臨床上，過量活性氧化物質(Reactive Oxygen Species, ROS)的產生是促進許多炎症疾病進展的關鍵因素，例如骨關節炎等。氫氣(Hydrogen gas, H2)被視為是一種新的醫學氣體，對細胞和器官具有抗氧化、抗發炎和抗凋亡等保護作用，其最大優點為在體內的施用安全性高且無明顯的副作用。目前給予H2的方式主要有直接吸入含有H2的混合氣體、飲用飽和氫水及透過靜脈或腹腔注射含有H2的生理食鹽水等，而在常溫常壓下H2在水中的溶解度很低且其具有容易逸散的特性，導致這些給予方式在病灶處在短時間內不易有效地累積H2濃度，須長期給予H2。在本研究裡，我們將鎂粉包覆於具疏水性的聚乳酸-甘醇酸(poly lactic-co-glycolic acid, PLGA)載體載體內，以原位注射方式將此微球注射至小鼠的骨關節炎處，藉由發炎處所產生的組織液滲透至微球內部後，與鎂粉進行反應產生H2，除了可以保護因鎂粉造成的組織傷害，也可視為一氫氣緩釋系統，其產氫時間可以延長至3天，且產生的H2可以藉由擴散進入組織和細胞中，於病灶處達到有效的治療濃度，進而清除病灶處所產生的ROS，以達到治療骨關節發炎的效果。

Inflammation is associated with numerous diseases including osteoarthritis, which is featured by the overproduction of reactive oxygen species (ROS). Hydrogen (H2) has been reported to have the capability to reduce oxidative stress by selectively scavenging hydroxyl radical (•OH) with no apparent side effects and can thus be served as a therapeutic medical gas for the treatment of inflammatory diseases. Administration of H2-gas (via inhalation with air), H2-water (via oral intake) or H2-saline (via intravenous drip infusion), has been shown promising in treating several inflammatory diseases in animal models. However, the amount of H2 absorbed by the body systematically through these methods may not enough to scavenge the ROS generated in inflamed tissues, because the solubility of H2 in the biological environment is low. To dissolve this problem, a poly lactic-co-glycolic acid (PLGA) microparticle system containing magnesium powders (Mg@PLGA MPs) that can generate H2 gas in a sustained manner is proposed herein. The feasibility of using the as-prepared Mg@PLGA MPs to scavenge ROS, thus improving local inflammation, is studied in a mouse model with experimentally created osteoarthritis, via local injection.

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