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Sedaghat F, Mahamed P, Sultani AS, Bagherian M, Biglari M, Mohammadzadeh A, Ghasemzadeh S, Barati G, Saburi E. Revisiting Recent Tissue Engineering Technologies in Alveolar Cleft Reconstruction. Curr Stem Cell Res Ther 2024; 19:840-851. [PMID: 37461350 DOI: 10.2174/1574888x18666230717152556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 05/06/2023] [Accepted: 06/05/2023] [Indexed: 05/15/2024]
Abstract
Tissue engineering and regenerative medicine have received significant attention in treating degenerative disorders and presented unique opportunities for researchers. The latest research on tissue engineering and regenerative medicine to reconstruct the alveolar cleft has been reviewed in this study. Three approaches have been used to reconstruct alveolar cleft: Studies that used only stem cells or biomaterials and studies that reconstructed alveolar defects by tissue engineering using a combination of stem cells and biomaterials. Stem cells, biomaterials, and tissue-engineered constructs have shown promising results in the reconstruction of alveolar defects. However, some contrary issues, including stem cell durability and scaffold stability, were also observed. It seems that more prospective and comprehensive studies should be conducted to fully clarify the exact dimensions of the stem cells and tissue engineering reconstruction method in the therapy of alveolar cleft.
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Affiliation(s)
- Faraz Sedaghat
- School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Parham Mahamed
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | | | - Mobina Bagherian
- School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Biglari
- Faculty of Dentistry, Iran University of Medical Sciences, Tehran, Iran
| | - Anisa Mohammadzadeh
- Faculty of Dentistry, Babol University of Medical Sciences, Mazandaran, Iran
| | | | | | - Ehsan Saburi
- Medical Genetics Research center, Mashhad University of medical Sciences, Mashhad, Iran
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2
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Molecular and biochemical approach for understanding the transition of amorphous to crystalline calcium phosphate deposits in human teeth. Dent Mater 2022; 38:2014-2029. [DOI: 10.1016/j.dental.2022.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/07/2022] [Accepted: 11/11/2022] [Indexed: 11/23/2022]
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Hypoxia mimetics restore bone biomineralisation in hyperglycaemic environments. Sci Rep 2022; 12:13944. [PMID: 35977987 PMCID: PMC9385857 DOI: 10.1038/s41598-022-18067-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/04/2022] [Indexed: 11/08/2022] Open
Abstract
Diabetic patients have an increased risk of fracture and an increased occurrence of impaired fracture healing. Diabetic and hyperglycaemic conditions have been shown to impair the cellular response to hypoxia, via an inhibited hypoxia inducible factor (HIF)-1α pathway. We investigated, using an in vitro hyperglycaemia bone tissue engineering model (and a multidisciplinary bone characterisation approach), the differing effects of glucose levels, hypoxia and chemicals known to stabilise HIF-1α (CoCl2 and DMOG) on bone formation. Hypoxia (1% O2) inhibited bone nodule formation and resulted in discrete biomineralisation as opposed to the mineralised extracellular collagen fibres found in normoxia (20% O2). Unlike hypoxia, the use of hypoxia mimetics did not prevent nodule formation in normal glucose level. Hyperglycaemic conditions (25 mM and 50 mM glucose) inhibited biomineralisation. Interestingly, both hypoxia mimetics (CoCl2 and DMOG) partly restored hyperglycaemia inhibited bone nodule formation. These results highlight the difference in osteoblast responses between hypoxia mimetics and actual hypoxia and suggests a role of HIF-1α stabilisation in bone biomineralisation that extends that of promoting neovascularisation, or other system effects associated with hypoxia and bone regeneration in vivo. This study demonstrates that targeting the HIF pathway may represent a promising strategy for bone regeneration in diabetic patients.
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Alkaabi SA, Kalla DSN, Alsabri GA, Fauzi A, Jansen N, Tajrin A, Nurrahma R, Müller W, Schröder HC, Xiaohong W, Forouzanfar T, Helder MN, Ruslin M. Safety and feasibility study of using polyphosphate (PolyP) in alveolar cleft repair: a pilot study. Pilot Feasibility Stud 2021; 7:199. [PMID: 34749808 PMCID: PMC8573762 DOI: 10.1186/s40814-021-00939-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 10/28/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Bone grafting is an important surgical procedure to reconstruct alveolar bone defects in patients with cleft lip and palate. Polyphosphate (PolyP) is a physiological polymer present in the blood, primarily in platelets. PolyP plays a role as a phosphate source in bone calcium phosphate deposition. Moreover, the cleavage of high-energy bonds to release phosphates provides local energy necessary for regenerative processes. In this study, polyP is complexed with calcium to form Calcium polyP microparticles (Ca-polyP MPs), which were shown to have osteoinductive properties in preclinical studies. The aim of this study was to evaluate the feasibility, safety, and osteoinductivity of Ca-polyP MPs, alone or in combination with BCP, in a first-in-human clinical trial. METHODS This single-blinded, parallel, prospective clinical pilot study enrolled eight adolescent patients (mean age 18.1: range 13-34 years) with residual alveolar bone cleft. Randomization in two groups (four receiving Ca-polyP MPs only, four a combination of Ca-polyP MPs and biphasic calcium phosphate (BCP)) was performed. Patient follow-up was 6 months. Outcome parameters included safety parameters and close monitoring of possible adverse effects using radiographic imaging, regular blood tests, and physical examinations. Osteoinductivity evaluation using histomorphometric analysis of biopsies was not possible due to COVID restrictions. RESULTS Due to surgical and feasibility reasons, eventually, only 2 patients received Ca-polyP MPs, and the others the combination graft. All patients were assessed up to day 90. Four out of eight were able to continue with the final assessment day (day 180). Three out of eight were unable to reach the hospital due to COVID-19 restrictions. One patient decided not to continue with the study. None of the patients showed any allergic reactions or any remarkable local or systematic side effects. Radiographically, patients receiving Ca-polyP MPs only were scored grade IV Bergland scale, while patients who got the BCP/Ca-polyP MPs combination had scores ranging from I to III. CONCLUSIONS Our results indicate that Ca-polyP MPs and the BCP/Ca-polyP MPs combination appear to be safe graft materials; however, in the current setting, Ca-polyP MPs alone may not be a sufficiently stable defect-filling scaffold to be used in alveolar cleft repair. TRIAL REGISTRATION Indonesian Trial Registry under number INA-EW74C1N by the ethical committee of Faculty of Medicine, Hasanuddin University, Makassar, Indonesia with code number 1063/UN4.6.4.5.31/PP36/2019 .
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Affiliation(s)
- Salem A Alkaabi
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands.
- Department of Oral and Maxillofacial Surgery, Fujairah Hospital, Ministry of Health, Fujairah, United Arab Emirates.
| | - Diandra Sabrina Natsir Kalla
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
- Department of Biochemistry, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Ghamdan A Alsabri
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Abul Fauzi
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia
| | - Nova Jansen
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Andi Tajrin
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia
| | - Rifaat Nurrahma
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
- Department of Prosthodontic, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia
| | - Werner Müller
- Institute for Physiological Chemistry, University Medical Center, University Mainz, Mainz, Germany
- Institute NanotecMARIN GmbH, Mainz, Germany
| | - Heinz C Schröder
- Institute for Physiological Chemistry, University Medical Center, University Mainz, Mainz, Germany
- Institute NanotecMARIN GmbH, Mainz, Germany
| | - Wang Xiaohong
- Institute for Physiological Chemistry, University Medical Center, University Mainz, Mainz, Germany
- Institute NanotecMARIN GmbH, Mainz, Germany
| | - Tymour Forouzanfar
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia
| | - Marco N Helder
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Centers and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia
| | - Muhammad Ruslin
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Hasanuddin University, Makassar, Indonesia.
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Boyineni J, Sredni ST, Margaryan NV, Demirkhanyan L, Tye M, Johnson R, Gonzalez-Nilo F, Hendrix MJC, Pavlov E, Soares MB, Zakharian E, Malchenko S. Inorganic polyphosphate as an energy source in tumorigenesis. Oncotarget 2020; 11:4613-4624. [PMID: 33400735 PMCID: PMC7747861 DOI: 10.18632/oncotarget.27838] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 11/20/2020] [Indexed: 11/25/2022] Open
Abstract
Cancer cells have high demands for energy to maintain their exceedingly proliferative growth. However, the mechanism of energy expenditure in cancer is not well understood. We hypothesize that cancer cells might utilize energy-rich inorganic polyphosphate (polyP), as energetic reserve. PolyP is comprised of orthophosphates linked by phosphoanhydride bonds, as in ATP. Here, we show that polyP is highly abundant in several types of cancer cells, including brain tumor-initiating cells (BTICs), i.e., stem-like cells derived from a mouse brain tumor model that we have previously described. The polymer is avidly consumed during starvation of the BTICs. Depletion of ATP by inhibiting glycolysis and mitochondrial ATP-synthase (OXPHOS) further decreases the levels of polyP and alters morphology of the cells. Moreover, enzymatic hydrolysis of the polymer impairs the viability of cancer cells and significantly deprives ATP stores. These results suggest that polyP might be utilized as a source of phosphate energy in cancer. While the role of polyP as an energy source is established for bacteria, this finding is the first demonstration that polyP may play a similar role in the metabolism of cancer cells.
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Affiliation(s)
- Jerusha Boyineni
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA
| | - Simone T Sredni
- Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Division of Pediatric Neurosurgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Naira V Margaryan
- Department of Biochemistry, Robert C. Byrd Health Sciences Center and Cancer Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Lusine Demirkhanyan
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA
| | - Michael Tye
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA
| | - Robert Johnson
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA
| | - Fernando Gonzalez-Nilo
- Center for Bioinformatics and Integrative Biology, Universidad Andres Bello, Santiago, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Mary J C Hendrix
- Department of Biology, Shepherd University, Shepherdstown, West Virginia, USA
| | - Evgeny Pavlov
- Department of Molecular Pathobiology, New York University, College of Dentistry, New York, New York, USA
| | - Marcelo B Soares
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA
| | - Eleonora Zakharian
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA.,These authors contributed equally to this work
| | - Sergey Malchenko
- Department of Cancer Biology & Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, USA.,These authors contributed equally to this work
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6
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Khong ML, Li L, Solesio ME, Pavlov EV, Tanner JA. Inorganic polyphosphate controls cyclophilin B-mediated collagen folding in osteoblast-like cells. FEBS J 2020; 287:4500-4524. [PMID: 32056376 DOI: 10.1111/febs.15249] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/28/2019] [Accepted: 02/12/2020] [Indexed: 12/13/2022]
Abstract
Evidence is emerging that inorganic polyphosphate (polyP) is a fundamental molecule involved in a wide range of biological processes. In higher eukaryotes, polyP is abundant in osteoblasts but questions remain as to its functions. Here, we find that polyP is particularly enriched in endoplasmic reticulum (ER) where it colocalizes with cyclophilin B (CypB) using osteoblastic SaOS-2 model cell line. PolyP binds directly and specifically to CypB, inhibiting its peptidyl-prolyl cis-trans isomerase activity which is critical for collagen folding. PolyP sequestration by spermine and ER-specific polyP reduction by polyphosphatase expression in cells reduced collagen misfolding and confirmed that endogenous polyP acts as a molecular control of CypB-mediated collagen folding. We propose that polyP is a previously unrecognized critical regulator of protein homeostasis in ER.
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Affiliation(s)
- Mei Li Khong
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, China
| | - Lina Li
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, China
| | - Maria E Solesio
- Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, NY, USA
| | - Evgeny V Pavlov
- Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, NY, USA
| | - Julian A Tanner
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, China
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7
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Al Hegy A, Smith R, Gauthier ER, Gray-Munro JE. Investigation of a cyanine dye assay for the evaluation of the biocompatibility of magnesium alloys by direct and indirect methods. Bioact Mater 2020; 5:26-33. [PMID: 31956733 PMCID: PMC6957867 DOI: 10.1016/j.bioactmat.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/06/2019] [Accepted: 12/07/2019] [Indexed: 12/27/2022] Open
Abstract
Magnesium and its alloys are promising candidates for a new generation of biodegradable metals in orthopaedic applications due to their excellent biocompatibility, biodegradability, and mechanical properties that are similar to natural bone. However, direct in vitro assessment of these materials in the presence of cells is complicated by degradation products from the alloy that lead to a false positive for the most commonly used cell adhesion and cell proliferation assays. In this paper, a cyanine dye was used to quantitatively evaluate the in vitro biocompatibility of a Mg AZ31 alloy by both direct and indirect methods. The cytotoxicity of the corrosion products was evaluated via an indirect method; a 25% decrease in cell viability compared to control samples was observed. Moreover, direct assessment of cell adhesion and proliferation showed a statistically significant increase in cell number at the surface after 72 h. In addition, the degradation rate and surface characteristics of the Mg AZ31 alloy were evaluated for both direct and indirect tests. The degradation rate was unaffected by the presence of cells while evidence of an increase in calcium phosphate deposition on the magnesium alloy surface in the presence of cells was observed. This study demonstrates that a cyanine dye based assay provides a more accurate assessment of the overall in vitro biocompatibility of biodegradable metals than the more commonly used assays reported in the literature to date. Quantitative analysis of cell numbers on the surface of magnesium has been performed. No false positive was observed. Cyanine dye assays are an excellent alternative to tetrazolium salts for in vitro evaluation of bioabsorbable implants.
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Affiliation(s)
- Afrah Al Hegy
- Dept. of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Ryan Smith
- Dept. of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Eric R Gauthier
- Dept. of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
| | - Joy E Gray-Munro
- Dept. of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
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8
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Jarolimova P, Voltrova B, Blahnova V, Sovkova V, Pruchova E, Hybasek V, Fojt J, Filova E. Mesenchymal stem cell interaction with Ti6Al4V alloy pre-exposed to simulated body fluid. RSC Adv 2020; 10:6858-6872. [PMID: 35493900 PMCID: PMC9049760 DOI: 10.1039/c9ra08912h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/13/2020] [Indexed: 11/21/2022] Open
Abstract
Titanium and its alloys are widely used for substitution of hard tissues, especially in orthopaedic and dental surgery. Despite the benefit of the use of titanium for such applications, there are still questions which must be sorted out. Surface properties are crucial for cell adhesion, proliferation and differentiation. Mainly, micro/nanostructured surfaces positively influence osteogenic differentiation of human mesenchymal stem cells. Ti6Al4V is a biocompatible α + β alloy which is widely used in orthopaedics. The aim of this study was to investigate the interaction of the nanostructured and ground Ti6Al4V titanium alloys with simulated body fluid complemented by the defined precipitation of hydroxyapatite-like coating and to study the cytotoxicity and differentiation capacity of cells with such a modified titanium alloy. Nanostructures were fabricated using electrochemical oxidation. Human mesenchymal stem cells (hMSC) were used to evaluate cell adhesion, metabolic activity and proliferation on the specimens. The differentiation potential of the samples was investigated using PCR and specific staining of osteogenic markers collagen type I and osteocalcin. Our results demonstrate that both pure Ti6Al4V, nanostructured samples, and hydroxyapatite-like coating supported hMSC growth and metabolic activity. Nanostructured samples improved collagen type I synthesis after 14 days, while both nanostructured and hydroxyapatite-like coated samples enhanced collagen synthesis on day 21. Osteocalcin synthesis was the most enhanced by hydroxyapatite-like coating on the nanostructured surfaces. Our results indicate that hydroxyapatite-like coating is a useful tool guiding hMSC osteogenic differentiation. Titanium and its alloys are widely used for substitution of hard tissues, especially in orthopaedic and dental surgery.![]()
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Affiliation(s)
- Petra Jarolimova
- Department of Metals and Corrosion Engineering
- Faculty of Chemical Technology
- University of Chemistry and Technology
- 166 28 Prague
- Czech Republic
| | - Barbora Voltrova
- Department of Tissue Engineering
- Institute of Experimental Medicine of the Czech Academy of Sciences
- Prague 4
- Czech Republic
- Faculty of Science
| | - Veronika Blahnova
- Department of Tissue Engineering
- Institute of Experimental Medicine of the Czech Academy of Sciences
- Prague 4
- Czech Republic
- Second Faculty of Medicine
| | - Vera Sovkova
- Department of Tissue Engineering
- Institute of Experimental Medicine of the Czech Academy of Sciences
- Prague 4
- Czech Republic
- University Centre for Energy Efficient Buildings
| | - Eva Pruchova
- Department of Metals and Corrosion Engineering
- Faculty of Chemical Technology
- University of Chemistry and Technology
- 166 28 Prague
- Czech Republic
| | - Vojtech Hybasek
- Department of Metals and Corrosion Engineering
- Faculty of Chemical Technology
- University of Chemistry and Technology
- 166 28 Prague
- Czech Republic
| | - Jaroslav Fojt
- Department of Metals and Corrosion Engineering
- Faculty of Chemical Technology
- University of Chemistry and Technology
- 166 28 Prague
- Czech Republic
| | - Eva Filova
- Department of Tissue Engineering
- Institute of Experimental Medicine of the Czech Academy of Sciences
- Prague 4
- Czech Republic
- Second Faculty of Medicine
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Hughes EAB, Robinson TE, Bassett DB, Cox SC, Grover LM. Critical and diverse roles of phosphates in human bone formation. J Mater Chem B 2019; 7:7460-7470. [PMID: 31729501 DOI: 10.1039/c9tb02011j] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Humans utilise biomineralisation in the formation of bone and teeth. Human biomineralisation processes are defined by the transformation of an amorphous phosphate-based precursor to highly organised nanocrystals. Interestingly, ionic phosphate species not only provide a fundamental building block of biological mineral, but rather exhibit several diverse roles in mediating mineral formation in the physiological milieu. In this review, we focus on elucidating the complex roles of phosphate ions and molecules within human biomineralisation pathways, primarily referring to the nucleation and crystallisation of bone mineral.
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Affiliation(s)
- Erik A B Hughes
- School of Chemical Engineering, University of Birmingham, B15 2TT, UK. and NIHR Surgical Rec and Microbiology Research Centre, Queen Elizabeth Hospital, Birmingham, UK
| | - Thomas E Robinson
- School of Chemical Engineering, University of Birmingham, B15 2TT, UK.
| | - David B Bassett
- School of Chemical Engineering, University of Birmingham, B15 2TT, UK. and Department of Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Sophie C Cox
- School of Chemical Engineering, University of Birmingham, B15 2TT, UK.
| | - Liam M Grover
- School of Chemical Engineering, University of Birmingham, B15 2TT, UK.
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10
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Progress and Applications of Polyphosphate in Bone and Cartilage Regeneration. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5141204. [PMID: 31346519 PMCID: PMC6620837 DOI: 10.1155/2019/5141204] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/29/2019] [Accepted: 06/11/2019] [Indexed: 02/06/2023]
Abstract
Patients with bone and cartilage defects due to infection, tumors, and trauma are quite common. Repairing bone and cartilage defects is thus a major problem for clinicians. Autologous and artificial bone transplantations are associated with many challenges, such as limited materials and immune rejection. Bone and cartilage regeneration has become a popular research topic. Inorganic polyphosphate (polyP) is a widely occurring biopolymer with high-energy phosphoanhydride bonds that exists in organisms from bacteria to mammals. Much data indicate that polyP acts as a regulator of gene expression in bone and cartilage tissues and exerts morphogenetic effects on cells involved in bone and cartilage formation. Exposure of these cells to polyP leads to the increase of cytokines that promote the differentiation of mesenchymal stem cells into osteoblasts, accelerates the osteoblast mineralization process, and inhibits the differentiation of osteoclast precursors to functionally active osteoclasts. PolyP-based materials have been widely reported in in vivo and in vitro studies. This paper reviews the current cellular mechanisms and material applications of polyP in bone and cartilage regeneration.
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11
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Tolba E, Wang X, Ackermann M, Neufurth M, Muñoz‐Espí R, Schröder HC, Müller WEG. In Situ Polyphosphate Nanoparticle Formation in Hybrid Poly(vinyl alcohol)/Karaya Gum Hydrogels: A Porous Scaffold Inducing Infiltration of Mesenchymal Stem Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1801452. [PMID: 30693187 PMCID: PMC6343068 DOI: 10.1002/advs.201801452] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/16/2018] [Indexed: 04/14/2023]
Abstract
The preparation and characterization of a porous hybrid cryogel based on the two organic polymers, poly(vinyl alcohol) (PVA) and karaya gum (KG), into which polyphosphate (polyP) nanoparticles have been incorporated, are described. The PVA/KG cryogel is prepared by intermolecular cross-linking of PVA via freeze-thawing and Ca2+-mediated ionic gelation of KG to form stable salt bridges. The incorporation of polyP as amorphous nanoparticles with Ca2+ ions (Ca-polyP-NP) is achieved using an in situ approach. The polyP constituent does not significantly affect the viscoelastic properties of the PVA/KG cryogel that are comparable to natural soft tissue. The exposure of the Ca-polyP-NP within the cryogel to medium/serum allows the formation of a biologically active polyP coacervate/protein matrix that stimulates the growth of human mesenchymal stem cells in vitro and provides the cells a suitable matrix for infiltration superior to the polyP-free cryogel. In vivo biocompatibility studies in rats reveal that already two to four weeks after implantation into muscle, the implant regions containing the polyP-KG/PVA material become replaced by initial granulation tissue, whereas the controls are free of any cells. It is proposed that the polyP-KG/PVA cryogel has the potential to become a promising implant material for soft tissue engineering/repair.
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Affiliation(s)
- Emad Tolba
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological ChemistryUniversity Medical Center of the Johannes Gutenberg UniversityDuesbergweg 655128MainzGermany
- Polymers and Pigments DepartmentNational Research CentreDokki12622GizaEgypt
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological ChemistryUniversity Medical Center of the Johannes Gutenberg UniversityDuesbergweg 655128MainzGermany
| | - Maximilian Ackermann
- Institute of Functional and Clinical AnatomyUniversity Medical Center of the Johannes Gutenberg UniversityJohann Joachim Becher Weg 1355099MainzGermany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological ChemistryUniversity Medical Center of the Johannes Gutenberg UniversityDuesbergweg 655128MainzGermany
| | - Rafael Muñoz‐Espí
- Institute of Materials Science (ICMUV)Universitat de ValènciaC/Catedràtic José Beltrán 246980PaternaValènciaSpain
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological ChemistryUniversity Medical Center of the Johannes Gutenberg UniversityDuesbergweg 655128MainzGermany
| | - Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological ChemistryUniversity Medical Center of the Johannes Gutenberg UniversityDuesbergweg 655128MainzGermany
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12
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Long-chain polyphosphate in osteoblast matrix vesicles: Enrichment and inhibition of mineralization. Biochim Biophys Acta Gen Subj 2018; 1863:199-209. [PMID: 30312769 DOI: 10.1016/j.bbagen.2018.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/24/2018] [Accepted: 10/05/2018] [Indexed: 01/17/2023]
Abstract
BACKGROUND Inorganic polyphosphate (polyP) is a fundamental and ubiquitous molecule in prokaryotes and eukaryotes. PolyP has been found in mammalian tissues with particularly high levels of long-chain polyP in bone and cartilage where critical questions remain as to its localization and function. Here, we investigated polyP presence and function in osteoblast-like SaOS-2 cells and cell-derived matrix vesicles (MVs), the initial sites of bone mineral formation. METHODS PolyP was quantified by 4',6-diamidino-2-phenylindole (DAPI) fluorescence and characterized by enzymatic methods coupled to urea polyacrylamide gel electrophoresis. Transmission electron microscopy and confocal microscopy were used to investigate polyP localization. A chicken embryo cartilage model was used to investigate the effect of polyP on mineralization. RESULTS PolyP increased in concentration as SaOS-2 cells matured and mineralized. Particularly high levels of polyP were observed in MVs. The average length of MV polyP was determined to be longer than 196 Pi residues by gel chromatography. Electron micrographs of MVs, stained by two polyP-specific staining approaches, revealed polyP localization in the vicinity of the MV membrane. Additional extracellular polyP binds to MVs and inhibits MV-induced hydroxyapatite formation. CONCLUSION PolyP is highly enriched in matrix vesicles and can inhibit apatite formation. PolyP may be hydrolysed to phosphate for further mineralization in the extracellular matrix. GENERAL SIGNIFICANCE PolyP is a unique yet underappreciated macromolecule which plays a critical role in extracellular mineralization in matrix vesicles.
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Müller WEG, Neufurth M, Wang S, Ackermann M, Muñoz-Espí R, Feng Q, Lu Q, Schröder HC, Wang X. Amorphous, Smart, and Bioinspired Polyphosphate Nano/Microparticles: A Biomaterial for Regeneration and Repair of Osteo-Articular Impairments In-Situ. Int J Mol Sci 2018; 19:E427. [PMID: 29385104 PMCID: PMC5855649 DOI: 10.3390/ijms19020427] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/27/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022] Open
Abstract
Using femur explants from mice as an in vitro model, we investigated the effect of the physiological polymer, inorganic polyphosphate (polyP), on differentiation of the cells of the bone marrow in their natural microenvironment into the osteogenic and chondrogenic lineages. In the form of amorphous Ca-polyP nano/microparticles, polyP retains its function to act as both an intra- and extracellular metabolic fuel and a stimulus eliciting morphogenetic signals. The method for synthesis of the nano/microparticles with the polyanionic polyP also allowed the fabrication of hybrid particles with the bisphosphonate zoledronic acid, a drug used in therapy of bone metastases in cancer patients. The results revealed that the amorphous Ca-polyP particles promote the growth/viability of mesenchymal stem cells, as well as the osteogenic and chondrogenic differentiation of the bone marrow cells in rat femur explants, as revealed by an upregulation of the expression of the transcription factors SOX9 (differentiation towards osteoblasts) and RUNX2 (chondrocyte differentiation). In parallel to this bone anabolic effect, incubation of the femur explants with these particles significantly reduced the expression of the gene encoding the osteoclast bone-catabolic enzyme, cathepsin-K, while the expression of the tartrate-resistant acid phosphatase remained unaffected. The gene expression data were supported by the finding of an increased mineralization of the cells in the femur explants in response to the Ca-polyP particles. Finally, we show that the hybrid particles of polyP complexed with zoledronic acid exhibit both the cytotoxic effect of the bisphosphonate and the morphogenetic and mineralization inducing activity of polyP. Our results suggest that the Ca-polyP nano/microparticles are not only a promising scaffold material for repairing long bone osteo-articular damages but can also be applied, as a hybrid with zoledronic acid, as a drug delivery system for treatment of bone metastases. The polyP particles are highlighted as genuine, smart, bioinspired nano/micro biomaterials.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Johann Joachim Becher Weg 13, 55099 Mainz, Germany.
| | - Rafael Muñoz-Espí
- Institute of Materials Science (ICMUV), Universitat de València, C/Catedràtic José Beltrán 2, Paterna, 46980 València, Spain.
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
| | - Qiang Lu
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
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Müller WEG, Ackermann M, Wang S, Neufurth M, Muñoz-Espí R, Feng Q, Schröder HC, Wang X. Inorganic polyphosphate induces accelerated tube formation of HUVEC endothelial cells. Cell Mol Life Sci 2018; 75:21-32. [PMID: 28770290 PMCID: PMC11105250 DOI: 10.1007/s00018-017-2601-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 07/14/2017] [Accepted: 07/24/2017] [Indexed: 12/16/2022]
Abstract
In this study, the effect of inorganic polyphosphate (polyP) on the initial phase of angiogenesis and vascularization was investigated, applying the HUVEC cell tube formation assay. PolyP is a physiological and high energy phosphate polymer which has been proposed to act as a metabolic fuel in the extracellular space with only a comparably low ATP content. The experiments revealed that polyP accelerates tube formation of human umbilical vein endothelial cells (HUVEC), seeded onto a solidified basement membrane extract matrix which contains polyP-metabolizing alkaline phosphatase (ALP) activity. This effect is abolished by co-addition of apyrase, which degrades ATP to AMP and inorganic phosphate. The assumption that ATP, derived from polyP, activates HUVEC cells leading to tube formation was corroborated by experiments showing that addition of polyP to the cells causes a strong rise of ATP level in the culture medium. Finally, we show that at a later stage of cultivation of HUVEC cells, after 3 d, polyP causes a strong enhancement of the expression of the genes encoding for the two major matrix metalloproteinases (MMPs) released by endothelial cells during tube formation, MMP-9 and MMP-2. This stimulatory effect is again abrogated by addition of apyrase together with polyP. From these results, we propose that polyP is involved either directly or indirectly in energy supply, via ALP-mediated transfer of energy-rich phosphate under ATP formation. This ATP is utilized for the activation and oriented migration of endothelial cells and for the matrix organization during the initial phases of tube formation.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Duesbergweg 6, 55128, Mainz, Germany.
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Johann Joachim Becher Weg 13, 55099, Mainz, Germany
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Rafael Muñoz-Espí
- Institute of Materials Science (ICMUV), Universitat de València, C/Catedràtic José, Beltrán 2, Paterna, 46980, València, Spain
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Duesbergweg 6, 55128, Mainz, Germany.
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Wang X, Schröder HC, Müller WEG. Amorphous polyphosphate, a smart bioinspired nano-/bio-material for bone and cartilage regeneration: towards a new paradigm in tissue engineering. J Mater Chem B 2018; 6:2385-2412. [DOI: 10.1039/c8tb00241j] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Physiological amorphous polyphosphate nano/micro-particles, injectable and implantable, attract and stimulate MSCs into implants for tissue regeneration.
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Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- 55128 Mainz
- Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- 55128 Mainz
- Germany
| | - Werner E. G. Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry
- University Medical Center of the Johannes Gutenberg University
- 55128 Mainz
- Germany
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3D printing of hybrid biomaterials for bone tissue engineering: Calcium-polyphosphate microparticles encapsulated by polycaprolactone. Acta Biomater 2017; 64:377-388. [PMID: 28966095 DOI: 10.1016/j.actbio.2017.09.031] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/18/2017] [Accepted: 09/22/2017] [Indexed: 01/08/2023]
Abstract
Here we describe the formulation of a morphogenetically active bio-ink consisting of amorphous microparticles (MP) prepared from Ca2+ and the physiological inorganic polymer, polyphosphate (polyP). Those MP had been fortified by mixing with poly-ε-caprolactone (PCL) to allow 3D-bioprinting. The resulting granular PCL/Ca-polyP-MP hybrid material, liquefied by short-time heating to 100 °C, was used for the 3D-printing of tissue-like scaffolds formed by strands with a thickness of 400 µm and a stacked architecture leaving ≈0.5 mm2-sized open holes enabling cell migration. The printed composite scaffold turned out to combine suitable biomechanical properties (Young's modulus of 1.60 ± 0.1 GPa; Martens hardness of 153 ± 28 MPa), matching those of cortical and trabecular bone, with morphogenetic activity. This scaffold was capable of attracting and promoting the growth of human bone-related SaOS-2 cells as demonstrated by staining for cell viability (Calcein AM), cell density (DRAQ5) and SEM studies. Furthermore, the hybrid material was demonstrated to upregulate the steady-state-expression of the cell migration-inducing chemokine SDF-1α. EDX analysis and FTIR measurements revealed the presence of hydroxyapatite in the mineral deposits formed on the scaffold surface. Based on the results we conclude that granular PCL/Ca-polyP-MP hybrid material is suitable for the fabrication of bioprintable scaffold which comprises not only biomechanical stability but also morphogenetic potential. STATEMENT OF SIGNIFICANCE In present-day regenerative engineering efforts, biomaterial- and cell-based strategies are proposed that meet the required functional and spatial characteristics and variations, especially in the transition regions between soft (cartilage, tendon or ligament) and hard (bone) tissues. In a biomimetic approach we succeeded to fabricate amorphous Ca-polyP nanoparticles/microparticles which are highly biocompatible. Together with polycaprolactone (PCL), polyP can be bio-printed. This hybrid material attracts the cells, as documented optically as well as by a gene-expression studies. Since PCL is already a FDA-approved organic and inert polymer and polyP a physiological biologically active component this new bio-hybrid material has the potential to restore physiological functions, including bone remodelling and regeneration if used as implant.
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Müller WEG, Schröder HC, Wang X. The Understanding of the Metazoan Skeletal System, Based on the Initial Discoveries with Siliceous and Calcareous Sponges. Mar Drugs 2017; 15:E172. [PMID: 28604622 PMCID: PMC5484122 DOI: 10.3390/md15060172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/03/2017] [Accepted: 06/08/2017] [Indexed: 12/25/2022] Open
Abstract
Initiated by studies on the mechanism of formation of the skeletons of the evolutionary oldest still extant multicellular animals, the sponges (phylum Porifera) have provided new insights into the mechanism of formation of the Ca-phosphate/hydroxyapatite skeleton of vertebrate bone. Studies on the formation of the biomineral skeleton of sponges revealed that both the formation of the inorganic siliceous skeletons (sponges of the class of Hexactinellida and Demospongiae) and of the calcareous skeletons (class of Calcarea) is mediated by enzymes (silicatein: polymerization of biosilica; and carbonic anhydrase: deposition of Ca-carbonate). Detailed studies of the initial mineralization steps in human bone-forming cells showed that this process is also controlled by enzymes, starting with the deposition of Ca-carbonate bio-seeds, mediated by carbonic anhydrases-II and -IX, followed by non-enzymatic transformation of the formed amorphous Ca-carbonate deposits into amorphous Ca-phosphate and finally hydroxyapatite crystals. The required phosphate is provided by enzymatic (alkaline phosphatase-mediated) degradation of an inorganic polymer, polyphosphate (polyP), which also acts as a donor for chemically useful energy in this process. These new discoveries allow the development of novel biomimetic strategies for treatment of bone diseases and defects.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
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Wang X, Ackermann M, Neufurth M, Wang S, Schröder HC, Müller WEG. Morphogenetically-Active Barrier Membrane for Guided Bone Regeneration, Based on Amorphous Polyphosphate. Mar Drugs 2017; 15:E142. [PMID: 28513544 PMCID: PMC5450548 DOI: 10.3390/md15050142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/22/2022] Open
Abstract
We describe a novel regeneratively-active barrier membrane which consists of a durable electrospun poly(ε-caprolactone) (PCL) net covered with a morphogenetically-active biohybrid material composed of collagen and inorganic polyphosphate (polyP). The patch-like fibrous collagen structures are decorated with small amorphous polyP nanoparticles (50 nm) formed by precipitation of this energy-rich and enzyme-degradable (alkaline phosphatase) polymer in the presence of calcium ions. The fabricated PCL-polyP/collagen hybrid mats are characterized by advantageous biomechanical properties, such as enhanced flexibility and stretchability with almost unaltered tensile strength of the PCL net. The polyP/collagen material promotes the attachment and increases the viability/metabolic activity of human mesenchymal stem cells compared to cells grown on non-coated mats. The gene expression studies revealed that cells, growing onto polyP/collagen coated mats show a significantly (two-fold) higher upregulation of the steady-state-expression of the angiopoietin-2 gene used as an early marker for wound healing than cells cultivated onto non-coated mats. Based on our results we propose that amorphous polyP, stabilized onto a collagen matrix, might be a promising component of functionally-active barrier membranes for guided tissue regeneration in medicine and dentistry.
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Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Johann Joachim Becher Weg 13, D-55099 Mainz, Germany.
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Shunfeng Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Heinz C Schröder
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
| | - Werner E G Müller
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
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Müller WEG, Ackermann M, Neufurth M, Tolba E, Wang S, Feng Q, Schröder HC, Wang X. A Novel Biomimetic Approach to Repair Enamel Cracks/Carious Damages and to Reseal Dentinal Tubules by Amorphous Polyphosphate. Polymers (Basel) 2017; 9:polym9040120. [PMID: 30970799 PMCID: PMC6432492 DOI: 10.3390/polym9040120] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/23/2017] [Accepted: 03/23/2017] [Indexed: 12/21/2022] Open
Abstract
Based on natural principles, we developed a novel toothpaste, containing morphogenetically active amorphous calcium polyphosphate (polyP) microparticles which are enriched with retinyl acetate ("a-polyP/RA-MP"). The spherical microparticles (average size, 550 ± 120 nm), prepared by co-precipitating soluble Na-polyP with calcium chloride and supplemented with retinyl acetate, were incorporated into a base toothpaste at a final concentration of 1% or 10%. The "a-polyP/RA-MP" ingredient significantly enhanced the stimulatory effect of the toothpaste on the growth of human mesenchymal stem cells (MSC). This increase was paralleled by an upregulation of the MSC marker genes for osteoblast differentiation, collagen type I and alkaline phosphatase. In addition, polyP, applied as Zn-polyP microparticles ("Zn-a-polyP-MP"), showed a distinct inhibitory effect on growth of Streptococcus mutans, in contrast to a toothpaste containing the broad-spectrum antibiotic triclosan that only marginally inhibits this cariogenic bacterium. Moreover, we demonstrate that the "a-polyP/RA-MP"-containing toothpaste efficiently repairs cracks/fissures in the enamel and dental regions and reseals dentinal tubules, already after a five-day treatment (brushing) of teeth as examined by SEM (scanning electron microscopy) and semi-quantitative EDX (energy-dispersive X-ray spectroscopy). The occlusion of the dentin cracks by the microparticles turned out to be stable and resistant against short-time high power sonication. Our results demonstrate that the novel toothpaste prepared here, containing amorphous polyP microparticles enriched with retinyl acetate, is particularly suitable for prevention/repair of (cariogenic) damages of tooth enamel/dentin and for treatment of dental hypersensitivity. While the polyP microparticles function as a sealant for dentinal damages and inducer of remineralization processes, the retinyl acetate acts as a regenerative stimulus for collagen gene expression in cells of the surrounding tissue, the periodontium.
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Affiliation(s)
- Werner E G Müller
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University,Johann Joachim Becher Weg 13, D-55099 Mainz, Germany.
| | - Meik Neufurth
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Emad Tolba
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Shunfeng Wang
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, China.
| | - Heinz C Schröder
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
| | - Xiaohong Wang
- European Research Council-Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany.
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Müller WE, Tolba E, Ackermann M, Neufurth M, Wang S, Feng Q, Schröder HC, Wang X. Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo. Acta Biomater 2017; 50:89-101. [PMID: 28017868 DOI: 10.1016/j.actbio.2016.12.045] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/18/2016] [Accepted: 12/21/2016] [Indexed: 12/31/2022]
Abstract
Here we describe the fabrication process of amorphous strontium-polyphosphate microparticles ("Sr-a-polyP-MP"). The effects of these particles on growth and gene expression were investigated with SaOS-2 cells as well as with human mesenchymal stem cells (MSC) and compared with those particles prepared of amorphous calcium-polyphosphate ("Ca-a-polyP-MP") and of strontium salt. The results revealed a markedly higher stimulation of growth of MSC by "Sr-a-polyP-MP" compared to "Ca-a-polyP-MP" and a significant increase in mineralization of SaOS-2 cells, as well as an enhanced upregulation of the expression of the genes encoding for alkaline phosphatase and the bone morphogenetic protein 2 (BMP-2), likewise performed with SaOS-2 cells. On the other hand, "Sr-a-polyP-MP" only slightly changes the expression of the osteocyte-specific sclerostin, a negative regulator of the canonical Wnt signaling pathway and an inhibitor of bone cell differentiation as well as of mineralization in SaOS-2 cells. In contrast, "Ca-a-polyP-MP" strongly increased the steady-state expression of the SOST (sclerostin) gene. In animal studies poly(d,l-lactide-co-glycolide (PLGA) microspheres, containing polyP particles, were implanted into critical-size calvarial defects in rats. The results show that the amorphous Sr-polyP-containing microspheres caused an increased healing/mineralization of the bone defect even after short implantation periods of 8-12weeks, if compared to the β-tri-calcium phosphate control as well as to Ca-polyP. It is proposed that "Sr-a-polyP-MP" might elicit suitable properties to be applied as a regeneratively active implant material for bone repair. STATEMENT OF SIGNIFICANCE In this manuscript, we fabricated amorphous strontium-polyphosphate microparticles ("Sr-a-polyP-MP") and studied their effects on bone mineral formation in vitro as well as in vivo. In vitro, those particles substantially increased the expression of the genes encoding for alkaline phosphatase, the bone morphogenetic protein 2 and the mineralization. In vivo, the "Sr-a-polyP-MP" packed into PLGA microspheres and implanted into critical-size calvarial defects in rats resulted in a speeded up of the healing/mineralization of the bone defect. Those properties qualify Sr-a-polyP as a suitable biomaterial for bone regenerative implants.
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Biocalcite and Carbonic Acid Activators. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017. [PMID: 28238040 DOI: 10.1007/978-3-319-51284-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Based on evolution of biomineralizing systems and energetic considerations, there is now compelling evidence that enzymes play a driving role in the formation of the inorganic skeletons from the simplest animals, the sponges, up to humans. Focusing on skeletons based on calcium minerals, the principle enzymes involved are the carbonic anhydrase (formation of the calcium carbonate-based skeletons of many invertebrates like the calcareous sponges, as well as deposition of the calcium carbonate bioseeds during human bone formation) and the alkaline phosphatase (providing the phosphate for bone calcium phosphate-hydroxyapatite formation). These two enzymes, both being involved in human bone formation, open novel not yet exploited targets for pharmacological intervention of human bone diseases like osteoporosis, using compounds that act as activators of these enzymes. This chapter focuses on carbonic anhydrases of biomedical interest and the search for potential activators of these enzymes, was well as the interplay between carbonic anhydrase-mediated calcium carbonate bioseed synthesis and metabolism of energy-rich inorganic polyphosphates. Beyond that, the combination of the two metabolic products, calcium carbonate and calcium-polyphosphate, if applied in an amorphous form, turned out to provide the basis for a new generation of scaffold materials for bone tissue engineering and repair that are, for the first time, morphogenetically active.
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Müller WEG, Wang X, Schröder HC. New Target Sites for Treatment of Osteoporosis. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 55:187-219. [PMID: 28238039 DOI: 10.1007/978-3-319-51284-6_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the last few years, much progress has been achieved in the discovery of new drug target sites for treatment of osteoporotic disorders, one of the main challenging diseases with a large burden for the public health systems. Among these new agents promoting bone formation, shifting the impaired equilibrium between bone anabolism and bone catabolism in the direction of bone synthesis are inorganic polymers, in particular inorganic polyphosphates that show strong stimulatory effects on the expression of bone anabolic marker proteins and hydroxyapatite formation. The bone-forming activity of these polymers can even be enhanced by combination with certain small molecules like quercetin, or if given as functionally active particles with certain divalent cations like strontium ions even showing by itself biological activity. This chapter summarizes recent developments in the search and development of novel anti-osteoporotic agents, with a particular focus on therapeutic approaches based on the potential application of inorganic polymers and combinations.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany. .,NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany.
| | - Xiaohong Wang
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.,NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany
| | - Heinz C Schröder
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.,NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany
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Schröder HC, Tolba E, Diehl-Seifert B, Wang X, Müller WEG. Electrospinning of Bioactive Wound-Healing Nets. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 55:259-290. [PMID: 28238041 DOI: 10.1007/978-3-319-51284-6_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The availability of appropriate dressings for treatment of wounds, in particular chronic wounds, is a task that still awaits better solutions than provided by currently applied materials. The method of electrospinning enables the fabrication of novel materials for wound dressings due to the high surface area and porosity of the electrospun meshes and the possibility to include bioactive ingredients. Recent results show that the incorporation of biologically active inorganic polyphosphate microparticles and microspheres and synergistically acting retinoids into electrospun polymer fibers yields biocompatible and antibacterial mats for potential dressings with improved wound-healing properties. The underlying principles and the mechanism of these new approaches in the therapy wounds, in particular wounds showing impaired healing, as well as for further applications in skin regeneration/repair, are summarized.
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Affiliation(s)
- Heinz C Schröder
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
- NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany.
| | - Emad Tolba
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
| | - Bärbel Diehl-Seifert
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
- NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany
- NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany
| | - Werner E G Müller
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128, Mainz, Germany.
- NanotecMARIN GmbH, Duesbergweg 6, 55128, Mainz, Germany.
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Lui ELH, Ao CKL, Li L, Khong ML, Tanner JA. Inorganic polyphosphate triggers upregulation of interleukin 11 in human osteoblast-like SaOS-2 cells. Biochem Biophys Res Commun 2016; 479:766-771. [PMID: 27693781 DOI: 10.1016/j.bbrc.2016.09.137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 09/26/2016] [Indexed: 02/03/2023]
Abstract
Polyphosphate (polyP) is abundant in bone but its roles in signaling and control of gene expression remain unclear. Here, we investigate the effect of extracellular polyP on proliferation, migration, apoptosis, gene and protein expression in human osteoblast-like SaOS-2 cells. Extracellular polyP promoted SaOS-2 cell proliferation, increased rates of migration, inhibited apoptosis and stimulated the rapid phosphorylation of extracellular-signal-regulated kinase (ERK) directly through basic fibroblast growth factor receptor (bFGFR). cDNA microarray revealed that polyP induced significant upregulation of interleukin 11 (IL-11) at both RNA and protein levels.
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Affiliation(s)
- Eric Lik-Hang Lui
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Carl Ka-Leong Ao
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Lina Li
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Mei-Li Khong
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Julian Alexander Tanner
- School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
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Cell interaction with modified nanotubes formed on titanium alloy Ti-6Al-4V. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 65:313-22. [DOI: 10.1016/j.msec.2016.04.037] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/29/2016] [Accepted: 04/11/2016] [Indexed: 01/28/2023]
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Nitiputri K, Ramasse QM, Autefage H, McGilvery CM, Boonrungsiman S, Evans ND, Stevens MM, Porter AE. Nanoanalytical Electron Microscopy Reveals a Sequential Mineralization Process Involving Carbonate-Containing Amorphous Precursors. ACS NANO 2016; 10:6826-35. [PMID: 27383526 PMCID: PMC5404715 DOI: 10.1021/acsnano.6b02443] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A direct observation and an in-depth characterization of the steps by which bone mineral nucleates and grows in the extracellular matrix during the earliest stages of maturation, using relevant biomineralization models as they grow into mature bone mineral, is an important research goal. To better understand the process of bone mineralization in the extracellular matrix, we used nanoanalytical electron microscopy techniques to examine an in vitro model of bone formation. This study demonstrates the presence of three dominant CaP structures in the mineralizing osteoblast cultures: <80 nm dense granules with a low calcium to phosphate ratio (Ca/P) and crystalline domains; calcium phosphate needles emanating from a focus: "needle-like globules" (100-300 nm in diameter) and mature mineral, both with statistically higher Ca/P compared to that of the dense granules. Many of the submicron granules and globules were interspersed around fibrillar structures containing nitrogen, which are most likely the signature of the organic phase. With high spatial resolution electron energy loss spectroscopy (EELS) mapping, spatially resolved maps were acquired showing the distribution of carbonate within each mineral structure. The carbonate was located in the middle of the granules, which suggested the nucleation of the younger mineral starts with a carbonate-containing precursor and that this precursor may act as seed for growth into larger, submicron-sized, needle-like globules of hydroxyapatite with a different stoichiometry. Application of analytical electron microscopy has important implications in deciphering both how normal bone forms and in understanding pathological mineralization.
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Affiliation(s)
- Kharissa Nitiputri
- Department of Materials, Imperial College London, London SW7 2AZ UK
- Department of Bioengineering, Imperial College London, London SW7 2AZ UK
- Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ UK
| | | | - Hélène Autefage
- Department of Materials, Imperial College London, London SW7 2AZ UK
- Department of Bioengineering, Imperial College London, London SW7 2AZ UK
- Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ UK
| | | | - Suwimon Boonrungsiman
- Department of Materials, Imperial College London, London SW7 2AZ UK
- Department of Bioengineering, Imperial College London, London SW7 2AZ UK
- Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ UK
| | - Nicholas D. Evans
- Department of Bioengineering and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ
| | - Molly M. Stevens
- Department of Materials, Imperial College London, London SW7 2AZ UK
- Department of Bioengineering, Imperial College London, London SW7 2AZ UK
- Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ UK
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Lomelino C, McKenna R. Carbonic anhydrase inhibitors: a review on the progress of patent literature (2011-2016). Expert Opin Ther Pat 2016; 26:947-56. [PMID: 27387065 DOI: 10.1080/13543776.2016.1203904] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION A large area of carbonic anhydrase (CA) research focuses on the inhibition of human CA IX and CA XII, as these isoforms have been designated as biomarkers and therapeutic targets for various cancer types. AREAS COVERED Recently, the majority of CA inhibitor (CAI) patents cover compound design, synthesis, and delivery methods for the treatment of glaucoma and cancer. The analysis of included patents highlights the need for isoform specific inhibitors. This review covers the patents of medically relevant carbonic anhydrase inhibitors between 2011-2016. EXPERT OPINION The improvement of structure-based drug design methods and access to the crystal structures of human CA isoforms have improved inhibitor development. This progress can be observed in relation to the selective inhibition of CA IX for cancer treatments, with one inhibitor in clinical trials. However, the design of nonclassical CAIs is essential to further improve isoform specificity and prevent sulfur allergies.
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Affiliation(s)
- Carrie Lomelino
- a Department of Biochemistry and Molecular Biology , College of Medicine, University of Florida , Gainesville , FL , USA
| | - Robert McKenna
- a Department of Biochemistry and Molecular Biology , College of Medicine, University of Florida , Gainesville , FL , USA
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Wang X, Ackermann M, Wang S, Tolba E, Neufurth M, Feng Q, Schröder HC, Müller WEG. Amorphous polyphosphate/amorphous calcium carbonate implant material with enhanced bone healing efficacy in a critical-size defect in rats. ACTA ACUST UNITED AC 2016; 11:035005. [PMID: 27147677 DOI: 10.1088/1748-6041/11/3/035005] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this study the effect of amorphous calcium carbonate (ACC) microparticles and amorphous calcium polyphosphate (polyP) microparticles (termed aCa-polyP-MP) on bone mineral forming cells/tissue was investigated in vitro and in vivo. The ACC particles (termed ACC-P10-MP) were prepared in the presence of Na-polyP. Only the combinations of polyP and ACC microparticles enhanced the proliferation rate of human mesenchymal stem cells (MSCs). Gene expression studies revealed that ACC causes an upregulation of the expression of the cell membrane-associated carbonic anhydrase IX (CA IX; formation of ACC), while the transcript level of the alkaline phosphatase (ALP; liberation of orthophosphate from polyP) changes only relatively little. In contrast, aCa-polyP-MP primarily induces ALP expression. If both components are applied together a strong stimulation of expression of both marker genes is observed. In order to investigate whether ACC also enhances bone regeneration induced by polyP in vivo, the particles were encapsulated into PLGA (poly(d,l-lactide-co-glycolide)) microspheres (diameter ~800 μm) and implanted into rat critical-size calvarial defects. The studies revealed that animals that received aCa-polyP-MP microspheres showed an increased rate of regeneration compared to β-tri-calcium phosphate (β-TCP) controls. This effect is even accelerated if microspheres with both aCa-polyP-MP and ACC-P10-MP (1 : 1 weight ratio) are applied, resulting in an almost complete restoration of the defect area after 12 weeks. qRT-PCR analyses of tissue sections through the regeneration zone with microspheres containing both aCa-polyP-MP and ACC-P10-MP revealed a significantly higher upregulation of expression of the marker genes compared to each of the components alone. The Young's moduli for microspheres containing aCa-polyP-MP (1.74 MPa) and aCa-polyP-MP/ACC-P10-MP (2.38 MPa) were markedly higher compared to β-TCP-controls (0.63 mPa). Our results show that the combined application of ACC and Ca-polyP (both in the amorphous state) opens new strategies for the development of regenerative implants for the reconstruction of bone defects.
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Affiliation(s)
- Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
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