由于Se—Se键相对活泼, 对外部氧化和还原环境敏感, 双硒聚合物在药物控释系统有广泛的应用. 采用双硒二醇, 异佛尔酮二异氰酸酯和低分子壳聚糖为原料制备出了两亲性的双硒聚合物. 这种共聚物能够在水中发生自组装现象, 形成稳定的以PU为核, 壳聚糖为壳的球形纳米聚集体, 粒径约为130 nm. 并探索了该聚集体在氧化还原条件下的响应性, 发现不管在弱氧化还是弱还原环境下, 这种双硒聚合物都能发生Se—Se键断裂, 使得装载在聚集体中的正电荷药物盐酸阿霉素达到控制释放的效果.

Selenium has several unique biological effects in many aspects, making use of bioactive components and inorganic selenium to prepare antitumor organic selenium compounds will have a great significant impact on cancer therapy and patient wellbeing. It was well-known that Se—Se bond is very reactive and sensitive to the dual redox environment, therefore, we can take advantage of such feature to prepare diselenide-containing polymers which can be applied in the area of drug controlled release. In this paper, we prepared amphiphilic diselenide copolymers with diselenide-containing diols (HO-SeSe-OH), isophorone diisocyanate (IPDI), and water soluble low-molecular chitosan (LW-CS). The synthetic copolymers were characterized by means of gel permeation chromatography (GPC), ¹H NMR and FTIR spectroscopy. The molecular weight of CS-PUSeSe-CS copolymer was 4.42×10⁴ g/mol which calculated according to the integral ratio of the peaks at δ 4.00 and 4.42 which related to CH₂O groups of chitosan and NHCOOCH₂ groups of IPDI, respectively. The size distribution of aggregates measured by dynamic light scattering (DLS) measurements, which gave a result of about 130 nm in average diameter. The critical aggregate concentration (CAC) of aggregates was measured by the fluorescent probe method and the result was 0.01 mg/mL. The dual redox responsive of aggregates was studied both in VC and H₂O₂ solution, the results showed that amphiphilic diselenide copolymer would cause Se—Se chain scission in no matter weak oxidative or reductive ambient environment. Although negative charged drug-rhodamine B (RB) could not release out from aggregates due to electrostatic attraction. However, positive charged drug-doxorubicin hydrochloride (Doxo) can easily release from aggregates in reductive VC solution by analyzing UV-spectra at the wavelength of 500 nm, indicating aggregates assembled from diselenide-containing copolymers may act as powerful and efficient bionano reactors and realize controllable drug delivery by breaking Se—Se bonds.