Abstract

Purpose

Due to the favorable physicochemical properties and the biocompatibility, carbon dots (CDs) have gained a great attention as a tumor targeting agent. This study investigates polyethylenimine capped CDs (PEI capped CDs) as a prospective nanocarrier of technetium-99m (^99mTc) for tumor targeting. Technetium-labeled CDs could be introduced as a promising candidate for single photon emission tomography (SPECT) imaging.

Materials and methods

Polyethylenimine capped CDs were prepared by hydrothermal method using hyperbranched PEI and citric acid. For a purpose of comparison, citrate capped CDs were also prepared by microwave irradiation. Both types of CDs were characterized and radiolabeled with ^99mTc using sodium borohydride (NaBH₄) as a reducing agent. Biodistribution and tumor targeting efficiency of the produced radiolabeled CDs have been studied in Earlich ascites tumor mice model.

Results

Citrate capped CDs and PEI capped CDs have been synthesized successfully and characterized. High radiochemical yield of ^99mTc-citrate capped CDs ^99mTc-PEI capped CDs was obtained (97 ± 0.7 and 90 ± 0.2, respectively). Biodistribution studies of ^99mTc-labeled PEI capped CDs have shown a potential tumor uptake (10 ± 0.5% Radioactivity/gram tumor) with high target to non-target ratio (T/NT) around 7 at 1-h post injection. ^99mTc-citrate capped CDs have achieved a lower tumor uptake level (3.8 ± 0.3% Radioactivity/gram tumor 1 h post injection).

Conclusion

This study introduces PEI capped CDs as a promising nanocarrier of ^99mTc for efficient tumor targeting. Technetium-labeled PEI capped CDs could be utilized as a potential SPECT tumor imaging agent.

中文翻译：

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用于肿瘤靶向的聚乙烯亚胺封端碳点的 99mTc 放射性标记：合成、表征和生物分布

摘要

目的

由于良好的理化性质和生物相容性，碳点（CD）作为肿瘤靶向剂受到了极大的关注。本研究调查了聚乙烯亚胺封端的 CD（PEI 封端的 CD）作为用于肿瘤靶向的锝-99m ( ^99m Tc)的前瞻性纳米载体。锝标记的 CD 可以作为单光子发射断层扫描 (SPECT) 成像的有希望的候选者引入。

材料和方法

使用超支化 PEI 和柠檬酸通过水热法制备聚乙烯亚胺封端的 CD。为了进行比较，还通过微波辐射制备了柠檬酸盐封端的 CD。使用硼氢化钠 (NaBH ₄ ) 作为还原剂对两种类型的 CD 进行表征并用^99m Tc 进行放射性标记。已在 Earlich 腹水肿瘤小鼠模型中研究了所产生的放射性标记 CD 的生物分布和肿瘤靶向效率。

结果

柠檬酸盐封端的 CDs 和 PEI 封端的 CDs 已被成功合成和表征。的高的放射化学产^99米锝-柠檬酸盐封端的CD ^99米获得（97±分别为0.7和90±0.2，）的Tc-PEI封端的CD。^99m Tc 标记的 PEI 加帽 CD 的生物分布研究表明，在注射后 1 小时内，潜在的肿瘤吸收（10 ± 0.5% 放射性/克肿瘤）具有高靶标与非靶标比 (T/NT) 约 7。^99m Tc-柠檬酸盐封顶的 CD 已达到较低的肿瘤摄取水平（注射后 1 小时为 3.8 ± 0.3% 放射性/克肿瘤）。

结论

这项研究将 PEI 加帽的 CD 作为一种有前途的^99m Tc纳米载体，用于有效的肿瘤靶向。锝标记的 PEI 加帽 CD 可用作潜在的 SPECT 肿瘤成像剂。