Near-Infrared Fluorescent Hydroxyapatite Nanoparticles for Targeted Photothermal Cancer Therapy

Abstract

Near-infrared (NIR) fluorophores have attracted great attention due to their excellent optical and photothermal properties. Among them, a bone-targeted NIR fluorophore (named P800SO3) contains two phosphonate groups, which play important roles in binding with hydroxyapatite (HAP) as the main mineral component of bones. In this study, biocompatible and NIR fluorescent HAP nanoparticles functionalized with P800SO3 and polyethylene glycol (PEG) were readily prepared for tumor-targeted imaging and photothermal therapy (PTT). The PEGylated HAP nanoparticle (HAP800-PEG) demonstrated improved tumor targetability with high tumor-to-background ratios (TBR). Moreover, the HAP800-PEG also showed excellent photothermal properties, and the temperature of tumor tissue reached 52.3 °C under NIR laser irradiation, which could completely ablate the tumor tissue without recurrence. Therefore, this new type of HAP nanoparticle has great potential as a biocompatible and effective phototheranostic material, which enables the use of P800SO3 for targeted photothermal cancer treatment.

Polyethyleneimine incorporated hydroxyapatite for improved colloidal stability

“…It is a major component of the bones and teeth in vertebrates 1,2 . HAP has the advantages of high biocompatibility, biostability, bioactivity, and stability, making it widely applied in the field of bioceramics 3–6 . Furthermore, HAP has been utilized in various applications, including bone grafting, drug/gene delivery, protein adsorption, hydroxyapatite coatings, and catalytic supports 7–12 .…”

An Insight to the Various Applications of Hydroxyapatite

“…HAp theranostic agents can be applied to the oncology field. HAp nanoparticles can be engineered to deliver chemotherapy drugs or gene therapies to tumour cells while being visualised using imaging modalities for accurate tumour targeting and therapy monitoring [50] . HAp theranostics can also be used in tissue engineering and regenerative medicine applications [51] .…”

High-Performance Hybrid Phototheranostics for NIR-IIb Fluorescence Imaging and NIR-II-Excitable Photothermal Therapy

“…Among all the phototherapy methodologies, photothermal therapy (PTT), which adopts photothermal agents (PTAs) to convert absorbed photons into hyperthermia, is an attractive tumor treatment modality [ 12 , 13 , 14 , 15 , 16 ]. Numerous studies have demonstrated that photothermal therapy exhibits remarkable efficacy in cancer treatment [ 17 , 18 , 19 ].…”