Design of Hyaluronic Acids Hydrogels as a Long-term Implant and Those Application for Endometriosis Therapy

子宫内膜异位症是一种由痛经、性交疼痛和发育不全引起的疾病。根据大量的流行病学调查，认为育龄妇女感染子宫内膜异位症的比例为5-10%。这种疾病常在卵巢内形成囊肿。口服和皮下注射达那唑和促性腺激素释放激素类似物已被尝试治疗子宫内膜异位症。然而，这些药物会导致肝功能障碍、发育不全、浮肿、头痛等不良反应。从这个角度来看，子宫局部释放达那唑有望改善副作用。在这里，我们报告了用于注射水凝胶的疏水改性透明质酸(HA)和达那唑的局部释放。HA在子宫中的生物可降解性可能导致达那唑的受控释放，而不会引起炎症。合成了硬脂酰羟基磷灰石和戊二酰羟基磷灰石，并考察了它们在…中的载药量、酶降解、释放以及对模型大鼠的影响加入100U/ml透明质酸酶(HAase)160min后，HAase的存在无明显变化。在相同条件下，加入HAase后，GlHA和HA的粘度分别在161和120min降至初始值的50%。这些结果表明，硬脂酰基和戊二酸基对HA的化学修饰抑制了HA酶对HA主干的可及性。特别是，较长的StHA烷基链可以有效地抑制HAase对HA主干的可及性。引入的疏水基团有助于提高达那唑的溶解度。由于其取代度较高，GlHA似乎具有更多的疏水结构域。在两个系统中，达那唑在整个实验期内的血药浓度均在10hg/ml以下。这一数值低于口服达那唑血药浓度的1/20。还测量了达那唑在包囊中的浓度。在StHA和GlHA系统中，包囊中的达那唑浓度约为10μg/g(第1周)。在第2周时，StHA系统降至1μg/g，而GlHA系统仍为8μg/g。这些结果表明，到第2周时，StHA系统中的达那唑几乎全部从包囊中消失。上述结果提示，突释达那唑可使包囊中的达那唑浓度增加1周。另一方面，StHA体系中第2周的低浓度可能是由于Danazol的缓慢释放所致，StHA的降解速度慢于GlHA。通过显微图像观察局部注射达那唑增溶的StHA系统对包囊的影响。注射后第4周可见整体细胞萎缩，但未注射时未见细胞萎缩。考虑到达那唑在血浆和包囊中的浓度，释放的达那唑在包囊中被直接吸收，而不抑制下丘脑-垂体功能。较少

Endometriosis is a disease caused by algomenorrhea, coital pain, and agenesis. According to a lot of epidemiological surveys, it is thought that 5-10% of reproductive-age women infected the endometriosis. This disease often forms cysts in ovary. Oral administration and hypodermic injection of danazol and GnRH analogues have been tried to cure the endometriosis. However, those drugs cause adverse effects such as liver dysfunction, agenesis, dropsy, headache, and so on. From this perspective, local release of danazol at uterus is expected to improve the side effects. Here, we report on hydrophobically modified hyalumnic acid (HA) for injectable hydrogels and local release of danazol. Biodegradable properties of HA at uterus may lead to controlled release of danazol without causing inflammations. Stearoyl HA (StHA) and glutaryl HA (GlHA) were synthesized and evaluated in terms of danazol loading, enzymatic degradation, danazol release, and those effects on a model rat.Viscosity of StHA in … More the presence of 100 unit/ml hyaluronidase (HAase) was not changed at 160 min after adding the HAase. Viscosities of GlHA and HA under the same condition were decreased to 50 % of the initial value at 161 and 120 min after adding the HAase, respectively. These results suggest that chemical modification of HA by stearoyl and glutaryl groups suppressed the accessibility of HAase to the HA backbone. Especially, longer alkyl chains of StHA was effective for suppressing the accessibility of HAase to the HA backbone. The introduced hydrophobic groups contribute to the increased solubility of danazol. GlHA seemed to be more hydrophobic domains because of its high DS. In both systems, the concentration of danazol in plasma was below 10 hg/ml through the experimental period. This value is below 1/20 of the concentration of danazol in plasma via oral administration.Concentration of danazol in the cysts was also measured. In both StHA and GlHA systems, the concentrations of danazol in the cysts are about 10 μg/g(at 1st week). At 2 nd week, it decreased to 1μg/g in the StHA system, while it remained 8 μg/g in the GlHA system. These results indicate that almost all the danazol in the StHA system was disappeared from cysts by the 2 nd week. From these results, it is suggested that burst release of danazol increased the concentration of danazol in cysts by the 1 st week. On the other hand, the low concentration at 2 nd week in StHA system is presumably due to slow release of danazol in relation to slower degradation of StHA than that of GlHA. The effect of local injecting the danazol solubilized StHA system on cysts was observed by microscopic image. Atrophy of whole cells was observed after injecting at 4 th weeks, although such an atrophy of cells without injection was not observed. Taking the result of danazol concentration in plasma and cysts into account, the released danazol was absorbed directly in cysts without inhibiting hypothalamo-hypophysial functions. Less