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Karpova SG, Olkhov AA, Varyan IA, Popov AA, Iordanskii AL. Effect of Drug Encapsulation and Hydrothermal Exposure on the Structure and Molecular Dynamics of the Binary System Poly(3-hydroxybutyrate)-chitosan. Polymers (Basel) 2023; 15:polym15102260. [PMID: 37242835 DOI: 10.3390/polym15102260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/03/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
In this work, film materials based on binary compositions of poly-(3-hydroxybutyrate) (PHB) and chitosan with different ratios of polymer components in the range from 0/100 to 100/0 wt. % were studied. Using a combination of thermal (DSC) and relaxation (EPR) measurements, the influence of the encapsulation temperature of the drug substance (DS) of dipyridamole (DPD) and moderately hot water (at 70 °C) on the characteristics of the PHB crystal structure and the diffusion rotational mobility of the stable TEMPO radical in the amorphous regions of the PHB/chitosan compositions is shown. The low-temperature extended maximum on the DSC endotherms made it possible to obtain additional information about the state of the chitosan hydrogen bond network. This allowed us to determine the enthalpies of thermal destruction of these bonds. In addition, it is shown that when PHB and chitosan are mixed, significant changes are observed in the degree of crystallinity of PHB, degree of destruction of hydrogen bonds in chitosan, segmental mobility, sorption capacity of the radical, and the activation energy of rotational diffusion in the amorphous regions of the PHB/chitosan composition. The characteristic point of polymer compositions was found to correspond to the ratio of the components of the mixture 50/50%, for which the inversion transition of PHB from dispersed material to dispersion medium is assumed. Encapsulation of DPD in the composition leads to higher crystallinity and to a decrease in the enthalpy of hydrogen bond breaking, and it also slows down segmental mobility. Exposure to an aqueous medium at 70 °C is also accompanied by sharp changes in the concentration of hydrogen bonds in chitosan, the degree of PHB crystallinity, and molecular dynamics. The conducted research made it possible for the first time to conduct a comprehensive analysis of the mechanism of action of a number of aggressive external factors (such as temperature, water, and the introduced additive in the form of a drug) on the structural and dynamic characteristics of the PHB/chitosan film material at the molecular level. These film materials have the potential to serve as a therapeutic system for controlled drug delivery.
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Affiliation(s)
- S G Karpova
- Department of Biological and Chemical Physics of Polymers, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119334 Moscow, Russia
| | - A A Olkhov
- Department of Biological and Chemical Physics of Polymers, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119334 Moscow, Russia
- Academic Department of Innovational Materials and Technologies Chemistry, Plekhanov Russian University of Economics, 36 Stremyanny Lane, 117997 Moscow, Russia
| | - I A Varyan
- Department of Biological and Chemical Physics of Polymers, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119334 Moscow, Russia
- Academic Department of Innovational Materials and Technologies Chemistry, Plekhanov Russian University of Economics, 36 Stremyanny Lane, 117997 Moscow, Russia
| | - A A Popov
- Department of Biological and Chemical Physics of Polymers, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119334 Moscow, Russia
- Academic Department of Innovational Materials and Technologies Chemistry, Plekhanov Russian University of Economics, 36 Stremyanny Lane, 117997 Moscow, Russia
| | - A L Iordanskii
- N. N. Semenov Federal Research Center for Chemical Physics Academy of Science, 119991 Moscow, Russia
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Alba K, Kasapis S, Kontogiorgos V. Influence of pH on mechanical relaxations in high solids LM-pectin preparations. Carbohydr Polym 2015; 127:182-8. [PMID: 25965472 DOI: 10.1016/j.carbpol.2015.03.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 03/12/2015] [Accepted: 03/13/2015] [Indexed: 11/18/2022]
Abstract
The influence of pH on the mechanical relaxation of LM-pectin in the presence of co-solute has been investigated by means of differential scanning calorimetry, ζ-potential measurements and small deformation dynamic oscillation in shear. pH was found to affect the conformational properties of the polyelectrolyte altering its structural behavior. Cooling scans in the vicinity of the glass transition region revealed a remarkable change in the viscoelastic functions as the polyelectrolyte rearranges from extended (neutral pH) to compact conformations (acidic pH). This conformational rearrangement was experimentally observed to result in early vitrification at neutral pH values where dissociation of galacturonic acid residues takes place. Time-temperature superposition of the mechanical shift factors and theoretical modeling utilizing WLF kinetics confirmed the accelerated kinetics of glass transition in the extended pectin conformation at neutral pH. Determination of the relaxation spectra of the samples using spectral analysis of the master curves revealed that the relaxation of macromolecules occurs within ∼ 0.1s regardless of the solvent pH.
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Affiliation(s)
- K Alba
- Department of Biological Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK
| | - S Kasapis
- School of Applied Sciences, RMIT University, City Campus, Melbourne 3001, VIC, Australia
| | - V Kontogiorgos
- Department of Biological Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK.
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Altay F, Gunasekaran S. Mechanical spectra and calorimetric evaluation of gelatin–xanthan gum systems with high levels of co-solutes in the glassy state. Food Hydrocoll 2013. [DOI: 10.1016/j.foodhyd.2012.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ikeda S, Zhong Q. Polymer and colloidal models describing structure-function relationships. Annu Rev Food Sci Technol 2012; 3:405-24. [PMID: 22136127 DOI: 10.1146/annurev-food-022811-101250] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Colloidal and polymer systems are not only abundant in food but also useful for gaining insights into structure-function relationships of food. Colloid and polymer systems are composed of mesoscopic scale particles dispersed in a liquid. Because of a relatively small potential barrier against aggregation between mesoscopic particles, a small change in temperature, pH, or chemical compositions can trigger aggregation and induce remarkable changes in structure and function of colloidal and polymer systems. An aggregated state is not normally an equilibrium state but a kinetically trapped state also called a jammed state. Various kinetic factors in food processing, such as the rate of changes in temperature, water content, and chemical compositions, must be taken into account to establish a complete state diagram of colloid- and polymer-based food systems.
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Affiliation(s)
- Shinya Ikeda
- Department of Food Science and Technology, The University of Tennessee, Knoxville, Tennessee 37996, USA
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Syamaladevi RM, Barbosa-Cánovas GV, Schmidt SJ, Sablani SS. Influence of molecular weight on enthalpy relaxation and fragility of amorphous carbohydrates. Carbohydr Polym 2012. [DOI: 10.1016/j.carbpol.2011.11.088] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Jiang B, Kasapis S, Kontogiorgos V. Fundamental considerations in the effect of molecular weight on the glass transition of the gelatin/cosolute system. Biopolymers 2011; 97:303-10. [DOI: 10.1002/bip.22020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 12/06/2011] [Accepted: 12/07/2011] [Indexed: 11/12/2022]
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Jones DS, Tian Y, Abu-Diak O, Andrews GP. Pharmaceutical applications of dynamic mechanical thermal analysis. Adv Drug Deliv Rev 2011; 64:440-8. [PMID: 22192684 DOI: 10.1016/j.addr.2011.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/25/2011] [Accepted: 12/01/2011] [Indexed: 11/26/2022]
Abstract
The successful development of polymeric drug delivery and biomedical devices requires a comprehensive understanding of the viscoleastic properties of polymers as these have been shown to directly affect clinical efficacy. Dynamic mechanical thermal analysis (DMTA) is an accessible and versatile analytical technique in which an oscillating stress or strain is applied to a sample as a function of oscillatory frequency and temperature. Through cyclic application of a non-destructive stress or strain, a comprehensive understanding of the viscoelastic properties of polymers may be obtained. In this review, we provide a concise overview of the theory of DMTA and the basic instrumental/operating principles. Moreover, the application of DMTA for the characterization of solid pharmaceutical and biomedical systems has been discussed in detail. In particular we have described the potential of DMTA to measure and understand relaxation transitions and miscibility in binary and higher-order systems and describe the more recent applications of the technique for this purpose.
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Affiliation(s)
- David S Jones
- Queen's University Belfast, School of Pharmacy, The Drug Delivery and Biomaterials Group, Medical Biology Centre, 97 Lisburn Road, Belfast. BT9 7BL, Northern Ireland, UK
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Kaszyńska J, Hilczer B, Biskupski P. Segmental dynamics in poly(vinylidene fluoride) studied by dielectric, mechanical and nuclear magnetic resonance spectroscopies. Polym Bull (Berl) 2011. [DOI: 10.1007/s00289-011-0660-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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