Publications by authors named "Romberg B"

Following successes of authorized chimeric antigen receptor T-cell products being commercially marketed in the United States and European Union, product development of T-cell-based cancer immunotherapy consisting of cell-based advanced therapy medicinal products (ATMPs) has gained further momentum. Due to their complex characteristics, pharmacological properties of living cell products are, in contrast to classical biological drugs such as small molecules, more difficult to define. Despite the availability of many new advanced technologies that facilitate ATMP manufacturing, translation from research-grade to clinical-grade manufacturing in accordance with Good Manufacturing Practices (cGMP) needs a thorough product development process in order to maintain the same product characteristics and activity of the therapeutic product after full-scale clinical GMP production as originally developed within a research setting.

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The enzymatically degradable poly(amino acid)-lipid conjugate poly(hydroxyethyl l-glutamine)-N-succinyl-dioctadecylamine (PHEG-DODASuc) has been shown to effectively prolong liposome circulation times. In this paper, we investigated whether PHEG-DODASuc can stabilize liposomes composed of the fusogenic, non-bilayer-forming lipid dioleoyl phosphatidylethanolamine (DOPE). Moreover, we evaluated the release of an entrapped compound after enzyme-induced shedding of the PHEG-coating, interbilayer contact and membrane destabilizing phase changes.

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We prepared thermosensitive poly( N-(2-hydroxypropyl)methacrylamide mono/dilactate) (pHPMA mono/dilactate) polymer and studied temperature-triggered contents release from polymer-coated liposomes. HPMA mono/dilactate polymer was synthesized with a cholesterol anchor suitable for incorporation in the liposomal bilayers and with a cloud point (CP) temperature of the polymer slightly above normal body temperature (42 degrees C). Dynamic light scattering (DLS) measurements showed that whereas the size of noncoated liposomes remained stable upon raising the temperature from 25 to 46 degrees C, polymer-coated liposomes aggregated around 43 degrees C.

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A major hurdle towards in vivo utilization of pH-sensitive liposomes is their prompt sequestration by reticuloendothelial system and hence short circulation time. Prolonged circulation of liposomes is usually achieved by incorporation of pegylated lipids, which have been frequently reported to deteriorate the acid-triggered release. In this study we evaluate the ability of four novel nonionic copolymers, bearing short blocks of lipid-mimetic units to provide steric stabilization of DOPE:CHEMs liposomes.

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Long-circulating liposomes, such as PEG-liposomes, are frequently studied for drug delivery and diagnostic purposes. In our group, poly(amino acid) (PAA)-based coatings for long-circulating liposomes have been developed. These coatings provide liposomes with similar circulation times as compared to PEG-liposomes, but have the advantage of being enzymatically degradable.

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Nanoparticles, such as liposomes, polymeric micelles, lipoplexes and polyplexes are frequently studied as targeted drug carrier systems. The ability of these particles to circulate in the bloodstream for a prolonged period of time is often a prerequisite for successful targeted delivery. To achieve this, hydrophilic 'stealth' polymers, such as poly(ethylene glycol) (PEG), are used as coating materials.

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'Stealth' liposomes with a poly(ethylene glycol) (PEG) coating are frequently studied for drug delivery and diagnostic purposes because of their prolonged blood circulation kinetics. However, several recent reports have demonstrated that PEG-liposomes are rapidly cleared at single low lipid doses (<1 micromol/kg) and upon repeated administration (time interval between the injections 5 days-4 weeks). Recently, poly(amino acid)-based stealth liposome coatings have been developed as alternative to the PEG-coating.

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Poly(amino acid)s (PAAs) were evaluated as coating polymers for long-circulating liposomes. The pharmacokinetics of PAA-coated liposomes were assessed in rats. Prolonged circulation times were obtained, comparable to those reported for poly(ethylene glycol) (PEG)-liposomes.

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Liposomes coated with the poly(amino acid) poly(hydroxyethyl-L-asparagine) (PHEA) show long-circulation properties comparable to the frequently used PEG-liposomes. The pharmacokinetic characteristics of long-circulating liposomes are dependent on the density of the shielding polymer on the liposome surface. Therefore, it is necessary to know the exact composition of the liposomes including the amount of coating polymer present on the liposome surface.

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Liposomes coated with poly(hydroxyethyl L-glutamine) (PHEG) show prolonged circulation times and biodistribution patterns comparable to PEG-coated liposomes. While PEG is a nondegradable polymer, PHEG is expected to be hydrolyzed by proteases. In this study the enzymatic degradability of PHEG both in its free form and grafted onto liposomes was investigated, using the proteases papain, pronase E, and cathepsin B.

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A 26-year-old man, practicing for a variety performance as "fire-eater", accidentally inhaled and ingested about 10 ml petroleum. Soon afterwards he developed dyspnoea, an urge to cough, fever up to 39 degrees C and loss of retentiveness. He was treated as an out-patient with doxycycline, 100 mg daily, and aspirin, 500 mg three times daily.

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The aim of the study was to determine the pulmonary 67-gallium uptake, bronchoalveolar lavage (BAL) cell differentiation and the activity of BAL cells, measured as release of superoxide anion (O2-), and to investigate the results whether there are relations. In 11 nonsmoking systemic scleroderma (SS) patients and 11 systemic lupus erythematosus (SLE) patients with lung involvement double-sided BAL were performed, mainly in regions with increased 67-gallium uptake. Release of O2- was measured by INT-assey.

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A procedure for the in vitro growth of well-ordered two-dimensional sheets from ribosomal particles using salts and salt-alcohol mixtures has been developed. Employing this procedure, ordered two-dimensional sheets of the wild type as well as of mutated 50 S ribosomal subunits from Bacillus stearothermophilus can readily be obtained. These sheets, stained with uranyl acetate or gold-thioglucose, are suitable for three-dimensional image reconstruction.

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Six proteins (B-L1, B-L6, B-L10, B-L11, B-L12 and B-L16) were removed from 50S ribosomal subunits of Bacillus stearothermophilus by treatment with ethanol and ammonium chloride. The proteins were isolated in a pure form, and one of them (B-L6) was crystallized. Five of the six proteins (in various combinations) were added back to the core particles, resulting in 50S subunits lacking one protein.

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