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Zhang Y, Chen Y, Liu Z, Peng X, Lu J, Wang K, Zhang L. Encapsulation of a novel peptide derived from histatin-1 in liposomes against initial enamel caries in vitro and in vivo. Clin Oral Investig 2023; 28:35. [PMID: 38147166 DOI: 10.1007/s00784-023-05465-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 12/18/2023] [Indexed: 12/27/2023]
Abstract
OBJECTIVES Biomimetic mineralization mediated by proteins and peptides is a promising strategy for enamel repair, and its specific application model needs more research. In this work, we exploited a liposomal delivery system for a novel peptide (DK5) derived from histatin-1 (DK5-Lips) as a new biomimetic mineralization strategy against initial enamel caries. MATERIALS AND METHODS The DK5-Lips was prepared using calcium acetate gradient method and then the in vitro release, salivary stability, and cytotoxicity were studied. Initial enamel caries was created in bovine enamel blocks and subjected to pH-cycling model treated with DK5-Lips. Surface microhardness testing, polarized light microscopy (PLM), and transverse microradiography (TMR) were analyzed. Then the biocompatibility of DK5-Lips was evaluated in the caries model of Sprague-Dawley rats, and the anti-caries effect was assessed using Micro-CT analysis, Keyes scores, and PLM in vivo. RESULTS DK5-Lips provided a mean particle size of (97.63 ± 4.94)nm and encapsulation efficiency of (61.46 ± 1.44)%, exhibiting a sustained release profile, excellent stability in saliva, and no significant toxicity on human gingival fibroblasts (HGFs). The DK5-Lips group had higher surface microhardness recovery, shallower caries depth, and less mineral loss in bovine enamel. Animal experiments showed higher volume and density values of residual molar enamel, lower Keyes score, and shallower lesion depth of the DK5-Lips group with good biocompatibility. CONCLUSION As a safe and effective application model, DK5-Lips could significantly promote the remineralization of initial enamel caries both in vitro and in vivo. CLINICAL RELEVANCE The potential of liposome utilization as vehicle for oral delivery of functional peptides may provide a new way for enamel restoration.
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Grants
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 81970931 the National Natural Science Foundation of China
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- 2022YFS0287 the Sichuan Provincial Department of Science and Technology Program
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
- grant RD-02-202010 the Research and Development Program, West China Hospital of Stomatology, Sichuan University
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Affiliation(s)
- Yinmo Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China
| | - Yue Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China
- Department of Stomatology, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Science, Beijing, China
| | - Zhenqi Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China
| | - Xiu Peng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China
| | - Junzhuo Lu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China
| | - Kun Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China.
| | - Linglin Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Section 3 of Renmin Road South, Chengdu, 610041, China.
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Precipitation of Calcium Phosphates and Calcium Carbonates in the Presence of Differently Charged Liposomes. MINERALS 2022. [DOI: 10.3390/min12020208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Liposomes (lipid vesicles) are often considered to be a versatile tool for the synthesis of advanced materials, as they allow various control mechanisms to tune the materials’ properties. Among diverse materials, the synthesis of calcium phosphates (CaPs) and calcium carbonates (CaCO3) using liposomes has attracted particular attention in the development of novel (bio)materials and biomineralization research. However, the preparation of materials using liposomes has not yet been fully exploited. Most of the liposomes used have been anionic and/or zwitterionic, while data on the influence of cationic liposomes are limited. Therefore, the aim of this study was to investigate and compare the influence of differently charged liposomes on CaPs and CaCO3 formation. Zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), negatively charged 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS), and positively charged 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC) lipids were used to prepare the respective liposomes. The presence of liposomes during the spontaneous precipitation of CaPs and CaCO3 affected both the precipitation and transformation kinetics, as well as the morphology of the precipitates formed. The most prominent effect was noted for both materials in the presence of DMPS liposomes, as (nano) shell structures were formed in both cases. The obtained results indicate possible strategies to fine-tune the precipitation process of CaPs and CaCO3, which may be of interest for the production of novel materials.
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Matrix Vesicles: Role in Bone Mineralization and Potential Use as Therapeutics. Pharmaceuticals (Basel) 2021; 14:ph14040289. [PMID: 33805145 PMCID: PMC8064082 DOI: 10.3390/ph14040289] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/14/2022] Open
Abstract
Bone is a complex organ maintained by three main cell types: osteoblasts, osteoclasts, and osteocytes. During bone formation, osteoblasts deposit a mineralized organic matrix. Evidence shows that bone cells release extracellular vesicles (EVs): nano-sized bilayer vesicles, which are involved in intercellular communication by delivering their cargoes through protein–ligand interactions or fusion to the plasma membrane of the recipient cell. Osteoblasts shed a subset of EVs known as matrix vesicles (MtVs), which contain phosphatases, calcium, and inorganic phosphate. These vesicles are believed to have a major role in matrix mineralization, and they feature bone-targeting and osteo-inductive properties. Understanding their contribution in bone formation and mineralization could help to target bone pathologies or bone regeneration using novel approaches such as stimulating MtV secretion in vivo, or the administration of in vitro or biomimetically produced MtVs. This review attempts to discuss the role of MtVs in biomineralization and their potential application for bone pathologies and bone regeneration.
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Bottini M, Mebarek S, Anderson KL, Strzelecka-Kiliszek A, Bozycki L, Simão AMS, Bolean M, Ciancaglini P, Pikula JB, Pikula S, Magne D, Volkmann N, Hanein D, Millán JL, Buchet R. Matrix vesicles from chondrocytes and osteoblasts: Their biogenesis, properties, functions and biomimetic models. Biochim Biophys Acta Gen Subj 2018; 1862:532-546. [PMID: 29108957 PMCID: PMC5801150 DOI: 10.1016/j.bbagen.2017.11.005] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/28/2017] [Accepted: 11/01/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Matrix vesicles (MVs) are released from hypertrophic chondrocytes and from mature osteoblasts, the cells responsible for endochondral and membranous ossification. Under pathological conditions, they can also be released from cells of non-skeletal tissues such as vascular smooth muscle cells. MVs are extracellular vesicles of approximately 100-300nm diameter harboring the biochemical machinery needed to induce mineralization. SCOPE OF THE REVIEW The review comprehensively delineates our current knowledge of MV biology and highlights open questions aiming to stimulate further research. The review is constructed as a series of questions addressing issues of MVs ranging from their biogenesis and functions, to biomimetic models. It critically evaluates experimental data including their isolation and characterization methods, like lipidomics, proteomics, transmission electron microscopy, atomic force microscopy and proteoliposome models mimicking MVs. MAJOR CONCLUSIONS MVs have a relatively well-defined function as initiators of mineralization. They bind to collagen and their composition reflects the composition of lipid rafts. We call attention to the as yet unclear mechanisms leading to the biogenesis of MVs, and how minerals form and when they are formed. We discuss the prospects of employing upcoming experimental models to deepen our understanding of MV-mediated mineralization and mineralization disorders such as the use of reconstituted lipid vesicles, proteoliposomes and, native sample preparations and high-resolution technologies. GENERAL SIGNIFICANCE MVs have been extensively investigated owing to their roles in skeletal and ectopic mineralization. MVs serve as a model system for lipid raft structures, and for the mechanisms of genesis and release of extracellular vesicles.
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Affiliation(s)
- Massimo Bottini
- University of Rome Tor Vergata, Department of Experimental Medicine and Surgery, 00133 Roma, Italy; Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Saida Mebarek
- Universite Lyon 1, UFR Chimie Biochimie, 69 622 Villeurbanne Cedex, France; ICBMS UMR 5246 CNRS, 69 622 Villeurbanne Cedex, France; INSA, Lyon, 69 622 Villeurbanne Cedex, France; CPE, Lyon, 69 622 Villeurbanne Cedex, France; Universite de Lyon, 69 622 Villeurbanne Cedex, France
| | - Karen L Anderson
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Agnieszka Strzelecka-Kiliszek
- Nencki Institute of Experimental Biology, Department of Biochemistry, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Lukasz Bozycki
- Nencki Institute of Experimental Biology, Department of Biochemistry, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Ana Maria Sper Simão
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Departamento de Química, 14040-901 Ribeirão Preto, SP, Brazil
| | - Maytê Bolean
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Departamento de Química, 14040-901 Ribeirão Preto, SP, Brazil
| | - Pietro Ciancaglini
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Departamento de Química, 14040-901 Ribeirão Preto, SP, Brazil
| | - Joanna Bandorowicz Pikula
- Nencki Institute of Experimental Biology, Department of Biochemistry, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Slawomir Pikula
- Nencki Institute of Experimental Biology, Department of Biochemistry, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - David Magne
- Universite Lyon 1, UFR Chimie Biochimie, 69 622 Villeurbanne Cedex, France; ICBMS UMR 5246 CNRS, 69 622 Villeurbanne Cedex, France; INSA, Lyon, 69 622 Villeurbanne Cedex, France; CPE, Lyon, 69 622 Villeurbanne Cedex, France; Universite de Lyon, 69 622 Villeurbanne Cedex, France
| | - Niels Volkmann
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Dorit Hanein
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - José Luis Millán
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Rene Buchet
- Universite Lyon 1, UFR Chimie Biochimie, 69 622 Villeurbanne Cedex, France; ICBMS UMR 5246 CNRS, 69 622 Villeurbanne Cedex, France; INSA, Lyon, 69 622 Villeurbanne Cedex, France; CPE, Lyon, 69 622 Villeurbanne Cedex, France; Universite de Lyon, 69 622 Villeurbanne Cedex, France.
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Bolean M, Simão AMS, Kiffer-Moreira T, Hoylaerts MF, Millán JL, Itri R, Ciancaglini P. Proteoliposomes with the ability to transport Ca(2+) into the vesicles and hydrolyze phosphosubstrates on their surface. Arch Biochem Biophys 2015; 584:79-89. [PMID: 26325078 DOI: 10.1016/j.abb.2015.08.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/26/2015] [Accepted: 08/27/2015] [Indexed: 11/19/2022]
Abstract
We describe the production of stable DPPC and DPPC:DPPS-proteoliposomes harboring annexin V (AnxA5) and tissue-nonspecific alkaline phosphatase (TNAP) and their use to investigate whether the presence of AnxA5 impacts the kinetic parameters for hydrolysis of TNAP substrates at physiological pH. The best catalytic efficiency was achieved in DPPS 10%-proteoliposomes (molar ratio), conditions that also increased the specificity of TNAP hydrolysis of PPi. Melting behavior of liposomes and proteoliposomes was analyzed via differential scanning calorimetry. The presence of 10% DPPS in DPPC-liposomes causes a broadening of the transition peaks, with AnxA5 and TNAP promoting a decrease in ΔH values. AnxA5 was able to mediate Ca(2+)-influx into the DPPC and DPPC:DPPS 10%-vesicles at physiological Ca(2+) concentrations (∼2 mM). This process was not affected by the presence of TNAP in the proteoliposomes. However, AnxA5 significantly affects the hydrolysis of TNAP substrates. Studies with GUVs confirmed the functional reconstitution of AnxA5 in the mimetic systems. These proteoliposomes are useful as mimetics of mineralizing cell-derived matrix vesicles, known to be responsible for the initiation of endochondral ossification, as they successfully transport Ca(2+) and possess the ability to hydrolyze phosphosubstrates in the lipid-water interface.
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Affiliation(s)
- Maytê Bolean
- Depto. Química, FFCLRP-USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Ana Maria S Simão
- Depto. Química, FFCLRP-USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Tina Kiffer-Moreira
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Marc F Hoylaerts
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Rosangela Itri
- Depto. Física Aplicada, Instituto de Física, IF-USP, São Paulo, SP, Brazil
| | - Pietro Ciancaglini
- Depto. Química, FFCLRP-USP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
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Ding GJ, Zhu YJ, Qi C, Lu BQ, Chen F, Wu J. Porous hollow microspheres of amorphous calcium phosphate: soybean lecithin templated microwave-assisted hydrothermal synthesis and application in drug delivery. J Mater Chem B 2015; 3:1823-1830. [PMID: 32262255 DOI: 10.1039/c4tb01862a] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Calcium phosphate biomaterials are very promising for various biomedical applications owing to their excellent biocompatibility and biodegradability. Calcium phosphate nanostructured materials with a porous and hollow structure are excellent drug carriers due to their advantages such as high biocompatibility, large specific surface area, nanosized channels for drug loading and release, high drug loading capacity and pH-responsive drug release behavior. In this work, porous hollow microspheres of amorphous calcium phosphate have been successfully prepared by the microwave-assisted hydrothermal method using adenosine triphosphate disodium salt, CaCl2 and soybean lecithin in aqueous solution. This preparation method is facile, rapid, energy-saving and environment friendly. The effects of microwave hydrothermal temperature and concentrations of the reactants on the morphology and structure of the product were investigated. The as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The as-prepared porous hollow microspheres of amorphous calcium phosphate are efficient for drug loading and release, and the drug delivery system shows a pH-responsive drug release behavior and high ability to damage tumor cells. Thus, the as-prepared porous hollow microspheres of amorphous calcium phosphate are promising for the applications in various biomedical fields.
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Affiliation(s)
- Guan-Jun Ding
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China.
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Ciancaglini P, Simão AMS, Bolean M, Millán JL, Rigos CF, Yoneda JS, Colhone MC, Stabeli RG. Proteoliposomes in nanobiotechnology. Biophys Rev 2012; 4:67-81. [PMID: 28510001 PMCID: PMC5418368 DOI: 10.1007/s12551-011-0065-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 12/22/2011] [Indexed: 01/08/2023] Open
Abstract
Proteoliposomes are systems that mimic lipid membranes (liposomes) to which a protein has been incorporated or inserted. During the last decade, these systems have gained prominence as tools for biophysical studies on lipid-protein interactions as well as for their biotechnological applications. Proteoliposomes have a major advantage when compared with natural membrane systems, since they can be obtained with a smaller number of lipidic (and protein) components, facilitating the design and interpretation of certain experiments. However, they have the disadvantage of requiring methodological standardization for incorporation of each specific protein, and the need to verify that the reconstitution procedure has yielded the correct orientation of the protein in the proteoliposome system with recovery of its functional activity. In this review, we chose two proteins under study in our laboratory to exemplify the steps necessary for the standardization of the reconstitution of membrane proteins in liposome systems: (1) alkaline phosphatase, a protein with a glycosylphosphatidylinositol anchor, and (2) Na,K-ATPase, an integral membrane protein. In these examples, we focus on the production of the specific proteoliposomes, as well as on their biochemical and biophysical characterization, with emphasis on studies of lipid-protein interactions. We conclude the chapter by highlighting current prospects of this technology for biotechnological applications, including the construction of nanosensors and of a multi-protein nanovesicular biomimetic to study the processes of initiation of skeletal mineralization.
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Affiliation(s)
- P Ciancaglini
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil.
| | - A M S Simão
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil
| | - M Bolean
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil
| | - J L Millán
- Sanford Children's Health Research Center, Sanford - Burnham Medical Research Institute, La Jolla, CA, USA
| | - C F Rigos
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil
| | - J S Yoneda
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil
| | - M C Colhone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da (FFCLRP), Universidade de São Paulo - USP, 14040-901, Ribeirão Preto, SP, Brazil
| | - R G Stabeli
- Centro de Estudos de Biomoléculas Aplicadas a Medicina, Núcleo de Saúde (NUSAU), Universidade Federal de Rondônia (UNIR), 76800-000, Porto Velho, RO, Brazil
- Fundação Oswaldo Cruz (Fiocruz-Rondonia), Ministério da Saúde, 76812-245, Porto Velho, RO, Brazil
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Simão AMS, Yadav MC, Ciancaglini P, Millán JL. Proteoliposomes as matrix vesicles' biomimetics to study the initiation of skeletal mineralization. Braz J Med Biol Res 2010; 43:234-41. [PMID: 20401430 DOI: 10.1590/s0100-879x2010007500008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Accepted: 02/05/2010] [Indexed: 11/21/2022] Open
Abstract
During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Ion transporters control the availability of phosphate and calcium needed for HA deposition. The lipidic microenvironment in which MV-associated enzymes and transporters function plays a crucial physiological role and must be taken into account when attempting to elucidate their interplay during the initiation of biomineralization. In this short mini-review, we discuss the potential use of proteoliposome systems as chondrocyte- and osteoblast-derived MVs biomimetics, as a means of reconstituting a phospholipid microenvironment in a manner that recapitulates the native functional MV microenvironment. Such a system can be used to elucidate the interplay of MV enzymes during catalysis of biomineralization substrates and in modulating in vitro calcification. As such, the enzymatic defects associated with disease-causing mutations in MV enzymes could be studied in an artificial vesicular environment that better mimics their in vivo biological milieu. These artificial systems could also be used for the screening of small molecule compounds able to modulate the activity of MV enzymes for potential therapeutic uses. Such a nanovesicular system could also prove useful for the repair/treatment of craniofacial and other skeletal defects and to facilitate the mineralization of titanium-based tooth implants.
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Affiliation(s)
- A M S Simão
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
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Simão AMS, Yadav MC, Narisawa S, Bolean M, Pizauro JM, Hoylaerts MF, Ciancaglini P, Millán JL. Proteoliposomes harboring alkaline phosphatase and nucleotide pyrophosphatase as matrix vesicle biomimetics. J Biol Chem 2010; 285:7598-609. [PMID: 20048161 PMCID: PMC2844207 DOI: 10.1074/jbc.m109.079830] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 12/15/2009] [Indexed: 01/01/2023] Open
Abstract
We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in pure dipalmitoyl phosphatidylcholine (DPPC), DPPC/dipalmitoyl phosphatidylserine (9:1 and 8:2), and DPPC/dioctadecyl-dimethylammonium bromide (9:1 and 8:2) mixtures. TNAP reconstitution proved virtually complete in DPPC liposomes. Next, proteoliposomes containing either recombinant TNAP, recombinant NPP1, or both together were reconstituted in DPPC, and the hydrolysis of ATP, ADP, AMP, pyridoxal-5'-phosphate (PLP), p-nitrophenyl phosphate, p-nitrophenylthymidine 5'-monophosphate, and PP(i) by these proteoliposomes was studied at physiological pH. p-Nitrophenylthymidine 5'-monophosphate and PLP were exclusively hydrolyzed by NPP1-containing and TNAP-containing proteoliposomes, respectively. In contrast, ATP, ADP, AMP, PLP, p-nitrophenyl phosphate, and PP(i) were hydrolyzed by TNAP-, NPP1-, and TNAP plus NPP1-containing proteoliposomes. NPP1 plus TNAP additively hydrolyzed ATP, but TNAP appeared more active in AMP formation than NPP1. Hydrolysis of PP(i) by TNAP-, and TNAP plus NPP1-containing proteoliposomes occurred with catalytic efficiencies and mild cooperativity, effects comparable with those manifested by murine osteoblast-derived MVs. The reconstitution of TNAP and NPP1 into proteoliposome membranes generates a phospholipid microenvironment that allows the kinetic study of phosphosubstrate catabolism in a manner that recapitulates the native MV microenvironment.
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Affiliation(s)
- Ana Maria S. Simão
- From the Department of Chemistry, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto SP 14040-901, Brazil
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
| | - Manisha C. Yadav
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
| | - Sonoko Narisawa
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
| | - Mayte Bolean
- From the Department of Chemistry, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto SP 14040-901, Brazil
| | - Joao Martins Pizauro
- the Department of Technology, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, Universidade Estadual Paulista, Jaboticabal SP 14884-900, Brazil, and
| | - Marc F. Hoylaerts
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
- the Center for Molecular and Vascular Biology, University of Leuven, B-3000, Leuven, Belgium
| | - Pietro Ciancaglini
- From the Department of Chemistry, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto SP 14040-901, Brazil
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
| | - José Luis Millán
- the Sanford Children's Health Research Center, Burnham Institute for Medical Research, La Jolla, California 92037
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Literature Alerts. J Microencapsul 2008. [DOI: 10.3109/02652048609049586] [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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Merolli A, Bosetti M, Giannotta L, Lloyd AW, Denyer SP, Rhys-Williams W, Love WG, Gabbi C, Cacchioli A, Leali PT, Cannas M, Santin M. In vivo assessment of the osteointegrative potential of phosphatidylserine-based coatings. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2006; 17:789-94. [PMID: 16932859 DOI: 10.1007/s10856-006-9836-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Accepted: 10/21/2005] [Indexed: 05/11/2023]
Abstract
The successful implantation of titanium-based implants for orthopaedic and dental applications is often hindered because of their mobility, which arises because of a lack of direct binding of the metal surface to the mineral phase of the surrounding bone. Ceramic coatings, although ensuring the integration of the implant within the tissue, are unstable and carry risks of delamination and of failure. Recently, a novel biomimetic approach has been developed where porous titanium implants are coated with calcium-binding phospholipids able to catalyse the nucleation of discrete apatite crystals after only 30 min incubation in simulated body fluids. The present work assesses the osteointegrative potential of this new class of coatings in an in vivo rabbit model and compares its performance with those of bare porous titanium and hydroxyapatite-coated titanium. The data obtained show that phosphatidylserine-based coatings, whilst resorbing, drive the growing bone into apposition with the metal surface. This is in contrast to the case of bare titanium.
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Affiliation(s)
- A Merolli
- Universita' Cattolica, Clinica Ortopedica, Rome, Italy.
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12
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Santin M, Rhys-Williams W, O'Reilly J, Davies MC, Shakesheff K, Love WG, Lloyd AW, Denyer SP. Calcium-binding phospholipids as a coating material for implant osteointegration. J R Soc Interface 2006; 3:277-81. [PMID: 16849237 PMCID: PMC1578739 DOI: 10.1098/rsif.2005.0088] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Among the many biomolecules involved in the bone mineralization processes, anionic phospholipids play an important role because of their ability to bind calcium. In particular, phosphatidylserine is a natural component of the plasmalemma and of the matrix vesicles generated from the osteoblast membrane to create nucleation centres for calcium phosphate crystal precipitation. In the present work, we demonstrate that calcium-binding phospholipids can be used as biomimetic coating materials for improving the osteointegration of metal implants. Relatively thick phosphatidylserine-based coatings were deposited on titanium coupons by dip-coating. Upon dehydration in a simulated body fluid phospholipids were quickly crosslinked by calcium and re-arranged into a three-dimensional matrix able to induce rapid formation of a calcium phosphate mineral phase. The rate of mineralization was shown to be dependent on the adopted coating formulation. In the attempt to closely mimic the cell membrane composition, heterogeneous formulations based on the mixing of anionic phospholipids (either phosphatidylserine or phosphatidylinositol) with phosphatidylcholine and cholesterol were synthesized. However, surface plasmon resonance studies as well as scanning electron microscopy and elemental analysis demonstrated that the homogeneous phosphatidylserine coating was a more effective calcification environment than the heterogeneous formulations.
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Affiliation(s)
- Matteo Santin
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ, UK.
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13
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Garimella R, Bi X, Anderson HC, Camacho NP. Nature of phosphate substrate as a major determinant of mineral type formed in matrix vesicle-mediated in vitro mineralization: An FTIR imaging study. Bone 2006; 38:811-7. [PMID: 16461032 DOI: 10.1016/j.bone.2005.11.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Revised: 11/09/2005] [Accepted: 11/14/2005] [Indexed: 10/25/2022]
Abstract
Membrane-bound extracellular matrix vesicles play an important role in the de novo initiation and propagation of calcium-phosphate mineral formation in calcifying cartilage, bone, dentin, and in pathologic calcification. Characterization of the phase, composition, crystal size, and perfection provides valuable insight into the mechanism of the mineral deposition. In the present study, Fourier transform infrared imaging spectroscopy (FT-IRIS) was used to characterize the mineral phase generated during MV-mediated in vitro mineralization. FT-IRIS studies revealed that the mineral phase associated with MVs calcified in the presence of AMP and beta-GP was always found to be crystalline hydroxyapatite while with ATP only a small amount of immature mineral, most likely an amorphous or poorly crystalline hydroxyapatite, was observed. Low concentrations of pyrophosphate (PPi) (< or = 0.01 mM) showed apatitic mineral while high concentrations showed immature calcium pyrophosphate dihydrate (CPPD). The implications of these findings are that (a) hydrolysis of AMP or beta-GP, monophosphoester substrates of MV-5' AMPase (substrate: AMP) and TNAP (substrates: AMP, beta-GP), yields orthophosphate (Pi) which leads to the formation of mature crystalline, apatite mineral, while the hydrolysis of ATP, substrate for MV-TNAP or ATPase or NPP1, inhibits the formation of mature hydroxyapatite, and (b) pyrophosphate (PPi) has a bimodal effect on mineralization, i.e., at low PPi concentrations, alkaline phosphatase activity of matrix vesicles is able to hydrolyze PPi to orthophosphate and thus facilitates the formation of basic calcium phosphate mineral which subsequently transforms into apatitic mineral. We hypothesize that, at high PPi concentrations, PPi by itself or Pi released by partial PPi hydrolysis could act as inhibitors of alkaline phosphatase activity, thereby preventing complete hydrolysis of PPi to Pi, and thus resulting in the accumulation of calcium pyrophosphate dihydrate. Therefore, in order for physiological mineralization to proceed, a balance is required between levels of Pi and PPi.
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Affiliation(s)
- Rama Garimella
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, 66160, USA
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14
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Talham DR, Backov R, Benitez IO, Sharbaugh DM, Whipps S, Khan SR. Role of lipids in urinary stones: studies of calcium oxalate precipitation at phospholipid langmuir monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:2450-6. [PMID: 16519440 DOI: 10.1021/la052503u] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This article reviews the authors' experiments on calcium oxalate growth at lipid monolayers. Calcium oxalate is the principal mineral component of most urinary stones. Membrane constituents associate either actively or passively with calcific minerals during stone formation, and it has been proposed that lipid assemblies play a significant role, possibly providing sites for the initial nucleation event. Langmuir monolayers allow systematic studies of the heterogeneous precipitation of calcium oxalate at lipid assemblies. The influences of the chemical identity of the lipid headgroup, the organization of the monolayer, and the presence of heterogeneities and phase boundaries within the monolayer have been explored.
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Affiliation(s)
- Daniel R Talham
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
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15
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Camolezi FL, Daghastanli KRP, Magalhães PP, Pizauro JM, Ciancaglini P. Construction of an alkaline phosphatase-liposome system: a tool for biomineralization study. Int J Biochem Cell Biol 2002; 34:1091-101. [PMID: 12009304 DOI: 10.1016/s1357-2725(02)00029-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Alkaline phosphatase is required for the mineralization of bone and cartilage. This enzyme is localized in the matrix vesicle, which plays a role key in calcifying cartilage. In this paper, we standardize a method for construction an alkaline phosphatase liposome system to mimic matrix vesicles and examine a some kinetic behavior of the incorporated enzyme. Polidocanol-solubilized alkaline phosphatase, free of detergent, was incorporated into liposomes constituted from dimyristoylphosphatidylcholine (DMPC), dilaurilphosphatidylcholine (DLPC) or dipalmitoylphosphatidylcholine (DPPC). This process was time-dependent and >95% of the enzyme was incorporated into the liposome after 4h of incubation at 25 degrees C. Although, incorporation was more rapid when vesicles constituted from DPPC were used, the incorporation was more efficient using vesicles constituted from DMPC. The 395nm diameter of the alkaline phosphatase-liposome system was relatively homogeneous and more stable when stored at 4 degrees C. Alkaline phosphatase was completely released from liposome system only using purified phosphatidylinositol-specific phospholipase C (PIPLC). These experiments confirm that the interaction between alkaline phosphatase and lipid bilayer of liposome is via GPI anchor of the enzyme, alone. An important point shown is that an enzyme bound to liposome does not lose the ability to hydrolyze ATP, pyrophosphate and p-nitrophenyl phosphate (PNPP), but a liposome environment affects its kinetic properties, specifically for pyrophosphate. The standardization of such system allows the study of the effect of phospholipids and the enzyme in in vitro and in vivo mineralization, since it reproduces many essential features of the matrix vesicle.
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Affiliation(s)
- Fernando L Camolezi
- Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto-FFCLRP-USP, SP, Brazil
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16
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Stubbs JT. Generation and use of recombinant human bone sialoprotein and osteopontin for hydroxyapatite studies. Connect Tissue Res 2001; 35:393-9. [PMID: 9084680 DOI: 10.3109/03008209609029217] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bone sialoprotein (BSP) and osteopontin (OPN) are two extracellular bone matrix proteins that have the ability to modulate the growth of hydroxyapatite in vitro. Studies of BSP/OPN hydroxyapatite interactions in the past have been directed toward the identification of essential structural elements that allow these two proteins to modulate hydroxyapatite growth. However, these studies are limited by the finite quantities of purified extracellular matrix proteins. I have utilized a recombinant E. coli expression system to obtain milligram quantities of human bone sialoprotein and human osteopontin that may be used to study extracellular matrix protein interactions with hydroxyapatite.
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Affiliation(s)
- J T Stubbs
- Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892, USA
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17
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Murphy WL, Messersmith PB. Compartmental control of mineral formation: adaptation of a biomineralization strategy for biomedical use. Polyhedron 2000. [DOI: 10.1016/s0277-5387(99)00366-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Couchourel D, Escoffier C, Rohanizadeh R, Bohic S, Daculsi G, Fortun Y, Padrines M. Effects of fibronectin on hydroxyapatite formation. J Inorg Biochem 1999; 73:129-36. [PMID: 10331242 DOI: 10.1016/s0162-0134(99)00006-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
There is increasing evidence that noncollagenous matrix proteins initiate bone mineralization in vivo. Fibronectin, which is present during the early phases of mineralization, may contribute to this process in bone tissues. In this context, the mineralization potential of fibronectin was tested in an agarose gel precipitation system and a metastable calcium phosphate solution. The protein inhibited the precipitation of calcium phosphate crystals in solution but had no apparent effect in gel. Conversely, fibronectin stimulated crystal formation when apatite powder was used to seed crystal growth in gel. Although these results in vitro do not clearly indicate that fibronectin is involved in the mineralization process, they are consistent with in vivo events. Free fibronectin (e.g. in biological fluids) could inhibit crystal growth but might also activate the mineralization process when absorbed on apatite powder in a bone environment and areas of ectopic mineralization.
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Affiliation(s)
- D Couchourel
- Laboratoire de Recherche sur les Matériaux d'Intérêt Biologique, UPRES EA 2159, Faculté de Chirurgie Dentaire, Nantes, France
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19
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Goldberg M, Boskey AL. Lipids and biomineralizations. PROGRESS IN HISTOCHEMISTRY AND CYTOCHEMISTRY 1996; 31:1-187. [PMID: 8893307 DOI: 10.1016/s0079-6336(96)80011-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- M Goldberg
- Laboratoire de Biologie et Biomatériaux du Milieu Buccal et Osseux, Faculté de Chirurgie Dentaire, Université René Descartes Paris V 1, Montrouge, France
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20
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Skrtic D, Eanes ED. Effect of 1-hydroxyethylidene-1,1-bisphosphonate on membrane-mediated calcium phosphate formation in model liposomal suspensions. BONE AND MINERAL 1994; 26:219-29. [PMID: 7819829 DOI: 10.1016/s0169-6009(08)80171-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The bisphosphonate, 1-hydroxyethylidene-1,1-bisphosphonate (HEBP), was examined for its effect on calcium phosphate precipitation in pH 7.4, 22 degrees C suspensions of 7:2:1 PC:phosphatidylcholine (PC):dicetylphosphate (DCP):cholesterol (Chol) and 7:1:1 PC:phosphatidylserine (PS):Chol liposomes. HEBP (0.5-50 mumol/l) in the suspending medium had little, if any, effect on precipitation that formed inside phosphate-rich (50 mmol/l) aqueous interiors of liposomes as a result of ionophore (X-537A) driven 2.25 mmol/l Ca2+ influxes from the medium. On the other hand, HEBP had a significant negative impact on the subsequent spread of the precipitate into the surrounding medium when the latter was made metastable with 1.5 mmol/l total inorganic phosphate (PO4). The inhibitory effect of HEBP was more strongly felt in the 7PC:1PS:1Chol liposomal suspensions, with only 1 mumol/l HEBP needed to effectively block extraliposomal precipitation compared to 7.5 mumol/l for 7PC:2DCP:1Chol suspensions. Direct encapsulation of HEBP (1-1000 mumol/l) together with PO4 in the aqueous cores of 7PC:2DCP:1Chol liposomes reduced somewhat (approximately 30%) intraliposomal yields and delayed but did not block extraliposomal precipitate development. These results provide a possible physicochemical explanation for the suppression of matrix vesicle initiated mineralization in ectopically-induced osteoid tissue of HEBP treated mice [1]. In particular, the liposome results suggest that membrane phosphatidylserine interactions with mineral may enhance HEBP's effectiveness in vivo.
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Affiliation(s)
- D Skrtic
- National Institute of Dental Research's Research Associate Program, National Institute of Standards and Technology, Gaithersburg, MD 20899
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21
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Eanes ED, Hailer AW. Effect of ultrafilterable fragments from chondroitinase and protease-treated aggrecan on calcium phosphate precipitation in liposomal suspensions. Calcif Tissue Int 1994; 55:176-9. [PMID: 7987730 DOI: 10.1007/bf00425872] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A liposome-centered endogenous precipitation method was used to investigate the effect of ultrafilterable fragments from the enzymatic digestion of rat chondrosarcoma aggrecan on the formation of insoluble calcium phosphate salts in buffered solutions at pH 7.4 and 22 degrees C. Unlike the intact aggrecan and its major chondroitin sulfate and core protein components, disaccharide units from chondroitinase degradation of the aggrecan and small (< 3 kg/mol molecular weight) fragments from protease digestion of the core structure were found to be only weakly inhibitory toward mineral formation. Corresponding reductions in Ca(2+)-binding indicate that these fragments were unable to absorb to active sites on the apatite surface for long enough periods to significantly hinder crystal growth. The data suggest that controlled enzymatic breakdown of aggrecan may be one possible mechanism by which the calcification of growth plate cartilage is allowed to advance in vivo.
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Affiliation(s)
- E D Eanes
- National Institute of Dental Research's Bone Research Branch Research Associate Program, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
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22
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Abstract
Synthetic lipid vesicle (liposome) suspensions have been used to experimentally model many of the calcium phosphate precipitation steps observed in matrix vesicle (MV) calcification. In particular, precipitate development in liposomes can be made to preferentially follow the progression seen in MV, i.e. to occur initially in intraliposomal spaces and then to expand into the surrounding suspending medium. This paper reviews results from studies by us which show that certain phospholipid (PL) constituents of the liposomal membrane can modulate this progression. Of greatest relevance to MV calcification is the observation that phosphatidylserine and sphingomyelin, two lipids selectively enriched in MV, slow the expansion of the precipitation from inside to outside the liposome.
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Affiliation(s)
- E D Eanes
- Bone Research Branch Research Associate Program, National Institute of Dental Research, Gaithersburg, Maryland 20899
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23
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Skrtic D, Eanes ED. Effect of different phospholipid-cholesterol membrane compositions on liposome-mediated formation of calcium phosphates. Calcif Tissue Int 1992; 50:253-60. [PMID: 1617500 DOI: 10.1007/bf00296290] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present report compares the effects of different membrane phospholipid (PL)-cholesterol compositions on the kinetics of liposome-mediated formation of calcium phosphates from metastable solutions (2.25 mM CaCl2; 1.5 mM KH2PO4) at 22 degrees C, pH 7.4 and 240 mOsm. In most experiments, the liposomes were composed of 7:2:X mixtures of phosphatidylcholine (PC), neutral or acidic phospholipids, and cholesterol (Chol, X = 0, 10, 35, or 50 mol%). The neutral phospholipids (NPL) examined, in addition to PC, were phosphatidylethanolamine (PE) and sphingomyelin (Sph), and the acidic phospholipids (APL) examined were dicetylphosphate (DCP), dioleolylphosphatidylglycerol (DOPG), dioleolylphosphatidic acid (DOPA), phosphatidylserine (PS) and phosphatidylinositol (PI). The 7:2:X liposomes did not initiate mineralization in metasable external solutions per se or, with the exception of DOPA, show extensive Ca-PL binding. However, solution Ca2+ losses due to precipitation occurred when the liposomes were encapsulated with 50 mM KH2PO4 and made permeable to external Ca2+ with X-537A. The extent of these Ca2+ losses was sensitive to both the phospholipid and Chol makeup of the membrane. Moderate-to-extensive intraliposomal precipitation occurred in all 7PC:2APL and 7PC:2NPL liposomes containing 0 or 10 mol% Chol. In contrast, at 50 mol% Chol, mineralization inside all liposomes was negligible. The only significant discriminating effect on internal mineralization among the different phospholipids was observed at 35 mol% Chol, where mineral accumulations ranged from negligible to moderate. At 0 or 10 mol% Chol, extraliposomal precipitation was extensive in all but DOPA- and PS-containing liposomes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D Skrtic
- Bone Research Branch Research Associate Program, National Institute of Dental Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
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24
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Skrtic D, Eanes ED. Membrane-mediated precipitation of calcium phosphate in model liposomes with matrix vesicle-like lipid composition. BONE AND MINERAL 1992; 16:109-19. [PMID: 1576486 DOI: 10.1016/0169-6009(92)90881-d] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study examined calcium phosphate precipitation in aqueous suspensions of artificial liposomes which closely resembled matrix vesicles (MV) in membrane lipid composition. At 22 degrees C, the liposomes per se did not initiate precipitation in the suspending medium for up to 120 h when the latter was made supersaturated with respect to hydroxyapatite (2.25 mM Ca2+, 1.5 mM PO4, 240 mosmol, pH 7.4). Likewise, the suspending medium remained stable for up to 72 h when precipitation was induced within the aqueous interiors of the liposomes by encapsulating pH 7.4-buffered 50 mM PO4 solutions in the interior spaces and making the enclosing membranes permeable to external solution Ca2+ ions with the ionophore X-537A. However, extraliposomal precipitation readily occurred under these latter conditions when phosphatidylserine (PS) and sphingomyelin (Sph) were deleted from the MV-like lipid formulation used to prepare the liposomes. These results suggest that lipidic membrane constituents such as PS and Sph may have a controlling influence on MV-mediated calcification in vivo by affecting the release of intravesicularly formed mineral crystals into the extracellular matrix space where they can subsequently grow and proliferate.
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Affiliation(s)
- D Skrtic
- Bone Research Branch Research Associate Program, National Institute of Dental Research, National Institute of Standards and Technology, Gaithersburg, Maryland
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25
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Heywood BR, Eanes ED. An ultrastructural study of the effects of acidic phospholipid substitutions on calcium phosphate precipitation in anionic liposomes. Calcif Tissue Int 1992; 50:149-56. [PMID: 1315188 DOI: 10.1007/bf00298793] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A model membrane system was used to investigate the ability of specific membrane constituents to modulate the precipitation of calcium phosphate. Intraliposomal precipitation was induced in phosphate-encapsulated liposomes composed of 7:2:1 molar mixtures of phosphatidylcholine (PC), dicetyl phosphate (DCP), and cholesterol (Chol) by ionophore-supported (X-537A) Ca2+ uptake. Extraliposomal precipitation occurred when these reactions were initiated in metastable external solutions. In this case, the endogenously formed crystals penetrated through the enclosing lipid bilayers and seeded the external solution phase. Transmission electron microscopy (TEM) was used to monitor the effect of acidic phospholipids [phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylglycerol (PG)] on the precipitation reactions when these molecular species were incorporated into the liposome membranes. Compared with the precipitation reactions in 7PC:2DCP:1Chol liposomes containing no acidic phospholipids, calcium phosphate formation in the presence of monoester phosphate (PA) and amino- (PS) phospholipids was inhibited. Analyses of the lipid-mineral interactions in PA-containing (10 mol%) liposomes revealed close physical contact between the small crystals of apatite and the inner lipid bilayers; there was only minimal extraliposomal precipitation. A few small crystals adhered to the external surfaces of the liposomes. In PS-containing liposomes, lipid-mineral interactions were dependent upon the DCP content of the lipid membrane. Discrete clusters of crystals formed within the interior aqueous compartment when intraliposomal precipitation was initiated in 7PC:2DCP:1Chol liposomes doped with up to 10 mol% PS. There was no evidence for specific associations between these crystals and the enclosing lipid bilayers.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B R Heywood
- Bio-inorganic Chemistry Laboratory, School of Chemistry, University of Bath, Claverton Down, UK
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26
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Skrtic D, Eanes ED. Effect of membrane cholesterol on calcium phosphate formation in aqueous suspensions of anionic liposomes. Calcif Tissue Int 1992; 50:55-60. [PMID: 1739872 DOI: 10.1007/bf00297298] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The present study examined the effect of membrane cholesterol on liposome-mediated calcium phosphate precipitation in metastable aqueous solutions (2.25 mM Ca2+ and 1.5 mM inorganic phosphate) at 22 degrees C, pH 7.4 and 240 mOsm. The liposomes were prepared from 7:2:X molar mixtures of phosphatidylcholine, dicetylphosphate, and cholesterol (x = 0, 1, 5, or 9) and contained either 0 or 50 mM encapsulated phosphate. The membranes were made permeable to Ca2+ by addition of the cationophore, X-537A. Changes in external Ca2+ concentration were used as the principal monitor of the course of precipitation. Without encapsulated phosphate, 7:2:X liposomes (with or without ionophore) induced no precipitation. With 50 mM encapsulated phosphate and in the presence of ionophore, precipitation significantly depended on the cholesterol level in the membrane. At 0 and 10 mole% cholesterol, precipitate developed rapidly both within and outside the liposomes. At 35 and 50 mole% cholesterol, no observable intraliposomal precipitation occurred, and extraliposomal precipitation started only after an induction period of 24 hours. Delayed extraliposomal precipitation also took place in PO4-containing liposomes without added ionophore. In this latter case, however, cholesterol was essential for this precipitation to occur with the optimum level being around 10 mole%. Suppression of ionophore-mediated intraliposomal precipitation at higher cholesterol levels could be related to the inflexible cholesterol molecules making the membrane more rigid, thereby restricting Ca-ionophore transport. This restriction could be reversed with ethanol. Delayed extraliposomal precipitation in the absence of added ionophore (or at higher cholesterol levels in its presence) could be explained by seeding from low, unobserved levels of intraliposomal precipitate formed during slow, unfacilitated Ca2+ leakage into the liposomal interior.
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Affiliation(s)
- D Skrtic
- Bone Research Branch Research Associate Program, Natioanl Institute of Dental Research, Natioanl Institute of Standards and Technology, Gaithersburg, Maryland 20899
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27
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Boskey AL. The role of extracellular matrix components in dentin mineralization. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1991; 2:369-87. [PMID: 1654141 DOI: 10.1177/10454411910020030501] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The extracellular matrix of dentin consists of mineral (hydroxyapatite), collagen, and several noncollagenous matrix proteins. These noncollagenous matrix proteins may be mediators of cell-matrix interactions, matrix maturation, and mineralization. This review describes the current knowledge of the chemistry of mineral crystal formation in dentin with special emphasis on the roles of the dentin matrix proteins. The functions of some of these matrix proteins in the mineralization process have been deduced based on in vitro studies. Functions for others have been postulated based on analogy with some of the bone matrix proteins. Evidence suggests that several of these matrix proteins may have multiple effects on nucleation, crystal growth, and orientation of dentin hydroxyapatite.
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Affiliation(s)
- A L Boskey
- Laboratory for Ultrastructural Biochemistry, Hospital for Special Surgery, New York, New York
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28
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Eanes ED. Biophysical aspects of lipid interaction with mineral: liposome model studies. Anat Rec (Hoboken) 1989; 224:220-5. [PMID: 2672886 DOI: 10.1002/ar.1092240211] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The present paper reviews the use of liposomes as synthetic models for studying various biophysical aspects of matrix vesicle calcification, especially the involvement of acidic phospholipids in the nucleation and growth processes which occur during the initial stages of mineral formation in and around these membrane-bound structures. Recent results showed that acidic phospholipids incorporated into phosphatidylcholine-rich anionic liposome membranes were ineffective in initiating extraliposomal calcium phosphate precipitation from metastable solutions at physiological pH. On the contrary, certain acidic phospholipids such as phosphatidic acid and phosphatidylserine retarded the development of such precipitation when the latter was endogenously induced. The extent of inhibition correlated with the strength of the electrostatic interaction between the polar head group of the acidic phospholipid and the surface of the mineral phase. The results suggest that acidic phospholipids may play an important role in controlling the rate of early mineral development in matrix vesicle calcification.
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Affiliation(s)
- E D Eanes
- Bone Research Branch Research Associate Program, National Institute of Dental Research, National Bureau of Standards, Gaithersburg, Maryland 20899
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29
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Eanes ED, Hailer AW, Heywood BR. Modulation of calcium phosphate formation by phosphatidate-containing anionic liposomes. Calcif Tissue Int 1988; 43:226-34. [PMID: 3145128 DOI: 10.1007/bf02555139] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Liposome prepared from 7:2:1 molar mixtures of phosphatidylcholine, dicetyl phosphate, and cholesterol to which 1-20 mole % dioleoylphosphatidic acid (DOPA) was added were used to examine the effect of membrane-bound monoester phosphatidate anions on calcium phosphate formation in aqueous solutions at 22 degrees C, pH 7.4 and 240 mOsm. Results showed that up to 20 mole % DOPA in the liposomal envelope did not initiate mineralization in solutions made metastable with 2.25 mM CaCl2 and 1.50 mM KH2PO4. Results alos revealed that precipitation induced in metastable solutions by the seeding action of intraliposomally formed mineral was measurably reduced with as little as 1 mole % DOPA and completely suppressed with 5 mole % DOPA. In contrast, 10 mole % concentrations of diester phosphate lipids either had no effect on extraliposomal precipitation (e.g., phosphatidylglycerol and phosphatidylinositol) or, as reported previously for phosphatidylserine) only partially reduced the amount of precipitate formed. Transmission electron microscopical analysis suggests that DOPA-containing lipid bilayers adhering to the seed crystals inhibited extraliposomal mineralization by encapsulating the crystals within the liposomes and/or by blocking potential growth sites on the crystal faces. The polar head group of DOPA, being more negatively charged and sterically less encumbered than diester phosphate ligands, most probably was responsible for this adherence of the lipid bilayers to the crystal surfaces.
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Affiliation(s)
- E D Eanes
- National Institute of Dental Research, Bethesda, MD 20892
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Heywood BR, Eanes ED. An ultrastructural study of calcium phosphate formation in multilamellar liposome suspensions. Calcif Tissue Int 1987; 41:192-201. [PMID: 3119175 DOI: 10.1007/bf02555238] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Calcium phosphate precipitation can be induced within liposomes containing buffered inorganic phosphate by the ionophore-mediated loading of calcium ions. Negative staining, positive staining for thin sectioning, and freeze-fracture electron microscopy were used to characterize these synthetic vesicles and to evaluate the liposome-mineral interactions resulting from apatite formation. Suspensions of phosphate (0-50 mM KH2PO4)-encapsulated liposomes were prepared from mixtures of phosphatidylcholine, dicetyl phosphate, and cholesterol in the molar ratios of 7:2:1. Precipitation reactions were initiated by first suspending the liposomes in a buffered solution containing calcium (1.3-2.2 mM Ca(NO3)2) and then adding the cationic ionophore X-537A. All experiments were carried out at 22 degrees C, pH 7.4, and 240 mosm. Transmission electron microscopical analysis showed that the liposome preparation consisted of multilamellar, multicompartmental vesicular structures. The liposomes were typically heterogeneous with respect to both the size and number of phospholipid bilayers surrounding the aqueous cores. In Ca-loaded liposomes, discrete clusters of apatite mineral were present within the lumen, and in close proximity to the inner lipid membranes. These nascent crystallites eventually penetrated the lipid envelope to provide a focus for external precipitation events. Crystalline apatite phases were not observed when the incubation conditions prevented intraliposomal precipitation. The de novo calcification of these liposomes had many features in common with the sequence of mineral deposition occurring in matrix vesicle-mediated calcification. These results reinforce the conclusions of earlier chemical and kinetic studies and further support the use of this system as an experimental model for examining the membrane-mineral interactions associated with tissue mineralization.
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Affiliation(s)
- B R Heywood
- Bone Research Branch, National Institute of Dental Research, Bethesda, Maryland 20892
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Eanes ED, Hailer AW. Calcium phosphate precipitation in aqueous suspensions of phosphatidylserine-containing anionic liposomes. Calcif Tissue Int 1987; 40:43-8. [PMID: 3103899 DOI: 10.1007/bf02555727] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Liposomes prepared from 6.3:1.8:0.9:1.0 molar mixtures of phosphatidylcholine, dicetyl phosphate, cholesterol, and phosphatidylserine, respectively, (PS(+) liposomes) were compared with similarly prepared liposomes without the phosphatidylserine (PS(-) liposomes) for their effect on calcium phosphate precipitate formation in aqueous solutions at pH 7.4 and 22 degrees C. The liposomes, encapsulated with 50 mM phosphate (PI), were suspended in buffered 2.2 mM CaCl2, 0 or 1.5 mM KH2PO4 solutions and made permeable to Ca2+ fluxes with the ionophore, X-537A. External solution Ca2+ losses were found to be small in both PS(+) and PS(-) liposome suspensions when no ionophore was added. Even with 1.5 mM PI in the external solution, these losses did not exceed 0.2 mM. However, inoculating both liposome preparations with X-537A resulted in rapid, appreciable losses in solution Ca2+. Previous studies showed that in PS(-) liposomes, these latter losses were due to calcium phosphate precipitation, with the precipitate confined to the interior of the liposomes when no external PI was present, but extending to outside the liposomes when the suspending medium was rendered metastable. In the present study, Ca2+ losses resulting from intraliposomally confined precipitation were found to be marginally greater in PS(+) liposomes due primarily to a larger volume of entrapped PI available for reaction in these liposomes. However, with the addition of PI to the external solution, the reverse was observed, i.e., considerably less Ca2+ was lost in PS(+) than in PS(-) suspensions, a result of markedly less X-537A-induced precipitate forming outside PS(+) liposomes.(ABSTRACT TRUNCATED AT 250 WORDS)
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