57 results match your criteria macrobeads

Tissue factor-loaded collagen/alginate hydrogel beads as a hemostatic agent.

J Biomed Mater Res B Appl Biomater 2020 Dec 23. Epub 2020 Dec 23.

State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, China.

Uncontrolled hemorrhage accounts for a significant proportion of annual mortality worldwide. The development of bioinspired hemostatic composites can effectively reduce hemorrhage and related deaths. This work aims to develop an efficient hemostatic agent by incorporating tissue factor (TF) integrated liposomes and collagen, which are capable of augmenting different inherent hemostatic mechanisms, into hemostasis-stimulating alginate matrix. Read More

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December 2020

MEF2 plays a significant role in the tumor inhibitory mechanism of encapsulated RENCA cells via EGF receptor signaling in target tumor cells.

BMC Cancer 2018 Dec 4;18(1):1217. Epub 2018 Dec 4.

The Rogosin Institute-Xenia Division, 740 Birch Road, Xenia, OH, 45385, USA.

Background: Agarose encapsulated murine renal adenocarcinoma cells (RENCA macrobeads) are currently being investigated in clinical trials as a treatment for therapy-resistant metastatic colorectal cancer. We have previously demonstrated the capacity of RENCA macrobeads to produce diffusible substances that markedly inhibit the proliferation of epithelial-derived tumor cells outside the macrobead environment. This study examined the molecular mechanisms underlying the observed inhibition in targeted tumor cells exposed to RENCA macrobeads. Read More

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December 2018

A novel, green, low-cost chitosan-starch hydrogel as potential delivery system for plant growth-promoting bacteria.

Carbohydr Polym 2018 Dec 30;202:409-417. Epub 2018 Jul 30.

Laboratorio Bioquímica Vegetal y Microbiana, Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Ruta 226, Km 73.5, Balcarce, B7620, Argentina. Electronic address:

The study examines the use of macrobeads for the controlled-release of bacteria. Macrobeads were prepared by an easy dripping-technique using 20/80 wt/wt chitosan-starch blends and sodium tripolyphosphate as cross-linking agent. The resulting polymeric matrix was examined by SEM, XRD, TGA, and solid-RMN. Read More

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December 2018

A model for determining an effective in vivo dose of transplanted islets based on in vitro insulin secretion.

Xenotransplantation 2018 11 28;25(6):e12443. Epub 2018 Jul 28.

Xenia Division, The Rogosin Institute, Xenia, Ohio.

Background: Allogeneic islet transplantation for the treatment of type 1 diabetes often requires multiple implant procedures, from as many as several human pancreas donors, to achieve lasting clinical benefit. Given the limited availability of human pancreases for islet isolation, porcine islets have long been considered a potential option for clinical use. Agarose-encapsulated porcine islets (macrobeads) permit long-term culture and thus a thorough evaluation of microbiological safety and daily insulin secretory capacity, prior to implantation. Read More

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November 2018

Sustainable Flow Synthesis of Encoded Beads for Combinatorial Chemistry and Chemical Biology.

ACS Comb Sci 2018 08 18;20(8):492-498. Epub 2018 Jul 18.

Center for Evolutionary Chemical Biology, Department of Chemistry University of Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark.

Monosized beads of polar resins were synthesized for combinatorial chemistry and chemical biology by sustainable microchannel flow synthesis. Regular, biocompatible, and optically encoded beads could be efficiently prepared on large scale and in high yield. In a preparative flow polymerization instrument, taking advantage of a designed T-connector for droplet formation, quality beads were synthesized with accurate size control using a minimal amount of recirculating silicon oil as suspension medium. Read More

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Gellan gum macrobeads loaded with naproxen: The impact of various naturally derived polymers on pH-dependent behavior.

J Biomater Appl 2018 07 6;33(1):140-155. Epub 2018 Jun 6.

3 Poznan University of Technology, Faculty of Technical Physics, Poznań, Poland.

Aims After oral administration, naproxen generates several side-effects related to stomach malfunction. Undoubtedly, the enteric dosage forms with naproxen can be considered as safer. Moreover, since it has been evidenced that development and growth of colorectal cancer is related to the presence of cyclooxygenase, naproxen is investigated in terms of the tumor prevention. Read More

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Clinical laboratory and imaging evidence for effectiveness of agarose-agarose macrobeads containing stem-like cells derived from a mouse renal adenocarcinoma cell population (RMBs) in treatment-resistant, advanced metastatic colorectal cancer: Evaluation of a biological-systems approach to cancer therapy (U.S. FDA IND-BB 10091; NCT 02046174, NCT 01053013).

Chin J Cancer Res 2018 Feb;30(1):72-83

The Rogosin Institute, New York NY 10021, USA.

Objective: The complexity, heterogeneity and capacity of malignant neoplastic cells and tumors for rapid change and evolution suggest that living-cell-based biological-systems approaches to cancer treatment are merited. Testing this hypothesis, the tumor marker, metabolic activity, and overall survival (OS) responses, to the use of one such system, implantable macrobeads [RENCA macrobeads (RMBs)], in phase I and IIa clinical trials in advanced, treatment-resistant metastatic colorectal cancer (mCRC) are described here.

Methods: Forty-eight mCRC patients (30 females; 18 males), who had failed all available, approved treatments, underwent RMB implantation (8 RMB/kg body weight) up to 4 times in phase I and phase IIa open-label trials. Read More

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February 2018

Colorectal Carcinoma: A General Overview and Future Perspectives in Colorectal Cancer.

Int J Mol Sci 2017 Jan 19;18(1). Epub 2017 Jan 19.

Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, 50013 Zaragoza, Spain.

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death. Most cases of CRC are detected in Western countries, with its incidence increasing year by year. The probability of suffering from colorectal cancer is about 4%-5% and the risk for developing CRC is associated with personal features or habits such as age, chronic disease history and lifestyle. Read More

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January 2017

A comprehensive microbiological safety approach for agarose encapsulated porcine islets intended for clinical trials.

Xenotransplantation 2016 11 11;23(6):444-463. Epub 2016 Nov 11.

Department of Surgery, Weill Medical College of Cornell University and NewYork-Presbyterian Hospital, New York, NY, USA.

Background: The use of porcine islets to replace insulin-producing islet β-cells, destroyed during the diabetogenic disease process, presents distinct challenges if this option is to become a therapeutic reality for the treatment of type 1 diabetes. These challenges include a thorough evaluation of the microbiological safety of the islets. In this study, we describe a robust porcine islet-screening program that provides a high level of confidence in the microbiological safety of porcine islets suitable for clinical trials. Read More

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November 2016

First-in-Human Phase 1 Trial of Agarose Beads Containing Murine RENCA Cells in Advanced Solid Tumors.

Cancer Growth Metastasis 2016 2;9:9-20. Epub 2016 Aug 2.

New York Presbyterian-Weill Cornell Medical Center, New York, NY, USA.

Purpose: Agarose macrobeads containing mouse renal adenocarcinoma cells (RMBs) release factors, suppressing the growth of cancer cells and prolonging survival in spontaneous or induced tumor animals, mediated, in part, by increased levels of myocyte-enhancing factor (MEF2D) via EGFR-and AKT-signaling pathways. The primary objective of this study was to determine the safety of RMBs in advanced, treatment-resistant metastatic cancers, and then its efficacy (survival), which is the secondary objective.

Methods: Thirty-one patients underwent up to four intraperitoneal implantations of RMBs (8 or 16 macrobeads/kg) via laparoscopy in this single-arm trial (FDA BB-IND 10091; NCT 00283075). Read More

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No evidence of viral transmission following long-term implantation of agarose encapsulated porcine islets in diabetic dogs.

J Diabetes Res 2014 5;2014:727483. Epub 2014 Jun 5.

The Rogosin Institute, New York, NY 10021, USA ; NewYork-Presbyterian Hospital, Weill Medical College of Cornell University, New York, NY 10021, USA.

We have previously described the use of a double coated agarose-agarose porcine islet macrobead for the treatment of type I diabetes mellitus. In the current study, the long-term viral safety of macrobead implantation into pancreatectomized diabetic dogs treated with pravastatin (n = 3) was assessed while 2 dogs served as nonimplanted controls. A more gradual return to preimplant insulin requirements occurred after a 2nd implant procedure (days 148, 189, and >652) when compared to a first macrobead implantation (days 9, 21, and 21) in all macrobead implanted animals. Read More

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February 2015

Pravastatin improves glucose regulation and biocompatibility of agarose encapsulated porcine islets following transplantation into pancreatectomized dogs.

J Diabetes Res 2014 19;2014:405362. Epub 2014 May 19.

The Rogosin Institute, New York, NY 10021, USA ; NewYork-Presbyterian Hospital and Weill Medical College of Cornell University, New York, NY 10021, USA.

The encapsulation of porcine islets is an attractive methodology for the treatment of Type I diabetes. In the current study, the use of pravastatin as a mild anti-inflammatory agent was investigated in pancreatectomized diabetic canines transplanted with porcine islets encapsulated in agarose-agarose macrobeads and given 80 mg/day of pravastatin (n = 3) while control animals did not receive pravastatin (n = 3). Control animals reached preimplant insulin requirements on days 18, 19, and 32. Read More

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February 2015

Treatment of agarose-agarose RENCA macrobeads with docetaxel selects for OCT4(+) cells with tumor-initiating capability.

Cancer Biol Ther 2013 Dec 12;14(12):1147-57. Epub 2013 Sep 12.

The Rogosin Institute; New York, NY USA; Department of Surgery; Weill Medical College of Cornell University; New York, NY USA; NewYork-Presbyterian Hospital; New York, NY USA.

The cancer stem cell (CSC) theory depicts such cells as having the capacity to produce both identical CSCs (symmetrical division) and tumor-amplifying daughter cells (asymmetric division). CSCs are thought to reside in niches similar to those of normal stem cells as described for neural, intestinal, and epidermal tissue, are resistant to chemotherapy, and are responsible for tumor recurrence. We recently described the niche-like nature of mouse renal adenocarcinoma (RENCA) cells following encapsulation in agarose macrobeads. Read More

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December 2013

Enhancement of in vitro and in vivo function of agarose-encapsulated porcine islets by changes in the islet microenvironment.

Cell Transplant 2014 29;23(8):929-44. Epub 2013 Apr 29.

The Rogosin Institute-Xenia Division, Xenia, OH, USA.

The transplantation of porcine islets of Langerhans to treat type 1 diabetes may provide a solution to the demand for insulin-producing cells. Porcine islets encapsulated in agarose-agarose macrobeads have been shown to function in nonimmunosuppressed xenogeneic models of both streptozotocin-induced and autoimmune type 1 diabetes. One advantage of agarose encapsulation is the ability to culture macrobeads for extended periods, permitting microbiological and functional assessment. Read More

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Streptozotocin is responsible for the induction and progression of renal tumorigenesis in diabetic Wistar-Furth rats treated with insulin or transplanted with agarose encapsulated porcine islets.

Islets 2011 Jul-Aug;3(4):196-203. Epub 2011 Jul 1.

The Rogosin Institute-Xenia Division, Xenia, OH, USA.

Streptozotocin (STZ), a nitrosourea with DNA alkylating properties, has been widely used to induce hyperglycemia by specifically destroying the insulin-producing β-cells of the islets of Langerhans in experimental models of Type I diabetes. STZ's known carcinogenic properties, however, raise concerns about its suitability for long-term studies. We conducted a formal study of STZ's carcinogenic effects in long-term surviving diabetic Wistar-Furth rats. Read More

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November 2011

Three-dimensional culture of mouse renal carcinoma cells in agarose macrobeads selects for a subpopulation of cells with cancer stem cell or cancer progenitor properties.

Cancer Res 2011 Feb 24;71(3):716-24. Epub 2011 Jan 24.

The Rogosin Institute, New York, New York 10021, USA.

The culture of tumor cell lines in three-dimensional scaffolds is considered to more closely replicate the in vivo tumor microenvironment than the standard method of two-dimensional cell culture. We hypothesized that our method of encapsulating and maintaining viable and functional pancreatic islets in agarose-agarose macrobeads (diameter 6-8 mm) might provide a novel method for the culture of tumor cell lines. In this report we describe and characterize tumor colonies that form within macrobeads seeded with mouse renal adenocarcinoma cells. Read More

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February 2011

Hydrophilic agarose macrobead cultures select for outgrowth of carcinoma cell populations that can restrict tumor growth.

Cancer Res 2011 Feb 24;71(3):725-35. Epub 2011 Jan 24.

The Rogosin Institute, New York, New York 10021, USA.

Cancer cells and their associated tumors have long been considered to exhibit unregulated proliferation or growth. However, a substantial body of evidence indicates that tumor growth is subject to both positive and negative regulatory controls. Here, we describe a novel property of tumor growth regulation that is neither species nor tumor-type specific. Read More

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February 2011

A strategy for the engineering of insulin producing cells with a broad spectrum of defense properties.

Biomaterials 2011 Mar 7;32(7):1816-25. Epub 2010 Dec 7.

Diabetes and Obesity Research Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Beilinson Campus, Petah Tikva 49100, Israel.

Insulin-producing pancreatic beta cells are known to be extremely susceptible to the oxidative stress and hypoxia generated following islet transplantation in diabetic patients. We hereby present a novel in vivo selection strategy based on the isolation of insulin-producing cells with enhanced protection after repeated rounds of encapsulation and xenotransplantation. Rat insulinoma INS-1 cells were encapsulated in alginate macrobeads and transplanted in the peritoneal cavity of mice. Read More

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Prediction models for shape and size of ca-alginate macrobeads produced through extrusion-dripping method.

J Colloid Interface Sci 2009 Oct 19;338(1):63-72. Epub 2009 May 19.

Centre of Materials and Minerals, School of Engineering and Information Technology, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah, Malaysia.

The aim of this work was to develop prediction models for shape and size of ca-alginate macrobeads produced through extrusion-dripping method. The relationship between the process variables on the shape and size of the alginate drops before and after gelation was established with the aid of image analysis. The results show that a critical Ohnersorge number (Oh)>0. Read More

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October 2009

Improved glucose regulation on a low carbohydrate diet in diabetic rats transplanted with macroencapsulated porcine islets.

Cell Transplant 2008 ;17(5):567-75

Rogosin Institute, Xenia Division, Xenia, OH 45385, USA.

Islet xenografts from porcine donors can reverse diabetes in experimental animal models and may be an alternative to human islet transplantation. We have recently reported the ability of porcine islets encapsulated in a double layer of hydrophilic agarose to maintain in vitro functional ability for >6 months. Although beta-cells are capable of adapting their secretory capacity in response to glucose levels, evidence has shown that prolonged hyperglycemia can compromise this ability. Read More

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January 2009

Exploring the feasibility of selective depletion of T lymphocyte subsets by whole blood immunoadsorption cytapheresis.

Clin Exp Immunol 2007 Dec 9;150(3):477-86. Epub 2007 Oct 9.

Section of Hematology and Oncology, Department of Medicine, Boston University Medical Center, Boston, MA, USA.

Normal turnover of T lymphocytes is slow relative to other blood cells. Consequently, the physical removal of circulating leucocytes by thoracic duct drainage, repeated leukapheresis or blood filtration results in T cell depletion and immunosuppression. However, clinical use of such procedures is impractical compared with immunosuppressive drugs or radiation. Read More

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December 2007

Encapsulation of porcine islets permits extended culture time and insulin independence in spontaneously diabetic BB rats.

Cell Transplant 2007 ;16(6):609-20

The Rogosin Institute-Xenia Division, Xenia, OH 45385, USA.

The ability to culture porcine islets for extended times allows for both their functional assessment and the assurance of their microbiological safety prior to transplantation. We have previously shown that agarose-encapsulated porcine islets can be cultured for at least 24 weeks. In the current study, porcine islet agarose macrobeads cultured for up to 67 weeks were assessed for their ability to restore normoglycemia, respond to an intraperitoneal glucose challenge, maintain spontaneously diabetic BB rats free of insulin therapy for more than 6 months, and for their biocompatibility. Read More

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November 2007

Solution- and solid-phase, modular approaches for obtaining different natural product-like polycyclic architectures from an aminoindoline scaffold for combinatorial chemistry.

J Comb Chem 2006 Nov-Dec;8(6):856-71

Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario, Canada, K1A 0R6.

With the goal of developing a modular approach leading to different indoline alkaloid natural-product-like tricyclic derivatives having an unsaturated lactam (see compounds 13, 14, and 16), an aminoindoline-based bicyclic scaffold 10 was obtained from 9. The selective deprotection of the indoline NTeoc or benzylic NHAlloc in compound 10, followed by N-acryloylation and then subjection to a ring-closing metathesis reaction, successfully led to obtaining two different architectures (13/14 and 16) having an unsaturated lactam functionality. This modular solution-phase methodology was then developed on solid phase. Read More

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January 2007

High-throughput sequence determination of cyclic peptide library members by partial Edman degradation/mass spectrometry.

J Am Chem Soc 2006 Oct;128(39):13000-9

Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.

Cyclic peptides provide attractive lead compounds for drug discovery and excellent molecular probes in biomedical research. Large combinatorial libraries of cyclic peptides can now be routinely synthesized by the split-and-pool method and screened against biological targets. However, post-screening sequence determination of hit peptides has been problematic. Read More

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October 2006

Efficient synthesis of a beta-peptide combinatorial library with microwave irradiation.

J Am Chem Soc 2005 Sep;127(38):13271-80

Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.

The predictable relationship between beta-amino acid sequence and folding has inspired several biological applications of beta-peptides. For many such applications, it would be desirable to prepare and screen beta-peptide libraries. However, standard peptide synthesis protocols are not efficient enough to support a library approach for many types of beta-peptides. Read More

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September 2005

The use of confocal laser scanning microscopy to study the transport of biomacromolecules in a macroporous support.

J Chromatogr B Analyt Technol Biomed Life Sci 2005 Apr;818(1):89-97

Department of Chemical Engineering, University of Nebraska, 207L Othmer Hall, Lincoln, NE 68588-0463, USA.

Large-pore materials or supports resembling polymer conduits are used as packing material in chromatographic operations. Our ongoing research has shown that, when modified with peptides or ligands, chitosan beads that are 800 microm in diameter and have 3.5% solids can be used as matrices in bioseparations. Read More

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A library of spirooxindoles based on a stereoselective three-component coupling reaction.

J Am Chem Soc 2004 Dec;126(49):16077-86

Program in Chemical Biology, Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02138, USA.

A collection of structurally complex and chemically diverse small molecules is a useful tool to explore cell circuitry. In this article, we report the split-pool synthesis of more than 3000 spirooxindoles on high capacity macrobeads. The key reaction to assemble the spirooxindole core stereoselectively is a Lewis acid variant of the Williams' three-component coupling. Read More

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December 2004

Syntheses of stereochemically diverse nine-membered ring-containing biaryls.

Org Lett 2004 Oct;6(22):4021-4

Department of Chemistry and Chemical Biology, Howard Hughes Medical Institute, Harvard University, and the Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02138, USA.

[reaction: see text] A library of nine-membered, biaryl-containing rings has been synthesized in parallel on polystyrene macrobeads. Dimeric medium rings were shown to be accessible via a regio- and stereoselective double cyclization. Read More

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October 2004

Evaluation of microbeads of calcium alginate as a fluidized bed medium for affinity chromatography of Aspergillus niger Pectinase.

Biotechnol Prog 2004 Sep-Oct;20(5):1490-5

Chemistry Department, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India.

Calcium alginate microbeads (212-425 microm) were prepared by spraying 2% (w/v) alginate solution into 1 M CaCl2 solution. The fluidization behavior of these beads was studied, and the bed expansion index and terminal velocity were found to be 4.3 and 1808 cm h(-1), respectively. Read More

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Demonstration of the feasibility of a direct solid-phase split-pool Biginelli synthesis of 3,4-dihydropyrimidinones.

Org Lett 2004 Sep;6(19):3237-40

Harvard Institute of Chemistry and Cell Biology, Harvard Medical School, 250 Longwood Avenue, Boston, Massachusetts 02115, USA.

[reaction: see text] A direct, Lewis acid-catalyzed Biginelli synthesis of 3,4-dihydropyrimidinones has been performed on high-capacity polystyrene macrobeads with a polymer O-silyl-attached N-(3-hydroxypropyl)urea. Resin-urea was first reacted separately with either 4-bromo- or 4-chlorobenzaldehyde and LiOTf in MeCN at 80 degrees C. After washing, the beads were pooled and reacted with ethyl acetoacetate and LiOTf in MeCN at 80 degrees C. Read More

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September 2004