Co-delivery of photosensitizer and diclofenac through sequentially responsive bilirubin nanocarriers for combating hypoxic tumors

Considering that photodynamic therapy (PDT)-induced oxygen consumption and microvascular damage could exacerbate hypoxia to drive more glycolysis and angiogenesis, a novel approach to potentiate PDT and overcome the resistances of hypoxia is avidly needed. Herein, morpholine-modified PEGylated bilirubin was proposed to co-deliver chlorin e6, a photosensitizer, and diclofenac (Dc). In acidic milieu, the presence of morpholine could enable the nanocarriers to selectively accumulate in tumor cells, while PDT-generated reactive oxidative species (ROS) resulted in the collapse of bilirubin nanoparticles and rapid release of Dc. Combining with Dc showed a higher rate of apoptosis over PDT alone and simultaneously triggered a domino effect, including blocking the activity and expression of lactate dehydrogenase A (LDHA), interfering with lactate secretion, suppressing the activation of various angiogenic factors and thus obviating hypoxia-induced resistance-glycolysis and angiogenesis. In addition, inhibition of hypoxia-inducible factor-1α (HIF-1α) by Dc alleviated hypoxia-induced resistance. This study offered a sequentially responsive platform to achieve sufficient tumor enrichment, on-demand drug release and superior anti-tumor outcomes in vitro and in vivo.

Light-controllable charge-reversal nanoparticles with polyinosinic-polycytidylic acid for enhancing immunotherapy of triple negative breast cancer

Nucleic acid drugs are highly applicable for cancer immunotherapy with promising therapeutic effects, while targeting delivery of these drugs to disease lesions remains challenging. Cationic polymeric nanoparticles have paved the way for efficient delivery of nucleic acid drugs, and achieved stimuli-responsive disassembly in tumor microenvironment (TME). However, TME is highly heterogeneous between individuals, and most nanocarriers lack active-control over the release of loaded nucleic acid drugs, which will definitely reduce the therapeutic efficacy. Herein, we have developed a light-controllable charge-reversal nanoparticle (LCCN) with controlled release of polyinosinic-polycytidylic acid [Poly(I:C)] to treat triple negative breast cancer (TNBC) by enhanced photodynamic immunotherapy. The nanoparticles keep suitably positive charge for stable loading of Poly(I:C), while rapidly reverse to negative charge after near-infrared light irradiation to release Poly(I:C). LCCN-Poly(I:C) nanoparticles trigger effective phototoxicity and immunogenic cell death on 4T1 tumor cells, elevate antitumor immune responses and inhibit the growth of primary and abscopal 4T1 tumors in mice. The approach provides a promising strategy for controlled release of various nucleic acid-based immune modulators, which may enhance the efficacy of photodynamic immunotherapy against TNBC.

A nanocleaner specifically penetrates the blood‒brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer's disease

Insurmountable blood‒brain barrier (BBB) and complex pathological features are the key factors affecting the treatment of Alzheimer's disease (AD). Poor accumulation of drugs in lesion sites and undesired effectiveness of simply reducing A

Preparation of ROS responsive nano prodrug and its anti-tumor activity in vitro / 天津医药

Objective To design and synthesize a novel paclitaxel loaded nanoparticle with reactive oxygen species (ROS) response, and characterize its structure, and investigate its stability, in vitro drug responsive release, cellular uptake and in vitro antitumor activity. Methods The PEG-2S-PTX monomer was synthesized by coupling the hydrophilic polyethylene glycol (PEG) with hydrophobic paclitaxel (PTX) via a thioether chain (2S), and the prodrug nanoparticles (PEG-2S-PTX NPs) were prepared by self-assembly. Meanwhile, using succinic anhydride (SA) as the linking group to synthesize the PEG-SA-PTX monomer and prepare the other prodrug nanoparticles (PEG-SA-PTX NPs) as control. The structures of PEG-2S-PTX and PEG-SA-PTX monomer were confirmed by 1H-NMR. The diameter and stability of the nanoparticles were detected by dynamic light scattering (DLS). The PTX release kinetics under oxidizing condition was detected by high performance liquid chromatography (HPLC) method. And the cellular uptake efficiency of nanoparticles by MCF-7 cells was observed by fluorescence microscope. The in vitro antitumor effects of nanoparticles were compared by MTT assay. Results PEG-2S-PTX and PEG-SA-PTX could both be self-assemble into nanoparticles with the diameter of (92.15±12.42) nm and (113.20±12.16) nm. PEG-2S-PTX NPs could rapidly release PTX under oxidative condition while PEG-SA-PTX NPs only showed weak responsiveness. PEG-2S-PTX NPs could be more rapidly taken up by MCF-7 cells compared with PEG-SA-PTX NPs. They both showed concentration dependent anti-tumor effects, but the cytotoxicity of PEG-2S-PTX NPs was stronger than that of PEG-SA-PTX NPs in the concentrations of 0.05, 0.1, 5, 10, 50 and 100 mg/L (P<0.05). Conclusion As paclitaxel prodrug nanoparticles with ROS responsive ability, PEG-2S-PTX NPs can rapidly release PTX in response to ROS in tumor cells, and exhibit great anti-tumor activity in vitro.