Narrow Results

Porphyrins and phthalocyanines are photosensitizers (PS) that are used in clinical imaging, detection of cancer cells and are particularly applied in photodynamic therapy (PDT). Many scientists have been focused on the design of different porphyrin compounds. However, similar to other anti-cancer agents, they cannot selectively recognize tumor tissues. Scientists are seeking new methods to overcome this problem and to find appropriate targeted delivery strategies. Plant lectins are especially suitable molecules for such targeting as they preferentially recognize specific antigens on the glycosylated cancer cells. This review will give more detailed information about the dual function of lectins and their interactions with PSs, which is a new perspective in targeted PDT. The implications and potential applications of such studies will also be discussed.

Although photodynamic therapy has been extensively studied in recent years and preclinical studies have shown promising results, strategies for enhancing PDT outcomes and reducing side effects still urgently need to be developed. In this study, a series of Tamoxifen-zinc(II) phthalocyanine conjugates have been designed and synthesized. In these “double-headed” conjugates, photodynamic therapy agent zinc(II) phthalocyanine and hormone therapy drug Tamoxifen were combined via oligoethylene glycol linkers. The conjugates show high specificity, and some of them show cytotoxic effects against the MCF-7 cells overexpressed Estrogen receptor, due to the targeting and cytostatic Tamoxifen moiety. Upon illumination, all these conjugates show high cytotoxicity due to the photosensitizing phthalocyanine unit. Their structure-activity relationship was also assessed. The results show that $\alpha$-substituted Tamoxifen-zinc(II) phthalocyanine conjugates are highly promising anticancer targeting agents which exhibit additive effects of photodynamic therapy and hormone therapy.