Hydrogels have many useful physicochemical properties which, in combination with their biocompatibility, suggest their application as a drug delivery system for the local and prorogated release of drugs. However, their drug-absorption capacity is limited because of the gel net’s poor adsorption of hydrophilic molecules and in particular, hydrophobic molecules. The absorption capacity of hydrogels can be increased with the incorporation of nanoparticles due to their huge surface area. In this review, composite hydrogels (physical, covalent and injectable) with included hydrophobic and hydrophilic nanoparticles are considered as suitable for use as carriers of anticancer chemotherapeutics. The main focus is given to the surface properties of the nanoparticles (hydrophilicity/hydrophobicity and surface electric charge) formed from metal and dielectric substances: metals (gold, silver), metal-oxides (iron, aluminum, titanium, zirconium), silicates (quartz) and carbon (graphene). The physicochemical properties of the nanoparticles are emphasized in order to assist researchers in choosing appropriate nanoparticles for the adsorption of drugs with hydrophilic and hydrophobic organic molecules.

This review discusses the literature data on the synthesis, physicochemical properties, and cytotoxicity of composite nanoparticles bearing the mitochondrial protein cytochrome c (cytC), which can act as a proapoptotic mediator in addition to its main function as an electron carrier in the electron transport chain. The introduction of exogenous cytC via absorption of carrier particles, the phagocytosis of colloid particles of submicrometric size, or the receptor-mediated endocytosis of nanoparticles in cancer cells, initiates the process of apoptosis—a multistage cascade of biochemical reactions leading to complete destruction of the cells. CytC–carrier composite particles have the potential for use in the treatment of neoplasms with superficial localization: skin, mouth, stomach, colon, etc. This approach can solve the two main problems of anticancer therapy: selectivity and non-toxicity. Selectivity is based on the incapability of the normal cell to absorb (nano)particles, except for the cells of the immune system. The use of cytC as a protein that normally functions in mitochondria is harmless for the macroorganism. In this review, the factors limiting cytotoxicity and the ways to increase it are discussed from the point of view of the physicochemical properties of the cytC–carrier particles. The different techniques used for the preparation of cytC-bearing colloids and nanoparticles are discussed. Articles reporting the achievement of high cytotoxicity with each of the techniques are critically analyzed.

The angiotensin-converting enzyme-2 (ACE2) is a transmembrane glycoprotein, consisting of two segments: a large carboxypeptidase catalytic domain and a small transmembrane collectrin-like segment. This protein plays an essential role in blood pressure regulation, transforming the peptides angiotensin-I and angiotensin-II (vasoconstrictors) into angiotensin-1-9 and angiotensin-1-7 (vasodilators). During the COVID-19 pandemic, ACE2 became best known as the receptor of the S-protein of SARS-CoV-2 coronavirus. The purpose of the following research is to reconstruct the 3D structure of the catalytic domain of the rabbit enzyme rACE2 using its primary amino acid sequence, and then to compare it with the human analog hACE2. For this purpose, we have calculated the electric properties and thermodynamic stability of the two protein globules employing computer programs for protein electrostatics. The analysis of the amino acid content and sequence demonstrates an 85% identity between the two polypeptide chains. The 3D alignment of the catalytic domains of the two enzymes shows coincidence of the α-helix segments, and a small difference in two unstructured segments of the chain. The electric charge of the catalytic domain of rACE2, determined by 70 positively chargeable amino acid residues, 114 negatively chargeable ones, and two positive charges of the Zn²⁺ atom in the active center exceeds that of hACE2 by one positively and four negatively chargeable groups; however, in 3D conformation, their isoelectric points pI 5.21 coincide. The surface electrostatic potential is similarly distributed on the surface of the two catalytic globules, but it strongly depends on the pH of the extracellular medium: it is almost positive at pH 5.0 but strongly negative at pH 7.4. The pH dependence of the electrostatic component of the free energy discloses that the 3D structure of the two enzymes is maximally stable at pH 6.5. The high similarity in the 3D structure, as well as in the electrostatic and thermodynamic properties, suggests that rabbit can be successfully used as an animal model to study blood pressure regulation and coronavirus infection, and the results can be extrapolated to humans.

Burnout is a syndrome that is increasingly common nowadays. It is associated with reduced work efficiency and chronic exhaustion. The main cause of burnout is continuous stress at work and not enough rest. The main system involved in the pathogenesis of burnout is the hypothalamic–pituitary–adrenocortical axis with the final substrate of the glucocorticoid hormone cortisol. Therefore, in patients with burnout syndrome, the morning plasma cortisol levels are elevated, but there is no significant change in its evening values. This correlates with an increase in blood pressure, weight gain, muscle weakness, low immunity, etc. The following case report is about the unusual effect of the antifungal drug itraconazole on the circadian rhythm of the plasma cortisol levels, as well as on the blood pressure in patient with burnout syndrome. One month of peroral application of 100 mg itraconazole every day reduces the morning plasma cortisol levels to the greatest extent (by approximately 37%) rather than the evening cortisol levels (by circa 17.5%). The decrease in the mean ambulatory systolic and diastolic blood pressure is also not uniform (it is stronger in diastolic – 27% than in systolic – 17%).

Background: Screening for presymptomatic type 1 diabetes (T1D) reduces the risk of diabetic ketoacidosis (DKA) and allows for early intervention with disease-modifying therapies. Despite the rising incidence of T1D in Bulgaria, screening initiatives remain limited. This pilot study aims to evaluate the feasibility of selective T1D screening in high-risk children and identify potential clinical associations with islet autoimmunity. Methods: The study targeted a recruitment of 250 children aged 0–18 years (200 with a relative with T1D and 50 without). Screening for islet autoantibodies (AABs), including glutamic acid decarboxylase (GADA), insulin (IAA), insulinoma-associated-2 (IA-2A), zinc transporter-8 (ZnT8A), and islet cell cytoplasmic autoantibodies (ICAs), was performed via chemiluminescence immunoassay (CLIA). Participants testing positive for one or more AABs were scheduled for longitudinal immunological and metabolic follow-up to evaluate the persistence of autoimmunity and disease progression. Results: Between October 2024 and February 2026, the pilot study recruited 210 participants (84% of the 250 target), including 160 children with a relative (target 200) and 50 without a family history of T1D (target 50). Within the high-risk group, seven children (4.4%) tested positive for a single autoantibody (3 GADA, 2 ZnT8A, 1 IA-2A, and 1 IAA), while no autoantibodies were detected in the group without a relative. No cases of multiple autoantibody positivity or stage 3 T1D were identified in either group. Furthermore, no statistically significant associations were observed between autoantibody positivity and secondary factors, including breastfeeding, allergic status, a high-glycemic diet, frequent illness, and personal history of autoimmune disease. Conclusions: The findings validate the feasibility of selective T1D screening in Bulgaria, driven by high public interest and successful recruitment across both high-risk and general population cohorts. While this exploratory study found no significant clinical correlations, it establishes a vital roadmap for larger, longitudinal research. Ultimately, this pilot framework provides a scalable model for implementing standardized early detection to reduce the burden of T1D on the national healthcare system.

Introduction and aim. Floating-Harbor syndrome (FHS) is a very rare disease, whose typical characteristics include short stature, facial dysmorphic features and significant speech delay. We aim to present the first reported case of FHS with discordant growth hormone tests and confirmed hypoplasia of the pituitary gland. Description of the case. We report a case of a boy aged 8 years and 3 months with a height constantly below the 3rd percentile, delayed bone age in comparison to chronological age, typical dysmorphic triangular face and a high-pitched voice. Whole-exome sequencing (WES) detected a heterozygous pathogenic variant in SRCAP gene – a confirmation of the diagnosis Floating-Harbor syndrome (FHS). Recombinant human growth hormone (rhGH) therapy at a dose of 0.033 mg/kg/day (0.65 mg/day) was initiated at the age of 7 years and 10 months. Because of the insufficient growth velocity at the time of manuscript preparation a dose increase was made to 0.035 mg/kg/day (0.80 mg/day). Conclusion. In children presenting with short stature (especially when GH deficiency is confirmed), facial dysmorphism and developmental delay, Floating-Harbor syndrome should be considered as a possible diagnosis. A multidisciplinary approach involving pediatric endocrinologists, geneticists and developmental specialists is essential for timely etiological diagnosis and optimal management.