An effective vaginal gel to deliver CRISPR/Cas9 system encapsulated in poly (β-amino ester) nanoparticles for vaginal gene therapy

Delivering CRISPR to the HIV-1 reservoirs

Human immunodeficiency virus type 1 (HIV-1) infection is well known as one of the most complex and difficult viral infections to cure. The difficulty in developing curative strategies arises in large part from the development of latent viral reservoirs (LVRs) within anatomical and cellular compartments of a host. The clustered regularly interspaced short palindromic repeats/ CRISPR-associated protein 9 (CRISPR/Cas9) system shows remarkable potential for the inactivation and/or elimination of integrated proviral DNA within host cells, however, delivery of the CRISPR/Cas9 system to infected cells is still a challenge. In this review, the main factors impacting delivery, the challenges for delivery to each of the LVRs, and the current successes for delivery to each reservoir will be discussed.

Post cross-linked ROS-responsive poly(β-amino ester)-plasmid polyplex NPs for gene therapy of EBV-associated nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most common tumors in South China and Southeast Asia and is thought to be associated with Epstein-Barr virus (EBV) infection. Downregulation of latent membrane protein 1 (LMP1) encoded by EBV can reduce the expression of NF-κB and PI3K, induce apoptosis, and inhibit the growth of EBV-related NPC. For targeted cleavage of the Lmp1 oncogene via the CRISPR/Cas9 gene editing system, a post cross-linked ROS-responsive poly(β-amino ester) (PBAE) polymeric vector was developed for the delivery of CRISPR/Cas9 plasmids both in vitro and in vivo. After composition optimization, the resultant polymer-plasmid polyplex nanoparticles (NPs) showed a diameter of ∼230 nm and a zeta potential of 22.3 mV with good stability. Compared with the non-cross-linked system, the cross-linked NPs exhibited efficient and quick cell uptake, higher transfection efficiency in EBV-positive C666-1 cells (53.5% vs. 40.6%), more efficient gene editing ability against the Mucin2 model gene (Muc2) (17.9% vs. 15.4%) and Lmp1 (8.5% vs. 5.6%), and lower intracellular reactive oxygen species (ROS) levels. The NPs achieved good tumor penetration and tumor growth inhibition in the C666-1 xenograft tumor model via Lmp1 cleavage, indicating their potential for gene therapy of EBV-related NPC.

Massively parallel CRISPR off-target detection enables rapid off-target prediction model building

BACKGROUND

CRISPR (clustered regularly interspaced short palindromic repeats) genome editing holds tremendous potential in clinical translation. However, the off-target effect has always been a major concern.

METHODS

Here, we have developed a novel sensitive and specific off-target detection method, AID-seq (adaptor-mediated off-target identification by sequencing), that can comprehensively and faithfully detect the low-frequency off targets generated by different CRISPR nucleases (including Cas9 and Cas12a).

FINDINGS

Based on AID-seq, we developed a pooled strategy to simultaneously identify the on/off targets of multiple gRNAs, as well as using mixed human and human papillomavirus (HPV) genomes to screen the most efficient and safe targets from 416 HPV gRNA candidates for antiviral therapy. Moreover, we used the pooled strategy with 2,069 single-guide RNAs (sgRNAs) at a pool size of about 500 to profile the properties of our newly discovered CRISPR, FrCas9. Importantly, we successfully built an off-target detection model using these off-target data via the CRISPR-Net deep learning method (area under the receiver operating characteristic curve [AUROC] = 0.97, area under the precision recall curve [AUPRC] = 0.29).

CONCLUSIONS

To our knowledge, AID-seq is the most sensitive and specific in vitro off-target detection method to date. And the pooled AID-seq strategy can be used as a rapid and high-throughput platform to select the best sgRNAs and characterize the properties of new CRISPRs.

FUNDING

This work was supported by The National Natural Science Foundation of China (grant nos. 32171465 and 82102392), the General Program of Natural Science Foundation of Guangdong Province of China (grant no. 2021A1515012438), Guangdong Basic and Applied Basic Research Foundation (grant no. 2020A1515110170), and the National Ten Thousand Plan-Young Top Talents of China (grant no. 80000-41180002).

Biomedical applications of nanomaterials in the advancement of nucleic acid therapy: Mechanistic challenges, delivery strategies, and therapeutic applications

In the past few decades, substantial advancement has been made in nucleic acid (NA)-based therapies. Promising treatments include mRNA, siRNA, miRNA, and anti-sense DNA for treating various clinical disorders by modifying the expression of DNA or RNA. However, their effectiveness is limited due to their concentrated negative charge, instability, large size, and host barriers, which make widespread application difficult. The effective delivery of these medicines requires safe vectors that are efficient & selective while having non-pathogenic qualities; thus, nanomaterials have become an attractive option with promising possibilities despite some potential setbacks. Nanomaterials possess ideal characteristics, allowing them to be tuned into functional bio-entity capable of targeted delivery. In this review, current breakthroughs in the non-viral strategy of delivering NAs are discussed with the goal of overcoming challenges that would otherwise be experienced by therapeutics. It offers insight into a wide variety of existing NA-based therapeutic modalities and techniques. In addition to this, it provides a rationale for the use of non-viral vectors and a variety of nanomaterials to accomplish efficient gene therapy. Further, it discusses the potential for biomedical application of nanomaterials-based gene therapy in various conditions, such as cancer therapy, tissue engineering, neurological disorders, and infections.

Poly(β-amino ester)s-based nanovehicles: Structural regulation and gene delivery

The first poly(β-amino) esters (PβAEs) were synthesized more than 40 years ago. Since 2000, PβAEs have been found to have excellent biocompatibility and the capability of ferrying gene molecules. Moreover, the synthesis process of PβAEs is simple, the monomers are readily available, and the polymer structure can be tailored to meet different gene delivery needs by adjusting the monomer type, monomer ratio, reaction time, etc. Therefore, PβAEs are a promising class of non-viral gene vector materials. This review paper presents a comprehensive overview of the synthesis and correlated properties of PβAEs and summarizes the progress of each type of PβAE for gene delivery. The review focuses in particular on the rational design of PβAE structures, thoroughly discusses the correlations between intrinsic structure and effect, and then finishes with the applications and perspectives of PβAEs.

Miniaturized Polymeric Systems for the Intravaginal Gene Therapies: Recent Update on Unconventional Delivery

The prevalence of vaginal infection is increasing among women, especially at reproductive age. For proper eradication of infection, the effective concentration of a drug is required at the infection site. Therefore, local delivery is recommended to exert a direct therapeutic effect at the site action that causes a reduction in dose and side effects. The main focus of vaginal drug delivery is to enhance retention time and patient compliance. The high recurrence rate of vaginal infection due to the lack of effective treatment strategies opens the door for new therapeutic approaches. To combat these setbacks, intravaginal gene therapies have been investigated. High attention has been gained by vaginal gene therapy, especially for sexually transmitted infection treatment. Despite much research, no product is available in the market, although in vitro and preclinical data support the vaginal route as an effective route for gene administration. The main focus of this review is to discuss the recent advancement in miniaturized polymeric systems for intravaginal gene therapies to treat local infections. An overview of different barriers to vaginal delivery and challenges of vaginal infection treatment are also summarised.

Emerging Bioactive Agent Delivery-Based Regenerative Therapies for Lower Genitourinary Tissues

Injury to lower genitourinary (GU) tissues, which may result in either infertility and/or organ dysfunctions, threatens the overall health of humans. Bioactive agent-based regenerative therapy is a promising therapeutic method. However, strategies for spatiotemporal delivery of bioactive agents with optimal stability, activity, and tunable delivery for effective sustained disease management are still in need and present challenges. In this review, we present the advancements of the pivotal components in delivery systems, including biomedical innovations, system fabrication methods, and loading strategies, which may improve the performance of delivery systems for better regenerative effects. We also review the most recent developments in the application of these technologies, and the potential for delivery-based regenerative therapies to treat lower GU injuries. Recent progress suggests that the use of advanced strategies have not only made it possible to develop better and more diverse functionalities, but also more precise, and smarter bioactive agent delivery systems for regenerative therapy. Their application in lower GU injury treatment has achieved certain effects in both patients with lower genitourinary injuries and/or in model animals. The continuous evolution of biomaterials and therapeutic agents, advances in three-dimensional printing, as well as emerging techniques all show a promising future for the treatment of lower GU-related disorders and dysfunctions.

Design and development of Branched Poly(ß-aminoester) nanoparticles for Interleukin-10 gene delivery in a mouse model of atherosclerosis

Atherosclerosis progression is a result of chronic and non-resolving inflammation, effective treatments for which still remain to be developed. We designed and developed branched poly(ß-amino ester) nanoparticles (NPs) containing plasmid DNA encoding IL-10, a potent anti-inflammatory cytokine to atherosclerosis. The NPs (NP-VHPK) are functionalized with a targeting peptide (VHPK) specific for VCAM-1, which is overexpressed by endothelial cells at sites of atherosclerotic plaque. The anionic coating affords NP-VHPK with significantly lower toxicity than uncoated NPs in both endothelial cells and red blood cells (RBCs). Following injection of NP-VHPK in ApoE^-/- mice, Cy5-labelled IL-10 significantly accumulates in both whole aortas and aortic sinus sections containing plaque compared to injection with a non-targeted control. Furthermore, IL-10 gene delivery results in an attenuation of inflammation locally at the plaque site. NP-VHPK may thus have the potential to reduce the inflammatory component of atherosclerosis in a safe and effective manner. STATEMENT OF SIGNIFICANCE: Atherosclerosis is a chronic inflammatory disease that results in the formation of lipid-laden plaques within vascular walls. Although treatments using drugs and antibodies are now beginning to address the inflammation in atherosclerosis, neither is sufficient for long-term therapy. In this paper, we introduce a strategy to deliver genes encoding the anti-inflammatory protein interleukin-10 (IL-10) in vivo. We showed that Branched Poly(ß-aminoester) carrying the IL-10 gene are able to localize specifically at the plaque via surface-functionalized targeting moieties against inflamed VCAM-1 and/or ICAM-1 and to facilitate gene transcription by ECs to increase the local concentration of the IL-10 within the plaque. To date, there is no report involving non-viral nanotechnology to provide gene-based therapies for atherosclerosis.

FrCas9 is a CRISPR/Cas9 system with high editing efficiency and fidelity

Genome editing technologies hold tremendous potential in biomedical research and drug development. Therefore, it is imperative to discover gene editing tools with superior cutting efficiency, good fidelity, and fewer genomic restrictions. Here, we report a CRISPR/Cas9 from Faecalibaculum rodentium, which is characterized by a simple PAM (5'-NNTA-3') and a guide RNA length of 21-22 bp. We find that FrCas9 could achieve comparable efficiency and specificity to SpCas9. Interestingly, the PAM of FrCas9 presents a palindromic sequence, which greatly expands its targeting scope. Due to the PAM sequence, FrCas9 possesses double editing-windows for base editor and could directly target the TATA-box in eukaryotic promoters for TATA-box related diseases. Together, our results broaden the understanding of CRISPR/Cas-mediated genome engineering and establish FrCas9 as a safe and efficient platform for wide applications in research, biotechnology and therapeutics.

Co-Delivery of p53 Restored and E7 Targeted Nucleic Acids by Poly (Beta-Amino Ester) Complex Nanoparticles for the Treatment of HPV Related Cervical Lesions

The p53 gene has the highest mutation frequency in tumors, and its inactivation can lead to malignant transformation, such as cell cycle arrest and apoptotic inhibition. Persistent high-risk human papillomavirus (HR-HPV) infection is the leading cause of cervical cancer. P53 was inactivated by HPV oncoprotein E6, promoting abnormal cell proliferation and carcinogenesis. To study the treatment of cervical intraepithelial neoplasia (CIN) and cervical cancer by restoring p53 expression and inactivating HPV oncoprotein, and to verify the effectiveness of nano drugs based on nucleic acid delivery in cancer treatment, we developed poly (beta-amino ester)537, to form biocompatible and degradable nanoparticles with plasmids (expressing p53 and targeting E7). In vitro and in vivo experiments show that nanoparticles have low toxicity and high transfection efficiency. Nanoparticles inhibited the growth of xenograft tumors and successfully reversed HPV transgenic mice’s cervical intraepithelial neoplasia. Our work suggests that the restoration of p53 expression and the inactivation of HPV16 E7 are essential for blocking the development of cervical cancer. This study provides new insights into the precise treatment of HPV-related cervical lesions.

The comparison of ZFNs, TALENs, and SpCas9 by GUIDE-seq in HPV-targeted gene therapy

Zinc-finger nucleases (ZFNs), transcription activator-like endonucleases (TALENs), and CRISPR-associated Cas9 endonucleases are three major generations of genome editing tools. However, no parallel comparison about the efficiencies and off-target activity of the three nucleases has been reported, which is critical for the final clinical decision. We for the first time developed the genome-wide unbiased identification of double-stranded breaks enabled by sequencing (GUIDE-seq) method in ZFNs and TALENs with novel bioinformatics algorithms to evaluate the off-targets. By targeting human papillomavirus 16 (HPV16), we compared the performance of ZFNs, TALENs, and SpCas9 in vivo. Our data showed that ZFNs with similar targets could generate distinct massive off-targets (287–1,856), and the specificity could be reversely correlated with the counts of middle “G” in zinc finger proteins (ZFPs). We also compared the TALENs with different N-terminal domains (wild-type [WT]/αN/βN) and G recognition modules (NN/NH) and found the design (αN or NN) to improve the efficiency of TALEN inevitably increased off-targets. Finally, our results showed that SpCas9 was more efficient and specific than ZFNs and TALENs. Specifically, SpCas9 had fewer off-target counts in URR (SpCas9, n = 0; TALEN, n = 1; ZFN, n = 287), E6 (SpCas9, n = 0; TALEN, n = 7), and E7 (SpCas9, n = 4; TALEN, n = 36). Taken together, we suggest that for HPV gene therapies, SpCas9 is a more efficient and safer genome editing tool. Our off-target data could be used to improve the design of ZFNs and TALENs, and the universal in vivo off-target detection pipeline for three generations of artificial nucleases provided useful tools for genome engineering-based gene therapy.

Women-specific routes of administration for drugs: A critical overview

The woman's body presents a number of unique anatomical features that can constitute valuable routes for the administration of drugs, either for local or systemic action. These are associated with genitalia (vaginal, endocervical, intrauterine, intrafallopian and intraovarian routes), changes occurring during pregnancy (extra-amniotic, intra-amniotic and intraplacental routes) and the female breast (breast intraductal route). While the vaginal administration of drug products is common, other routes have limited clinical application and are fairly unknown even for scientists involved in drug delivery science. Understanding the possibilities and limitations of women-specific routes is of key importance for the development of new preventative, diagnostic and therapeutic strategies that will ultimately contribute to the advancement of women's health. This article provides an overview on women-specific routes for the administration of drugs, focusing on aspects such as biological features pertaining to drug delivery, relevance in current clinical practice, available drug dosage forms/delivery systems and administration techniques, as well as recent trends in the field.