RESUMO
The in vivo fate is a crucial factor that governs the successful translation of nanoformulations. However, one of the current biggest challenges is with the real-time monitoring of the body of the nanoparticles themselves. Conventional radioactive or fluorescent probes give signals even after they are disassociated from the particle matrix, generating interference to bioimaging and leading to misjudgment of results. Environment-responsive fluorescent dyes are regarded as promising tools due to signal switching in response to the changes in the environment. Currently, there are three categories of dyes in bioimaging of nanoparticles based on Förster resonance energy transfer (FRET), aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ). They have similar characteristics that strong fluorescence is emitted when they are embedded in the matrix of nanocarriers, whereas the fluorescence quenches upon release from the matrix due to dissociation of nanocarriers. The fluorescence switching reflects the existing status of the nanocarriers and therefore helps to interpret the in vivo behaviors. FRET and AIE probes have been widely used in elucidating the interactions between nanoparticles and cell models. However, they show intrinsic defects in studying in vivo fate of nanoparticles. ACQ-based dyes are sensitive to water, a universal factor in the biological environment. Therefore, with the help of bioimaging equipment, the in vivo trafficking process of nanoparticles can be unraveled. This review article tends to provide an overview on the rationale, pros and cons and applications of the three categories of environment-responsive fluorescent dyes in the investigation of the in vivo fate of nanocarriers.
RESUMO
With the development of medical nanotechnology, scientists have found that nanoparticle drug delivery system can improve the accumulation of anti-tumor drugs inside the tumor and reduce the damage to normal tissues, so as to increase the treatment effect while decrease its side effect. In recent years, the nanoparticle drug delivery system has been gradually developing towards intellectualization, and various smart probes which are stimuli-responsive and sensitive to microenvironment of tumor have been designed. Those probes can be divided into two categories: internal (including pH, enzyme, and redox) and external (including light, temperature, ultrasound, and magnetic field) environment-responsive probes. In this paper, the latest research progress in the two kinds of environment-responsive smart probes in the field of tumor therapy is reviewed, and the further research direction is also prospected.
RESUMO
With the development of polymeric materials and nanotechnology, the potential application of nanoscaled drug delivery system (NDDS) is gradually manifested in the field of pharmaceutics. Especially, NDDS has the obvious advantages in the delivery of gene or drug. Comparing to the delivery system of single-drug, co-delivery system of gene and drug can significantly improve the therapeutic effects by enhancing transfection efficiency of gene and reversing multidrug resistance, etc. The co-delivery systems of gene and drug, which had the triggered release characteristics in the inner and outer of tumor, could be constructed by introducing the environment-responsive (pH-responsive, redox-responsive and light-responsive, etc) groups into the co-delivery system. The antitumor activity was further improved. In the present paper, the environment- responsive delivery systems in the application of co-delivery gene and drug in recent years were reviewed, and their remarkable properties in the antitumor activity were analyzed and summarized.