Akron, OH, United States
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Smith Callahan L.A.,University of Akron | Xie S.,University of Akron | Barker I.A.,University of Warwick | Zheng J.,University of Akron | And 4 more authors.
Biomaterials | Year: 2013

End-functional PLLA nanofibers were fabricated into mats of random or aligned fibers and functionalized post-spinning using metal-free "click chemistry" with the peptide Tyr-Ile-Gly-Ser-Arg (YIGSR). Fibers that were both aligned and functionalized with YIGSR were found to significantly increase the fraction of mouse embryonic stem cells (mESC) expressing neuron-specific class III beta-tubulin (TUJ1), the level of neurite extension and gene expression for neural markers compared to mESC cultured on random fiber mats and unfunctionalized matrices. Precise functionalization of degradable polymers with bioactive peptides created translationally-relevant materials that capitalize on the advantages of both synthetic and natural systems, while mitigating the classic limitations of each. © 2013 Elsevier Ltd.


Yu J.,University of Akron | Lin F.,University of Akron | Lin P.,University of Akron | Gao Y.,University of Akron | And 2 more authors.
Macromolecules | Year: 2014

A new class of l-phenylalanine-based poly(ester urea)s (PEU) was developed that possess tunable mechanical properties and degradation rates. Our preliminary data have shown that 1,6-hexanediol-l-phenylalanine-based poly(ester urea)s possess an elastic modulus nearly double that of poly(lactic acid). The data in this article detail the synthesis of a series of l-phenylalanine-based poly(ester urea)s possessing a variation in diol chain length and how these subtle structural differences influence the mechanical properties and in vitro biodegradation rates. The mechanical data span a range of values that overlaps with several currently clinically available degradable polymers. Increasing the diol chain lengths increases the amount of flexible segment in the chemical structure, which results in reduced elastic modulus values and increased values of elongation at break. The l-phenylalanine-based poly(ester urea)s also exhibited a diol length dependent degradation process that varied between 1 and 5% over 16 weeks. Compared with PLLA, PEUs degrade more quickly, and the rate can be tuned by changing the diol chain length. © 2013 American Chemical Society.


Davis S.A.,The Cooper Union for the Advancement of Science and Art | Davis B.L.,Austen BioInnovation Institute
Current Sports Medicine Reports | Year: 2012

A variety of physiological changes are experienced by astronauts during both short- and long-duration space missions. These include space motion sickness, spatial disorientation, orthostatic hypotension, muscle atrophy, bone demineralization, increased cancer risk, and a compromised immune system. This review focuses on countermeasures used to moderate these changes, particularly exercise devices that have been used by National Aeronautics and Space Administration astronauts over the past six decades as countermeasures to muscle atrophy and bone loss. The use of these devices clearly has shown that a microgravity environment places unusual demands on both the equipment and the human users. While it is of paramount importance to overcome microgravityinduced musculoskeletal deconditioning, it also is imperative that the exercise system (i) is small and lightweight, (ii) does not require an external power source, (iii) produces 1g-like benefits to both bones and muscles, (iv) requires relatively short durations of exercise, and (v) does not affect the surrounding structure or environment negatively through noise and/or induced vibrations. Copyright © 2012 by the American College of Sports Medicine.


Zheng J.,University of Akron | Liu K.,University of Akron | Reneker D.H.,University of Akron | Becker M.L.,University of Akron | Becker M.L.,Austen BioInnovation Institute
Journal of the American Chemical Society | Year: 2012

A primary amine-derivatized 4-dibenzocyclooctynol (DIBO) was used to initiate the ring-opening polymerization of poly(γ-benzyl-l-glutamate) (DIBO-PBLG). This initiator yields well-defined PBLG polymers functionalized with DIBO at the chain termini. The DIBO end group further survives an electrospinning process that yields nanofibers that were then derivatized post-assembly with azide-functionalized gold nanoparticles. The availability of DIBO on the surface of the fibers is substantiated by fluorescence, SEM, and TEM measurements. Post-assembly functionalization of nanofiber constructs with bioactive groups can be facilitated easily using this process. © 2012 American Chemical Society.


Bois A.J.,Cleveland Clinic | Fening S.D.,Austen BioInnovation Institute | Fening S.D.,Summa Health System | Polster J.,Cleveland Clinic | And 2 more authors.
American Journal of Sports Medicine | Year: 2012

Background: Glenoid support is critical for stability of the glenohumeral joint. An accepted noninvasive method of quantifying glenoid bone loss does not exist. Purpose: To perform independent evaluations of the reliability and accuracy of standard 2-dimensional (2-D) and 3-dimensional (3-D) computed tomography (CT) measurements of glenoid bone deficiency. Study Design: Descriptive laboratory study. Methods: Two sawbone models were used; one served as a model for 2 anterior glenoid defects and the other for 2 anteroinferior defects. For each scapular model, predefect and defect data were collected for a total of 6 data sets. Each sample underwent 3-D laser scanning followed by CT scanning. Six physicians measured linear indicators of bone loss (defect length and width-to-length ratio) on both 2-D and 3-D CT and quantified bone loss using the glenoid index method on 2-D CT and using the glenoid index, ratio, and Pico methods on 3-D CT. The intraclass correlation coefficient (ICC) was used to assess agreement, and percentage error was used to compare radiographic and true measurements. Results: With use of 2-D CT, the glenoid index and defect length measurements had the least percentage error (-4.13% and 7.68%, respectively); agreement was very good (ICC, .81) for defect length only. With use of 3-D CT, defect length (0.29%) and the Pico 1 method (4.93%) had the least percentage error. Agreement was very good for all linear indicators of bone loss (range, .85-.90) and for the ratio linear and Pico surface area methods used to quantify bone loss (range, .84-.98). Overall, 3-D CT results demonstrated better agreement and accuracy compared to 2-D CT. Conclusion: None of the methods assessed in this study using 2-D CT was found to be valid, and therefore, 2-D CT is not recommended for these methods. However, the length of glenoid defects can be reliably and accurately measured on 3-D CT. The Pico and ratio techniques are most reliable; however, the Pico1 method accurately quantifies glenoid bone loss in both the anterior and anteroinferior locations. Future work is required to implement valid imaging techniques of glenoid bone loss into clinical practice. Clinical Relevance: This is one of the only studies to date that has investigated both the reliability and accuracy of multiple indicators and quantification methods that evaluate glenoid bone loss in anterior glenohumeral instability. These data are critical to ensure valid methods are used for preoperative assessment and to determine when a glenoid bone augmentation procedure is indicated. © 2012 The Author(s).


Douglas F.L.,Ewing Marion Kauffman Foundation | Douglas F.L.,Austen BioInnovation Institute | Narayanan V.K.,Drexel University | Mitchell L.,Ewing Marion Kauffman Foundation | Litan R.E.,Ewing Marion Kauffman Foundation
Nature Reviews Drug Discovery | Year: 2010

A lack of entrepreneurial behaviour has often been highlighted as a contributor to the decline in the research and development (R&D) productivity of the pharmaceutical industry. Here, we present an assessment of entrepreneurship in the industry, based on interviews with 26 former and current leaders of R&D departments at major pharmaceutical and biotechnology companies. Factors are highlighted that could be important in promoting entrepreneurial behaviour, which might serve as a catalyst for revitalizing R&D productivity. © 2010 Macmillan Publishers Limited. All rights reserved.


Kodali P.,University of Texas Health Science Center at Houston | Jones M.H.,Cleveland Clinic | Polster J.,Cleveland Clinic | Miniaci A.,Cleveland Clinic | Fening S.D.,Austen BioInnovation Institute
Journal of Shoulder and Elbow Surgery | Year: 2011

Background: Bone defects play a role in recurrent instability. There is no universal method to quantify humeral head defects. The purpose of this study is to assess the accuracy of 2-dimensional computed tomography (CT) scan measurements of Hill-Sachs lesions. Materials and methods: Six Hill-Sachs defects were created in anatomically shaped bone substitutes. The samples were scanned with a 3-dimensional laser scanner. Maximum width and depth were measured and used as the true measurement. The samples underwent routine CT scanning, and 5 physicians measured maximum width and depth on each plane independently. The intraclass correlation coefficient (ICC) was used to assess agreement. Percent error and paired t test were used for statistical analysis (P < .05 denoted significance). Results: The ICC between observers was 0.879 (95% confidence interval, 0.780-0.946) and 0.721 (95% confidence interval, 0.543-0.865) for the depth and width measurement, respectively. The ICC was good between individual observers and the true measurement (range, 0.765-0.956). Individual observers were more accurate in depth rather than width measurements. The mean overall percent error of the depth and width measurements for the 6 defects was calculated: coronal, 19.2% ± 13.6%; sagittal, 11.8% ± 8.2%; and axial, 13.6% ± 8.4%. Conclusions: The depth of Hill-Sachs lesions can be reliably assessed using CT scan. Observers consistently underestimated width in all imaging planes. Overall, sagittal- and axial-plane measurements are more accurate for evaluation of these defects than the coronal plane. Future studies using 3-dimensional CT may be helpful to further quantitatively assess the size of the Hill-Sachs lesion, including width and volume. © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees.


Zhou J.,University of Akron | Xie S.,University of Akron | Amond E.F.,University of Akron | Becker M.L.,University of Akron | Becker M.L.,Austen BioInnovation Institute
Macromolecules | Year: 2013

A series of low bandgap semi-random copolymers incorporating various ratios of two acceptor units - thienothiadiazole and benzothiadiazole - were synthesized by Pd-catalyzed Stille coupling. The polymer films exhibited broad and intense absorption spectra, covering the spectral range from 350 nm up to 1240 nm. The optical bandgaps and HOMO levels of the polymers were calculated from ultraviolet-visible spectroscopy and cyclic voltammetry measurements, respectively. By changing the ratio of the two acceptor monomers, the HOMO levels of the polymers were tuned from -4.42 to -5.28 eV and the optical bandgaps were varied from 1.00 to 1.14 eV. The results indicate our approach could be applied to the design and preparation of conjugated polymers with specifically desired energy levels and bandgaps for photovoltaic applications. © 2013 American Chemical Society.


Gebhart J.J.,Case Western Reserve University | Miniaci A.,Cleveland Clinic | Fening S.D.,Austen BioInnovation Institute | Fening S.D.,Summa Health System
Journal of Shoulder and Elbow Surgery | Year: 2013

Background: Estimation of size, shape, and curvature of the humeral head is important for shoulder replacement procedures and allograft transplantation, especially as we try to recreate normal anatomy. The purpose of this study was to investigate the value of various anthropometric measurements for predicting humeral head curvature. Materials and methods: Cadaveric humeri were scanned with a 3-dimensional laser scanner. Length of the humerus, epicondylar breadth, and humeral head curvature were determined using data from the scans. A linear regression was performed for the length of the humerus, epicondylar breadth, gender, age, height, and weight. A stepwise linear regression with forward and backward substitution (α = 0.15) was performed for the most predictive variables from the initial linear regression. An equation for the prediction of humeral head radius of curvature was generated using this data. Results: The most predictive factors (R2 > 0.5) were epicondylar breadth, height, sex, and humeral length. These 4 factors were included in a forward and backward stepwise regression. The resulting equation had an R2 value of 0.812. Conclusion: Of the predicted measurements evaluated, patient height, maximum humeral length, epicondylar breadth, and gender were most correlated with humeral head curvature. Including these 4 factors in a linear regression model increased the R2 value to 0.812. If only a single measurement can be used to size the humeral head curvature, patient height will give the same accuracy as epicondylar breadth and can more easily be obtained. A patient's height can help accurately predict the patient's humeral head anatomy. © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees.


Grant
Agency: Department of Health and Human Services | Branch: | Program: STTR | Phase: Phase I | Award Amount: 222.91K | Year: 2014

DESCRIPTION (provided by applicant): While minimally invasive surgery has transformed the practice of surgery, access to implants for removal or alteration still requires surgery which generates risk and high cost. A next-generation approach is non-invasive, where implants are adjusted without an incision. There are clear applications in all fields of surgery, but particulary in orthopaedics where implants require frequent adjustment. One condition, early onset scoliosis, is disproportionally responsible for high cost and poor patient outcomes. Scoliosis, a pathological lateral curvature of the spine greater than 10, affects 2-4% of the population, or an estimated 6 million people in the United States. If left untreated, early onset scoliosis can cause damaging spinal deformity early in life; thus affecting other aspects of the child's health. There s no known cure for early onset idiopathic scoliosis. The most common surgical treatment of early onset scoliosis utilizes growing rods. In this procedure,

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