High-Performance Multi-Dynamic Bond Cross-Linked Hydrogel with Spatiotemporal siRNA Delivery for Gene-Cell Combination Therapy of Intervertebral Disc Degeneration

Chronic inflammatory diseases, such as intervertebral disc degeneration (IVDD), which affect the lives of hundreds of millions of people, still lack effective and precise treatments. In this study, a novel hydrogel system with many extraordinary properties is developed for gene-cell combination therapy of IVDD. Phenylboronic acid-modified G5 PAMAM (G5-PBA) is first synthesized, and therapeutic siRNA silencing the expression of P65 mixed with G5-PBA (siRNA@G5-PBA) is then embedded into the hydrogel (siRNA@G5-PBA@Gel) based on multi-dynamic bonds including acyl hydrazone bonds, imine linkage, π-π stacking, and hydrogen bonding interactions. Local and acidic inflammatory microenvironment-responsive gene-drug release can achieve spatiotemporal regulation of gene expression. In addition, gene-drug release from the hydrogel can be sustained for more than 28 days in vitro and in vivo, greatly inhibiting the secretion of inflammatory factors and the subsequent degeneration of nucleus pulposus (NP) cells induced by lipopolysaccharide (LPS). Through prolonged inhibition of the P65/NLRP3 signaling pathway, the siRNA@G5-PBA@Gel is verified to relieve inflammatory storms, which can significantly enhance the regeneration of IVD when combined with cell therapy. Overall, this study proposes an innovative system for gene-cell combination therapy and a precise and minimally invasive treatment method for IVD regeneration.

Fluorinated polyamidoamine dendrimer-mediated miR-23b delivery for the treatment of experimental rheumatoid arthritis in rats

In rheumatoid arthritis (RA), insufficient apoptosis of macrophages and excessive generation of pro-inflammatory cytokines are intimately connected, accelerating the development of disease. Here, a fluorinated polyamidoamine dendrimer (FP) is used to deliver miR-23b to reduce inflammation by triggering the apoptosis of as well as inhibiting the inflammatory response in macrophages. Following the intravenous injection of FP/miR-23b nanoparticles in experimental RA models, the nanoparticles show therapeutic efficacy with inhibition of inflammatory response, reduced bone and cartilage erosion, suppression of synoviocyte infiltration and the recovery of mobility. Moreover, the nanoparticles accumulate in the inflamed joint and are non-specifically captured by synoviocytes, leading to the restoration of miR-23b expression in the synovium. The miR-23b nanoparticles target Tab2, Tab3 and Ikka to regulate the activation of NF-κB pathway in the hyperplastic synovium, thereby promoting anti-inflammatory and anti-proliferative responses. Additionally, the intravenous administration of FP/miR-23b nanoparticles do not induce obvious systemic toxicity. Overall, our work demonstrates that the combination of apoptosis induction and inflammatory inhibition could be a promising approach in the treatment of RA and possibly other autoimmune diseases.

Polymeric nanomedicines for the treatment of hepatic diseases

The liver is an important organ in the human body and performs many functions, such as digestion, detoxification, metabolism, immune responses, and vitamin and mineral storage. Therefore, disorders of liver functions triggered by various hepatic diseases, including hepatitis B virus infection, nonalcoholic steatohepatitis, hepatic fibrosis, hepatocellular carcinoma, and transplant rejection, significantly threaten human health worldwide. Polymer-based nanomedicines, which can be easily engineered with ideal physicochemical characteristics and functions, have considerable merits, including contributions to improved therapeutic outcomes and reduced adverse effects of drugs, in the treatment of hepatic diseases compared to traditional therapeutic agents. This review describes liver anatomy and function, and liver targeting strategies, hepatic disease treatment applications and intrahepatic fates of polymeric nanomedicines. The challenges and outlooks of hepatic disease treatment with polymeric nanomedicines are also discussed.

Phenylboronic-acid-based Functional Chemical Materials for Fluorescence Imaging and Tumor Therapy

Various functional chemical materials have been widely used in imaging and tumor therapy. Targeted ligands such as antibodies, peptides, and small molecules have been combined with functional materials to enhance cellular uptake and are used for active targeting of cancer cells and tumors. Among them, phenylboronic acid (PBA), as a small molecular ligand, has the characteristics of low cytotoxicity and easy modification. PBA improves the cancer cell imaging and tumor treatment effect by binding to glycans on the surface of cancer cells. In this Mini-Review, we introduced the modification strategy and targeting strategy of PBA. We focused on the applications of PBA-based functional materials in fluorescence imaging and tumor therapy. For fluorescence imaging, the potential of PBA-based functional chemical materials in cancer diagnosis and tumor targeting was proved by cell imaging and in vivo imaging. For tumor therapy, we mainly discussed the applications of PBA-based functional chemical materials in chemotherapy, gene therapy, phototherapy, and immunotherapy. PBA-based functional chemical materials provide a useful method for cancer diagnosis and treatment.

Genome editing of PD-L1 mediated by nucleobase-modified polyamidoamine for cancer immunotherapy

Immune checkpoint blockade therapy against programmed death protein-1 and its ligand (PD-1/PD-L1) has been accepted as a promising approach to activate the immune system's anti-tumor response. Although small interfering RNA...

Phenylboronic Acid-Modified Polyamidoamine Mediated the Transfection of Polo-Like Kinase-1 siRNA to Achieve an Anti-Tumor Efficacy

Background

The construction of tumor-targeting carriers with favorable transfection efficiency was of great significance to achieve the tumor gene therapy. The phenylboronic acid-modified polyamidoamine (namely PP) was employed as a carrier for the delivery of Polo-like kinase-1 siRNA (siPlk-1), inducing an obvious anti-tumor response.

Materials and Methods

The interaction between PP and siPlk-1 was evaluated by gel retardation assay. The transfection efficiency and tumor-targeting ability were analyzed by flow cytometry and confocal laser scanning microscopy, using hepatocarcinoma cell line HepG2 as a model. The anti-proliferation effect of PP/siPlk-1 and related mechanism were studied using the strategies of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell apoptosis and cell cycle arrest. The anti-migration effect induced by PP/siPlk-1 delivery was assayed by wound healing and Transwell migration techniques. Finally, quantitative real-time PCR and Western blotting were performed to measure the expression level of Plk-1 and other key targets.

Results

The derivative PP could achieve the condensation of siPlk-1 into stable nanoparticles at nitrogen/phosphate groups ratio (N/P ratio) of >3.0, and it could facilitate the transfection of siPk-1 in a phenylboronic acid-dependent manner. The PP/siPlk-1 nanoparticles exhibited obvious anti-proliferation effect owing to the gene silence of Plk-1, which was identified to be associated with the cell apoptosis and cell cycle arrest at G2 phase. Meanwhile, PP/siPlk-1 transfection could efficiently suppress the migration and invasion of tumor cells.

Conclusion

The derivative PP has been demonstrated to be an ideal tumor-targeting carrier for the delivery of Plk-1 siRNA, exhibiting great potential in the gene therapy of malignant tumors.

Dual ATP/reduction-responsive polyplex to achieve the co-delivery of doxorubicin and miR-23b for the cancer treatment

Combination therapy based on the co-delivery of therapeutic genes and anti-cancer drugs has emerged as a promising approach in the cancer treatment, and stimuli-responsive delivery systems could further improve the therapeutic efficacy. Herein, an ATP aptamer and its complementary DNA were used to form Duplex into which doxorubicin (DOX) was loaded to construct DOX-Duplex, and then the lipoic acid-modified oligoethyleneimine (LA-OEI) was employed as a carrier to realize the co-delivery of DOX-Duplex and miR-23b. The ternary nanocomplex LA-OEI/miR-23b/DOX-Duplex showed excellent anti-proliferative effect by inducing the cell apoptosis via mitochondrial signaling pathway and arresting the cell cycle at S phase. Meanwhile, the co-delivery of DOX-Duplex and miR-23b could efficiently inhibit the metastasis of cancer cells by reducing the expression level of MMP-9. The favorable anti-tumor efficacy of ternary nanocomplex was attributed to the rapid drug release in response to intracellular ATP concentration and reduction conditions and the synergistic effect between DOX-Duplex and miR-23b. Thus, ATP aptamer and reduction-responsive polymer provided a convenient platform to construct dual stimuli-responsive systems for the co-delivery of gene and drug in the cancer treatment.

Fluoropolymer-Mediated Intracellular Delivery of miR-23b for the Osteocyte Differentiation in Osteoblasts

Emerging evidence suggests that microRNAs (miRNAs) play key roles in the regulation of multiple biological processes, including the differentiation of osteoblasts. Although miRNA-based gene therapy holds immense potential in the treatment of a variety of diseases, the intracellular delivery of miRNA remains challenging owing to the lack of efficient and safe gene carriers. In this study, a fluoropolymer (FP) is constructed through the modification of polyamidoamine (PAMAM) using heptafluorobutyric anhydride and then is used as a carrier for miR-23b transfection to induce osteocyte differentiation of osteoblasts. The derivative FP is found to facilitate miR-23b transfection due to its favorable endosomal escape from the "proton sponge" effect. Compared to PAMAM/miR-23b, the FP/miR-23b nanocomplex efficiently promotes the differentiation of osteoblasts and formation of calcified nodules, attributable to enhanced expression of various osteogenesis genes (runt-related transfection factor 2 [RUNX2], alkaline phosphatase [ALP], osteopontin [OPN], and osteocalcin [OCN]). Thus, FP-mediated miR-23b transfection may be used as an effective strategy to facilitate osteogenic differentiation.

Nanoassemblies with Effective Serum Tolerance Capability Achieving Robust Gene Silencing Efficacy for Breast Cancer Gene Therapy

The transfection efficiency of siRNA mediated by cationic polymers is limited due to the instability of polymers/siRNA complexes in the presence of serum. Poly(ethylene glycol) (PEG) is usually applied to modify cationic polymers, so as to reduce protein and cell adsorption and then to improve siRNA transfection efficiency. However, the polymers' modification with PEG mostly consumes the free amino of the polymers, which can, in turn, reduce the charge density and limit their siRNA transfection efficacy. Here, a new PEG modification strategy that need not consume the surface aminos of polymers is proposed. Catechol-PEG polymers are coated on the surface of phenylboronic acid (PBA)-modified Generation 5 (G5) poly(amidoamine) dendrimers (G5PBA) via reversible boronate esters to establish PEG-modified dendrimer/siRNA nanoassemblies for efficient siRNA delivery. The PEG/G5PBA/siRNA nanoassemblies have positive charge and show excellent gene silencing efficacy in the absence of serum in vitro. More importantly, the PEG/G5PBA/siRNA nanoassemblies also exhibit excellent serum resistance and gene silencing efficacy in serum-containing medium. Furthermore, the effective antiserum and gene silencing efficacy elicited by these nanoassemblies lead to excellent antitumor effects in vivo. This proposed strategy constitutes an important approach to reach an excellent gene silencing efficacy in the presence of serum.

Application of new lysine-based peptide dendrimers D3K2 and D3G2 for gene delivery: Specific cytotoxicity to cancer cells and transfection in vitro

In order to enhance intracellular uptake and accumulation of therapeutic nucleic acids for improved gene therapy methods, numerous delivery vectors have been elaborated. Based on their origin, gene carriers are generally classified as viral or non-viral vectors. Due to their significantly reduced immunogenicity and highly optimized methods of synthesis, nanoparticles (especially those imitating natural biomolecules) constitute a promising alternative for virus-based delivery devices. Thus, we set out to develop innovative peptide dendrimers for clinical application as transfection agents and gene carriers. In the present work we describe the synthesis of two novel lysine-based dendritic macromolecules (D3K2 and D3G2) and their initial characterization for cytotoxicity/genotoxicity and transfection potential in two human cell line models: cervix adenocarcinoma (HeLa) and microvascular endothelial (HMEC-1). This approach allowed us to identify more cationic D3K2 as potent delivery agent, being able to increase intracellular accumulation of large nucleic acid molecules such as plasmids. Moreover, the dendrimers exhibited specific cytotoxicity towards cancer cell line without showing significant toxic effects on normal cells. These observations are promising prognosis for future clinical application of this type of nanoparticles.