4 research outputs found
Tumor Acidity/NIR Controlled Interaction of Transformable Nanoparticle with Biological Systems for Cancer Therapy
Precisely controlling
the interaction of nanoparticles with biological systems (nanobio
interactions) from the injection site to biological targets shows
great potential for biomedical applications. Inspired by the ability
of nanoparticles to alter their physicochemical properties according
to different stimuli, we explored the tumor acidity and near-infrared
(NIR) light activated transformable nanoparticle <sup>DA</sup>TAT-NP<sub>IR&DOX</sub>. This nanoparticle consists of a tumor acidity-activated
TAT [the TAT lysine residues’ amines was modified with 2,3-dimethylmaleic
anhydride (DA)], a flexible chain polyphosphoester core coencapsulated
a NIR dye IR-780, and DOX (doxorubicin). The physicochemical properties
of the nanoparticle can be controlled in a stepwise fashion using
tumor acidity and NIR light, resulting in adjustable nanobio interactions.
The resulting transformable nanoparticle <sup>DA</sup>TAT-NP<sub>IR&DOX</sub> efficiently avoids the interaction with mononuclear phagocyte system
(MPS) (“stealth” state) due to the masking of the TAT
peptide during blood circulation. Once it has accumulated in the tumor
tissues, <sup>DA</sup>TAT-NP<sub>IR&DOX</sub> is reactivated by
tumor acidity and transformed into the “recognize” state
in order to promote interaction with tumor cells and enhance cellular
internalization. Then, this nanoparticle is transformed into “attack”
state under NIR irradiation, achieving the supersensitive DOX release
from the flexible chain polyphosphoester core in order to increase
the DOX–DNA interaction. This concept provides new avenues
for the creation of transformable drug delivery systems that have
the ability to control nanobio interactions
Acetal-Linked Hyperbranched Polyphosphoester Nanocarriers Loaded with Chlorin e6 for pH-Activatable Photodynamic Therapy
Nanocarrier-mediated
photodynamic therapy (PDT), which involves the systemic delivery of
photosensitizers (PSs) into tumor tissue and tumor cells, has emerged
as an attractive treatment for cancer. However, insufficient PS release
limits intracellular cytotoxic reactive oxygen species (ROS) generation,
which has become a major obstacle to improving the PDT therapeutic
efficacy. Herein, a novel hyperbranched polyphosphoester (hbPPE) containing
numerous acetal bonds (S-hbPPE/Ce6) was explored as a chlorin e6 (Ce6)
nanocarrier for PDT. S-hbPPE/Ce6 with a branched topological structure
efficiently encapsulated Ce6 and then significantly enhanced its internalization
by tumor cells. Subsequently, the endo-/lysosomal acid microenvironment
rapidly cleaved the acetal linkage of S-hbPPE and destroyed the nanostructure
of S-hbPPE/Ce6, resulting in increased Ce6 release and obviously elevated
the intracellular ROS generation under illumination. Therefore, treatment
with S-hbPPE/Ce6 noticeably enhanced the PDT therapeutic efficacy,
indicating that such a pH-sensitive hbPPE nanocarrier has great potential
to improve the PDT therapeutic efficacy for cancer therapy
Ultrathin Black Phosphorus Nanosheets for Efficient Singlet Oxygen Generation
Benefiting from its strong oxidizing
properties, the singlet oxygen
has garnered serious attentions in physical, chemical, as well as
biological studies. However, the photosensitizers for the generation
of singlet oxygen bear in low quantum yields, lack of long wavelength
absorption band, poor biocompatibility, undegradable in living tissues,
and so on. Here we first demonstrate the exfoliated black phosphorus
nanosheets to be effective photosensitizers for the generation of
singlet oxygen with a high quantum yield of about 0.91, rendering
their attractive applications in catalysis and photodynamic therapy.
Through in vitro and in vivo studies, the water dispersible black
phosphorus nanosheets show notable cancer therapy ability. In addition,
the photodegradable character of black phosphorus from element to
biocompatible phosphorus oxides further highlights its therapeutic
potential against cancer. This study will not only expand the breadth
of study in black phosphorus but also offer an efficient catalyst
and photodynamic therapy agent
ROS-Sensitive Polymeric Nanocarriers with Red Light-Activated Size Shrinkage for Remotely Controlled Drug Release
Drug
delivery systems with remotely controlled drug release capability
are rather attractive options for cancer therapy. Herein, a reactive
oxygen species (ROS)-sensitive polymeric nanocarrier TK-PPE@NP<sub>Ce6/DOX</sub> was explored to realize remotely controlled drug release
by light-activated size shrinkage. The TK-PPE@NP<sub>Ce6/DOX</sub> encapsulating chlorin e6 (Ce6) and doxorubicin (DOX) was self-assembled
from an innovative ROS-sensitive polymer TK-PPE with the assistance
of an amphiphilic copolymer polyÂ(ethylene glycol)-<i>b</i>-polyÂ(ε-caprolactone) (PEG-<i>b</i>-PCL). Under the
660 nm red light irradiation, ROS generated by the encapsulated Ce6
were capable of cleaving the TK linker <i>in situ</i>, which
resulted in the rapid degradation of the TK-PPE@NP<sub>Ce6/DOX</sub> core. Consequently, the size of TK-PPE@NP<sub>Ce6/DOX</sub> shrank
from 154 ± 4 nm to 72 ± 3 nm, and such size shrinkage affected
further triggered rapid DOX release. As evidenced by both <i>in vitro</i> and <i>in vivo</i> experiments, such
ROS-sensitive polymeric nanocarriers with light-induced size shrinkage
capability offer remarkable therapeutic effects in cancer treatment.
This concept provides new avenues for the development of light-activated
drug delivery systems for remotely controlled drug release <i>in vivo</i>