Publications by authors named "Thomas E Paterson"

6 Publications

  • Page 1 of 1

Electrospun Scaffolds Containing Silver-Doped Hydroxyapatite with Antimicrobial Properties for Applications in Orthopedic and Dental Bone Surgery.

J Funct Biomater 2020 Aug 14;11(3). Epub 2020 Aug 14.

School of Clinical Dentistry, University of Sheffield, Shefield 0114, UK.

Preventing the development of osteomyelitis while enhancing bone regeneration is challenging, with relatively little progress to date in translating promising technologies to the clinic. Nanoscale hydroxyapatite (nHA) has been employed as a bone graft substitute, and recent work has shown that it may be modified with silver to introduce antimicrobial activity against known pathogens. The aim of this study was to incorporate silver-doped nHA into electrospun scaffolds for applications in bone repair. Silver-doped nHA was produced using a modified, rapid mixing, wet precipitation method at 2, 5, 10 mol.% silver. The silver-doped nHA was added at 20 wt.% to a polycaprolactone solution for electrospinning. Bacteria studies demonstrated reduced bacterial presence, with and undetectable after 96 h of exposure. Mesenchymal stem cells (MSCs) were used to study both toxicity and osteogenicity of the scaffolds using PrestoBlue and alkaline phosphatase (ALP) assays. Innovative silver nHA scaffolds significantly reduced . and bacterial populations while maintaining cytocompatibility with mammalian cells and enhancing the differentiation of MSCs into osteoblasts. It was concluded that silver-doped nHA containing scaffolds have the potential to act as an antimicrobial device while supporting bone tissue healing for applications in orthopedic and dental bone surgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jfb11030058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7563183PMC
August 2020

Multifunctional Copper-Containing Mesoporous Glass Nanoparticles as Antibacterial and Proangiogenic Agents for Chronic Wounds.

Front Bioeng Biotechnol 2020 31;8:246. Epub 2020 Mar 31.

School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom.

The physiological wound healing process involves a cascade of events which could be affected by several factors resulting in chronic, non-healing wounds. The latter represent a great burden especially when bacterial biofilms are formed. The rise in antibiotic resistance amongst infectious microorganisms leads to the need of novel approaches to treat this clinical issue. In this context, the use of advanced biomaterials, which can enhance the physiological expression and secretion of the growth factors involved in the wound healing process, is gaining increasing attention as a robust and appealing alternative approach. Among them, mesoporous glasses are of particular interest due to their excellent textural properties and to the possibility of incorporating and releasing specific therapeutic species, such as metallic ions. One of the most attractive therapeutic ions is copper thanks to its proangiogenic and antibacterial effects. In this contribution, copper containing mesoporous glass nanoparticles were proposed as a multifunctional device to treat chronic wounds. The developed nanoparticles evidenced a very high specific surface area (740 m/g), uniform pores of 4 nm and an almost total release of the therapeutic ion within 72 h of soaking. The produced nanoparticles were biocompatible and, when tested against Gram positive and Gram negative bacterial species, demonstrated antibacterial activity against both planktonic and biofilm bacteria in 2D cell monolayers, and in a 3D human model of infected skin. Their proangiogenic effect was tested with both the aortic ring and the chick chorioallantoic membrane assays and an increase in endothelial cell outgrowth at a concentration range between 30 and 300 ng/mL was shown. Overall, in this study biocompatible, multifunctional Cu-containing mesoporous glass nanoparticles were successfully produced and demonstrated to exert both antibacterial and proangiogenic effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fbioe.2020.00246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7136418PMC
March 2020

Use of silver-based additives for the development of antibacterial functionality in Laser Sintered polyamide 12 parts.

Sci Rep 2020 01 21;10(1):892. Epub 2020 Jan 21.

Department of Mechanical Engineering, University of Sheffield, Royal Exchange Building, 64 Garden Street, Sheffield, S1 4BJ, UK.

Infectious diseases (exacerbated by antimicrobial resistance) cause death, loss of quality of life and economic burden globally. Materials with inherent antimicrobial properties offer the potential to reduce the spread of infection through transfer via surfaces or solutions, or to directly reduce microbial numbers in a host if used as implants. Additive Manufacturing (AM) techniques offer shorter supply chains, faster delivery, mass customisation and reduced unit costs, as well as highly complicated part geometries which are potentially harder to clean and sterilise. Here, we present a new approach to introducing antibacterial properties into AM, using Laser Sintering, by combining antimicrobial and base polymer powders prior to processing. We demonstrate that the mechanical properties of the resultant composite parts are similar to standard polymer parts and reveal the mode of the antibacterial activity. We show that antibacterial activity is modulated by the presence of obstructing compounds in different experimental media, which will inform appropriate use cases. We show that the material is not toxic to mammalian cells. This material could be quickly used for commercial products, and our approach could be adopted more generally to add new functionality to Laser Sintered parts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-57686-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6972821PMC
January 2020

Ag modified mesoporous bioactive glass nanoparticles for enhanced antibacterial activity in 3D infected skin model.

Mater Sci Eng C Mater Biol Appl 2019 Oct 17;103:109764. Epub 2019 May 17.

Institute of Biomaterials, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address:

Bioactive glasses (BG) are versatile materials for various biomedical applications, including bone regeneration and wound healing, due to their bone bonding, antibacterial, osteogenic, and angiogenic properties. In this study, we aimed to enhance the antibacterial activity of SiO-CaO mesoporous bioactive glass nanoparticles (MBGN) by incorporating silver (Ag) through a surface modification approach. The modified Ag-containing nanoparticles (Ag-MBGN) maintained spherical shape, mesoporous structure, high dispersity, and apatite-forming ability after the surface functionalization. The antibacterial activity of Ag-MBGN was assessed firstly using a planktonic bacteria model. Moreover, a 3D tissue-engineered infected skin model was used for the first time to evaluate the antibacterial activity of Ag-MBGN at the usage dose of 1 mg/mL. In the planktonic bacteria model, Ag-MBGN exhibited a significant antibacterial effect against both Pseudomonas aeruginosa and Staphylococcus aureus in comparison to non-engineered (Ag-free) MBGN and the blank control. Moreover, Ag-MBGN did not show cytotoxicity towards fibroblasts at the usage dose. However, in the 3D infected skin model, Ag-MBGN only demonstrated antibacterial activity against S. aureus whereas their antibacterial action against P. aeruginosa was inhibited. In conclusion, surface modification by Ag incorporation is a feasible approach to enhance the antibacterial activity of MBGN without significantly impacting their morphology, polydispersity, and apatite-forming ability. The prepared Ag-MBGN are attractive building blocks for the development of 3D antibacterial scaffolds for tissue engineering.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2019.109764DOI Listing
October 2019

Porous microspheres support mesenchymal progenitor cell ingrowth and stimulate angiogenesis.

APL Bioeng 2018 Jun 26;2(2):026103. Epub 2018 Apr 26.

Department of Materials Science and Engineering, Insigneo Institute for in silico Medicine, The University of Sheffield, Sheffield S1 3JD, United Kingdom.

Porous microspheres have the potential for use as injectable bone fillers to obviate the need for open surgery. Successful bone fillers must be able to support vascularisation since tissue engineering scaffolds often cease functioning soon after implantation due to a failure to vascularise rapidly. Here, we test the angiogenic potential of a tissue engineered bone filler based on a photocurable acrylate-based high internal phase emulsion (HIPE). Highly porous microspheres were fabricated via two processes, which were compared. One was taken forward and investigated for its ability to support human mesenchymal progenitor cells and angiogenesis in a chorioallantoic membrane (CAM) assay. Porous microspheres with either a narrow or broad size distribution were prepared via a T-junction microfluidic device or by a controlled stirred-tank reactor of the HIPE water in oil in water (w/o/w), respectively. Culture of human embryonic stem cell-derived mesenchymal progenitor (hES-MP) cells showed proliferation over 11 days and formation of cell-microsphere aggregates. , hES-MP cells were found to migrate into microspheres through their surface pores over time. The presence of osteoblasts, differentiated from the hES-MP cells, was evidenced through the presence of collagen and calcium after 30 days. Microspheres pre-cultured with cells were implanted into CAM for 7 days and compared with control microspheres without pre-cultured cells. The hES-MP seeded microspheres supported greater angiogenesis, as measured by the number of blood vessels and bifurcations, while the empty scaffolds attracted host chick cell ingrowth. This investigation shows that controlled fabrication of porous microspheres has the potential to create an angiogenic, bone filling material for use as a cell delivery vehicle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5008556DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6481713PMC
June 2018

Selective laser melting-enabled electrospinning: Introducing complexity within electrospun membranes.

Proc Inst Mech Eng H 2017 Jun;231(6):565-574

Bioengineering and Health Technologies Group, The School of Clinical Dentistry, The University of Sheffield, Sheffield, UK.

Additive manufacturing technologies enable the creation of very precise and well-defined structures that can mimic hierarchical features of natural tissues. In this article, we describe the development of a manufacturing technology platform to produce innovative biodegradable membranes that are enhanced with controlled microenvironments produced via a combination of selective laser melting techniques and conventional electrospinning. This work underpins the manufacture of a new generation of biomaterial devices that have significant potential for use as both basic research tools and components of therapeutic implants. The membranes were successfully manufactured and a total of three microenvironment designs (niches) were chosen for thorough characterisation. Scanning electron microscopy analysis demonstrated differences in fibre diameters within different areas of the niche structures as well as differences in fibre density. We also showed the potential of using the microfabricated membranes for supporting mesenchymal stromal cell culture and proliferation. We demonstrated that mesenchymal stromal cells grow and populate the membranes penetrating within the niche-like structures. These findings demonstrate the creation of a very versatile tool that can be used in a variety of tissue regeneration applications including bone healing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0954411917690182DOI Listing
June 2017
-->