School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, Paschim Medinipur, West Bengal, India.
Adv Exp Med Biol. 2020;1251:1-17. doi: 10.1007/5584_2019_447.
Titanium implants are considered the gold standard of treatment for dental and orthopedic applications. Biocompatibility, low elasticity, and corrosion resistance are some of the key properties of these metallic implants. Nonetheless, a long-term clinical failure of implants may occur due to inadequate osseointegration. Poor osseointegration induces mobility, inflammation, increased bone resorption, and osteolysis; hence, it may result in painful revision surgeries. Topographical modifications, improvement in hydrophilicity, and the development of controlled-release drug-loading systems have shown to improve cellular adhesion, proliferation, and differentiation. Surface modifications, along with drug coating, undoubtedly demonstrate better osseointegration, especially in challenged degenerative conditions, such as osteoporosis, osteoarthritis, and osteogenesis imperfecta. Anabolic bone-acting drugs, such as parathyroid hormone peptides, simvastatin, prostaglandin-EP4-receptor antagonist, vitamin D, strontium ranelate, and anti-catabolic bone-acting drugs, such as calcitonin, bisphosphonates, and selective estrogen receptor modulators, expedite the process of osseointegration. In addition, various proteins, peptides, and growth factors may accessorize the idea of localized therapy. Loading these substances on modified titanium surfaces is achieved commonly by mechanisms such as direct coating, adsorption, and incorporating in biodegradable polymers. The primary approach toward the optimum drug loading is a critical trade-off between factors preventing release of a drug immediately and those allowing slow and sustained release. Recent advances broaden the understanding of the efficacy of adsorption, hydrogel coating, and electrospinning layer-by-layer coating facilitated by differential charge on metallic surface. This review discusses the existing approaches and challenges for the development of stable and sustained drug delivery systems on titanium implants, which would promote faster and superior osseointegration.
钛植入物被认为是治疗口腔和骨科应用的金标准。生物相容性、低弹性和耐腐蚀性是这些金属植入物的一些关键特性。尽管如此，由于骨整合不足，植入物的长期临床失败仍可能发生。骨整合不良会导致移动、炎症、骨吸收增加和骨溶解；因此，可能导致疼痛的翻修手术。形貌修饰、亲水性改善和控释载药系统的开发已被证明可改善细胞黏附、增殖和分化。表面修饰和药物涂层无疑可提高骨整合，特别是在骨质疏松症、骨关节炎和成骨不全等具有挑战性的退行性疾病中。甲状旁腺激素肽、辛伐他汀、前列腺素 E1 受体拮抗剂、维生素 D、雷奈酸锶和抗分解代谢骨作用药物等促骨合成药物可加速骨整合过程。此外，各种蛋白质、肽和生长因子可辅助局部治疗的理念。通常通过直接涂层、吸附和掺入可生物降解聚合物等机制将这些物质加载到改性钛表面上。最佳药物负载的主要方法是在防止药物立即释放的因素和允许缓慢持续释放的因素之间进行关键的权衡。最近的进展拓宽了对金属表面差分电荷促进的吸附、水凝胶涂层和电纺层层涂层的疗效的理解。这篇综述讨论了在钛植入物上开发稳定和持续药物输送系统的现有方法和挑战，这将促进更快和更好的骨整合。
