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Bhutkar SP, Millard PE, Preece JA, Zhang Z. Microplastic-Free Microcapsules Using Supramolecular Self-Assembly of Bis-Urea Molecules at an Emulsion Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 38990556 DOI: 10.1021/acs.langmuir.4c00541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
Encapsulation technology is well established for entrapping active ingredients within an outer shell for their protection and controlled release. However, many solutions employed industrially use nondegradable cross-linked synthetic polymers for shell formation. To curb rising microplastic pollution, regulatory policies are forcing industries to substitute the use of such intentionally added microplastics with environmentally friendly alternatives. This work demonstrates a one-pot process to make microplastic-free microcapsules using supramolecular self-assembly of bis-ureas. Molecular bis-urea species generated in-situ spontaneously self-assemble at the interface of an oil-in-water emulsion via hydrogen bonding to form a shell held together by noncovalent bonds. In addition, Laponite nanodiscs were introduced in the formulation to restrict aggregation observed during the self-assembly and to reduce the porosity of the shell, leading to well-dispersed microcapsules (mean Sauter diameter d [3,2] ∼ 5 μm) with high encapsulation efficiency (∼99%). Accelerated release tests revealed an increase in characteristic release time of the active by more than an order of magnitude after encapsulation. The mechanical strength parameters of these capsules were comparable to some of the commercial, nondegradable melamine-formaldehyde microcapsules. With mild operating conditions in an aqueous environment, this technology has real potential to offer an industrially viable method for producing microplastic-free microcapsules.
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Affiliation(s)
| | | | - Jon A Preece
- School of Chemistry, University of Birmingham, Birmingham B15 2TT, U.K
| | - Zhibing Zhang
- School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, U.K
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2
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Panigrahi SK, Das S, Majumdar S. Unveiling the potentials of hydrophilic and hydrophobic polymers in microparticle systems: Opportunities and challenges in processing techniques. Adv Colloid Interface Sci 2024; 326:103121. [PMID: 38457900 DOI: 10.1016/j.cis.2024.103121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/24/2024] [Accepted: 02/28/2024] [Indexed: 03/10/2024]
Abstract
Conventional drug delivery systems are associated with various shortcomings, including low bioavailability and limited control over release. Biodegradable polymeric microparticles have emerged as versatile carriers in drug delivery systems addressing all these challenges. This comprehensive review explores the dynamic landscape of microparticles, considering the role of hydrophilic and hydrophobic materials. Within the continuously evolving domain of microparticle preparation methods, this review offers valuable insights into the latest advancements and addresses the factors influencing microencapsulation, which is pivotal for harnessing the full potential of microparticles. Exploration of the latest research in this dynamic field unlocks the possibilities of optimizing microencapsulation techniques to produce microparticles of desired characteristics and properties for different applications, which can help contribute to the ongoing evolution in the field of pharmaceutical science.
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Affiliation(s)
- Subrat Kumar Panigrahi
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Telangana 502285, India
| | - Sougat Das
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Telangana 502285, India
| | - Saptarshi Majumdar
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Telangana 502285, India.
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3
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Mytara AD, Chronaki K, Nikitakos V, Papaspyrides CD, Beltsios K, Vouyiouka S. Synthesis of Polyamide-Based Microcapsules via Interfacial Polymerization: Effect of Key Process Parameters. MATERIALS (BASEL, SWITZERLAND) 2021; 14:5895. [PMID: 34640292 PMCID: PMC8510004 DOI: 10.3390/ma14195895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/23/2021] [Accepted: 09/29/2021] [Indexed: 01/21/2023]
Abstract
Polyamide microcapsules have gathered significant research interest during the past years due to their good barrier properties; however, the potential of their application is limited due to the fragility of the polymeric membrane. Fully aliphatic polyamide microcapsules (PA MCs) were herein prepared from ethylene diamine and sebacoyl chloride via interfacial polymerization, and the effect of key encapsulation parameters, i.e., monomers ratio, core solvent, stirring rate and time during the polymerization step, were examined concerning attainable process yield and microcapsule properties (shell molecular weight and thermal properties, MC size and morphology). The process yield was found to be mainly influenced by the nature of the organic solvent, which was correlated to the diffusion potential of the diamine from the aqueous phase to the organic core through the polyamide membrane. Thus, spherical microcapsules with a size between 14 and 90 μm and a yield of 33% were prepared by using toluene as core solvent. Milder stirring during the polymerization step led to an improved microcapsule morphology; yet, the substantial improvement of mechanical properties remains a challenge.
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Affiliation(s)
- Angeliki D. Mytara
- Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece; (A.D.M.); (K.C.); (V.N.); (C.D.P.)
| | - Konstantina Chronaki
- Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece; (A.D.M.); (K.C.); (V.N.); (C.D.P.)
| | - Vasilis Nikitakos
- Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece; (A.D.M.); (K.C.); (V.N.); (C.D.P.)
| | - Constantine D. Papaspyrides
- Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece; (A.D.M.); (K.C.); (V.N.); (C.D.P.)
| | - Konstantinos Beltsios
- Department of Materials Science and Engineering, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece
| | - Stamatina Vouyiouka
- Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 15780 Athens, Greece; (A.D.M.); (K.C.); (V.N.); (C.D.P.)
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4
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Moslemi M, Hosseini H, Neyestani TR, Akramzadeh N, Mazaheri Nezhad Fard R. Effects of non-digestive polymers used in iron encapsulation on calcium and iron apparent absorption in rats fed by infant formula. J Trace Elem Med Biol 2018; 50:393-398. [PMID: 30262310 DOI: 10.1016/j.jtemb.2018.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/12/2018] [Accepted: 08/13/2018] [Indexed: 01/02/2023]
Abstract
Iron deficiency anemia is a common problem of all ages in developed and developing countries. Various strategies are used by governments and industries to solve this problem. One of these strategies is iron fortification. In the present study, novel iron microcapsules were designed without any changes in their effects on other ingredients in infant milk formulas. Resistant starch-pectin-iron and pectin-iron microparticles were added to infant powdered milk models. Furthermore, animal studies were carried out. Fecal iron and calcium were assessed using flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy, respectively. Then, apparent iron and calcium absorptions were calculated. Sensory evaluation was carried out on reconstituted powdered milks. Results showed that iron absorption in rats treated by pectin-coated particles was significantly higher than that in controls with no significant effects on calcium absorption. No significant differences were observed in sensory evaluation.
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Affiliation(s)
- Masoumeh Moslemi
- Food and Drug Administration, Ministry of Health and Medical Education, No. 30, Vahid Nazari St., Fakhre Razi St., Enghelab St., Tehran, Iran
| | - Hedayat Hosseini
- Department of Food Science and Technology, National Nutrition and Food Technology Research Institute (NNFTRI) and Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, No. 7, Shahid Farahzadi Blvd., Shahid Hafezi St. (Western Arghavan), Ghods Town, Tehran, Iran.
| | - Tirang Reza Neyestani
- Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute (NNFTRI), Shahid Beheshti University of Medical Sciences, No. 7, Shahid Farahzadi Blvd., Shahid Hafezi St. (Western Arghavan), Ghods Town, Tehran, Iran
| | - Naeimeh Akramzadeh
- Student Research Committee, Department of Food Technology, Faculty of Nutrition Sciences and Food Technologies, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, No. 7, Shahid Farahzadi Blvd., Shahid Hafezi St. (Western Arghavan), Ghods Town, Tehran, Iran
| | - Ramin Mazaheri Nezhad Fard
- Division of Food Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Pour Sina St., Keshavarz Blvd., Tehran, Iran; Food Microbiology Research Centre, School of Public Health, Tehran University of Medical Sciences, Pour Sina St., Keshavarz Blvd., Tehran, Iran
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5
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Kutyreva MP, Gataulina AR, Kutyrev GA, Ulakhovich NA, Newman T, Khasanova EM, Bondar OV, Yurtaeva SV, Ziganshina SA, Khaldeeva EV. Hyperbranched polyester poly(3-diethylaminepropionate)s and their copper(II) complexes: Synthesis, characterization and biological investigation. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Chakravarthy D, Smith DJ. Preparation of a Dextran-Based Degradable Absorbent Suitable for Wound Healing Applications. J BIOACT COMPAT POL 2016. [DOI: 10.1177/088391159501000403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydrolytically degradable microspheres were prepared by crosslinkng dextran under alkaline conditions with cyanogen bromide (CNBr). The crosslinking was performed in a water-in-oil type heterophase suspension medium. Dextran Mws of 500,000 and 40,000 were used for the preparations, CNBr:dextran-OH mole ratios ranged from 0.021:1 to 0.21:1. The microspheres absorbed significant quantities of water (20-45 times their own weight), and were shown to degrade in neutral buffer to soluble and non-toxic products. Hydration and degradation behavior varied linearly with the ratios of CNBr to dextran. The physical properties were dependent on the molecular weights of the dextrans used in the preparations. In contrast to epichlorohydrin crosslinked dextran microspheres that are resistant to hydrolysis and only degrade enzymatically, the described microspheres degrade more rapidly by simple hydrolysis of the iminocarbonate bonds that constitute the microspheres. Such degradative properties are ideal in the application of the microspheres as wound filers and as components of wound dressings.
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Affiliation(s)
| | - D. J. Smith
- Department of Chemistry and Department of Biomedical Engineering, University of Akron, Akron, OH, 44325-3601
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7
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Silk fibroin nanoparticle as a novel drug delivery system. J Control Release 2015; 206:161-76. [DOI: 10.1016/j.jconrel.2015.03.020] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 01/12/2023]
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8
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Doblhofer E, Scheibel T. Engineering of recombinant spider silk proteins allows defined uptake and release of substances. J Pharm Sci 2014; 104:988-94. [PMID: 25546241 DOI: 10.1002/jps.24300] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 01/01/2023]
Abstract
Drug delivery carriers stabilize drugs and control their release, expanding the therapeutic window, and avoiding side effects of otherwise freely diffusing drugs in the human body. Materials used as carrier vehicles have to be biocompatible, biodegradable, nontoxic, and nonimmunogenic. Previously, particles made of the recombinant spider silk protein eADF4(C16) could be effectively loaded with positively and neutrally charged model substances. Here, a new positively charged variant thereof, named eADF4(κ16), has been engineered. Its particle formation is indistinguishable to that of polyanionic eADF4(C16), but in contrast polycationic eADF4(κ16) allows incorporation of negatively charged substances. Both high-molecular-weight substances, such as nucleic acids, and low-molecular-weight substances could be efficiently loaded onto eADF4(κ16) particles, and release of nucleic acids was shown to be well controlled.
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Affiliation(s)
- Elena Doblhofer
- Thomas Scheibel, Lehrstuhl Biomaterialien, Fakultät für Ingenieurwissenschaften, Universität Bayreuth, Bayreuth, 95440, Germany
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9
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Lammel A, Schwab M, Hofer M, Winter G, Scheibel T. Recombinant spider silk particles as drug delivery vehicles. Biomaterials 2011; 32:2233-40. [DOI: 10.1016/j.biomaterials.2010.11.060] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 11/26/2010] [Indexed: 10/18/2022]
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10
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Spiess K, Lammel A, Scheibel T. Recombinant spider silk proteins for applications in biomaterials. Macromol Biosci 2010; 10:998-1007. [PMID: 20602494 DOI: 10.1002/mabi.201000071] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Due to their extraordinary mechanical and biochemical properties, silks have long been in focus of research. In vivo, fibers are formed from silk proteins, in vitro, however, a variety of materials can be produced in addition to fibers including capsules, particles, films, foams, and gels. The versatility of silk proteins, along with their biocompatibility, biodegradability, and potential for processing in aqueous solution under ambient conditions make silk-based materials good candidates for biomedical applications such as drug delivery systems and scaffolds for tissue engineering. Here, we summarize recent progress in research employing recombinantly produced engineered spider silk proteins with a focus on the fundamentals of silk protein processing. We highlight recombinant spider silk films and particles as morphologies that represent model systems with adjustable material properties controlled by process parameters.
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Affiliation(s)
- Kristina Spiess
- Lehrstuhl Biomaterialien, Fakultät Angewandte Naturwissenschaften, Universität Bayreuth Universitätsstr. 30, 95440 Bayreuth, Germany
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11
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Seo SA, Khang G, Rhee JM, Kim J, Lee HB. Study on in vitro release patterns of fentanyl-loaded PLGA microspheres. J Microencapsul 2010. [DOI: 10.3109/02652040309178347] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- S.-A. Seo
- Department of Polymer Science and Technology, Chonbuk National University, 664-14 Dukjin, Chonju, 561-756, Korea
| | - G. Khang
- Department of Polymer Science and Technology, Chonbuk National University, 664-14 Dukjin, Chonju, 561-756, Korea
| | - J. M. Rhee
- Department of Polymer Science and Technology, Chonbuk National University, 664-14 Dukjin, Chonju, 561-756, Korea
| | - J. Kim
- Department of Advanced Organic Materials Engineering, Chonbuk National University, 664-14 Dukjin, Chonju, 561-756, Korea
| | - H. B. Lee
- Biomaterials Laboratory, Korea Research Institute of Chemical Technology, PO Box 107, Yusung, Taejon, 305-606, Korea
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12
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Lammel A, Hu X, Park SH, Kaplan DL, Scheibel T. Controlling silk fibroin particle features for drug delivery. Biomaterials 2010; 31:4583-91. [PMID: 20219241 PMCID: PMC2846964 DOI: 10.1016/j.biomaterials.2010.02.024] [Citation(s) in RCA: 322] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 02/10/2010] [Indexed: 11/15/2022]
Abstract
Silk proteins are a promising material for drug delivery due to their aqueous processability, biocompatibility, and biodegradability. A simple aqueous preparation method for silk fibroin particles with controllable size, secondary structure and zeta potential is reported. The particles were produced by salting out a silk fibroin solution with potassium phosphate. The effect of ionic strength and pH of potassium phosphate solution on the yield and morphology of the particles was determined. Secondary structure and zeta potential of the silk particles could be controlled by pH. Particles produced by salting out with 1.25 m potassium phosphate pH 6 showed a dominating silk II (crystalline) structure whereas particles produced at pH 9 were mainly composed of silk I (less crystalline). The results show that silk I-rich particles possess chemical and physical stability and secondary structure which remained unchanged during post treatments even upon exposure to 100% ethanol or methanol. A model is presented to explain the process of particle formation based on intra- and intermolecular interactions of the silk domains, influenced by pH and kosmotropic salts. The reported silk fibroin particles can be loaded with small molecule model drugs, such as alcian blue, rhodamine B, and crystal violet, by simple absorption based on electrostatic interactions. In vitro release of these compounds from the silk particles depends on charge-charge interactions between the compounds and the silk. With crystal violet we demonstrated that the release kinetics are dependent on the secondary structure of the particles.
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Affiliation(s)
- Andreas Lammel
- Lehrstuhl Biotechnologie, Lichtenbergstraße 4, Technische Universität München, D-85747 Garching, Germany
| | - Xiao Hu
- Departments of Biomedical Engineering, Chemical and Biological Engineering, Bioengineering and Biotechnology Center, Tufts University, Medford 02155, MA, USA
| | - Sang-Hyug Park
- Departments of Biomedical Engineering, Chemical and Biological Engineering, Bioengineering and Biotechnology Center, Tufts University, Medford 02155, MA, USA
| | - David L. Kaplan
- Departments of Biomedical Engineering, Chemical and Biological Engineering, Bioengineering and Biotechnology Center, Tufts University, Medford 02155, MA, USA
| | - Thomas Scheibel
- Lehrstuhl Biomaterialien, Universitätsstraße 30, Universität Bayreuth, D-95440 Bayreuth, Germany
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13
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Literature Alerts. J Microencapsul 2008. [DOI: 10.3109/02652049109069569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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14
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Cosco S, Ambrogi V, Musto P, Carfagna C. Properties of poly(urea-formaldheyde) microcapsules containing an epoxy resin. J Appl Polym Sci 2007. [DOI: 10.1002/app.26263] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Coulembier O, Mespouille L, Hedrick JL, Waymouth RM, Dubois P. Metal-Free Catalyzed Ring-Opening Polymerization of β-Lactones: Synthesis of Amphiphilic Triblock Copolymers Based on Poly(dimethylmalic acid). Macromolecules 2006. [DOI: 10.1021/ma060552n] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Olivier Coulembier
- Laboratory of Polymeric and Composite Materials (LPCM), University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Laetitia Mespouille
- Laboratory of Polymeric and Composite Materials (LPCM), University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - James L. Hedrick
- Laboratory of Polymeric and Composite Materials (LPCM), University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Robert M. Waymouth
- Laboratory of Polymeric and Composite Materials (LPCM), University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Philippe Dubois
- Laboratory of Polymeric and Composite Materials (LPCM), University of Mons-Hainaut, Place du Parc 20, B-7000 Mons, Belgium, IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, and Department of Chemistry, Stanford University, Stanford, California 94305
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16
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Li S, Vert M. Synthesis, Characterization, and Stereocomplex-Induced Gelation of Block Copolymers Prepared by Ring-Opening Polymerization of l(d)-Lactide in the Presence of Poly(ethylene glycol). Macromolecules 2003. [DOI: 10.1021/ma034734i] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Suming Li
- Centre de Recherche sur les Biopolymères Artificiels, Faculté de Pharmacie, 15 Avenue Charles Flahault, 34060 Montpellier, France
| | - Michel Vert
- Centre de Recherche sur les Biopolymères Artificiels, Faculté de Pharmacie, 15 Avenue Charles Flahault, 34060 Montpellier, France
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17
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Gao C, Xu Y, Yan D, Chen W. Water-soluble degradable hyperbranched polyesters: novel candidates for drug delivery? Biomacromolecules 2003; 4:704-12. [PMID: 12741788 DOI: 10.1021/bm025738i] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel approach to hyperbranched polymers is presented in this work. Hyperbranched polyesters with a large amount of terminal hydroxyl groups are prepared by a one-pot synthesis from commercially available AB-type and CD(n)-type monomers (n >/= 2). In this paper, Michael addition of diethanolamine (CD(2)) or N-methyl-d-glucamine (CD(5)) to methyl acrylate (AB) generates dominantly AD(n)-type intermediates. Further self-condensation of intermediates at higher temperature and in the presence of catalyst gives hyperbranched polyesters. Because of the tertiary amino groups in the backbone and the hydroxyl groups in the linear and terminal units, the resulting hyperbranched polyester is highly soluble in water. Furthermore, the hyperbranched polymer is degradable because of its ester units. So, the water-soluble hyperbranched polyesters might be applied as a novel material for drug delivery.
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Affiliation(s)
- Chao Gao
- College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China
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18
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Evaluation ofin vitro release profiles of fentanyl-loaded PLGA oligomer microspheres. Macromol Res 2002. [DOI: 10.1007/bf03218313] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Seo SA, Choi HS, Khang G, Rhee JM, Lee HB. A local delivery system for fentanyl based on biodegradable poly(L-lactide-co-glycolide) oligomer. Int J Pharm 2002; 239:93-101. [PMID: 12052694 DOI: 10.1016/s0378-5173(02)00074-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To obtain a sustained fentanyl delivery with effective and precise control, fentanyl loaded wafer was fabricated using poly(L-lactide-co-glycolide) (PLGA) oligomer by direct compression method. XRD and DSC analysis indicated the presence of crystalline drug in the wafers. The release of fentanyl from PLGA wafer was determined to be primarily diffusion controlled, but swelling and erosion also contributed to the release process. In vitro release studies showed that different release patterns and rates could be achieved by simply modifying factors in the preparation conditions. The wafer degradation profiles were also investigated to understand the drug release mechanism. Gravimetric studies of mass loss of wafers during the incubation revealed that the weight loss increased apparently after 4 days. These results indicate that the polymer degradation was contributed to drug release followed by diffusion. From the results, this constant localized release system can potentially provide anesthesia for a longer period than injection or topical administration.
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Affiliation(s)
- Sun-Ah Seo
- Department of Polymer Science and Technology, Chonbuk National University, Dukjin Dong, Chonju 561-756, South Korea
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20
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Choi HS, Seo SA, Khang G, Rhee JM, Lee HB. Preparation and characterization of fentanyl-loaded PLGA microspheres: in vitro release profiles. Int J Pharm 2002; 234:195-203. [PMID: 11839450 DOI: 10.1016/s0378-5173(01)00968-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We developed several kinds of fentanyl-loaded poly(L-lactide-co-glycolide) (PLGA) microspheres (FMS) for sustained release of fentanyl. FMS were prepared by an emulsion solvent-evaporation method. In this study, the influences of several preparation parameters, such as initial drug loading, polymer concentration, and solvent volume on the release patterns of fentanyl were investigated. Furthermore, it has been well noted that the detection of fentanyl is extremely difficult because its clinical dose level is very low, about 1-3 ng/ml, in cancer-patient treatment. Therefore, we also developed a rapid and sensitive determination method for fentanyl in systemic circulation by employing gas chromatography (GC) system. Fentanyl was slowly released from FMS over 15 days with a quasi-zero order property. From the results, our FMS may be good formulations to deliver the analgesics and suitable for the treatment of severe pain over long periods.
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Affiliation(s)
- Hak Soo Choi
- Department of Polymer Science and Technology, Chonbuk National University, 664-14 Dukjin, Chonju 561-756, Republic of Korea
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21
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Cai Q, Bei J, Wang S. In vitro study on the drug release behavior from Polylactide-based blend matrices. POLYM ADVAN TECHNOL 2002. [DOI: 10.1002/pat.222] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Synthesis of p-methoxyphenacylmethacrylate: its characterization, polymerization and preparation of the oxime and 2,4-dinitrophenylhydrazone derivatives. REACT FUNCT POLYM 2001. [DOI: 10.1016/s1381-5148(00)00069-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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23
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Dittrich M, Hampl J, Soukup F. Branched oligoester microspheres fabricated by a rapid emulsion solvent extraction method. J Microencapsul 2000; 17:587-98. [PMID: 11038118 DOI: 10.1080/026520400417649] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Methyl formate was used as the solvent of biodegradable oligoesters for the fabrication of microspheres with encapsulated bovine serum albumin (BSA). The procedure of dispersion of the double emulsion of the w/o/w type and its dilution and solvent extraction is very rapid, taking only several minutes. A higher yield and better encapsulation efficiency were obtained with copolymers of DL-lactic acid with mannitol than with pure linear poly DL-lactic acid. The procedure was accelerated, and yields and encapsulation efficacy were enhanced by the addition of 5% methyl formate to the external water phase. The microspheres were smaller than 100 microm. No benefits were obtained from the addition of wetting agents or other additives to the intermediate (oligoesteric) phase. Further development should concentrate particularly on hydrodynamic conditions and optimization of the composition of the external phase.
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Affiliation(s)
- M Dittrich
- Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic.
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Arshady R. in vivo targeting of colloidal carriers by novel graft copolymers. J Mol Recognit 1996; 9:536-42. [PMID: 9174937 DOI: 10.1002/(sici)1099-1352(199634/12)9:5/6<536::aid-jmr297>3.0.co;2-s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
One of the major obstacles to the targeted delivery of colloidal carriers (nanocapsules) is the body's own defence mechanism in capturing foreign particles by the reticuloendothelial system (RES). This means that following intravenous administration, practically all nanometer size particles are captured by the RES (mainly the liver). This paper draws attention to a recent initiative on the design of 'macromolecular homing devices' which seem to disguise nanoparticles from the RES, and hence are of potential interest for the targeted delivery of nanocapsular carriers. The idea is based on a graft copolymer model embodying a link site for attachment (binding) to the carrier, a floating pad for maintaining the particles afloat in the blood stream, an affinity ligand for site-specific delivery and a structural tune for balancing the overall structure of the homing device. A general synthetic scheme for the preparation of such graft copolymers is given, and preliminary biological evaluations relating to the floating pad concept are discussed.
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Affiliation(s)
- R Arshady
- Department of Chemistry, Imperial College of Science, Technology and Medicine, University of London, UK
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25
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Arabi H, Hashemi SA, Fooladi M. Microencapsulation of allopurinol by solvent evaporation and controlled release investigation of drugs. J Microencapsul 1996; 13:527-35. [PMID: 8864990 DOI: 10.3109/02652049609026038] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The microencapsulation of drugs is gaining importance in many research activities. A common technique for preparing microcapsules is the solvent evaporation method which is simple but has a large number of reaction control parameters. This study reports the microcapsulation of allopurinol by the solvent evaporation method and the release of the drug from the microcapsules. The effect of concentration of poly(vinyl alcohol) (as a surfactant), molecular weight of ethyl cellulose and stirrer speed in the preparative method were studied. The effect of molecular weight of ethyl cellulose and particle size on drug release were also investigated. It has been found that the drug release is decreased with increasing molecular weight of polymer and increasing particle size.
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Affiliation(s)
- H Arabi
- Polymer Research Center of Iran, Tehran
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26
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Rao JK, Ramesh DV, Rao KP. Controlled release systems for proteins based on gelatin microspheres. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1995; 6:391-8. [PMID: 7841146 DOI: 10.1163/156856294x00383] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The preparation and characterization of biodegradable gelatin microspheres for the controlled release of peptides and proteins has been investigated. Bovine serum albumin (BSA) was chosen for incorporation into the gelatin microspheres and the spheres were characterized for the in vitro release of BSA and other properties. BSA was labelled with fluorescein isothiocyanate (FITC) for easy analysis. FITC-BSA was entrapped into the gelatin microspheres using a polymer dispersion technique developed in our earlier studies. The morphological characteristics of microspheres were analysed by optical and scanning electron microscopy (SEM). The optical and SEM photographs of FITC-BSA microspheres showed the solid spherical nature of the spheres. The entrapment efficiency of FITC-BSA was about 62%. The in vitro release pattern of FITC-BSA showed that 51% of the entrapped drug was released during the first day and the release followed approximate zero order kinetics from day 2 onwards. The total release of FITC-BSA lasted for about 8 days. SDS-PAGE analysis revealed that BSA was not degraded by this preparation of microspheres.
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Affiliation(s)
- J K Rao
- Biomaterials Laboratory, Central Leather Research Institute, Adyar, Madras, India
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27
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Arshady R. Microspheres for biomedical applications: preparation of reactive and labelled microspheres. Biomaterials 1993; 14:5-15. [PMID: 7678756 DOI: 10.1016/0142-9612(93)90015-t] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This review describes the synthesis and physico-chemical properties of reactive and labelled microspheres useful for biomedical applications. Preparation of microspheres with specific functional groups, fluorescent species, radionuclides and magnetite particles (Fe2O3) are discussed. Physico-chemical properties of microspheres, including surface charge and hydrophilicity/hydrophobicity, are also briefly covered.
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Affiliation(s)
- R Arshady
- Department of Chemistry, Imperial College of Science, Technology and Medicine, London, UK
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