A biologic-device combination product delivering tumor-derived antigens elicits immunogenic cell death-associated immune responses against glioblastoma.

BACKGROUND: IGV-001 is a personalized, autologous cancer cell-based immunotherapy conceived to deliver a tumor-derived antigenic payload in the context of immunostimulatory signals to patients with glioblastoma (GBM). IGV-001 consists of patient-derived GBM cells treated with an antisense oligodeoxynucleotide against insulin-like growth factor 1 receptor (IGF1R) and placed in proprietary biodiffusion chambers (BDCs). The BDCs are then exposed to 5-6 Gy radiation and implanted at abdominal sites for ~48 hours. IGV-001 has previously been shown to be generally safe with promising clinical activity in newly diagnosed GBM patients. METHODS: Mouse (m) or human (h) variants of IGV-001 were prepared using GL261 mouse GBM cells or human GBM cells, respectively. BDCs containing vehicle or mIGV-001 were implanted in the flanks of C57BL/6 albino female mice in preventative and therapeutic experiments, optionally in combination with a programmed cell death 1 (PD-1) blocker. Bioactivity of the general approach was also measured against hepatocellular carcinoma Hepa 1-6 cells. Mice were followed for the growth of subsequently implanted or pre-existing tumors and survival. Draining lymph nodes from mice receiving mIGV-001 were immunophenotyped. mIGV-001 and hIGV-001 were analyzed for extracellular ATP and high mobility group box 1 (HMGB1) as indicators of immunogenic cell death (ICD), along with flow cytometric analysis of viability, surface calreticulin, and reactive oxygen species. Stress and cell death-related pathways were analyzed by immunoblotting. RESULTS: IGV-001 causes oxidative and endoplasmic reticulum stress in GL261 cells, resulting in a cytotoxic response that enables the release of antigenic material and immunostimulatory, ICD-associated molecules including ATP and HMGB1 from BDCs. Immunophenotyping confirmed that IGV-001 increases the percentage of dendritic cells, as well as effector, and effector memory T cells in BDC-draining lymph nodes. Consistent with these observations, preventative IGV-001 limited tumor progression and extended overall survival in mice intracranially challenged with GL261 cells, a benefit that was associated with an increase in tumor-specific T cells with effector features. Similar findings were obtained in the Hepa 1-6 model. Moreover, therapeutically administered IGV-001 combined with PD-1 delayed progression in GBM-bearing mice. CONCLUSIONS: These results support treatment with IGV-001 to induce clinically relevant ICD-driven anticancer immune responses in patients with GBM.

Natural killer cells activity against multiple myeloma cells is modulated by osteoblast-induced IL-6 and IL-10 production.

Background: Natural killer (NK) cells are part of the innate arm of the immune system; as such NK cells can be activated rapidly to target virus-infected cells and tumor cells without prior sensitization. The human NK-92MI cell line is among the most widely used NK cell in preclinical research studies and has also been approved for clinical applications. Previous studies have shown that osteoblasts (OSB) confer drug resistance in multiple myeloma (MM) and other cancers that metastasize to the bone marrow. Aim: We evaluated here how OSB, which are bone forming cells and a key cellular component of the bone marrow microenvironment, modulate the cytotoxic activity of NK-92MI cells against the MM.1S multiple myeloma cell line. Methods: The osteoblastic niche was recapitulated with either the osteoblastic cell line hFOB 1.19 (hFOB) or primary osteoblasts (P-OSB) derived from surgical resections. Time-lapse imaging was utilized to quantify changes in MM.1S cell viability under different conditions, including: (1) Co-culture of MM.1S with NK92MI cells, (2) triple-culture of hFOB or P-OSB with MM.1S and NK-92MI, and (3) MM.1S or NK-92MI cells primed with OSB-derived supernatant. Cytokine analysis was conducted to quantify potential secreted factors associated with the protective effects of OSB. Results: The physical presence of OSB hindered the activity of NK-92MI cells, resulting in the increased viability of MM.1S compared to co-cultures which lacked OSB. This observation was accompanied by reduced perforin and granzyme A secretion from NK-92MI cells. Contact of OSB and NK-92MI cells also induced interleukin 6 (IL-6) and interleukin 10 (IL-10) production; two cytokines which are known to impair the NK cell immunity against MM and other cancers. OSB supernatant also conferred cytoprotection to MM.1S, suggesting a dual mechanism by which OSB may modulate both NK and MM cells. Conclusions: We demonstrated here that OSB can negatively impact the activity of NK cells against MM. As NK cells and their chimeric antigen receptor-modified versions become more widely used in the clinic, our results suggest that understanding the role of OSB as potential immunoregulators of the NK cell-mediated cytotoxic response in the bone marrow tumor microenvironment may provide new opportunities for enhancing the effectiveness of this potent immunotherapeutic approach.

Bi-layer blood vessel mimicking microfluidic platform for antitumor drug screening based on co-culturing 3D tumor spheroids and endothelial layers.

Two-dimensional (2D) cell culture is not ideal for traditional drug screening, because 2D culture does not accurately mimic the physiological microenvironment of tumor cells. Thus, a drug-screening system which more closely mimics the microenvironment of in vivo tumors is necessary. Here, we present a biomimicking bilayer microfluidic device that can facilitate antitumor drug screening. The microfluidic device consists of two polydimethylsiloxane (PDMS) pieces with channels which are separated by a semipermeable membrane to allow water, oxygen, and nutrition supply, while preventing cell migration. The channels embedded on the two PDMS pieces overlap each other over a long distance to ensure a larger exchange area to mimic the blood vessel-tumor model. High concentrations of endothelial cells (EC) are first seeded onto the membrane through the apical channel, and after a two-day culture, a confluent EC monolayer forms. Tumor spheroid-laden Matrigel is then seeded into the basal channel. After the Matrigel is cured, the device is ready for drug testing. Paclitaxel is used as the model drug for testing. Confocal microscopy and ImageJ are used to assess the efficacy of different concentrations of paclitaxel, and optical coherence tomography (OCT) is employed to determine the tumor volumetric change after the drug treatment. The results indicate that the proposed bilayer microfluidic device in combination with confocal and OCT optical characterization provide an efficient platform for antitumor drug testing.

120 GBd plasmonic Mach-Zehnder modulator with a novel differential electrode design operated at a peak-to-peak drive voltage of 178 mV.

A new plasmonic Mach-Zehnder modulator is demonstrated at a bit rate of 120 Gb/s NRZ-OOK with low peak-to-peak driving voltages of 178 mVpp below the HD-FEC limit. Such record low driving voltage requirements potentially translate into an electrical drive power consumption of 862 aJ/bit. The low drive voltages have been made possible by a new differential Mach-Zehnder modulator electrode design. The differential electrode design is optimized for the balanced driving circuitry and reduces the effectively required driving voltage by a factor of four (Vπ/4). The potential of the transmitter scheme is further demonstrated by a transmission experiment over 500 m of single mode fiber at the C-band with a BER performance below the KP4 FEC limit.

Microfluidic device for expedited tumor growth towards drug evaluation.

Patient derived organoids have emerged as robust preclinical models for screening anti-cancer therapeutics. Current 2D culturing methods do not provide physiological responses to therapeutics, therefore 3D models are being developed to better reproduce physiological responses. 3D culturing however often requires large initial cell populations and one week to one month to grow tumors ready for therapeutic testing. As a solution a 3D culturing system has been developed capable of producing physiologically relevant tumors in an expedited fashion while only requiring a small number of initial cancer cells. A bi-layer microfluidic system capable of facilitating active convective nutrient supply to populations of cancer cells facilitates expedited growth of cancer cells when starting with populations as small as 8 cells. The system has been shown to function well with adherent and non-adherent cell types by expediting cell growth by a factor ranging from 1.27 to 4.76 greater than growth under static conditions. Utilizing such an approach has enable to formation of tumors ready for therapeutic screening within 3 days and the ability to perform therapeutic screening within the microfluidic system is demonstrated. A mathematical model has been developed which allows for adjustments to be made to the dynamic delivery of nutrients in order to efficiently use culture media without excessive waste. We believe this work to be the first attempt to grow cancers in an expedited fashion utilizing only a convective nutrient supply within a microfluidic system which also facilitates on-device therapeutic screening. The developed microfluidic system and cancer growth method have the potential to offer improved drug screening for patients in clinical settings.

Facile Tumor Spheroids Formation in Large Quantity with Controllable Size and High Uniformity.

A facile method for generation of tumor spheroids in large quantity with controllable size and high uniformity is presented. HCT-116 cells are used as a model cell line. Individual tumor cells are sparsely seeded onto petri-dishes. After a few days of growth, separated cellular islets are formed and then detached by dispase while maintaining their sheet shape. These detached cell sheets are transferred to dispase-doped media under orbital shaking conditions. Assisted by the shear flow under shaking and inhibition of cell-to-extracellular matrix junctions by dispase, the cell sheets curl up and eventually tumor spheroids are formed. The average size of the spheroids can be controlled by tuning the cell sheet culturing period and spheroid shaking period. The uniformity can be controlled by a set of sieves which were home-made using stainless steel meshes. Since this method is based on simple petri-dish cell culturing and shaking, it is rather facile for forming tumor spheroids with no theoretical quantity limit. This method has been used to form HeLa, A431 and U87 MG tumor spheroids and application of the formed tumor spheroids in drug screening is also demonstrated. The viability, 3D structure, and necrosis of the spheroids are characterized.

Biomimetic microfluidic platform for the quantification of transient endothelial monolayer permeability and therapeutic transport under mimicked cancerous conditions.

Therapeutic delivery from microvasculature to cancerous sites is influenced by many factors including endothelial permeability, vascular flow rates/pressures, cancer secretion of cytokines and permeabilizing agents, and characteristics of the chosen therapeutics. This work uses bi-layer microfluidics capable of studying dye and therapeutic transport from a simulated vessel to a cancerous region while allowing for direct visualization and quantification of endothelial permeability. 2.5 to 13 times greater dye transport was observed when utilizing small dye sizes (FITC) when compared to larger molecules (FITC-Dextran 4 kDa and FITC-Dextran 70 kDa), respectively. The use of lower flow rates/pressures is shown to improve dye transport by factors ranging from 2.5 to 5 times, which result from increased dye diffusion times within the system. Furthermore, subjecting confluent endothelial monolayers to cancerous cells resulted in increased levels of vascular permeability. Situations of cancer induced increases in vascular permeability are shown to facilitate enhanced dye transport when compared to non-diseased endothelial monolayers. Subsequent introduction of paclitaxel or doxorubicin into the system was shown to kill cancerous cells resulting in the recovery of endothelial confluency overtime. The response of endothelial cells to paclitaxel and doxorubicin is quantified to understand the direct influence of anti-cancer therapeutics on endothelial growth and permeability. Introduction of therapeutics into the system showed the recovery of endothelial confluency and dye transport back to conditions experienced prior to cancer cell introduction after 120 h of continuous treatment. Overall, the system has been utilized to show that therapeutic transport to cancerous sites depends on the size of the chosen therapeutic, the flow rate/pressure established within the vasculature, and the degree of cancer induced endothelial permeability. In addition, treatment of the cancerous region has been demonstrated with anti-cancer therapeutics, which are shown to influence vascular permeability in direct (therapeutics themselves) and indirect (death of cancer cells) manners. Lastly, the system presented in this work is believed to function as a versatile testing platform for future anti-cancer therapeutic testing and development.

Magnetic particles assisted capture and release of rare circulating tumor cells using wavy-herringbone structured microfluidic devices.

A wavy-herringbone (wavy-HB) structured microfluidic device was used to effectively and selectively capture and release circulating tumor cells (CTCs) by using immunoaffinity and magnetic force. This device was designed to create passive turbulence and increase the possibility of tumor cells colliding with the device wall. Under an external magnetic field, magnetic particles (MPs) coated with anti-EpCAM against a tumor cell surface protein (EpCAM) were immobilized over the wavy-HB surface to capture tumor cells. After removing the magnetic field, the captured cells with surplus MPs were released from the device and collected; thus, these cells could be re-cultured for further analysis. Under optimized conditions, the capture efficiency of the tumor cells can be as high as 92% ± 2.8%. Capture experiments were also performed on whole blood samples, and the capture efficiency was in a high range of 81-95%, at different tumor cell concentrations. Such a method can potentially be used for CTC sorting from patient blood samples, CTC concentration monitoring, therapeutic guidance and drug dosage choice, and further study of tumors, such as drug screening and tumor mutations.

Mechanical response of cardiovascular stents under vascular dynamic bending.

BACKROUND: Currently, the effect of vascular dynamic bending (VDB) has not been fully considered when studying cardiovascular stents' long-term mechanical properties, as the previous studies about stent's mechanical properties mostly focus on the effect of vascular pulsation (VP). More and more clinical reports suggested that the effect of VDB have a significant impact on stent. METHODS: In this paper, an explicit-implicit coupling simulation method was applied to analyze the mechanical responses of cardiovascular stents considering the effect of VDB. The effect of VP on stent mechanical properties was also studied and compared to the effect of VDB. RESULTS: The results showed that the dynamic bending deformation occurred in stents due to the effect of VDB. The effects of VDB and VP resulted in alternating stress states of the stent, while the VDB alternate stresses effective on the stent were almost three times larger than that of the VP. The stress concentration under VDB mainly occurred in bridge struts and the maximal stress was located in the middle loops of the stent. However, the stress distributed uniformly in the stents under the effect of VP. Stent fracture occurred more frequently as a result of VDB with the predicted fracture position located in the bridging struts of the stent. These results are consistent with the reported data in clinical literatures. The stress of the vessel under VDB was higher, than that caused by VP. CONCLUSIONS: The results showed that the effect of VDB has a significant impact on the stent's stress distribution, fatigue performance and overall stress on the vessel, thus it is necessary to be considered when analyzing stent's long-term mechanical properties. Meanwhile, the results showed that the explicit-implicit coupling simulation can be applied to analyze stent mechanical properties.

O Pará no século XXI: oportunidades para o desenvolvimento sustentável / The State of Pará in twenty-first century: opportunities to sustainable development

Aborda questões críticas e emergentes sobre o uso da terra no Pará. Avalia a capacidade das instituições regionais em identificar e tratar essas questões. Analisa sete das principais formas de uso dos recursos naturais. Identifica necessidades que devem ser abordadas para apoiar cada uma dessas formas. Identifica áreas prioritárias para o trabalho futuro das instituições regionais do Pará. Analisa vinte e três instituições regionais, incluindo órgãos públicos e ONGs. Verifica que muitas das agências governamentais sofrem de falta de clareza em sua missão e de formas não-participativas de administração. Em contrapartida, muitas ONGs possuem uma missão bem definida e uma equipe profundamente motivada, porém atuam dentro de uma escala extremamente limitada. Explora as formas pelas quais as agências governamentais podem se tornar muito mais eficientes na definição e realização de suas missões e diminuir o impacto trágico do desmatamento na Amazônia Oriental.

Land-use in Amazonia and the cerrado of Brazil

The total area and annual rate of native vegetation clearing is greatest in the Cerrado region followed by the Brazilian states of Par , Mato Grosso, Maranhao and Rond"nia. Amazonian forest clearing proceeds most quickly where abundant natural resources (wood or land) are accessible by roads and close to markets. These regions are concentrated along the eastern and southern flanks of Amazonia, particularly in eastern Par , Cuiab and Rond"nia. There are still large discrepancies in estimates of annual deforestation; Landsat (Thematic Mapper-based) mapping of deforestation in the closed-canopy forests of Amazonia has not include non-Brazilian countries and is incomplete for the cerrado biome. Amazonian deforestation was last mapped in 1994. Current estimates of Amazonian forest clearing do not include most of the forests that are effected by logging each year, which is an area (about 7,000 Km2yr-1) more than half the size of the area of annual deforestation. Logging changes forest structure and increases forest flammability. The intensity of logging ranges from 1- to 100-species harvest, and averages 20 m3 of wood harvested per hectare. Logging may increase dramatically in the coming years. Fire affects large, but difficult to measure, areas of pastureland, logged forests, secondary forests and primary forests. Forest ground fires are particularly difficult to map from satellite data. Fire is more frequent where forest clearing is taking place, and where seasonal drough is most severe. The destiny of Amazonian forest land cleared for crops and cattle pasture is complex, and highly variable regionally. Areal estimates are needed for managed pasture, degraded pasture, cropland and secondary forests, for these ecosystems are functionally distinct. Most forest clearing is for pasture establishment, followed by shifting cultivation. Cattle pasture is the logical land-use for both small-scale and large-scale rural Amazonians because cattle are easily sold or traded, and they maintain their value during inflation. Cattle pastures help secure land claims and increase land value. In the Cerrado, there has been a shift from extesive cattle grazing of natural savannas to pastures planted with African forage grasses; mechanized soy bean production is the second most extensive land-use. Pastures are the most important land-cover for the LBA (Large-Scale Biosphere-Atmosphere experiment in Amazonia) science campaign. Brazilian Amazonia experiences reduced rainfall...

Transpiration rates for several woody successional species and for a pasture in the upper Amazon basin in Venezuela

Evapotranspiration rates for a eight month old tropical pasture were estimated using the Penman-Monteith equation. Transpiration rates for several woody secondary successional species and stump sprous in the pasture and conucos (farm sites) were measured using the tritiated water technique.The stuty area was located near the village of San Carlos de Rio Negro (1° 56' N, 67° 03' W) in southern Venezuela, near the confluence of the Casiquiare and the Rio Guania wich forms the Rio Negro. The terrain was gently rolling with the areas between the small ridges supporting Amazon caatina forests on spodosols, and higher never flooded areas (tierra firma) supporting a mixed species forest.Results indicated that for a one month period, ET loss (0.46 cm/day) from the pasture, including soil and root mat evaporation, was about 0.43 cm/day less than estimated from the adjacent undisturbed forest (0.89 cm/day). Pan A evaporation for the same time period was 0.64 cm/day. Transpiration rates for seed established species were significantly less (0.38 cm/day) than for stump sprouts (1.09 cm/day) of the primary forest in the pasture.

As taxas de evapotranspiração de uma pastagem de oito meses foram estimadas usando a equação Penman-Monteith. As taxas de transpiração de várias espécies lenhosas sucessionais e rebrotos na pastagem e canucos (fazendas) foram medidas com o uso de água radiada com tritio. O local de estudo estava localizado perto do vilarejo de São Casrlos do Rio Negro (1° 56' N, 67° 03' W) na parte sul da Venezuela, próximo a confluência do Casiquiare e Rio Gania, que formam o Rio Negro. O terreno era levemente ondulado com as áreas entre os pequenos cumes que sustentam uma mata de espécies mistas. Os resultados mostraram que durante o período de um mês, a perda de ET (0.46 cm/dia) da pastagem, incluindo a evaporação do solo e da camada das raízes, foi de cerca de 0.43 cm/dia menos que a estimada para a mata adjacente não-perturbada (0.89 cm/dia). A evaporação Pan A para o mesmo período foi de 0.64 cm/dia. As taxas de transpiração para as espécies estabelecidas através de sementes foram significativamente menores (0.38 cm/dia) do que para os rebrotos (1.09 cm/dia) das espécies da mata primária na pastagem.