Hydroxyapatite/poly(ε-caprolactone) composite coatings on hydroxyapatite porous bone scaffold for drug delivery
Hydroxyapatite/poly(ε-caprolactone) composite coatings on hydroxyapatite porous bone scaffold for drug delivery
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DOI：
10.1016/j.biomaterials.2003.07.003
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发表时间：
2004-03-01
期刊：
影响因子：
14
通讯作者：
Kim, HE
中科院分区：
文献类型：
--
作者：
Kim, HW;Knowles, JC;Kim, HE
将羟基磷灰石（HA）和聚己内酯（PCL）复合材料涂覆在HA多孔支架上，并将抗生素药物盐酸四环素包埋在涂层中。通过聚合物网状方法获得的HA支架具有高孔隙率（接近87%）和可控的孔径（150-200 μ m）。由于其高的表面积和血液循环效率，这种发达的多孔结构有利于在药物递送系统中的使用。PCL聚合物作为涂层组分，用于改善HA支架的脆性和低强度，以及有效地捕获药物。为了提高涂层的骨传导性和生物活性，将HA粉末与PCL溶液杂化，制备HA-PCL复合涂层。通过改变涂层浓度和HA/PCL比例，研究了涂层的形貌、力学性能和生物降解性能。增加浓度使得茎更厚并且一些孔被堵塞;以及增加HA/PCL比使得涂层表面由于大量的HA颗粒而变得粗糙。然而，对于所有浓度和组成，均形成均匀的涂层，即，HA颗粒均匀地分散在PCL片中。复合涂层的加入使材料的抗压强度、弹性模量等力学性能提高了几个数量级。这些改善在较厚涂层的情况下更显著，而在HA/PCL比率的情况下观察到的差异很小。复合涂层在磷酸盐缓冲液中的体外生物降解率随培养时间线性增加，降解速率随涂层浓度和HA/PCL比例的增加而不同，随着涂层浓度和HA用量的增加，生物降解率增加。在短时间内（< 2 h），约20-30%的药物释放，特别是由于涂层表面的游离药物。然而，释放速率持续较长时间，并且高度依赖于涂层溶解的程度，这表明在具有HA + PCL涂层的多孔支架中控制药物释放的可能性。(C)2003 Elsevier Ltd.保留所有权利。
Hydroxyapatite (HA) porous scaffold was coated with HA and polycaprolactone (PCL) composites, and antibiotic drug tetracycline hydrochloride was entrapped within the coating layer. The HA scaffold obtained by a polymeric reticulate method, possessed high porosity (similar to87%) and controlled pore size (150-200 pm). Such a well-developed porous structure facilitated usage in a drug delivery system due to its high surface area and blood circulation efficiency. The PCL polymer, as a coating component, was used to improve the brittleness and low strength of the HA scaffold, as well to effectively entrap the drug. To improve the osteoconductivity and bioactivity of the coating layer, HA powder was hybridized with PCL solution to make the HA-PCL composite coating. With alteration in the coating concentration and HA/PCL ratio, the morphology, mechanical properties, and biodegradation behavior were investigated. Increasing the concentration rendered the stems thicker and some pores to be clogged; as well increasing the HA/PCL ratio made the coating surface be rough due to the large amount of HA particles. However, for all concentrations and compositions, uniform coatings were formed, i.e., with the HA particles being dispersed homogeneously in the PCL sheet. With the composite coating, the mechanical properties, such as compressive strength and elastic modulus were improved by several orders of magnitude. These improvements were more significant with thicker coatings, while little difference was observed with the HA/PCL ratio. The in vitro biodegradation of the composite coatings in the phosphate buffered saline solution increased linearly with incubation time and the rate differed with the coating concentration and the HA/PCL ratio; the higher concentration and HA amount caused the increased biodegradation. At short period (< 2 h), about 20-30% drug was released especially due to free drug at the coating surface. However, the release rate was sustained for prolonged periods and was highly dependent on the degree of coating dissolution, suggesting the possibility of a controlled drug release in the porous scaffold with HA + PCL coating. (C) 2003 Elsevier Ltd. All rights reserved.