Commercial Suppliers Research Articles

Discontinuous alkylation of diphenylamine with nonene for maximum catalyst utilization

This study examines the alkylation of diphenylamine (DPA) with nonene (NON) in a liquid phase catalyzed by acid-treated clay-based catalysts from commercial suppliers (Fulcat 22B, Nobelin MM, and Jeltar 300). Alkylations were conducted to achieve the highest possible selectivity of diisononyldiphenylamine (DNDPA), low selectivity of monoisononyldiphenylamine, and a maximum triisononyldiphenylamine yield of 4%. This study also examines the reaction conditions to selectively form dialkylated diphenylamine from DPA and NON in a batch reactor. Repeated use of the catalyst during the alkylation of DPA with NON was also investigated. Catalyst deactivation takes place during the alkylation of each batch and intensifies with repeated catalyst use, resulting in low DNDPA selectivity. The regenerated catalyst was sufficiently active only until the regeneration of the first and second batches. After the third batch, the catalyst’s selectivity for DNDPA was very low, and its reuse in the alkylation of DPA with NON was not efficient. Therefore, to achieve the maximum length of catalyst activity, the fresh catalyst was gradually added to the used catalyst from a previous batch, thus maintaining a high activity of eight batches. The reduction in catalyst activity was probably caused by the irreversible adsorption of substances on the surface, a loss of microporous structure, and a loss of surface acidity. DPA or alkylated products are adsorbed on the surface oxygen of the catalyst through nitrogen and form nitro formations. The fresh and regenerated catalysts were characterized by their surface area, surface acidity, pore size distribution, and pore volume.

Identification of potential glutaminyl cyclase inhibitors from lead-like libraries by in silico and in vitro fragment-based screening.

A glutaminyl cyclase (QC) fragment library was in silico selected by disconnection of the structure of known QC inhibitors and by lead-like 2D virtual screening of the same set. The resulting fragment library (204 compounds) was acquired from commercial suppliers and pre-screened by differential scanning fluorimetry followed by functional in vitro assays. In this way, 10 fragment hits were identified ([Formula: see text]5% hit rate, best inhibitory activity: 16 [Formula: see text]). The in vitro hits were then docked to the active site of QC, and the best scoring compounds were analyzed for binding interactions. Two fragments bound to different regions in a complementary manner, and thus, linking those fragments offered a rational strategy to generate novel QC inhibitors. Based on the structure of the virtual linked fragment, a 77-membered QC target focused library was selected from vendor databases and docked to the active site of QC. A PubChem search confirmed that the best scoring analogues are novel, potential QC inhibitors.

The importance of transport property studies for battery electrolytes: revisiting the transport properties of lithium-N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide mixtures.

Transport properties are examined in some detail for samples of the low temperature molten salt N-propyl-N-methyl pyrrolidinium bis(fluorosulfonyl)imide [Pyr13][FSI] from two different commercial suppliers. A similar set of data is presented for two different concentrations of binary lithium-[Pyr13][FSI] salt mixtures from one supplier. A new and significantly different production process is used for the synthesis of Li[FSI] as well as the [Pyr13]+ salt used in the mixtures. Results for the viscosity, conductivity, and self-diffusion coefficients, together with the density and expansivity and apparent molar volume, are reported over the temperature range of (0 to 80) °C. The data for neat [Pyr13][FSI] are discussed in the context of velocity cross correlation (VCC or fij) and Laity resistance (rij) coefficients. Unusually, f+- ∼ f++ < f--. The three resistance coefficients are of similar magnitude indicating all three ion-ion interactions contribute to the transport properties, not just the cation-anion interaction. The composition dependence of the transport properties is compared to previously reported data for the same and related compounds: in contrast to high-temperature molten salt mixtures, this is an exponential dependence. The Nernst-Einstein parameter Δ, which contains information on the correlations of the ionic velocities and is determined by differences in the VCC for the various ion-ion combinations, was calculated for both the neat ionic liquid and its binary mixture. It increases with increasing lithium concentration. The new data set also allows some conclusions with regards to the lithium-[FSI]- coordination environment.

3D Product Development for Loose-Fitting Garments Based on Parametric Human Models

Researchers and commercial suppliers worldwide pursue the objective of achieving a more transparent garment construction process that is computationally linked to a virtual body, in order to save development costs over the long term. The current aim is not to transfer the complete pattern making step to a 3D design environment but to work out basic constructions in 3D that provide excellent fit due to their accurate construction and morphological pattern grading (automatic change of sizes in 3D) in respect of sizes and body types. After a computer-aided derivation of 2D pattern parts, these can be made available to the industry as a basis on which to create more fashionable variations.

Current methods to manufacture human platelet lysates for cell therapy and tissue engineering: possible trends in product safety and standardization

Human platelet lysates (HPLs), obtained from therapeutic‐grade platelet concentrates (PC), are rich in growth factors and other bioactive molecules. HPL is increasingly evaluated as a substitute for foetal bovine serum (FBS), to likely become the next ‘gold standard’ supplement of growth media for clinical‐grade ex vivo propagation of human cells. HPL avoids the risks of immunological reactions against xenoproteins. HPL quality and safety benefit from the pathogen safety measures in place for producing PC for transfusion. Numerous studies support that HPL‐expanded mesenchymal stromal cells show improved proliferation and decreased doubling time than when using FBS‐supplemented media and maintain characteristic immunophenotype, differentiation capacity and T‐cell immunosuppressive effect. Several methods are used to prepare HPL; they differ in the selection and formulation of the starting PC, the consideration or not for blood groups, the pool size, the membrane lysis procedure, the depletion of fibrinogen, and the implementation or not of a pathogen inactivation step on PC materials or during manufacture. Allogeneic ‘off‐the‐shelf’ pooled HPLs, made from approximately fifty, or more, PC, are currently produced by blood establishments and/or available through commercial suppliers. Improved HPL standardization and safety profile, through larger pools and dedicated viral inactivation and removal treatments, is expected in the next few years, broadening applications in cell therapy and regenerative medicine. Systematic studies of the impact of the mode of production of HPL on the isolation and expansion of various human cell types should be encouraged.

Localized Wood Surface Modification, Part I: Method Characterization

This study assesses the potential of an open process for treatment of European Scots pine (Pinus sylvestris) with chemicals that could potentially make the surfaces stronger, more dimensionally stable, or more durable, depending on the treatment solution. The method provides an intermediate solution between full volume impregnation by pressure treatment and superficial surface treatment by dipping. Figuratively speaking, the process creates the equivalent of a layer of coating applied below the wood surfaces rather than above. Two different techniques were compared, namely, heating-and-cooling (H&C) and compression-and-expansion (C&E). Taking into account that commercial suppliers recommend 0.15 to 0.25 L/m2 of coating in sawn wood and 0.1 to 0.15 L/m2 in planed wood surfaces, then this study demonstrates that the H&C method can impregnate an equivalent amount of solution under the surfaces in less than 15 min using treatment temperatures below 150 °C.

Oxygen storage dominated three-way catalyst modeling for fresh catalysts

Meeting future legislations for the emissions of spark-ignition engines requires the development of efficient three-way catalyst (TWC) models. These models can both be employed for online catalyst control as well as model-based development of control and on-board diagnosis (OBD) strategies. In this paper we present such a model that aims at capturing transient TWC dynamics of fresh catalysts at elevated temperatures. Applying a parameter subset selection strategy, we demonstrate that solely taking into account the dynamics of oxygen storage and release is sufficient for this purpose and reactions associated with processes taking place on the platinum-group metals do not have to be modeled explicitly. The one-dimensional single channel model lumps the exhaust gas species into two pseudo components, one being able to oxidize and one being able to reduce the oxygen storage material. The respective reaction kinetics are considered reversible with non-linear functions depending on the oxidation state of the material being put in the center of focus. Model validation is carried out using experimental data from an isothermal synthetic gas test bench. The applied feed gas composition closely resembles real exhaust conditions under dynamic operation. By employing local parameter sensitivity and identifiability analysis and investigating the differences between a total of five fresh catalysts from different commercial suppliers, we propose a set of only five parameters that can be used to accurately model oxygen storage and release dynamics under isothermal conditions. The results emphasize the importance of accounting for oxygen storage from water as well as the need of using a spatially distributed model. Apart from the above mentioned applications, the model is shown to be suitable for fast catalyst screening and characterization.

Using sea urchin gametes and zygotes to investigate centrosome duplication.

Centriole structure and function in the sea urchin zygote parallel those in mammalian somatic cells. Here, I briefly introduce the properties and attributes of the sea urchin system that make it an attractive platform for the study of centrosome and centriole duplication. These attributes apply to all echinoderms readily available from commercial suppliers: sea urchins, sand dollars, and starfish. I list some of the practical aspects of the system that make it a cost- and time-effective system for experimental work and then list properties that are a “tool kit” that can be used to conduct studies that would not be practical, or in some cases not possible, with mammalian somatic cells. Since centrioles organize and localize the pericentriolar material that nucleates the astral arrays of microtubules (Bobinnec et al. in J Cell Biol 143(6):1575–1589, 1998), the pattern of aster duplication over several cell cycles can be used as a reliable measure for centriole duplication (Sluder and Rieder in J Cell Biol 100(3):887–896, 1985). Descriptions of the methods my laboratory has used to handle and image echinoderm zygotes are reviewed in Sluder et al. (Methods Cell Biol 61:439–472, 1999). Also included is a bibliography of papers that describe additional methods.

AYURVEDIC FORMULATION “NISAMALAKI CHURNA”: A MONOGRAPH

“Nisamalaki churna” is one of the easily available Ayurvedic formulations sold as an OTC drug, used against diabetes mellitus as a home remedy. It is a powdered preparation made from fruit of Emblica officinalis (Amla) and rhizome of Curcuma longa (turmeric) in equal proportions. In the present study, the raw materials were procured from commercial suppliers, identified botanically and complied as per “IMPCOPS” (The Indian Medical Practitioners Co - Operative Pharmacy and Stores Ltd, Madras). Nisamalaki churna was prepared as per “IMPCOPS” (in-house sample). It was tested as per pharmacopoeial guidelines. Parameters such as organoleptic characters, microscopic characters, physico-chemical parameters, TLC studies using curcumin and ascorbic acid as active phytomarkers, estimation of total tannins, heavy metals limit test and presence of aflatoxins (B1,G1,B2 and G2) were studied. Simultaneously, market samples of Nisamalaki churna were procured over the counter for comparison.

Impurities in Nitrile Solvents Commonly Used for Electrochemistry, and their Effects on Voltammetric Data

AbstractVoltammetry experiments were performed on 1,4‐benzoquinone and 1,4‐phenylenediamine in acetonitrile, propionitrile (from five commercial suppliers: Acros Organics, Aldrich, Alfa Aesar, Fluka, and Merck), and butyronitrile, to which different electrochemical responses were collected across the three nitrile solvents and within the five commercial brands of propionitrile, owing to the reduced (1,4‐benzoquinone) or oxidized (1,4‐phenylenediamine) compounds reacting with impurities in the solvents. Of the three solvents, propionitrile suffered from the most impurities, which adversely affected the electrochemical results. Distillation of the propionitrile over phosphorus pentoxide or passing it through a flash column containing silica gel was partially effective in removing some of the impurities and resulted in the recovery of the familiar oxidation behavior of 1,4‐phenylenediamine. The reduction behavior of 1,4‐benzoquinone could be improved if propionitrile was purified by passing it through a column of basic activated alumina, thus a combination of distillation and flash chromatography is necessary to adequately purify propionitrile for reductive and oxidative voltammetry experiments. Purge and trap‐gas chromatography–mass spectrometry analyses positively identified 2‐methyl‐2‐pentenal among the impurities, but it was discovered to only have a mild effect on the voltammetric behavior of the quinone and not exert any influence on the electrochemical response of the phenylenediamine. The results of this study lead to the possibility of using the voltammetry of quinones and phenylenediamines as a sensitive method for determining the purity of organic solvents.

Effects of Filament Diameter Tolerances in Fused Filament Fabrication

Fused filament fabrication (FFF) is one of the most popular additive manufacturing (3D printing) technologies due to the growing availability of low-cost desktop 3D printers and the relatively low cost of the thermoplastic filament used in the 3D printing process. Commercial filament suppliers, 3D printer manufacturers, and end-users regard filament diameter tolerance as an important indicator of the 3D printing quality. Irregular filament diameter affects the flow rate during the filament extrusion, which causes poor surface quality, extruder jams, irregular gaps in-between individual extrusions, and/or excessive overlap, which eventually results in failed 3D prints. Despite the important role of the diameter consistency in the FFF process, few studies have addressed the required tolerance level to achieve highest 3D printing quality. The objective of this work is to develop the testing methods to measure the filament tolerance and control the filament fabrication process. A pellet-based extruder is utilized to fabricate acrylonitrile butadiene styrene (ABS) filament using a nozzle of 1.75 mm in diameter. Temperature and extrusion rate are controlled parameters. An optical comparator and an array of digital calipers are used to measure the filament diameter. The results demonstrate that it is possible to achieve high diameter consistency and low tolerances (0.01mm) at low extrusion temperature (180 °C) and low extrusion rate (10 in/min).

New barrier encapsulation and lifetime assessment of printed organic photovoltaic modules

Organic photovoltaic (OPV) modules printed on plastic substrates are attracting worldwide attention due to advantages such as flexibility, large-scale printability, lightweight, and potential utility for new products. However, exposure to atmospheric oxygen and water vapour is known to cause rapid device degradation and OPV devices thus require encapsulation using materials having ultra-low permeability to these atmospheric constituents to achieve the required operational lifetimes for commercial applications. In this work, various encapsulation architectures using flexible barrier films and adhesives available from commercial suppliers are developed and the lifetime of encapsulated large-area (active area ~50cm2) fully-printed OPV modules are assessed under ambient laboratory and outdoor conditions. New encapsulation architectures significantly enhance the durability of printed OPV modules, with results showing modules exhibiting a shelf-life of more than 5 years, and no evidence of degradation after 13 months׳ exposure under outdoor conditions.

Stronger Interference of Avian Influenza Virus-Specific Than Newcastle Disease Virus-Specific Maternally Derived Antibodies with a Recombinant NDV-H5 Vaccine.

Maternally derived antibodies (MDA) are known to provide early protection from disease but also to interfere with vaccination efficacy of young chicks. This interference phenomenon is well described in the literature for viral diseases such as infectious bursal disease, Newcastle disease (ND), and avian influenza (AI). The goal of this work was to investigate the impact of H5 MDA and/or ND virus (NDV) MDA on the vaccine efficacy of a recombinant NDV-H5-vectored vaccine (rNDV-H5) against two antigenically divergent highly pathogenic AI (HPAI) H5N1 challenges. In chickens with both H5 and NDV MDA, a strong interference was observed with reduced clinical protection when compared to vaccinated specific-pathogen-free (SPF) chickens. In contrast, in chickens from commercial suppliers with NDV MDA only, a beneficial impact on the vaccine efficacy was observed with full protection and reduced viral excretion in comparison with rNDV-H5-vaccinated SPF chickens. To distinguish between the respective effects of the H5 and NDV MDA, an SPF model where passive immunity had been artificially induced by inoculations of H5 and NDV hyperimmunized polysera, respectively, was used. In the presence of H5 artificial MDA, a strong interference reflected by a reduction in vaccine protection was demonstrated whereas no interference and even an enhancing protective effect was confirmed in presence of NDV MDA. The present work suggests that H5 and NDV MDA interact differently with the rNDV-H5 vaccine with different consequences on its efficacy, the mechanisms of which require further investigations.

Flavor and stability of milk proteins

A greater understanding of the nature and source of dried milk protein ingredient flavor(s) is required to characterize flavor stability and identify the sources of flavors. The objective of this study was to characterize the flavor and flavor chemistry of milk protein concentrates (MPC 70, 80, 85), isolates (MPI), acid and rennet caseins, and micellar casein concentrate (MCC) and to determine the effect of storage on flavor and functionality of milk protein concentrates using instrumental and sensory techniques. Spray-dried milk protein ingredients (MPC, MPI, caseins, MCC) were collected in duplicate from 5 commercial suppliers or manufactured at North Carolina State University. Powders were rehydrated and evaluated in duplicate by descriptive sensory analysis. Volatile compounds were extracted by solid phase microextraction followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry. Compounds were identified by comparison of retention indices, odor properties, and mass spectra against reference standards. A subset of samples was selected for further analysis using direct solvent extraction with solvent-assisted flavor extraction, and aroma extract dilution analysis. External standard curves were created to quantify select volatile compounds. Pilot plant manufactured MPC were stored at 3, 25, and 40°C (44% relative humidity). Solubility, furosine, sensory properties, and volatile compound analyses were performed at 0, 1, 3, 6, and 12 mo. Milk proteins and caseins were diverse in flavor and exhibited sweet aromatic and cooked/milky flavors as well as cardboard, brothy, tortilla, soapy, and fatty flavors. Key aroma active compounds in milk proteins and caseins were 2-aminoacetophenone, nonanal, 1-octen-3-one, dimethyl trisulfide, 2-acetyl-1-pyrroline, heptanal, methional, 1-hexen-3-one, hexanal, dimethyl disulfide, butanoic acid, and acetic acid. Stored milk proteins developed animal and burnt sugar flavors over time. Solubility of MPC decreased and furosine concentration increased with storage time and temperature. Solubility of MPC 80 was reduced more than that of MPC 45, but time and temperature adversely affected solubility of both proteins, with storage temperature having the greatest effect. Flavor and shelf stability of milk proteins provide a foundation of knowledge to improve the flavor and shelf-life of milk proteins.

Abstract A20: Decreased nuclear expression of the FRY protein identifies a subset of breast cancers with poor clinical outcomes

Abstract The goal of the present study was to determine if decreased nuclear expression of the human FRY protein can serve as a biomaker of breast cancer progression and outcomes. We previously identified the rat Fry gene as a putative mammary carcinoma susceptibility (Mcs) gene. We further demonstrated that FRY expression was decreased in several human breast cancer cell lines. Moreover, ectopic expression of wildtype Fry suppressed tumorigenicity of the triple negative MDA-MD-231 breast cancer cells in vitro and in vivo by promoting epithelial cell differentiation. To evaluate the contribution of altered FRY expression to the clinical progression of human breast cancer, we first compared FRY mRNA expression in &amp;gt;4,800 clinically annotated human breast cancers using DNA microarray data from 19 distinct cohorts available from the Oncomine 3.0 Cancer Profiling Database. The analysis indicated that decreased FRY mRNA was significantly correlated with poorly differentiated tumor histopathology, increased Elston tumor grade, and triple negative status (loss of estrogen, progesterone and Her2 receptors). Using commercially available breast cancer tissue microarrays, we used semi-quantitative immunohistochemistry and quantitative image analysis to compare FRY protein expression in normal mammary tissue and tumors. The results indicated that loss of FRY expression was a frequent event during progression of mammary carcinomas. We therefore analyzed &amp;gt;1200 clinically annotated breast cancers represented on tissue microarrays from commercial suppliers and the National Cancer Institute (NCI) Cancer Diagnosis Program, including the Breast Cancer Diagnosis and Progression panels. FRY protein expression was evaluated by immunohistochemical staining and was graded on a scale of 0 to 4 (0, +, ++, +++, ++++). The analysis indicated that decreased nuclear expression of the FRY protein was significantly correlated with poorly differentiated histopathologies, increasing Elston grade and loss of the estrogen receptor. Tumors with decreased FRY expression were also more likely to metastasize and were associated with decreased tumor-free survival. These findings indicated that loss of nuclear FRY expression identifies a subset of breast cancer with poor clinical outcomes, suggesting that FRY may serve as an early biomarker for breast cancer progression and prognosis. Citation Format: Helmut Zarbl, Jessica C. Graham, Norio Takizawa, Mingzhu Fang, Zhihong Gong, Brian Estrella, Xuefeng Ren. Decreased nuclear expression of the FRY protein identifies a subset of breast cancers with poor clinical outcomes. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A20.

Substrates and fertilizers for organic container production of herbs, vegetables, and herbaceous ornamental plants grown in greenhouses in the United States

The value of organic greenhouse production in the United States is $112 million, and organic floriculture production has increased 40% in greenhouses since 2008. The U.S. National Organic Program (NOP) guidelines allow organic production in containers. One of the primary concerns for current and potential organic container growers is managing container substrate and plant fertility. This manuscript provides a review of current literature on organic substrates and fertilizers for container grown herbs, vegetables and herbaceous ornamentals according to NOP guidelines. Organic-approved substrates can be purchased from commercial suppliers or produced in house. Many organic substrate components are similar to those used in conventional production (peat moss, pine bark, perlite, vermiculite, rice hulls, and whole pine tree) but lack a synthetic wetting agent. Growers who mix their own substrates often add compost at percentages ranging from 20 to 50%. Compost has high water holding and cation exchange capacity. It is often locally or regionally produced and purchased, which impacts variability and quality. For this reason, growers often need to manage substrates with compost more carefully. Single source or blended organic fertilizers may be incorporated in substrates prior to planting. These are derived from a variety of plant and animal based sources. A small number of mined components may be added to substrate-incorporated fertilizers (i.e. limestone). These fertilizers will typically last for four to five weeks, and are often supplemented with liquid fertilizers for longer-term crops or species with high nitrogen requirements. Liquid fertilizers also tend to be more quickly plant available compared to substrate-incorporated fertilizers. With careful management, it is possible to grow container plants in organic production systems that are comparable to those produced in conventional production systems.

Performance evaluation of conductive additives for activated carbon supercapacitors in organic electrolyte

In this study, we investigate two different activated carbons and four conductive additive materials, all produced in industrial scale from commercial suppliers. The two activated carbons differed in porosity: one with a narrow microporous pore size distribution, the other showed a broader micro-mesoporous pore structure. Electrochemical benchmarking was done in one molar tetraethylammonium tetrafluoroborate in acetonitrile. Comprehensive structural, chemical, and electrical characterization was carried out by varied techniques. This way, we correlate the electrochemical performance with composite electrode properties, such as surface area, pore volume, electrical conductivity, and mass loading for different admixtures of conductive additives to activated carbon. The electrochemical rate handling (from 0.1 Ag−1 to 10 Ag−1) and long-time stability testing via voltage floating (100h at 2.7V cell voltage) show the influence of functional surface groups on carbon materials and the role of percolation of additive particles.

Implementation of an HIV-1 Triple-Target NAT Assay in the Routine Screening at Three German Red Cross Blood Centres

Background: Blood product safety was significantly improved by the introduction of NAT testing in the late 1990s, resulting in a strong decrease of transfusion-transmitted infections (TTIs). Due to the occurrence of HIV-1 NAT test failures as a consequence of mismatch mutations in the amplicon regions of mono-target NAT assays, the Paul Ehrlich Institute mandated the implementation of multi-target NAT assays for HIV-1 in 2014. Commercial suppliers mostly developed dual-target NAT assays, with only one implementing a triple-target NAT assay. Methods: The HIV-1 triple-target NAT assay v3 (GFE Blut) was tested on mutated specimens and synthetic DNA bearing mutations that resulted in sample underquantification or false-negative test results. In addition, data from 2 years routine testing at three German Red Cross Blood centres were analysed. Results: The HIV-1 triple-target PCR could compensate for all mutations tested and could compensate the loss of one amplicon without a significant loss of sensitivity. Data from 2 years routine testing showed a solid performance. Conclusion: The HIV-1 triple-target v3 assay (GFE Blut) can compensate mutations in target sequences better than a dual-target assay and is applicable to high-throughput screening, thus increasing blood product safety.

Assesment of (Mn,Co)33O4 powders for possible coating material for SOFC/SOEC interconnects

In this work (Mn,Co)3O4 spinel powders with different Mn:Co ratio (1:1 and 1:2) and from different commercial suppliers are evaluated for possible powder for production of interconnect coatings. Sinterability of the powders is evaluated on pressed pellets sintered in oxidizing and in reducing/oxidizing atmospheres. For selected powder, coatings are then prepared by the electrophoretic deposition method on Crofer 22 APU stainless steel coupons. Effects of dispersant/iodine content and deposition voltage and times are evaluated. Thickness as a function of deposition parameters is described. Results show that with appropriate powder it is possible to produce adherent protective coating with a well-controlled thickness.

Open-source Selective Laser Sintering (OpenSLS) of nylon and biocompatible polycaprolactone

Event Abstract Back to Event Open-source Selective Laser Sintering (OpenSLS) of nylon and biocompatible polycaprolactone Ian S. Kinstlinger1, Andreas Bastian1, Daniel H. Hwang1, Anderson Ta1, Samantha J. Paulsen1, Tim Schmidt2 and Jordan S. Miller1 1 Rice University, Bioengineering, United States 2 Lansing Makers Association, United States Introduction: Selective Laser Sintering (SLS) is an additive manufacturing process in which a laser patterns powdered starting materials into solid 3D structures in a layer-by-layer manner. Features which are challenging to fabricate using other additive processes (e.g. overhangs, underhangs, branches, and bifurcations) are readily accessible using SLS. SLS has found great utility in the fabrication of scaffolds for bone tissue engineering[1] and patient-specific splints for human airway stabilization[2]. Despite the potential for fabrication of complex, high-resolution structures with SLS using diverse materials (including biomaterials), prohibitive costs of commercial systems have hindered the wide adoption of this technology in the scientific community. We hypothesized that a consumer laser cutter could be used in conjunction with open-source hardware and software to inexpensively perform SLS. Here, we implemented and characterized sintering with polymers and biomaterials, introduced post-processing techniques for sintered parts, and demonstrated biocompatibility of sintered polycaprolactone (PCL). Methods: We implemented OpenSLS by installing a custom powder handling module inside a laser cutter and overriding the native electronics[3]. Sintered parts were assessed by scanning electron microscopy (SEM) and microcomputed tomography (µCT). PCL biocompatibility was evaluated by seeding human mesenchymal stem cells (hMSC) labeled with GFP and H2B-mCherry on sintered PCL surfaces and imaging with epifluorescent microscopy. Results and Discussion: Nylon was sintered into structures with sub-millimeter features and overhanging/branching regions (Figure 1). Sintered surfaces appear similar to those of nylon parts fabricated on commercial SLS systems[4]. Nylon filaments exhibit a mostly fused core but show small irregular interior cavities. PCL was also sintered into lattice structures, which could be useful as bone scaffolds. Finding that coarse PCL grains yielded rough, poorly connected lattices, we developed a vapor smoothing technique (Figure 2) which reduced the average surface roughness from 120µm to 5µm and increased the elastic modulus from 30MPa to 60MPa. The stiffer scaffolds more closely match bone mechanics while the smoothed surfaces enhance cell adhesion. hMSCs attached, survived, and exhibited characteristic spindle-like morphology on both vapor-smoothed and unsmoothed sintered PCL (Figure 3), suggesting that sintered PCL will be useful for cell studies. Conclusions: Architecturally complex, physiologically relevant structures can be fabricated at high resolution using a low-cost, open-source platform. The use of biomaterials in this system is straightforward and produces structures that are compatible with cell studies. OpenSLS could serve the scientific community as an accessible platform for fabricating structures composed of a wide range of materials, including non-traditional materials not supported by commercial SLS suppliers. We gratefully acknowledge the many open-source and related projects that critically facilitated this work, including Arduino.cc, RepRap.org, Ultimachine.com, Python.org, Blender.org, NIH ImageJ, Fiji.sc, slic3r.org, netfabb.com, pronterface.com, enblend.sourceforge.net, thingiverse.com, and openscad.org.; We are grateful to SeeMeCNC for assisting with the acquisition, installation, and configuration of the laser cutter that was converted into OpenSLS.