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Fabrication of pH/Reduction Sensitive Polyethylene Glycol-Based Micelles for Enhanced Intracellular Drug Release. Pharmaceutics 2021; 13:pharmaceutics13091464. [PMID: 34575539 PMCID: PMC8470983 DOI: 10.3390/pharmaceutics13091464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 01/07/2023] Open
Abstract
At present, the drug is still difficult to release completely and quickly only with single stimulation. In order to promote the rapid release of polymeric micelles at tumor site, pH/reduction sensitive polymers (PCT) containing disulfide bonds and orthoester groups were synthesized. The PCT polymers can self-assemble in water and entrap doxorubicin to form drug-loaded micelles (DOX/PCT). In an in vitro drug release experiment, the cumulative release of DOX/PCT micelles in the simulated tumor microenvironment (pH 5.0 with GSH) reached (89.7 ± 11.7)% at 72 h, while it was only (16.7 ± 6.1)% in the normal physiological environment (pH 7.4 without GSH). In addition, pH sensitive DOX loaded micellar system (DOX/PAT) was prepared as a control. Furthermore, compared with DOX/PAT micelles, DOX/PCT micelles showed the stronger cytotoxicity against tumor cells to achieve an effective antitumor effect. After being internalized by clathrin/caveolin-mediated endocytosis and macropinocytosis, DOX/PCT micelles were depolymerized in intercellular acidic and a reductive environment to release DOX rapidly to kill tumor cells. Additionally, DOX/PCT micelles had a better inhibitory effect on tumor growth than DOX/PAT micelles in in vivo antitumor activity studies. Therefore, pH/reduction dual sensitive PCT polymers have great potential to be used as repaid release nanocarriers for intercellular delivery of antitumor drugs.
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Antibiotics Delivery for Treating Bone Infections. ADVANCES IN DELIVERY SCIENCE AND TECHNOLOGY 2014. [DOI: 10.1007/978-1-4614-9434-8_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Clarkin O, Wren A, Thornton R, Cooney J, Towler M. Antibacterial Analysis of a Zinc-based Glass Polyalkenoate Cement. J Biomater Appl 2010; 26:277-92. [DOI: 10.1177/0885328210364430] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Infection following surgery can result in significant pain and morbidity for patients undergoing vertebroplasty/kyphoplasty, and often results in revision surgery. This study focuses on the development of Al-free glass polyalkenoate cements (GPCs) based on 0.04SrO—0.12CaO—0.36ZnO—0.48SiO 2 glass, with the intent of optimizing their antibacterial efficacy by incorporating low—molecular-weight polyacrylic acids (PAA) and trisodium citrate (TSC), and evaluating the resultant GPCs against bacteria relevant to spinal infections, P. aeruginosa and E. coli. Ion-release profiles were determined for the GPC formulation containing E6 PAA (Cement A) and E7 PAA (Cement B), and Zn, Na, and Sr release was recorded over 1, 7, and 30 days. Inhibition was found in E. coli at each time period (0—30 days) and this generally decreased with exposure time in water. The largest GPC inhibition zones were produced by Cement A (6 mm); however the control material Simplex P + tobramycin produced much higher inhibition zones (11 mm). When testing the GPC against P. aeruginosa, inhibition was only present at the 0-day time period. Simplex P + tobramycin was found to produce inhibition at each time frame. Analysis of the agar from the inhibition zone of the E. coli test revealed that there is a significant change in Zn concentration as compared to a control agar specimen, which suggests that Zn release is responsible for the antibacterial effect of the GPCs.
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Affiliation(s)
- Owen Clarkin
- Materials and Surface Science Institute, University of Limerick Limerick, Republic of Ireland
| | - Anthony Wren
- Inamori School of Engineering, Alfred University, NY, USA,
| | - Roibeard Thornton
- Department of Life Sciences, University of Limerick, Limerick Republic of Ireland
| | - Jakki Cooney
- Department of Life Sciences, University of Limerick, Limerick Republic of Ireland
| | - Mark Towler
- Inamori School of Engineering, Alfred University, NY, USA
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Domingo C, Vega A, Fanovich MA, Elvira C, Subra P. Behavior of poly(methyl methacrylate)-based systems in supercritical CO2 and CO2 plus cosolvent: Solubility measurements and process assessment. J Appl Polym Sci 2003. [DOI: 10.1002/app.13097] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zhang M, Yang Z, Chow LL, Wang CH. Simulation of Drug Release from Biodegradable Polymeric Microspheres with Bulk and Surface Erosions. J Pharm Sci 2003; 92:2040-56. [PMID: 14502543 DOI: 10.1002/jps.10463] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
New models are developed to account for the kinetics of drug release from porous, biodegradable polymeric microspheres under the schemes of bulk erosion and surface erosion of the polymer matrix, respectively. Three mechanisms of drug release, namely, drug diffusion, drug dissolution, and polymer erosion jointly govern the overall release process. For bulk erosion, the model incorporates an erosion term into the dissolution and diffusion equation and is solved numerically for various boundary conditions. Dissolution and erosion are defined in the model by introducing three equations which take into account the drug concentration in the liquid phase, virtual solid phase, and effective solid phase. For surface erosion, drug concentrations in liquid and solid phases are defined and a substitution is introduced to convert the moving-boundary problem to a fixed-boundary problem. The resulting differential equations are solved simultaneously to obtain the concentration profile in the liquid and solid phases, respectively. Numerical solutions are provided to illustrate the effects of drug dissolution constant, drug diffusion coefficient, and erosion rate constant. In general, increasing erosion rate, diffusivity, dissolution, and decreasing particle radius enhance the drug release rate. Predictions from the models are also compared with experimental data to verify their validity and possible improvements are proposed.
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Affiliation(s)
- Mingping Zhang
- Department of Chemical and Environmental Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576
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Deng JS, Li L, Tian Y, Ginsburg E, Widman M, Myers A. In vitro characterization of polyorthoester microparticles containing bupivacaine. Pharm Dev Technol 2003; 8:31-8. [PMID: 12665195 DOI: 10.1081/pdt-120017521] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Laboratory-scale spray-congealing equipment was utilized to fabricate injectable microparticles consisting of polyorthoester and bupivacaine. Operating conditions for the spray-congealing process were optimized to produce microparticles with the desired shape and particle size to yield acceptable syringeability and injectability. Characterizations were performed to determine the chemico-physical properties of polyorthoester before and after microparticle fabrication. Microparticles with different drug loadings and comparable particle sizes were produced, and their in vitro drug-release profiles were determined. The in vitro drug release of microparticles with a high drug loading was markedly faster than those with a low drug loading. This is partially attributed to a more significant initial burst-drug release of the microparticles with a high drug loading. The microparticles have demonstrated the potential to be used for long-acting postsurgery pain management by local injection.
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Affiliation(s)
- Jone-Shin Deng
- Advanced Drug Delivery, Hospital Products Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
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Sivakuma M, Rao KP. In vitro release of ibuprofen and gentamicin from PMMA functional microspheres. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2002; 13:111-26. [PMID: 12022744 DOI: 10.1163/156856202317414311] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Drug-containing microspheres based on synthetic polymers such as poly(methyl methacrylate) (PMMA) and PMMA derivatives are known for their medical applications, particularly for hard tissue repair and regeneration. In our earlier work, we have reported that the synthesis of PMMA and carboxyl group-containing PMMA functional (PMMA-F) microspheres and these microspheres were fully characterized by various techniques. In the present investigation, an attempt was made to prepare drug-containing PMMA (without carboxylic functional groups) and PMMA-F (with carboxylic functional groups) microspheres by solvent evaporation technique. The presence of characteristic groups in the drug-containing PMMA and PMMA-F microspheres was confirmed using 1H-FT-NMR spectroscopy. Equilibrium swelling experiments of both microspheres was carried out in pH 7.4 phosphate buffer and pH 1.2 gastric medium. PMMA-F microspheres were able to float in the pH 1.2 and 7.4 media, whereas PMMA microspheres settled in both. Optical and scanning electron micrographs indicated that the microspheres are spherical and porous in nature. The carboxylic groups of PMMA-F microspheres were coupled with amino groups of gentamicin using 1-ethyl-3(3-dimethylpropyl) carbodiamide as coupling agent, whereas in the case of PMMA microspheres, the gentamicin was incorporated in the porous site of the microspheres. The ibuprofen drug was incorporated in the porous site of PMMA and PMMA-F microspheres. The cumulative in vitro release profiles of gentamicin and ibuprofen from PMMA and PMMA-F microspheres were performed in PBS pH 7.4 at 37 degrees C. It shows that gentamicin containing PMMA-F microspheres releases the drug ones a longer period compared to PMMA microspheres.
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Affiliation(s)
- M Sivakuma
- Biomaterials Division, Central Leather Research Institute, Adyar, Chennai, India.
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Einmahl S, Capancioni S, Schwach-Abdellaoui K, Moeller M, Behar-Cohen F, Gurny R. Therapeutic applications of viscous and injectable poly(ortho esters). Adv Drug Deliv Rev 2001; 53:45-73. [PMID: 11733117 DOI: 10.1016/s0169-409x(01)00220-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Poly(ortho esters) (POE) are hydrophobic and bioerodible polymers that have been investigated for pharmaceutical use since the early 1970s. Among the four described generations of POE, the third (POE III) and fourth (POE IV) are promising viscous and injectable materials which have been investigated in numerous biomedical applications. POE III has been extensively studied for ophthalmic drug delivery, it presents an excellent biocompatibility and is currently being investigated as a vehicle for sustained drug delivery to treat diseases of the posterior segment of the eye. POE IV is distinguishable by a highly reproducible and controlled synthesis, a higher hydrophobicity, and an excellent biocompatibility. It is currently under development for a variety of applications, such as ocular delivery, periodontal disease treatment and applications in veterinary medicine. This review will also focus on new perspectives for this promising family of polymers, such as guided tissue regeneration, treatment of osteoarthritis, as well as peptide and protein delivery.
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Affiliation(s)
- S Einmahl
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmacy, University of Geneva, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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Karjalainen T, Rich J, Seppälä J. Release of model compounds from modified lactone copolymers. J Appl Polym Sci 2001. [DOI: 10.1002/app.1647] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Schwach-Abdellaoui K, Heller J, Gurny R. Synthesis and characterization of self-catalyzed poly(ortho-esters) based on decanediol and decanediol-lactate. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1999; 10:375-89. [PMID: 10189105 DOI: 10.1163/156856299x00432] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The synthesis of poly(ortho-esters) (POEs) containing lactic acid dimers in the polymer backbone for possible use in controlled drug release applications is described. These autocatalyzed POEs are prepared by the acid catalyzed condensation of 3,9-diethylidene-2,4,8,10-tetraoxaspiro(5,5)undecane with diols to produce linear polymers. The diols used were a mixture of decanediol-lactate and decanediol in various molar ratio to produce polymers with different lactic acid contents. Polymer structures were confirmed by 13C NMR, 1H NMR, and FT-IR and physico-chemical properties, such as molecular weights, glass transition temperatures and viscoelastic behavior, were also determined.
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Abstract
For a long time, subcutaneous implantable drug pellets using nondegradable polymers have been used for long-term, continuous drug administration. The procedure requires surgical implantation and removal of the drug-containing devices or polymeric matrices, which has a significant negative impact on the acceptability of the product candidate. In addition, the release profile from such devices is neither constant nor readily controlled in terms of precision of rate of release and duration of action. These facts have led to the research and development of novel, controllable, nonirritating, noncarcinogenic, biocompatible, and bioabsorbable drug delivery systems for overcoming the drawbacks of nondegradable implantable pellets for prolonged continuous release. Biodegradable implantable systems release the drug over a long period of time with simultaneous or subsequent degradation in the tissue of the polymer to harmless constituents, thus avoiding removal once the therapy is complete. This approach has considerably improved patient acceptability and patient compliance. Various bioabsorbable polymers have been evaluated for controlled implantable drug delivery, including hydrogels, copolymers of polylactic and polyglycolic acids, polylactic acid, poly(orthoesters), polyanhydrides, poly(E-caprolactone), and polyurethanes. Their characteristics have been studied using a variety of drugs, like anticancer agents, hormone agonists and antagonists, nonsteroidal anti-inflammatory agents, neuroleptics, contraceptives, and others. The present paper describes the current research on implantable therapeutic systems, the bioabsorbable polymers, and the biologically active agents being used in this approach.
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Affiliation(s)
- V R Sinha
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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