Surface modification of biomaterials using plasma immersion ion implantation and deposition

Abstract

Although remarkable progress has been made on biomaterial research, the ideal biomaterial that satisfies all the technical requirements and biological functions is not available up to now. Surface modification seems to be a more economic and efficient way to adjust existing conventional biomaterials to meet the current and ever-evolving clinical needs. From an industrial perspective, plasma immersion ion implantation and deposition (PIII&D) is an attractive method for biomaterials owing to its capability of treating objects with irregular shapes, as well as the control of coating composition. It is well acknowledged that the physico-chemical characteristics of biomaterials are the decisive factors greatly affecting the biological responses of biomaterials including bioactivity, haemocompatibility and antibacterial activity. Here, we mainly review the recent advances in surface modification of biomaterials via PIII&D technology, especially titanium alloys and polymers used for orthopaedic, dental and cardiovascular implants. Moreover, the variations of biological performances depending on the physico-chemical properties of modified biomaterials will be discussed.

Keywords: antibacterial activity; bioactivity; haemocompatibility; physico-chemical characteristics; plasma immersion ion implantation and deposition; surface modification.

Figure 1.

Schematic of ion implantation and deposition processes.

Figure 2.

Schematic of the surface reaction (cross section of the Ca PIII-D sample shown). Adapted from Liu et al. [60] with permission.

Figure 3.

Interaction of fibrinogen with a solid via the charge transfer process.

Figure 4.

Surface morphology of the titanium surfaces after Ag-PIII examined by scanning electron microscopy: (a) control pure Ti; (b) 0.5 h-Ag-PIII; (c) 1.0 h-Ag-PIII; (d) 1.5 h-Ag-PIII. (e) X-ray diffraction pattern of control pure Ti surface, indexed as a-Ti with hexagonal close-packed structure. Size distributions of the particles on (f) 0.5 h-Ag-PIII. (g) 1.0 h-Ag-PIII and (h) 1.5 h-Ag-PIII. Adapted from Cao et al. [85] with permission.

Figure 5.

Illustration for the possible toxicity mechanism on the Ag nanoparticle (NP)-embedded surface. Adapted from Cao et al. [85] with permission.

Figure 6.

Atomic force microscopy photomicrographs. (a) The polyethylene terephthalate (PET) control and (b) PIII-PET films. Adapted from Wang et al. [89] with permission.