Nanophase Ceramics as Bone Implant Coatings

描述(申请人提供)：拟议研究的总体目标是创造一种新的“智能”整形外科和牙科植入物涂层材料家族，在现有植入物的基础上增强新骨形成。为了选择性地增加骨细胞的功能，同时抑制竞争性细胞的功能，从而导致软组织而不是骨组织的形成，必须使用“智能”涂层材料。这种骨整合为原位种植体提供了机械稳定性，最大限度地减少了运动对周围组织的损伤，对于骨植入物的临床成功是必不可少的。通过这种方式，拟议的项目与健康相关的是增加植入物和并列骨骼之间的粘合力，以便接受关节或牙齿置换手术的患者可以迅速恢复正常的积极生活方式。此外，本提案旨在通过创造与并列的骨形成牢固、持久的粘结的材料来延长骨科材料的使用寿命。本研究提出的一种更有效的骨科植入涂层材料是：掺Y的纳米羟基磷灰石。纳米陶瓷由于具有直径小于100纳米的颗粒尺寸，正在成为耐人寻味的新材料配方。因此，纳米陶瓷模拟了骨骼的颗粒大小和形貌。掺Y涂层的羟基磷灰石可能会增加血清对钙的初始吸收，从而选择性地吸附蛋白质来增强骨细胞的功能。这是因为Y对钙有很高的亲和力。当不用作植入涂层时，先前的研究已经确定，掺Y的纳米相羟基磷灰石比现有的羟基磷灰石配方提高了骨细胞功能。本研究将在这些结果的基础上，使用一种新的技术在目前使用的骨假体材料(钛)上涂覆掺Y的纳米相羟基磷灰石。对于第一阶段的研究，掺入Y的钛涂层纳米相羟基磷灰石促进新骨合成和限制竞争细胞功能的能力将通过体外细胞模型来确定。具体地说，成骨细胞(骨形成细胞)和成纤维细胞(与竞争性软组织形成相关的细胞)的功能将在建议的涂层材料上确定。因此，这项提议的具体目标是将先前设计的促进新骨形成的材料与一种新技术相结合，将这些生物活性材料转化为实用的骨假体涂层。毫无疑问，这项拟议研究中用于研究新涂层技术和新涂层材料的设计标准可能会对开发具有更好的并列骨结合能力的下一代骨科植入物产生重大影响。

DESCRIPTION (provided by applicant): The overall objective of the proposed study is to create a new family of "smart" orthopedic and dental implant coating materials that enhance new bone formation over existing implants. "Smart" coating materials are necessary to selectively increase bone cell function while, at the same time, inhibit functions of competitive cells that lead to soft, instead of bony, tissue formation. Such osseointegration provides mechanical stability to an implant in situ, minimizes motion-induced damage to surrounding tissues, and is imperative for the clinical success of bone implants. In this manner, the health relatedness of the proposed project is to increase bonding between an implant and juxtaposed bone so that a patient who has received joint or dental replacement surgery may quickly return to a normal active lifestyle. Furthermore, the present proposal aims to increase the service-life of an orthopedic material by creating materials that form a strong, long lasting, bond with juxtaposed bone. The material proposed in the present study as a more effective orthopedic implant coating is: nanophase hydroxyapatite doped with yttrium. Nanophase ceramics are intriguing new material formulations since they possess grain sizes less than 100 nm in diameter. For this reason, nanophase ceramics simulate the grain size and topography of bone. Hydroxyapatite doped with yttrium coatings may increase initial absorption of calcium from serum leading to select protein adsorption to enhance bone cell function. This is speculated since yttrium has a high affinity for calcium. When not used as an implant coating, previous studies have determined that nanophase hydroxyapatite doped with yttrium increases bone cell function over existing hydroxyapatite formulations. The present study will build upon these results by using a novel technique to coat a currently utilized bone prosthetic material (titanium) with nanophase hydroxyapatite doped with yttrium. For Phase I studies, the ability of the titanium coated nanophase hydroxyapatite doped with yttrium to promote new bone synthesis and limit competitive cell function will be determined using in vitro cellular models. Specifically, osteoblast (bone-forming cells) and fibroblast (cells that have been associated with competitive soft tissue formation) function will be determined on the proposed coated materials. The specific aims of this proposal are therefore to combine previously designed materials that enhance new bone formation with a novel technique that will transform these bioactive materials into a practical bone prosthetic coating. Undoubtedly, design criteria used in the proposed study to investigate new coating techniques coupled with a new coating material could have great impact in the development of the "next-generation" of orthopedic implants with an improved ability to bind to juxtaposed bone.