Improving therapeutic potential of non-viral minimized DNA vectors

Non-Invasive Vaccines: Challenges in Formulation and Vaccine Adjuvants

Given the limitations of conventional invasive vaccines, such as the requirement for a cold chain system and trained personnel, needle-based injuries, and limited immunogenicity, non-invasive vaccines have gained significant attention. Although numerous approaches for formulating and administrating non-invasive vaccines have emerged, each of them faces its own challenges associated with vaccine bioavailability, toxicity, and other issues. To overcome such limitations, researchers have created novel supplementary materials and delivery systems. The goal of this review article is to provide vaccine formulation researchers with the most up-to-date information on vaccine formulation and the immunological mechanisms available, to identify the technical challenges associated with the commercialization of non-invasive vaccines, and to guide future research and development efforts.

Improving cell and gene therapy safety and performance using next-generation Nanoplasmid vectors

The cell and gene therapy industry has employed the same plasmid technology for decades in vaccination, cell and gene therapy, and as a raw material in viral vector and RNA production. While canonical plasmids contain antibiotic resistance markers in bacterial backbones greater than 2,000 base pairs, smaller backbones increase expression level and durability and reduce the cell-transfection-associated toxicity and transgene silencing that can occur with canonical plasmids. Therefore, the small backbone and antibiotic-free selection method of Nanoplasmid vectors have proven to be a transformative replacement in a wide variety of applications, offering a greater safety profile and efficiency than traditional plasmids. This review provides an overview of the Nanoplasmid technology and highlights its specific benefits for various applications with examples from recent publications.

Versatile seamless DNA vector production in E. coli using enhanced phage lambda integrase

Seamless DNA vectors derived from bacterial plasmids are devoid of bacterial genetic elements and represent attractive alternatives for biomedical applications including DNA vaccines. Larger scale production of seamless vectors employs engineered Escherichia coli strains in order to enable tightly regulated expression of site-specific DNA recombinases which precisely delete unwanted sequences from bacterial plasmids. As a novel component of a developing lambda integrase genome editing platform, we describe here strain MG1655-ISC as a means to easily produce different scales of seamless vectors, ranging in size from a few hundred base pairs to more than ten kilo base pairs. Since we employed an engineered lambda integrase that is able to efficiently recombine pairs of DNA crossover sites that differ in sequence, the resulting seamless vectors will be useful for subsequent genome editing in higher eukaryotes to accommodate variations in target site sequences. Future inclusion of single cognate sites for other genome targeting systems could enable modularity. These features, together with the demonstrated simplicity of in vivo seamless vector production, add to their utility in the biomedical space.

Immunotherapy and immunoengineering for breast cancer; a comprehensive insight into CAR-T cell therapy advancements, challenges and prospects

BACKGROUND

Breast cancer (BC) is a highly prevalent solid cancer with a high-rise infiltration of immune cells, turning it into a significant candidate for tumor-specific immunotherapies. Chimeric antigen receptor (CAR)-T cells are emerging as immunotherapeutic tools with genetically engineered receptors to efficiently recognize and attack tumor cells that express specific target antigens. Technological advancements in CAR design have provided five generations of CAR-T cells applicable to a wide range of cancer patients while boosting CAR-T cell therapy safety. However, CAR-T cell therapy is ineffective against breast cancer because of the loss of specified antigens, the immunosuppressive nature of the tumor and CAR-T cell-induced toxicities. Next-generation CAR-T cells actively pass through the tumor vascular barriers, persist for extended periods and disrupt the tumor microenvironment (TME) to block immune escape.

CONCLUSION

CAR-T cell therapy embodies advanced immunotherapy for BC, but further pre-clinical and clinical assessments are recommended to achieve maximized efficiency and safety.

Changing Fate: Reprogramming Cells via Engineered Nanoscale Delivery Materials

The incorporation of nanotechnology in regenerative medicine is at the nexus of fundamental innovations and early-stage breakthroughs, enabling exciting biomedical advances. One of the most exciting recent developments is the use of nanoscale constructs to influence the fate of cells, which are the basic building blocks of healthy function. Appropriate cell types can be effectively manipulated by direct cell reprogramming; a robust technique to manipulate cellular function and fate, underpinning burgeoning advances in drug delivery systems, regenerative medicine, and disease remodeling. Individual transcription factors, or combinations thereof, can be introduced into cells using both viral and nonviral delivery systems. Existing approaches have inherent limitations. Viral-based tools include issues of viral integration into the genome of the cells, the propensity for uncontrollable silencing, reduced copy potential and cell specificity, and neutralization via the immune response. Current nonviral cell reprogramming tools generally suffer from inferior expression efficiency. Nanomaterials are increasingly being explored to address these challenges and improve the efficacy of both viral and nonviral delivery because of their unique properties such as small size and high surface area. This review presents the state-of-the-art research in cell reprogramming, focused on recent breakthroughs in the deployment of nanomaterials as cell reprogramming delivery tools.

Therapeutic Effects and Repair Mechanism of HGF Gene-Transfected Mesenchymal Stem Cells on Injured Endometrium

There are many studies on the advantages of using mesenchymal stem cells (MSCs) that secrete various paracrine factors for repairing endometrial injury. However, the stability and effectiveness of MSCs require improvement to become a viable therapy. Hepatocyte growth factor (HGF), one of the cytokines secreted by MSCs, promotes vascular repair and mesenchymal to epithelial transformation (MET). Therefore, HGF likely promotes the repair process of the endometrium. We prepared MSCs transfected with the HGF gene to explore its repair effects and mechanism using a damaged endometrium mouse model. HGF gene-transfected MSCs were prepared by electroporation. The transfected MSCs retained their cellular characteristics and significantly increased the expression of HGF ( $P<0.01$ ). HGF gene-transfected MSCs helped damaged endometrium to recover its morphological characteristics, improved proliferation and decreased apoptosis of endometrial cells, increased the expression of endometrial vascular growth-related factors, and activated phosphorylated c-Met and AKT in the mouse endometrial damage model ( $P<0.05$ ). Compared with normal MSCs, HGF gene-transfected MSCs produced a more significant effect on damaged endometrial epithelium repair by activating the HGF/c-Met and downstream signaling pathways. Our results indicate that HGF gene-transfected MSCs provide an effective and promising tool for injured endometrium therapy.

Supercoiling and looping promote DNA base accessibility and coordination among distant sites

DNA in cells is supercoiled and constrained into loops and this supercoiling and looping influence every aspect of DNA activity. We show here that negative supercoiling transmits mechanical stress along the DNA backbone to disrupt base pairing at specific distant sites. Cooperativity among distant sites localizes certain sequences to superhelical apices. Base pair disruption allows sharp bending at superhelical apices, which facilitates DNA writhing to relieve torsional strain. The coupling of these processes may help prevent extensive denaturation associated with genomic instability. Our results provide a model for how DNA can form short loops, which are required for many essential processes, and how cells may use DNA loops to position nicks to facilitate repair. Furthermore, our results reveal a complex interplay between site-specific disruptions to base pairing and the 3-D conformation of DNA, which influences how genomes are stored, replicated, transcribed, repaired, and many other aspects of DNA activity.