One-pot construction of a twice-condensed pDNA polyplex system for peripheral nerve crush injury therapy

The Biocomplex Assembled from Antigen Peptide and Toll-like Receptor Agonist Improved the Immunity against Pancreatic Adenocarcinoma In Vivo

Purpose

One of the biggest challenges in cancer immunotherapy is generating robust cancer-specific immunity. This work describes using a biocomplex assembled from a toll-like receptor agonist CpG oligodeoxynucleotide 1826 (CpG) and a pancreatic cancer antigen peptide mesothelin for tuning pancreatic tumor immunity.

Methods

This biocomplex was assembled via electrostatic interactions and characterized in size, morphology, zeta potential, and cargo loading. The effect of biocomplex on cell viability and activation of DCs and macrophages were measured by flow cytometry. The production of cytokines (GM-CSF, TNF, and IL-6) was evaluated by using ELISA kits. The effect of biocomplex on tumor cell proliferation was also evaluated by in vivo tumor model.

Result

We can modulate the surface charge of the biocomplex by simply varying the ratios of the two components. In cell models, this biocomplex did not impact cell viability in the antigen-presenting cell (i.e., dendritic cell and macrophage)-directed immunity. Moreover, this biocomplex regulated the secretion of tumor-related cytokines (i.e., GM-CSF, TNF, and IL-6) and promoted the activation of immune cell surface markers (i.e., CD80+, CD86+, and CD40+). In the mouse model, the biocomplex inhibited the tumor burden effectively and promoted the production of effector cytokines.

Conclusion

The present studies showed that the biocomplex with antigen peptide and toll-like receptor agonist was able to potentiate the antitumor immunity in vivo. This study will help understanding of immunity in pancreatic cancer and developing new immune therapeutic strategies for pancreatic adenocarcinoma.

Multifunctional biomimetic hydrogel based on graphene nanoparticles and sodium alginate for peripheral nerve injury therapy

Peripheral nerve injury (PNI) caused by injury may influence the patients' lifelong mobility unless there is an appropriate treatment. Tissue engineering has become a hot field to replace traditional autologous nerve transplantation due to its low surgical damage and easy-to-industrial advantages. Graphene (GR) is a kind of carbon nanomaterial with good electrical and mechanical properties that satisfy the demand for a good tissue scaffold for nerve regeneration. Herein, a novel and biosafe hydrogel is fabricated by using graphene and sodium alginate (GR-SA) together. This hydrogel not only can mimic the nerve growth microenvironment but also can promote the expression of neurotrophic substances and growth factors. Additionally, GR-SA hydrogel can significantly reduce inflammatory factors. Moreover, the results of both in vitro and in vivo tests demonstrate that GR-SA hydrogel has a promising prospect in PNI regeneration.

Two-Dimensional Nanomaterials for Peripheral Nerve Engineering: Recent Advances and Potential Mechanisms

Peripheral nerve tissues possess the ability to regenerate within artificial nerve scaffolds, however, despite the advance of biomaterials that support nerve regeneration, the functional nerve recovery remains unsatisfactory. Importantly, the incorporation of two-dimensional nanomaterials has shown to significantly improve the therapeutic effect of conventional nerve scaffolds. In this review, we examine whether two-dimensional nanomaterials facilitate angiogenesis and thereby promote peripheral nerve regeneration. First, we summarize the major events occurring after peripheral nerve injury. Second, we discuss that the application of two-dimensional nanomaterials for peripheral nerve regeneration strategies by facilitating the formation of new vessels. Then, we analyze the mechanism that the newly-formed capillaries directionally and metabolically support neuronal regeneration. Finally, we prospect that the two-dimensional nanomaterials should be a potential solution to long range peripheral nerve defect. To further enhance the therapeutic effects of two-dimensional nanomaterial, strategies which help remedy the energy deficiency after peripheral nerve injury could be a viable solution.

A Low-Molecular-Weight Polyethylenimine/pDNA-VEGF Polyplex System Constructed in a One-Pot Manner for Hindlimb Ischemia Therapy

Peripheral arterial disease (PAD) is often characterized by continued reduction in blood flow supply to limbs. Advanced therapeutic strategies like gene therapy could potentially be applied to limb ischemia therapy. However, developing a gene delivery system with low toxicity and high efficiency remains a great challenge. In this study, a one-pot construction was used to integrate vector synthesis and polyplex fabrication simultaneously in a simple and robust manner. We fabricated an interpenetrating gene delivery network through the physical interaction between low-molecular-weight polyethylenimine (PEI 1.8 kDa) and plasmid DNA (pDNA) and the chemical bonding between PEI and glutaraldehyde (GA), which was named the glutaraldehydelinked-branched PEI (GPEI) polyplex. The final GPEI polyplex system was pH-responsive and biodegradable due to the imine linkage and it could successfully deliver desired vascular endothelial growth factor (VEGF) pDNA. Compared with PEI (25 kDa)/pDNA polyplexes, GPEI polyplexes showed lower cytotoxicity and higher transfection efficiency both in vitro and in vivo. In addition, we demonstrated that GPEI polyplexes could efficiently promote the formation of new capillaries in vivo, which may provide a practicable strategy for clinical hindlimb ischemia therapy in the future.