Tetrahedral DNA nanostructures functionalized by multivalent microRNA132 antisense oligonucleotides promote the differentiation of mouse embryonic stem cells into dopaminergic neurons

The effect of nanomaterials on embryonic stem cell neural differentiation: a systematic review

BACKGROUND

Humans' nervous system has a limited ability to repair nerve cells, which poses substantial challenges in treating injuries and diseases. Stem cells are identified by the potential to renew their selves and develop into several cell types, making them ideal candidates for cell replacement in injured neurons. Neuronal differentiation of embryonic stem cells in modern medicine is significant. Nanomaterials have distinct advantages in directing stem cell function and tissue regeneration in this field. We attempted in this systematic review to collect data, analyze them, and report results on the effect of nanomaterials on neuronal differentiation of embryonic stem cells.

METHODS

International databases such as PubMed, Scopus, ISI Web of Science, and EMBASE were searched for available articles on the effect of nanomaterials on neuronal differentiation of embryonic stem cells (up to OCTOBER 2023). After that, screening (by title, abstract, and full text), selection, and data extraction were performed. Also, quality assessment was conducted based on the STROBE checklist.

RESULTS

In total, 1507 articles were identified and assessed, and then only 29 articles were found eligible to be included. Nine studies used 0D nanomaterials, ten used 1D nanomaterials, two reported 2D nanomaterials, and eight demonstrated the application of 3D nanomaterials. The main biomaterial in studies was polymer-based composites. Three studies reported the negative effect of nanomaterials on neural differentiation.

CONCLUSION

Neural differentiation is crucial in neurological regenerative medicine. Nanomaterials with different characteristics, particularly those cellular regulating activities and stem cell fate, have much potential in neural tissue engineering. These findings indicate a new understanding of potential applications of physicochemical cues in nerve tissue engineering.

Cell-therapy for Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Cell-based strategies focusing on replacement or protection of dopaminergic neurons have been considered as a potential approach to treat Parkinson's disease (PD) for decades. However, despite promising preclinical results, clinical trials on cell-therapy for PD reported mixed outcomes and a thorough synthesis of these findings is lacking. We performed a systematic review and meta-analysis to evaluate cell-therapy for PD patients.

METHODS

We systematically identified all clinical trials investigating cell- or tissue-based therapies for PD published before July 2023. Out of those, studies reporting transplantation of homogenous cells (containing one cell type) were included in meta-analysis. The mean difference or standardized mean difference in quantitative neurological scale scores before and after cell-therapy was analyzed to evaluate treatment effects.

RESULTS

The systematic literature search revealed 106 articles. Eleven studies reporting data from 11 independent trials (210 patients) were eligible for meta-analysis. Disease severity and motor function evaluation indicated beneficial effects of homogenous cell-therapy in the 'off' state at 3-, 6-, 12-, or 24-month follow-ups, and for motor function even after 36 months. Most of the patients were levodopa responders (61.6-100% in different follow-ups). Cell-therapy was also effective in improving the daily living activities in the 'off' state of PD patients. Cells from diverse sources were used and multiple transplantation modes were applied. Autografts did not improve functional outcomes, while allografts exhibited beneficial effects. Encouragingly, both transplantation into basal ganglia and to areas outside the basal ganglia were effective to reduce disease severity. Some trials reported adverse events potentially related to the surgical procedure. One confirmed and four possible cases of graft-induced dyskinesia were reported in two trials included in this meta-analysis.

CONCLUSIONS

This meta-analysis provides preliminary evidence for the beneficial effects of homogenous cell-therapy for PD, potentially to the levodopa responders. Allogeneic cells were superior to autologous cells, and the effective transplantation sites are not limited to the basal ganglia. PROSPERO registration number: CRD42022369760.

The Current Progress of Tetrahedral DNA Nanostructure for Antibacterial Application and Bone Tissue Regeneration

Recently, programmable assembly technologies have enabled the application of DNA in the creation of new nanomaterials with unprecedented functionality. One of the most common DNA nanostructures is the tetrahedral DNA nanostructure (TDN), which has attracted great interest worldwide due to its high stability, simple assembly procedure, high predictability, perfect programmability, and excellent biocompatibility. The unique spatial structure of TDN allows it to penetrate cell membranes in abundance and regulate cellular biological properties as a natural genetic material. Previous studies have demonstrated that TDNs can regulate various cellular biological properties, including promoting cells proliferation, migration and differentiation, inhibiting cells apoptosis, as well as possessing anti-inflammation and immunomodulatory capabilities. Furthermore, functional molecules can be easily modified at the vertices of DNA tetrahedron, DNA double helix structure, DNA tetrahedral arms or DNA tetrahedral cage structure, enabling TDN to be used as a nanocarrier for a variety of biological applications, including targeted therapies, molecular diagnosis, biosensing, antibacterial treatment, antitumor strategies, and tissue regeneration. In this review, we mainly focus on the current progress of TDN-based nanomaterials for antimicrobial applications, bone and cartilage tissue repair and regeneration. The synthesis and characterization of TDN, as well as the biological merits are introduced. In addition, the challenges and prospects of TDN-based nanomaterials are also discussed.

Nanotherapeutic and Stem Cell Therapeutic Strategies in Neurodegenerative Diseases: A Promising Therapeutic Approach

Neurodegeneration is characterized by progressive, disabling, and incurable neurological disorders with the massive loss of specific neurons. As one of the most promising potential therapeutic strategies for neurodegenerative diseases, stem cell therapy exerts beneficial effects through different mechanisms, such as direct replacement of damaged or lost cells, secretion of neurotrophic and growth factors, decreased neuroinflammation, and activation of endogenous stem cells. However, poor survival and differentiation rates of transplanted stem cells, insufficient homing ability, and difficulty tracking after transplantation limit their further clinical use. The rapid development of nanotechnology provides many promising nanomaterials for biomedical applications, which already have many applications in neurodegenerative disease treatment and seem to be able to compensate for some of the deficiencies in stem cell therapy, such as transport of stem cells/genes/drugs, regulating stem cell differentiation, and real-time tracking in stem cell therapy. Therefore, nanotherapeutic strategies combined with stem cell therapy is a promising therapeutic approach to treating neurodegenerative diseases. The present review systematically summarizes recent advances in stem cell therapeutics and nanotherapeutic strategies and highlights how they can be combined to improve therapeutic efficacy for the treatment of neurodegenerative diseases.

Advances in regenerative medicine applications of tetrahedral framework nucleic acid-based nanomaterials: an expert consensus recommendation

With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids (tFNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, tFNAs have been widely applied in the biomedical field as three-dimensional DNA nanomaterials. Surprisingly, tFNAs exhibit positive effects on cellular biological behaviors and tissue regeneration, which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity, tFNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization, intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic tFNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic tFNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone, cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.

Functionalizing Framework Nucleic-Acid-Based Nanostructures for Biomedical Application

Strategies for functionalizing diverse tetrahedral framework nucleic acids (tFNAs) have been extensively explored since the first successful fabrication of tFNA by Turberfield. One-pot annealing of at least four DNA single strands is the most common method to prepare tFNA, as it optimizes the cost, yield, and speed of assembly. Herein, the focus is on four key merits of tFNAs and their potential for biomedical applications. The natural ability of tFNA to scavenge reactive oxygen species, along with remarkable enhancement in cellular endocytosis and tissue permeability based on its appropriate size and geometry, promotes cell-material interactions to direct or probe cell behavior, especially to treat inflammatory and degenerative diseases. Moreover, the structural programmability of tFNA enables the development of static tFNA-based nanomaterials via engineering of functional oligonucleotides or therapeutic molecules, and dynamic tFNAs via attachment of stimuli-responsive DNA apparatuses, leading to potential applications in targeted therapies, tissue regeneration, antitumor strategies, and antibacterial treatment. Although there are impressive performance and significant progress, the challenges and prospects of functionalizing tFNA-based nanostructures are still indicated in this review.