The influence of animal species, gender and tissue on the structural, biophysical, biochemical and biological properties of collagen sponges

peer-reviewedAlthough collagen type I is extensively used in biomedicine, no study to-date has assessed how the properties of the produced scaffolds are affected as a function of species, gender and tissue from which the collagen was extracted. Herein, we extracted and characterised collagen from porcine and bovine, male and female and skin and tendon tissues and we subsequently fabricated and assessed the structural, biophysical, biochemical and biological properties of collagen sponges. All collagen preparations were of similar purity and free-amine content (p > 0.05). In general, the porcine groups yielded more collagen; had higher (p < 0.05) denaturation temperature and resistance to enzymatic degradation; and lower (p < 0.05) swelling ratio and compression stress and modulus than the bovine groups of the same gender and tissue. All collagen preparations supported growth of human dermal fibroblasts and exhibited similar biological response to human THP-1 monocytes. These results further illustrate the need for standardisation of collagen preparations for the development of reproducible collagen-based devices

Non-destructive determination of collagen fibril width in extruded collagen fibres by piezoresponse force microscopy

Extruded collagen fibres are a promising platform for tissue engineering applications. Ensuring that the functional properties of the engineered tissues possess similar structural properties as native tissues is important for biomedical applications. Advanced imaging tools including scanning electron microscopy (SEM) and atomic force microscopy (AFM) have revealed the structural features of collagen fibrils within such fibres; however, these techniques often require modification steps that can alter the sample in the process. Here, lateral piezoresponse force microscopy (LPFM), which is sensitive to the polar orientation of piezoelectric collagen fibrils, is demonstrated as a promising tool to assess the width of individual fibrils and moreover map their organisation and polar orientation without altering the sample. Within the fibres studied, the collagen fibrils showed a highly anisotropic arrangement with preferred alignment along the length of the fibre. Fibril widths of 74 ± 18 nm and 73 ± 19 nm in untreated and bleached fibres, respectively, were measured from LPFM amplitude images. These values agreed with values from SEM (70 ± 10 nm) and AFM (71 ± 19 nm) measurements that could only be obtained from bleached fibres.Department of Agriculture, Food and the MarineEuropean Commission Horizon 2020Science Foundation IrelandTeagascMinistry of Higher Education of Saudi Arabi

The collagen suprafamily: From biosynthesis to advanced biomaterial development

Collagen is the oldest and most abundant extracellular matrix protein that has found many applications in food, cosmetic, pharmaceutical, and biomedical industries. First, an overview of the family of collagens and their respective structures, conformation, and biosynthesis is provided. The advances and shortfalls of various collagen preparations (e.g., mammalian/marine extracted collagen, cell-produced collagens, recombinant collagens, and collagen-like peptides) and crosslinking technologies (e.g., chemical, physical, and biological) are then critically discussed. Subsequently, an array of structural, thermal, mechanical, biochemical, and biological assays is examined, which are developed to analyze and characterize collagenous structures. Lastly, a comprehensive review is provided on how advances in engineering, chemistry, and biology have enabled the development of bioactive, 3D structures (e.g., tissue grafts, biomaterials, cell-assembled tissue equivalents) that closely imitate native supramolecular assemblies and have the capacity to deliver in a localized and sustained manner viable cell populations and/or bioactive/therapeutic molecules. Clearly, collagens have a long history in both evolution and biotechnology and continue to offer both challenges and exciting opportunities in regenerative medicine as nature\u27s biomaterial of choice.This work forms part of the Teagasc Walsh Fellowship (grant award number: 2014045) and the ReValueProtein Research Project (grant award number: 11/F/043) supported by the Department of Agriculture, Food and the Marine (DAFM) under the National Development Plan 2007–2013 funded by the Irish Government. This work has also been supported from the: Health Research Board, Health Research Awards Programme (grant agreement number: HRA_POR/2011/84); Science Foundation Ireland, Career Development Award Programme (grant agreement number: 15/CDA/3629); Science Foundation Ireland and the European Regional Development Fund (grant agreement number: 13/RC/2073); College of Engineering and Informatics, National University of Ireland Galway; EU FP7/2007-2013, NMP award, Green Nano Mesh Project (grant agreement number: 263289); EU FP7/2007-2013, Health award, Neurograft Project (grant agreement number: 304936); EU H2020, ITN award, Tendon Therapy Train Project (grant agreement number: 676338); National University of Singapore Tissue Engineering Programme (NUSTEP). The authors would like to thank M Doczyk, E Collin, W Daly, M Abu-Rub, D Thomas, S Browne, C Tapeinos, A Satyam and D Cigognini for their help in producing the figures. A.S., L.M.D., Z.W., N.S., A.K., R.N.R., A.M.M., A.P., M.R., and D.I.Z. have no competing interests. Y.B. is an employee of Sofradim Production – A Medtronic Company. D.I.Z would like to dedicate the manuscript to A.G.Z. who left and A.D.Z. who cam