目前臨床上針對皮下膿腫 (subcutaneous abscesses) 等細菌性感染，大多是採取投遞抗生素以及清創等治療方法。然而，大量具有抗藥性的細菌產生以及清創過程對病人帶來的痛苦，使現有治療方式逐漸遇到了瓶頸。鑑此，開發新一代的抗菌系統逐漸成為學術界及臨床上的熱門議題。本研究利用單乳化法開發出一個內部載有靛氰綠 (ICG) 且表面修飾了乙二醇幾丁聚醣 (glycol chitosan) 的奈米材料，透過乙二醇幾丁聚醣的pH應答性讓載體針對細菌產生電荷性吸附並形成聚集，減少對周圍組織的影響，再利用近紅外光 (NIR) 的照射，使ICG產生光熱效應來產生抑菌效果。從物化性分析來看，此載體具有良好穩定性、生物相容性、pH應答性及聚菌能力，能夠在NIR照射5分鐘後就升到50℃的殺菌溫度；胞外實驗部分則是透過革蘭氏陰性菌大腸桿菌 (Escherichia coli) 和革蘭氏陽性菌枯草桿菌 (Bacillus subtilis) 來測試載體對於細菌感染的治療效果，結果證實此載體能在細菌周圍產生局部高熱 (local hyperthermia)，和單純的整體加熱方法相比其殺菌效率更為顯著，顯示此系統具有應用於臨床上的高度潛能。

Subcutaneous abscesses are focal bacterial infections that are often accompanied with the acidified microenvironment (pH 6-6.6). Two common applied therapies for the abscess management are incision-drainage and systemic administration of antibiotics. However, incision-drainage is a laborious and painful process for patients. Additionally, systemic antibiotic treatment is often accompanied by the evolution of bacterial antibiotic resistance. Therefore, it is an unmet need to develop a reliable antibacterial system to deal with the infections caused by antibiotic-resistant pathogens. The present study reports a system of glycol chitosan-modified, indocyanine green-loaded PLGA nanoparticles (GIP-NPs). According to the physicochemical analysis, this system demonstrates good results in photothermal effect, biocompatibility, pH-response and shelf life. Upon encountering of the acidic environment, GIP-NPs undergo a surface-charge conversion and induce the bacteria-specific aggregation without absorption to the surrounding normal cells. After near-infrared (NIR) irradiation, GIP-NPs can generate local hyperthermia and cause irreversible damage to bacteria. It also shows higher antibacterial effect compared with simply increasing bulk temperature. These experimental results reveal the strong potential of GIP-NPs for the antibacterial therapy in the next generation.

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