| Summary: | 碩士 === 國立臺北科技大學 === 化學工程與生物科技系生化與生醫工程碩士班 === 107 === The main causes for failure of implants surgery are long exposure of implants or wounds and tissue ischemia. Besides, the bacterial infection caused by surrounding medical environment and equipment is also one of major risk for failure of surgery. It will greatly reduce the medical risk if we could creat a coating on implants surface for guide tissue growth and antibacteria.
Mesoporous bioactive glasses are mainly silicate and with good osteoinductivity. The mesoporous bioactive glasses have been used in medical dentistry and orthopedics for the past several decades. Strontium ion is a trace element in human bone, and previous studies have proposed it would promote osseointegration and angiogenesis. Silver ions can lead to bacterial apoptosis by bonding to the surface of cell membranes through surface charge imbalance. The bioactive glass containing strontium ions and silver ions will combine their advantages to achieve the multiple functions at the same time.
In this study, the polyelectrolyte multilayers (PEMs) coatings were prepared on 316L stainless steel to functionize the surface by spin-coating. The compostition of the multilayer films was made of biocompatible collagen as positively charged layer and biodegradable γ-poly glutamic acid as negatively charged layer; chitosan with a positively charged layer as the natural barrier; the bioactive glass incorporated with silver and strontium prepared by spray pyrolysis was added into the negatively charged layer. Though in vitro and in vivo tests, the PEMs coating would promote angiogenesis, osseointegration and antibacteria with the release of silver and strontium ions.
Herein, it is comfirmed that bioactive glass was successfully incorporated into the twenty layers polyelectrolyte multilayers. The PEMs coating had good hydrophilicity with a contact angle of 37.09 o; and hardness of 0.29 ± 0.09 GPa, Young’s modulus of 5.35 ± 1.55 GPa and roughness of 374.78±22.27 nm, as observed through nano-indention and white light interferometry. The PEMs coating was not only well antibacterial for one months, as seen in the inhibition zone test, but also biocompatible for rat bone marrow mesenchymal stem cells (rBMSCs) and human umbilical vein endothelial cells (HUVECs), as studied in the MTT assay. There were more hydroxyapatite depostitions on PEMs surface after being soaked by SBF, as invesgated by scanning electron microscope (SEM) and X-ray diffraction (XRD). Therefore, we believe that this technology will have great potential in surface modification of implants due to its antibacterial, angiogenesis, and osseointegration properties.
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