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Amara I, Germershaus O, Lentes C, Sass S, Youmto SM, Stracke JO, Clemens-Hemmelmann M, Assfalg A. Comparison of Protein-like Model Particles Fabricated by Micro 3D Printing to Established Standard Particles. J Pharm Sci 2024:S0022-3549(24)00137-0. [PMID: 38615817 DOI: 10.1016/j.xphs.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/16/2024]
Abstract
Innovative analytical instruments and development of new methods has provided a better understanding of protein particle formation in biopharmaceuticals but have also challenged the ability to obtain reproducible and reliable measurements. The need for protein-like particle standards mimicking the irregular shape, translucent nature and near-to-neutral buoyancy of protein particles remained one of the hot topics in the field of particle detection and characterization in biopharmaceutical formulations. An innovative protein-like particle model has been developed using two photo polymerization (2PP) printing allowing to fabricate irregularly shaped particles with similar properties as protein particles at precise size of 50 µm and 150 µm, representative of subvisible particles and visible particles, respectively. A study was conducted to compare the morphological, physical, and optical properties of artificially generated protein particles, polystyrene spheres, ETFE, and SU-8 particle standards, along with newly developed protein-like model particles manufactured using 2PP printing. Our results suggest that 2PP printing can be used to produce protein-like particle standards that might facilitate harmonization and standardization of subvisible and visible protein particle characterization across laboratories and organizations.
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Affiliation(s)
- Ilias Amara
- Pharmaceutical Development & Supplies, Pharmaceutical Technical Development Biologics Europe, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland; Institute of Pharma Technology, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Hofackerstrasse 30, 4132 Muttenz, Switzerland; Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, CH-4059 Basel, Switzerland
| | - Oliver Germershaus
- Institute of Pharma Technology, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Hofackerstrasse 30, 4132 Muttenz, Switzerland.
| | - Christopher Lentes
- Pharmaceutical Development & Supplies, Pharmaceutical Technical Development Biologics Europe, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland.
| | - Steffen Sass
- Pharma Technical Development, Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Germany
| | - Stephany Mamdjo Youmto
- Pharma Technical Development, Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Germany
| | - Jan Olaf Stracke
- Analytical Development and Quality Control, Pharmaceutical Technical Development Biologics Europe, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Mirjam Clemens-Hemmelmann
- Pharmaceutical Development & Supplies, Pharmaceutical Technical Development Biologics Europe, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Anacelia Assfalg
- Analytical Development and Quality Control, Pharmaceutical Technical Development Biologics Europe, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
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Gregoritza K, Theodorou C, Heitz M, Graf T, Germershaus O, Gregoritza M. Enzymatic degradation pattern of polysorbate 20 impacts interfacial properties of monoclonal antibody formulations. Eur J Pharm Biopharm 2024; 194:74-84. [PMID: 38042510 DOI: 10.1016/j.ejpb.2023.11.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/25/2023] [Accepted: 11/27/2023] [Indexed: 12/04/2023]
Abstract
Polysorbate 20 (PS20) is widely used to maintain protein stability in biopharmaceutical formulations. However, PS20 is susceptible to hydrolytic degradation catalyzed by trace amounts of residual host cell proteins present in monoclonal antibody (mAb) formulations. The resulting loss of intact surfactant and the presence of PS20 degradation products, such as free fatty acids (FFAs), may impair protein stability. In this study, two hydrolytically-active immobilized lipases, which primarily targeted either monoester or higher-order ester species in PS20, were used to generate partially-degraded PS20. The impact of PS20 degradation pattern on critical micelle concentration (CMC), surface tension, interfacial rheology parameters and agitation protection was assessed. CMC was slightly increased upon monoester degradation, but significantly increased upon higher-order ester degradation. The PS20 degradation pattern also significantly impacted the dynamic surface tension of a mAb formulation, whereas changes in the equilibrium surface tension were mainly caused by the adsorption of FFAs onto the air-water interface. In an agitation protection study, monoester degradation resulted in the formation of soluble mAb aggregates and proteinaceous particles, suggesting that preferential degradation of PS20 monoester species can significantly impair mAb stability. Additional mAbs should be tested in the future to assess the impact of the protein format.
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Affiliation(s)
- Kathrin Gregoritza
- Pharmaceutical and Processing Development, Pharma Technical Development Biologics Europe, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
| | - Christos Theodorou
- Pharmaceutical and Processing Development, Pharma Technical Development Biologics Europe, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Marc Heitz
- Pharmaceutical and Processing Development, Pharma Technical Development Biologics Europe, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Tobias Graf
- Analytical Development and Quality Control, Pharma Technical Development Biologics Europe, Roche Diagnostics GmbH, Penzberg, Germany
| | - Oliver Germershaus
- Institute for Pharma Technology, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Manuel Gregoritza
- Analytical Development and Quality Control, Pharma Technical Development Biologics Europe, F. Hoffmann-La Roche Ltd, Basel, Switzerland
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3
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Brosig S, Cucuzza S, Serno T, Bechtold-Peters K, Buecheler J, Zivec M, Germershaus O, Gallou F. Not the Usual Suspects: Alternative Surfactants for Biopharmaceuticals. ACS Appl Mater Interfaces 2023. [PMID: 37450418 DOI: 10.1021/acsami.3c05610] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Therapeutically relevant proteins naturally adsorb to interfaces, causing aggregation which in turn potentially leads to numerous adverse consequences such as loss of activity or unwanted immunogenic reactions. Surfactants are ubiquitously used in biotherapeutics drug development to oppose interfacial stress, yet, the choice of the surfactant is extremely limited: to date, only polysorbates (PS20/80) and poloxamer 188 are used in commercial products. However, both surfactant families suffer from severe degradation and impurities of the raw material, which frequently increases the risk of particle generation, chemical protein degradation, and potential adverse immune reactions. Herein, we assessed a total of 40 suitable alternative surfactant candidates and subsequently performed a selection through a three-gate screening process employing four protein modalities encompassing six different formulations. The screening is based on short-term agitation-induced aggregation studies coupled to particle analysis and surface tension characterization, followed by long-term quiescence stability studies connected to protein purity measurements and particle analysis. The study concludes by assessing the surfactant's chemical and enzymatic degradation propensity. The candidates emerging from the screening are de novo α-tocopherol-derivatives named VEDG-2.2 and VEDS, produced ad hoc for this study. They display protein stabilization potential comparable or better than polysorbates together with an increased resistance to chemical and enzymatic degradation, thus representing valuable alternative surfactants for biotherapeutics.
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Affiliation(s)
- Sebastian Brosig
- Novartis Pharma AG, GDD, TRD Biologics & CGT, Basel CH-4002, Switzerland
| | - Stefano Cucuzza
- Novartis Pharma AG, GDD, TRD Biologics & CGT, Basel CH-4002, Switzerland
| | - Tim Serno
- Novartis Pharma AG, GDD, TRD Biologics & CGT, Basel CH-4002, Switzerland
| | | | - Jakob Buecheler
- Novartis Pharma AG, GDD, TRD Biologics & CGT, Basel CH-4002, Switzerland
| | - Matej Zivec
- Novartis Pharma AG, GDD, TRD Biologics & CGT, Menges 1234, Slovenia
| | - Oliver Germershaus
- School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Hofackerstrasse 30, Muttenz 4132, Switzerland
| | - Fabrice Gallou
- Novartis Pharma AG, GDD, CHAD, Basel CH-4057, Switzerland
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4
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Koch F, Ekat K, Kilian D, Hettich T, Germershaus O, Lang H, Peters K, Kreikemeyer B. A Versatile Biocompatible Antibiotic Delivery System Based on Self-Assembling Peptides with Antimicrobial and Regenerative Potential. Adv Healthc Mater 2019; 8:e1900167. [PMID: 30985084 DOI: 10.1002/adhm.201900167] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/20/2019] [Indexed: 12/16/2022]
Abstract
Periodontitis is a chronic inflammatory and tissue-destructive disease. Since the polymicrobiome in the oral cavity makes it difficult to treat, novel therapeutic strategies are required. Hydrogels based on self-assembling peptides (SAP) can be suitable candidates for periodontal therapy due to their injectability, biocompatibility, cargo-loading capacity, and tunable physicochemical and mechanical properties. In this study, two SAP hydrogels (P11-4 and P11-28/29) are examined for their intrinsic antimicrobial activity, regenerative potential, and antibiotic delivery capacity. A significant antibacterial effect of P11-28/29 hydrogels on the periodontal pathogen Porphyromonas gingivalis and a less pronounced effect for P11-4 hydrogels is demonstrated. The metabolic activity rates of human dental follicle stem cells (DFSCs), which reflect cell viability and may thus indicate the regenerative capacity, are similar on tissue culture polystyrene (TCPS) and on P11-4 hydrogels after 14 days of culture. Noticeably, both SAP hydrogels strengthen the osteogenic differentiation of DFSCs compared with TCPS. The incorporation of tetracycline, ciprofloxacin, and doxycycline does not affect fibril formation of either SAP hydrogel and results in favorable release kinetics up to 120 h. In summary, this study reveals that P11-SAP hydrogels combine many favorable properties required to make them applicable as prospective novel treatment strategy for periodontal therapy.
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Affiliation(s)
- Franziska Koch
- School of Life SciencesInstitute for Chemistry and BioanalyticsUniversity of Applied Sciences and Arts Northwestern Switzerland 4132 Muttenz Switzerland
- Institute of Medical MicrobiologyVirology and HygieneUniversity Medicine Rostock 18057 Rostock Germany
- Department of Cell BiologyUniversity Medicine Rostock 18057 Rostock Germany
| | - Katharina Ekat
- Institute of Medical MicrobiologyVirology and HygieneUniversity Medicine Rostock 18057 Rostock Germany
- Department of Cell BiologyUniversity Medicine Rostock 18057 Rostock Germany
- Clinic for Restorative Dentistry and PeriodontologyUniversity Medicine Rostock 18057 Rostock Germany
| | - David Kilian
- School of Life SciencesInstitute for Chemistry and BioanalyticsUniversity of Applied Sciences and Arts Northwestern Switzerland 4132 Muttenz Switzerland
| | - Timm Hettich
- School of Life SciencesInstitute for Chemistry and BioanalyticsUniversity of Applied Sciences and Arts Northwestern Switzerland 4132 Muttenz Switzerland
| | - Oliver Germershaus
- School of Life SciencesInstitute of Pharma TechnologyUniversity of Applied Sciences and Arts Northwestern Switzerland 4132 Muttenz Switzerland
| | - Herrmann Lang
- Clinic for Restorative Dentistry and PeriodontologyUniversity Medicine Rostock 18057 Rostock Germany
| | - Kirsten Peters
- Department of Cell BiologyUniversity Medicine Rostock 18057 Rostock Germany
| | - Bernd Kreikemeyer
- Institute of Medical MicrobiologyVirology and HygieneUniversity Medicine Rostock 18057 Rostock Germany
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5
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Peláez SS, Mahler HC, Herdlitschka C, Wertli T, Kahl M, Koulov A, Matter A, Singh SK, Widmer M, Germershaus O, Mathaes R. Comparing Physical Container Closure Integrity Test Methods and Artificial Leak Methodologies. PDA J Pharm Sci Technol 2019; 73:220-234. [PMID: 30651337 DOI: 10.5731/pdajpst.2018.009332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The sterility of drug products intended for parenteral administration is a critical quality attribute (CQA) because it serves to ensure patient safety and is thus a key requirement by health authorities. While sterility testing is a probabilistic test, the assurance of sterility is a holistic concept including adequate design of manufacturing facilities, process performance, and product design. Container closure integrity testing (CCIT) is necessary to confirm the integrity of a container closure system (CCS), until the end of a product's shelf life. The new and revised United States Pharmacopeia (USP) General Chapter <1207> is a comprehensive guidance on CCI. Nevertheless, practical considerations including the choice of CCIT methods, the acceptance criteria, or the positive control samples (artificial leaks) must be addressed by the pharmaceutical manufacturer.This study is the first to provide a systematic comparison of four commonly used physical CCIT (pCCIT) methods [Helium (He) leak, vacuum decay, laser-based headspace analysis (HSA), and dye ingress] and four commonly used modes of creating artificial leaks (laser-drilled micro holes, copper wire introduced leaks, and two types of capillary leaks).The results from these experiments provide comprehensive data to allow a direct comparison of the capabilities of the individual methods. The results confirmed that the He leak detection method, which is considered the "gold-standard" for pCCIT regarding method sensitivity, indeed demonstrates the highest detection sensitivity (lowest detection limit). In comparison to the dye ingress method, HSA and vacuum decay also demonstrated better detection sensitivity in our study.Capillary leaks with orifice diameter (capillary leak with flow according to an ideal orifice) and micro holes yielded similar leak rates, whereas capillaries with nominal diameters yielded significantly lower leak rates. In conclusion, method sensitivity cannot be compared by means of a leak diameter, but requires the consideration of multiple impacting factors (e.g., path length, uniformity).LAY ABSTRACT: Sterility of drug products intended for parenteral administration is a critical quality attribute to ensure patient's safety and is thus a key requirement by health authorities. The absence of microbial contamination must be demonstrated by container closure integrity (CCI) of the container closure system (CCS). Currently, the revised United States Pharmacopeia (USP) General Chapter <1207> provides the most extensive guidance on how CCI should be assessed. Nevertheless, practical considerations on the choice of an appropriate CCIT method, artificial leaks or the choice of an acceptance criteria are lacking and must be addressed by the pharmaceutical manufacturer.This study provides a systematic comparison of four commonly used physical CCIT (pCCIT) methods [Helium (He) leak, vacuum decay, laser-based headspace analysis (HSA) and dye ingress] and four commonly used modes of creating artificial leaks (laser-drilled micro holes, copper wire introduced leaks, and two types of capillary leaks).
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Affiliation(s)
| | | | | | | | | | | | - Anja Matter
- Lonza Drug Product Services, Basel, Switzerland
| | | | | | - Oliver Germershaus
- Institute for Pharma Technology, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
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6
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Loosli V, Germershaus O, Steinberg H, Dreher S, Grauschopf U, Funke S. Methods To Determine the Silicone Oil Layer Thickness in Sprayed-On Siliconized Syringes. PDA J Pharm Sci Technol 2018; 72:278-297. [PMID: 29343617 DOI: 10.5731/pdajpst.2017.007997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The silicone lubricant layer in prefilled syringes has been investigated with regards to siliconization process performance, prefilled syringe functionality, and drug product attributes, such as subvisible particle levels, in several studies in the past. However, adequate methods to characterize the silicone oil layer thickness and distribution are limited, and systematic evaluation is missing. In this study, white light interferometry was evaluated to close this gap in method understanding. White light interferometry demonstrated a good accuracy of 93-99% for MgF2 coated, curved standards covering a thickness range of 115-473 nm. Thickness measurements for sprayed-on siliconized prefilled syringes with different representative silicone oil distribution patterns (homogeneous, pronounced siliconization at flange or needle side, respectively) showed high instrument (0.5%) and analyst precision (4.1%). Different white light interferometry instrument parameters (autofocus, protective shield, syringe barrel dimensions input, type of non-siliconized syringe used as base reference) had no significant impact on the measured average layer thickness. The obtained values from white light interferometry applying a fully developed method (12 radial lines, 50 mm measurement distance, 50 measurements points) were in agreement with orthogonal results from combined white and laser interferometry and 3D-laser scanning microscopy. The investigated syringe batches (lot A and B) exhibited comparable longitudinal silicone oil layer thicknesses ranging from 170-190 nm to 90-100 nm from flange to tip and homogeneously distributed silicone layers over the syringe barrel circumference (110- 135 nm). Empty break-loose (4-4.5 N) and gliding forces (2-2.5 N) were comparably low for both analyzed syringe lots. A silicone oil layer thickness of 100-200 nm was thus sufficient for adequate functionality in this particular study. Filling the syringe with a surrogate solution including short-term exposure and emptying did not significantly influence the silicone oil layer at the investigated silicone level. It thus appears reasonable to use this approach to characterize silicone oil layers in filled syringes over time. The developed method characterizes non-destructively the layer thickness and distribution of silicone oil in empty syringes and provides fast access to reliable results. The gained information can be further used to support optimization of siliconization processes and increase the understanding of syringe functionality.LAY ABSTRACT: Silicone oil layers as lubricant are required to ensure functionality of prefilled syringes. Methods evaluating these layers are limited, and systematic evaluation is missing. The aim of this study was to develop and assess white light interferometry as an analytical method to characterize sprayed-on silicone oil layers in 1 mL prefilled syringes. White light interferometry showed a good accuracy (93-99%) as well as instrument and analyst precision (0.5% and 4.1%, respectively). Different applied instrument parameters had no significant impact on the measured layer thickness. The obtained values from white light interferometry applying a fully developed method concurred with orthogonal results from 3D-laser scanning microscopy and combined white light and laser interferometry. The average layer thicknesses in two investigated syringe lots gradually decreased from 170-190 nm at the flange to 100-90 nm at the needle side. The silicone layers were homogeneously distributed over the syringe barrel circumference (110-135 nm) for both lots. Empty break-loose (4-4.5 N) and gliding forces (2-2.5 N) were comparably low for both analyzed syringe lots. Syringe filling with a surrogate solution, including short-term exposure and emptying, did not significantly affect the silicone oil layer. The developed, non-destructive method provided reliable results to characterize the silicone oil layer thickness and distribution in empty siliconized syringes. This information can be further used to support optimization of siliconization processes and increase understanding of syringe functionality.
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Affiliation(s)
- Viviane Loosli
- Fachhochschule Nordwestschweiz, Hochschule für Life Sciences, Institut für Pharma Technology, 4132 Muttenz, Switzerland; and
| | - Oliver Germershaus
- Fachhochschule Nordwestschweiz, Hochschule für Life Sciences, Institut für Pharma Technology, 4132 Muttenz, Switzerland; and
| | - Henrik Steinberg
- F. Hoffmann-La Roche Ltd, Device Development, PTD Biologics Europe (PTDE-D), 4070 Basel, Switzerland
| | - Sascha Dreher
- F. Hoffmann-La Roche Ltd, Device Development, PTD Biologics Europe (PTDE-D), 4070 Basel, Switzerland
| | - Ulla Grauschopf
- F. Hoffmann-La Roche Ltd, Device Development, PTD Biologics Europe (PTDE-D), 4070 Basel, Switzerland
| | - Stefanie Funke
- F. Hoffmann-La Roche Ltd, Device Development, PTD Biologics Europe (PTDE-D), 4070 Basel, Switzerland
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Qian Y, Li L, Song Y, Dong L, Chen P, Li X, Cai K, Germershaus O, Yang L, Fan Y. Surface modification of nanofibrous matrices via layer-by-layer functionalized silk assembly for mitigating the foreign body reaction. Biomaterials 2018; 164:22-37. [DOI: 10.1016/j.biomaterials.2018.02.038] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 02/13/2018] [Accepted: 02/19/2018] [Indexed: 12/30/2022]
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8
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Nultsch K, Germershaus O. Silk fibroin degumming affects scaffold structure and release of macromolecular drugs. Eur J Pharm Sci 2017; 106:254-261. [DOI: 10.1016/j.ejps.2017.06.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 11/16/2022]
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Kutscher M, Rosenberger M, Schmauss B, Meinel L, Lorenz U, Ohlsen K, Hellmann R, Germershaus O. Surface functionalization allowing repetitive use of optical sensors for real-time detection of antibody-bacteria interaction. J Biophotonics 2016; 9:730-737. [PMID: 26486822 DOI: 10.1002/jbio.201500178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/13/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
In this study, sensor surface functionalization allowing the repetitive use of a sensing device was evaluated for antibody-based detection of living bacteria using an optical planar Bragg grating sensor. To achieve regenerable immobilization of bacteria specific antibodies, the heterobifunctional cross-linker N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) was linked to an aminosilanized sensor surface and subsequently reduced to expose sulfhydryl groups enabling the covalent conjugation of SPDP-activated antibodies via disulfide bonds. The immobilization of a capture antibody specific for Staphylococcus aureus on the sensor surface as well as specific binding of S. aureus could be monitored, highlighting the applicability of optical sensors for the specific detection of large biological structures. Reusability of bacteria saturated sensors was successfully demonstrated by cleaving the antibody along with bound bacteria through reduction of disulfide bonds and subsequent re-functionalization with activated antibody, resulting in comparable sensitivity towards S. aureus.
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Affiliation(s)
- Marika Kutscher
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany
| | - Manuel Rosenberger
- Applied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Wuerzburger Straße 45, 63743, Aschaffenburg, Germany
| | - Bernhard Schmauss
- Institute of Microwaves and Photonics, University of Erlangen-Nuernberg, Cauerstraße 9, 91058, Erlangen, Germany
| | - Lorenz Meinel
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany
| | - Udo Lorenz
- Department of General, Visceral, Vascular and Paediatric Surgery, University Clinic of Wuerzburg, Oberduerrbacher Str. 6, 97080, Wuerzburg, Germany
| | - Knut Ohlsen
- Institute for Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Bau D15, 97080, Wuerzburg, Germany
| | - Ralf Hellmann
- Applied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Wuerzburger Straße 45, 63743, Aschaffenburg, Germany.
| | - Oliver Germershaus
- Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
- Institute for Pharma Technology, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gruendenstrasse 40, 4132, Muttenz, Switzerland.
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Ilko D, Braun A, Germershaus O, Meinel L, Holzgrabe U. Fatty acid composition analysis in polysorbate 80 with high performance liquid chromatography coupled to charged aerosol detection. Eur J Pharm Biopharm 2015; 94:569-74. [DOI: 10.1016/j.ejpb.2014.11.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/09/2014] [Accepted: 11/20/2014] [Indexed: 11/28/2022]
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Braun AC, Ilko D, Merget B, Gieseler H, Germershaus O, Holzgrabe U, Meinel L. Predicting critical micelle concentration and micelle molecular weight of polysorbate 80 using compendial methods. Eur J Pharm Biopharm 2015; 94:559-68. [DOI: 10.1016/j.ejpb.2014.12.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/07/2014] [Accepted: 12/01/2014] [Indexed: 11/24/2022]
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12
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Germershaus O, Nultsch K. Localized, non-viral delivery of nucleic acids: Opportunities, challenges and current strategies. Asian J Pharm Sci 2015. [DOI: 10.1016/j.ajps.2014.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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13
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Kutscher M, Cheow WS, Werner V, Lorenz U, Ohlsen K, Meinel L, Hadinoto K, Germershaus O. Influence of salt type and ionic strength on self-assembly of dextran sulfate-ciprofloxacin nanoplexes. Int J Pharm 2015; 486:21-9. [DOI: 10.1016/j.ijpharm.2015.03.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/09/2015] [Accepted: 03/11/2015] [Indexed: 12/16/2022]
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14
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Li L, Qian Y, Lin C, Li H, Jiang C, Lv Y, Liu W, Cai K, Germershaus O, Yang L. The effect of silk gland sericin protein incorporation into electrospun polycaprolactone nanofibers on in vitro and in vivo characteristics. J Mater Chem B 2015; 3:859-870. [DOI: 10.1039/c4tb00653d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silk middle gland extracted sericin protein based electrospun nanofibrous scaffolds with excellent biocompatibility have been developed for tissue engineering applications.
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Puhl S, Ilko D, Li L, Holzgrabe U, Meinel L, Germershaus O. Protein release from electrospun nonwovens: Improving the release characteristics through rational combination of polyester blend matrices with polidocanol. Int J Pharm 2014; 477:273-81. [DOI: 10.1016/j.ijpharm.2014.10.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/17/2014] [Accepted: 10/18/2014] [Indexed: 11/27/2022]
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16
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Puhl S, Li L, Meinel L, Germershaus O. Controlled Protein Delivery from Electrospun Non-Wovens: Novel Combination of Protein Crystals and a Biodegradable Release Matrix. Mol Pharm 2014; 11:2372-80. [DOI: 10.1021/mp5001026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Sebastian Puhl
- Institute
for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
| | - Linhao Li
- Institute
for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
- Key
Laboratory of Biorheological Science and Technology, Ministry of Education,
College of Bioengineering, Chongqing University, Chongqing 400030, P. R. China
| | - Lorenz Meinel
- Institute
for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
| | - Oliver Germershaus
- Institute
for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, DE-97074 Wuerzburg, Germany
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Zhao H, Heusler E, Jones G, Li L, Werner V, Germershaus O, Ritzer J, Luehmann T, Meinel L. Decoration of silk fibroin by click chemistry for biomedical application. J Struct Biol 2014; 186:420-30. [DOI: 10.1016/j.jsb.2014.02.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 01/26/2023]
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18
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Germershaus O, Werner V, Kutscher M, Meinel L. Deciphering the mechanism of protein interaction with silk fibroin for drug delivery systems. Biomaterials 2014; 35:3427-34. [DOI: 10.1016/j.biomaterials.2013.12.083] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 12/22/2013] [Indexed: 12/24/2022]
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19
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Schnieders J, Gbureck U, Germershaus O, Kratz M, Jones DB, Kissel T. Ex vivo human trabecular bone model for biocompatibility evaluation of calcium phosphate composites modified with spray dried biodegradable microspheres. Adv Healthc Mater 2013; 2:1361-9. [PMID: 23568426 DOI: 10.1002/adhm.201200390] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 01/09/2013] [Indexed: 11/10/2022]
Abstract
Our aim was to study the suitability of the ex-vivo human trabecular bone bioreactor ZetOS to test the biocompatibility of calcium phosphate bone cement composites modified with spray dried, drug loaded microspheres. We hypothesized, that this bone bioreactor could be a promising alternative to in vivo assessment of biocompatibility in living human bone over a defined time period. Composites consisting of tetracycline loaded poly(lactic-co-glycolic acid) microspheres and calcium phosphate bone cement, were inserted into in vitro cultured human femora head trabecular bone and incubated over 30 days at 37°C in the incubation system. Different biocompatibility parameters, such as lactate dehydrogenase activity, alkaline phosphatase release and the expression of relevant cytokines, IL-1β, IL-6, and TNF-α, were measured in the incubation medium. No significant differences in alkaline phosphatase, osteocalcin, and lactate dehydrogenase activity were measured compared to control samples. Tetracycline was released from the microspheres, delivered and incorporated into newly formed bone. In this study we demonstrated that ex vivo biocompatibility testing using human trabecular bone in a bioreactor is a potential alternative to animal experiments since bone metabolism is still maintained in a physiological environment ex vivo.
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Affiliation(s)
- Julia Schnieders
- Department of Pharmaceutical, Technology and Biopharmacy, Philipps-University Marburg, Ketzerbach 63, 35032 Marburg, Germany
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Germershaus O, Schultz I, Lühmann T, Beck-Broichsitter M, Högger P, Meinel L. Insulin-like growth factor-I aerosol formulations for pulmonary delivery. Eur J Pharm Biopharm 2013; 85:61-8. [DOI: 10.1016/j.ejpb.2013.03.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 03/14/2013] [Accepted: 03/15/2013] [Indexed: 10/26/2022]
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21
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Radmanovic N, Serno T, Joerg S, Germershaus O. Understanding the Freezing of Biopharmaceuticals: First-Principle Modeling of the Process and Evaluation of Its Effect on Product Quality. J Pharm Sci 2013; 102:2495-507. [DOI: 10.1002/jps.23642] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/21/2013] [Accepted: 05/30/2013] [Indexed: 01/13/2023]
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22
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Luhmann T, Germershaus O, Groll J, Meinel L. Bone targeting for the treatment of osteoporosis. J Control Release 2011; 161:198-213. [PMID: 22016072 DOI: 10.1016/j.jconrel.2011.10.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 10/01/2011] [Accepted: 10/03/2011] [Indexed: 11/19/2022]
Abstract
Osteoporosis represents a major public health burden especially considering the aging populations worldwide. Drug targeting will be important to better meet these challenges and direct the full therapeutic potential of therapeutics to their intended site of action. This review has been organized in modules, such that scientists working in the field can easily gain specific insight in the field of bone targeting for the drug class they are interested in. We review currently approved and emerging treatment options for osteoporosis and discuss these in light of the benefit these would gain from advanced targeting. In addition, established targeting strategies are reviewed and novel opportunities as well as promising areas are presented along with pharmaceutical strategies how to render novel composites consisting of a drug and a targeting moiety responsive to bone-specific or disease-specific environmental stimuli. Successful implementation of these principles into drug development programs for osteoporosis will substantially contribute to the clinical success of anti-catabolic and anabolic drugs of the future.
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Affiliation(s)
- Tessa Luhmann
- Institute for Pharmacy and Food Chemistry, University of Wurzburg, Am Hubland, DE-97074 Wurzburg, Germany
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Germershaus O, Pickaert G, Konrad J, Krüger U, Kissel T, Haag R. Imidazole and Dimethyl Aminopropyl-Functionalized Hyperbranched Polymers for Nucleic Acid Transfection. Macromol Biosci 2010; 10:1055-62. [DOI: 10.1002/mabi.201000077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Merkel OM, Germershaus O, Wada CK, Tarcha PJ, Merdan T, Kissel T. Integrin ανβ3 Targeted Gene Delivery Using RGD Peptidomimetic Conjugates with Copolymers of PEGylated Poly(ethylene imine). Bioconjug Chem 2009; 20:1270-80. [DOI: 10.1021/bc9001695] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Olivia M. Merkel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Oliver Germershaus
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Carol K. Wada
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Peter J. Tarcha
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Thomas Merdan
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
| | - Thomas Kissel
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany, and Abbott Laboratories Incorporated, 200 Abbott Park Road, Abbot Park, Illinois 60064
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Cai C, Mao S, Germershaus O, Schaper A, Rytting E, Chen D, Kissel T. Influence of morphology and drug distribution on the release process of FITC-dextran-loaded microspheres prepared with different types of PLGA. J Microencapsul 2008; 26:334-45. [DOI: 10.1080/02652040802354707] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Germershaus O, Mao S, Sitterberg J, Bakowsky U, Kissel T. Gene delivery using chitosan, trimethyl chitosan or polyethylenglycol-graft-trimethyl chitosan block copolymers: Establishment of structure–activity relationships in vitro. J Control Release 2008; 125:145-54. [DOI: 10.1016/j.jconrel.2007.10.013] [Citation(s) in RCA: 169] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Revised: 10/10/2007] [Accepted: 10/15/2007] [Indexed: 01/18/2023]
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Neu M, Germershaus O, Behe M, Kissel T. Bioreversibly crosslinked polyplexes of PEI and high molecular weight PEG show extended circulation times in vivo. J Control Release 2007; 124:69-80. [PMID: 17897749 DOI: 10.1016/j.jconrel.2007.08.009] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 08/08/2007] [Accepted: 08/10/2007] [Indexed: 11/23/2022]
Abstract
Copolymers consisting of branched PEI 25 kDa grafted with high molecular weight PEG at a low degree of substitution were successfully synthesized using a simple two-step procedure. The resulting AB-type and ABA-type copolymers were tested for cytotoxicity and DNA condensation and complexation properties. Their polyplexes with plasmid DNA were characterized in terms of DNA size and surface charge, transfection efficiency and blood compatibility. Pharmacokinetic profiles of the complexes containing (32)P-labeled plasmid were assessed before and after surface crosslinking. A set of four copolymers containing one or two PEG 20 kDa or PEG 30 kDa chains was obtained. The cytotoxicity of PEI was strongly reduced after copolymerization. The copolymer polyplexes showed hydrodynamic diameters of less than 200 nm, comparable to PEI 25. Similarly, no reduction in DNA condensation and complexation properties was found. In fact, PEI-PEG(30 k) copolymers exhibited better condensation and complexation properties than PEI 25. The transfection efficiency of copolymer polyplexes was increased 10-fold compared to PEI 25 control and the hemolytic activity was markedly reduced. After intravenous injection into mice, plasmids complexed to PEI-PEG(30 k) copolymers resulted in significantly increased circulation times. After stabilizing the polyplexes with a redox sensitive, biodegradable crosslinker, blood levels of plasmid could be further increased up to 125% compared to PEI. These results demonstrate that polyplexes prepared using a combined strategy of surface crosslinking and PEGylation seem to provide promising properties as stable, long circulating vectors.
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Affiliation(s)
- Michael Neu
- Department of Pharmaceutics and Biopharmacy, Philipps Universität, 35037 Marburg, Germany
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Germershaus O, Neu M, Behe M, Kissel T. HER2 targeted polyplexes: the effect of polyplex composition and conjugation chemistry on in vitro and in vivo characteristics. Bioconjug Chem 2007; 19:244-53. [PMID: 18034452 DOI: 10.1021/bc700311n] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Knowledge of the influence of targeting ligands on pharmacokinetics and biodistribution of polymeric nonviral vectors is presently limited. We investigated the properties of three structurally different conjugates of polyethylenglycol-modified polyethylenimine coupled to the HER2 specific antibody Trastuzumab. Unlike polyethylenimine, conjugates formed small (100-230 nm) DNA polyplexes with zeta-potentials of +/- 2 mV at a broad range of N/P ratios. Stability as assessed by heparin displacement was slightly improved compared to unmodified copolymers. Erythrocyte aggregation and hemolysis were strongly reduced with conjugates. Conjugate polyplexes showed significant differences in specificity and transfection efficiency in vitro. These could be attributed to differences in cell binding and uptake assessed by flow cytometry. Pharmacokinetics of conjugates in mice revealed significant improvements over free plasmid DNA and polyethylenimine. Area under the plasma level-time curve of conjugates was increased up to 48% or 114% compared to that of polyethylenimine or free plasmid DNA, respectively. Deposition of conjugate polyplexes in lung and spleen was significantly reduced compared to that of polyethylenimine. Differences could be attributed to antibody conjugation since no significant differences in pharmacokinetics and biodistribution were found between conjugates. These findings demonstrate that conjugated antibodies not only confer active targeting but also significantly improve in vivo properties of polyplexes.
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Affiliation(s)
- Oliver Germershaus
- Department of Pharmaceutics and Biopharmacy, Philipps Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany
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29
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Mao S, Neu M, Germershaus O, Merkel O, Sitterberg J, Bakowsky U, Kissel T. Influence of polyethylene glycol chain length on the physicochemical and biological properties of poly(ethylene imine)-graft-poly(ethylene glycol) block copolymer/SiRNA polyplexes. Bioconjug Chem 2007; 17:1209-18. [PMID: 16984130 DOI: 10.1021/bc060129j] [Citation(s) in RCA: 245] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polyplexes between siRNA and poly(ethylene imine) (PEI) derivatives are promising nonviral carriers for siRNA. The polyplex stability is of critical importance for efficient siRNA delivery to the cytoplasm. Here, we investigate the effect of PEGylation at a constant ratio ( approximately 50%) on the biophysical properties of the polyplexes. Particle size, zeta potential, and stability against heparin as well as RNase digestion and reporter gene knockdown under in vitro conditions of different siRNA polyplexes were characterized. Stability and size of siRNA polyplexes were clearly influenced by PEI-PEG structure, and high degrees of substitution such as PEI(25k)-g-PEG(550)(30) resulted in large (300-400 nm), diffuse complexes (AFM) which showed condensation behavior only at high N/P ratios. All other polyplexes and the PEI control showed similar sizes (150 nm) and compact structures in AFM, with complete condensation reached at N/P ratio of 3. Stability of siRNA polyplexes against heparin displacement and RNase digestion could be modified by PEGylation. Protection against RNase digestion was highest for PEI(25k)-g-PEG(5k)(4) and PEI(25k)-g-PEG(20k)(1), while siRNA/PEI provided insufficient protection. In knockdown experiments using NIH/3T3 fibroblasts stably expressing beta-galactosidase, it was shown that PEG chain length had a significant influence on biological activity of siRNA. Polyplexes with siRNA containing PEI(25k)-g-PEG(5k)(4) and PEI(25k)-g-PEG(20k)(1) yielded similar efficiencies of ca. 70% knockdown as lipofectamine controls. Confocal microscopy demonstrated enhanced cellular uptake of siRNA into cytosol by polyplexes formation with PEI copolymers. In conclusion, both the chain length and graft density of PEG were found to strongly influence siRNA condensation and stability and hence affect the knockdown efficiency of PEI-PEG/siRNA polyplexes.
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Affiliation(s)
- Shirui Mao
- Department of Pharmaceutics and Biopharmacy, Philipps Universität Marburg, Ketzerbach 63, 35032 Marburg, Germany
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Mao S, Xu J, Cai C, Germershaus O, Schaper A, Kissel T. Effect of WOW process parameters on morphology and burst release of FITC-dextran loaded PLGA microspheres. Int J Pharm 2007; 334:137-48. [PMID: 17196348 DOI: 10.1016/j.ijpharm.2006.10.036] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 10/23/2006] [Indexed: 11/24/2022]
Abstract
Using fluorescein isothiocyanate labeled dextran (FITC-dextran 40, FD40) as a hydrophilic model compound, microspheres were prepared by a WOW double emulsion technique. Influence of process parameters on microsphere morphology and burst release of FD40 from PLGA microspheres was studied. Internal morphology of microspheres was investigated by stereological method via cryo-cutting technique and scanning electron microscopy (SEM). Drug distribution in microspheres was observed with confocal laser scanning microscopy (CLSM). Polymer nature (RG503 and RG503H) had significant influence on the micro-morphology of microspheres. Increase in continuous water phase volume (W2) led to increased surface porosity but decreased internal porosity. By increasing PVA concentration in the continuous phase from 0.1 to 1%, particle size changed marginally but burst release decreased from 12.2 to 5.9%. Internal porosity of microspheres decreased considerably with increasing polymer concentration. Increase in homogenization speed during the primary emulsion preparation led to decreased internal porosity. Burst release decreased with increasing drug loading but increased with drug molecular weight. Drug distribution in microspheres depended on preparation method. The porosity of microspheres decreased with time in the diffusion stage, but internal morphology had no influence on the release behavior in the bioerosion stage. In summary, surface porosity and internal morphology play a significant role in the release of hydrophilic macromolecules from biodegradable microspheres in the initial release phase characterized by pore diffusion.
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Affiliation(s)
- Shirui Mao
- Department of Pharmaceutics and Biopharmacy, Philipps Universität Marburg, Ketzerbach 63, D-35032 Marburg, Germany
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Neu M, Germershaus O, Mao S, Voigt KH, Behe M, Kissel T. Crosslinked nanocarriers based upon poly(ethylene imine) for systemic plasmid delivery: In vitro characterization and in vivo studies in mice. J Control Release 2007; 118:370-80. [PMID: 17316863 DOI: 10.1016/j.jconrel.2007.01.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 01/11/2007] [Accepted: 01/15/2007] [Indexed: 10/23/2022]
Abstract
Crosslinked poly(ethylene imine) (PEI) polyplexes for intracellular DNA release were generated using a low molecular weight crosslinking reagent, Dithiobis(succinimidyl propionate) (DSP). Disulfide bonds of the crosslinked polyplexes were susceptible to intracellular redox conditions and DNA release was observed using an ethidium bromide exclusion assay and dynamic light scattering. Transfection experiments were performed to elucidate the effect of extra- and intracellular redox conditions. Pharmacokinetics and organ accumulation of uncrosslinked and crosslinked polyplexes were compared and gene expression patterns were measured in mice 24 h after intravenous injection. Crosslinked PEI and plasmid DNA formed stable polyplexes in a size range of 100-300 nm, with zeta potentials between +16.4 and +26.1 mV. DNA release occurred after cleavage of the disulfide bonds. Cell culture experiments under reducing conditions as well as with glutathione loaded cells confirmed the proposed intracellular activation. A significant influence of the intracellular glutathione status on the transfection efficiency was observed. Pharmacokinetic profiles of crosslinked PEI/DNA polyplexes in mice after intravenous administration showed higher blood levels for crosslinked polyplexes. These polyplexes accumulated mainly in the liver and the lungs. In vivo transfection data revealed significantly reduced (unwanted) lung transfection while liver transfection predominated. These studies suggest that crosslinked polyplexes are more stable in circulation and retain their transfection efficiency after intravenous administration.
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Affiliation(s)
- Michael Neu
- Department of Pharmaceutics and Biopharmacy, Philipps Universität, Ketzerbach 63, Marburg, Germany
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Germershaus O, Merdan T, Bakowsky U, Behe M, Kissel T. Trastuzumab−Polyethylenimine−Polyethylene Glycol Conjugates for Targeting Her2-Expressing Tumors. Bioconjug Chem 2006; 17:1190-9. [PMID: 16984128 DOI: 10.1021/bc0601119] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we describe the synthesis and characterization of a conjugate consisting of poly(ethylene glycol 2,000 Da)(10)-graft-poly(ethylene imine 25 kDa) (PEG-PEI) covalently coupled to Trastuzumab (Herceptin) via N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) for specific gene delivery to Her2-expressing cell lines. The efficiency of DNA condensation was studied using an ethidium bromide exclusion assay and demonstrated negligible differences compared to PEG-PEI. Conjugate complex sizes were determined by dynamic light scattering to be in the range 130-180 nm. zeta potentials at different N/P ratios were close to neutral. Flow cytometry and confocal microscopy revealed efficient binding and uptake of Trastuzumab-PEI-PEG complexes using Her2-positive SK-BR-3 cells. In contrast, binding and uptake into Her2-negative OVCAR-3 cells was negligible. In good correlation with these findings, reporter gene expression using targeted complexes in SK-BR-3 cells was up to sevenfold higher than that of unmodified PEG-PEI complexes. With the use OVCAR-3 cells, no significant difference in expression efficiencies could be observed between conjugate and PEG-PEI complexes. Inhibition experiments with free Trastuzumab showed a significant decrease in reporter gene expression using SK-BR-3 cells but no decrease using OVCAR-3 cells, strongly supporting a specific Her2-receptor-mediated uptake mechanism. Our results suggest that Trastuzumab-PEI-PEG might be a promising new bioconjugate for targeted gene transfer to Her2-positive tumor cells in vivo.
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Affiliation(s)
- Oliver Germershaus
- Department of Pharmaceutics and Biopharmacy, Philipps University Marburg, Ketzerbach 63, 35032 Marburg, Germany
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Mao S, Germershaus O, Fischer D, Linn T, Schnepf R, Kissel T. Uptake and Transport of PEG-Graft-Trimethyl-Chitosan Copolymer–Insulin Nanocomplexes by Epithelial Cells. Pharm Res 2005; 22:2058-68. [PMID: 16170693 DOI: 10.1007/s11095-005-8175-y] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2005] [Accepted: 08/16/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE The effect of chitosan and polyethylene glycol (PEG)ylated trimethyl chitosan copolymer structure on the uptake and transport of insulin nanocomplexes was evaluated and transport mechanisms were investigated. METHODS Insulin nanocomplexes were prepared from chitosan and its copolymers by self-assembly. Complex uptake in Caco-2 cells was quantified by measuring the cell-associated fluorescence and cellular localization was visualized by confocal laser scanning microscopy (CLSM) using tetra-methyl-rhodamine isothiocyanate-labeled insulin. The transport of selected insulin complexes through Caco-2 monolayers was then investigated and compared with in vivo uptake by nasal epithelium in diabetic rats. RESULTS All complexes were 200-400 nm in diameter, positively charged, and displayed an insulin loading efficiency of approximately 90%. In vitro release of insulin from the complexes was dependent on the medium pH. Insulin uptake was enhanced by nanocomplex formation, and was dependent on incubation time, temperature, and concentration. Complex uptake in Caco-2 cells was inhibited by 25.2 +/- 1.3%, 13.0 +/- 1.0%, and 16.6 +/- 0.7% in the presence of cytochalasin D, sodium azide, and 2,4-dinitrophenol, respectively. The uptake mechanism was assumed to be adsorptive endocytosis. Additionally, cell uptake efficiency was shown to be influenced by a combination of polymer molecular weight, viscosity, and positive charge density. However, none of the nanocomplexes displayed improved transport properties when compared to insulin transport data after 2 h incubation with Caco-2 monolayers. This result was further confirmed with animal experiments. CONCLUSIONS Small, stable insulin nanocomplexes were formed using PEGylated trimethyl chitosan copolymers, which significantly enhanced the uptake of insulin in Caco-2 cells by adsorptive endocytosis. However, nanocomplexation did not seem to enhance transcellular insulin transport across cell monolayers, which is in line with animal data in rats. This implies that PEGylated trimethyl chitosan complexes with insulin need further optimization and the Caco-2 cell line is a predictable in vitro cell culture model for drug absorption.
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Affiliation(s)
- Shirui Mao
- Department of Pharmaceutics and Biopharmacy, Philipps-University of Marburg, Ketzerbach 63, D-35032, Marburg, Germany
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Abstract
The iodine value (iodine number) is an important analytical characteristic of fats and oils. Leading pharmacopeias determine it using iodine monobromide (Hanus method). We used methyl oleate as a simple analog of unsaturated triacylglycerols to identify the products. After performing the reaction in deuterated solvents under pharmacopeial conditions, NMR spectroscopy revealed the presence of the 9, 10-diiodo, 9, 10-dibromo, and 9, 10-bromoiodo adducts, leaving no educt olefin. The prescribed subsequent addition of potassium iodide led to the formation of methyl 9, 10-diiodo and bromoiodo stearate in equal amounts.
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Affiliation(s)
- Peter Imming
- Institut für Pharmazeutische Chemie, Philipps-Universität, Marburg, Germany.
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