The development of an effective amphotericin B (AmB) topical formulation to replace the systemically toxic injections currently used in cutaneous leishmaniasis (CL) treatment is challenging due to poor absorption through the skin. Aiming at an effective local chemotherapy, we designed PLGA (poly(lactide-co-glycolide acid) microparticles loaded with deoxycholate amphotericin B (d-AmB) for both macrophage intracellular targeting and sustained extracellular release. For that, d-AmB/PLGA microparticles with sizes ranging from 0.5 μm to 20 μm were synthesized and tested both in vitro and in vivo. In vitro, d-AmB/PLGA was more selectively active against intracellular amastigotes of Leishmania amazonensis than free d-AmB (selectivity index = 50 and 25, respectively). In vivo, the efficacy of a single intralesional (i.l) injection with d-AmB/PLGA was determined in early and established BALB/c mouse ear lesions. In early lesions, a single injection given on day 10 of infection was more effective in controlling parasite growth than eight i.l. injections with free d-AmB, as measured on day 120. Such d-AmB/PLGA injection was also effective in established lesions (day 30), leading to 97% parasite burden reduction, as compared with d-AmB or liposomal AmB (Ambisome®) i.l. injection containing the same AmB dose. Pharmacokinetic studies showed that following d-AmB/PLGA injection, AmB leaked slower from non-infected than infected ears, yet remaining in the ear tissue for as long as 30 days. Of interest, AmB was not detectable in the circulating plasma for at least two weeks of d-AmB/PLGA injection, contrasting with the rapid and durable (2 days) detection after free d-AmB injection. Despite the transient ear swelling and local cell infiltration, no alterations in AST, ALT and creatinine serum levels was induced by d-AmB/PLGA. For its approved components, local efficacy, and single-dose applicability, this novel and safe AmB microparticle depot formulation has strong potential as a new therapy for human CL.

中文翻译：

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用可植入的两性霉素B负载微粒治疗皮肤利什曼病的新颖，安全的单剂量治疗。

由于皮肤吸收不良，开发有效的两性霉素B（AmB）局部制剂来替代目前在皮肤利什曼病（CL）治疗中使用的全身毒性注射剂具有挑战性。为了有效地进行局部化疗，我们设计了载有脱氧胆酸盐两性霉素B（d-AmB）的PLGA（聚丙交酯-乙交酯共聚物）微粒，用于巨噬细胞内靶向和持续胞外释放。为此，d-AmB / PLGA微粒合成和尺寸从0.5μm到20μm不等，并在体内外进行了测试。在体外，d-AmB / PLGA对亚马逊利什曼原虫的胞内变形虫的选择性比对游离d-AmB更具选择性（选择性指数分别为50和25）在体内，单个病变内的功效（i。l）在早期和确定的BALB / c小鼠耳部病变中确定注射d-AmB / PLGA。在早期病变中，如在第120天测得的，在感染的第10天进行单次注射比用自由d-AmB进行八次il注射更能有效地控制寄生虫的生长。这种d-AmB / PLGA注射对既定病变也有效（ （第30天），与含相同AmB剂量的d-AmB或脂质体AmB（Ambisome®）il注射相比，可减少97％的寄生虫负担。药代动力学研究表明，注射d-AmB / PLGA后，未感染的AmB泄漏的速度要慢于未感染的耳朵，但在耳朵组织中的停留时间长达30天。有趣的是，在至少两周的d-AmB / PLGA注射中，在循环血浆中未检测到AmB，与免费d-AmB注射后快速且持久（2天）检测相反。尽管短暂的耳部肿胀和局部细胞浸润，但d-AmB / PLGA并未诱导AST，ALT和肌酐血清水平的改变。由于其获批的成分，局部功效和单剂量适用性，这种新颖，安全的AmB微粒贮库制剂具有强大的潜力，可作为治疗人类CL的新疗法。