. Author manuscript; available in PMC: 2019 Jul 1.

Published in final edited form as: J Colloid Interface Sci. 2018 Feb 20;521:261–279. doi: 10.1016/j.jcis.2018.02.053

Table 3.

Functions of silica in integrated nanoparticles.

Formulations	Function
Silica core	High dielectric constant enhances light absorption¹⁶⁸, Therapeutic reservoir for drug delivery^158,169,170, Increase ultrasound contrast¹²⁹
Silica shell	Facilitates functionalization of NPs surface^168,171, Amplifies photoacoustic signal¹⁷², Therapeutic reservoir for drug delivery¹⁷³, Enhances colloidal and chemical stability of the core¹⁷⁴, Separates core from outside layer¹⁷⁵, Decreases cytotoxicity of core¹⁶⁰
Silica matrix	Prevents photobleaching of fluorophores¹⁴⁴, Decreases cytotoxicity^{113, 176, 177}