Injectable and degradable Poly(oligoethylene glycol methacrylate)-based hydrogels-synthetic versatility for improved biomaterial designBakaic E, Smeets N, Imbrogno S and Hoare TOral #327.3 on Friday, May 20 from 14:00 to 15:00 in room 524 during World Biomaterials Congress, Montreal, May 2016.
Introduction: Poly(ethylene glycol) (PEG)-based hydrogels are attractive biomaterials due to their hydrophilic, non-cytotoxic and non-immunogenic properties[1]. We recently reported on in situ-gelling PEG-analogue hydrogels based on poly(oligoethylene glycol methacrylate) (POEGMA) formed via rapid gelation of hydrazide and aldehyde-functionalized POEGMA oligomers upon mixing that overcome many...Read More
Biomechanical models for radial distance determination by the rat vibrissal systemBirdwell JA, Solomon JH, Thajchayapong M, Taylor MA, Cheely M, Towal RB, Conradt J and Hartmann MJJournal of neurophysiology, 98(4), 2439-2455. (2007)
Rats use active, rhythmic movements of their whirs to acquire tactile information about three-dimensional object features. There are no receptors along the length of the whir; therefore all tactile information must be mechanically transduced back to receptors at the whir base. This raises the question: how might the rat determine the radial contact position of an object along the whir?...Read More
Highly oriented in situ gelling nanocomposite hydrogels as tissue engineering scaffolds for promoting directional cell growthDe France K, Yager KG, Chan KJ, Hoare TR and Cranston EDPoster #P.0554 on Thursday, May 19 from 15:00 to 16:30 in room 220BCD (P3) during World Biomaterials Congress, Montreal, May 2016
Introduction: Patterned hydrogels and polymer scaffolds have attracted attention as platforms for directed cell growth due to the significant impacts cell alignment has on tissue regeneration, mechanical properties and various other cell behaviours[1],[2]. However, most currently reported platforms require lengthy micropatterning steps[3]-[10], limiting their clinical applicability in vitro....Read More
Fully injectable hydrazone-thiosuccinimide and hydrazone-disulfide interpenetrating polymer network hydrogels by kinetically orthogonal cross-linking of functionalized PNIPAM and PVP precurGilbert T and Hoare TPoster #P.0058 on Thursday, May 19 from 15:00 to 16:30 in room 220BCD (P1) during World Biomaterials Congress, Montreal, May 2016.
Introduction: IPNs are produced by interlocking two chemically distinct networks in each other’s free volume fraction. This interlocking and the potential for segregation of the IPNs into inhomogeneous domains can cause mechanical properties and microstructures distinct from single network controls. Prior IPNs reported as injectable (desired for minimally invasive delivery) were polymerized...Read More
Engineering degradable ''smart'' biomedical hydrogels on multiple length scalesHoare TOral #339.2 on Friday, May 20 from 16:30 to 18:30 in room 520B during World Biomaterials Congress, Montreal, May 2016
While multiple types of smart, environmentally-responsive materials have been explored for a variety of biomedical applications (e.g. drug delivery, tissue engineering, bioimaging, etc.), their ultimate clinical use has been hampered by their lack of biologically-relevant degradation as well as challenges regarding their non-surgical administration to the body. These factors have particularly limited...Read More
The Aortic Wrap Procedure - A Surgical Method of Treating Age-Related Aortic Dilatation and StiffnessIliopoulos JPhD Thesis, University of New South Wales, Sydney. (2006)
Introduction: There is progressive stiffening and dilatation of the aorta and large elastic arteries with aging as a result of the repetitive cyclic stress they are exposed to throughout life. Aortic stiffening has a number of detrimental effects including an increase in aortic pulse wave velocity and early wave reflection, isolated systolic hypertension, ventricular-vascular mismatch, impaired...Read More
Characterization of the effect of microfracture surgery and angle of incidence on the structural properties of femoral boneLiang LD, Wagner A, Steeds J, Hurtig M and Gordon KStudies by Undergraduate Researchers at Guelph, 7(1), 56-61. (2013)
Microfracture surgery is one of the most common treatment options for knee osteoarthritis, a chronic inflammatory disease of the knee joint. However, a recent study by Theodoropoulos et al. (2012) has shown that there are significant variations in the angle of surgical awl used by surgeons in microfracture surgery as well as in the rehabiliation regimen prescribed following surgery. The purpose of...Read More
The effect of terminal sterilization on structural and biophysical properties of a decellularized collagen-based scaffold; implications for stem cell adhesionMatuska AM and McFetridge PSJ Biomed Mater Res Part B, 2014, pp 1-10
Terminal sterilization induces physical and chemical changes in the extracellular matrix (ECM) of ex vivo-derived biomaterials due to their aggressive mechanism of action. Prior studies have focused on how sterilization affects the mechanical integrity of tissue-based biomaterials but have rarely characterized effects on early cellular interaction, which is indicative of the biological response. Using...Read More
Static and Dynamic Compression Application and Removal on the Intervertebral Discs of Growing RatsMenard AL, Grimard G, Massol E, Londono I, Moldovan F and Villemure IJournal of Orthopaedic Research Month 2015, pp.1-9. (2015)
Fusionless implants are used to correct pediatric progressive spinal deformities, most of them spanning the intervertebral disc. This study aimed at investigating the effects of in vivo static versus dynamic compression application and removal on discs of growing rats. A microloading device applied compression. 48 immature rats (28 d.o.) were divided into two groups (43d, 53d). Each group included...Read More
Tissue engineered nucleus pulposus tissue formed on a porous calcium polyphosphate substrateSeguin CA, Grynpas MD, Pilliar RM, Waldman SD and Kandel RASpine, 29(12), 1299-1306. (2004)
STUDY DESIGN: This study describes the formation of nucleus pulposus tissue using a novel tissue engineering approach. OBJECTIVES: To determine if a construct composed of nucleus pulposus tissue on the surface of a calcium polyphosphate substrate could be formed in vitro with properties similar to native nucleus pulposus tissue.
ASTM F1717 - Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy ModelASTM International, West Conshohocken, PA, 2015, www.astm.org
Significance and Use
5.1 Spinal implants are generally composed of several components which, when connected together, form a spinal implant assembly. Spinal implant assemblies are designed to provide some stability to the spine while arthrodesis takes place. These test methods outline standard materials and methods for the evaluation of different spinal implant assemblies so...Read More
MachOne - Dynamic Mechanical Testing (MA056-SOP04-D v1)Hadjab I and Quenneville EBMM Inc. Laval (QC), Canada, Effective Date: December 3rd, 2014
Purpose This document describes a standard method to assess the frequency behavior of the dynamic mechanical properties of material through the complex Young’s (E*) or shear (G*) modulus using the MachOne mechanical tester. Analysis of the measurement results is part of a companion document (SW186-SOP04-D).
MachOne Analysis - Extraction of the Complex Modulus Components Following Dynamic Mechanical Testing (SW186-SOP04-D v1)Hadjab I and Quenneville EBMM Inc. Laval (QC), Canada, Effective Date: December 3rd, 2014
Purpose This procedure describes a method for the extraction of the complex modulus components (Young’s (E’ and E”) and shear (G’ and G”) modulus) following dynamic mechanical testing performed as per MA056-SOP04-D.
Scope This procedure can be used with any MachOne result file resulting from dynamic mechanical testing on a sample...Read More
Review Paper: Fifty years of brain tissue mechanical testing: From in vitro to in vivo investigationsChatelin S, Constantinesco A and Willinger RBiorheology 47 (2010) 255–276. DOI 10.3233/BIR-2010-0576
Beginning in the 1960s many studies have been performed to investigate the mechanical properties of brain. In this paper we point out the difficulties linked with in vitro experimental protocols as well as the advantages of using recently developed non-invasive in vivo techniques, such as magnetic resonance elastography. Results of in vitro and in vivo work are compared, emphasizing the specificities...Read More
Autonomously Self-Adhesive Hydrogels as Building Blocks for Additive ManufacturingDeng X, Attalla R, Sadowski LP, Chen M, Majcher MJ, Urosev I, Yin D-C, Selvaganapathy PR, Filipe CDM and Hoare TBiomacromolecules 2017, Published Online, doi: 10.1021/acs.biomac.7b01243
We report a simple method of preparing autonomous and rapid self-adhesive hydrogels and their use as building blocks for additive manufacturing of functional tissue scaffolds. Dynamic crosslinking between 2-aminophenylboronic acid-functionalized hyaluronic acid and poly(vinyl alcohol) yields hydrogels that recover their mechanical integrity within one minute after cutting or shear under both neutral...Read More
In Situ Cross-Linking of Poly (vinyl alcohol)/Graphene Oxide–Polyethylene Glycol Nanocomposite Hydrogels as Artificial Cartilage Replacement: Intercalation Structure, Unconfined Compressive Behavior, and Biotribological BehaviorsMeng, Yeqiao; Ye, Lin; Coates, Phil; Twigg, PeterJ. Phys. Chem. C, 2018, 122 (5), pp 3157–3167 DOI: 10.1021/acs.jpcc.7b12465
Poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposite hydrogel as artificial cartilage replacement was prepared via freezing/thawing method by introducing polyethylene glycol (PEG). Efficient grafting of PVA molecules onto GO surface was realized by formation of hydrogen bonding, resulting in exfoliation and uniform distribution of GO in PVA matrix. By introduction of appropriate content of GO,...Read More
Growth and Characterization of Multicellular Spheroids in Cellulose Derived Hydrogels as an Artificial Three-Dimensional ScaffoldMelissa CampbellUniversity of Toronto
The Young’s modulus of each hydrogel was performed on a MachOne Mechanical tester (BMM Inc., QC) using cyclic compression and parallel plate geometry. The hydrogels for testing were pre-formed into disks measuring 3.25 mm in height by 14 mm in diameter. Compression was executed by applying 20% strain at a rate of 0.03 mm/s in the +z direction. The Young’s modulus of the hydrogels was...Read More
Experimental and finite element analyses of bone strains in the growing rat tibia induced by in vivo axial compressionTanvir Mustafy, Irène Londono, Isabelle VillemureJournal of the Mechanical Behavior of Biomedical Materials
The objective of this study was to develop and validate a voxel based F