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Bektas C, Mao Y. Hydrogel Microparticles for Bone Regeneration. Gels 2023; 10:28. [PMID: 38247752 PMCID: PMC10815488 DOI: 10.3390/gels10010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/19/2023] [Accepted: 12/26/2023] [Indexed: 01/23/2024] Open
Abstract
Hydrogel microparticles (HMPs) stand out as promising entities in the realm of bone tissue regeneration, primarily due to their versatile capabilities in delivering cells and bioactive molecules/drugs. Their significance is underscored by distinct attributes such as injectability, biodegradability, high porosity, and mechanical tunability. These characteristics play a pivotal role in fostering vasculature formation, facilitating mineral deposition, and contributing to the overall regeneration of bone tissue. Fabricated through diverse techniques (batch emulsion, microfluidics, lithography, and electrohydrodynamic spraying), HMPs exhibit multifunctionality, serving as vehicles for drug and cell delivery, providing structural scaffolding, and functioning as bioinks for advanced 3D-printing applications. Distinguishing themselves from other scaffolds like bulk hydrogels, cryogels, foams, meshes, and fibers, HMPs provide a higher surface-area-to-volume ratio, promoting improved interactions with the surrounding tissues and facilitating the efficient delivery of cells and bioactive molecules. Notably, their minimally invasive injectability and modular properties, offering various designs and configurations, contribute to their attractiveness for biomedical applications. This comprehensive review aims to delve into the progressive advancements in HMPs, specifically for bone regeneration. The exploration encompasses synthesis and functionalization techniques, providing an understanding of their diverse applications, as documented in the existing literature. The overarching goal is to shed light on the advantages and potential of HMPs within the field of engineering bone tissue.
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Affiliation(s)
| | - Yong Mao
- Laboratory for Biomaterials Research, Department of Chemistry and Chemical Biology, Rutgers University, 145 Bevier Rd., Piscataway, NJ 08854, USA;
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2
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Rivera KO, Cuylear DL, Duke VR, O’Hara KM, Zhong JX, Elghazali NA, Finbloom JA, Kharbikar BN, Kryger AN, Miclau T, Marcucio RS, Bahney CS, Desai TA. Encapsulation of β-NGF in injectable microrods for localized delivery accelerates endochondral fracture repair. Front Bioeng Biotechnol 2023; 11:1190371. [PMID: 37284244 PMCID: PMC10241161 DOI: 10.3389/fbioe.2023.1190371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/02/2023] [Indexed: 06/08/2023] Open
Abstract
Introduction: Currently, there are no non-surgical FDA-approved biological approaches to accelerate fracture repair. Injectable therapies designed to stimulate bone healing represent an exciting alternative to surgically implanted biologics, however, the translation of effective osteoinductive therapies remains challenging due to the need for safe and effective drug delivery. Hydrogel-based microparticle platforms may be a clinically relevant solution to create controlled and localized drug delivery to treat bone fractures. Here, we describe poly (ethylene glycol) dimethacrylate (PEGDMA)-based microparticles, in the shape of microrods, loaded with beta nerve growth factor (β-NGF) for the purpose of promoting fracture repair. Methods: Herein, PEGDMA microrods were fabricated through photolithography. PEGDMA microrods were loaded with β-NGF and in vitro release was examined. Subsequently, bioactivity assays were evaluated in vitro using the TF-1 tyrosine receptor kinase A (Trk-A) expressing cell line. Finally, in vivo studies using our well-established murine tibia fracture model were performed and a single injection of the β-NGF loaded PEGDMA microrods, non-loaded PEGDMA microrods, or soluble β-NGF was administered to assess the extent of fracture healing using Micro-computed tomography (µCT) and histomorphometry. Results: In vitro release studies showed there is significant retention of protein within the polymer matrix over 168 hours through physiochemical interactions. Bioactivity of protein post-loading was confirmed with the TF-1 cell line. In vivo studies using our murine tibia fracture model show that PEGDMA microrods injected at the site of fracture remained adjacent to the callus for over 7 days. Importantly, a single injection of β-NGF loaded PEGDMA microrods resulted in improved fracture healing as indicated by a significant increase in the percent bone in the fracture callus, trabecular connective density, and bone mineral density relative to soluble β-NGF control indicating improved drug retention within the tissue. The concomitant decrease in cartilage fraction supports our prior work showing that β-NGF promotes endochondral conversion of cartilage to bone to accelerate healing. Discussion: We demonstrate a novel and translational method wherein β-NGF can be encapsulated within PEGDMA microrods for local delivery and that β-NGF bioactivity is maintained resulting in improved bone fracture repair.
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Affiliation(s)
- Kevin O. Rivera
- Graduate Program in Oral and Craniofacial Sciences, School of Dentistry, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Darnell L. Cuylear
- Graduate Program in Oral and Craniofacial Sciences, School of Dentistry, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Victoria R. Duke
- Center for Regenerative and Personalized Medicine, The Steadman Philippon Research Institute (SPRI), Vail, CO, United States
| | - Kelsey M. O’Hara
- Center for Regenerative and Personalized Medicine, The Steadman Philippon Research Institute (SPRI), Vail, CO, United States
| | - Justin X. Zhong
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
- UC Berkeley—UCSF Graduate Program in Bioengineering, San Francisco, CA, United States
| | - Nafisa A. Elghazali
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
- UC Berkeley—UCSF Graduate Program in Bioengineering, San Francisco, CA, United States
| | - Joel A. Finbloom
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Bhushan N. Kharbikar
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Alex N. Kryger
- School of Dentistry, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Theodore Miclau
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Ralph S. Marcucio
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, University of California, San Francisco (UCSF), San Francisco, CA, United States
| | - Chelsea S. Bahney
- Graduate Program in Oral and Craniofacial Sciences, School of Dentistry, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Center for Regenerative and Personalized Medicine, The Steadman Philippon Research Institute (SPRI), Vail, CO, United States
- UC Berkeley—UCSF Graduate Program in Bioengineering, San Francisco, CA, United States
| | - Tejal A. Desai
- Graduate Program in Oral and Craniofacial Sciences, School of Dentistry, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), San Francisco, CA, United States
- Department of Bioengineering, University of California, Berkeley (UC Berkeley), Berkeley, CA, United States
- School of Engineering, Brown University, Providence, RI, United States
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Attias Cohen S, Simaan-Yameen H, Fuoco C, Gargioli C, Seliktar D. Injectable hydrogel microspheres for sustained gene delivery of antisense oligonucleotides to restore the expression of dystrophin protein in duchenne muscular dystrophy. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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4
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Future Drug Targets in Periodontal Personalised Medicine—A Narrative Review. J Pers Med 2022; 12:jpm12030371. [PMID: 35330371 PMCID: PMC8955099 DOI: 10.3390/jpm12030371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/26/2022] [Indexed: 02/08/2023] Open
Abstract
Periodontal disease is an infection-driven inflammatory disease characterized by the destruction of tooth-supporting tissues. The establishment of chronic inflammation will result in progressive destruction of bone and soft tissue changes. Severe periodontitis can lead to tooth loss. The disease has complex pathogenesis with an interplay between genetic, environmental, and host factors and pathogens. Effective management consists of plaque control and non-surgical interventions, along with adjuvant strategies to control inflammation and disrupt the pathogenic subgingival biofilms. Recent studies have examined novel approaches for managing periodontal diseases such as modulating microbial signaling mechanisms, tissue engineering, and molecular targeting of host inflammatory substances. Mounting evidence suggests the need to integrate omics-based approaches with traditional therapy to address the disease. This article discusses the various evolving and future drug targets, including proteomics, gene therapeutics, vaccines, and nanotechnology in personalized periodontal medicine for the effective management of periodontal diseases.
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Yan X, Yang B, Chen Y, Song Y, Ye J, Pan Y, Zhou B, Wang Y, Mao F, Dong Y, Liu D, Yu J. Anti-Friction MSCs Delivery System Improves the Therapy for Severe Osteoarthritis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104758. [PMID: 34657320 DOI: 10.1002/adma.202104758] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Osteoarthritis (OA) is a musculoskeletal disorder disease affecting about 500 million people worldwide and mesenchymal sem cells (MSCs) therapy has been demonstrated as a potential strategy to treat OA. However, the shear forces during direct injection and the harsher shear condition of OA environments would lead to significant cell damage and inhibit the therapeutic efficacy. Herein, DNA supramolecular hydrogel has been applied as delivering material for MSCs to treat severe OA model, which perform extraordinary protection in MSCs against the shear force both in vitro and in vivo. It is demonstrated that the DNA supramolecular hydrogel can promote formation of quality cartilage, reduce osteophyte, and normalize subchondral bone under the high friction condition of OA, whose molecular mechanisms underlying therapeutic effects are also investigated. It can be anticipated that DNA supramolecular hydrogel would be a promising cell delivery system for multiple potential MSCs therapy.
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Affiliation(s)
- Xin Yan
- Department of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, 100191, China
- Institute of Sports Medicine, Peking University, Beijing, 100191, China
| | - Bo Yang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yourong Chen
- Department of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, 100191, China
- Institute of Sports Medicine, Peking University, Beijing, 100191, China
| | - Yifan Song
- Department of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, 100191, China
- Institute of Sports Medicine, Peking University, Beijing, 100191, China
| | - Jing Ye
- Department of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, 100191, China
- Institute of Sports Medicine, Peking University, Beijing, 100191, China
| | - Yufan Pan
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Bini Zhou
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yuqing Wang
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing, 100084, China
| | - Fengbiao Mao
- Institute of Medical Innovation and Research, Peking University Third Hospital, Beijing, 100191, China
| | - Yuanchen Dong
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Dongsheng Liu
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Jiakuo Yu
- Department of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, 100191, China
- Institute of Sports Medicine, Peking University, Beijing, 100191, China
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Evaluation of Microfluidic Approaches to Encapsulate Cells into PEGDA Microparticles. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2021. [DOI: 10.1007/s40883-021-00232-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Abstract
Purpose
Polyethylene glycol diacrylate (PEGDA) is increasingly used to microencapsulate cells via a vortex-induced water-in-oil emulsion process. Herein, we evaluated methods to encapsulate cells into microparticles using microfluidic methods.
Methods
PEGDA prepolymer solution with or without cells was photopolymerized with white light under varying microfluidic parameters to form empty microspheres or cell-laden microparticles. Microparticles and entrapped cells were assessed for size and viability.
Results
PEGDA microparticles were easily formed when cells were absent; the introduction of cells resulted in aggregation that clogged microfluidic devices, resulting in a mix of empty polymer microparticles and cells that were not encapsulated. Cells that were successfully encapsulated had poor viability.
Conclusion
Microfluidic methods may work for low density microencapsulation of mammalian cells; however, when the cell density within each microparticle must be relatively high, emulsion-based methods are superior to microfluidic methods.
Lay Summary
The synthetic polymer polyethylene glycol diacrylate (PEGDA) has been increasingly used to encapsulate cells into micrometer-sized hydrogel spheres (microspheres). One method to microencapsulate cells has been to form a water-in-oil emulsion with liquid polymer containing cells and then expose the suspended droplets to white light, polymerizing them into PEGDA hydrogel microspheres. Although successful, this method has poor control over the process, resulting in polydisperse microsphere sizes with varying cell density. We evaluated microfluidic methods to form both empty and cell-laden PEGDA microspheres. Although microfluidic methods resulted in monodisperse microsphere sizes, the introduction of cells resulted in clogging of microfluidic devices, non-spherical microparticles, and poor cell viability.
Future Work
Because the microfluidic approach successfully formed cell-free microspheres, the effect of reducing cell aggregation will be examined. Specifically, the use of anti-aggregation agents as well as a reduced cell density in the liquid polymer phase and their effects on polymer formation will be explored.
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Hamilton M, Harrington S, Dhar P, Stehno-Bittel L. Hyaluronic Acid Hydrogel Microspheres for Slow Release Stem Cell Delivery. ACS Biomater Sci Eng 2021; 7:3754-3763. [PMID: 34323078 DOI: 10.1021/acsbiomaterials.1c00658] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cell therapies are hampered by a lack of available delivery systems, resulting in inconsistent outcomes in animal studies and human clinical trials. Hydrogel encapsulants offer a broad range of tunable characteristics in the design of cell delivery vehicles. The focus of the hydrogel field has been on durable encapsulants that provide long-term paracrine function of the cells. However, some cell therapies require cell-to-cell contact in order to elicit their effect. Controlled release microencapsulants would be beneficial in these situations, but appropriate polymers have not been adaptable to microsphere manufacturing because they harden too slowly. We developed and tested a novel microencapsulant formulation (acrylated hyaluronic acid: AHA) with degradation characteristics as a controlled release cell delivery vehicle. The properties of AHA microspheres were evaluated and compared to those of poly(ethylene glycol) diacrylate (PEGDA), a durable hydrogel. AHA microspheres possessed a higher swelling ratio, lower diffusion barrier, faster degradation rate, a lower storage modulus, and a larger average diameter than microspheres composed of PEGDA. Additionally, in vitro cell viability and release and short-term in vivo biocompatibility in immune competent Sprague-Dawley rats was assessed for each microsphere type. Compared to PEGDA, microspheres composed of AHA resulted in significantly less foreign body response in vivo as measured by a lack of cellularity or fibrotic ring in the surrounding tissue and no cellular infiltration into the microsphere. This study illustrates the potential of AHA microspheres as a degradable cell delivery system with superior encapsulated cell viability and biocompatibility with the surrounding tissue.
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Affiliation(s)
- Megan Hamilton
- University of Kansas Bioengineering Program, 1132 Learned Hall, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Stephen Harrington
- Likarda LLC, 10330 Hickman Mills Drive, Suite B, Kansas City, Missouri 64137, United States
| | - Prajnaparamita Dhar
- University of Kansas Bioengineering Program, 1132 Learned Hall, 1530 West 15th Street, Lawrence, Kansas 66045, United States.,Department of Chemical and Petroleum Engineering, The University of Kansas, 4132 Learned Hall, 1530 West 15th Street, Lawrence, Kansas 66045, United States
| | - Lisa Stehno-Bittel
- Likarda LLC, 10330 Hickman Mills Drive, Suite B, Kansas City, Missouri 64137, United States
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8
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Biomaterials for human space exploration: A review of their untapped potential. Acta Biomater 2021; 128:77-99. [PMID: 33962071 DOI: 10.1016/j.actbio.2021.04.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/01/2021] [Accepted: 04/15/2021] [Indexed: 02/08/2023]
Abstract
As biomaterial advances make headway into lightweight radiation protection, wound healing dressings, and microbe resistant surfaces, a relevance to human space exploration manifests itself. To address the needs of the human in space, a knowledge of the space environment becomes necessary. Both an understanding of the environment itself and an understanding of the physiological adaptations to that environment must inform design parameters. The space environment permits the fabrication of novel biomaterials that cannot be produced on Earth, but benefit Earth. Similarly, designing a biomaterial to address a space-based challenge may lead to novel biomaterials that will ultimately benefit Earth. This review describes several persistent challenges to human space exploration, a variety of biomaterials that might mitigate those challenges, and considers a special category of space biomaterial. STATEMENT OF SIGNIFICANCE: This work is a review of the major human and environmental challenges facing human spaceflight, and where biomaterials may mitigate some of those challenges. The work is significant because a broad range of biomaterials are applicable to the human space program, but the overlap is not widely known amongst biomaterials researchers who are unfamiliar with the challenges to human spaceflight. Additionaly, there are adaptations to microgravity that mimic the pathology of certain disease states ("terrestrial analogs") where treatments that help the overwhelmingly healthy astronauts can be applied to help those with the desease. Advances in space technology have furthered the technology in that field on Earth. By outlining ways that biomaterials can promote human space exploration, space-driven advances in biomaterials will further biomaterials technology.
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Lopez-Mendez TB, Santos-Vizcaino E, Pedraz JL, Orive G, Hernandez RM. Cell microencapsulation technologies for sustained drug delivery: Latest advances in efficacy and biosafety. J Control Release 2021; 335:619-636. [PMID: 34116135 DOI: 10.1016/j.jconrel.2021.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 10/21/2022]
Abstract
The development of cell microencapsulation systems began several decades ago. However, today few systems have been tested in clinical trials. For this reason, in the last years, researchers have directed efforts towards trying to solve some of the key aspects that still limit efficacy and biosafety, the two major criteria that must be satisfied to reach the clinical practice. Regarding the efficacy, which is closely related to biocompatibility, substantial improvements have been made, such as the purification or chemical modification of the alginates that normally form the microspheres. Each of the components that make up the microcapsules has been carefully selected to avoid toxicities that can damage the encapsulated cells or generate an immune response leading to pericapsular fibrosis. As for the biosafety, researchers have developed biological circuits capable of actively responding to the needs of the patients to precisely and accurately release the demanded drug dose. Furthermore, the structure of the devices has been subject of study to adequately protect the encapsulated cells and prevent their spread in the body. The objective of this review is to describe the latest advances made by scientist to improve the efficacy and biosafety of cell microencapsulation systems for sustained drug delivery, also highlighting those points that still need to be optimized.
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Affiliation(s)
- Tania B Lopez-Mendez
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Edorta Santos-Vizcaino
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain
| | - Jose Luis Pedraz
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain
| | - Gorka Orive
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain; University Institute for Regenerative Medicine and Oral Implantology - UIRMI (UPV/EHU-Fundación Eduardo Anitua), BTI Biotechnology Institute, Vitoria-Gasteiz, Spain; Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Singapore.
| | - Rosa Maria Hernandez
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Salud Carlos III, C/Monforte de Lemos 3-5, 28029 Madrid, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain.
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Um E, Cho YK, Jeong J. Spontaneous Wrinkle Formation on Hydrogel Surfaces Using Photoinitiator Diffusion from Oil-Water Interface. ACS APPLIED MATERIALS & INTERFACES 2021; 13:15837-15846. [PMID: 33689266 DOI: 10.1021/acsami.1c00449] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Patterning wrinkles on three-dimensional curved or enclosed surfaces can be challenging due to difficulties in application of uniform films and stresses on such structures. In this study, we demonstrate a simple one-step wrinkle-formation method on various hydrogel structures utilizing the oil-water interfaces. By diffusion of the photoinitiator from the oil phase to the prepolymer solution in water through the interface, a characteristic cross-linking gradient is set up in the hydrogel. Then, after photopolymerization, we observe diverse patterns of wrinkles upon changing the concentration of the hydrogel or photoinitiator. As the wrinkle formation via photoinitiator diffusion through the interface requires only UV exposure for polymerization, while taking advantage of the oil-water interfacial tension, wrinkles can be developed easily on various curved structures. In addition, we illustrate the formation of wrinkles on surfaces underneath another layer of polymer or on completely enclosed surfaces, which is difficult with conventional methods. We expect that our results will lead to production of novel microstructures and provide a platform for studying the morphogenesis of wrinkles found in nature such as in curved substrates and multilayers.
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Affiliation(s)
- Eujin Um
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Yoon-Kyoung Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Joonwoo Jeong
- Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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11
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White KA, Cali VJ, Olabisi RM. Micropatterning biomineralization with immobilized mother of pearl proteins. Sci Rep 2021; 11:2141. [PMID: 33495508 PMCID: PMC7835238 DOI: 10.1038/s41598-021-81534-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/04/2021] [Indexed: 11/09/2022] Open
Abstract
In response to the drawbacks of autograft donor-site morbidity and bone morphogenetic protein type 2 (BMP2) carcinogenesis and ectopic bone formation, there has been an increased research focus towards developing alternatives capable of achieving spatial control over bone formation. Here we show for the first time both osteogenic differentiation and mineralization (from solution or mediated by cells) occurring within predetermined microscopic patterns. Our results revealed that both PEGylated BMP2 and nacre proteins induced stem cell osteodifferentiation in microscopic patterns when these proteins were covalently bonded in patterns onto polyethylene glycol diacrylate (PEGDA) hydrogel substrates; however, only nacre proteins induced mineralization localized to the micropatterns. These findings have broad implications on the design and development of orthopedic biomaterials and drug delivery.
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Affiliation(s)
- Kristopher A White
- Department of Biomedical Engineering, University of California-Irvine, Irvine, CA, USA
| | - Vincent J Cali
- Department of Anatomy and Physiology, Queens College, City University of New York, Bayside, NY, USA
| | - Ronke M Olabisi
- Department of Biomedical Engineering, University of California-Irvine, Irvine, CA, USA.
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12
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Kupikowska-Stobba B, Lewińska D. Polymer microcapsules and microbeads as cell carriers for in vivo biomedical applications. Biomater Sci 2020; 8:1536-1574. [PMID: 32110789 DOI: 10.1039/c9bm01337g] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Polymer microcarriers are being extensively explored as cell delivery vehicles in cell-based therapies and hybrid tissue and organ engineering. Spherical microcarriers are of particular interest due to easy fabrication and injectability. They include microbeads, composed of a porous matrix, and microcapsules, where matrix core is additionally covered with a semipermeable membrane. Microcarriers provide cell containment at implantation site and protect the cells from host immunoresponse, degradation and shear stress. Immobilized cells may be genetically altered to release a specific therapeutic product directly at the target site, eliminating side effects of systemic therapies. Cell microcarriers need to fulfil a number of extremely high standards regarding their biocompatibility, cytocompatibility, immunoisolating capacity, transport, mechanical and chemical properties. To obtain cell microcarriers of specified parameters, a wide variety of polymers, both natural and synthetic, and immobilization methods can be applied. Yet so far, only a few approaches based on cell-laden microcarriers have reached clinical trials. The main issue that still impedes progress of these systems towards clinical application is limited cell survival in vivo. Herein, we review polymer biomaterials and methods used for fabrication of cell microcarriers for in vivo biomedical applications. We describe their key limitations and modifications aiming at improvement of microcarrier in vivo performance. We also present the main applications of polymer cell microcarriers in regenerative medicine, pancreatic islet and hepatocyte transplantation and in the treatment of cancer. Lastly, we outline the main challenges in cell microimmobilization for biomedical purposes, the strategies to overcome these issues and potential future improvements in this area.
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Affiliation(s)
- Barbara Kupikowska-Stobba
- Laboratory of Electrostatic Methods of Bioencapsulation, Department of Biomaterials and Biotechnological Systems, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland.
| | - Dorota Lewińska
- Laboratory of Electrostatic Methods of Bioencapsulation, Department of Biomaterials and Biotechnological Systems, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland.
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13
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Liang R, Gu Y, Wu Y, Bunpetch V, Zhang S. Lithography-Based 3D Bioprinting and Bioinks for Bone Repair and Regeneration. ACS Biomater Sci Eng 2020; 7:806-816. [PMID: 33715367 DOI: 10.1021/acsbiomaterials.9b01818] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The fabrication of scaffolds that precisely mimic the natural structure and physiochemical properties of bone is still one of the most challenging tasks in bone tissue engineering. 3D printing techniques have drawn increasing attention due to their ability to fabricate scaffolds with complex structures and multiple bioinks. For bone tissue engineering, lithography-based 3D bioprinting is frequently utilized due to its printing speed, mild printing process, and cost-effective benefits. In this review, lithography-based 3D bioprinting technologies including SLA and DLP are introduced; their typical applications in biological system and bioinks are also explored and summarized. Furthermore, we discussed possible evolution of the hardware/software systems and bioinks of lithography-based 3D bioprinting, as well as their future applications.
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Affiliation(s)
- Renjie Liang
- School of Basic Medical Sciences, and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yuqing Gu
- School of Basic Medical Sciences, and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yicong Wu
- School of Basic Medical Sciences, and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Varitsara Bunpetch
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Shufang Zhang
- School of Basic Medical Sciences, and Department of Orthopedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Key Laboratory of Tissue Engineering and Regenerative Medicine of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China.,China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou, 310058, China
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14
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Veronesi F, Maglio M, Brogini S, Fini M. In vivo studies on osteoinduction: A systematic review on animal models, implant site, and type and postimplantation investigation. J Biomed Mater Res A 2020; 108:1834-1866. [PMID: 32297695 DOI: 10.1002/jbm.a.36949] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 03/15/2020] [Accepted: 03/28/2020] [Indexed: 11/10/2022]
Abstract
Musculoskeletal diseases involving loss of tissue usually require management with bone grafts, among which autografts are still the gold standard. To overcome autograft disadvantages, the development of new scaffolds is constantly increasing, as well as the number of in vivo studies evaluating their osteoinductivity in ectopic sites. The aim of the present systematic review is to evaluate the last 10 years of osteoinduction in vivo studies. The review is focused on: (a) which type of animal model is most suitable for osteoinduction evaluation; (b) what are the most used types of scaffolds; (c) what kind of post-explant evaluation is most used. Through three websites (www.pubmed.com, www.webofknowledge.com and www.embase.com), 77 in vivo studies were included. Fifty-eight studies were conducted in small animal models (rodents) and 19 in animals of medium or large size (rabbits, dogs, goats, sheep, and minipigs). Despite the difficulty in establishing the most suitable animal model for osteoinductivity studies, small animals (in particular mice) are the most utilized. Intramuscular implantation is more frequent than subcutis, especially in large animals, and synthetic scaffolds (especially CaP ceramics) are preferred than natural ones, also in combination with cells and growth factors. Paraffin histology and histomorphometric evaluations are usually employed for postimplantation analyses.
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Affiliation(s)
- Francesca Veronesi
- IRCCS-Istituto Ortopedico Rizzoli, Laboratory of Preclinical and Surgical Studies, Bologna, Italy
| | - Melania Maglio
- IRCCS-Istituto Ortopedico Rizzoli, Laboratory of Preclinical and Surgical Studies, Bologna, Italy
| | - Silvia Brogini
- IRCCS-Istituto Ortopedico Rizzoli, Laboratory of Preclinical and Surgical Studies, Bologna, Italy
| | - Milena Fini
- IRCCS-Istituto Ortopedico Rizzoli, Laboratory of Preclinical and Surgical Studies, Bologna, Italy
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15
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Chang S, Finklea F, Williams B, Hammons H, Hodge A, Scott S, Lipke E. Emulsion-based encapsulation of pluripotent stem cells in hydrogel microspheres for cardiac differentiation. Biotechnol Prog 2020; 36:e2986. [PMID: 32108999 DOI: 10.1002/btpr.2986] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/12/2020] [Accepted: 02/24/2020] [Indexed: 12/11/2022]
Abstract
Cardiovascular disease is the leading cause of death worldwide, and current treatments are ineffective or unavailable to majority of patients. Engineered cardiac tissue (ECT) is a promising treatment to restore function to the damaged myocardium; however, for these treatments to become a reality, tissue fabrication must be amenable to scalable production and be used in suspension culture. Here, we have developed a low-cost and scalable emulsion-based method for producing ECT microspheres from poly(ethylene glycol) (PEG)-fibrinogen encapsulated mouse embryonic stem cells (mESCs). Cell-laden microspheres were formed via water-in-oil emulsification; encapsulation occurred by suspending the cells in hydrogel precursor solution at cell densities from 5 to 60 million cells/ml, adding to mineral oil and vortexing. Microsphere diameters ranged from 30 to 570 μm; size variability was decreased by the addition of 2% poly(ethylene glycol) diacrylate. Initial cell encapsulation density impacted the ability for mESCs to grow and differentiate, with the greatest success occurring at higher cell densities. Microspheres differentiated into dense spheroidal ECTs with spontaneous contractions occurring as early as Day 10 of cardiac differentiation; furthermore, these ECT microspheres exhibited appropriate temporal changes in gene expression and response to pharmacological stimuli. These results demonstrate the ability to use an emulsion approach to encapsulate pluripotent stem cells for use in microsphere-based cardiac differentiation.
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Affiliation(s)
- Samuel Chang
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Ferdous Finklea
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Bianca Williams
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Hanna Hammons
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Alexander Hodge
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Samantha Scott
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
| | - Elizabeth Lipke
- Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, Alabama, USA
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16
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Santos-Vizcaino E, Orive G, Pedraz JL, Hernandez RM. Clinical Applications of Cell Encapsulation Technology. Methods Mol Biol 2020; 2100:473-491. [PMID: 31939144 DOI: 10.1007/978-1-0716-0215-7_32] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cell encapsulation comprises immunoisolation three-dimensional systems for housing therapeutic cells that secrete bioactive compounds de novo and in a sustained manner. This allows transplantation of multiple allo- or xenogeneic cells without the aid of immunosuppressant drugs. Recent advances in the field have provided improvements to these cell-based drug delivery systems, which have gained the attention of the scientific community and inspired many biotechnological companies to develop their own product candidates. From micro- to macroencapsulation devices, this chapter describes some of the most important approaches that are being currently tested in late-stage clinical trials and are likely to reach the market as future game changers. Most studies involve the treatment of diabetes, eye disorders, and diseases of the central nervous system. However, many other pathologies are also amenable to benefit from this technology. Latest advances to overcome major pending challenges related to biosafety and efficacy are also discussed.
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Affiliation(s)
- Edorta Santos-Vizcaino
- NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain.,Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Vitoria-Gasteiz, Spain
| | - Gorka Orive
- NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain.,Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Vitoria-Gasteiz, Spain.,University Institute for Regenerative Medicine and Oral Implantology-UIRMI (UPV/EHU-Fundación Eduardo Anitua), Vitoria, Spain.,BTI Biotechnology Institute, Vitoria, Spain
| | - Jose Luis Pedraz
- NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain.,Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Vitoria-Gasteiz, Spain
| | - Rosa Maria Hernandez
- NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain. .,Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Vitoria-Gasteiz, Spain.
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17
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Oberdick SD, Zabow G. Patterned Surface Energy in Elastomeric Molds as a Generalized Approach to Polymer Particle Fabrication. ACS APPLIED POLYMER MATERIALS 2020; 2:https://doi.org/10.1021/acsapm.9b01109. [PMID: 32864622 PMCID: PMC7450726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a generic fabrication scheme to produce polymer microparticles with engineerable, complex shapes. The polymer particles are made from polyethylene glycol based hydrogels using a poly(dimethylsiloxane) (PDMS) molding technique. A simple surface treatment is used to pattern the surface energy of the PDMS molds, engendering the recessed wells in the molds with a higher surface energy than that of the surface. The contrast in surface energy causes hydrogel precursor to wet only the inside of the molds, creating isolated particles after curing with UV light. This eliminates the formation of an interconnecting "scum" layer and allows for fabrication of well-defined, independent particles. We discuss resolution limits for the approach and present a simple strategy for releasing the particles. Finally, to show how the fabrication technique is inherently compatible with further particle modifications, we also demonstrate magnetic functionalization of particles.
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Affiliation(s)
- Samuel D Oberdick
- National Institute of Standards and Technology, Boulder, Colorado, and University of Colorado, Boulder, Coloradoh
| | - Gary Zabow
- National Institute of Standards and Technology, Boulder, Colorado, and University of Colorado, Boulder, Coloradoh
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18
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White KA, Olabisi RM. Spatiotemporal Control Strategies for Bone Formation through Tissue Engineering and Regenerative Medicine Approaches. Adv Healthc Mater 2019; 8:e1801044. [PMID: 30556328 DOI: 10.1002/adhm.201801044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/06/2018] [Indexed: 02/06/2023]
Abstract
Global increases in life expectancy drive increasing demands for bone regeneration. The gold standard for surgical bone repair is autografting, which enjoys excellent clinical outcomes; however, it possesses significant drawbacks including donor site morbidity and limited availability. Although collagen sponges delivered with bone morphogenetic protein, type 2 (BMP2) are a common alternative or supplement, they do not efficiently retain BMP2, necessitating extremely high doses to elicit bone formation. Hence, reports of BMP2 complications are rising, including cancer promotion and ectopic bone formation, the latter inducing complications such as breathing difficulties and neurologic impairments. Thus, efforts to exert spatial control over bone formation are increasing. Several tissue engineering approaches have demonstrated the potential for targeted and controlled bone formation. These approaches include biomaterial scaffolds derived from synthetic sources, e.g., calcium phosphates or polymers; natural sources, e.g., bone or seashell; and immobilized biofactors, e.g., BMP2. Although BMP2 is the only protein clinically approved for use in a surgical device, there are several proteins, small molecules, and growth factors that show promise in tissue engineering applications. This review profiles the tissue engineering advances in achieving control over the location and onset of bone formation (spatiotemporal control) toward avoiding the complications associated with BMP2.
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Affiliation(s)
- Kristopher A. White
- Department of Chemical and Biochemical Engineering; Rutgers University; 98 Brett Road Piscataway NJ 08854 USA
| | - Ronke M. Olabisi
- Department of Biomedical Engineering; Rutgers University; 599 Taylor Road Piscataway NJ 08854 USA
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19
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Li H, Ma T, Zhang M, Zhu J, Liu J, Tan F. Fabrication of sulphonated poly(ethylene glycol)-diacrylate hydrogel as a bone grafting scaffold. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:187. [PMID: 30535592 DOI: 10.1007/s10856-018-6199-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/27/2018] [Indexed: 06/09/2023]
Abstract
To improve the biological performance of poly(ethylene glycol)-diacrylate (PEGDA) hydrogel as an injectable bone grafting scaffold, sodium methallyl sulphonate (SMAS) was incorporated into PEGDA hydrogel. The physiochemical properties of the resultant polymers were assessed via Fourier transform infrared spectroscopy (FTIR), swelling ratio, zeta potential, surface morphology, and protein adsorption analysis. MC3T3-E1 cells were seeded on the hydrogel to evaluate the effect of the sulphonated modification on their attachment, proliferation, and differentiation. The results of FTIR and zeta potential evaluations revealed that SMAS was successfully incorporated into PEGDA. With increasing concentrations of SMAS, the swelling ratio of the hydrogels increased in deionized water but stayed constant in phosphate buffered saline. The protein adsorption also increased with increasing concentration of SMAS. Moreover, the sulphonated modification of PEGDA hydrogel not only enhanced the attachment and proliferation of osteoblast-like MC3T3-E1 cells but also up-regulated alkaline phosphatase activity as well as gene expression of osteogenic markers and related growth factors, including collagen type I, osteocalcin, runt related transcription factor 2, bone morphogenetic protein 2, and transforming growth factor beta 1. These findings indicate that the sulphonated modification could significantly improve the biological performance of PEGDA hydrogel. Thus, the sulphonated PEGDA is a promising scaffold candidate for bone grafting.
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Affiliation(s)
- Hao Li
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China
| | - Tingting Ma
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China
| | - Man Zhang
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China
| | - Jiani Zhu
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China
| | - Jie Liu
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China
| | - Fei Tan
- Department of Prosthodontics, the Affiliated Hospital of Qingdao University, Qingdao University, 266003, Qingdao, People's Republic of China.
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20
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Perera D, Medini M, Seethamraju D, Falkowski R, White K, Olabisi RM. The effect of polymer molecular weight and cell seeding density on viability of cells entrapped within PEGDA hydrogel microspheres. J Microencapsul 2018; 35:475-481. [DOI: 10.1080/02652048.2018.1526341] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Davina Perera
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Michael Medini
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | | | - Ron Falkowski
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Kristopher White
- Chemical and Biochemical Engineering, Rutgers University, New Brunswick, NJ, USA
| | - Ronke M. Olabisi
- Biomedical Engineering, Rutgers University, New Brunswick, NJ, USA
- Institute of Advanced Materials, Devices and Nanotechnology, Rutgers University, New Brunswick, NJ, USA
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21
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Alvarez-Urena P, Zhu B, Henslee G, Sonnet C, Davis E, Sevick-Muraca E, Davis A, Olmsted-Davis E. Development of a Cell-Based Gene Therapy Approach to Selectively Turn Off Bone Formation. J Cell Biochem 2017. [PMID: 28621436 DOI: 10.1002/jcb.26220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cell and gene therapy approaches are safer when they possess a system that enables the therapy to be rapidly halted. Human mesenchymal stem cells were transduced with an adenoviral vector containing the cDNA for bone morphogenetic protein 2 (AdBMP2) to induce bone formation. To make this method safer, a system to quickly kill these virally transduced cells was designed and evaluated. Cells were encapsulated inside poly(ethylene glycol) diacrylate (PEG-Da) hydrogels that are able to shield the cells from immunological destruction. The system involves an inducible caspase-9 (iCasp9) activated using a specific chemical inducer of dimerization (CID). Delivering AdBMP2-transduced human mesenchymal stem cells encapsulated in PEG-Da hydrogel promoted ectopic ossification in vivo, and the iCasp9 system allowed direct control of the timing of apoptosis of the injected cells. The iCasp9-CID system enhances the safety of delivering AdBMP2-transduced cells, making it a more compelling therapeutic for bone repair and spine fusion. J. Cell. Biochem. 118: 3627-3634, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Pedro Alvarez-Urena
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Banghe Zhu
- Center for Molecular Imaging, University of Texas Health Sciences Center, Houston, Texas.,Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine, Houston, Texas
| | - Gabrielle Henslee
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Corinne Sonnet
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Eleanor Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Eva Sevick-Muraca
- Center for Molecular Imaging, University of Texas Health Sciences Center, Houston, Texas
| | - Alan Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas.,Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine, Houston, Texas.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas
| | - Elizabeth Olmsted-Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas.,Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine, Houston, Texas.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas
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22
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Foster AA, Marquardt LM, Heilshorn SC. The Diverse Roles of Hydrogel Mechanics in Injectable Stem Cell Transplantation. Curr Opin Chem Eng 2017; 15:15-23. [PMID: 29085771 PMCID: PMC5659597 DOI: 10.1016/j.coche.2016.11.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Stem cell delivery by local injection has tremendous potential as a regenerative therapy but has seen limited clinical success. Several mechanical challenges hinder therapeutic efficacy throughout all stages of cell transplantation, including mechanical forces during injection and loss of mechanical support post-injection. Recent studies have begun exploring the use of biomaterials, in particular hydrogels, to enhance stem cell transplantation by addressing the often-conflicting mechanical requirements associated with each stage of the transplantation process. This review explores recent biomaterial approaches to improve the therapeutic efficacy of stem cells delivered through local injection, with a focus on strategies that specifically address the mechanical challenges that result in cell death and/or limit therapeutic function throughout the stages of transplantation.
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Affiliation(s)
- Abbygail A Foster
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
| | - Laura M Marquardt
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
| | - Sarah C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
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23
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Alvarez-Urena P, Davis E, Sonnet C, Henslee G, Gugala Z, Strecker EV, Linscheid LJ, Cuchiara M, West J, Davis A, Olmsted-Davis E. Encapsulation of Adenovirus BMP2-Transduced Cells with PEGDA Hydrogels Allows Bone Formation in the Presence of Immune Response. Tissue Eng Part A 2017; 23:177-184. [PMID: 27967655 DOI: 10.1089/ten.tea.2016.0277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Gene therapy approaches have been difficult to implement due to pre-existing immunity against the virus used for delivery. To circumvent this problem, a cell-based approach was developed that avoided the use of free virus within the animal. However, even cells transduced in vitro with E1- to E3-deleted adenovirus encoding bone morphogenetic protein 2 (AdBMP2) resulted in the production of virus-neutralizing antibodies in mice. Furthermore, when mice received an intramuscular injection of nonencoding adenovirus (AdEmpty)-transduced cells, AdBMP2-transduced cells were unable to launch bone formation when an intramuscular injection of these BMP2-producing cells was delivered 1 week later. This phenomenon was not observed in NOD/SCID mice, and could be overcome in C57BL/6 mice by encapsulating the adenovirus-transduced cells in a nondegradable hydrogel poly(ethylene glycol) diacrylate (PEGDA). Data collectively suggest that PEGDA hydrogel encapsulation of AdBMP2-transduced cells prevents pre-existing immunity from suppressing BMP2-induced bone formation.
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Affiliation(s)
- Pedro Alvarez-Urena
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Eleanor Davis
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Corinne Sonnet
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Gabrielle Henslee
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas
| | - Zbigniew Gugala
- 2 Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch at Galveston , Galveston, Texas
| | - Edward V Strecker
- 2 Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch at Galveston , Galveston, Texas
| | - Laura J Linscheid
- 2 Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch at Galveston , Galveston, Texas
| | - Maude Cuchiara
- 3 Department of Biomedical Engineering, Duke University , Durham, North Carolina
| | - Jennifer West
- 3 Department of Biomedical Engineering, Duke University , Durham, North Carolina
| | - Alan Davis
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas.,4 Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine , Houston, Texas.,5 Department of Orthopedic Surgery, Baylor College of Medicine , Houston, Texas
| | - Elizabeth Olmsted-Davis
- 1 Center for Cell and Gene Therapy , Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas.,4 Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine , Houston, Texas.,5 Department of Orthopedic Surgery, Baylor College of Medicine , Houston, Texas
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24
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Abstract
Mammalian cells have been microencapsulated within both natural and synthetic polymers for over half a century. Specifically, in the last 36 years microencapsulated cells have been used therapeutically to deliver a wide range of drugs, cytokines, growth factors, and hormones while enjoying the immunoisolation provided by the encapsulating material. In addition to preventing immune attack, microencapsulation prevents migration of entrapped cells. Cells can be microencapsulated in a variety of geometries, the most common being solid microspheres and hollow microcapsules. The micrometer scale permits delivery by injection and is within diffusion limits that allow the cells to provide the necessary factors that are missing at a target site, while also permitting the exchange of nutrients and waste products. The majority of cell microencapsulation is performed with alginate/poly-L-lysine microspheres. Since alginate itself can be immunogenic, for cell-based therapy applications various groups are investigating synthetic polymers to microencapsulate cells. We describe a protocol for the formation of microspheres and microcapsules using the synthetic polymer poly(ethylene glycol) diacrylate (PEGDA).
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Affiliation(s)
- A Aijaz
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ, 08854, USA
| | - D Perera
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ, 08854, USA
| | - Ronke M Olabisi
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ, 08854, USA.
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25
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Majewski RL, Zhang W, Ma X, Cui Z, Ren W, Markel DC. Bioencapsulation technologies in tissue engineering. J Appl Biomater Funct Mater 2016; 14:e395-e403. [PMID: 27716872 PMCID: PMC5623183 DOI: 10.5301/jabfm.5000299] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2016] [Indexed: 12/30/2022] Open
Abstract
Bioencapsulation technologies have played an important role in the developing successes of tissue engineering. Besides offering immunoisolation, they also show promise for cell/tissue banking and the directed differentiation of stem cells, by providing a unique microenvironment. This review describes bioencapsulation technologies and summarizes their recent progress in research into tissue engineering. The review concludes with a brief outlook regarding future research directions in this field.
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Affiliation(s)
- Rebecca L. Majewski
- BioMolecular Engineering Program, Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin - USA
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin - USA
| | - Wujie Zhang
- BioMolecular Engineering Program, Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin - USA
| | - Xiaojun Ma
- Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning Province - PR China
| | - Zhanfeng Cui
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford - UK
| | - Weiping Ren
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan - USA
- Department of Orthopedic Surgery, Providence Hospital and Medical Centers, Southfield, Michigan - USA
| | - David C. Markel
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan - USA
- Department of Orthopedic Surgery, Providence Hospital and Medical Centers, Southfield, Michigan - USA
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26
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Davis EL, Sonnet C, Lazard ZW, Henslee G, Gugala Z, Salisbury EA, Strecker EV, Davis TA, Forsberg JA, Davis AR, Olmsted‐Davis EA. Location-dependent heterotopic ossification in the rat model: The role of activated matrix metalloproteinase 9. J Orthop Res 2016; 34:1894-1904. [PMID: 26919547 PMCID: PMC5001934 DOI: 10.1002/jor.23216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/23/2016] [Indexed: 02/04/2023]
Abstract
Extremity amputation or traumatic injury can often lead to the formation of heterotopic ossification (HO). Studies to induce HO in rat muscle using cell-based gene therapy show that this process appears to be location dependent. In the present study, HO was induced in mice and rats through injection of immunologically matched cells transduced with either a replication-defective adenovirus possessing bone morphogenetic protein 2 (BMP2) or an empty adenovirus vector (control). Injection in rat near the skeletal bone resulted in HO, whereas cells injected into the same muscle group but distal from the bone did not result in bone formation. When cells were injected in the same limb at both locations at the same time, HO was formed at both sites. Characterization of the bone formation in rats versus mice demonstrated that different sources of osteogenic progenitors were involved, which may account for the location dependent bone formation observed in the rat. Further experimentation has shown that a potential reason for this difference may be the inability of rat to activate matrix metalloproteinase 9 (MMP9), an essential protease in mice necessary for recruitment of progenitors. Inhibition of active MMP9 in mice led to a significant decrease in HO. The studies reported here provide insight into the mechanisms and pathways leading to bone formation in different animals and species. It appears that not all animal models are appropriate for testing HO therapies, and our studies also challenge the conventional wisdom that larger animal models are better for testing treatments affecting bone. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1894-1904, 2016.
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Affiliation(s)
- Eleanor L. Davis
- Center for Cell and Gene TherapyBaylor College of MedicineHoustonTexas77030
| | - Corinne Sonnet
- Center for Cell and Gene TherapyBaylor College of MedicineHoustonTexas77030,Department of MedicineBaylor College of MedicineHoustonTexas77030
| | | | - Gabrielle Henslee
- Center for Cell and Gene TherapyBaylor College of MedicineHoustonTexas77030
| | - Zbigniew Gugala
- Department of Orthopedic SurgeryUniversity of Texas Medical Branch GalvestonGalvestonTexas77555
| | - Elizabeth A. Salisbury
- Department of Orthopedic SurgeryUniversity of Texas Medical Branch GalvestonGalvestonTexas77555
| | - Edward V. Strecker
- Department of Orthopedic SurgeryUniversity of Texas Medical Branch GalvestonGalvestonTexas77555
| | - Thomas A. Davis
- Department of Regenerative MedicineNaval Medical Research CenterSilver SpringMaryland20910
| | - Jonathan A. Forsberg
- Department of Regenerative MedicineNaval Medical Research CenterSilver SpringMaryland20910
| | - Alan R. Davis
- Center for Cell and Gene TherapyBaylor College of MedicineHoustonTexas77030,Department of PediatricsBaylor College of MedicineHoustonTexas77030,Department of Orthopedic SurgeryBaylor College of MedicineHoustonTexas77030
| | - Elizabeth A. Olmsted‐Davis
- Center for Cell and Gene TherapyBaylor College of MedicineHoustonTexas77030,Department of PediatricsBaylor College of MedicineHoustonTexas77030,Department of Orthopedic SurgeryBaylor College of MedicineHoustonTexas77030
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Krutkramelis K, Xia B, Oakey J. Monodisperse polyethylene glycol diacrylate hydrogel microsphere formation by oxygen-controlled photopolymerization in a microfluidic device. LAB ON A CHIP 2016; 16:1457-65. [PMID: 26987384 PMCID: PMC4829474 DOI: 10.1039/c6lc00254d] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PEG-based hydrogels have become widely used as drug delivery and tissue scaffolding materials. Common among PEG hydrogel-forming polymers are photopolymerizable acrylates such as polyethylene glycol diacrylate (PEGDA). Microfluidics and microfabrication technologies have recently enabled the miniaturization of PEGDA structures, thus enabling many possible applications for nano- and micro- structured hydrogels. The presence of oxygen, however, dramatically inhibits the photopolymerization of PEGDA, which in turn frustrates hydrogel formation in environments of persistently high oxygen concentration. Using PEGDA that has been emulsified in fluorocarbon oil via microfluidic flow focusing within polydimethylsiloxane (PDMS) devices, we show that polymerization is completely inhibited below critical droplet diameters. By developing an integrated model incorporating reaction kinetics and oxygen diffusion, we demonstrate that the critical droplet diameter is largely determined by the oxygen transport rate, which is dictated by the oxygen saturation concentration of the continuous oil phase. To overcome this fundamental limitation, we present a nitrogen micro-jacketed microfluidic device to reduce oxygen within the droplet, enabling the continuous on-chip photopolymerization of microscale PEGDA particles.
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Affiliation(s)
- K Krutkramelis
- Department of Chemical Engineering, University of Wyoming, USA.
| | - B Xia
- Department of Chemical Engineering, University of Wyoming, USA.
| | - J Oakey
- Department of Chemical Engineering, University of Wyoming, USA.
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Pellegrini M, Cherukupalli A, Medini M, Falkowski R, Olabisi R. The Effect of Swelling Ratio on the Coulter Underestimation of Hydrogel Microsphere Diameters. Tissue Eng Part C Methods 2015; 21:1246-50. [PMID: 26414785 PMCID: PMC4663640 DOI: 10.1089/ten.tec.2015.0246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been demonstrated that the diameters of porous particles are underestimated by Coulter measurements. This phenomenon has also been observed in hydrogel particles, but not characterized. Since the Coulter principle uses the displacement of electrolyte to determine particle size, electrolyte contained within the swelled hydrogel microparticles results in an underestimate of actual particle diameters. The increased use of hydrogel microspheres in biomedical applications has led to the increased application of the Coulter principle to evaluate the size distribution of microparticles. A relationship between the swelling ratio of the particles and their reported Coulter diameters will permit calculation of the actual diameters of these particles. Using polyethylene glycol diacrylate hydrogel microspheres, we determined a correction factor that relates the polymer swelling ratio and the reported Coulter diameters to their actual size.
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Affiliation(s)
- Michael Pellegrini
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | | | - Michael Medini
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | - Ron Falkowski
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | - Ronke Olabisi
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
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29
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Chiang CW, Chen WC, Liu HW, Wang IC, Chen CH. Evaluating Osteogenic Potential of Ligamentum Flavum Cells Cultivated in Photoresponsive Hydrogel that Incorporates Bone Morphogenetic Protein-2 for Spinal Fusion. Int J Mol Sci 2015; 16:23318-36. [PMID: 26426006 PMCID: PMC4632700 DOI: 10.3390/ijms161023318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 09/08/2015] [Accepted: 09/22/2015] [Indexed: 12/02/2022] Open
Abstract
Regenerative medicine is increasingly important in clinical practice. Ligamentum flava (LF) are typically removed during spine-related surgeries. LF may be a source of cells for spinal fusion that is conducted using tissue engineering techniques. In this investigation, LF cells of rabbits were isolated and then characterized by flow cytometry, morphological observation, and immunofluorescence staining. The LF cells were also cultivated in polyethylene (glycol) diacrylate (PEGDA) hydrogels that incorporated bone morphogenetic protein-2 (BMP-2) growth factor, to evaluate their proliferation and secretion of ECM and differentiation in vitro. The experimental results thus obtained that the proliferation, ECM secretion, and differentiation of the PEGDA-BMP-2 group exceeded those of the PEGDA group during the period of cultivation. The mineralization and histological staining results differed similarly. A nude mice model was utilized to prove that LF cells on hydrogels could undergo osteogenic differentiation in vivo. These experimental results also revealed that the PEGDA-BMP-2 group had better osteogenic effects than the PEGDA group following a 12 weeks after transplantation. According to all of these experimental results, LF cells are a source of cells for spinal fusion and PEGDA-BMP-2 hydrogel is a candidate biomaterial for spinal fusion by tissue engineering.
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Affiliation(s)
- Chih-Wei Chiang
- Bone and Joint Research Center, Department of Orthopedics and Traumatology, Taipei Medical University Hospital, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan.
| | - Wei-Chuan Chen
- Bone and Joint Research Center, Department of Orthopedics and Traumatology, Taipei Medical University Hospital, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
| | - Hsia-Wei Liu
- Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City 242, Taiwan.
| | - I-Chun Wang
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Keelung 204, Taiwan.
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
| | - Chih-Hwa Chen
- Bone and Joint Research Center, Department of Orthopedics and Traumatology, Taipei Medical University Hospital, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 110, Taiwan.
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30
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Aijaz A, Faulknor R, Berthiaume F, Olabisi RM. Hydrogel Microencapsulated Insulin-Secreting Cells Increase Keratinocyte Migration, Epidermal Thickness, Collagen Fiber Density, and Wound Closure in a Diabetic Mouse Model of Wound Healing. Tissue Eng Part A 2015; 21:2723-32. [PMID: 26239745 PMCID: PMC4652158 DOI: 10.1089/ten.tea.2015.0069] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Wound healing is a hierarchical process of intracellular and intercellular signaling. Insulin is a potent chemoattractant and mitogen for cells involved in wound healing. Insulin's potential to promote keratinocyte growth and stimulate collagen synthesis in fibroblasts is well described. However, there currently lacks an appropriate delivery mechanism capable of consistently supplying a wound environment with insulin; current approaches require repeated applications of insulin, which increase the chances of infecting the wound. In this study, we present a novel cell-based therapy that delivers insulin to the wound area in a constant or glucose-dependent manner by encapsulating insulin-secreting cells in nonimmunogenic poly(ethylene glycol) diacrylate (PEGDA) hydrogel microspheres. We evaluated cell viability and insulin secretory characteristics of microencapsulated cells. Glucose stimulation studies verified free diffusion of glucose and insulin through the microspheres, while no statistical difference in insulin secretion was observed between cells in microspheres and cells in monolayers. Scratch assays demonstrated accelerated keratinocyte migration in vitro when treated with microencapsulated cells. In excisional wounds on the dorsa of diabetic mice, microencapsulated RIN-m cells accelerated wound closure by postoperative day 7; a statistically significant increase over AtT-20ins-treated and control groups. Histological results indicated significantly greater epidermal thickness in both microencapsulated RIN-m and AtT-20ins-treated wounds. The results suggest that microencapsulation enables insulin-secreting cells to persist long enough at the wound site for a therapeutic effect and thereby functions as an effective delivery vehicle to accelerate wound healing.
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Affiliation(s)
- Ayesha Aijaz
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | - Renea Faulknor
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | - François Berthiaume
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
| | - Ronke M Olabisi
- Department of Biomedical Engineering, Rutgers University , Piscataway, New Jersey
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31
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Cell encapsulation: technical and clinical advances. Trends Pharmacol Sci 2015; 36:537-46. [DOI: 10.1016/j.tips.2015.05.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 01/18/2023]
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Olabisi RM. Cell microencapsulation with synthetic polymers. J Biomed Mater Res A 2015; 103:846-59. [PMID: 24771675 PMCID: PMC4309473 DOI: 10.1002/jbm.a.35205] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/11/2014] [Accepted: 04/21/2014] [Indexed: 12/18/2022]
Abstract
The encapsulation of cells into polymeric microspheres or microcapsules has permitted the transplantation of cells into human and animal subjects without the need for immunosuppressants. Cell-based therapies use donor cells to provide sustained release of a therapeutic product, such as insulin, and have shown promise in treating a variety of diseases. Immunoisolation of these cells via microencapsulation is a hotly investigated field, and the preferred material of choice has been alginate, a natural polymer derived from seaweed due to its gelling conditions. Although many natural polymers tend to gel in conditions favorable to mammalian cell encapsulation, there remain challenges such as batch to batch variability and residual components from the original source that can lead to an immune response when implanted into a recipient. Synthetic materials have the potential to avoid these issues; however, historically they have required harsh polymerization conditions that are not favorable to mammalian cells. As research into microencapsulation grows, more investigators are exploring methods to microencapsulate cells into synthetic polymers. This review describes a variety of synthetic polymers used to microencapsulate cells.
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Affiliation(s)
- Ronke M Olabisi
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, New Jersey, 08854
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33
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Secret E, Kelly SJ, Crannell KE, Andrew JS. Enzyme-responsive hydrogel microparticles for pulmonary drug delivery. ACS APPLIED MATERIALS & INTERFACES 2014; 6:10313-21. [PMID: 24926532 DOI: 10.1021/am501754s] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Poly(ethylene glycol) based hydrogel microparticles were developed for pulmonary drug delivery. Hydrogels are particularly attractive for pulmonary delivery because they can be size engineered for delivery into the bronchi, yet also swell upon reaching their destination to avoid uptake and clearance by alveolar macrophages. To develop enzyme-responsive hydrogel microparticles for pulmonary delivery a new synthesis method based on a solution polymerization was developed. This method produces spherical poly(ethylene glycol) (PEG) microparticles from high molecular weight poly(ethylene glycol) diacrylate (PEGDA)-based precursors that incorporate peptides in the polymer chain. Specifically, we have synthesized hydrogel microparticles that degrade in response to matrix metalloproteinases that are overexpressed in pulmonary diseases. Small hydrogel microparticles with sizes suitable for lung delivery by inhalation were obtained from solid precursors when PEGDA was dissolved in water at a high concentration. The average diameter of the particles was between 2.8 and 4 μm, depending on the molecular weight of the precursor polymer used and its concentration in water. The relation between the physical properties of the particles and their enzymatic degradation is also reported, where an increased mesh size corresponds to increased degradation.
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Affiliation(s)
- Emilie Secret
- Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States
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34
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Pradhan S, Chaudhury CS, Lipke EA. Dual-phase, surface tension-based fabrication method for generation of tumor millibeads. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3817-3825. [PMID: 24617794 DOI: 10.1021/la500402m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Numerous methods have been developed for the fabrication of poly(ethylene glycol)-based hydrogel microstructures for drug-delivery and tissue-engineering applications. However, present methods focus on the fabrication of submicrometer scale hydrogel structures which have limited applications in creating larger tissue constructs, especially in recreating cancer tissue microenvironments. We aimed to establish a platform where cancer cells can be cultured in a three-dimensional (3D) environment, which closely replicates the native cancer microenvironment and facilitates efficient testing of anticancer drugs. This study demonstrated a novel surface tension-based fabrication technique for the generation of millimeter-scale hydrogel beads using a liquid-liquid dual phase system. The "hydrogel millibeads" obtained by this method were larger than previously reported, highly uniform in shape and size with better ease of size control and a high degree of consistency and reproducibility between batches. In addition, human breast cancer cells were encapsulated within these hydrogel constructs to generate "tumor millibeads", which were subsequently maintained in long-term 3D culture. Microscopic visualization using fluorescence imaging and microstructure analysis showed the morphology and uniform distribution of the cells within the 3D matrix and arrangement of cells with the surrounding scaffold material. Cell viability analysis revealed the creation of a core region of dead cells surrounded by healthy, viable cell layers at the periphery following long-term culture. These observations closely matched with those of native and in vivo tumors. Based on these results, this study established a rapidly reproducible surface tension-based fabrication technique for making spherical hydrogel millibeads and demonstrated the potential of this method in creating engineered 3D tumor tissues. It is envisioned that the developed hydrogel millibead system will facilitate the formation of physiologically relevant in vitro tumor models which will closely simulate the native tumor microenvironmental conditions and could enable future high-throughput testing of different anticancer drugs in preclinical trials.
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Affiliation(s)
- Shantanu Pradhan
- Department of Chemical Engineering, Auburn University , Auburn, Alabama 36849, United States
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35
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36
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Lu Y, Darne CD, Tan IC, Zhu B, Hall MA, Lazard ZW, Davis AR, Simpson L, Sevick-Muraca EM, Olmsted-Davis EA. Far-red fluorescence gene reporter tomography for determination of placement and viability of cell-based gene therapies. OPTICS EXPRESS 2013; 21:24129-24138. [PMID: 24104323 PMCID: PMC3796689 DOI: 10.1364/oe.21.024129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 09/02/2013] [Accepted: 09/15/2013] [Indexed: 06/02/2023]
Abstract
Non-invasive injectable cellular therapeutic strategies based on sustained delivery of physiological levels of BMP-2 for spinal fusion are emerging as promising alternatives, which could provide sufficient fusion without the associated surgical risks. However, these injectable therapies are dependent on bone formation occurring only at the specific target region. In this study, we developed and deployed fluorescence gene reporter tomography (FGRT) to provide information on in vivo cell localization and viability. This information is sought to confirm the ideal placement of the materials with respect to the area where early bone reaction is required, ultimately providing three dimensional data about the future fusion. However, because almost all conventional fluorescence gene reporters require visible excitation wavelengths, current in vivo imaging of fluorescent proteins is limited by high tissue absorption and confounding autofluorescence. We previously administered fibroblasts engineered to produce BMP-2, but is difficult to determine 3-D information of placement prior to bone formation. Herein we used the far-red fluorescence gene reporter, IFP1.4 to report the position and viability of fibroblasts and developed 3-D tomography to provide placement information. A custom small animal, far-red fluorescence tomography system integrated into a commercial CT scanner was used to assess IFP1.4 fluorescence and to demark 3-D placement of encapsulated fibroblasts with respect to the vertebrae and early bone formation as assessed from CT. The results from three experiments showed that the placement of the materials within the spine could be detected. This work shows that in vivo fluorescence gene reporter tomography of cell-based gene therapy is feasible and could help guide cell-based therapies in preclinical models.
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Affiliation(s)
- Yujie Lu
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
| | - Chinmay D. Darne
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
| | - I-Chih Tan
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
| | - Banghe Zhu
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
| | - Mary A. Hall
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
| | - ZaWaunyka W. Lazard
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas,
USA
| | - Alan R. Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas,
USA
| | - LaShan Simpson
- Bioengineering Department, Rice University, Houston, Texas,
USA
- Current address: Department of Agricultural and Biological Engineering at Mississippi State University, Mississippi State, Mississippi,
USA
| | - Eva M. Sevick-Muraca
- Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas,
USA
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37
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Sonnet C, Simpson CL, Olabisi RM, Sullivan K, Lazard Z, Gugala Z, Peroni JF, Weh JM, Davis AR, West JL, Olmsted-Davis EA. Rapid healing of femoral defects in rats with low dose sustained BMP2 expression from PEGDA hydrogel microspheres. J Orthop Res 2013; 31:1597-604. [PMID: 23832813 DOI: 10.1002/jor.22407] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 05/13/2013] [Indexed: 02/04/2023]
Abstract
Current strategies for bone regeneration after traumatic injury often fail to provide adequate healing and integration. Here, we combined the poly (ethylene glycol) diacrylate (PEGDA) hydrogel with allogeneic "carrier" cells transduced with an adenovirus expressing BMP2. The system is unique in that the biomaterial encapsulates the cells, shielding them and thus suppressing destructive inflammatory processes. Using this system, complete healing of a 5 mm-long femur defect in a rat model occurs in under 3 weeks, through secretion of 100-fold lower levels of protein as compared to doses of recombinant BMP2 protein used in studies which lead to healing in 2-3 months. New bone formation was evaluated radiographically, histologically, and biomechanically at 2, 3, 6, 9, and 12 weeks after surgery. Rapid bone formation bridged the defect area and reliably integrated into the adjacent skeletal bone as early as 2 weeks. At 3 weeks, biomechanical analysis showed the new bone to possess 79% of torsional strength of the intact contralateral femur. Histological evaluation showed normal bone healing, with no infiltration of inflammatory cells with the bone being stable approximately 1 year later. We propose that these osteoinductive microspheres offer a more efficacious and safer clinical option over the use of rhBMP2.
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Affiliation(s)
- Corinne Sonnet
- Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Alkek Building, Room N1010, Houston, Texas 77030, USA
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Xiang L, Ma L, Wang T, Wei N, Gong P. Proper size of the 3-dimensional periodontal ligament stem cell (3D PDLSC) sphere is vital for cell viability. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 117:121-2. [PMID: 23992959 DOI: 10.1016/j.oooo.2013.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 05/31/2013] [Indexed: 02/05/2023]
Affiliation(s)
- Lin Xiang
- Faculty, State Key Laboratory of Oral Diseases and Dental Implant Center, West China Hospital of Stomatology, Sichuan University, No. 14, Third Section, Renmin Nan Road, Chengdu, Sichuan 610041, China
| | - Li Ma
- Faculty, State Key Laboratory of Oral Diseases and Dental Implant Center, West China Hospital of Stomatology, Sichuan University, No. 14, Third Section, Renmin Nan Road, Chengdu, Sichuan 610041, China
| | - Tianlu Wang
- Faculty, State Key Laboratory of Oral Diseases and Dental Implant Center, West China Hospital of Stomatology, Sichuan University, No. 14, Third Section, Renmin Nan Road, Chengdu, Sichuan 610041, China
| | - Na Wei
- Faculty, State Key Laboratory of Oral Diseases and Dental Implant Center, West China Hospital of Stomatology, Sichuan University, No. 14, Third Section, Renmin Nan Road, Chengdu, Sichuan 610041, China
| | - Ping Gong
- Faculty, State Key Laboratory of Oral Diseases and Dental Implant Center, West China Hospital of Stomatology, Sichuan University, No. 14, Third Section, Renmin Nan Road, Chengdu, Sichuan 610041, China
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39
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Therapeutic cell encapsulation: Ten steps towards clinical translation. J Control Release 2013; 170:1-14. [DOI: 10.1016/j.jconrel.2013.04.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/05/2013] [Accepted: 04/22/2013] [Indexed: 12/23/2022]
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40
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Man Y, Wang P, Guo Y, Xiang L, Yang Y, Qu Y, Gong P, Deng L. Angiogenic and osteogenic potential of platelet-rich plasma and adipose-derived stem cell laden alginate microspheres. Biomaterials 2012; 33:8802-11. [PMID: 22981779 DOI: 10.1016/j.biomaterials.2012.08.054] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 08/23/2012] [Indexed: 12/25/2022]
Abstract
Improving vascularization of tissue-engineered bone can advance cell performance in vivo and further promote bone regeneration. How to achieve a functional vascular network within the construct is one of the biggest challenges so far. We hypothesized that a mixture of platelet-rich plasma (PRP) and adipose-derived stem cells (ADSCs) could endue the alginate microspheres with osteogenic and angiogenic potential. In vitro and in vivo studies were performed to investigate the potential of the PRP-ADSC-laden microspheres. Two intriguing observations were made in this study. First, we demonstrated that PRP sustained cell viability and meanwhile promoted cell migration from the interior of alginate microspheres to the surface. This phenomenon indicated that encapsulated cells have the potential to directly and actively participate into the regeneration process. Second, in vivo, a blood vessel network was found within the 10% PRP and 15% PRP-ADSC implants, which was associated with a significant increase in mineralization. It suggested that the PRP-ADSC-laden microspheres did enhance the vascularization and mineralization. In summary, this strategy not only provides a micro-invasive therapy for bone regeneration, but also could be incorporated with other matrices for extended application.
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Affiliation(s)
- Yi Man
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China
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41
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Salisbury E, Rodenberg E, Sonnet C, Hipp J, Gannon FH, Vadakkan TJ, Dickinson ME, Olmsted-Davis EA, Davis AR. Sensory nerve induced inflammation contributes to heterotopic ossification. J Cell Biochem 2012; 112:2748-58. [PMID: 21678472 DOI: 10.1002/jcb.23225] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heterotopic ossification (HO), or bone formation in soft tissues, is often the result of traumatic injury. Much evidence has linked the release of BMPs (bone morphogenetic proteins) upon injury to this process. HO was once thought to be a rare occurrence, but recent statistics from the military suggest that as many as 60% of traumatic injuries, resulting from bomb blasts, have associated HO. In this study, we attempt to define the role of peripheral nerves in this process. Since BMP2 has been shown previously to induce release of the neuroinflammatory molecules, substance P (SP) and calcitonin gene related peptide (CGRP), from peripheral, sensory neurons, we examined this process in vivo. SP and CGRP are rapidly expressed upon delivery of BMP2 and remain elevated throughout bone formation. In animals lacking functional sensory neurons (TRPV1(-/-) ), BMP2-mediated increases in SP and CGRP were suppressed as compared to the normal animals, and HO was dramatically inhibited in these deficient mice, suggesting that neuroinflammation plays a functional role. Mast cells, known to be recruited by SP and CGRP, were elevated after BMP2 induction. These mast cells were localized to the nerve structures and underwent degranulation. When degranulation was inhibited using cromolyn, HO was again reduced significantly. Immunohistochemical analysis revealed nerves expressing the stem cell markers nanog and Klf4, as well as the osteoblast marker osterix, after BMP2 induction, in mice treated with cromolyn. The data collectively suggest that BMP2 can act directly on sensory neurons to induce neurogenic inflammation, resulting in nerve remodeling and the migration/release of osteogenic and other stem cells from the nerve. Further, blocking this process significantly reduces HO, suggesting that the stem cell population contributes to bone formation.
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Affiliation(s)
- Elizabeth Salisbury
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA
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Rapid Heterotrophic Ossification with Cryopreserved Poly(ethylene glycol-) Microencapsulated BMP2-Expressing MSCs. Int J Biomater 2012; 2012:861794. [PMID: 22500171 PMCID: PMC3296315 DOI: 10.1155/2012/861794] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 10/09/2011] [Indexed: 12/29/2022] Open
Abstract
Autologous bone grafting is the most effective treatment for long-bone nonunions, but it poses considerable risks to donors, necessitating the development of alternative therapeutics. Poly(ethylene glycol) (PEG) microencapsulation and BMP2 transgene delivery are being developed together to induce rapid bone formation. However, methods to make these treatments available for clinical applications are presently lacking. In this study we used mesenchymal stem cells (MSCs) due to their ease of harvest, replication potential, and immunomodulatory capabilities. MSCs were from sheep and pig due to their appeal as large animal models for bone nonunion. We demonstrated that cryopreservation of these microencapsulated MSCs did not affect their cell viability, adenoviral BMP2 production, or ability to initiate bone formation. Additionally, microspheres showed no appreciable damage from cryopreservation when examined with light and electron microscopy. These results validate the use of cryopreservation in preserving the viability and functionality of PEG-encapsulated BMP2-transduced MSCs.
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Young CJ, Poole-Warren LA, Martens PJ. Combining submerged electrospray and UV photopolymerization for production of synthetic hydrogel microspheres for cell encapsulation. Biotechnol Bioeng 2012; 109:1561-70. [PMID: 22234803 DOI: 10.1002/bit.24430] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/17/2011] [Accepted: 12/20/2011] [Indexed: 01/28/2023]
Abstract
Microencapsulation within hydrogel microspheres holds much promise for drug and cell delivery applications. Synthetic hydrogels have many advantages over more commonly used natural materials such as alginate, however their use has been limited due to a lack of appropriate methods for manufacturing these microspheres under conditions compatible with sensitive proteins or cells. This study investigated the effect of flow rate and voltage on size and uniformity of the hydrogel microspheres produced via submerged electrospray combined with UV photopolymerization. In addition, the mechanical properties and cell survival within microspheres was studied. A poly(vinyl alcohol) (PVA) macromer solution was sprayed in sunflower oil under flow rates between 1-100 µL/min and voltages 0-10 kV. The modes of spraying observed were similar to those previously reported for electrospraying in air. Spheres produced were smaller for lower flow rates and higher voltages and mean size could be tailored from 50 to 1,500 µm. The microspheres exhibited a smooth, spherical morphology, did not aggregate and the compressive modulus of the spheres (350 kPa) was equivalent to bulk PVA (312 kPa). Finally, L929 fibroblasts were encapsulated within PVA microspheres and showed viability >90% after 24 h. This process shows great promise for the production of synthetic hydrogel microspheres, and specifically supports encapsulation of cells.
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Affiliation(s)
- Cara J Young
- Graduate School of Biomedical Engineering, The University of New South Wales, Level 5 Samuels Building, Sydney, New South Wales 2052, Australia
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Cell-Based Therapies for Spinal Fusion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 760:148-73. [DOI: 10.1007/978-1-4614-4090-1_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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45
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Zhang W, He X. Microencapsulating and Banking Living Cells for Cell-Based Medicine. JOURNAL OF HEALTHCARE ENGINEERING 2011; 2:427-446. [PMID: 22180835 DOI: 10.1260/2040-2295.2.4.427] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A major challenge to the eventual success of the emerging cell-based medicine such as tissue engineering, regenerative medicine, and cell transplantation is the limited availability of the desired cell sources. This challenge can be addressed by cell microencapsulation to overcome the undesired immune response (i.e., to achieve immunoisolation) so that non-autologous cells can be used to treat human diseases, and by cell/tissue preservation to bank living cells for wide distribution to end users so that they are readily available when needed in the future. This review summarizes the status quo of research in both cell microencapsulation and banking the microencapsulated cells. It is concluded with a brief outlook of future research directions in this important field.
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Affiliation(s)
- Wujie Zhang
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210
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Schroeder JE, Mosheiff R. Tissue engineering approaches for bone repair: concepts and evidence. Injury 2011; 42:609-13. [PMID: 21489529 DOI: 10.1016/j.injury.2011.03.029] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 03/17/2011] [Indexed: 02/02/2023]
Abstract
Over the last decades, the medical world has advanced dramatically in the understanding of fracture repair. The three components needed for fracture healing are osteoconduction, osteoinduction and osteogenesis. With newly designed scaffolds, ex vivo produced growth factors and isolated stem cells, most of the challenges of critical size bone defects have been resolved in vitro, and in some cases in animal models as well. However, there are still challenges needed to be overcome before these technologies can be fully converted from the bench to the bedside. These technological and biological advancements need to be converted to mass production of affordable products that can be used in every part of the world. Vascularity, full substation of scaffolds by native bone, and bio-safety are the three most critical steps to be challenged before reaching the clinical setting.
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Affiliation(s)
- Josh E Schroeder
- Orthopedic Surgery Department, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Flake MM, Nguyen PK, Scott RA, Vandiver LR, Willits RK, Elbert DL. Poly(ethylene glycol) microparticles produced by precipitation polymerization in aqueous solution. Biomacromolecules 2011; 12:844-50. [PMID: 21341681 DOI: 10.1021/bm1011695] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Methods were developed to perform precipitation photopolymerization of PEG-diacrylate. Previously, comonomers have been added to PEG when precipitation polymerization was desired. In the present method, the LCST of the PEG itself was lowered by the addition of the kosmotropic salt sodium sulfate to an aqueous solution. Typical of a precipitation polymerization, small microparticles or microspheres (1-5 μm) resulted with relatively low polydispersity. However, aggregate formation was often severe, presumably because of a lack of stabilization of the phase-separated colloids. Microparticles were also produced by copoymerization of PEG-diacrylate with acrylic acid or aminoethylmethacrylate. The comonomers affected the zeta potential of the formed microparticles but not the size. The carboxyl groups of acrylic-acid-containing PEG microparticles were activated, and scaffolds were formed by mixing with amine-containing PEG microparticles. Although the scaffolds were relatively weak, human hepatoma cells showed excellent viability when present during microparticle cross-linking.
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Affiliation(s)
- Megan M Flake
- Department of Biomedical Engineering and Center for Materials Innovation, Washington University, St. Louis, Missouri, USA
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