1
|
Emonson NS, Dharmasiri B, Gordon EB, Borkar A, Newman B, Wickramasingha YA, Coia P, Harte T, Newton J, Allardyce BJ, Stojcevski F, Kaplan DL, Henderson LC. Biomedical Applications of Electro-Initiated Polymerisation on Ti6Al4 V Titanium Alloy using Silk Fibroin Coatings for Antibiotic Delivery and Improved Cell Metabolism. Chempluschem 2023:e202300555. [PMID: 38036452 DOI: 10.1002/cplu.202300555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/02/2023]
Abstract
Silk fibroin interactions with metallic surfaces can provide utility for medical materials and devices. Toward this goal, titanium alloy (Ti6Al4 V) was covalently grafted with polyacrylamide via electrochemically reducing 4-nitrobenzene diazonium salt in the presence of acrylamide. Analysis of the modified surfaces with FT-IR spectra, SEM and AFM were consistent with surface grafting. Functionalised titanium samples with a silk fibroin membrane, with and without impregnated therapeutics, were used to assess cytocompatibility and drug delivery. Initial cytocompatibility experiments using fibroblasts showed that the functionalised samples, both with and without silk fibroin coatings, supported significant increases between 72-136 % in cell metabolism, compared to the controls after 7 days. A 7-days release profiling showed consistent bacterial inhibition through gentamicin release with average inhibition zones of 239 mm2 . Over a 5-week period, silk fibroin coated samples, both with and without growth factors, supported better human mesenchymal stem cell metabolism with increases reaching 1031 % and 388 %, respectively, compared to samples without the silk fibroin coating with.
Collapse
Affiliation(s)
- Nicholas S Emonson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Bhagya Dharmasiri
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Edward B Gordon
- Biomedical Engineering Department, Tufts University, Medford, MA, 02155, USA
| | - Ameya Borkar
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Ben Newman
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | | | - Piers Coia
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Timothy Harte
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Jazmyn Newton
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Benjamin J Allardyce
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - Filip Stojcevski
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| | - David L Kaplan
- Biomedical Engineering Department, Tufts University, Medford, MA, 02155, USA
| | - Luke C Henderson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC, 3216, Australia
| |
Collapse
|
2
|
Harte T, Dharmasiri B, Dobhal GS, Walsh TR, Henderson LC. Accelerated lithium-ion diffusion via a ligand 'hopping' mechanism in lithium enriched solvate ionic liquids. Phys Chem Chem Phys 2023; 25:29614-29623. [PMID: 37880987 DOI: 10.1039/d3cp04666d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Solvate ionic liquids (SILs), equimolar amounts of lithium salts and polyether glymes, are well studied highly customisable "designer solvents". Herein the physical, thermal and ion mobility properties of SILs with increased LiTFSI (LiTFSA) concentration, with ligand 1 : >1 LiTFSI stoichiometric ratios, are presented. It was found that between 60-80 °C, the lithium cation diffuses up to 4 times faster than the corresponding anion or ligand (glyme). These systems varied from viscous liquids to self-supporting gels, though were found to thin exponentially when heated to mild temperatures (50-60 °C). They were also found to be thermally stable, up to 200 °C, well in excess of normal operating temperatures. Ion mobility, assessed under an electric potential via ionic conductivity, showed the benefit of SIL optimisation for attaining greater concentrations of Li+ cations to store charge during supercapacitor charging and discharging. Molecular dynamics simulations interrogate the mechanism of enhanced diffusion at high temperatures, revealing a lithium hopping mechanism that implicates the glyme in bridging two lithiums through changes in the denticity.
Collapse
Affiliation(s)
- Timothy Harte
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Bhagya Dharmasiri
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Garima S Dobhal
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Tiffany R Walsh
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Luke C Henderson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| |
Collapse
|
3
|
Hayne DJ, Dharmasiri B, Stojcevski F, Eyckens DJ, Hooper JF, Henderson LC. Carbon fibre surface modification facilitated by silver-catalysed radical decarboxylation. Chem Commun (Camb) 2023; 59:9860-9863. [PMID: 37490281 DOI: 10.1039/d3cc02482b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
A silver catalysed radical decarboxylation process was used to graft a copolymer (4 : 1; methylacrylate/acrylic acid) onto short carbon fibres. Surface grafting was confirmed by XPS, SEM and TGA, suggesting that the polymer accounted for 10% of the modified materials mass. Incorporation of these surface enhanced carbon fibres into an epoxy resin gave composites demonstrating an increase in ductility and a clear change in failure mode from adhesive, at the fibre-matrix interface, to cohesive, within the matrix polymer itself.
Collapse
Affiliation(s)
- David J Hayne
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216, Australia.
| | - Bhagya Dharmasiri
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216, Australia.
| | - Filip Stojcevski
- Defence Science and Technology Group, Fisherman's Bend, Port Melbourne, Victoria 3207, Australia
| | - Daniel J Eyckens
- Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Clayton, Victoria 3168, Australia
| | - Joel F Hooper
- Department of Chemistry, Monash University, Clayton 3800, Victoria, Australia.
| | - Luke C Henderson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216, Australia.
| |
Collapse
|
4
|
Eyckens DJ, Adcock JL, Blinco JP, Fairfull-Smith KE, Harris J, Vuković F, He S, Dharmasiri B, Walsh TR, Francis PS, Hendlmeier A, Henderson LC. Using Nitroxides to Enhance Carbon Fibre Interfacial Adhesion and As An Anchor for "Graft to" Surface Modification Strategies. Macromol Rapid Commun 2023:e2300274. [PMID: 37474483 DOI: 10.1002/marc.202300274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023]
Abstract
Nitroxide groups covalently grafted to carbon fibres were used as anchoring sites for TEMPO-terminated polymers (poly-n-butylacrylate and polystyrene) in a "graft to" surface modification strategy. All surface modified fibres were evaluated for their physical properties, showing that several treatments had enhanced the tensile strength and Young's modulus compared to the control fibres. Up to an 18% increase in tensile strength and 12% in Young's modulus were observed. Similarly, evaluation of interfacial shear strength in an epoxy polymer, showed improvements of up to 144% relative to the control sample. Interestingly, the polymer grafted surfaces showed smaller increases in interfacial shear strength compared to surfaces modified with a small molecule only. This counterintuitive result was attributed to incompatibility, both chemical and physical, of the grafted polymers to the surrounding epoxy matrix. Molecular dynamics simulations of the interface suggest that the diminished increase in mechanical shear strength observed for the polymer grafted surfaces may be due to the lack of exposed chain ends, whereas the small molecule grafted interface exclusively presents chain ends to the resin interface, resulting in good improvements in mechanical properties. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
| | - Jacqui L Adcock
- Deakin University, Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Waurn Ponds, Victoria, 3216, Australia
| | - James P Blinco
- School of Chemistry and Physics, Centre for Materials Science, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Kathryn E Fairfull-Smith
- School of Chemistry and Physics, Centre for Materials Science, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Jessica Harris
- School of Chemistry and Physics, Centre for Materials Science, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Filip Vuković
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Siyuan He
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Bhagya Dharmasiri
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Tiffany R Walsh
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Paul S Francis
- Deakin University, Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Waurn Ponds, Victoria, 3216, Australia
| | - Andreas Hendlmeier
- Aerostructures Innovation Research Hub, Swinburne University of Technology, Hawthorn, Melbourne, VIC, 3122, Australia
| | - Luke C Henderson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| |
Collapse
|
5
|
Emonson NS, Randall JD, Allardyce BJ, Stanfield MK, Dharmasiri B, Stojcevski F, Henderson LC. Promoting Silk Fibroin Adhesion to Stainless Steel Surfaces by Interface Tailoring. Chempluschem 2023; 88:e202200335. [PMID: 36449627 DOI: 10.1002/cplu.202200335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/07/2022] [Indexed: 11/11/2022]
Abstract
Bonding dissimilar materials has been a persistent challenge for decades. This paper presents a method to modify a stainless steel surface (316 L), routinely used in medical applications to enable the significant adhesion of a biopolymer (silk fibroin). The metallic surface was first covalently grafting with polyacrylamide, to enable a hydrogen bonding compatible surface. The polymerisation was initiated via the irreversible electrochemical reduction of a 4-nitrobenzene diazonium salt (20 mM), in the presence of an acrylamide monomer (1 M) at progressively faster scan rates (0.01 V/s to 1 V/s). Examination of the modified samples by FT-IR was consistent with successful surface modification, via observations of the acrylamide carbonyl (1600-1650 cm-1 ) was observed, with more intense peaks correlating to slower scan rates. Similar observations were made with respect to increasing surface polarity, assessed by water contact angle. Reductions of >60° were observed for the grafted surfaces, relative to the unmodified control materials, indicating a surface able to undergo significant hydrogen bonding. The adhesion of silk to the metallic surface was quantified using a lap shear test, effectively using silk fibroin as an adhesive. Adhesion improvements of 5-7-fold, from 4.1 MPa to 29.3 MPa per gram of silk fibroin, were observed for the treated samples, highlighting the beneficial effect of this surface treatment. The methods developed in this work can be transferred to any metallic (or conductive) surface and can be tailored to complement any desired interface.
Collapse
Affiliation(s)
- Nicholas S Emonson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - James D Randall
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Benjamin J Allardyce
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Melissa K Stanfield
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Bhagya Dharmasiri
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Filip Stojcevski
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Luke C Henderson
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| |
Collapse
|