Multifunctional integrated fiber-optic probe for in vivo tumor identification, therapy, and efficacy assessment

The limited light penetration depth and the systemic toxicity of nanomaterials hinder the clinical translation of phototheranostics. Against these backgrounds, the combination of optical fiber and photo-theranostics agents has attracted widespread attention as a viable solution. However, the multiplexing potential of fiber-optic theranostics probe has not been fully exploited. In this work, a multifunctional integrated fiber-optic probe was developed by co-modifying pH indicator, temperature indicator, and photothermal agent on the surface of one single tapered optical fiber. The excitation bands of these agents do not overlap with each other. Thus, the fiber-optic probe exhibited different functionals under different excitation wavelengths without crosstalk. Before therapy, the probe can reveal the tumor acidification gradient to realize tumor edge identification. During therapy, the photothermal agent can convert light energy to heat and thus realize photothermal therapy (PTT). At the same time, through temperature monitoring, precise control of therapeutic dose can be achieved. After therapy, through the dynamic monitoring of pH, rapid efficacy assessment can be realized. This study provides a paradigm for the multifunctional integration of fiber-optic theranostics probes, which is expected to play an important role in oncology clinical medicine and tumor mechanism research.