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Meng F, Yin Z, Ren X, Geng Z, Su J. Construction of Local Drug Delivery System on Titanium-Based Implants to Improve Osseointegration. Pharmaceutics 2022; 14:pharmaceutics14051069. [PMID: 35631656 PMCID: PMC9146791 DOI: 10.3390/pharmaceutics14051069] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/01/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
Titanium and its alloys are the most widely applied orthopedic and dental implant materials due to their high biocompatibility, superior corrosion resistance, and outstanding mechanical properties. However, the lack of superior osseointegration remains the main obstacle to successful implantation. Previous traditional surface modification methods of titanium-based implants cannot fully meet the clinical needs of osseointegration. The construction of local drug delivery systems (e.g., antimicrobial drug delivery systems, anti-bone resorption drug delivery systems, etc.) on titanium-based implants has been proved to be an effective strategy to improve osseointegration. Meanwhile, these drug delivery systems can also be combined with traditional surface modification methods, such as anodic oxidation, acid etching, surface coating technology, etc., to achieve desirable and enhanced osseointegration. In this paper, we review the research progress of different local drug delivery systems using titanium-based implants and provide a theoretical basis for further research on drug delivery systems to promote bone–implant integration in the future.
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Affiliation(s)
- Fanying Meng
- Institute of Translational Medicine, Shanghai University, Shanghai 200444, China;
- School of Medicine, Shanghai University, Shanghai 200444, China
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Zhifeng Yin
- Department of Orthopedics, Shanghai Zhongye Hospital, Shanghai 200941, China;
| | - Xiaoxiang Ren
- Institute of Translational Medicine, Shanghai University, Shanghai 200444, China;
- Correspondence: (X.R.); (Z.G.); (J.S.)
| | - Zhen Geng
- Institute of Translational Medicine, Shanghai University, Shanghai 200444, China;
- Correspondence: (X.R.); (Z.G.); (J.S.)
| | - Jiacan Su
- Institute of Translational Medicine, Shanghai University, Shanghai 200444, China;
- Correspondence: (X.R.); (Z.G.); (J.S.)
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2
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Abstract
Implants and their technological advances have been a critical component of musculoskeletal care for almost a century. Modern implants are designed to enhance bone ingrowth, promote soft-tissue healing, and prevent infection. Porous metals and short-stem fixation devices have rendered previously unreconstructable bony deficits reconstructable. Stem cells, growth factors, and novel biocompatible compounds have been designed to promote and enhance soft tissue attachment to implants. Antimicrobial modifications have been engineered onto implants to deter bacterial attachment, and innovative surface modifications and eluting technologies may be in our near future. Yet, given the enormous economic pressures in orthopaedics, marketing claims of innovation often exceed scientific accomplishment. Vigilance is thus required in distinguishing transformational discovery from unsubstantiated claims.
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Abstract
Limb salvage is widely practiced as standard of care in most cases of extremity bone sarcoma. Allograft and endoprosthesis reconstructions are the most widely utilized modalities for the reconstruction of large segment defects, however complication rates remain high. Aseptic loosening and infection remain the most common modes of failure. Implant integration, soft-tissue function, and infection prevention are crucial for implant longevity and function. Macro and micro alterations in implant design are reviewed in this manuscript. Tissue engineering principles using nanoparticles, cell-based, and biological augments have been utilized to develop implant coatings that improve osseointegration and decrease infection. Similar techniques have been used to improve the interaction between soft tissues and implants. Tissue engineered constructs (TEC) used in combination with, or in place of, traditional reconstructive techniques may represent the next major advancement in orthopaedic oncology reconstructive science, although preclinical results have yet to achieve durable translation to the bedside.
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Ong SM, Biswas SK, Wong SC. MicroRNA-mediated immune modulation as a therapeutic strategy in host-implant integration. Adv Drug Deliv Rev 2015; 88:92-107. [PMID: 26024977 DOI: 10.1016/j.addr.2015.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 05/05/2015] [Accepted: 05/21/2015] [Indexed: 12/29/2022]
Abstract
The concept of implanting an artificial device into the human body was once the preserve of science fiction, yet this approach is now often used to replace lost or damaged biological structures in human patients. However, assimilation of medical devices into host tissues is a complex process, and successful implant integration into patients is far from certain. The body's immediate response to a foreign object is immune-mediated reaction, hence there has been extensive research into biomaterials that can reduce or even ablate anti-implant immune responses. There have also been attempts to embed or coat anti-inflammatory drugs and pro-regulatory molecules onto medical devices with the aim of preventing implant rejection by the host. In this review, we summarize the key immune mediators of medical implant reaction, and we evaluate the potential of microRNAs to regulate these processes to promote wound healing, and prolong host-implant integration.
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Affiliation(s)
- Siew-Min Ong
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Level 4, Biopolis, Singapore 138648, Singapore
| | - Subhra K Biswas
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Level 4, Biopolis, Singapore 138648, Singapore
| | - Siew-Cheng Wong
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Level 4, Biopolis, Singapore 138648, Singapore.
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5
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Braem A, De Cremer K, Delattin N, De Brucker K, Neirinck B, Vandamme K, Martens JA, Michiels J, Vleugels J, Cammue BPA, Thevissen K. Novel anti-infective implant substrates: controlled release of antibiofilm compounds from mesoporous silica-containing macroporous titanium. Colloids Surf B Biointerfaces 2015; 126:481-8. [PMID: 25601097 DOI: 10.1016/j.colsurfb.2014.12.054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 12/05/2014] [Accepted: 12/30/2014] [Indexed: 10/24/2022]
Abstract
Bone implants with open porosity enable fast osseointegration, but also present an increased risk of biofilm-associated infections. We design a novel implant material consisting of a mesoporous SiO2 diffusion barrier (pore diameter: 6.4 nm) with controlled drug release functionality integrated in a macroporous Ti load-bearing structure (fully interconnected open porosity: 30%; pore window size: 0.5-2.0 μm). Using an in vitro tool consisting of Ti/SiO2 disks in an insert set-up, through which molecules can diffuse from feed side to release side, a continuous release without initial burst effect of the antibiofilm compound toremifene is sustained for at least 9 days, while release concentrations (up to 17 μM daily) increase with feed concentrations (up to 4mM). Toremifene diffusivity through the SiO2 phase into H2O is estimated around 10(-13)m(2)/s, suggesting configurational diffusion through mesopores. Candida albicans biofilm growth on the toremifene-release side is significantly inhibited, establishing a proof-of-concept for the drug delivery functionality of mesoporous SiO2 incorporated into a high-strength macroporous Ti carrier. Next-generation implants made of this composite material and equipped with an internal reservoir (feed side) can yield long-term controlled release of antibiofilm compounds, effectively treating infections on the implant surface (release side) over a prolonged time.
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Affiliation(s)
- Annabel Braem
- Department of Materials Engineering (MTM), KU Leuven, Kasteelpark Arenberg 44 Box 2450, 3001 Leuven, Belgium.
| | - Kaat De Cremer
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium; Department of Plant Systems Biology, VIB, Technologiepark 927, 9052 Ghent, Belgium.
| | - Nicolas Delattin
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium.
| | - Katrijn De Brucker
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium.
| | - Bram Neirinck
- Department of Materials Engineering (MTM), KU Leuven, Kasteelpark Arenberg 44 Box 2450, 3001 Leuven, Belgium.
| | - Katleen Vandamme
- BIOMAT Research Cluster, Department of Oral Health Sciences and Prosthetic Dentistry, KU Leuven and University Hospitals Leuven, Kapucijnenvoer 7 Box 7001, 3000 Leuven, Belgium.
| | - Johan A Martens
- Centre of Surface Chemistry and Catalysis (COK), KU Leuven, Kasteelpark Arenberg 23 Box 2461, 3001 Leuven, Belgium.
| | - Jan Michiels
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium.
| | - Jef Vleugels
- Department of Materials Engineering (MTM), KU Leuven, Kasteelpark Arenberg 44 Box 2450, 3001 Leuven, Belgium.
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium; Department of Plant Systems Biology, VIB, Technologiepark 927, 9052 Ghent, Belgium.
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Kasteelpark Arenberg 20 Box 2460, 3001 Leuven, Belgium.
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Jung HD, Jang TS, Wang L, Kim HE, Koh YH, Song J. Novel strategy for mechanically tunable and bioactive metal implants. Biomaterials 2015; 37:49-61. [DOI: 10.1016/j.biomaterials.2014.10.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/02/2014] [Indexed: 01/15/2023]
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7
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Lewallen EA, Riester SM, Bonin CA, Kremers HM, Dudakovic A, Kakar S, Cohen RC, Westendorf JJ, Lewallen DG, van Wijnen AJ. Biological strategies for improved osseointegration and osteoinduction of porous metal orthopedic implants. TISSUE ENGINEERING PART B-REVIEWS 2014; 21:218-30. [PMID: 25348836 DOI: 10.1089/ten.teb.2014.0333] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant-bone interface and thereby improve long-term clinical outcomes.
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8
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Rapuano BE, Singh H, Boskey AL, Doty SB, MacDonald DE. Heat and radiofrequency plasma glow discharge pretreatment of a titanium alloy: evidence [corrected] for enhanced osteoinductive properties. J Cell Biochem 2013; 114:1917-27. [PMID: 23494951 DOI: 10.1002/jcb.24536] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 02/28/2013] [Indexed: 01/18/2023]
Abstract
It is believed that orthopedic and implant longevity can be improved by optimizing fixation, or direct bone-implant contact, through the stimulation of new bone formation around the implant. The purpose of this study was to determine whether heat (600°C) or radiofrequency plasma glow discharge (RFGD) pretreatment of Ti6Al4V stimulated calcium-phosphate mineral formation in cultures of attached MC3T3 osteoprogenitor cells with or without a fibronectin coating. Calcium-phosphate mineral was analyzed by flame atomic absorption spectrophotometry, scanning electron microscopy (SEM)/electron dispersive X-ray microanalysis (EDAX) and Fourier transformed infrared spectroscopy (FTIR). RFGD and heat pretreatments produced a general pattern of increased total soluble calcium levels, although the effect of heat pretreatment was greater than that of RFGD. SEM/EDAX showed the presence of calcium-and phosphorus-containing particles on untreated and treated disks that were more numerous on fibronectin-coated disks. These particles were observed earliest (1 week) on RFGD-pretreated surfaces. FTIR analyses showed that the heat pretreatment produced a general pattern of increased levels of apatite mineral at 2-4 weeks; a greater effect was observed for fibronectin-coated disks compared to uncoated disks. The observed findings suggest that heat pretreatment of Ti6Al4V increased the total mass of the mineral formed in MC3T3 osteoprogenitor cell cultures more than RFGD while the latter pretreatment hastened the early deposition of mineral. These findings help to support the hypothesis that the pretreatments enhance the osteoinductive properties of the alloy.
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Affiliation(s)
- Bruce E Rapuano
- Hospital for Special Surgery Affiliated With the Weill Medical College of Cornell University, New York, New York 10021, USA
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9
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Lopa S, Mercuri D, Colombini A, Conti G, Segatti F, Zagra L, Moretti M. Orthopedic bioactive implants: Hydrogel enrichment of macroporous titanium for the delivery of mesenchymal stem cells and strontium. J Biomed Mater Res A 2013; 101:3396-403. [DOI: 10.1002/jbm.a.34649] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 02/04/2013] [Accepted: 02/05/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Silvia Lopa
- Cell and Tissue Engineering LaboratoryGruppo Ospedaliero San Donato FoundationMilanItaly
| | - David Mercuri
- Limacorporate s.p.a.Villanova di San Daniele del FriuliUdineItaly
| | - Alessandra Colombini
- Laboratory of Experimental Biochemistry and Molecular BiologyIRCCS Galeazzi Orthopaedic InstituteMilanItaly
| | - Gennyfer Conti
- Limacorporate s.p.a.Villanova di San Daniele del FriuliUdineItaly
| | | | - Luigi Zagra
- Hip DepartmentIRCCS Galeazzi Orthopaedic InstituteMilanItaly
| | - Matteo Moretti
- Cell and Tissue Engineering LaboratoryIRCCS Galeazzi Orthopaedic InstituteMilanItaly
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10
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Bhat KA, Leo Prakash P, Manoharan N, Lakshmibai A, Sangeetha D. Fabrication of polymethyl methacrylate/polysulfone/nanoceramic composites for orthopedic applications. J Appl Polym Sci 2013. [DOI: 10.1002/app.37581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Abstract
Biointegration refers to the interconnection between a biomedical device and the recipient tissue. In many implant devices, the lack of proper biointegration can cause device failure and potentially serious medical problems. This review summarizes the recent progress in surface chemistry, drug delivery and antifouling methods to improve the biointegration of implants. Much progress has been made as our understanding of biological systems and material properties expands and as new technologies become available. This article addresses methods of enhancing biointegration by means of modifying implant surface chemistry and by drug-delivery approaches.
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12
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Desai ES, Tang MY, Ross AE, Gemeinhart RA. Critical factors affecting cell encapsulation in superporous hydrogels. Biomed Mater 2012; 7:024108. [PMID: 22455976 PMCID: PMC3358450 DOI: 10.1088/1748-6041/7/2/024108] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We recently showed that superporous hydrogel (SPH) scaffolds promote long-term stem cell viability and cell driven mineralization when cells were seeded within the pores of pre-fabricated SPH scaffolds. The possibility of cell encapsulation within the SPH matrix during its fabrication was further explored in this study. The impact of each chemical component used in SPH fabrication and each step of the fabrication process on cell viability was systematically examined. Ammonium persulfate, an initiator, and sodium bicarbonate, the gas-generating compound, were the two components having significant toxicity toward encapsulated cells at the concentrations necessary for SPH fabrication. Cell survival rates were 55.7% ± 19.3% and 88.8% ± 9.4% after 10 min exposure to ammonium persulfate and sodium bicarbonate solutions, respectively. In addition, solution pH change via the addition of sodium bicarbonate had significant toxicity toward encapsulated cells with cell survival of only 50.3% ± 2.5%. Despite toxicity of chemical components and the SPH fabrication method, cells still exhibited significant overall survival rates within SPHs of 81.2% ± 6.8% and 67.0% ± 0.9%, respectively, 48 and 72 h after encapsulation. This method of cell encapsulation holds promise for use in vitro and in vivo as a scaffold material for both hydrogel matrix encapsulation and cell seeding within the pores.
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Affiliation(s)
- Esha S Desai
- Department of Biopharmaceutical Sciences, University of Illinois, 833 South Wood Street (MC 865), Chicago, IL 60612-7231
| | - Mary Y Tang
- Department of Biopharmaceutical Sciences, University of Illinois, 833 South Wood Street (MC 865), Chicago, IL 60612-7231
| | - Amy E Ross
- Department of Bioengineering, University of Illinois, Chicago, IL 60607-7052
| | - Richard A Gemeinhart
- Department of Biopharmaceutical Sciences, University of Illinois, 833 South Wood Street (MC 865), Chicago, IL 60612-7231
- Department of Bioengineering, University of Illinois, Chicago, IL 60607-7052
- Department of Ophthalmology and Visual Science, University of Illinois, Chicago, IL 60612-4319
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13
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Xie C, Lu H, Li W, Chen FM, Zhao YM. The use of calcium phosphate-based biomaterials in implant dentistry. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:853-862. [PMID: 22201031 DOI: 10.1007/s10856-011-4535-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 12/12/2011] [Indexed: 05/31/2023]
Abstract
Since calcium phosphates (CaPs) were first proposed, a wide variety of formulations have been developed and continuously optimized, some of which (e.g. calcium phosphate cements, CPCs) have been successfully commercialized for clinical applications. These CaP-based biomaterials have been shown to be very attractive bone substitutes and efficient drug delivery vehicles across diverse biomedical applications. In this article, CaP biomaterials, principally CPCs, are addressed as alternatives/complements to autogenous bone for grafting in implant dentistry and as coating materials for enhancing the osteoinductivity of titanium implants, highlighting their performance benefits simultaneously as carriers for growth factors and as scaffolds for cell proliferation, differentiation and penetration. Different strategies for employing CaP biomaterials in dental implantology aim to ultimately reach the same goal, namely to enhance the osseointegration process for dental implants in the context of immediate loading and to augment the formation of surrounding bone to guarantee long-term success.
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Affiliation(s)
- Cheng Xie
- Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China
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14
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Perez LM, Lalueza P, Monzon M, Puertolas JA, Arruebo M, Santamaría J. Hollow porous implants filled with mesoporous silica particles as a two-stage antibiotic-eluting device. Int J Pharm 2011; 409:1-8. [PMID: 21335077 DOI: 10.1016/j.ijpharm.2011.02.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 12/18/2022]
Abstract
A new type of implantable drug eluting device is presented, consisting of a bed of mesoporous microparticles packed inside a reservoir with a porous wall. This provides two sets of variables for drug release control that can be tailored independently. The first is related to the microparticles (packing density, size and pore structure) and the second to the reservoir (pore diameter and thickness of the wall, permeation area). In this work the concept is developed into a working model, used to fight bacterial (Staphylococcus aureus) growth by releasing linezolid that had previously been adsorbed on silica microparticles. These particles were placed inside the hollow interior of a porous medical grade stainless steel pin mimicking those used in traumatology and in orthopedic surgery. The mechanical behavior of the porous drug-eluting pin was tested and found satisfactory.
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Affiliation(s)
- Luis Manuel Perez
- Aragon Nanoscience Institute (INA), C/Mariano Esquillor, Edif. I+D, University of Zaragoza, 50018 Zaragoza, Spain
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15
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Zhu B, Bailey SR, Mauli Agrawal C. Engineering calcium deposits on polycaprolactone scaffolds for intravascular applications using primary human osteoblasts. J Tissue Eng Regen Med 2010; 5:324-36. [DOI: 10.1002/term.327] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 04/27/2010] [Indexed: 11/08/2022]
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16
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Mao JJ, Stosich MS, Moioli EK, Lee CH, Fu SY, Bastian B, Eisig SB, Zemnick C, Ascherman J, Wu J, Rohde C, Ahn J. Facial reconstruction by biosurgery: cell transplantation versus cell homing. TISSUE ENGINEERING PART B-REVIEWS 2010; 16:257-62. [PMID: 19891541 DOI: 10.1089/ten.teb.2009.0496] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The face distinguishes one human being from another. When the face is disfigured because of trauma, tumor removal, congenital anomalies, or chronic diseases, the patient has a strong desire for functional and esthetic restoration. Current practice of facial reconstruction using autologous grafts, synthetic fillers, and prostheses is frequently below the surgeon's and patient's expectations. Facial reconstruction is yet to take advantage of recent advances in seemingly unrelated fields of stem cell biology, chemical engineering, biomaterials, and tissue engineering. "Biosurgery," a new concept that we propose, will incorporate novel principles and strategies of bioactive cues, biopolymers, and/or cells to restore facial defects. Small facial defects can likely be reconstructed by cell homing and without cell transplantation. A critical advantage of cell homing is that agilely recruited endogenous cells have the potential to harness the host's innate capacity for regeneration, thus accelerating the rate of regulatory and commercialization processes for product development. Large facial defects, however, may not be restorable without cell delivery per our understanding at this time. New breakthrough in biosurgery will likely originate from integrated strategies of cell biology, cytokine biology, chemical engineering, biomaterials, and tissue engineering. Regardless of cell homing or cell delivery approaches, biosurgery not only will minimize surgical trauma and repetitive procedures, but also produce long-lasting results. At the same time, caution must be exercised against the development of products that lack scientific basis or dogmatic combination of cells, biomaterials, and biomolecules. Together, scientifically derived biosurgery will undoubtedly develop into new technologies that offer increasingly natural reconstruction and/or augmentation of the face.
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Affiliation(s)
- Jeremy J Mao
- Tissue Engineering and Regenerative Medicine Laboratory, Columbia University Medical Center, Columbia University, New York, New York 10032, USA
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17
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Abstract
The profession of orthodontics is projected to face a multitude of challenges. Do cyclic forces accelerate the rate of tooth movement and hence the speed of orthodontic treatment? Would bioengineered cementum and dentine be a solution to root resorption? What would orthodontics be like when bioengineered periodontal ligament and alveolar bone become clinical practice, or one day, entire teeth are bioengineered? Would it be possible to selectively differentiate stem cells into osteoblasts or osteoclasts by either static or cyclic forces? What is the new demand on orthodontic expertise with increasingly automated appliances? What will be the impact of the next generation of dental implants or rapid prototyped crowns on orthodontics? A century ago, Edward Angle's practice of fixed appliances, along with other seminal contributions, such as functional appliances, established the profession of orthodontics. Today, the biophysical principles of orthodontics remain largely unchanged from Angle's era, despite incremental refinements of brackets and wires. The paucity of fundamental innovations in orthodontics for decades presents intrinsic risks for the profession. This review will identify challenges for contemporary orthodontics and delineate strategies for the profession to evolve in an era of unprecedented scientific and technological advances, and serve as a call to action for the orthodontic profession.
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Affiliation(s)
- Jeremy J Mao
- Professor, College of Dental Medicine, Division of Orthodontics, Columbia University
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18
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Erdemli O, Captug O, Bilgili H, Orhan D, Tezcaner A, Keskin D. In vitro and in vivo evaluation of the effects of demineralized bone matrix or calcium sulfate addition to polycaprolactone-bioglass composites. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:295-308. [PMID: 19756968 DOI: 10.1007/s10856-009-3862-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 08/22/2009] [Indexed: 05/28/2023]
Abstract
The objective of this study was to improve the efficacy of polycaprolactone/bioglass (PCL/BG) bone substitute using demineralized bone matrix (DBM) or calcium sulfate (CS) as a third component. Composite discs involving either DBM or CS were prepared by compression moulding. Bioactivity of discs was evaluated by energy dispersive X-ray spectroscopy (ESCA) and scanning electron microscopy (SEM) following simulated body fluid incubation. The closest Calcium/Phosphate ratio to that of hydroxyl carbonate apatite crystals was observed for PCL/ BG/DBM group (1.53) after 15 day incubation. Addition of fillers increased microhardness and compressive modulus of discs. However, after 4 and 6-week PBS incubations, PCL/BG/DBM discs showed significant decrease in modulus (from 266.23 to 54.04 and 33.45 MPa, respectively) in parallel with its highest water uptakes (36.3 and 34.7%). Discs preserved their integrity with only considerable weight loss (7.5-14.5%) in PCL/BG/DBM group. In vitro cytotoxicity tests showed that all discs were biocompatible.
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Affiliation(s)
- O Erdemli
- Department of Engineering Sciences, Middle East Technical University, 06531 Ankara, Turkey
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19
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Moioli EK, Clark PA, Chen M, Dennis JE, Erickson HP, Gerson SL, Mao JJ. Synergistic actions of hematopoietic and mesenchymal stem/progenitor cells in vascularizing bioengineered tissues. PLoS One 2008; 3:e3922. [PMID: 19081793 PMCID: PMC2597748 DOI: 10.1371/journal.pone.0003922] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 09/17/2008] [Indexed: 11/19/2022] Open
Abstract
Poor angiogenesis is a major road block for tissue repair. The regeneration of virtually all tissues is limited by angiogenesis, given the diffusion of nutrients, oxygen, and waste products is limited to a few hundred micrometers. We postulated that co-transplantation of hematopoietic and mesenchymal stem/progenitor cells improves angiogenesis of tissue repair and hence the outcome of regeneration. In this study, we tested this hypothesis by using bone as a model whose regeneration is impaired unless it is vascularized. Hematopoietic stem/progenitor cells (HSCs) and mesenchymal stem/progenitor cells (MSCs) were isolated from each of three healthy human bone marrow samples and reconstituted in a porous scaffold. MSCs were seeded in micropores of 3D calcium phosphate (CP) scaffolds, followed by infusion of gel-suspended CD34(+) hematopoietic cells. Co-transplantation of CD34(+) HSCs and CD34(-) MSCs in microporous CP scaffolds subcutaneously in the dorsum of immunocompromised mice yielded vascularized tissue. The average vascular number of co-transplanted CD34(+) and MSC scaffolds was substantially greater than MSC transplantation alone. Human osteocalcin was expressed in the micropores of CP scaffolds and was significantly increased upon co-transplantation of MSCs and CD34(+) cells. Human nuclear staining revealed the engraftment of transplanted human cells in vascular endothelium upon co-transplantation of MSCs and CD34(+) cells. Based on additional in vitro results of endothelial differentiation of CD34(+) cells by vascular endothelial growth factor (VEGF), we adsorbed VEGF with co-transplanted CD34(+) and MSCs in the microporous CP scaffolds in vivo, and discovered that vascular number and diameter further increased, likely owing to the promotion of endothelial differentiation of CD34(+) cells by VEGF. Together, co-transplantation of hematopoietic and mesenchymal stem/progenitor cells may improve the regeneration of vascular dependent tissues such as bone, adipose, muscle and dermal grafts, and may have implications in the regeneration of internal organs.
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Affiliation(s)
- Eduardo K. Moioli
- Columbia University Medical Center, Tissue Engineering and Regenerative Medicine Laboratory (TERML), College of Dental Medicine, New York, New York, United States of America
| | - Paul A. Clark
- Department of Neurological Surgery CSC, University of Wisconsin at Madison Hospital, Madison, Wisconsin, United States of America
| | - Mo Chen
- Columbia University Medical Center, Tissue Engineering and Regenerative Medicine Laboratory (TERML), College of Dental Medicine, New York, New York, United States of America
| | - James E. Dennis
- Department of Orthopaedics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Helaman P. Erickson
- Columbia University Medical Center, Tissue Engineering and Regenerative Medicine Laboratory (TERML), College of Dental Medicine, New York, New York, United States of America
| | - Stanton L. Gerson
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Jeremy J. Mao
- Columbia University Medical Center, Tissue Engineering and Regenerative Medicine Laboratory (TERML), College of Dental Medicine, New York, New York, United States of America
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