Enhanced biocompatibility of polyurethane-type shape memory polymers modified by plasma immersion ion implantation treatment and collagen coating: An in vivo study

Xinying Cheng; Jian Fei; Alexey Kondyurin; Kunkun Fu; Lin Ye; Marcela M M Bilek; Shisan Bao

doi:10.1016/j.msec.2019.02.032

Enhanced biocompatibility of polyurethane-type shape memory polymers modified by plasma immersion ion implantation treatment and collagen coating: An in vivo study

Mater Sci Eng C Mater Biol Appl. 2019 Jun:99:863-874. doi: 10.1016/j.msec.2019.02.032. Epub 2019 Feb 12.

Authors

Xinying Cheng¹, Jian Fei², Alexey Kondyurin³, Kunkun Fu⁴, Lin Ye⁵, Marcela M M Bilek⁶, Shisan Bao⁷

Affiliations

¹ Discipline of Pathology and School of Medical Sciences, Bosch Institute, Charles Perkins Centre, University of Sydney, NSW 2006, Australia; Centre for Advanced Materials Technology, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006, Australia.
² School of Life Science and Technology, Tongji University, Shanghai, China; Research Centre for Model Organisms, Shanghai, China.
³ Applied and Plasma Physics, School of Physics, University of Sydney, NSW 2006, Australia.
⁴ Centre for Advanced Materials Technology, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006, Australia; School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, China.
⁵ Centre for Advanced Materials Technology, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006, Australia.
⁶ Applied and Plasma Physics, School of Physics, University of Sydney, NSW 2006, Australia. Electronic address: marcela.bilek@sydney.edu.au.
⁷ Discipline of Pathology and School of Medical Sciences, Bosch Institute, Charles Perkins Centre, University of Sydney, NSW 2006, Australia; Tongren Hospital, Shanghai Jiaotong University School of Medicine, China. Electronic address: bob.bao@sydney.edu.au.

PMID: 30889761
DOI: 10.1016/j.msec.2019.02.032

Abstract

As one of the promising smart materials, polyurethane-type shape memory polymers (SMPU) have been extensively investigated as potential biomedical implant materials. However, the hydrophobicity and bio-inertness of SMPU are major problems for biomedical applications. We applied plasma immersion ion implantation (PIII) to increase surface wettability and enable one-step covalent, functionalisation of SMPU with biological molecules to create a tuneable, biocompatible surface. The changes of surface properties due to PIII treatment in nitrogen plasma were determined by measurements of morphology, contact angle, surface energy, and nanoindentation. Collagen attachment on SMPU with and without PIII treatment was measured by Attenuated total reflectance-Fourier transform infrared (ATR-FTIR). To investigate in vivo biocompatibility, SMPU with/without PIII and with/without collagen were subcutaneously implanted in mice. SMPU implants with surrounding tissue were collected at days 1, 3, 7, 14 and 28 to study acute/subacute inflammatory responses at histopathological and immunohistochemical levels. The results show that PIII treatment improves wettability and releases residual stress in the SMPU surfaces substantially. Covalent attachment of collagen on PIII treated SMPU in a single step incubation was demonstrated by its resistance to removal by rigorous Sodium Dodecyl Sulfonate (SDS) washing. The in-vivo results showed significantly lower acute/subacute inflammation in response to SMPU with PIII treatment + collagen coating compared to untreated SMPU, collagen coated untreated SMPU, and PIII treated SMPU, characterised by lower total cell numbers, macrophages, neovascularisation, cellular proliferation, cytokine production, and matrix metalloproteinase production. This comprehensive in vivo study of PIII treatment with protein coating demonstrates that the combination of PIII treatment and collagen coating is a promising approach to enhance the biocompatibility of SMPU, facilitating its application as an implantable biomaterial.

Keywords: Collagen; Host immune response; Inflammation; PIII; SMPU; Subcutaneous implantation.

MeSH terms

Animals
Cell Count
Cell Proliferation
Coated Materials, Biocompatible / chemistry*
Collagen / chemistry*
Cytokines / biosynthesis
Ki-67 Antigen / metabolism
Macrophages / cytology
Male
Materials Testing*
Matrix Metalloproteinases / metabolism
Mice
Nanoparticles / chemistry
Neovascularization, Physiologic
Plasma Gases / chemistry*
Polyurethanes / chemistry*
Rats
Wettability
von Willebrand Factor / metabolism

Substances

Coated Materials, Biocompatible
Cytokines
Ki-67 Antigen
Plasma Gases
Polyurethanes
von Willebrand Factor
Collagen
Matrix Metalloproteinases