Designing idiosyncratic hmPCL -siRNA nanoformulated capsules for silencing and cancer therapy

Cas13b-mediated RNA targeted therapy alleviates genetic dilated cardiomyopathy in mice

BACKGROUND

Recent advances in gene editing technology have opened up new avenues for in vivo gene therapy, which holds great promise as a potential treatment method for dilated cardiomyopathy (DCM). The CRISPR-Cas13 system has been shown to be an effective tool for knocking down RNA expression in mammalian cells. PspCas13b, a type VI-B effector that can be packed into adeno-associated viruses and improve RNA knockdown efficiency, is a potential treatment for diseases characterized by abnormal gene expression.

RESULTS

Using PspCas13b, we were able to efficiently and specifically knockdown the mutant transcripts in the AC16 cell line carrying the heterozygous human TNNT2R141W (hTNNT2R141W) mutation. We used adeno-associated virus vector serotype 9 to deliver PspCas13b with specific single guide RNA into the hTNNT2R141W transgenic DCM mouse model, effectively knocking down hTNNT2R141W transcript expression. PspCas13b-mediated knockdown significantly increased myofilament sensitivity to Ca2+, improved cardiac function, and reduced myocardial fibrosis in hTNNT2R141W DCM mice.

CONCLUSIONS

These findings suggest that targeting genes through Cas13b is a promising approach for in vivo gene therapy for genetic diseases caused by aberrant gene expression. Our study provides further evidence of Cas13b's application in genetic disease therapy and paves the way for future applicability of genetic therapies for cardiomyopathy.

Novel imidazolium-thiohydantoin hybrids and their Mn(iii) complexes for antimicrobial and anti-liver cancer applications

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study. The findings of elemental analyses, spectral analyses and magnetic measurements will be used to infer the stoichiometry, coordination styles, and geometrical aspects of Mn(iii)IMTHs. The new compounds were evaluated for their chemotherapeutic potential against ESKAPE pathogens and liver cancer (HepG2). According to the MIC and MBC values, the bactericidal and bacteriostatic activities of IMTHs have been significantly improved following coordination with the Mn(iii) ion. The MTT assay results showed that all Mn(iii)IMTHs had the potential to reduce the viability of liver carcinoma (HepG2) cells in a dose-dependent manner, with the BF₄-supported complex (6b) outperforming its counterparts (6a and 6c) as well as a clinical anticancer drug (VBL). Additionally, Mn-IMTH₂ (6b) showed the highest level of selectivity (SI = 32.05) for targeting malignant cells (HepG2) over healthy cells (HL7702).

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study.

Dynamic covalent hydrogel of natural product baicalin with antibacterial activities

Baicalin has been demonstrated to have multiple pharmacological activities but low solubility. Various baicalin hydrogels have been used to improve its solubility and break its limitation in clinical applications. However, traditional baicalin hydrogels contain numerous ingredients and usually show low baicalin loading capacity. Herein, we discovered a dynamic covalent hydrogel only consisting of baicalin and inorganic borate, in which baicalin is considered as the carrier and drug without other ingredients. The dynamic boronate bonds endow the hydrogel with excellent degradability and multi-stimuli-responsiveness. Moreover, the hydrogel displayed remarkable thixotropy, moldability, and self-healing properties. And the biocompatible baicalin hydrogel exhibited significant antibacterial activities, and can be considered as a potential drug delivery system for biomedical applications.

Organic/Inorganic Self-Assembled Hybrid Nano-Architectures for Cancer Therapy Applications

Since the conceptualization of nanomedicine, numerous nanostructure-mediated drug formulations have progressed into clinical trials for treating cancer. However, recent clinical trial results indicate such kind of drug formulations has a limited improvement on the antitumor efficacy. This is due to the biological barriers associated with those formulations, for example, circulation stability, extravasation efficiency in tumor, tumor penetration ability, and developed multi-drug resistance. When employing for nanomedicine formulations, pristine organic-based and inorganic-based nanostructures have their own limitations. Accordingly, organic/inorganic (O/I) hybrids have been developed to integrate the merits of both, and to minimize their intrinsic drawbacks. In this context, the recent development in O/I hybrids resulting from a self-assembly strategy will be introduced. Through such a strategy, organic and inorganic building blocks can be self-assembled via either chemical covalent bonds or physical interactions. Based on the self-assemble procedure, the hybridization of four organic building blocks including liposomes, micelles, dendrimers, and polymeric nanocapsules with five functional inorganic nanoparticles comprising gold nanostructures, magnetic nanoparticles, carbon-based materials, quantum dots, and silica nanoparticles will be highlighted. The recent progress of these O/I hybrids in advanced modalities for combating cancer, such as, therapeutic agent delivery, photothermal therapy, photodynamic therapy, and immunotherapy will be systematically reviewed.

5-Fluorouracil enhances the chemosensitivity of gastric cancer to TRAIL via inhibition of the MAPK pathway

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has the ability to selectively trigger cancer cell apoptosis and can be used as a target for tumor therapy. However, gastric cancer cells are usually insensitive to TRAIL so reducing this drug resistance may improve the treatment of gastric cancer. In this study, we used Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) experiments to determine the effects of 5-fluorouracil (5-FU) and TRAIL on the proliferation of gastric cancer cells. An Annexin V/propidium iodide (PI) staining experiment was used to detect apoptosis, and Western blotting was used to analyze the expression levels of apoptosis-related proteins and mitogen-activated protein kinase (MAPK) pathway proteins. The antitumor effects of 5-FU and TRAIL were verified in vivo using a nude mouse tumorigenesis experiment, and a TUNEL assay was performed to evaluate apoptosis in tumor tissue from the nude mice. We found the combination of 5-FU and TRAIL had a greater inhibitory effect on the proliferation of gastric cancer cells than 5-FU or TRAIL alone both in vivo and in vitro. 5-FU enhanced TRAIL-induced gastric cancer cell apoptosis by inactivating the MAPK pathway. Overall, our analysis firstly provided new insights into the role of 5-FU in increasing sensitivity to TRAIL. 5-FU can be used as a sensitizer for TRAIL, and its administration is a potential strategy for the treatment of gastric cancer.

Biomimicked and CPMV-Imprinted Hollow Porous Zinc Phosphate Nanocapsules and Their Therapeutic Efficiency

Hollow zinc phosphate nanocapsules (hZPNCs) are an alloplastic biomaterial that has been synthesized to deliver chemotherapeutic drugs in a sustained manner. A very simple one-pot synthesis approach has been employed to synthesize hZPNCs by using cowpea mosaic virus (CPMV) in the presence of phosphate buffer (PBS) (0.01 M PBS, pH ∼7.2) with zinc acetate precursor. The synthesis mechanism of hZPNCs relies on the basis of biomineralization, where the precursor molecules initiate mineralization with the help of amino acid residues present on the CPMV capsid. The synthesized hollow nanocapsules were of diameter ∼50-60 nm and porous shell with thickness of ∼4 nm. The cavity performed as a reservoir for the anticancer drugs (DOX and IM). The release kinetic studies show the positive aspect of hZPNCs to be labeled as drug delivery cargo for sustained delivery. In vitro cytotoxic studies of hZPNCs and hZPNCs-chemo drugs on HEK293, HEPG2, and K562 cells were performed. The cytotoxic studies show that hZPNCs-DOX and hZPNCs-IM arrest the cell cycle of carcinoma cells (HEPG2 and K562 cells) at relatively low IC₅₀ and that the inhibition efficiency is dosage dependent. Furthermore, through HRTEM, in vitro cellular interactions of carcinoma cells with hZPNCs and chemo drug-loaded hZPNCs were confirmed by the cryo-sectioning of cells before and after the incubation. These studies revealed the likely endocytic pathway for the nanocapsules entering the cell and executing the specific action of delivering the anticancer drugs. Together, these results reveal the hZPNCs as potential sustained drug delivery agents.

Effective in vitro delivery of paclitaxel by nanocargo of mesoporous polycaprolactone against triple negative breast cancer cells by minimalizing drug dose

Among the breast cancers, triple negative breast cancer (TNBC) has relatively poor outcomes with a lower survival rate and personalised chemotherapy is the only option available for treatment. Currently in the biomedical domain, nanomaterials with porous morphology have revealed their tremendous possibilities to be used as a nanocarrier in treating cancer by offering void space to encapsulate/entrap biological agents. However, the development of nanocarrier-based targeted therapy with high therapeutic efficacy and fewer side effects to normal cells is always a challenge. Here, we have developed nanocargos based on biodegradable mesoporous PCL (polycaprolactone) of approx. diameter of 75 nm by template removal synthesis techniques. Succeeding the comparative analysis of the nanocarriers, the efficiencies of core shell PCL-mZnO (PZ) and mesoporous PCL (HPZ) to deliver paclitaxel (Taxol/T) into breast cancer cells, is investigated. We found that HPZ nanocapsules have less cytotoxicity and drug loading efficiency of about 600 μg mg-1. The Taxol-loaded nanoparticles (T-HPZ) have exhibited more cytotoxicity than Taxol alone treated cancer cells. Furthermore, T-HPZ treated MDA-MB231 cells are accumulated at G2/M phase of the cell cycle and eventually undergo apoptosis. In support of this, anchorage independent growth of MDA-MB231 cells are significantly inhibited by T-HPZ treatment. Together, our findings suggest that T-HPZ-based paclitaxel (Taxol/T) loaded nanoparticles provide a novel therapeutic option in the treatment of TNBC.

Targeted delivery of HES5-siRNA with novel polypeptide-modified nanoparticles for hepatocellular carcinoma therapy

For actively targeted delivery of small interfering RNA (siRNA) to solid tumors, we fabricated functionalized selenium nanoparticles (SeNPs) decorated with the polypeptide RGDfC. Herein, RGDfC was used as tumor-targeted moiety and installed onto the surface of SeNPs to enhance the cellular uptake. RGDfC-SeNPs@siRNA were internalized into the HepG2 cell mainly through clathrin-mediated endocytosis. The active efficacy of the RGDfC-SeNPs@siRNA was confirmed via gene silencing assay, MTT assay and flow cytometry analysis. Owing to the tumor-targeting effect of RGDfC, RGDfC-SeNPs@siRNA achieved an obvious improvement in gene silencing ability, which led to significant growth inhibition of HepG2 cells. Furthermore, treatment with RGDfC-SeNPs@siRNA resulted in greater antitumor efficacy than lipofectamine 2000@siRNA in vitro and in vivo. In addition, the RGDfC-SeNPs@siRNA was almost non-toxic to the key organs of mice. In sum, these findings provide an alternative therapeutic route for targeted cancer treatments.

A novel polypeptide RGDfC-modified selenium nanoparticle was fabricated to selectively deliver HES5-siRNA to tumors for hepatocellular carcinoma therapy.

Hollow polymer nanocapsules: synthesis, properties, and applications

Hollow polymer nanocapsules (HPNs) have gained tremendous interest in recent years due to their numerous desirable properties compared to their solid counterparts.

Bio-inspired synthesis of a hierarchical self-assembled zinc phosphate nanostructure in the presence of cowpea mosaic virus: in vitro cell cycle, proliferation and prospects for tissue regeneration

Self-assembly is an important auto-organization process used in designing structural biomaterials which have the potential capability to heal tissues after traumatic injury. Although various materials having the ability to heal after injury are available, there is still a substantial need to develop new improved materials. To address this issue, we have developed hierarchical three-dimensional (3D) self-assembled zinc phosphate (Zn₃(PO₄)₂) in the presence of cowpea mosaic virus (CPMV). Zn₃(PO₄)₂ nanoparticles are self-assembled into nanosheets with a high degree of isotropy and then self-organized into a 3D structure that can enhance surface interactions with biological entities. The self-assembled structure is formed through the auto-organization of nanoparticles of size ∼50 nm under the influence of CPMV. The cellular response of self-assembled Zn₃(PO₄)₂ and cell-particle adhesion behavior have been investigated through in vitro studies using modeled osteoblast-like MG63 cells. Self-assembled Zn₃(PO₄)₂ resulted in proliferation of MG63 cells of up to 310% within 7 days of incubation. A 15% higher proliferation was obtained than with commercially available hydroxyapatite (HAp). Immunofluorescent analysis of MG63 cells after co-culturing with self-assembled Zn₃(PO₄)₂ confirmed the healthy cytoskeletal organization and dense proliferation of MG63 cells. Further, Zn₃(PO₄)₂ exhibited ∼28% cell-cycle progression in S phase, which is higher than obtained with commercially available HAp. Overall, these results demonstrate the multiple functions of hierarchical self-assembled Zn₃(PO₄)₂ in the regeneration of bone tissue without defects and increasing the formation of cellular networks, and suggest its use in bone tissue engineering.

Poly-N-acryloyl-(l-phenylalanine methyl ester) hollow core nanocapsules facilitate sustained delivery of immunomodulatory drugs and exhibit adjuvant properties

Polymeric hollow nanocapsules have attracted significant research attention as novel drug carriers and their preparation is of particular concern owing to the feasibility to encapsulate a broad range of drug molecules. This work presents for the first time the synthesis and development of novel poly-N-acryloyl l-phenylalanine methyl ester hollow core nanocapsules (NAPA-HPNs) of avg. size ca. 100-150 nm by the mini-emulsion technique. NAPA-HPNs are biocompatible and capable of encapsulating sodium nitroprusside (SNP) at a rate of ∼1.3 μM per mg of capsules. These NAPA-HPNs + SNP nano-formulations maintained homeostasis of macrophages which carry and facilitate the action of various drug molecules used against various diseases. These NAPA-HPNs also facilitate the prolonged release of a low level of nitric oxide (NO) and enhance the metabolic activities of pro-inflammatory macrophages, which are important for the action of various drugs in body fluids. NAPA-HPN mediated skewing of naïve macrophages toward the M1 phenotype potentially demonstrates its adjuvant action on the innate immune system. These results potentially suggested that NAPA-HPNs can serve both as a carrier of drugs as well as an adjuvant for the immune system. Thus, these nanocapsules could be used for the effective management of various infectious or tumor diseases where immune-stimulation is paramount for treatment.

Targeted delivery of siRNA using RGDfC-conjugated functionalized selenium nanoparticles for anticancer therapy

Lack of biocompatible and effective delivery carriers is a significant shortcoming for siRNA-mediated cancer therapy. To overcome these limitations, selenium nanoparticles (SeNPs) have been proposed for siRNA transfection vehicles. In this study, we synthesized novel RGDfC peptide modified selenium nanoparticles (RGDfC-SeNPs) as a gene vehicle, which was expected to improve the tumor-targeted delivery activity. RGDfC-SeNPs were compacted with siRNAs (anti-Oct4) by electrostatic interaction, which was capable of protecting siRNA from degradation. RGDfC-SeNPs exhibited excellent ability to deliver siRNA into HepG2 cells. siRNA transfection assay showed that RGDfC-SeNPs presented a higher gene silencing efficacy than conventional lipofectamine 2000. The cytotoxicity of RGDfC-SeNPs/siRNA on normal cells was lower than that on tumor cells, indicating that RGDfC-SeNPs/siRNA exhibited selectivity between normal and cancer cells. Additionally, Oct4 knockdown mediated by the selenium nanoparticle transfection arrested HepG2 cells mainly at the G2/M phase and significantly induced HepG2 cell apoptosis. Western blotting results showed that RGDfC-SeNPs/siRNA might trigger Wnt/β-catenin signaling, and further activate a BCL-2 apoptosis-related signaling pathway to advance HepG2 cell apoptosis. In vivo biodistribution experiments indicated that RGDfC-SeNPs/siRNA nanoparticles were specifically targeted to the HepG2 tumors. Most importantly, RGDfC-SeNPs/siRNA inhibited tumor growth significantly and induced HepG2 cell apoptosis via silencing the Oct4 gene. In addition, the results of H&E staining demonstrated that RGDfC-SeNPs/siRNA had negligible toxicity on the major organs of mice. In a word, this study provides a novel strategy for the design of biocompatible and effective siRNA delivery vehicles in cancer therapy.