Over the past decades, non-viral DNA and RNA delivery systems have been intensively studied as an alternative to viral vectors. Despite the most significant advantage over viruses, such as the lack of immunogenicity and cytotoxicity, the widespread use of non-viral carriers in clinical practice is still limited due to the insufficient efficacy associated with the difficulties of overcoming extracellular and intracellular barriers. Overcoming barriers by non-viral carriers is facilitated by their chemical structure, surface charge, as well as developed modifications. Currently, there are many different forms of non-viral carriers for various applications. This review aimed to summarize recent developments based on the essential requirements for non-viral carriers for gene therapy.

Spinal muscular atrophy 5q (SMA) is one of the most common neuromuscular inherited diseases and is the most common genetic cause of infant mortality. SMA is associated with homozygous deletion of exon 7 in the SMN1 gene. Recently developed drugs can improve the motor functions of infants with SMA when they are treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using a real-time PCR assay with dried blood spots (DBS) was performed from January 2022 through November 2022 in Saint Petersburg, which is a representative Russian megapolis. Here, 36,140 newborns were screened by the GenomeX real-time PCR-based screening test, and three genotypes were identified: homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns), and wild-type individuals (35,364 newborns). The disease status of all four newborns that screened positive for the homozygous SMN1 deletion was confirmed by alternate methods. Two of the newborns had two copies of SMN2, and two of the newborns had three copies. We determined the incidence of spinal muscular atrophy in Saint Petersburg to be 1 in 9035 and the SMA carrier frequency to be 1 in 47. In conclusion, providing timely information regarding SMN1, confirmation of disease status, and SMN2 copy number as part of the SMA newborn-screening algorithm can significantly improve clinical follow-up, testing of family members, and treatment of patients with SMA.

Uterine leiomyoma (UL) is a prevalent benign tumor in women that frequently gives rise to a multitude of reproductive complications. The use of suicide gene therapy has been proposed as a highly promising method for treating UL. To achieve successful gene therapy, it is essential to develop carriers that can efficiently transport nucleic acids into targeted cells and tissues. The instability of polyplexes in blood and other biological fluids is a crucial factor to consider when using non-viral carriers. In this study, we present serum-resistant and cRGD-modified DNA complexes for targeted delivery genes to UL cells. Ternary polyplexes were formed by incorporating cystine-cross-linked polyglutamic acid modified with histidine residues. We employed two techniques in the production of cross-linked polyanionic coating: matrix polymerization and oxidative polycondensation. In this study, we investigated the physicochemical properties of ternary DNA complexes, including the size and zeta-potential of the nanoparticles. Additionally, we evaluated cellular uptake, toxicity levels, transfection efficiency and specificity in vitro. The study involved introducing the HSV-TK gene into primary UL cells as a form of suicide gene therapy modeling. We have effectively employed ternary peptide-based complexes for gene delivery into the UL organtypic model. By implementing in situ suicide gene therapy, the increase in apoptosis genes expression was detected, providing conclusive evidence of apoptosis occurring in the transfected UL tissues. The results of the study strongly suggest that the developed ternary polyplexes show potential as a valuable tool in the implementation of suicide gene therapy for UL.

Endometriosis is a common gynecological condition that affects fertility in many women of reproductive age worldwide. This multifaceted disease exhibits a pathogenesis characterized by hormonal and immune system dysregulations, alongside increased angiogenic activity within the peritoneum. The aberrant proliferation of endometrial tissue outside the uterus is associated with vascularization in ectopic endometriotic lesions. Consequently, RNA interference (RNAi)-based angiogenic therapies targeting the VEGFA gene present a promising strategy for the treatment of endometriosis. To ensure the efficacy of RNAi-based therapy, it is critical to develop carriers capable of precisely delivering small interfering RNA (siRNA) to target cells. Additionally, the instability of polyplexes in vivo must be regarded as a pivotal aspect influencing the success of non-viral delivery. In this study, we introduce ternary polyplexes comprising siRNA and a carrier derived from an arginine–histidine-rich peptide, which is further coated with a glutamate–histidine-rich polymer modified using an SDF-1 chemokine-derived ligand for targeting CXCR4-expressing cells. The physicochemical characteristics of the siRNA-polyplexes, along with cellular toxicity and GFP gene silencing efficacy, were assessed in vitro. The anti-angiogenic potential of anti-VEGFA siRNA-polyplexes was evaluated by measuring the size of endometrial lesions, conducting immunohistochemical staining, and analyzing VEGFA gene expression. For in vivo experiment, a rat model of endometriosis induced by subcutaneous auto-transplantation of uterine tissue was utilized. A significant reduction in the growth of endometriotic implants and silencing of VEGFA gene expression was observed when compared to the saline-treated control group. The results of this study strongly suggest that the developed ternary polyplexes have significant potential as an efficient tool for the development of anti-angiogenic RNAi-based therapies for endometriosis.

Background: Endometriosis (EM) is a benign gynecological disorder characterized by the hyperproliferation of endometrial cells outside the uterus. This abnormal proliferation followed by neoangiogenesis leads to the formation of EM lesions, which often require surgical removal. Contemporary pharmacological treatment of EM involves hormonal therapies, which are frequently accompanied by adverse effects and a high rate of symptom recurrence following cessation of treatment. Consequently, the development of innovative pharmaceuticals is crucial for the effective management of EM. Small interfering RNA (siRNA) therapeutics are evolving from a niche modality into a major pharmaceutical platform applicable for the therapy of inherited and multifactorial diseases. However, a major obstacle hindering broader clinical use is the challenge of delivering siRNA to tissues beyond the liver. Peptide-based nanoparticles mediating siRNA delivery hold potential to overcome this limitation through receptor targeting and by shielding excessive positive charges. Methods: In the current study, we developed ternary polyplexes composed of anti-VEGFA siRNA, a cationic arginine-rich polymer, and an anionic glutamate-rich polymer modified with a cyclic RGD (cRGD) moiety for αVβ3-integrin binding. The polyplexes were characterized physicochemically, and their toxicity and GFP marker gene silencing properties were studied in vitro. Anti-angiogenic effects were evaluated in vivo using a surgically induced EM model in female Wistar rats. Results: A significant reduction in the volume of modeled EM lesions, along with decreased VEGFA gene expression and apparent reduction in endothelial marker CD34 immunostaining in representative sections, was observed following intralesional administration of anti-VEGFA siRNA-loaded peptide-based nanoparticles decorated with the cRGD ligand, compared to control ligand-free nanoparticles. Conclusions: The results provide evidence that electrostatically stabilized siRNA-peptide nanoparticles can exert anti-angiogenic effects in EM lesions following intralesional administration, warranting further investigation of their targeting properties, safety, and therapeutic potential.

Spinal muscular atrophy 5q (SMA) is the most common neuromuscular inherited disease in neonates which is associated with homozygous deletion of exon 7 in the SMN1 gene. Recently established drugs can improve the motor functions of SMA infants when treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using real-time PCR assay with dried blood spots (DBS) was performed in Saint-Petersburg from January 2022 through November 2022. Here, 36,140 newborns were screened by GenomeX real-time PCR-based screening test, and three genotypes were determined. Homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns) and wild-type individuals (35,364 newborns) were identified. All four newborns screened positive for homozygous SMN1 deletion were confirmed by alternate methods. Two of the newborns had two copies of SMN2, and two of the newborns had three copies. We determined Saint-Petersburg spinal muscular atrophy incidence of 1 in 9,035 and SMA carrier frequency of 1 in 47. In conclusion, it can be summarized that providing both timely SMN1 information and confirmation along with SMN2 copy number as part of SMA newborn screening algorithm can significantly improve clinical follow-up, family members testing, and SMA patients' treatment.