices can negatively impact the local microenvironment through several processes including the injury incurred during the implantation process and the associated host inflammatory response. Immune cell responses to implantable biomaterial devices mediate host-material interactions. Indeed, the immune system plays a central role in several biological processes required for the integration of biomaterials such as wound healing, tissue integration, inflammation, and foreign body reactions. The implant physicochemical properties such as size, shape, surface area, topography, and chemistry have been shown to provide cues to the immune system. Its induced immune-modulatory responses towards inflammatory or wound healing phenotypes can determine the success of the implant. In this work, we aim to evaluate the impact of some biomimetic surface topographies on macrophages' acute inflammatory response. For that, we selected 4 different biological surfaces to replicate through soft lithography on spin casting PCL membranes. Those topographies were: the surface of E. coli, S.eppidermidis and L929 cells cultured in polystyrene tissue culture disks, and an Eggshell membrane. We selected a model based on THP-1-derived macrophages to study the analysis of the expression of both pro-inflammatory and anti-inflammatory markers. Our results revealed that depending on the surface where these cells are seeded, they present different phenotypes. Macrophages present a M1-like phenotype when they are cultured on top of PCL membranes with the surface topography of E. coli and S. epidermidis. When cultured on membranes with L929 monolayers or Eggshell membrane surface topography, the macrophages present a M2-like phenotype. These results can be a significant advance in the development of new implantable biomaterial devices since they can help to modulate the inflammatory responses to implanted biomaterials by controlling their surface topography.

Erythrocyte-derived liposomes for the treatment of inflammatory diseases.

Effective and safe therapies to counteract persistent inflammation are necessary. We developed erythrocyte-derived liposomes (EDLs) with intrinsic anti-inflammatory activity. The EDLs were prepared using lipids extracted from erythrocyte membranes, which are rich in omega-3 fatty acids with several health benefits. Diclofenac, a widely used anti-inflammatory drug, was incorporated into EDLs in relevant therapeutic concentrations. The EDLs were also functionalised with folic acid to allow their active targeting of M1 macrophages, which are key players in inflammatory processes. In the presence of lipopolysaccharide (LPS)-stimulated macrophages, empty EDLs and EDLs incorporating diclofenac were able to reduce the levels of important pro-inflammatory cytokines, namely interleukin-6 (IL-6; ≈85% and 77%, respectively) and tumour necrosis factor-alpha (TNF-α; ≈64% and 72%, respectively). Strikingly, cytocompatible concentrations of EDLs presented similar effects to dexamethasone, a potent anti-inflammatory drug, in reducing IL-6 and TNF-α concentrations, demonstrating the EDLs potential to be used as bioactive carriers in the treatment of inflammatory diseases.

Biomimetic and cell-based nanocarriers - New strategies for brain tumor targeting.

In the last two decades no significant advances were achieved in the treatment of the most frequent and malignant types of brain tumors. The main difficulties in achieving progress are related to the incapacity to deliver drugs in therapeutic amounts into the central nervous system and the associated severe side effects. Indeed, to obtain effective treatments, the drugs should be able to cross the intended biological barriers and not being inactivated before reaching the specific therapeutic target. To overcome these challenges the development of synthetic nanocarriers has been widely explored for brain tumor treatment but unfortunately with no clinical translation until date. The use of cell-derived nanocarriers or biomimetic nanocarriers has been studied in the last few years, considering their innate bio-interfacing properties. The ability to carry therapeutic agents and a higher selectivity towards brain tumors would bring new hope for the development of safe and effective treatments. In this review, we explore the biological barriers that need to be crossed for effective delivery in brain tumors, and the types and properties of cell-based nanocarriers (extracellular vesicles and cell-membrane coated nanocarriers) currently under investigation.

Fabrication of biomimetic patterned PCL membranes mimicking the complexity of Rubus fruticosus leaves surface.

The development of bioresponsive interfaces that can induce a beneficial impact on cell mechanisms, such as adhesion, proliferation, migration and differentiation are of utmost relevance in Tissue engineering (TE) approaches. The surface topography is a captivating property that contribute to interesting cell responses, being inspired by several cues found in nature. Therefore, the study herein presented reports the fabrication of a surface topography using the Rubus fruticosus leaf on spin casting polycaprolactone (PCL) membranes. The topography was replicated by replica molding rapid fabrication technique and nanoimprint lithography (NIL). The biomimetic patterned PCL membranes (bpM) were successfully produced revealing high detail due to the complexity of the leaf's surface ranging from the stroma structures to nerves structures. The thermal evaluation revealed a slight increase of crystallinity of the bpM compared with the other tested conditions. However, did not induce significant effects on the melting and recrystallization temperatures. The mechanical properties revealed that the young modulus increase from 3.2 MPa to 4.4 MPa during the imprinting process. However, bpM presents a lowest elongation capacity than bare membrane (bM) (1076 to 444 %, respectively) due to the heterogeneous thickness induced by the topography. The selected topography revealed to promote a positive bioresponse, depicted by the improvement of the cellular behaviour and different organization. This promising strategy revealed that circumventing the traditional topographies by nature mimetic topographies is fundamental for the development of innovative bioresponsive substrates that can tune cellular behaviour in TE strategies.

IL33 and IL1RL1 variants are associated with asthma and atopy in a Brazilian population.

Atopic asthma is a chronic inflammatory disease in airways resulting from genetic and environmental factors, characterized by production of the Th2 cytokines interleukin-4 (IL-4), interleukin-5 (IL-5) and interleukin-13 (IL-13). Interleukin-33 (IL-33) appears to be a potent inducer of Th2 immune response. This occurs when IL-33 binds and activates its receptor, the membrane ST2 (ST2L) in mast cells, dendritic cells, basophils, eosinophils, innate lymphoids and Th2 cells, leading to the release of these cytokines and intensifying allergic inflammation. Polymorphisms in the IL33 and IL1RL1 can act as protective or risk factors for asthma and/or allergy in humans. No study was conducted to replicate such findings in a European and African descendent mixed population. DNA was extracted from peripheral blood from 1223 subjects, and the samples were genotyped using Illumina 2.5 Human Omni Beadchip. We tested for possible associations between SNPs in the IL33 and ST2 with asthma and allergy markers such as specific IgE (sIgE), IL-5 and IL-13 production and skin prick test (SPT). Logistics regressions were performed using PLINK software 1.07. The analyses were adjusted for sex, age, helminth infection and ancestry markers. The G allele of IL33 SNP rs12551256 was negatively associated with asthma (OR 0.71, 95% CI: 0.53-0.94, P = 0.017). In contrast, the A allele of IL1RL1 rs1041973 was positively associated with IL-5 production (OR 1.36, 95% CI: 1.09-1.84, P = 0.044), sIgE levels (OR 1.40, 95% CI: 1.07-1.84, P = 0.013) and positive SPT (OR 1.48, 95% CI: 1.08-2.03, P = 0.014), for Blomia tropicalis mite. The same allele, in atopic subjects, was associated with decreased production of soluble ST2 (sST2) (P < 0.05). Moreover, expression quantitative trait loci (eQTL) analysis suggests that rs1041973 and rs873022 regulate the expression of IL1RL1 gene. This latest SNP, rs873022, the T allele, was also associated with a lower production of sST2 in plasma of Brazilians. The genetic risk score for rs1041973 and rs16924161 demonstrated a higher risk for SPT positivity against B. tropicalis, the greater the number of risk alleles for both SNPs. Our findings demonstrate a robust association of genetic variants in IL1RL1 and IL33 SNPs with allergy markers and asthma.

In vitro chondrogenic commitment of human Wharton's jelly stem cells by co-culture with human articular chondrocytes.

Wharton's jelly stem cells (WJSCs) are a potential source of transplantable stem cells in cartilage-regenerative strategies, due to their highly proliferative and multilineage differentiation capacity. We hypothesized that a non-direct co-culture system with human articular chondrocytes (hACs) could enhance the potential chondrogenic phenotype of hWJSCs during the expansion phase compared to those expanded in monoculture conditions. Primary hWJSCs were cultured in the bottom of a multiwell plate separated by a porous transwell membrane insert seeded with hACs. No statistically significant differences in hWJSCs duplication number were observed under either of the culture conditions during the expansion phase. hWJSCs under co-culture conditions show upregulations of collagen type I and II, COMP, TGFß1 and aggrecan, as well as of the main cartilage transcription factor, SOX9, when compared to those cultured in the absence of chondrocytes. Chondrogenic differentiation of hWJSCs, previously expanded in co-culture and monoculture conditions, was evaluated for each cellular passage using the micromass culture model. Cells expanded in co-culture showed higher accumulation of glycosaminoglycans (GAGs) compared to cells in monoculture, and immunohistochemistry for localization of collagen type I revealed a strong detection signal when hWJSCs were expanded under monoculture conditions. In contrast, type II collagen was detected when cells were expanded under co-culture conditions, where numerous round-shaped cell clusters were observed. Using a micromass differentiation model, hWJSCs, previously exposed to soluble factors secreted by hACs, were able to express higher levels of chondrogenic genes with deposition of cartilage extracellular matrix components, suggesting their use as an alternative cell source for treating degenerated cartilage. Copyright © 2015 John Wiley & Sons, Ltd.

Bottom-up approach to construct microfabricated multi-layer scaffolds for bone tissue engineering.

The use of bottom-up approaches in tissue engineering applications is advantageous since they enable the combination of various layers that could be made from different materials and/or incorporate different biochemical cues. Regarding the complex structure and the vascular system of the bone tissue, the aim of this study was to develop an innovative bottom-up approach that allows the construction of 3D biodegradable scaffolds from 2D microfabricated membranes with precise shape, pore size and porosity. For that purpose, poly (caprolactone) (PCL) and starch ­ poly (caprolactone) (SPCL (30 % starch)) blended sheets were used as substrates to produce the microfabricated membranes using micro hotembossing. The use of this micro fabrication process allowed accurately imprinting micropillars and microholes in reproducible way. The assembling of the microfabricated membranes was performed using an easy, highly reproducible and inexpensive approach based on its successive stacking. Additionaly, the suitability of the microfabricated membranes to support the attachment and the cytoskeletal organization of human bone marrow stem cells (hBMSCs), macrovascular endothelial cells and osteoblasts derived from hBMSCs was demonstrated. Furthermore, hBMSCs proliferated and maintained the expression of the stromal progenitor marker STRO-1 when cultured on both PCL and SPCL microfabricated membranes. The proposed methodology constitutes a promising alternative to the traditional processing methods used to prepare tissue engineering scaffolds.

Detection of parasite antigens in Leishmania infantum-infected spleen tissue by monoclonal antibody-, piezoelectric-based immunosensors.

Diseases such as leishmaniases are important causes of morbidity and mortality in Brazil, and their diagnoses need to be improved. The use of monoclonal antibodies has ensured high specificity to immunodiagnosis. The development of an immunosensor, coupling a monoclonal antibody to a bioelectronic device capable of quickly detecting Leishmania sp. antigens both qualitatively and quantitatively, is a promising alternative for the diagnosis of leishmaniasis due to its high specificity, low cost, and portability, compared with conventional methods. The present work was aimed at developing an immunosensor-based assay for detecting Leishmania infantum antigens in tissues of infected hosts. Four hybridomas producing monoclonal antibodies against L. infantum had their specificity confirmed by enzyme-linked immunosorbent assay. These antibodies were immobilized on a gold surface, covered with a thin film of 2-aminoethanethiol (cysteamine) and glutaraldehyde, blocked with glycine, and placed into contact with extracts of L. infantum -infected and noninfected control hamster spleens. The assay was able to detect 1.8 × 10(4) amastigotes/g of infected tissue. These results demonstrated that this assay may be useful for quantifying L. infantum amastigotes in organs of experimental animals for studies on pathogenesis and immunity and that it is a promising tool for the development of a diagnostic method, based on antigen detection, of human and dog visceral leishmaniasis.

Unveiling the effects of the secretome of mesenchymal progenitors from the umbilical cord in different neuronal cell populations.

It has been previously shown that the secretome of Human Umbilical Cord Perivascular Cells (HUCPVCs), known for their mesenchymal like stem cell character, is able to increase the metabolic viability and hippocampal neuronal cell densities. However, due to the different micro-environments of the distinct brain regions it is important to study if neurons isolated from different areas have similar, or opposite, reactions when in the presence of HUCPVCs secretome (in the form of conditioned media-CM). In this work we: 1) studied how cortical and cerebellar neuronal primary cultures behaved when incubated with HUCPVCs CM and 2) characterized the differences between CM collected at two different conditioning time points. Primary cultures of cerebellar and cortical neurons were incubated with HUCPVCs CM (obtained 24 and 96 h after three days of culturing). HUCPVCs CM had a higher impact on the metabolic viability and proliferation of cortical cultures, than the cerebellar ones. Regarding neuronal cell densities it was observed that with 24 h CM condition there were higher number MAP-2 positive cells, a marker for fully differentiated neurons; this was, once again, more evident in cortical cultures. In an attempt to characterize the differences between the two conditioning time points a proteomics approach was followed, based on 2D Gel analysis followed by the identification of selected spots by tandem mass spectrometry. Results revealed important differences in proteins that have been previously related with phenomena such as neurl cell viability, proliferation and differentiation, namely 14-3-3, UCHL1, hsp70 and peroxiredoxin-6. In summary, we demonstrated differences on how neurons isolated from different brain regions react to HUCPVCs secretome and we have identified different proteins (14-3-3 and hsp70) in HUCPVCs CM that may explain the above-referred results.

A proteomic approach to identify proteins from Trichuris trichiura extract with immunomodulatory effects.

Infections with Trichuris trichiura and other trichurid nematodes have been reported to display protective effects against atopy, allergic and autoimmune diseases. The aims of the present study were to investigate the immunomodulatory properties of T. trichiura adult worm extract (TtE) and its fractions (TtEFs) on the production of cytokines by peripheral blood mononuclear cells and to identify their proteinaceous components. Fourteen TtEFs were obtained by ion exchange chromatography and tested for effects on cytokine production by peripheral blood mononuclear cells. The molecular constituents of the six most active fractions were evaluated using nano-LC/mass spectrometry. The homology between T. trichiura and the related nematode Trichinella spiralis was used to identify 12 proteins in TtEFs. Among those identified, fructose biphosphate aldolase, a homologue of macrophage migration inhibitory factor and heat-shock protein 70 may contribute to the immunomodulatory effects of TtEFs. The identification of such proteins could lead to the development of novel drugs for the therapy of allergic and other inflammatory diseases.

Osteogenic differentiation of two distinct subpopulations of human adipose-derived stem cells: an in vitro and in vivo study.

The first stem cells considered for the reconstruction of bone were bone marrow mesenchymal stem cells (BMSCs). Subsequently, cells with similar marker expression panel and differentiation potential were found in new sources of cells, such as adipose tissue. This source of stem cells has a promising future in tissue-engineering applications, considering the abundance of this tissue in the human body, the easy harvesting and the high number of stem cells that are available from such a small amount of tissue. The isolation of the adipose stem cells is generally performed by means of enzymatic digestion of the tissues, followed by a natural selection of the stem cells based on their capacity to adhere to the culture flasks, leading to a quite heterogeneous population. This constitutes a major drawback for the use of these cells, since the heterogeneity of the cell culture obtained can compromise their proliferation and differentiation potential. In the present study we have analysed the in vitro and in vivo behaviour of two selected subpopulations with high osteogenic potential. For this purpose, ASCs(CD29+) and ASCs (STRO-1+)subpopulations were isolated and in vitro cultured onto a biodegradable polymeric scaffold, using osteogenic medium, before implantation in a nude mice model. The biodegradable polymeric scaffold used is a fibre-mesh structure based on a blend of starch and polycaprolatone (SPCL) that has been successfully used in several bone tissue-engineering studies. The implanted ASCs-scaffold constructs promoted the formation of new bone tissue in nude mice. However, the results obtained show differences in the behaviour of the two ASCs subpopulations under study, particularly regarding their potential to differentiate into the osteogenic lineage, and allowed the indentification of ASCs (STRO-1+) as the best subpopulation for bone tissue-engineering applications.

Chitosan-poly(butylene succinate) scaffolds and human bone marrow stromal cells induce bone repair in a mouse calvaria model.

Tissue engineering sustains the need of a three-dimensional (3D) scaffold to promote the regeneration of tissues in volume. Usually, scaffolds are seeded with an adequate cell population, allowing their growth and maturation upon implantation in vivo. Previous studies obtained by our group evidenced significant growth patterns and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) when seeded and cultured on melt-based porous chitosan fibre mesh scaffolds (cell constructs). Therefore, it is crucial to test the in vivo performance of these in vitro 3D cell constructs. In this study, chitosan-based scaffolds were seeded and cultured in vitro with hBMSCs for 3 weeks under osteogenic stimulation conditions and analysed for cell adhesion, proliferation and differentiation. Implantation of 2 weeks precultured cell constructs in osteogenic culture conditions was performed into critical cranial size defects in nude mice. The objective of this study was to verify the scaffold integration and new bone formation. At 8 weeks of implantation, scaffolds were harvested and prepared for micro-computed tomography (µCT) analysis. Retrieved implants showed good integration with the surrounding tissue and significant bone formation, more evident for the scaffolds cultured and implanted with human cells. The results of this work demonstrated that chitosan-based scaffolds, besides supporting in vitro proliferation and osteogenic differentiation of hBMSCs, induced bone formation in vivo. Thus, their osteogenic potential in orthotopic location in immunodeficient mice was validated, evidencing good prospects for their use in bone tissue-engineering therapies.

Chondrogenic differentiation of human bone marrow mesenchymal stem cells in chitosan-based scaffolds using a flow-perfusion bioreactor.

Native articular cartilage is subjected to synovial fluid flow during normal joint function. Thus, it is believed that the morphogenesis of articular cartilage may be positively regulated by the application of similar stimulation in vitro. In the present study, the effect of fluid flow over the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) was investigated. We intended to find out whether the shear stress caused by perfusion of the medium through the constructs was capable of augmenting the differentiation process. Human BMSCs were isolated from bone marrow aspirates and were characterized by flow cytometry. After expansion, hBM-MSCs were seeded statically onto fibre mesh scaffolds, consisting of a blend of 50:50 chitosan:poly(butylene terephthalate adipate) (CPBTA). Constructs were cultured in a flow-perfusion bioreactor for 28 days, using complete medium for chondrogenesis supplemented by TGFß3. An enhanced ECM deposition and collagen type II production was observed in the bioreactor samples when compared to the static controls. Moreover, it was observed that hBM-MSCs, in static cultures, take longer to differentiate. ECM accumulation in these samples is lower than in the bioreactor sections, and there is a significant difference in the expression of collagen type I. We found that the flow-induced shear stress has a beneficial effect on the chondrogenic differentiation of hMSCs.

Oocyst ingestion as an important transmission route of Toxoplasma gondii in Brazilian urban children.

Toxoplasmosis is a cosmopolitan protozoan infection. Data regarding risk factors for the post-natal acquisition of Toxoplasma gondii infection in childhood are limited. We conducted a serological survey for T. gondii IgG antibodies and associated risk factors in 1,217 children 4-11-yr-old from Salvador, Brazil, using a commercial ELISA kit; antibodies were found in 17.5% of the children. Age (OR  =  2.18; 95% CI: 1.50-3.17) and maternal schooling level (OR  =  0.62; 95% CI: 0.42-0.92) were negatively associated with infection. A greater number of siblings (OR  =  1.53; 95% CI: 1.12-2.09), cat at home (OR  =  1.54; 95% CI: 1.06-2.24), house with non-treated piped water (OR  =  2.54; 95% CI: 1.22-5.31), and the absence of a flush toilet at home (OR  =  1.45; 95% CI: 1.04-2.01) were positively associated with T. gondii infection. Our data suggest that low socioeconomic levels and poor hygiene habits are important factors in favoring T. gondii infection.

Toxocara canis infection is associated with eosinophilia and total IgE in blood donors from a large Brazilian centre.

OBJECTIVE: To investigate the association between Toxocara canis infection and total IgE levels and eosinophilia in blood donors from a large Brazilian city. METHODS: Two hundred and sixty-eight blood donors from a government blood bank were tested. No helminth infection was diagnosed by parasitological stool examination. Total IgE levels and T. canis infection status were determined by ELISA. Eosinophil levels were determined using an automatic blood cell counter. RESULTS: Toxocara canis IgG antibodies were found in 124 (46.3%); 102 (38.0%) had eosinophilia ≥4% and 29 (10.8%) had eosinophilia ≥10%, respectively; 140 (52.2%) individuals had total IgE antibodies above the cut-off levels. Both total IgE and eosinophil levels ≥10% were positively associated with the infection. CONCLUSION: This study revealed a high prevalence of T. canis infection in blood donors, highlighting the need for screening for this infection. It also demonstrated that this population otherwise healthy has higher levels of blood eosinophils and total IgE and that both parameters are associated with T. canis infection.

Cartilage tissue engineering using electrospun PCL nanofiber meshes and MSCs.

Mesenchymal stem cells (MSCs) have been recognized for their ability to differentiate into cells of different tissues such as bone, cartilage, or adipose tissue, and therefore are of great interest for potential therapeutic strategies. Adherent, colony-forming, fibroblastic cells were isolated from human bone marrow aspirates, from patients undergoing knee arthroplasties, and the MSCs phenotype characterized by flow cytometry. Afterward, cells were seeded onto electrospun polycaprolactone nanofiber meshes and cultured in a multichamber flow perfusion bioreactor to determine their ability to produce cartilagineous extracellular matrix. Results indicate that the flow perfusion bioreactor increased the chondrogenic differentiation of hBM-MSCs, as confirmed either by morphological and RT-PCR analysis. Cartilage-related genes such as aggrecan, collagen type II, and Sox9 were expressed. ECM deposition was also detected by histological procedures. Collagen type II was present in the samples, as well as collagen type I. Despite no statistically significant values being obtained for gene expression, the other results support the choice of the bioreactor for this type of culture.