Tabata Y, Uno K, Ikada Y, Muramatsu S
Research Center for Biomedical Engineering, Kyoto University, Japan.
J Pharm Pharmacol. 1993 Apr;45(4):303-8. doi: 10.1111/j.2042-7158.1993.tb05557.x.
A recombinant human tumour necrosis factor alpha (TNF) was conjugated to gelatin by means of carbodiimide to improve the in-vivo stability of TNF. About 55% of TNF activity was retained after gelatin conjugation as judged by the cytotoxicity assay using L-M cells in-vitro. Intraperitoneal injection of the TNF-gelatin conjugate significantly suppressed the in-vivo growth of murine Meth A fibrosarcoma cells (SS2 cells) in mouse peritoneum, in comparison with that of free TNF at the same dosage (P < 0.05). After intraperitoneal injection, TNF activity of the conjugate was detected in both the serum and the peritoneal cavity of mice for a longer period than was free TNF, irrespective of the presence of SS2 cells. Chromatographic studies of the conjugate demonstrated that the increase in the apparent molecular weight of TNF was consistent with gelatin conjugation. It is likely that this leads to a prolonged retention of TNF activity in-vivo. In addition, the TNF-gelatin conjugate suppressed the in-vitro growth of SS2 cells to the same extent as free TNF. Thus, it is possible that the longer retention period of the conjugate brought about an increase in the chance of contact between TNF and SS2 cells, resulting in the enhanced suppressive effect of TNF on in-vivo tumour cell growth. Gelatin conjugation is an effective method for increasing the in-vivo antitumour activity of TNF.
通过碳二亚胺将重组人肿瘤坏死因子α（TNF）与明胶偶联，以提高TNF在体内的稳定性。根据体外使用L-M细胞的细胞毒性试验判断，明胶偶联后约55%的TNF活性得以保留。与相同剂量的游离TNF相比，腹腔注射TNF-明胶偶联物可显著抑制小鼠腹膜内鼠Meth A纤维肉瘤细胞（SS2细胞）的体内生长（P < 0.05）。腹腔注射后，无论是否存在SS2细胞，偶联物的TNF活性在小鼠血清和腹腔中被检测到的时间都比游离TNF长。对偶联物的色谱研究表明，TNF表观分子量的增加与明胶偶联一致。这可能导致TNF活性在体内的保留时间延长。此外，TNF-明胶偶联物对SS2细胞体外生长的抑制程度与游离TNF相同。因此，偶联物保留时间延长可能增加了TNF与SS2细胞接触的机会，从而增强了TNF对体内肿瘤细胞生长的抑制作用。明胶偶联是提高TNF体内抗肿瘤活性的有效方法。
