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Kromer APE, Sieber-Schäfer F, Farfan Benito J, Merkel OM. Design of Experiments Grants Mechanistic Insights into the Synthesis of Spermine-Containing PBAE Copolymers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:37545-37554. [PMID: 38985802 DOI: 10.1021/acsami.4c06079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
Successful therapeutic delivery of siRNA with polymeric nanoparticles seems to be a promising but not vastly understood and complicated goal to achieve. Despite years of research, no polymer-based delivery system has been approved for clinical use. Polymers, as a delivery system, exhibit considerable complexity and variability, making their consistent production a challenging endeavor. However, a better understanding of the polymerization process of polymer excipients may improve the reproducibility and material quality for more efficient use in drug products. Here, we present a combination of Design of Experiment and Python-scripted data science to establish a prediction model, from which important parameters can be extracted that influence the synthesis results of polybeta-amino esters (PBAEs), a common type of polymer used preclinically for nucleic acid delivery. We synthesized a library of 27 polymers, each one at different temperatures with different reaction times and educt ratios using an orthogonal central composite (CCO-) design. This design allowed a detailed characterization of factor importance and interactions using a very limited number of experiments. We characterized the polymers by analyzing the resulting composition by 1H-NMR and the size distribution by GPC measurements. To further understand the complex mechanism of block polymerization in a one-pot synthesis, we developed a Python script that helps us to understand possible step-growth steps. We successfully developed and validated a predictive response surface and gathered a deeper understanding of the synthesis of polyspermine-based amphiphilic PBAEs.
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Affiliation(s)
- Adrian P E Kromer
- Pharmaceutical Technology and Biopharmaceutics, Department of Pharmacy, Ludwig-Maximilians-University München, Munich 81377, Germany
| | - Felix Sieber-Schäfer
- Pharmaceutical Technology and Biopharmaceutics, Department of Pharmacy, Ludwig-Maximilians-University München, Munich 81377, Germany
| | - Johan Farfan Benito
- Pharmaceutical Technology and Biopharmaceutics, Department of Pharmacy, Ludwig-Maximilians-University München, Munich 81377, Germany
- Université Paris Cité, Paris 75015, France
| | - Olivia M Merkel
- Pharmaceutical Technology and Biopharmaceutics, Department of Pharmacy, Ludwig-Maximilians-University München, Munich 81377, Germany
- Center for NanoScience Munich (CeNS), Munich 81377, Germany
- Cluster for Nucleic Acid Therapeutics Munich (CNATM), Munich 81377, Germany
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Jin Y, Wang X, Kromer AP, Müller JT, Zimmermann C, Xu Z, Hartschuh A, Adams F, Merkel OM. Role of Hydrophobic Modification in Spermine-Based Poly(β-amino ester)s for siRNA Delivery and Their Spray-Dried Powders for Inhalation and Improved Storage. Biomacromolecules 2024; 25:4177-4191. [PMID: 38866384 PMCID: PMC11238323 DOI: 10.1021/acs.biomac.4c00283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 06/14/2024]
Abstract
After RNAi was first discovered over 20 years ago, siRNA-based therapeutics are finally becoming reality. However, the delivery of siRNA has remained a challenge. In our previous research, we found that spermine-based poly(β-amino ester)s are very promising for siRNA delivery. However, the role of hydrophobic modification in siRNA delivery of spermine-based poly(β-amino ester)s is not fully understood yet. In the current work, we synthesized spermine-based poly(β-amino ester)s with different percentages of oleylamine side chains, named P(SpOABAE). The chemical structures of the polymers were characterized by 1H NMR. The polymers showed efficient siRNA encapsulation determined by SYBR Gold assays. The hydrodynamic diameters of the P(SpOABAE) polyplexes from charge ratio N/P 1 to 20 were 30-100 nm except for aggregation phenomena observed at N/P 3. Morphology of the polyplexes was visualized by atomic force microscopy, and cellular uptake was determined by flow cytometry in H1299 cells, where all the polyplexes showed significantly higher cellular uptake than hyperbranched polyethylenimine (25 kDa). The most hydrophobic P(SpOABAE) polyplexes were able to achieve more than 90% GFP knockdown in H1299/eGFP cells. The fact that gene silencing efficacy increased with hydrophobicity but cellular uptake was affected by both charge and hydrophobic interactions highlights the importance of endosomal escape. For pulmonary administration and improved storage stability, the polyplexes were spray-dried. Results confirmed the maintained siRNA activity after storage for 3 months at room temperature, indicating potential for dry powder inhalation.
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Affiliation(s)
- Yao Jin
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Xiaoxuan Wang
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Adrian P.E. Kromer
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Joschka T. Müller
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Christoph Zimmermann
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Zehua Xu
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstr.
5-13, 81377 Munich, Germany
| | - Achim Hartschuh
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstr.
5-13, 81377 Munich, Germany
- Center
for Nanoscience (CeNS), Ludwig-Maximilians-Universität
München, 80799 München, Germany
| | - Friederike Adams
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
| | - Olivia M. Merkel
- Department
of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
- Center
for Nanoscience (CeNS), Ludwig-Maximilians-Universität
München, 80799 München, Germany
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Adams F, Zimmermann CM, Baldassi D, Pehl TM, Weingarten P, Kachel I, Kränzlein M, Jürgens DC, Braubach P, Alexopoulos I, Wygrecka M, Merkel OM. Pulmonary siRNA Delivery with Sophisticated Amphiphilic Poly(Spermine Acrylamides) for the Treatment of Lung Fibrosis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2308775. [PMID: 38126895 DOI: 10.1002/smll.202308775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/16/2023] [Indexed: 12/23/2023]
Abstract
RNA interference (RNAi) is an efficient strategy to post-transcriptionally silence gene expression. While all siRNA drugs on the market target the liver, the lung offers a variety of currently undruggable targets, which can potentially be treated with RNA therapeutics. To achieve this goal, the synthesis of poly(spermine acrylamides) (P(SpAA) is reported herein. Polymers are prepared via polymerization of N-acryloxysuccinimide (NAS) and afterward this active ester is converted into spermine-based pendant groups. Copolymerizations with decylacrylamide are employed to increase the hydrophobicity of the polymers. After deprotection, polymers show excellent siRNA encapsulation to obtain perfectly sized polyplexes at very low polymer/RNA ratios. In vitro 2D and 3D cell culture, ex vivo and in vivo experiments reveal superior properties of amphiphilic spermine-copolymers with respect to delivery of siRNA to lung cells in comparison to commonly used lipid-based transfection agents. In line with the in vitro results, siRNA delivery to human lung explants confirm more efficient gene silencing of protease-activated receptor 2 (PAR2), a G protein-coupled receptor involved in fibrosis. This study reveals the importance of the balance between efficient polyplex formation, cellular uptake, gene knockdown, and toxicity for efficient siRNA delivery in vitro, in vivo, and in fibrotic human lung tissue ex vivo.
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Affiliation(s)
- Friederike Adams
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
- Institute of Polymer Chemistry, Chair of Macromolecular Materials and Fiber Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
- Center for Ophthalmology, University Eye Hospital Tübingen, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany
| | - Christoph M Zimmermann
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Domizia Baldassi
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Thomas M Pehl
- WACKER-Chair of Macromolecular Chemistry, Catalysis Research Center, Department of Chemistry, Technical University Munich, Lichtenbergstr. 4, 85748, Garching bei München, Germany
| | - Philipp Weingarten
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Iris Kachel
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Moritz Kränzlein
- WACKER-Chair of Macromolecular Chemistry, Catalysis Research Center, Department of Chemistry, Technical University Munich, Lichtenbergstr. 4, 85748, Garching bei München, Germany
| | - David C Jürgens
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
| | - Peter Braubach
- Institute for Pathology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hanover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH) Research Network, Member of the German Center for Lung Research (DZL), Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hanover, Germany
| | - Ioannis Alexopoulos
- Center for Infections and Genomics of the Lung (CIGL), Justus Liebig University Giessen, German Center for Lung Research, Aulweg 132, 35392, Gießen, Germany
- Multiscale Imaging Platform, Institute for Lung Health, German Center for Lung Research, Aulweg 132, 35392, Giessen, Germany
| | - Malgorzata Wygrecka
- Center for Infections and Genomics of the Lung (CIGL), Justus Liebig University Giessen, German Center for Lung Research, Aulweg 132, 35392, Gießen, Germany
| | - Olivia M Merkel
- Pharmaceutical Technology and Biopharmaceutics, Department Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstr. 5-13, 81377, Munich, Germany
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