Silver Nanoparticles and Growth Factors Incorporated Hydroxyapatite Coatings on Metallic Implant Surfaces for Enhancement of Osteoinductivity and Antibacterial Properties

Abstract

Research on incorporation of both growth factors and silver (Ag) into hydroxyapatite (HA) coatings on metallic implant surfaces for enhancing osteoinductivity and antibacterial properties is a challenging work. Generally, Ag nanoparticles are easy to agglomerate and lead to a large increase in local Ag concentration, which could potentially affect cell activity. On the other hand, growth factors immobilization requires mild processing conditions so as to maintain their activities. In this study, bone morphology protein-2 (BMP-2) and Ag nanoparticle contained HA coatings were prepared on Ti surfaces by combining electrochemical deposition (ED) of Ag and electrostatic immobilization of BMP-2. During the ED process, chitosan (CS) was selected as the stabilizing agent to chelate Ag ions and generate Ag nanoparticles that are uniformly distributed in the coatings. CS also reduces Ag toxicity while retaining its antibacterial activity. Afterwards, a BMP/heparin solution was absorbed on the CS/Ag/HA coatings. Consequently, BMP-2 was immobilized on the coatings by the electrostatic attraction between CS, heparin, and BMP-2. Sustained release of BMP-2 and Ag ions from HA coatings was successfully demonstrated for a long period. Results of antibacterial tests indicate that the CS/Ag/HA coatings have high antibacterial properties against both Staphylococcus epidermidis and Escherichia coli. Osteoblasts (OB) culture reveals that the CS/Ag/HA coatings exhibit good biocompatibility. Bone marrow stromal cells (BMSCs) culture indicates that the BMP/CS/Ag/HA coatings have good osteoinductivity and promote the differentiation of BMSCs. Ti bars with BMP/CS/Ag/HA coatings were implanted into the femur of rabbits to evaluate the osteoinductivity of the coatings. Results indicate that BMP/CS/Ag/HA coatings favor bone formation in vivo. In summary, this study presents a convenient and effective method for the incorporation of growth factors and antibacterial agents into HA coatings. This method can be utilized to modify a variety of metallic implant surfaces.

Innovative biodegradable poly(L-lactide)/collagen/<br />hydroxyapatite composite fibrous scaffolds promote osteoblastic proliferation and differentiation

“…However, the cell viability at day 7 was higher than that at days 1 and 3. After cells were cultured on PLLA, PLLA/HA, PLLA/Coll, and PLLA/ Coll/HA for 7 days, cell viability was increased to 105.5%, 111.1%, 114.4%, and 112.6%, respectively, compared to Wavenumber (cm -1 ) Strain (%) 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 …”

“…2 Titanium alloy, as a bone substitute material, requires reoperation to remove it from the injured part due to difficulty in the degradation process and is usually associated with pain. 3,4 Therefore, it is necessary to develop a biocompatible material for use in bone regeneration. The scaffold materials are usually used as an initial structure supporting cell growth and phenotype maintenance in bone restoration.…”

Multifunctional biomaterial coatings: synthetic challenges and biological activity

“…Sustained release of silver and BMP-2 mediated antibacterial properties as well as osteogenic differentiation of bone marrow stem cells. These in vitro results could be emphasized by in vivo studies showing favored bone formation by coating titanium with the described multifunctional construct (Xie et al, 2014). A BMP-2/heparin complex was also used in the study summarized in Table 3, line m. Notably, Lee and co-workers immobilized heparin via the strong DOPA-titanium interaction ( Figure 5A).…”

Nanostructured Architectures by Assembling Polysaccharide‐Coated BSA Nanoparticles for Biomedical Application

“…Various cationic polymer coatings have been used to coat on negative charged BNP, such as poly-L -lysine, [ 21 ] polyethylenimine (PEI) [ 7a ] and poly(allylamine hydrochloride) (PAH)/sodium poly(4-styrene sulfonate) (PSS). [ 23 ] In this study, CHI is used to coat on BNP surfaces, which is a polycationic polymer with excellent biocompatibility and admirable biodegradability. [ 24 ] The primary amines in the CHI backbone can bind to negatively charged BNPs via an electrostatic interaction and lead to the spontaneous formation of nano-thick fi lms on the BNPs surfaces, [ 25 ] which improve the stability of BNPs (Figure 2 ) and realize the sustained release of BMP-2 and Van for a long term (Figure 2 b).…”