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Preparation of Neutrally-charged, pH-responsive Polymeric Nanoparticles for Cytosolic siRNA Delivery
Published on: May 2, 2019
Co-delivery of siRNA and hypericin into cancer cells by hyaluronic acid modified PLGA-PEI nanoparticles
Yanan Li1, Junling Zhang2, Buhai Wang2
1a Department of Pharmaceutics , State Key Laboratory of Natural Medicines, School of Pharmacy, China Pharmaceutical University , Nanjing , China .
Context:
Malignant tumors cause more death because of the resistance of the hypoxic cancer cell toward radiotherapy. Targeting for hypoxic cancer area and gene silencing to overcome the hypoxia are two kinds of important therapeutic strategies for treating tumors.
Objective:
In order to explore the combined effects of gene therapy and hypericin (Hy) on tumor cells, hypoxia-inducible factor 1 alpha (HIF-1α) small interfering ribonucleic acid (siRNA) was transfected into the hypoxic human nasopharyngeal carcinoma (CNE2) cells using Hy-encapsulated nanocomplexes (Hy-HPP NPs) as a carrier which would achieve dual targeting to the tumor necrosis area.
Materials And Methods:
NPs were prepared by emulsion-diffusion-evaporation method. Formulations were evaluated by conducting in vitro physicochemical studies, electrophoresis, in vivo study, and biochemical studies.
Results And Discussions:
Hy-loaded nanoparticles with a mean size of around 160 nm was able to enhance the accumulation in the tumors by enhanced permeability and retention effect. The electrophoresis confirmed the good stability of siRNA/Hy-HPP NPs in the presence of phosphate-buffered saline (pH 7.4), competitive heparin, and RNase. The results of transfection showed that the uptake of siRNA was significantly increased up to 50% in CNE2 cells. The level of the HIF-1α with Hy-encapsulated nanocomplexes was significantly reduced to 30% in the transfected CNE2 cells. In vivo studies, the carrier exhibited higher intensity at the tumor tissue cells and higher affinity toward the necrotic tumor tissue.
Conclusion:
Results demonstrated that Hy-HPP NPs could significantly enhance the tranfection efficiency of siRNA, suggesting Hy-encapsulated nanoparticle as an efficient gene carrier. The co-delivery of HIF-1α siRNA (siHIF-1α) and Hy could efficiently decrease the level of HIF-1α and increase the affinity toward necrotic tissues. Hence, this is a promising strategy for further application in radiotherapy.
Insights
This study developed hypericin-encapsulated nanocomplexes (Hy-HPP NPs) to deliver hypoxia-inducible factor 1 alpha siRNA (siHIF-1α) into hypoxic tumor cells. The NPs effectively silenced HIF-1α, enhancing radiotherapy potential.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Cancer Therapy
Background:
- Hypoxic cancer cells exhibit radioresistance, posing a challenge for radiotherapy.
- Targeting hypoxic regions and gene silencing are key strategies to overcome tumor hypoxia.
Purpose of the Study:
- To investigate the combined effects of gene therapy and hypericin (Hy) on tumor cells.
- To utilize Hy-encapsulated nanocomplexes (Hy-HPP NPs) for dual targeting of hypoxic nasopharyngeal carcinoma (CNE2) cells and gene silencing of HIF-1α.
Main Methods:
- Nanoparticles (NPs) were synthesized using the emulsion-diffusion-evaporation method.
- Physicochemical, electrophoretic, in vitro, and in vivo studies were conducted to evaluate NP formulations.
- siRNA targeting HIF-1α (siHIF-1α) was encapsulated within Hy-HPP NPs for co-delivery.
Main Results:
- Hy-HPP NPs demonstrated enhanced tumor accumulation via the EPR effect, with a mean size of ~160 nm.
- Electrophoresis confirmed the stability of siRNA/Hy-HPP NPs under various conditions.
- siRNA uptake in CNE2 cells increased by 50%, and HIF-1α levels were reduced by 30% post-transfection.
- In vivo studies showed higher NP intensity and affinity for necrotic tumor tissues.
Conclusions:
- Hy-HPP NPs serve as efficient gene carriers, significantly enhancing siRNA transfection efficiency.
- Co-delivery of siHIF-1α and Hy effectively reduces HIF-1α levels and targets necrotic tumor tissues.
- This approach presents a promising strategy for enhancing radiotherapy efficacy.
