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Curti F, Serafim A, Olaret E, Dinescu S, Samoila I, Vasile BS, Iovu H, Lungu A, Stancu IC, Marinescu R. Development of Biocomposite Alginate-Cuttlebone-Gelatin 3D Printing Inks Designed for Scaffolds with Bone Regeneration Potential. Mar Drugs 2022; 20:670. [PMID: 36354993 PMCID: PMC9694341 DOI: 10.3390/md20110670] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 10/29/2023] Open
Abstract
Fabrication of three-dimensional (3D) scaffolds using natural biomaterials introduces valuable opportunities in bone tissue reconstruction and regeneration. The current study aimed at the development of paste-like 3D printing inks with an extracellular matrix-inspired formulation based on marine materials: sodium alginate (SA), cuttlebone (CB), and fish gelatin (FG). Macroporous scaffolds with microporous biocomposite filaments were obtained by 3D printing combined with post-printing crosslinking. CB fragments were used for their potential to stimulate biomineralization. Alginate enhanced CB embedding within the polymer matrix as confirmed by scanning electron microscopy (ESEM) and micro-computer tomography (micro-CT) and improved the deformation under controlled compression as revealed by micro-CT. SA addition resulted in a modulation of the bulk and surface mechanical behavior, and lead to more elongated cell morphology as imaged by confocal microscopy and ESEM after the adhesion of MC3T3-E1 preosteoblasts at 48 h. Formation of a new mineral phase was detected on the scaffold's surface after cell cultures. All the results were correlated with the scaffolds' compositions. Overall, the study reveals the potential of the marine materials-containing inks to deliver 3D scaffolds with potential for bone regeneration applications.
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Affiliation(s)
- Filis Curti
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
- Zentiva S.A., 50 Theodor Pallady, 032266 Bucharest, Romania
| | - Andrada Serafim
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
| | - Elena Olaret
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
| | - Sorina Dinescu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania
- Research Institute of the University of Bucharest, 050663 Bucharest, Romania
| | - Iuliana Samoila
- Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania
| | - Bogdan Stefan Vasile
- National Research Center for Micro and Nanomaterials, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 060042 Bucharest, Romania
- National Research Center for Food Safety, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 060042 Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
- Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
| | - Izabela Cristina Stancu
- Advanced Polymer Materials Group, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania
| | - Rodica Marinescu
- Faculty of Medicine, Department of Orthopedics, University of Medicine and Pharmacy “Carol Davila” Bucharest, Eroii Sanitari Street No. 8, District 5, 050474 Bucharest, Romania
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Cernencu AI, Dinu AI, Stancu IC, Lungu A, Iovu H. Nanoengineered biomimetic hydrogels: A major advancement to fabricate 3D-printed constructs for regenerative medicine. Biotechnol Bioeng 2021; 119:762-783. [PMID: 34961918 DOI: 10.1002/bit.28020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/09/2021] [Accepted: 12/21/2021] [Indexed: 11/08/2022]
Abstract
Nanostructured compounds already validated as performant reinforcements for biomedical applications together with different fabrication strategies have been often used to channel the biophysical and biochemical features of hydrogel networks. Ergo, a wide array of nanostructured compounds has been employed as additive materials integrated with hydrophilic networks based on naturally-derived polymers to produce promising scaffolding materials for specific fields of regenerative medicine. To date, nanoengineered hydrogels are extensively explored in (bio)printing formulations, representing the most advanced designs of hydrogel (bio)inks able to fabricate structures with improved mechanical properties and high print fidelity along with a cell-interactive environment. The development of printing inks comprising organic-inorganic hybrid nanocomposites is in full ascent as the impact of a small amount of nanoscale additive does not translate only in improved physicochemical and biomechanical properties of bioink. The biopolymeric nanocomposites may even exhibit additional particular properties engendered by nano-scale reinforcement such as electrical conductivity, magnetic responsiveness, antibacterial or antioxidation properties. The present review focus on hydrogels nanoengineered for 3D printing of biomimetic constructs, with particular emphasis on the impact of the spatial distribution of reinforcing agents (0D, 1D, 2D). Here, a systematic analysis of the naturally-derived nanostructured inks is presented highlighting the relationship between relevant length scales and size effects that influence the final properties of the hydrogels designed for regenerative medicine. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Alexandra I Cernencu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania
| | - Andreea I Dinu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania
| | - Izabela C Stancu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061, Bucharest, Romania.,Academy of Romanian Scientists, 54 Splaiul Independentei, 050094, Bucharest, Romania
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Cernencu AI, Lungu A, Dragusin DM, Stancu IC, Dinescu S, Balahura LR, Mereuta P, Costache M, Iovu H. 3D Bioprinting of Biosynthetic Nanocellulose-Filled GelMA Inks Highly Reliable for Soft Tissue-Oriented Constructs. Materials (Basel) 2021; 14:ma14174891. [PMID: 34500980 PMCID: PMC8432727 DOI: 10.3390/ma14174891] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 11/21/2022]
Abstract
Bioink-formulations based on gelatin methacrylate combined with oxidized cellulose nanofibrils are employed in the present study. The parallel investigation of the printing performance, morphological, swelling, and biological properties of the newly developed hydrogels was performed, with inks prepared using methacrylamide-modified gelatins of fish or bovine origin. Scaffolds with versatile and well-defined internal structure and high shape fidelity were successfully printed due to the high viscosity and shear-thinning behavior of formulated inks and then photo-crosslinked. The biocompatibility of 3D-scaffolds was surveyed using human adipose stem cells (hASCs) and high viability and proliferation rates were obtained when in contact with the biomaterial. Furthermore, bioprinting tests were performed with hASCs embedded in the developed formulations. The results demonstrated that the designed inks are a versatile toolkit for 3D bioprinting and further show the benefits of using fish-derived gelatin for biofabrication.
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Affiliation(s)
- Alexandra I. Cernencu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.I.C.); (D.M.D.); (I.C.S.); (H.I.)
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.I.C.); (D.M.D.); (I.C.S.); (H.I.)
- Correspondence:
| | - Diana M. Dragusin
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.I.C.); (D.M.D.); (I.C.S.); (H.I.)
| | - Izabela C. Stancu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.I.C.); (D.M.D.); (I.C.S.); (H.I.)
| | - Sorina Dinescu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (S.D.); (L.R.B.); (M.C.)
| | - Liliana R. Balahura
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (S.D.); (L.R.B.); (M.C.)
| | - Paul Mereuta
- Horia Hulubei—National Institute for Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului Street, 077125 Magurele, Romania;
| | - Marieta Costache
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (S.D.); (L.R.B.); (M.C.)
| | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.I.C.); (D.M.D.); (I.C.S.); (H.I.)
- Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest, Romania
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Balahura LR, Dinescu S, Balaș M, Cernencu A, Lungu A, Vlăsceanu GM, Iovu H, Costache M. Cellulose Nanofiber-Based Hydrogels Embedding 5-FU Promote Pyroptosis Activation in Breast Cancer Cells and Support Human Adipose-Derived Stem Cell Proliferation, Opening New Perspectives for Breast Tissue Engineering. Pharmaceutics 2021; 13:pharmaceutics13081189. [PMID: 34452150 PMCID: PMC8400202 DOI: 10.3390/pharmaceutics13081189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022] Open
Abstract
The structure and biocompatibility analysis of a hydrogel based on cellulose nanofibers (CNFs) combined with alginate/pectin (A.CNF or P.CNF) and enriched with 1% or 5% 5-FU revealed more favorable properties for the cellular component when pectin was dispersed within CNFs. 5-Fluorouracil (5-FU) is an antimetabolite fluoropyrimidine used as antineoplastic drug for the treatment of multiple solid tumors. 5-FU activity leads to caspase-1 activation, secretion and maturation of interleukins (IL)-1, IL-18 and reactive oxygen species (ROS) generation. Furthermore, the effects of embedding 5-FU in P.CNF were explored in order to suppress breast tumor cell growth and induce inflammasome complex activation together with extra- and intracellular ROS generation. Exposure of tumor cells to P.CNF/5-FU resulted in a strong cytotoxic effect, an increased level of caspase-1 released in the culture media and ROS production—the latter directly proportional to the concentration of anti-tumor agent embedded in the scaffolds. Simultaneously, 5-FU determined the increase of p53 and caspase-1 expressions, both at gene and protein levels. In conclusion, P.CNF/5-FU scaffolds proved to be efficient against breast tumor cells growth due to pyroptosis induction. Furthermore, biocompatibility and the potential to support human adipose-derived stem cell growth were demonstrated, suggesting that these 3D systems could be used in soft tissue reconstruction post-mastectomy.
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Affiliation(s)
- Liliana-Roxana Balahura
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (L.-R.B.); (M.B.); (M.C.)
- Department of Immunology, National Institute for Research and Development in Biomedical Pathology and Biomedical Sciences “Victor Babes”, 050096 Bucharest, Romania
| | - Sorina Dinescu
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (L.-R.B.); (M.B.); (M.C.)
- Research Institute of University of Bucharest, 050107 Bucharest, Romania
- Correspondence: ; Tel.: +40-724511587
| | - Mihaela Balaș
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (L.-R.B.); (M.B.); (M.C.)
| | - Alexandra Cernencu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.C.); (A.L.); (G.M.V.); (H.I.)
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.C.); (A.L.); (G.M.V.); (H.I.)
| | - George Mihail Vlăsceanu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.C.); (A.L.); (G.M.V.); (H.I.)
| | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (A.C.); (A.L.); (G.M.V.); (H.I.)
| | - Marieta Costache
- Department of Biochemistry and Molecular Biology, University of Bucharest, 050095 Bucharest, Romania; (L.-R.B.); (M.B.); (M.C.)
- Research Institute of University of Bucharest, 050107 Bucharest, Romania
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Olăreț E, Drăgușin DM, Serafim A, Lungu A, Șelaru A, Dobranici A, Dinescu S, Costache M, Boerașu I, Vasile BȘ, Steinmüller-Nethl D, Iovu H, Stancu IC. Electrospinning Fabrication and Cytocompatibility Investigation of Nanodiamond Particles-Gelatin Fibrous Tubular Scaffolds for Nerve Regeneration. Polymers (Basel) 2021; 13:polym13030407. [PMID: 33514051 PMCID: PMC7865256 DOI: 10.3390/polym13030407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
This paper reports the electrospinning fabrication of flexible nanostructured tubular scaffolds, based on fish gelatin (FG) and nanodiamond nanoparticles (NDs), and their cytocompatibility with murine neural stem cells. The effects of both nanofiller and protein concentration on the scaffold morphology, aqueous affinity, size modification at rehydration, and degradation are assessed. Our findings indicate that nanostructuring with low amounts of NDs may modify the fiber properties, including a certain regional parallel orientation of fiber segments. NE-4C cells form dense clusters that strongly adhere to the surface of FG50-based scaffolds, while also increasing FG concentration and adding NDs favor cellular infiltration into the flexible fibrous FG70_NDs nanocomposite. This research illustrates the potential of nanostructured NDs-FG fibers as scaffolds for nerve repair and regeneration. We also emphasize the importance of further understanding the effect of the nanofiller-protein interphase on the microstructure and properties of electrospun fibers and on cell-interactivity.
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Affiliation(s)
- Elena Olăreț
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
| | - Diana-Maria Drăgușin
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
| | - Andrada Serafim
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
| | - Aida Șelaru
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania; (A.Ș.); (A.D.); (S.D.); (M.C.)
- Department of Immunology, National Institute for Research and Development in Biomedical Pathology and Biomedical Sciences “Victor Babes”, 050096 Bucharest, Romania
| | - Alexandra Dobranici
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania; (A.Ș.); (A.D.); (S.D.); (M.C.)
| | - Sorina Dinescu
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania; (A.Ș.); (A.D.); (S.D.); (M.C.)
- The Research Institute of the University of Bucharest, 050663 Bucharest, Romania
| | - Marieta Costache
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania; (A.Ș.); (A.D.); (S.D.); (M.C.)
- The Research Institute of the University of Bucharest, 050663 Bucharest, Romania
| | - Iulian Boerașu
- National Research Center for Micro and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 060042 Bucharest, Romania; (I.B.); (B.Ș.V.)
| | - Bogdan Ștefan Vasile
- National Research Center for Micro and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 060042 Bucharest, Romania; (I.B.); (B.Ș.V.)
- National Research Center for Food Safety, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 060042 Bucharest, Romania
| | | | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
| | - Izabela-Cristina Stancu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, 011061 Bucharest, Romania; (E.O.); (D.-M.D.); (A.S.); (A.L.); (H.I.)
- Correspondence:
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Cernencu AI, Lungu A, Stancu IC, Serafim A, Heggset E, Syverud K, Iovu H. Bioinspired 3D printable pectin-nanocellulose ink formulations. Carbohydr Polym 2019; 220:12-21. [DOI: 10.1016/j.carbpol.2019.05.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 11/28/2022]
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Lungu A, Ghitman J, Cernencu AI, Serafim A, Florea NM, Vasile E, Iovu H. POSS-containing hybrid nanomaterials based on thiol-epoxy click reaction. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.05.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Florea NM, Damian CM, Ionescu C, Lungu A, Vasile E, Iovu H. Designing of polyhedral oligomeric silsesquioxane (POSS)-based dithiol/dimethacrylate nano-hybrids. Polym Bull (Berl) 2017. [DOI: 10.1007/s00289-017-2242-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Cecoltan S, Stancu IC, Drăguşin DM, Serafim A, Lungu A, Ţucureanu C, Caraş I, Tofan VC, Sălăgeanu A, Vasile E, Mallet R, Chappard D, Coman C, Istodorescu M, Iovu H. Nanocomposite particles with improved microstructure for 3D culture systems and bone regeneration. J Mater Sci Mater Med 2017; 28:153. [PMID: 28861646 DOI: 10.1007/s10856-017-5966-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/19/2017] [Indexed: 06/07/2023]
Abstract
Nano-apatite and gelatin-alginate hydrogel microparticles have been prepared by a one-step synthesis combined with electrostatic bead generation, for the reconstruction of bone defects. Based on the analysis of bone composition, architecture and embryonic intramembranous ossification, a bio-inspired fabrication has been developed. Accordingly, the mineral phase has been in situ synthesized, calcifying the hydrogel matrix while the latter was crosslinked, finally generating microparticles that can assemble into a bone defect to ensure interconnected pores. Although nano-apatite-biopolymer composites have been widely investigated, microstructural optimization to provide improved distribution and stability of the mineral is rarely achieved. The optimization of the developed method progressively resulted in two types of formulations (15P and 7.5P), with 15 and 7.5 (wt%) phosphate content in the initial precursor. The osteolytic potential was investigated using differentiated macrophages. A commercially available calcium phosphate bone graft substitute (Eurocer 400) was incorporated into the hydrogel, and the obtained composites were in vitro tested for comparison. The cytocompatibility of the microparticles was studied with mouse osteoblast-like cell line MC3T3-E1. Results indicated the best in vitro performance have been obtained for the sample loaded with 7.5P. Preliminary evaluation of biocompatibility into a critical size (3 mm) defect in rabbits showed that 7.5P nanocomposite is associated with newly formed bone in the proximity of the microparticles, after 28 days.
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Affiliation(s)
- Sergiu Cecoltan
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
| | - Izabela-Cristina Stancu
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania.
- Faculty of Medical Engineering, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania.
| | - Diana Maria Drăguşin
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
- Faculty of Medical Engineering, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
| | - Andrada Serafim
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
- Faculty of Medical Engineering, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
| | - Cătălin Ţucureanu
- "Cantacuzino" National Institute for Research, Cantacuzino" National Institute for Research, 103 Splaiul Independentei, 050096, Bucharest, Romania
| | - Iuliana Caraş
- "Cantacuzino" National Institute for Research, Cantacuzino" National Institute for Research, 103 Splaiul Independentei, 050096, Bucharest, Romania
| | - Vlad Constantin Tofan
- "Cantacuzino" National Institute for Research, Cantacuzino" National Institute for Research, 103 Splaiul Independentei, 050096, Bucharest, Romania
| | - Aurora Sălăgeanu
- "Cantacuzino" National Institute for Research, Cantacuzino" National Institute for Research, 103 Splaiul Independentei, 050096, Bucharest, Romania
| | - Eugeniu Vasile
- Faculty of Applied Chemistry and Materials Science, Department of Science and Engineering of Oxide Materials and Nanomaterials, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
| | - Romain Mallet
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LabCom NextBone, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, Université d'Angers, 49933 ANGERS, Cedex, France
| | - Daniel Chappard
- GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LabCom NextBone, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, Université d'Angers, 49933 ANGERS, Cedex, France
- SCIAM, Service Commun d'Imagerie et Analyses Microscopiques, IRIS-IBS Institut de Biologie en Santé, CHU d'Angers, Université d'Angers, 49933 ANGERS, Cedex, France
| | - Cristin Coman
- "Cantacuzino" National Institute for Research, Cantacuzino" National Institute for Research, 103 Splaiul Independentei, 050096, Bucharest, Romania
| | - Mircea Istodorescu
- S.C. Medical Ortovit S.R.L., 8 Miron Costin, Sector 1, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, 1-7 Gheorghe Polizu Street, Sector 1, 011061, Bucharest, Romania
- Academy of Romanian Scientists, 54 Splaiul Independentei, Bucharest, 050094, Romania
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Abstract
Lately, renewable resources received great attention in the macromolecular compounds area, regarding the design of the monomers and polymers with different applications. In this study the capacity of several modified vegetable oil-based monomers to build competitive hybrid networks was investigate, taking into account thermal and mechanical behavior of the designed materials. In order to synthesize such competitive nanocomposites, the selected renewable raw material, camelina oil, was employed due to the non-toxicity and biodegradability behavior. General properties of epoxidized camelina oil-based materials were improved by loading of different types of organic-inorganic hybrid compounds – polyhedral oligomeric silsesquioxane (POSS) bearing one (POSS1Ep) or eight (POSS8Ep) epoxy rings on the cages. In order to identify the chemical changes occurring after the thermal curing reactions, FT-IR spectrometry was employed. The new synthesized nanocomposites based on epoxidized camelina oil (ECO) were characterized by dynamic mechanical analyze and thermogravimetric analyze. The morphology of the ECO-based materials was investigate by scanning electron microscopy and supplementary information regarding the presence of the POSS compounds were establish by energy dispersive X-ray analysis and X-ray photoelectron spectroscopy. The smooth materials without any separation phase indicates a well dispersion of the Si–O–Si cages within the organic matrix and the incorporation of this hybrid compounds into the ECO network demonstrates to be a well strategy to improve the thermal and mechanical properties, simultaneously.
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Affiliation(s)
- Brindusa Balanuca
- Department of Bioresources and Polymer Science, Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Raluca Stan
- Department of Organic Chemistry, University Politehnica of Bucharest, Bucharest, Romania
| | - Adriana Lungu
- Department of Bioresources and Polymer Science, Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Eugeniu Vasile
- Department of Bioresources and Polymer Science, Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Horia Iovu
- Department of Bioresources and Polymer Science, Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania.,Academy of Romanian Scientists, Bucharest, Romania
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11
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Florea NM, Lungu A, Balanuca B, Badica P, Craciun L, Damian CM, Enculescu M, Ionescu C, Tihan G, Iovu H. Effect of polyhedral oligomeric silsesquioxane nanoreinforcement on the properties of epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) nanocomposites. HIGH PERFORM POLYM 2016. [DOI: 10.1177/0954008315595447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article reports the synthesis and characterization of several types of organic–inorganic nanocomposites based on epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) reinforced with 2, 5, or 10 wt% polyhedral oligomeric silsesquioxanes (POSS) bearing one glycidyl (1GE-POSS) or eight glycidyl(8GE-POSS) groups. The morphological features of the studied samples were established through atomic force microscopy, contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy, and it was demonstrated that 8GE-POSS is well dispersed within the polymer matrix, while 1GE-POSS exhibits a high tendency to form aggregates. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) measurements are used to follow the curing behavior and to study the polymerization kinetics of epoxy groups. As evidenced by DSC and FTIR results, the inclusion of 8GE-POSS within the polymer matrix leads to a lower epoxy polymerization rate of the resulted nanocomposites than those reinforced with 1GE-POSS. The dynamic mechanical analysis results revealed that the thermomechanical properties are gradually improved with increasing of 8GE-POSS content due to the higher cross-linking density.
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Affiliation(s)
- Nicoleta M Florea
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Brindusa Balanuca
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Petre Badica
- National Institute of Materials Physics, Magurele, Romania
| | - Liviu Craciun
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Celina M Damian
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | | | - Cristina Ionescu
- Horia Hulubei – National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Romania
| | - Gratiela Tihan
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, University Politehnica of Bucharest, Bucharest, Romania
- Academy of Romanian Scientists, Bucharest, Romania
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Peruzzi L, Gianoglio B, Pecoraro C, Alessandrella A, Murer L, Benetti E, Deschenes G, Materassi M, Gallo P, Lugani F, Ghiggeri G, Spasojevic Dimitrieva B, Jankauskiene A, Mizerska-Wasiak M, Lungu A, Coppo R. TO044A EUROPEAN REGISTRY OF HENOCH SCHOENLEINPURPURA NEPHRITIS IN CHILDREN TO DETECT RISK FACTORS FOR PROGRESSION. Nephrol Dial Transplant 2016. [DOI: 10.1093/ndt/gfw151.03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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13
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Mangaloiu D, Dumitru M, Punga A, Lungu A. Cardiovascular disease among Romani people in Romania. Eur J Public Health 2015. [DOI: 10.1093/eurpub/ckv176.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Affiliation(s)
- Adriana Lungu
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1-7 Gh. Polizu Street Bucharest 011061 Romania
| | - Nicoleta Mihaela Florea
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1-7 Gh. Polizu Street Bucharest 011061 Romania
- Horia Hulubei - National Institute for Physics and Nuclear Engineering (IFIN-HH); 30 Reactorului Street Magurele 077125 Romania
| | - Mihaela Manea
- Horia Hulubei - National Institute for Physics and Nuclear Engineering (IFIN-HH); 30 Reactorului Street Magurele 077125 Romania
| | - Eugeniu Vasile
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1-7 Gh. Polizu Street Bucharest 011061 Romania
| | - Horia Iovu
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1-7 Gh. Polizu Street Bucharest 011061 Romania
- Academy of Romanian Scientists; 54 Splaiul Independentei Bucharest 050094 Romania
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15
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Serafim A, Cecoltan S, Lungu A, Vasile E, Iovu H, Stancu IC. Electrospun fish gelatin fibrous scaffolds with improved bio-interactions due to carboxylated nanodiamond loading. RSC Adv 2015. [DOI: 10.1039/c5ra14361f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This work emphasizes the potential of COOH-functionalized nanodiamond (NDs) particles to improve bio-interactions when embedded into fish gelatin electrospun fibers.
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Affiliation(s)
- A. Serafim
- Advanced Polymer Materials Group
- Faculty of Applied Chemistry and Materials Science
- University Politehnica of Bucharest
- 011061 Bucharest
- Romania
| | - S. Cecoltan
- Advanced Polymer Materials Group
- Faculty of Applied Chemistry and Materials Science
- University Politehnica of Bucharest
- 011061 Bucharest
- Romania
| | - A. Lungu
- Advanced Polymer Materials Group
- Faculty of Applied Chemistry and Materials Science
- University Politehnica of Bucharest
- 011061 Bucharest
- Romania
| | - E. Vasile
- University Politehnica of Bucharest
- Faculty of Applied Chemistry and Materials Science
- Department of Science and Engineering of Oxide Materials and Nanomaterials
- 011061 Bucharest
- Romania
| | - H. Iovu
- Advanced Polymer Materials Group
- Faculty of Applied Chemistry and Materials Science
- University Politehnica of Bucharest
- 011061 Bucharest
- Romania
| | - I. C. Stancu
- Advanced Polymer Materials Group
- Faculty of Applied Chemistry and Materials Science
- University Politehnica of Bucharest
- 011061 Bucharest
- Romania
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16
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Balanuca B, Lungu A, Conicov I, Stan R, Vasile E, Vuluga DM, Iovu H. Novel bio-based IPNs obtained by simultaneous thermal polymerization of flexible methacrylate network based on a vegetable oil and a rigid epoxy. POLYM ADVAN TECHNOL 2014. [DOI: 10.1002/pat.3413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Brindusa Balanuca
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Romania
- Department of Organic Chemistry; University Politehnica of Bucharest; Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Romania
| | - Iulia Conicov
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Romania
| | - Raluca Stan
- Department of Organic Chemistry; University Politehnica of Bucharest; Romania
| | - Eugeniu Vasile
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Romania
| | - Dumitru Mircea Vuluga
- “Costin D. Nenitzescu” Center for Organic Chemistry of the Romanian Academy; Bucharest Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Romania
- Academy of Romanian Scientists
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17
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Lungu A, Wild JM, Capener D, Kiely DG, Swift AJ, Hose DR. MRI model-based non-invasive differential diagnosis in pulmonary hypertension. J Biomech 2014; 47:2941-7. [PMID: 25145313 DOI: 10.1016/j.jbiomech.2014.07.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 07/01/2014] [Accepted: 07/14/2014] [Indexed: 11/30/2022]
Abstract
Pulmonary hypertension(PH) is a disorder characterised by increased mean pulmonary arterial pressure. Currently, the diagnosis of PH relies upon measurements taken during invasive right heart catheterisation (RHC). This paper describes a process to derive diagnostic parameters using only non-invasive methods based upon MRI imaging alone. Simultaneous measurements of main pulmonary artery (MPA) anatomy and flow are interpreted by 0D and 1D mathematical models, in order to infer the physiological status of the pulmonary circulation. Results are reported for 35 subjects, 27 of whom were patients clinically investigated for PH and eight of whom were healthy volunteers. The patients were divided into 3 sub-groups according to the severity of the disease state, one of which represented a negative diagnosis (NoPH), depending on the results of the clinical investigation, which included RHC and complementary MR imaging. Diagnostic indices are derived from two independent mathematical models, one based on the 1D wave equation and one based on an RCR Windkessel model. Using the first model it is shown that there is an increase in the ratio of the power in the reflected wave to that in the incident wave (Wpb/Wptotal) according to the classification of the disease state. Similarly, the second model shows an increase in the distal resistance with the disease status. The results of this pilot study demonstrate that there are statistically significant differences in the parameters derived from the proposed models depending on disease status, and thus suggest the potential for development of a non-invasive, image-based diagnostic test for pulmonary hypertension.
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Affiliation(s)
- A Lungu
- University of Sheffield, Cardiovascular Science Department, Sheffield, South Yorkshire, UK.
| | - J M Wild
- University of Sheffield, Cardiovascular Science Department, Sheffield, South Yorkshire, UK; INSIGNEO-Institute for in silico Medicine, University of Sheffield, Sheffield, South Yorkshire, UK
| | - D Capener
- University of Sheffield, Cardiovascular Science Department, Sheffield, South Yorkshire, UK
| | - D G Kiely
- Pulmonary Vascular Disease Unit, Sheffield, South Yorkshire, UK
| | - A J Swift
- University of Sheffield, Cardiovascular Science Department, Sheffield, South Yorkshire, UK; INSIGNEO-Institute for in silico Medicine, University of Sheffield, Sheffield, South Yorkshire, UK
| | - D R Hose
- University of Sheffield, Cardiovascular Science Department, Sheffield, South Yorkshire, UK; INSIGNEO-Institute for in silico Medicine, University of Sheffield, Sheffield, South Yorkshire, UK
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18
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Balanuca B, Lungu A, Hanganu AM, Stan LR, Vasile E, Iovu H. Hybrid nanocomposites based on POSS and networks of methacrylated camelina oil and various PEG derivatives. EUR J LIPID SCI TECH 2014. [DOI: 10.1002/ejlt.201300370] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Brindusa Balanuca
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Bucharest Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Bucharest Romania
| | - Ana-Maria Hanganu
- Center of Organic Chemistry “Costin D. Nenitescu”; Romanian Academy; Bucharest Romania
| | - Liane Raluca Stan
- Department of Organic Chemistry; University Politehnica of Bucharest; Bucharest Romania
| | - Eugeniu Vasile
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Bucharest Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Department of Bioresources and Polymer Science; University Politehnica of Bucharest; Bucharest Romania
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Abstract
The aim of this research is to evaluate the effect of silica nanoparticles (SNs) modification on the physicochemical properties of some hybrid nanocomposites. SNs with high specific surface area were silanized by two complementary mechanisms using organosilanes with different functionalities, 3-methacryloxypropyltrimethoxysilane (MPS), octyltrimethoxysilane (OTMS) or a mixture of them in order to generate a different interphase between the filler and the polymeric matrix. The SN silanization efficiency was investigated using Fourier transform infrared spectra, x-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis (TGA). Several types of hybrid nanocomposites based on dimethacrylate monomer and SN were synthesized by bulk polymerization process. The influence of the silanized SN on the methacrylic groups reactivity was studied using differential scanning calorimetry, and the thermostability of the hybrid nanocomposites was revealed by TGA. Additionally, the dynamic thermomechanical properties of the hybrid nanocomposites were determined by Dynamic Mechanical Analysis (DMA).
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Affiliation(s)
- Nicoleta-Mihaela Florea
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Bucharest, Romania
| | - Adriana Lungu
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Bucharest, Romania
| | - Eugeniu Vasile
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Bucharest, Romania
| | - Horia Iovu
- Advanced Polymer Materials Group, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Bucharest, Romania
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Zaharia C, Tudora MR, Stancu IC, Galateanu B, Lungu A, Cincu C. Characterization and deposition behavior of silk hydrogels soaked in simulated body fluid. Materials Science and Engineering: C 2012. [DOI: 10.1016/j.msec.2012.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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22
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23
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Lungu A, Şulcă NM, Vasile E, Badea N, Pârvu C, Iovu H. The influence of POSS substituent on synthesis and properties of hybrid materials based on urethane dimethacrylate (UDMA) and various polyhedral oligomeric silsesquioxane (POSS). J Appl Polym Sci 2011. [DOI: 10.1002/app.33930] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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24
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Flocea P, Verestiuc L, Popa M, Sunel V, Lungu A. Crosslinked Networks Based on Polysaccharides and Collagen for Pilocarpine Sustained Release. Journal of Macromolecular Science, Part A 2010. [DOI: 10.1080/10601321003742196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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25
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Barbu E, Verestiuc L, Iancu M, Jatariu A, Lungu A, Tsibouklis J. Hybrid polymeric hydrogels for ocular drug delivery: nanoparticulate systems from copolymers of acrylic acid-functionalized chitosan and N-isopropylacrylamide or 2-hydroxyethyl methacrylate. Nanotechnology 2009; 20:225108. [PMID: 19433871 DOI: 10.1088/0957-4484/20/22/225108] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nanoparticulate hybrid polymeric hydrogels (10-70 nm) have been obtained via the radical-induced co-polymerization of acrylic acid-functionalized chitosan with either N-isopropylacrylamide or 2-hydroxyethyl methacrylate, and the materials have been investigated for their ability to act as controlled release vehicles in ophthalmic drug delivery. Studies on the effects of network structure upon swelling properties, adhesiveness to substrates that mimic mucosal surfaces and biodegradability, coupled with in vitro drug release investigations employing ophthalmic drugs with differing aqueous solubilities, have identified nanoparticle compositions for each of the candidate drug molecules. The hybrid nanoparticles combine the temperature sensitivity of N-isopropylacrylamide or the good swelling characteristics of 2-hydroxyethyl methacrylate with the susceptibility of chitosan to lysozyme-induced biodegradation.
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Affiliation(s)
- Eugen Barbu
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth PO12DT, UK. eugen@
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26
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Lungu A, Zecheru T, Comsa S, Iovu H. Influence of Different Initiators Against the Mechanical Properties of Poly(e-caprolactone) used for Biodegradable Bone Implants. Rev Chim 2008. [DOI: 10.37358/rc.08.11.1997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability of a strict control for the advanced macromolecular structures synthesis has been an important objective in our research. The development of polymers with defined structures and properties, aimed at biomedical applications, leads to complex and advanced architecture and diversity of the biodegradable polymers. Ring-opening polymerization is one of the most common methods for the synthesis of polymers with improved characteristics. Poly e-(caprolactone) (PCL) is prepared by ring-opening polymerization of the monomer e-caprolactone. The main factors which influence the ring-opening polymerization are the reaction conditions, such as the nature of the initiator, type and concentration of catalyst, reaction temperature and time. Stannous (II) 2-ethylhexanoate is used to catalyze the polymerization and alcohols are used as initiators. The initiators are also used to control the polymers molecular weight. Despite the long use of this catalyst in both industrial use and polymer research, several questions about the properties of the final product still remain. Our study describes the polymerization of e-caprolactone performed in the presence of catalyst (stannous (II) 2-ethylhexanoate) and initiator (1, 6 hexandiol or trimethylol propane) at moderate temperature (110�C). The polymerization of e-caprolactone was also performed in the presence of catalyst alone in order to evaluate the effect of the initiator against the polymers molecular weight. The obtained polymers were characterized by FTIR, GPC and TGA with respect to their mechanical properties. It is crucial to control the molecular weight of PCL for biomedical and pharmaceutical applications, because its molecular weight determines the hydrolysis rate. Several ratios among monomer, catalyst and initiator were studied, and we chose an optimum composition, in order to control the mechanical properties, degradation profiles respectively, and to avoid the cytotoxicity given by the reagents used.
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27
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Datta T, Yin M, Dimofte A, Bleiweiss M, Lungu A, Amirzadeh J, Sharp WE. Tidal effects on gravity experiments with a balance. Phys Rev Lett 2003; 91:109001-109002. [PMID: 14525518 DOI: 10.1103/physrevlett.91.109001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2002] [Indexed: 05/24/2023]
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28
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Lungu A, Neckers DC. Cross-Polarization Magic-Angle Spinning 13C Nuclear Magnetic Resonance Study of the Homogeneity of Some Photopolymerized Acrylic Networks. Macromolecules 2002. [DOI: 10.1021/ma00128a026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Iqbal Z, Datta T, Kirven D, Lungu A, Barry JC, Owens FJ, Rinzler AG, Yang D, Reidinger F. Superconductivity above 130 K in the Hg-Pb-Ba-Ca-Cu-O system. Phys Rev B Condens Matter 1994; 49:12322-12325. [PMID: 10010120 DOI: 10.1103/physrevb.49.12322] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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30
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Lungu A, Militaru M. [Morphopathologic organ correlations in endogenous Cushing syndrome in the dog]. Rom J Morphol Embryol 1993; 39:157-62. [PMID: 7849285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- A Lungu
- Tierürzliche Fakultät, Lehrstuhl für Morphopathologie, Bukarest, Rumänien
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31
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Popovici V, Lungu A, Ungureanu A. Histopathology of the experimental tick-borne encephalitis in mice. Rom J Morphol Embryol 1993; 39:33-6. [PMID: 8032018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This paper is concerned with the histopathology of the tick-borne encephalitis virus experimental infection in mice. The lesions observed in the kidneys, spleen, myocardium and especially in the encephalon are characteristic of severe vasculitis which could be the first and probably the most important event in the virus-induced encephalitis.
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32
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Lungu A. [A comparison of the morphological aspects of the pregnant and non-pregnant sheep myometrium]. Rom J Morphol Embryol 1992; 38:7-11. [PMID: 1295611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- A Lungu
- Tierärztliche Fakultät, Bukarest Lehrstuhl für Normalen und Pathologischen Morphologie
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33
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Dănăilă L, Duţu DC, Lungu A, Stefănescu F, Bratu S, Dragomirescu E. [Neurosurgical operations performed with the CO2 laser]. Rev Med Interna Neurol Psihiatr Neurochir Dermatovenerol Neurol Psihiatr Neurochir 1987; 32:273-87. [PMID: 2964713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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34
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Dănăilă L, Olărescu A, Gheorghiţescu L, Lungu A, Bratu S. Carotid endarterectomy. Neurol Psychiatr (Bucur) 1985; 23:213-20. [PMID: 4081570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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35
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Dănăilă L, Olărescu A, Gheorghiţescu L, Lungu A, Bratu S. Extra-intracranial anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery. Neurol Psychiatr (Bucur) 1984; 22:251-61. [PMID: 6515298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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36
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Dănăilă L, Simionescu N, Olărescu A, Lungu A, Gheorghiţescu L, Bratu S. Conservative treatment of supratentorial intracerebral hematomas. Neurol Psychiatr (Bucur) 1984; 22:185-91. [PMID: 6494774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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37
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Luciu R, Patriche E, Săvescu A, Lungu A. [The role of auxilliary personnel in neonatal surgical emergencies]. Viata Med Rev Inf Prof Stiint Cadrelor Medii Sanit 1982; 30:97-9. [PMID: 6815883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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38
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Arseni C, Maretsis M, Lungu A. [Characteristics of exophthalmos in an orbital cystic dermoid tumor]. Rev Chir Oncol Radiol O R L Oftalmol Stomatol Ser Oftalmol 1981; 25:121-4. [PMID: 6457353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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39
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Lungu A. [Specific differentiation of stress reactions]. Stud Cercet Endocrinol 1967; 18:193-195. [PMID: 6043531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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40
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Lungu A, Tache A, Cocu F, Dinu I, Teodoru V. Environmental temperature and 17-ketosteroidogenesis in sheep. Int J Biometeorol 1966; 10:155-161. [PMID: 6009552 DOI: 10.1007/bf01426861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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41
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Lungu A, Bunea M, Jelea A, Tache A. [Participation of the adrenal cortex in the physiopathologic mechanism of bronchial asthma]. Med Interna (Bucur) 1966; 18:757-64. [PMID: 5965389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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42
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Lungu A, Jelea A, Tache A, Bunea M. [Correlation between atmospheric pressure and urinary 17-ketosterids in relation to the clinical evolution of bronchial asthma]. Stud Cercet Endocrinol 1966; 17:555-561. [PMID: 5966092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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