Research Progress on Responsive Formulations for Cancer Prevention and Early Diagnosis

Malignant tumors have become an urgent public health challenge worldwide. A wealth of clinical evidence indicates that intervening during the precancerous stage is the most cost-effective means of reducing the risk of cancer and improving patients’ long-term survival rates. Conventional cancer prevention formulations generally suffer from shortcomings such as insufficient targeting capability, short retention time at the lesion site, and low bioavailability in vivo. Furthermore, pharmacological prevention and lesion diagnosis are not integrated, making it difficult to meet the practical clinical needs for targeted intervention in precancerous lesions [6]. Stimulus-responsive (smart) formulations can recognize characteristic signals in the microenvironment of precancerous lesions and early-stage tumors, including pH changes, elevated levels of reactive oxygen species, elevated glutathione levels, high expression of specific proteases at the lesion site, and specific enzymes produced by gut microbiota. By responding to microenvironmental triggers to achieve localized, targeted drug release at the lesion site while simultaneously activating imaging signals, these formulations have opened up new avenues for early cancer prevention and early screening [16]. This article reviews the recent advances in stimulus-responsive formulations for cancer prevention and early diagnosis. It discusses targeted delivery systems for small-molecule chemopreventive agents, oral formulations responsive to the intestinal microenvironment, and mucosal delivery systems for the prevention and control of epithelial cancers. It also summarizes microenvironment-responsive imaging probes, biomarker-activated theranostic prodrugs, and nanosensor-based diagnostic technologies for body fluid samples, and introduces multifunctional nanoplatforms that combine preventive and diagnostic functions. Finally, it analyzes the practical challenges associated with biosafety, large-scale production, and clinical translation [4], and discusses future directions for the development of next-generation smart responsive formulations, with the aim of informing the development of novel formulations for cancer prevention and early diagnosis.