Cationic amino-acid functionalized polymethacrylamide vectors for siRNA transfection based on modification of poly(2-isopropenyl-2-oxazoline)

Poly(2-isopropenyl-2-oxazoline) (PiPOx) is a functional polymer showing great potential for the development of smart biomaterials. The straightforward synthesis and post-polymerization functionalization of PiPOx offers many opportunities for tailoring the properties of the polymer towards biomaterials. In this study we report for the first time PiPOx-based cationic charged polymethacrylamides with amino acid side chains that can complex siRNA and promote transfection in vitro. Therefore, PiPOx was fully modified via ring opening addition reactions with the carboxylic acid groups of a series of N-Boc-L-amino acids and their reaction kinetics were investigated. Based on the determined kinetic constants, another series of PiPOx-based copolymers with balanced hydrophilic/hydrophobic content of N-Boc-L-amino acids were obtained via one-pot modification reaction with two different N-Boc-L-amino acids. The N-Boc protected homopolymers and related copolymers were deprotected to obtain (co)polymers with the targeted side chain cationic charged units. The (co)polymers' structures were fully investigated via FT-IR and 1H NMR spectroscopy, size exclusion chromatography (SEC), and TGA-DSC-MS analysis. The polarimetry measurements revealed that the homopolymers retain their chiroptical properties after post-modification, and a sign inversion is noticed from (L) N-Boc-protected analogues to (D) for the TFA cationic charged homopolymers. Generally, cationically charged homopolymers with hydrophilic amino acids on the side chain showed efficient complexation of siRNA, but poor transfection while cationic copolymers having both tryptophan and valine or proline side chains revealed moderate siRNA binding, high transfection efficiency (> 90% of the cells) and potent gene silencing with IC50 values down to 5.5 nM. Particularly, these cationic copolymers showed higher gene silencing potency as compared to the commercial JetPRIME® reference, without reducing cell viability in the concentration range used for transfection, making this a very interesting system for in vitro siRNA transfection.

The alpha-adrenergic antagonist prazosin promotes cytosolic siRNA delivery from lysosomal compartments

The widespread use of small interfering RNA (siRNA) is limited by the multiple extra- and intracellular barriers upon in vivo administration. Hence, suitable delivery systems, based on siRNA encapsulation in nanoparticles or its conjugation to targeting ligands, have been developed. Nevertheless, at the intracellular level, these state-of-the-art delivery systems still suffer from a low endosomal escape efficiency. Consequently, the bulk of the endocytosed siRNA drug rapidly accumulates in the lysosomal compartment. We recently reported that a wide variety of cationic amphiphilic drugs (CADs) can promote small nucleic acid delivery from the endolysosomal compartment into the cytosol via transient induction of lysosomal membrane permeabilization. Here, we describe the identification of alternate siRNA delivery enhancers from the NIH Clinical Compound Collection that do not have the typical physicochemical properties of CADs. Additionally, we demonstrate improved endolysosomal escape of siRNA via a cholesterol conjugate and polymeric carriers with the α1-adrenergic antagonist prazosin, which was identified as the best performing delivery enhancer from the compound screen. A more detailed assessment of the mode-of-action of prazosin suggests that a different cellular phenotype compared to typical CAD adjuvants drives cytosolic siRNA delivery. As it has been described in the literature that prazosin also induces cancer cell apoptosis and promotes antigen cross-presentation in dendritic cells, the proof-of-concept data in this work provides opportunities for the repurposing of prazosin in an anti-cancer combination strategy with siRNA.

Repositioning the antihistamine ebastine as an intracellular siRNA delivery enhancer

Small interfering RNAs (siRNAs) are promising therapeutics for the treatment of human diseases via the induction of sequence-specific gene silencing. To be functional, siRNAs require cytosolic delivery into target cells. However, state-of-the-art delivery systems mediate cellular entry through endocytosis and suffer from ineffective endosomal escape, routing a substantial fraction of the siRNA towards the lysosomal compartment. Cationic amphiphilic drugs (CADs) have been described to improve cytosolic siRNA delivery by the transient induction of lysosomal membrane permeabilization. In this work, we evaluated ebastine, an antihistamine CAD, for its ability to enhance cytosolic release of siRNA in a non-small cell lung cancer model. In particular, we demonstrated that ebastine can improve the siRNA-mediated gene silencing efficiency of a polymeric nanogel by 40-fold, outperforming other CAD compounds. Additionally, ebastine substantially enhanced gene knockdown of a cholesterol-conjugated siRNA, in two-dimensional (2D) cell culture as well as in three-dimensional (3D) tumor spheroids. Finally, ebastine could strongly promote siRNA delivery of lipid nanoparticles (LNPs) composed of a pH-dependent switchable ionizable lipid and with stable PEGylation, in contrast to state-of-the-art LNP formulations. Altogether, we identified ebastine as a potent and versatile siRNA delivery enhancer in cancer cells, which offers opportunities for drug combination therapy in oncology.

Influence of the Size and Charge of Carbon Quantum Dots on Their Corneal Penetration and Permeation Enhancing Properties

Reaching the corneal endothelium through the topical administration of therapeutic drugs remains a challenge in ophthalmology. Besides, endothelial cells are not able to regenerate, and diseases at this site can lead to corneal blindness. Targeting the corneal endothelium implies efficient penetration through the three corneal layers, which still remains difficult for small molecules. Carbon quantum dots (CQDs) have demonstrated great potential for ocular nanomedicine. This study focuses on the corneal penetration abilities of differently charged CQDs and their use as permeation enhancers for drugs. Excised whole bovine eyes were used as an ex vivo model to investigate corneal penetration of CQDs derived from glucosamine using β-alanine, ethylenediamine, or spermidine as a passivation agent. It was found that negatively charged CQDs have limited corneal penetration ability, while positively charged CQDs derived from glucosamine hydrochloride and spermidine (CQD-S) penetrate the entire corneal epithelium all the way down to the endothelium. CQD-S were shown to enhance the penetration of FITC-dextran 150 kDa, suggesting that they could be used as efficient penetration enhancers for therapeutic delivery to the corneal endothelium.

A lipid nanoparticle platform for mRNA delivery through repurposing of cationic amphiphilic drugs

Since the recent clinical approval of siRNA-based drugs and COVID-19 mRNA vaccines, the potential of RNA therapeutics for patient healthcare has become widely accepted. Lipid nanoparticles (LNPs) are currently the most advanced nanocarriers for RNA packaging and delivery. Nevertheless, the intracellular delivery efficiency of state-of-the-art LNPs remains relatively low and safety and immunogenicity concerns with synthetic lipid components persist, altogether rationalizing the exploration of alternative LNP compositions. In addition, there is an interest in exploiting LNP technology for simultaneous encapsulation of small molecule drugs and RNA in a single nanocarrier. Here, we describe how well-known tricyclic cationic amphiphilic drugs (CADs) can be repurposed as both structural and functional components of lipid-based NPs for mRNA formulation, further referred to as CADosomes. We demonstrate that selected CADs, such as tricyclic antidepressants and antihistamines, self-assemble with the widely-used helper lipid DOPE to form cationic lipid vesicles for subsequent mRNA complexation and delivery, without the need for prior lipophilic derivatization. Selected CADosomes enabled efficient mRNA delivery in various in vitro cell models, including easy-to-transfect cancer cells (e.g. human cervical carcinoma HeLa cell line) as well as hard-to-transfect primary cells (e.g. primary bovine corneal epithelial cells), outperforming commercially available cationic liposomes and state-of-the-art LNPs. In addition, using the antidepressant nortriptyline as a model compound, we show that CADs can maintain their pharmacological activity upon CADosome incorporation. Furthermore, in vivo proof-of-concept was obtained, demonstrating CADosome-mediated mRNA delivery in the corneal epithelial cells of rabbit eyes, which could pave the way for future applications in ophthalmology. Based on our results, the co-formulation of CADs, helper lipids and mRNA into lipid-based nanocarriers is proposed as a versatile and straightforward approach for the rational development of drug combination therapies.

Efficiency of Michigan Neuropathy Screening Instrument and Nerve Conduction Studies for Diagnosis of Diabetic Distal Symmetric Polyneuropathy

Background and Aims: Little data regarding distal symmetric polyneuropathy (DSP) prevalence in Romania is available. The aim of the present study was to assess the prevalence of DSP in our cohort, to characterize it depending on glycemic control, and also to find an easy-to-apply method for DSP screening which could be used in Romania.

Material and Methods: We performed a cross-sectional study enrolling 51 patients followed in the Diabetes, Nutrition and Metabolic Diseases Clinic, Clinical County Hospital of Craiova, Romania. A complete evaluation protocol consisting in clinical examination and Michigan Neuropathy Screening Instrument (MNSI), together with nerve conduction studies were applied for evaluation.

Results: Among the type 2 diabetic patients investigated, 72.54% had DSP. Three-quarters of them had poor glycemic control (HbA1c ≥7%). Mean HbA1c level was 9.17%. Poor glycemic control led to a more severe DSP form as proven by nerve conduction studies and clinical examination. Allodynia and motor deficit were predominantly found with HbA1c ≥7%. Mean MNSI score for the group was 2.55, strongly correlated with nerve conduction studies.

Conclusion: MNSI is a simple and validated diagnostic tool for DSP with a strong correlation to electrophysiological parameters. Therefore, its daily implementation in clinical practice could help identify and follow patients at risk for DSP.

Immunotherapy in Peripheral Neuropathies

Immunotherapy has been investigated in a small subset of peripheral neuropathies, including an acute one, Guillain-Barré syndrome, and 3 chronic forms: chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and neuropathy associated with IgM anti-myelin-associated glycoprotein. Several experimental studies and clinical data are strongly suggestive of an immune-mediated pathogenesis. Either cell-mediated mechanisms or antibody responses to Schwann cell, compact myelin, or nodal antigens are considered to act together in an aberrant immune response to cause damage to peripheral nerves. Immunomodulatory treatments used in these neuropathies aim to act at various steps of this pathogenic process. However, there are many phenotypic variants and, consequently, there is a significant difference in the response to immunotherapy between these neuropathies, as well as a need to improve our knowledge and long-term management of chronic forms.

Characterization of the relations between morphology and physiological status of the pineal gland in connection with the somatic development level in turkeys reared in Romania

This research started from the premises of the existence of some possible relationships between indole and pineal peptide hormones and the somatic development, with participation of hypothalamic-pituitary complex. Experimental factors, which were the subject of the present paper, influenced the dynamics of corporal mass and fodder consumption, leading to the occurrence of some important structural modifications at the level of pineal gland. The exposure of the individuals to continuous light (photic pinealectomy) produces increases in corporal mass, showing the involvement of the pineal gland in neuro-endocrine-metabolic reactions, which contributes to the maintenance of homeostatic balance, including somatic ones. Biological material was represented by a number of 50 individuals belonging to B.U.T. Big 6 hybrid, reared on soil, on a permanent litter, which could assure the expanding of knowledge area regarding the relation between rearing technology, modulation of some microclimate parameters and growing performances. Were also realised cytometric and hystometric muscular determinations.

[Cardiac arrest outside hospital: initial and subsequent cardiological management]

The prognosis of cardiac arrest outside hospital is directly related to the initial management. The aim of this work was to evaluate the characteristics of the initial and subsequent cardiological management of victims of cardiac arrest outside hospital with a retrospective analysis of data from the SAMU 35 (Emergency Medical Service, IIIe et Vilaine region) in the period April 1998 - April 2002.

RESULTS

533 non-traumatic cardiac arrests outside hospital were reported in 532 patients (average age 63 +/- 17, 73% male). The cardiac arrest occurred at home in 77% of cases. The initial cardiac rhythm documented was asystole in 63% of cases, ventricular fibrillation (VF) in 30% ventricular tachycardia (VT) in 1% and electromechanical dissociation in 6%. A cardiac aetiology was presumed in 294 (69%) of the 424 resuscitated patients. Among these, 22% (66/294) were admitted to coronary care units, 11% (31) left hospital alive, 8% (24) with no neurological sequelae. The survival rate for patients with cardiac arrest outside hospital in the presence of a witness and for whom the initial rhythm was VF or VT was 21%. The patient's age (<60 years)[OR: 1.05; CI 95%: 1.02-1.07; p < 0.001], rapid arrival of the SAMU (<10 min) [OR: 5.68; CI 95%: 1.42-22.7; p = 0.01] and resuscitation by the witness (OR: 8.26; CI 95%: 3.28-20.83; p < 0.001) were factors predictive of survival in a multivariate analysis. Coronary heart disease remains the principal cause of cardiac arrest in patients admitted to cardiology units (68%), with a recent coronary thrombosis shown in 40% of patients undergoing angiography (16/40).

CONCLUSION

the prognosis of cardiac arrest outside hospital remains bleak, with a mortality of 90%. The survival rate is higher if the initial management is optimal, associated with bystander resuscitation and an immediate emergency service response allowing rapid defibrillation. Diagnosis and management of acute coronary syndrome in a cardiological setting must be integrated into the strategy.

[Intracerebral haematoma during a stress test]

We report the case of a 64 year-old moderately hypertensive patient investigated for dyspnoea on exertion with no chest pain. After informing the patient, an ergometric test following a gentle protocol was performed, according to the French Society of Cardiology guidelines. At the peak of effort the patient developed a sudden left hemiplegia with a right capsulo-thalamic haematoma on cranial CT. No other case has been described and a literature search showed no relationship between physical effort and cerebral haematoma. Following an administrative tribunal enquiry, no medical fault was attributed regarding the indication and performing the test; no failure to inform could be established for a risk that was unknown at the time of the test.

[Sudden death disclosing abnormal origin of the left coronary vessel from the pulmonary artery trunk]

Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital abnormality with a poor prognosis in the newborn. Adult forms are, therefore, very rare, presenting with angina, cardiac failure or sudden death. The authors report the case of a 41 year old woman who was asymptomatic until admitted as an emergency after ventricular fibrillation. Coronary angiography established the diagnosis. Despite the absence of reversible ischaemia on exercise myocardial scintigraphy, the patient underwent coronary bypass surgery of the left anterior descending artery with a pediculated internal mammary artery graft and closure of the left coronary ostium on the pulmonary artery. The echocardiographic abnormalities regressed within a few weeks. An automatic defibrillator was not implanted. The physiopathology of this rare cardiac lesion, the mechanisms of sudden death and the different techniques of surgical repair are discussed.

The expression of p53 protein in salivary gland carcinomas

The p53 suppressor gene is the most frequently altered gene in solid human malignancies. It is located on the short arm of chromosome 17 in the region 17p13 and encodes a 53kD nuclear phosphoprotein containing 393 amino acids with specific DNA binding properties and a short life span. The wild p53 protein has been classified as a tumoral suppression gene with a determining role in controlling cellular proliferation and differentiation and can be inactivated through mutation in the protein sequence encoding the gene, leading to neoplastic transformation. In this study we analyzed the expression of p53 protein in a variety of salivary gland malignant tumors fixed in formalin and included in paraffin, using the method of immunohistochemical coloring with the anti-p53 DO-7 antibody. The evaluation of the immunoreactivity with p53 proved a significantly more intense coloring in salivary gland high-grade malignant tumors and the observed immunomarking of over 50% of the tumoral cells is correlated with the weak differentiation of the tumors, giving a predictive factor for the evolution of the disease.