The aim of this study was to fabricate Bacillus Calmette-Guérin (BCG)-loaded microneedle patches using micromould casting technique and compare their efficacy with the injectable counterparts. The microneedle patches were formulated using sodium alginate (10% w/v) and trehalose (20% of polymer). The patches were characterised using optical microscopy, scanning electron microscopy and folding endurance. Serum IgG, TLC, granulocyte count, lymphocyte count and CRP were assessed and results were compared to that of intradermal injections alongside controls. The results showed that polymeric patches had a thickness of 0.8 mm, microneedle projections of 272 ± 12 µm and folding endurance of more than 300. Based on haematological and IgG ELISA assays, microneedle-based BCG administration significantly activated the immune cells and induced production of lymphocytes, granulocytes and peptide-specific IgG in immunised rats that were comparable to injectable counterparts. There was an increase in IgG antibodies from 3 g/L to 5.98 g/L and an increase in leucocytes from 2.6 × 109/L to 18.45 × 109/L. There was also an increase in granulocytes from 14.4% to 29.15% and lymphocyte count from 58.75% to 85.3%. It was concluded that BCG-coated polymeric microneedle patches are suitable for the transdermal delivery of vaccine without inducing discomfort usually observed with injections.

中文翻译：

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装载 BCG 的聚合物微针的工程和表征。

本研究的目的是使用微模具铸造技术制造载有卡介苗 (BCG) 的微针贴片，并将其功效与可注射对应物进行比较。使用海藻酸钠 (10% w/v) 和海藻糖 (20% 的聚合物) 配制微针贴片。使用光学显微镜、扫描电子显微镜和耐折性对贴片进行了表征。评估了血清 IgG、TLC、粒细胞计数、淋巴细胞计数和 CRP，并将结果与​​皮内注射和对照进行了比较。结果表明，聚合物贴片的厚度为 0.8 mm，微针突出量为 272 ± 12 µm，折叠耐久度超过 300。基于血液学和 IgG ELISA 检测，基于微针的 BCG 给药显着激活免疫细胞并诱导免疫大鼠产生淋巴细胞、粒细胞和肽特异性 IgG，这与注射对应物相当。IgG 抗体从 3 g/L 增加到 5.98 g/L，白细胞从 2.6 × 109/L 增加到 18.45 × 109/L。粒细胞也从 14.4% 增加到 29.15%，淋巴细胞计数从 58.75% 增加到 85.3%。得出的结论是，BCG 涂层的聚合物微针贴片适用于疫苗的透皮递送，而不会引起通常在注射时观察到的不适。6 × 109/L 至 18.45 × 109/L。粒细胞也从 14.4% 增加到 29.15%，淋巴细胞计数从 58.75% 增加到 85.3%。得出的结论是，BCG 涂层的聚合物微针贴片适用于疫苗的透皮递送，而不会引起通常在注射时观察到的不适。6 × 109/L 至 18.45 × 109/L。粒细胞也从 14.4% 增加到 29.15%，淋巴细胞计数从 58.75% 增加到 85.3%。得出的结论是，BCG 涂层的聚合物微针贴片适用于疫苗的透皮递送，而不会引起通常在注射时观察到的不适。