Executive Summary : | Breast cancer has the second-highest incidence rate compared to all the different types of cancer. Both detected and treatment of breast cancer is challenging. Presently utilized treatments like chemotherapy and radiation therapy come with a price of frequent side effects. Both photothermal therapy (PTT) and photodynamic therapy (PDT), which have great photothermal conversion efficiency in treating various diseases and tumors, are emerging as an effective alternative to conventional therapy. When exposed to NIR light, PTT primarily uses an optically-absorbing substance, followed by nonradiative energy loss, leading to thermal ablation of tumors. PDT involves the administration of a photosensitizer (PS) followed by local excitation of PS by a particular wavelength and resulting in the generation of cytotoxic reactive oxygen species, which can cause damage to tumor cells. Upconversion is a nonlinear anti-Stokes process in which low-energy NIR light is sequentially converted into high-energy light, like visible light. Due to characteristics like optical tunability, large light penetration depth, negligible autofluorescence, chemical stability, and long lifetime, lanthanide-based Upconversion nanoparticles UCNPs may be promising and effective imaging fluorophores in comparison to conventional fluorophores. These UCNPs can also be functionalized with active moieties that are cancer cell lines specific to target tumors. Additionally, these UCNPs may also be coupled with PS for possible therapeutic anticancer applications like PDT or PTT. Thulium (Tm3+), Erbium (Er3+), and Hafnium (Ho3+) are the emitters that can emit different colors, and Ytterbium (Yb3+) serves as the sensitizer in the majority of the UCNPs currently in use. An additional dopant like Nd3+ can be incorporated in UCNP which may cause it to be excited by triggers with two different wavelengths (980 nm and 808 nm). These UCNPs can transfer the upconverted NIR photons to PS via the LRET process. These UCNPs can transfer the upconverted NIR photons to PS via the LRET process, considering the absorbance PS overlaps with the emission of UCNP. Various PS materials like metal oxides (MO), including ZnO, TiO2, or ferrites, can be used by considering their match with the emission of UCNP (Nd →Yb→Tm/Er/Ho→MO). Thus, combining the imaging properties of tri-doped UCNP (NaYF4:Yb,Tm,Nd) and MO as the photosensitizer (PS), we present a hybrid multi-imaging model consisting of UCNP clubbed with PS. This system can be triggered by both 808nm and 980nm laser sources. Thus, being a multi-trigger imaging and a potential therapeutic agent for breast cancer. Further, this hybrid material can be further functionalized with agents like antibodies or drugs for targeting, making it breast cancer-specific. Thus, the system will selectively target, diagnose and image the breast cancer using multiwavelength handheld probe. |