Roberts Justin, Bingham Josh, McLaren Alex C, McLemore Ryan
Orthopaedic Department, Banner Good Samaritan Medical Center, 1320 N 10th Street, Phoenix, AZ, 85006, USA.
Clin Orthop Relat Res. 2015 Jul;473(7):2262-9. doi: 10.1007/s11999-015-4232-y.
Liposomal amphotericin B is locally delivered to treat fungal orthopaedic infections but little is known about local tissue toxicity, if any, that might be associated with local delivery.
QUESTIONS/PURPOSES: (1) Is liposomal amphotericin B cytotoxic in vitro? (2) Is locally delivered liposomal amphotericin B toxic to tissue in vivo?
Mouse fibroblasts (BA LB/3T3 A31) and osteoblasts (MC3T3) were exposed to two formulations of amphotericin B (liposomal and deoxycholate) at concentrations of 0, 1, 5, 10, 100, 500, and 1000 μg/mL. Cell viability was determined by MTT assay after 1, 3, and 5 hours of exposure and a proliferation assay after 1, 4, and 7 days of exposure and then after 3 recovery days without drug. Tissue exposure occurred by local delivery of liposomal amphotericin B, 200 or 800 mg/batch antifungal-loaded bone cement (ALBC), or amphotericin B deoxycholate, 800 mg/batch ALBC in rat paraspinal muscles. White blood cell count (WBC) and serum amphotericin B levels were obtained on Days 1 and 3. Rats were euthanized at 2 and 4 weeks and semiqualitative histopathology was performed.
Liposomal amphotericin B is cytotoxic in vitro but not toxic to tissues in vivo. All cells survived concentrations up to 1000 μg/mL for 5 hours, 100% ± 0%, but none survived ≥ 100 μg/mL for 7 days, 0% ± 0%. Fibrosis was seen adjacent to ALBC without inflammation or necrosis, indistinguishable from controls for both liposomal amphotericin B doses. Amphotericin B serum levels were all less than 1 µg/mL and WBC counts were all normal.
In vitro cytotoxicity to liposomal amphotericin B occurred but no adverse tissue reaction was seen in vivo.
Local delivery of liposomal amphotericin B in ALBC was well tolerated by mouse tissue; however, clinical studies are needed to confirm this finding in humans.
脂质体两性霉素B通过局部给药治疗骨科真菌感染，但对于局部给药可能相关的局部组织毒性（若存在）知之甚少。
问题/目的：（1）脂质体两性霉素B在体外是否具有细胞毒性？（2）局部给药的脂质体两性霉素B在体内对组织是否有毒性？
将小鼠成纤维细胞（BA LB/3T3 A31）和成骨细胞（MC3T3）暴露于两种两性霉素B制剂（脂质体和脱氧胆酸盐），浓度分别为0、1、5、10、100、500和1000μg/mL。在暴露1、3和5小时后通过MTT法测定细胞活力，在暴露1、4和7天后以及在无药物的3天恢复后通过增殖试验测定细胞活力。通过在大鼠椎旁肌局部递送脂质体两性霉素B、每批200或800mg载有抗真菌药物的骨水泥（ALBC）或每批800mg脱氧胆酸盐两性霉素B的ALBC来进行组织暴露。在第1天和第3天获取白细胞计数（WBC）和血清两性霉素B水平。在2周和4周时对大鼠实施安乐死并进行半定性组织病理学检查。
脂质体两性霉素B在体外具有细胞毒性，但在体内对组织无毒。所有细胞在浓度高达1000μg/mL的情况下暴露5小时后均存活，存活率为100%±0%，但在浓度≥100μg/mL的情况下暴露7天后均无存活，存活率为0%±0%。在ALBC附近可见纤维化，无炎症或坏死，两种脂质体两性霉素B剂量的情况与对照组无差异。两性霉素B血清水平均低于1μg/mL，白细胞计数均正常。
脂质体两性霉素B在体外具有细胞毒性，但在体内未见不良组织反应。临床相关性：小鼠组织对脂质体两性霉素B在ALBC中的局部给药耐受性良好；然而，需要进行临床研究以在人体中证实这一发现。
