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Nayan MU, Panja S, Sultana A, Zaman LA, Vora LK, Sillman B, Gendelman HE, Edagwa B. Polymer Delivery Systems for Long-Acting Antiretroviral Drugs. Pharmaceutics 2024; 16:183. [PMID: 38399244 PMCID: PMC10892262 DOI: 10.3390/pharmaceutics16020183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The success of long-acting (LA) drug delivery systems (DDSs) is linked to their biocompatible polymers. These are used for extended therapeutic release. For treatment or prevention of human immune deficiency virus type one (HIV-1) infection, LA DDSs hold promise for improved regimen adherence and reduced toxicities. Current examples include Cabenuva, Apretude, and Sunlenca. Each is safe and effective. Alternative promising DDSs include implants, prodrugs, vaginal rings, and microarray patches. Each can further meet patients' needs. We posit that the physicochemical properties of the formulation chemical design can optimize drug release profiles. We posit that the strategic design of LA DDS polymers will further improve controlled drug release to simplify dosing schedules and improve regimen adherence.
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Affiliation(s)
- Mohammad Ullah Nayan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Sudipta Panja
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Ashrafi Sultana
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Lubaba A. Zaman
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Lalitkumar K. Vora
- School of Pharmacy, Queen’s University Belfast, Medical Biology Centre, Belfast BT9 7BL, UK;
| | - Brady Sillman
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Howard E. Gendelman
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
| | - Benson Edagwa
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5880, USA; (M.U.N.); (S.P.); (A.S.); (L.A.Z.); (B.S.)
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2
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Wu L, Wang Y, Zhao X, Mao H, Gu Z. Investigating the Biodegradation Mechanism of Poly(trimethylene carbonate): Macrophage-Mediated Erosion by Secreting Lipase. Biomacromolecules 2023; 24:921-928. [PMID: 36644840 DOI: 10.1021/acs.biomac.2c01350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Poly(trimethylene carbonate) (PTMC), as one of the representatives of biodegradable aliphatic polycarbonates, has been found to degrade in vivo via surface erosion. This unique degradation behavior and the resulting nonacidic products make it more competitive with aliphatic polyesters (e.g., polylactide) in clinical practice. However, this surface degradation mechanism is complicated and not fully understood to date despite the findings that several reactive oxygen species and enzymes can specifically degrade PTMC in vitro. Herein, the biodegradation mechanism of PTMC was investigated by using possible degradation factors, distinct cell lines, and the inhibitors of these factors. The results demonstrate that PTMC undergoes a specific macrophage-mediated erosion. Macrophages tend to fuse into giant cells and elicit a typical inflammatory response by releasing proinflammatory cytokines. In addition, macrophages are suggested to primarily secrete enzymes (lipase specifically) to erode the PTMC bulk extracellularly as inhibiting their activity effectively prevented this eroding process. The clarification of the biodegradation mechanism in this work suggests that the degradation of PTMC highly depends on the foreign body response. Thus, it reminds the researchers to consider the effect of the microenvironment on the degradation and drug release of PTMC-based implantation devices and localized drug delivery systems.
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Affiliation(s)
- Lihuang Wu
- Research Institute for Biomaterials, Tech Institute for Advanced Materials, College of Materials Science and Engineering, Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Suqian Advanced Materials Industry Technology Innovation Center, Nanjing Tech University, Nanjing 211816, China
| | - Yuqi Wang
- Research Institute for Biomaterials, Tech Institute for Advanced Materials, College of Materials Science and Engineering, Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Suqian Advanced Materials Industry Technology Innovation Center, Nanjing Tech University, Nanjing 211816, China
| | - Xinyue Zhao
- Research Institute for Biomaterials, Tech Institute for Advanced Materials, College of Materials Science and Engineering, Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Suqian Advanced Materials Industry Technology Innovation Center, Nanjing Tech University, Nanjing 211816, China
| | - Hongli Mao
- Research Institute for Biomaterials, Tech Institute for Advanced Materials, College of Materials Science and Engineering, Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Suqian Advanced Materials Industry Technology Innovation Center, Nanjing Tech University, Nanjing 211816, China.,NJTech-BARTY Joint Research Center for Innovative Medical Technology, Nanjing Tech University, Nanjing 210000, China
| | - Zhongwei Gu
- Research Institute for Biomaterials, Tech Institute for Advanced Materials, College of Materials Science and Engineering, Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Suqian Advanced Materials Industry Technology Innovation Center, Nanjing Tech University, Nanjing 211816, China.,NJTech-BARTY Joint Research Center for Innovative Medical Technology, Nanjing Tech University, Nanjing 210000, China
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Amsden B. In Vivo Degradation Mechanisms of Aliphatic Polycarbonates and Functionalized Aliphatic Polycarbonates. Macromol Biosci 2021; 21:e2100085. [PMID: 33893715 DOI: 10.1002/mabi.202100085] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/29/2021] [Indexed: 11/06/2022]
Abstract
Aliphatic polycarbonates (APCs) have been studied for decades but have not been as utilized as aliphatic polyesters in biomaterial applications such as drug delivery and tissue engineering. With the recognition that functionalized aliphatic polymers can be readily synthesized, increased attention is being paid to these materials. A frequently provided reason for utilizing these polymers is that they degrade to form diols and carbon dioxide. However, depending on the structure and molecular weight of the APC, degradation may not occur. In this review, the mechanisms by which APCs and functionalized APCs have been found to degrade in vivo are examined with the objective of providing guidance in the continued development of these polymers as biomaterials.
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Affiliation(s)
- Brian Amsden
- Department of Chemical Engineering, Queen's University, Kingston, K7L 3N6, Canada
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Cagnon ME, Curia S, Serindoux J, Cros JM, Ng F, Lopez-Noriega A. Poly(ethylene glycol)- b-poly(1,3-trimethylene carbonate) Copolymers for the Formulation of In Situ Forming Depot Long-Acting Injectables. Pharmaceutics 2021; 13:pharmaceutics13050605. [PMID: 33922166 PMCID: PMC8146374 DOI: 10.3390/pharmaceutics13050605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/02/2021] [Accepted: 04/19/2021] [Indexed: 11/20/2022] Open
Abstract
This article describes the utilization of (methoxy)poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate) ((m)PEG–PTMC) diblock and triblock copolymers for the formulation of in situ forming depot long-acting injectables by solvent exchange. The results shown in this manuscript demonstrate that it is possible to achieve long-term drug deliveries from suspension formulations prepared with these copolymers, with release durations up to several months in vitro. The utilization of copolymers with different PEG and PTMC molecular weights affords to modulate the release profile and duration. A pharmacokinetic study in rats with meloxicam confirmed the feasibility of achieving at least 28 days of sustained delivery by using this technology while showing good local tolerability in the subcutaneous environment. The characterization of the depots at the end of the in vivo study suggests that the rapid phase exchange upon administration and the surface erosion of the resulting depots are driving the delivery kinetics from suspension formulations. Due to the widely accepted utilization of meloxicam as an analgesic drug for animal care, the results shown in this article are of special interest for the development of veterinary products aiming at a very long-term sustained delivery of this therapeutic molecule.
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Mohajeri S, Amsden BG. In Vivo Degradation Mechanism and Biocompatibility of a Biodegradable Aliphatic Polycarbonate: Poly(Trimethylene Carbonate- co-5-Hydroxy Trimethylene Carbonate). ACS APPLIED BIO MATERIALS 2021; 4:3686-3696. [PMID: 35014453 DOI: 10.1021/acsabm.1c00160] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A recently developed viscous liquid aliphatic polycarbonate, poly(trimethylene carbonate-co-5-hydroxy trimethylene carbonate), has advantageous properties for the delivery of acid-sensitive drugs such as proteins and peptides. This copolymer degrades in vitro via an alkaline-catalyzed intramolecular cyclization reaction yielding oligo (trimethylene carbonate), glycerol, and carbon dioxide, but its in vivo degradation mechanisms are presently unknown. The in vivo degradation mechanism and tissue response to this copolymer were investigated following subcutaneous implantation in Wistar rats. The molecular weight and composition of the copolymer varied in the same manner following subcutaneous implantation as observed in vitro. These findings suggest that the copolymer also degraded in vivo principally via intramolecular cyclization. The tissue response in terms of the inflammatory zone cell density, fibrous capsule thickness, and macrophage response was intermediate to that of two clinically used biodegradable sutures, Vicryl and Monocryl, indicating that the copolymer can be considered biotolerable. Collectively, the data show that further development of this copolymer as a drug delivery material is warranted.
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Affiliation(s)
- Sara Mohajeri
- Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada.,Human Mobility Research Centre, Kingston General Hospital, Kingston, Ontario K7L 2V7, Canada
| | - Brian G Amsden
- Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada.,Human Mobility Research Centre, Kingston General Hospital, Kingston, Ontario K7L 2V7, Canada
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6
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Polymer heatproofing mechanism of lignin extracted by simultaneous enzymatic saccharification and comminution. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Antioxidant-mediated control of degradation and drug release from surface-eroding poly(ethylene carbonate). Acta Biomater 2020; 113:210-216. [PMID: 32623099 DOI: 10.1016/j.actbio.2020.06.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 11/22/2022]
Abstract
Surface-eroding polymers are of significant interest for various applications in the field of controlled drug delivery. Poly(ethylene carbonate), as an example, offers little control over the rate of degradation and, thus, drug release, which usually conflicts with the requirements for long-acting medications. Here, we challenged an option to decelerate the degradation of poly(ethylene carbonate) in vitro and in vivo. When polymer films loaded with distinct antioxidants (vitamins) along with the model drugs leuprorelin and risperidone were incubated in superoxide radical solution and phagocyte culture, the mass loss and drug release from the delivery vehicle was a function of the type and dose of the utilized antioxidant. Once the polymer surface was "attacked" by reactive oxygen species, the antioxidants were released on demand quenching the polymer-degrading radicals. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended "life-time" of one month or longer, which is difficult to achieve for poly(ethylene carbonate) in the absence of antioxidants. A comparable degradation and drug release behavior was observed when antioxidant-loaded poly(ethylene carbonate) films were implanted in rats. Furthermore, linear correlations were obtained between the mass loss of the polymer films and the released fraction of drug (with slopes close to 1), a clear indication for the surface erosion of poly(ethylene carbonate) in vitro and in vivo. Overall, an addition of antioxidants to poly(ethylene carbonate)-based controlled drug delivery vehicles represents a reasonable approach to modify the performance of long-acting medications, especially when a "life time" of weeks to months needs to be achieved. STATEMENT OF SIGNIFICANCE: Surface-eroding poly(ethylene carbonate) (PEC) is of significant interest for long-acting injectable formulations. However, PEC offers only little control over the rate of degradation and, thus, drug release kinetics. We describe an option to decelerate the degradation rate of PEC in vitro and in vivo. When polymer films loaded with distinct antioxidants along with model drugs were incubated in superoxide radical solution, phagocyte culture and implanted in rats, their mass loss and drug release was a function of the type and dose of the utilized antioxidant. Accordingly, specific combinations of polymer and radical scavengers resulted in controlled release medications with an extended "life-time" of one month or longer, which is difficult to achieve for PEC in the absence of antioxidants.
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8
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Beck-Broichsitter M. Comparative in vitro degradation of surface-eroding poly(alkylene carbonate)s. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Augustine D, Hadjichristidis N, Gnanou Y, Feng X. Hydrophilic Stars, Amphiphilic Star Block Copolymers, and Miktoarm Stars with Degradable Polycarbonate Cores. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b02658] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Dhanya Augustine
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Nikos Hadjichristidis
- KAUST Catalysis Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Yves Gnanou
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Xiaoshuang Feng
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
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10
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Mechanical and degradation properties in alkaline solution of poly(ethylene carbonate)/poly(lactic acid) blends. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.01.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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12
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13
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Shikinaka K, Nakamura M, Navarro RR, Otsuka Y. Plant-Based Antioxidant Nanoparticles without Biological Toxicity. ChemistryOpen 2018; 7:709-712. [PMID: 30250777 PMCID: PMC6144725 DOI: 10.1002/open.201800157] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/22/2018] [Indexed: 12/31/2022] Open
Abstract
Here, we present a function to derive non‐deteriorated nanoparticulated lignin as an antioxidant without biological toxicity that is supplied through the simultaneous enzymatic saccharification and comminution of plants. The lignin exhibits an oxygen radical absorption capacity, even in its macromolecular nature. The non‐deteriorated lignin nanoparticles never inhibit the biological activity of living things, despite their antioxidant nature. The oxygen radical absorption capacity of lignin is dependent on its botanical origin and monomeric structure. A stable organic radical in lignin is responsible for the antioxidant nature of non‐deteriorated lignin. The organic radical of non‐deteriorated lignin, which yields a distinct signal on electron spin resonance spectra, serves as a spin trap reagent that detects the emergence of short lifespan radicals as the change of radical concentration of the lignin. The presented discovery of non‐deteriorated lignin will induce not only the industrial utilization of plant biomass polymers in pharmaceuticals and reagents, but also advance our scientific understanding of the antioxidant function of native lignin.
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Affiliation(s)
- Kazuhiro Shikinaka
- Research Institute for Chemical Process Technology National Institute of Advanced Industrial Science and Technology, Nigatake 4-2-1, Miyagino-ku Sendai 983-8551 Japan
| | - Masaya Nakamura
- Forestry and Forest Products Research Institute Matsunosato, 1 Tsukuba 305-8687 Japan
| | - Ronald R Navarro
- Forestry and Forest Products Research Institute Matsunosato, 1 Tsukuba 305-8687 Japan
| | - Yuichiro Otsuka
- Forestry and Forest Products Research Institute Matsunosato, 1 Tsukuba 305-8687 Japan
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Priemel PA, Wang Y, Bohr A, Water JJ, Yang M, Mørck Nielsen H. Poly(ethylene carbonate)-containing polylactic acid microparticles with rifampicin improve drug delivery to macrophages. J Pharm Pharmacol 2018; 70:1009-1021. [DOI: 10.1111/jphp.12937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 04/16/2018] [Indexed: 12/21/2022]
Abstract
Abstract
Objective
Pulmonary delivery of antibiotics will decrease the required dose for efficient treatment of lung infections and reduce systemic side effects of the drug. The objective was to evaluate the applicability of poly(ethylene carbonate) (PEC) for the preparation of inhalable, antibiotic-containing particles.
Methods
Rifampicin (RF)-loaded microparticles were prepared by electrospraying a carrier matrix of polylactic acid (PLA) with 0%, 5% and 10% PEC.
Key findings
Prepared particles had an aerodynamic diameter between 4 and 5 μm. Within 60 min, PEC-containing particles released 35–45% of RF, whereas PLA particles released only 15% of RF. Irrespective of particle composition, uptake of RF by macrophages was improved to 40–60% when formulated in microparticles compared to 0.4% for RF in solution, and intracellular localisation of particles was confirmed using confocal microscopy. Effect on macrophage and alveolar cell viability was similar for all particles whereas the minimal inhibitory concentrations against Pseudomonas aeruginosa and Escherichia coli for RF-containing PEC particles were twofold lower than for PLA particles, explained by the faster release of RF from PEC-containing particles.
Conclusions
The inclusion of PEC in PLA microparticles increased the release of RF and the inhibitory effect against two bacteria species while displaying physical particle properties similar to PLA particles.
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Affiliation(s)
- Petra A Priemel
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yingya Wang
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Adam Bohr
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jorrit J Water
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mingshi Yang
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, China
| | - Hanne Mørck Nielsen
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Bohr A, Wang Y, Harmankaya N, Water JJ, Baldursdottír S, Almdal K, Beck-Broichsitter M. Molecular weight-dependent degradation and drug release of surface-eroding poly(ethylene carbonate). Eur J Pharm Biopharm 2017; 115:140-148. [DOI: 10.1016/j.ejpb.2017.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Indexed: 02/07/2023]
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Bohr A, Water JJ, Wang Y, Arnfast L, Beck-Broichsitter M. Potential of surface-eroding poly(ethylene carbonate) for drug delivery to macrophages. Int J Pharm 2016; 511:814-20. [DOI: 10.1016/j.ijpharm.2016.07.075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/28/2016] [Accepted: 07/29/2016] [Indexed: 01/06/2023]
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Vyner MC, Li A, Amsden BG. The effect of poly(trimethylene carbonate) molecular weight on macrophage behavior and enzyme adsorption and conformation. Biomaterials 2014; 35:9041-8. [DOI: 10.1016/j.biomaterials.2014.07.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/18/2014] [Indexed: 10/24/2022]
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18
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Chu D, Beck-Broichsitter M, Curdy C, Riebesehl B, Kissel T. Feasibility of macrophage mediated on-demand drug release from surface eroding poly(ethylene carbonate). Int J Pharm 2014; 465:1-4. [DOI: 10.1016/j.ijpharm.2014.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 02/02/2014] [Indexed: 11/26/2022]
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Chu D, Curdy C, Riebesehl B, Zhang Y, Beck-Broichsitter M, Kissel T. Enzyme-responsive surface erosion of poly(ethylene carbonate) for controlled drug release. Eur J Pharm Biopharm 2013; 85:1232-7. [DOI: 10.1016/j.ejpb.2013.04.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Revised: 04/03/2013] [Accepted: 04/15/2013] [Indexed: 11/30/2022]
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Barreto C, Altskär A, Fredriksen S, Hansen E, Rychwalski RW. Multiwall carbon nanotube/PPC composites: Preparation, structural analysis and thermal stability. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2013.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Chu D, Curdy C, Riebesehl B, Beck-Broichsitter M, Kissel T. In situ forming parenteral depot systems based on poly(ethylene carbonate): effect of polymer molecular weight on model protein release. Eur J Pharm Biopharm 2013; 85:1245-9. [PMID: 23791717 DOI: 10.1016/j.ejpb.2013.05.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 05/10/2013] [Accepted: 05/27/2013] [Indexed: 11/26/2022]
Abstract
The objective of this study was to investigate the effect of molecular weight (MW) on the drug release from poly(ethylene carbonate) (PEC) based surface-eroding in situ forming depots (ISFD). In phosphate buffered saline (PBS) pH 7.4, 63.7% of bovine serum albumin BSA was released from high MW PEC of 200 kDa (PEC200) in DMSO (15%, w/w) in 2 days, while during the same time period, the release of BSA from PEC41 samples was only 22.5%. At higher concentrations of PEC41 (25%, w/w), the initial burst was further reduced, and even after 6 days, only 16.3% was released. Compared to depots based on PEC200, there was lower rate of solvent release, slower phase inversion, and a denser surface in PEC41 samples. An expansion in size of PEC41 depots suggested that the polymer barrier of PEC41 impeded the diffusion of solvent out of the samples effectively. In conclusion, the initial burst of protein from ISFD of PEC41 was significantly reduced, which would be a promising candidate as polymeric carrier.
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Affiliation(s)
- Dafeng Chu
- Department of Pharmaceutics and Biopharmacy, Philipps-Universität, Marburg, Germany
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22
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Barreto C, Proppe J, Fredriksen S, Hansen E, Rychwalski RW. Graphite nanoplatelet/pyromellitic dianhydride melt modified PPC composites: Preparation and characterization. POLYMER 2013. [DOI: 10.1016/j.polymer.2013.04.068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Cornacchione LA, Qi B, Bianco J, Zhou Z, Amsden BG. Photo-Cross-Linked Poly(ethylene carbonate) Elastomers: Synthesis, in Vivo Degradation, and Determination of in Vivo Degradation Mechanism. Biomacromolecules 2012; 13:3099-107. [DOI: 10.1021/bm300913q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. A. Cornacchione
- Department of Chemical Engineering, Queen’s University, Kingston, ON, Canada
| | - B. Qi
- Department of Chemical Engineering, Queen’s University, Kingston, ON, Canada
| | - J. Bianco
- Department of Chemical Engineering, Queen’s University, Kingston, ON, Canada
| | - Z. Zhou
- Department of Chemical Engineering, Queen’s University, Kingston, ON, Canada
| | - B. G. Amsden
- Department of Chemical Engineering, Queen’s University, Kingston, ON, Canada
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Matthiesen SH, Hansen CM. Fast and non-toxic in situ hybridization without blocking of repetitive sequences. PLoS One 2012; 7:e40675. [PMID: 22911704 PMCID: PMC3404051 DOI: 10.1371/journal.pone.0040675] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 06/12/2012] [Indexed: 11/29/2022] Open
Abstract
Formamide is the preferred solvent to lower the melting point and annealing temperature of nucleic acid strands in in situ hybridization (ISH). A key benefit of formamide is better preservation of morphology due to a lower incubation temperature. However, in fluorescence in situ hybridization (FISH), against unique DNA targets in tissue sections, an overnight hybridization is required to obtain sufficient signal intensity. Here, we identified alternative solvents and developed a new hybridization buffer that reduces the required hybridization time to one hour (IQFISH method). Remarkably, denaturation and blocking against repetitive DNA sequences to prevent non-specific binding is not required. Furthermore, the new hybridization buffer is less hazardous than formamide containing buffers. The results demonstrate a significant increased hybridization rate at a lowered denaturation and hybridization temperature for both DNA and PNA (peptide nucleic acid) probes. We anticipate that these formamide substituting solvents will become the foundation for changes in the understanding and performance of denaturation and hybridization of nucleic acids. For example, the process time for tissue-based ISH for gene aberration tests in cancer diagnostics can be reduced from days to a few hours. Furthermore, the understanding of the interactions and duplex formation of nucleic acid strands may benefit from the properties of these solvents.
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25
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Barreto C, Hansen E, Fredriksen S. Novel solventless purification of poly(propylene carbonate): Tailoring the composition and thermal properties of PPC. Polym Degrad Stab 2012. [DOI: 10.1016/j.polymdegradstab.2012.03.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Drug eluting stents based on Poly(ethylene carbonate): Optimization of the stent coating process. Eur J Pharm Biopharm 2012; 80:562-70. [DOI: 10.1016/j.ejpb.2011.12.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 12/11/2011] [Accepted: 12/13/2011] [Indexed: 11/22/2022]
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27
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Bat E, Plantinga JA, Harmsen MC, van Luyn MJA, Feijen J, Grijpma DW. In vivo behavior of trimethylene carbonate and ε-caprolactone-based (co)polymer networks: degradation and tissue response. J Biomed Mater Res A 2011; 95:940-9. [PMID: 20845496 DOI: 10.1002/jbm.a.32921] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The in vivo erosion behavior of crosslinked (co)polymers based on trimethylene carbonate (TMC) and ε-caprolactone (CL) was investigated. High molecular weight poly(trimethylene carbonate) (PTMC) homopolymer- and copolymer films were crosslinked by gamma irradiation. To adjust the in vivo erosion rate of the (co)polymer films, both the irradiation dose (25, 50, or 100 kGy) for PTMC and composition (100-70 mol % TMC) at a constant irradiation dose of 25 kGy were varied. After subcutaneous implantation of irradiated films in rats, their in vivo behavior was evaluated qualitatively and quantitatively. When the irradiation dose for PTMC was increased from 25 to 100 kGy, the erosion rate of nonextracted PTMC films (determined at day 5) decreased from 39.7 ± 16.0 μm day(-1) to 15.1 ± 2.5 μm day(-1), and the number of lymphocytes in the tissue surrounding the films decreased from 235 ± 114 cells mm(-2) to 64 ± 33 cells mm(-2). The number of macrophages and giant cells at the tissue-polymer interface also decreased with increasing irradiation dose. All (co)polymer films eroded completely within 28 days of implantation. Variation of the TMC content of gamma irradiated (co)polymer films did not affect the tissue response to the gamma irradiated (co)polymer films and their in vivo erosion behavior much.
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Affiliation(s)
- Erhan Bat
- Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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28
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Xu N, Liu X, Liu Y, Zhu W, Chen F, Shen Z. Synthesis and properties of random copolymers of 2,2-dimethyltrimethylene carbonate and ethylene carbonate catalyzed by lanthanide tris(2,6-di-tert-butyl-4-methylphenolate). J Appl Polym Sci 2010. [DOI: 10.1002/app.30514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Timbart L, Tse MY, Pang SC, Babasola O, Amsden BG. Low Viscosity Poly(trimethylene carbonate) for Localized Drug Delivery: Rheological Properties andin vivoDegradation. Macromol Biosci 2009; 9:786-94. [DOI: 10.1002/mabi.200800318] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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30
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Bat E, van Kooten TG, Feijen J, Grijpma DW. Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films. Biomaterials 2009; 30:3652-61. [DOI: 10.1016/j.biomaterials.2009.03.033] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 03/18/2009] [Indexed: 10/20/2022]
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31
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Chapanian R, Tse MY, Pang SC, Amsden BG. The role of oxidation and enzymatic hydrolysis on the in vivo degradation of trimethylene carbonate based photocrosslinkable elastomers. Biomaterials 2009; 30:295-306. [DOI: 10.1016/j.biomaterials.2008.09.038] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 09/14/2008] [Indexed: 11/30/2022]
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32
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Abstract
Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.
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Affiliation(s)
- Trishul Artham
- Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, India
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33
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Unger F, Westedt U, Hanefeld P, Wombacher R, Zimmermann S, Greiner A, Ausborn M, Kissel T. Poly(ethylene carbonate): A thermoelastic and biodegradable biomaterial for drug eluting stent coatings? J Control Release 2007; 117:312-21. [PMID: 17207879 DOI: 10.1016/j.jconrel.2006.11.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/30/2006] [Accepted: 11/07/2006] [Indexed: 11/16/2022]
Abstract
A first feasibility study exploring the utility of poly(ethylene carbonate) (PEC) as coating material for drug eluting stents under in vitro conditions is reported. PEC (Mw 242 kDa, Mw/Mn=1.90) was found to be an amorphous polymer with thermoelastic properties. Tensile testing revealed a stress to strain failure of more than 600%. These properties are thought to be advantageous for expanding coated stents. In vitro cytotoxicity tests showed excellent cytocompatibility of PEC. Based on these findings, a new stenting concept was suggested, pre-coating a bare-metal stent with PPX-N as non-biodegradable basis and applying a secondary PEC coating using an airbrush method. After manual expansion, no delamination or destruction of the coating could be observed using scanning electron microscopy. The surface degradation-controlled release mechanism of PEC may provide the basis for "on demand" drug eluting stent coatings, releasing an incorporated drug predominantly at an inflamed implantation site upon direct contact with superoxide-releasing macrophages. As a release model, metal plates of a defined size and area were coated under the same conditions as the stents with PEC containing radiolabelled paclitaxel. An alkaline KO(2-) solution served as a superoxide source. Within 12 h, 100% of the incorporated paclitaxel was released, while only 20% of the drug was released in non-superoxide releasing control buffer within 3 weeks.
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Affiliation(s)
- F Unger
- Faculty of Pharmacy, Department of Pharmaceutics and Biopharmacy, Philipps-University, Ketzerbach 63, D-35032 Marburg, Germany
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34
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Zhang Z, Kuijer R, Bulstra SK, Grijpma DW, Feijen J. The in vivo and in vitro degradation behavior of poly(trimethylene carbonate). Biomaterials 2006; 27:1741-8. [PMID: 16221493 DOI: 10.1016/j.biomaterials.2005.09.017] [Citation(s) in RCA: 295] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 09/06/2005] [Indexed: 11/15/2022]
Abstract
The in vivo and in vitro degradation behavior of poly(trimethylene carbonate) (PTMC) polymers with number average molecular weights of 69 x 10(3), 89 x 10(3), 291 x 10(3) and 457 x 10(3)g/mol (respectively abbreviated as PTMC(69), PTMC(89), PTMC(291) and PTMC(457)) was investigated in detail. PTMC rods (3mm in diameter and 4mm in length) implanted in the femur and tibia of rabbits degraded by surface erosion. The mass loss of high molecular weight PTMC(457) specimens was 60wt% in 8 wks, whereas the mass loss of the lower molecular weight PTMC(89) specimens in the same period was 3 times lower. PTMC discs of different molecular weights immersed in lipase solutions (lipase from Thermomyces lanuginosus) degraded by surface erosion as well. The mass and thickness of high molecular weight PTMC(291) discs decreased linearly in time with an erosion rate of 6.7 microm/d. The erosion rate of the lower molecular weight PTMC(69) specimens was only 1.4mum/d. It is suggested that the more hydrophilic surface of the PTMC(69) specimens prevents the enzyme from acquiring a (hyper)active conformation. When PTMC discs were immersed in media varying in pH from 1 to 13, the non-enzymatic hydrolysis was extremely slow for both the high and low molecular weight samples. It can be concluded that enzymatic degradation plays an important role in the surface erosion of PTMC in vivo.
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Affiliation(s)
- Zheng Zhang
- Institute for Biomedical Technology (BMTI) and Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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35
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Zelikin AN, Putnam D. Poly(carbonate−acetal)s from the Dimer Form of Dihydroxyacetone. Macromolecules 2005. [DOI: 10.1021/ma050049v] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander N. Zelikin
- Department of Biomedical Engineering and the School of Chemical and Biomolecular Engineering, 270 Olin Hall, Cornell University, Ithaca, New York 14853
| | - David Putnam
- Department of Biomedical Engineering and the School of Chemical and Biomolecular Engineering, 270 Olin Hall, Cornell University, Ithaca, New York 14853
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36
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Abstract
Biochronomer (AP Pharma) is a fourth-generation poly(ortho ester) prepared by the condensation of diols and a diketene acetal. The polymer contains a copolymerised latent acid whose concentration controls erosion rate. The polymer has been shown to undergo a surface erosion process and a number of applications have been explored. Among these, the delivery of plasmid DNA for vaccines is currently of most interest. This application takes advantage of the acid-labile nature of the polymer, which leads to rapid polymer hydrolysis and hence rapid release of plasmid DNA once internalised in the acidic environment within the endosomes, and the non-acidic environment within the polymer that conserves plasmid DNA conformation. A low molecular semisolid polymer is now in Phase II clinical trials for the delivery of mepivacaine to control postoperative pain, and in Phase I clinical trials for the systemic delivery of granisetron to control nausea.
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37
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Acemoglu M. Chemistry of polymer biodegradation and implications on parenteral drug delivery. Int J Pharm 2004; 277:133-9. [PMID: 15158976 DOI: 10.1016/j.ijpharm.2003.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2002] [Revised: 01/09/2003] [Accepted: 06/23/2003] [Indexed: 11/28/2022]
Abstract
Most polymeric implants are biodegraded by one of two common chemical degradation mechanisms: (i). hydrolysis and (ii). oxidation. The chemical structure is among the most important factors which affect the biodegradation of polymeric implants. Hydrolytic biodegradations are often accompanied by substantial decrease of pH, whilst oxidative biodegradation processes are usually very slow due to consumption of stoichiometric amounts of oxidising agents. A dramatic acceleration of the biodegradation can be expected, if the biodegradation can be initiated by catalytic amounts of oxidation agents. Poly(ethylene carbonate) (PEC) and poly(trimethylene carbonate) (PTMC) are presumably biodegraded by such catalytic oxidation processes. Their biodegradation shows all the characteristics of surface erosion. Poly(ethylene carbonate) is utilised as a surface eroding biocompatible polymer for controlled delivery of peptide and protein drugs.
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Affiliation(s)
- M Acemoglu
- Process R & D, TRD-CHAD, Novartis Pharma AG, Basel CH-4002, Switzerland.
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38
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Pêgo AP, Van Luyn MJA, Brouwer LA, van Wachem PB, Poot AA, Grijpma DW, Feijen J. In vivo behavior of poly(1,3-trimethylene carbonate) and copolymers of 1,3-trimethylene carbonate with D,L-lactide or epsilon-caprolactone: Degradation and tissue response. J Biomed Mater Res A 2004; 67:1044-54. [PMID: 14613255 DOI: 10.1002/jbm.a.10121] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The degradation and the tissue response evoked by poly(1,3-trimethylene carbonate) [poly(TMC)] and copolymers of TMC with either 52 mol % D,L-lactide (DLLA) or 89 mol % epsilon-caprolactone (CL) were evaluated in vivo by subcutaneous implantation of polymer films in rats for periods up to one year. Poly(TMC) specimens were extensively degraded after 3 weeks and, as confirmed by histology, totally resorbed in less than a year. A fast linear decrease in thickness and mass without a change in molecular weight was observed. Initially an acute sterile inflammatory tissue reaction, caused by the implantation procedure, was observed, followed by a mild macrophage-mediated foreign body reaction that lasted during the resorption period of the polymer. It is concluded that in vivo, poly(TMC) is degraded via surface erosion involving cellular-mediated processes. The degradation of the copolymers was slower than that of poly(TMC), taking place via autocatalyzed bulk hydrolysis, preferentially of ester bonds. The TMC-DLLA copolymer degraded 20 times faster than the TMC-CL one. In both cases, the tissue reaction upon implantation resembled a sterile inflammatory reaction followed by a foreign body reaction that led to the polymer encapsulation. Significant mass loss was only observed for the TMC-DLLA copolymer, which underwent 96% mass loss in 1 year. When extensive mass loss started, a mild-to-moderate secondary foreign body reaction, related to clearance of the polymer fragments, was triggered. The results presented in this study demonstrate that poly(TMC) and both TMC copolymers are biodegradable and biocompatible materials, making these polymers attractive for the preparation of short- and long-term degradable devices for soft tissue engineering.
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Affiliation(s)
- A P Pêgo
- Institute for Biomedical Technology (BMTI) and Department of Polymer Chemistry and Biomaterials, Faculty of Chemical Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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39
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van Dijkhuizen-Radersma R, Roosma JR, Sohier J, Péters FLAMA, van den Doel M, van Blitterswijk CA, de Groot K, Bezemer JM. Biodegradable poly(ether-ester) multiblock copolymers for controlled release applications: Anin vivoevaluation. J Biomed Mater Res A 2004; 71:118-27. [PMID: 15368261 DOI: 10.1002/jbm.a.30136] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Multiblock poly(ether-ester)s based on poly(ethylene glycol), butylene terephthalate, and butylene succinate segments were evaluated for their in vivo degradation and biocompatibility in order to establish a correlation with previously reported in vitro results. Porous polymer sheets were implanted subcutaneously for 32 weeks in rats. The degradation was monitored visually (histology), by molecular weight (GPC), and by copolymer composition (NMR). Substitution of the aromatic terephthalate units by aliphatic succinate units was shown to accelerate the degradation rate of the copolymers. Direct correlation of the in vivo and in vitro degradation of the porous implants showed a slightly faster initial molecular weight decrease in vivo. Besides hydrolysis, oxidation occurs in vivo due to the presence of radicals produced by inflammatory cells. In addition, the higher molecular weight plateau of the residue found in vivo indicated a higher solubility of the oligomers in the extracellular fluid compared to a phosphate buffer. Minor changes in the poly(ether-ester) compositions were noted due to degradation. Microscopically, fragmentation of the porous implants was observed in time. At later stages of degradation, macrophages were observed phagocytozing small polymer particles. Both in vitro cytotoxicity studies and histology on in vivo samples proved the biocompatibility of the poly(ether-ester)s.
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40
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Dadsetan M, Christenson EM, Unger F, Ausborn M, Kissel T, Hiltner A, Anderson JM. In vivo biocompatibility and biodegradation of poly(ethylene carbonate). J Control Release 2003; 93:259-70. [PMID: 14644576 DOI: 10.1016/j.jconrel.2003.08.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Biodegradation and biocompatibility of poly(ethylene carbonate) (PEC) was examined using an in vivo cage implant system. Exudate analysis showed that PEC and PEC degradation products were biocompatible and induced minimal inflammatory and wound healing responses. Adherent foreign body giant cells (FBGCs) caused pitting on the PEC surface, which led to extensive degradation over time. Data obtained from molecular weight and examination of film cross-sections in the scanning electron microscope (SEM) indicated that PEC underwent surface erosion with no change to the remaining bulk. Attenuated total reflectance infrared (ATR-FTIR) spectroscopy was used to characterize the chemical degradation. Superoxide anion released from inflammatory cells appeared to initiate an "unzipping" mechanism of degradation by deprotonation of PEC hydroxyl end groups. The resulting alkoxide ion participated in a concerted mechanism involving water and the carbonate carbonyl, leading to elimination of ethylene glycol. Carbonate ions decomposed further with release of carbon dioxide to regenerate alkoxide ion.
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Affiliation(s)
- M Dadsetan
- Center for Applied Polymer Research, Department of Macromolecular Science, Case Western Reserve University, Cleveland, OH 44106-7202, USA
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41
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Walsh MC, Banas JA, Mudzinski SP, Preissler MT, Graziano RF, Gosselin EJ. A two-component modular approach for enhancing T-cell activation utilizing a unique anti-FcgammaRI-streptavidin construct and microspheres coated with biotinylated-antigen. BIOMOLECULAR ENGINEERING 2003; 20:21-33. [PMID: 12485681 DOI: 10.1016/s1389-0344(02)00089-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The professional antigen presenting cell (APC) plays an essential role in the initiation and propagation of the acquired immune response. Thus, much work has been done in designing strategies that target vaccine antigen (Ag) to APC. Utilizing recombinant DNA technology, we have created a unique two-component system that delivers biotinylated Ag to the Fc gamma receptor type I (FcgammaRI) on APC. Our studies demonstrate that we can successfully engineer FcgammaRI-specific targeting element proteins that simultaneously bind both biotin and recognize FcgammaRI. Additionally, we are able to engineer biotinylated Ag, which form functional elements when adsorbed onto latex microspheres. Furthermore, the targeting and functional element components bind to each other and successfully form two-component immunogens. T-cell activation in response to targeted Ag-laden microspheres is 10- to 100-fold greater than the response to the non-targeted Ag-laden microspheres. This enhancement is 100- to 1000-fold greater than the responses generated to soluble Ag. Thus, our results suggest that specific targeting of Ag-laden microspheres to FcgammaRI may significantly enhance the adjuvant properties of microparticulate delivery systems. Further development of this system may help to elucidate the mechanisms involved in generating enhanced responses to APC-targeted vaccines and significantly advance vaccine technology.
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Affiliation(s)
- Mary C Walsh
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12201, USA
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