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Simon Young

Bio: Simon Young is an academic researcher from University of Texas Health Science Center at Houston. The author has contributed to research in topics: Bone regeneration & Medicine. The author has an hindex of 23, co-authored 57 publications receiving 3486 citations. Previous affiliations of Simon Young include University of Texas System & Harvard University.


Papers
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Journal ArticleDOI
TL;DR: This review will emphasize how biomolecules released from gelatin controlled-release systems are able to retain their biological activity, allowing for their use in tissue engineering, therapeutic angiogenesis, gene therapy, and drug delivery applications.

996 citations

Journal ArticleDOI
01 Nov 2008-Bone
TL;DR: The results indicate that delivery of both growth factors may enhance bone bridging and union of the critical size defect compared to delivery of BMP-2 alone and suggests an interplay between these growth factors for early bone regeneration.

545 citations

Journal ArticleDOI
TL;DR: The protocol for one such model, the rat calvarial defect, is described, which allows for evaluation of biomaterials and bone tissue engineering approaches within a reproducible, non-load-bearing orthotopic site.
Abstract: Animal models that are reliably reproducible, appropriate analogs to the clinical condition they are used to investigate, and that offer minimal morbidity and periprocedural mortality to the subject, are the keystone to the preclinical development of translational technologies. For bone tissue engineering, a number of small animal models exist. Here we describe the protocol for one such model, the rat calvarial defect. This versatile model allows for evaluation of biomaterials and bone tissue engineering approaches within a reproducible, non-load-bearing orthotopic site. Crucial steps for ensuring appropriate experimental control and troubleshooting tips learned through extensive experience with this model are provided. The surgical procedure itself takes ∼30 min to complete, with ∼2 h of perioperative care, and tissue collection is generally performed 4-12 weeks postoperatively. Several analytical techniques are presented, which evaluate the cellular and extracellular matrix components, functionality and mineralization, including histological, mechanical and radiographic methods.

497 citations

Journal ArticleDOI
TL;DR: In this review, injectable materials that form scaffolds or networks capable of both replacing tissue function early after delivery and supporting tissue regeneration over a time period of weeks to months are examined.
Abstract: Engineering complex tissues requires a precisely formulated combination of cells, spatiotemporally released bioactive factors, and a specialized scaffold support system. Injectable materials, particularly those delivered in aqueous solution, are considered ideal delivery vehicles for cells and bioactive factors and can also be delivered through minimally invasive methods and fill complex 3D shapes. In this review, we examine injectable materials that form scaffolds or networks capable of both replacing tissue function early after delivery and supporting tissue regeneration over a time period of weeks to months. The use of these materials for tissue engineering within the craniofacial complex is challenging but ideal as many highly specialized and functional tissues reside within a small volume in the craniofacial structures and the need for minimally invasive interventions is desirable due to aesthetic considerations. Current biomaterials and strategies used to treat craniofacial defects are examined, followed by a review of craniofacial tissue engineering, and finally an examination of current technologies used for injectable scaffold development and drug and cell delivery using these materials.

263 citations

Journal ArticleDOI
TL;DR: The dose effect of dual delivery of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) on bone regeneration was investigated in a rat cranial critical-size defect and the addition of VEGF was unable to reverse this decrease in PBF, although improvements in the number of bridged defects did occur in some groups.
Abstract: The dose effect of dual delivery of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) on bone regeneration was investigated in a rat cranial critical-size defect (CSD). It was hypothesized that decreasing amounts of BMP-2 would result in a dose-dependent decrease in bone formation, and that this reduction in bone formation could be reversed by adding increasing amounts of VEGF. In vitro release kinetics of VEGF or BMP-2 were examined over 28 days. Next, scaffolds were implanted within a rat cranial CSD containing different combinations of both BMP-2 and VEGF. At 12 weeks, samples were analyzed using microcomputed tomography and histology. In vitro, VEGF and BMP-2 exhibited burst release in the first 24 h followed by a significant decrease in release rate over 27 days. Overall, BMP-2 had a more sustained release versus VEGF. An in vivo dose-dependent decrease in percentage of bone fill (PBF) was observed for BMP-2. The addition of VEGF was unable to reverse this decrease in PBF, although improvements in the number of bridged defects did occur in some groups. This suggests that for this particular model simultaneous release of BMP-2 and VEGF does not increase bone formation over BMP-2 alone at 12 weeks.

246 citations


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Journal ArticleDOI
TL;DR: In this review, recent advances in bone scaffolds are highlighted and aspects that still need to be improved are discussed.

1,737 citations

Journal ArticleDOI
TL;DR: This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.
Abstract: Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. In order to fit functional demand, materials with desired physical, chemical, biological, biomechanical and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.

1,712 citations

DOI
18 Feb 2015

1,457 citations

Journal ArticleDOI
TL;DR: A wide range of natural-origin polymers with special focus on proteins and polysaccharides that are being used in research, or might be potentially useful as carriers systems for active biomolecules or as cell carriers with application in the tissue engineering field targeting several biological tissues are overviewed.

1,269 citations