Biological Materials Research Articles

Current State and Challenges of Tissue and Organ Cryopreservation in Biobanking

Recent years have witnessed significant advancements in the cryopreservation of various tissues and cells, yet several challenges persist. This review evaluates the current state of cryopreservation, focusing on contemporary methods, notable achievements, and ongoing difficulties. Techniques such as slow freezing and vitrification have enabled the successful preservation of diverse biological materials, including embryos and ovarian tissue, marking substantial progress in reproductive medicine and regenerative therapies. These achievements highlight improved post-thaw survival and functionality of cryopreserved samples. However, there are remaining challenges such as ice crystal formation, which can lead to cell damage, and the cryopreservation of larger, more complex tissues and organs. This review also explores the role of cryoprotectants and the importance of optimizing both cooling and warming rates to enhance preservation outcomes. Future research priorities include developing new cryoprotective agents, elucidating the mechanisms of cryoinjury, and refining protocols for preserving complex tissues and organs. This comprehensive overview underscores the transformative potential of cryopreservation in biomedicine, while emphasizing the necessity for ongoing innovation to address existing challenges.

Modern developments in lasing with liquid crystals

A review of the recent developments in the field of lasing with liquid crystals (LCs) is presented. After an introduction into the principle of lasing the different relevant liquid crystal phases to the field are introduced, namely, the nematic and chiral nematic phase, Blue Phases, twist grain boundary and ferroelectric liquid crystals. The classic examples of liquid crystal lasing are shortly discussed, together with a variety of possibilities for tuning the lasing wavelength, before the modern trends in LC lasing are discussed in detail. These are particularly random lasers, where the effects of nanoparticles, quantum dots and solitons are highlighted, as well as localized surface plasmon resonance. Other modern laser systems that have attracted recent interest, white lasers, whispering gallery mode lasers and those with biological materials, for example, cellulose nanocrystals, are also introduced and the latest developments outlined.

Cellular solids and prestressed affine networks as models of the elastic behavior of soft biological structures.

We reviewed two microstructural models, cellular solid models and prestressed affine network models, that have been used previously in studies of elastic behavior of soft biological materials. These models provide simple and mathematically transparent equations that can be used to interpret experimental data and to obtain quantitative predictions of the elastic properties of biological structures. In both models, volumetric density and elastic properties of the microstructure are key determinants of the macroscopic elastic properties. In the prestressed network model, geometrical rearrangement of the microstructure (kinematic stiffness) is also important. As examples of application of these models, we considered the shear behavior of the cytoskeleton of adherent cells, of the collagen network of articular cartilage, and of the lung parenchymal network since their ability to resist shear is important for their normal biological and physiological functions. All three networks carry a pre-existing stress (prestress). We predicted their shear moduli using the microstructural models and compared those predictions with existing experimental data. Prestressed network models of the cytoskeleton and of the lung parenchyma provided a better correspondence to experimental data than cellular solid models. Both cellular solid and prestressed network models of the cartilage collagen network provided reasonable agreements with experimental values. These findings suggested that the kinematic stiffness and material stiffness of microstructural elements were both important determinants of the shear modulus of the cytoskeleton and of the lung parenchyma, whereas elasticity of collagen fibrils had a predominant role in the cartilage shear behavior.

STUDY OF THE ENDOMETRIAL GLANDULAR COMPONENT IN WOMEN WITH FERTILITY AND POST-COVID SYNDROME IN ANAMNESIS

The aim. To increase the effectiveness of the endometrial endometrial glandular component study in women with infertility and post-COVID syndrome. Materials and methods. A study was conducted at the State institution "Carpathian Human Reproduction Centre" of the Ministry of Health of Ukraine in the period from 2022 to the end of the first half-year of 2024. There were included 80 women in the experimental group and 40 women in the control group. The selection criterion for the study group was the presence of documented post-COVID syndrome (COVID-19 symptoms lasted longer than 12 weeks). The selection criterion for the control group was the absence of confirmed SARS-CoV-2 virus in the anamnesis. The following characteristics were common for both groups: diagnosed infertility, age – 25-42 years, written informed consent of the patient to participate in the study. The criteria for exclusion from the study for patients of both groups were: detection of human immunodeficiency virus, viral hepatitis, other sexually transmitted infections, tuberculosis of the genitourinary system, malignant diseases, mental disorders that make communication with person impossible or the awareness of written consent is questioned. General clinical and laboratory examinations and transvaginal sonographic examination of the pelvic organs were performed in the middle stage of proliferation and the middle stage of secretion according to the calendar calculation the menstrual cycle. A visually guided diagnostic office hysteroscopy was performed with the collection of biological material from the most changed areas (biopsies were collected in the middle stage of proliferation and the middle stage of secretion in different menstrual cycles). A routine staining of samples with hematoxylin-eosin, morphometry of the endometrial glandular component, optical determination of the number of glands and measurement of the diameter of the lumen of the studied glands, considering the possible measurement error, glandular-stromal ratio, functional activity of the glands, were performed. A histochemical PAS-reaction to identify the glycoproteins of gland secretions and immunohistochemical staining of the glandular epithelium to express the receptivity of the glands to estrogen and progesterone were carried out. The results. After conducting the PAS-reaction, a higher secretion was noted in the glands than in the stroma of the endometrium during the period of the implantation window in both cohorts. No statistically significant difference between the groups in the amount of glycogen of the middle proliferative phase in the glands (p=0.315) or stroma (p=0.486). Glycogen in this phase was visualized of very small granules and coarse granules, without their formation in clusters. A decrease in secretion was established in 16 (40%) patients of the control group and 49 (61.3%) women of the experimental group in the middle secretory phase, which was statistically significant (p=0.028). A decrease in the expression level of the progesterone receptor in the middle secretory phase was found to be significantly more pronounced in the experimental group than in the control group (р=0.044). Conclusions. In the middle secretory phase, a decrease in the secretion of glycogen by the endometrial glands and a decrease in the level of expression of the progesterone receptor in endometrial biopsies were detected by the routine histological, histochemical techniques and immunohistochemical stude in women with infertility and a history of post-COVID syndrome.

Pilot Study on the Effect of Patient Condition and Clinical Parameters on Hypoxia-Induced Factor Expression: HIF1A, EPAS1 and HIF3A in Human Colostrum Cells.

Hypoxia-inducible factor 1 (HIF-1) may play a role in mammary gland development, milk production and secretion in mammals. Due to the limited number of scientific reports on the expression of HIF genes in colostrum cells, it was decided to examine the expression of HIF1A, HIF3A and EPAS1 in the these cells, collected from 35 patients who voluntarily agreed to provide their biological material for research, were informed about the purpose of the study and signed a consent to participate in it. The expression of HIF genes was assessed using qPCR. Additionally, the influence of clinical parameters (method of delivery, occurrence of stillbirths in previous pregnancies, BMI level before pregnancy and at the moment of delivery, presence of hypertension during pregnancy, presence of Escherichia coli in vaginal culture, iron supplement and heparin intake during pregnancy) on the gene expression was assessed, revealing statistically significant correlations. The expression of HIF1A was 3.5-fold higher in the case of patients with the presence of E. coli in vaginal culture (p = 0.041) and 2.5 times higher (p = 0.031) in samples from women who used heparin during pregnancy. Approximately 1.7-fold higher expression of the EPAS1 was observed in women who did not supplement iron during pregnancy (p = 0.046). To our knowledge, these are the first studies showing the relationship between HIF expression in cells from breast milk and the method of delivery and health condition of women giving birth. The assessment of HIF expression requires deeper examination in a larger study group, and the results of further studies will allow to determine whether HIF can become biomarkers in pregnancy pathology states.

A Significant Correlation of Glutamine and Interlukin-6 with Pregnancy Rate in Women Undergoing ICSI

Background: The composition of follicular fluid (FF) is significantly influenced by metabolic factors, and the analyses of metabolites in FF could reveal the correlation between metabolites and oocyte quality, embryo development, and pregnancy outcome. FF provides nutrients and growth factors that promote oocyte growth, development, and maturation. Objective: To investigate the relationship between serum and FF glutamine and FF IL-6 levels and their influence on the pregnancy rate in women who are undergoing an ICSI treatment cycle. Materials and Methods: A prospective cross-sectional study was performed on 90 women aged 20- 44 years who underwent ICSI treatment from July 2023 to February 2024. Serum and follicular fluid collected on the day of oocyte pick-up were used as biological material. The embryological laboratory examined the retrieved follicular fluid and collected oocytes using stereomicroscopy. ELISA analysed serum, FF glutamine and FF IL-6. The ICSI method was utilized for fertilization. The pregnancy test is done by measuring serum BHCG. Statistical data processing was conducted using the software package SPSS 23. Results: There was a highly significant correlation between FF glutamine and FF IL-6 (p < 0.001) and a positive correlation between FF glutamine and FF IL-6 with pregnancy rate ( p < 0.001) (p < 0.001 ). Conclusion The correlation of FF glutamine and FF IL-6 affects the pregnancy rate in women undergoing ICSI. FF glutamine and FF IL-6 can be considered predictors for pregnancy while serum glutamine has no significance.

Age and gender related changes on total antioxidant/oxidant status and electrolyte composition of saliva

BackgroundSaliva is used as an important biological material in the diagnosis and treatment of various diseases to collect easily, to be cheap, to have a minimal risk of infection. Here in that study we aimed to evaluate age and gender-related changes on total antioxidant/oxidant status and electrolyte composition of saliva levels in individuals. MethodsA total of 30 young adult (21.2 ± 2.47 years) and 14 adult (51.6 ± 9.35 years) subjects were included in the study. Stimulated saliva samples were collected. Cortisol, amylase, oxidative stress biomarkers (total antioxidant status and total oxidant status) were measured by ELISA and spectrophotometric manual methods and electrolyte level of saliva samples were determined by autoanalyzer. ResultsSalivary concentrations of biomarkers of young adults were compared to adult subjects, there was a statistically significant difference between cortisol (μg/dL) (p = 0.003), Ca+2(mg/dL) (p = 0.004), TAS (mmol Trolox Equiv/L) (p = 0.001), BUN (mg/dL) (p = 0.02), Mg+2 (mg/dL) (p = 0.02), and K+ (mmol/L) (p = 0.05) levels, but there was no significant difference was found between uric acid (mg/dL) (p = 0.44), Cl- (mmol/L) (p = 0.07), amylase (ng/mL) (p = 0.47), phosphate (mg/dL) (p = 0.63), Na+(mmol/L)(p = 0.21), and TOS (μmol H2O2 Equiv/L) (p = 0.70) levels. We evaluated salivary cortisol, amylase, and electrolyte levels of groups that we commented on their relationship between oxidant-antioxidant defense systems of the saliva and their correlations with age and gender. ConclusionsThis study could suggest the use of saliva samples to correlate with age and representing the levels of the most common biological parameters for routine use and antioxidant-oxidant enzymes for clinical trials.

Investigation and Demonstration for immunoassay technology based on impedance Amplifies of magnetic and dielectric microbeads

BackgroundBead-based immunoassays typically require researchers to perform the analysis in a laboratory setting, involving complex processing procedures, most of the time, constant potential or current instruments are used to measure the bio-impedance change. However, almost all biological materials are decorated on the electrode surface to obtain the maximum sensitivity, resulting in difficulty to clean, separate, and other applications of fixed bead-based immunoassay. ResultWe present an innovative unfixed bead-based immunoassay technology that utilizes electrical impedance characteristics, offering the advantages of being rapid, portable, miniaturized, and cost-effective. This technique which is known as Impedance-enhanced electrochemical immunoassay (IE-ECIA) employs antibody-coated Magnetic beads (MBs) and Dielectric beads (DBs) linked to antigens for quantitative with miniaturization electronic devices, which has been successfully applied in an immune impedance sensor for detecting the Dengue virus (DENV), which is an affordable test with a low-cost microfluidic impedance biosensor combined with immune magnetic and dielectric micro/nanobeads for antigen detection. HighlightThe proposed immunoassay technology introduces a novel microfluidic platform incorporating magnetic and dielectric beads alongside with an electrochemical impedance biosensor, therefore facilitating continuous-fluid quantitative analysis. This innovative and unconventional approach leverages free-motion multiplex beads housing magnetic and dielectric bead-bound antigens within a simple linear microchannel of microfluidic chip architecture, making the high-through measurements more efficient, enhanced Electrochemical immunoassay (ECIA) signals of Bio-on-magnetic-beads (BOMB). This advancement holds significant potential for enhancing diagnostic capabilities for emerging infectious diseases within clinical environments, thereby bolstering rapid detection capabilities and aiding in the advancement of novel pharmaceuticals, benefiting all the stakeholders.

Quantum Molecular Charge-Transfer Model for Multistep Auger-Meitner Decay Cascade Dynamics.

The fragmentation of molecular cations following inner-shell decay processes in molecules containing heavy elements underpins the X-ray damage effects observed in X-ray scattering measurements of biological and chemical materials, as well as in medical applications involving Auger electron-emitting radionuclides. Traditionally, these processes are modeled using simulations that describe the electronic structure at an atomic level, thereby omitting molecular bonding effects. This work addresses the gap by introducing a novel approach that couples Auger-Meitner decay to nuclear dynamics across multiple decay steps, by developing a decay spawning dynamics algorithm and applying it to potential energy surfaces characterized with ab initio molecular dynamics simulations. We showcase the approach on a model decay cascade following K-shell ionization of IBr and subsequent Kβ fluorescence decay. We examine two competing channels that undergo two decay steps, resulting in ion pairs with a total 3+ charge state. This approach provides a continuous description of the electron transfer dynamics occurring during the multistep decay cascade and molecular fragmentation, revealing the combined inner-shell decay and charge transfer time scale to be approximately 75 fs. Our computed kinetic energies of ion fragments show good agreement with experimental data.

Macroscopic and microscopic investigations of determining elasto-mechanical properties of limequat fruit.

Given the paramount importance of agricultural products in global health and food security, and the increasing consumer demand, understanding the mechanical behavior of these materials under various conditions is necessary yet challenging. Due to their heterogeneous and non-uniform nature, determining their mechanical behavior is complex. This study employs atomic force microscopy (AFM) to determine the modulus of elasticity of limequat fruit at the microscopic scale and compares it with macroscopic methods. The analyses revealed a statistically significant difference (at the 1% level) in the mechanical behavior determined at the macroscopic scale. The highest modulus of elasticity, 0.752 MPa, was observed using Hertz's theory under complete placement between two parallel planes. The lowest, 0.059 MPa, was noted when a spherical probe compressed a rectangular sample. The average modulus of elasticity of the limequat peel was 2.007 MPa. At the microscopic scale, the modulus of elasticity of the fruit tissue ranged from 0.370 to 0.365 MPa, and for the peel, it was 0.246 MPa. RESEARCH HIGHLIGHTS: Working principles of this innovative technique were elaborated. The AFM technique used provide elasto-mechanical properties determination of cell walls of single living cells extracted from biological materials on the nanoscale. By combining AFM topographical image and nano-indentation of living fruit cells it will be possible to investigate cells' elasto-mechanical properties. Atomic force microscopy holds great potential for monitoring fruit mechanical properties of biological materials.

The Efficacy of Orange Terpene and Bacillus mycoides Strain BM103 on the Control of Periwinkle Leaf Yellowing Phytoplasma.

Phytoplasmas are obligate phytopathogenic bacteria belonging to the class Mollicutes. The pathogens, transmitted by insect vectors, associated with hundreds of plant diseases worldwide. Due to the regulation on banning use of antibiotics and limited efficacy of the traditional disease management manners, an eco-friendly alternative is needed. Given that terpene and probiotics have antibiotic activity and the ability to induce systemic resistance, in this study, the effectiveness of orange terpene and a Bacillus mycoides strain, BM103, was evaluated in periwinkle plants infected with periwinkle leaf yellowing (PLY) phytoplasma derived from a shoot-tip tissue culture system. Weekly drenching of 1,000 ppm diluted orange terpene emulsion or pre-activated strain BM103 liquid culture dilution exhibited the ability to inhibit PLY phytoplasma accumulation. The expression of the genes associated with plant defense response and flower development was upregulated after treatment. Moreover, pre-treatment of orange terpene or strain BM103 delayed PLY infection via cleft-grafting inoculation. While orange terpene did not suppress the symptoms, strain BM103 did result in a milder symptom expression that might partially attribute to its plant growth-promoting characteristics. Additionally, the pre-activation of strain BM103 may contribute to its efficacy. Taken together, this research indicates that orange terpene and B. mycoides BM103, with the ability to rapidly induce plant defense responses, could potentially be developed into biological control materials as preventive agents or biofertilizers.

Morphological and Autofluorescence Dataset for ‘Touch’ Epidermal Cell Populations Collected with Imaging Flow Cytometry

Background New methods for processing ‘touch’ or trace biological samples is an ongoing priority for forensic caseworking laboratories. These samples often contain materials from multiple individuals in varying quantities and/or degrees of degradation. Rapid characterization of cellular material before DNA profiling can allow laboratories to screen samples for the presence of multiple contributors or the amount of biological material present. Methods This dataset contains autofluorescence and morphological profiles of epidermal cell populations analyzed using Imaging Flow Cytometry. The epidermal samples were aged for varying amounts of time prior to analysis. Multiple samples from the same individual were also collected to assess profile variations within and across the contributors. Conclusions This data set may be used to investigate variability in epidermal cell populations from different individuals and potential forensic signatures contained within the non-genetic components that comprise touch biological evidence.

Anatomical and Computed Tomography Study of the Mandible of the Patagonian Huemul (Hippocamelus bisulcus): Ecological and Clinical Insights.

Given the high prevalence of skeletal and mandibular diseases in the Patagonian Huemul, comprehensive anatomical studies are essential to understand the impact of nutritional deficiencies and support conservation efforts. The aim of this study is to provide a detailed anatomical characterisation of three exhumed mandibles of Patagonian huemul (Hippocamelus bisulcus) through three-dimensional reconstructions obtained from computed tomography data and semi-automatic segmentation, documenting their distinctive features. The findings revealed distinctive features in the mandible, consistent with the browsing habits of herbivores, such as a robust coronoid process, a wide and deep pterygoid fossa, a significantly lower mandibular condyle compared to other deer species and a unique configuration of the mandibular canal with a curved caudal portion and a straight rostral portion. These anatomical adaptations are likely related to the species' feeding habits and behaviour. The study also addressed the challenges of researching an endangered species, given that access to biological material is restricted by strict regulations in Chile and Argentina. These restrictions limited the available sample size and hindered the acquisition of additional specimens, which could affect the generalisation of the results. Despite these limitations, the research provides valuable anatomical insights that are fundamental for the biology, clinical practice and management of specimens. In conclusion, the mandibles of both juvenile and adult Patagonian huemul demonstrate distinctive features characteristic of browsing herbivores. The findings can serve as a basis for future comparative studies on mandibular anatomy and function in this endangered deer species as well as in other herbivorous deer.

Advancing early detection of biological events by digital holographic microscopy and simulation of microorganisms

There is a global need to advance bio-aerosol sensing for CBRN (Chemical, Biological, Radiological, and Nuclear) applications by compact and cost-effective devices. Employing digital holographic microscopy (DHM) and deep learning, we developed a system called HoloZcan to automate the analysis of airborne microbial pathogens and particles. DHM provides valuable information, but obtaining data from biological specimens for robust investigations is challenging. This paper introduces a custom simulation approach using the open-source software Meep and the finite-difference time-domain (FDTD) method to overcome limitations of existing Mie-based simulators, especially when dealing with complex microbial shapes. The simulation tool enables the modelling of specific microorganisms, offering a safer and more flexible alternative for CBRN research by bypassing ethical and logistical constraints associated with live pathogens. The study details the simulation workflow, built upon the construction of a database of optical properties of biological materials, for realistic simulations of light-microbe interactions. Evaluations on homogeneous and non-homogeneous objects demonstrate the tool’s limited intrinsic errors and superior sensitivity to refractive index changes compared to traditional Mie-based simulations. This work significantly advances our capability to accurately simulate and analyse CBRN-related scenarios, enhancing comprehensive research in bio-aerosol sensing.Graphical abstract

Contact zone of European (Meles meles Linnaeus, 1758) and Asian (M. leucurus Hodgson, 1847) badgers (Mustelidae, Mammalia) in the rightand left-bank districts of the Saratov region

DNA studies of badgers (Meles sp.) from the right-bank and left-bank areas of the Volga river in the Saratov region are described. Asian badgers (Meles leucurus Hodgson, 1847) inhabit the Left Volga Bank of the Saratov region, while European badgers (M. meles Linnaeus, 1758) inhabit the Right Volga Bank districts of the region, but Asian badgers were found in Khvalynsky district of the Saratov region, besides the European badger. Despite a sufficient number of publications devoted to the Asiatic badger distribution in the Vyatka–Kama region and the Volga region, and studies devoted to the development of systematics of the genus Meles in Russia, the question of the boundaries of the ranges of European and Asiatic badgers and the zones of their sympatry (parapatry) in the Volga–Kama region has not been fully investigated to date. Our work is devoted to the study of this question. As a result of analyzing the biological material collected by us, it was found that all five studied individuals of badgers from the Saratov Volga region phenotypically looked like Asian badgers, but our DNA analysis showed that only two of them were M. leucurus, whilst three ones were heterozygous individuals carrying genes from both species and were identified as hybrids. The remaining 29 individuals were captured in the right-bank areas of the region. Badgers were sampled from individuals from the northern to southern borders of the region in areas located along the Volga river on the Volga upland and in the Oka–Don plain. Of these, one individual from Khvalynsky district turned out to be an Asian badger, one individual from Krasnoarmeysky district was a hybrid of the two named species, and three individuals, one from Tatishchevsky, the second from Volsky and the third from Khvalynsky districts showed introgression of Asian badger genes into the genotype of the European badger. Thus, we have managed to find out that at this stage of development of the phase of the climatic cycle in the Lower Volga region, characterized by warming winters, the Volga river, with its two reservoirs within the Saratov region, is not an absolute zoogeographical boundary, and badgers, whose species are characterized by winter sleep, can in certain conditions overcome, most likely on ice, both the river itself and the lake parts of the Volgograd and Saratov reservoirs. According to the revealed introgression in some individuals from different areas on the Volga upland of the right bank of the Saratov region, it can be assumed that such traveling across the Volga river took place earlier, possibly before its flow was regulated by dams.

Visualization of the dentogingival junction using micro-plastination technique.

Plastination has revolutionized the field of anatomy and research by providing biosecurity and enabling the long-term preservation of biological material, ranging from entire bodies to individual organs and even micron sections. The dentogingival junction (DGJ) consists of both epithelial and connective tissues that are closely related to the tooth's mineralized tissues. Cutting-grinding techniques are commonly used to visualize DGJ histology. These techniques exclude enamel from preparations and focus on visualizing hard or soft tissues. To improve the micro-anatomical and histological study of this region, we applied micro-plastination technique to obtain micro-thin slices below 150 μm thick from human and animal samples. The DGJ microanatomy was visualized by applying histological stains to the micro-plastinated slices, highlighting the technique's endogenous autofluorescence capacity identifying periodontal tissues, including dentin, enamel, cementoenamel junction, dentinal tubules, connective tissue, and collagen. Based on our results, we confirm that micro-plastination is a useful technique for visualizing anatomical regions that are difficult to access, such as the DGJ. Micro-plastination can be used as an alternative technique, providing a new approach for its application in anatomical and morphological research protocols.

Numerical calculation of heat transfer in cylindrical coordinates using finite-difference method in evaluating temperature of different points of radiopharmaceutical vials

Choosing the type of vial of radiopharmaceuticals, the materials of canned goods and food, as well as the thickness of their walls, plays an important role in the transportation of companies' products. Regularly, the optimal design of the type of food wall has a significant effect on the shelf life of the products inside it, which can be more resistant to heat. Especially, carrying vials of radiopharmaceuticals, which plays a vital role in medical centers and hospitals in hot cities around the world. Therefore, in this research, different points of a container containing biological material are analyzed numerically to estimate the heat transfer and the temperature distribution in it.

Bilateral transobturator hysterosuspension using titanium tape-shaped mesh implants in women with apical prolapse of the internal genitalia

BACKGROUND: Pelvic organ prolapse is a common pathology with several relapses of the disease after surgical treatment using exclusively self-tissues, which necessitates the development of new surgical techniques using durable and biological inert materials. AIM: To evaluate the effectiveness and safety of an original surgical technique for apical prolapse correction in patients of reproductive and pre- and postmenopausal age. MATERIAL AND METHODS: Twenty-nine patients were examined and operated on using a developed original technique with the use of narrow tape-shaped titanium mesh implants. RESULTS: Follow-up was conducted at 1, 6, 12, and 24 months postoperatively. Comparison of patient survey indicators in the pre- and postoperative periods showed an improvement in the patients’ quality of life and an increase in their social and sexual activity. During the first month, 15 (51.7%) patients reported intermittent pulling pains in the perineal and/or inguinal–femoral folds, and 4 (13.8%) reported frequent urination. Clinical examination revealed complete preservation of the surgical correction of prolapse in all patients. Gynecological and rectal examinations and transperineal and transvaginal echography did not show displacement of pelvic organs or titanium implants. Mesh-associated complications were not noted during the observation period. CONCLUSION: The developed original technique for surgical correction of second-degree apical prolapse with the use of narrow ribbon-shaped titanium mesh implants is effective and safe. This is evidenced by the normalization of the uterus position in the pelvis, absence of displacement of pelvic organs in the near and distant postoperative periods, and absence of mesh-associated complications during the observation time.

Engineered Tendon-Fibrocartilage-Bone Composite With Mechanical Stimulation for Augmentation of Rotator Cuff Repair: A Study Using an In Vivo Canine Model With a 6-Month Follow-up

Background: Rotator cuff repair augmentation using biological materials has become popular in clinical practice to reduce the high retear rates associated with traditional repair techniques. Tissue engineering approaches, such as engineered tendon-fibrocartilage-bone composite (TFBC), have shown promise in enhancing the biological healing of rotator cuff tears in animals. However, previous studies have provided limited long-term data on TFBC repair outcomes. The effect of mechanical stimulation on TFBC has not been explored extensively. Purpose: To evaluate functional outcomes after rotator cuff repair with engineered TFBC subjected to mechanical stimulation in a 6-month follow-up using a canine in vivo model. Study Design: Controlled laboratory study. Methods: A total of 40 canines with an acute infraspinatus (ISP) tendon transection model were randomly allocated to 4 groups (n =10): (1) unilateral ISP tendon undergoing suture repair only (control surgery); (2) augmentation with engineered TFBC alone (TFBC); (3) augmentation with engineered TFBC and bone marrow-derived stem cells (BMSCs) (TFBC+C); and (4) augmentation with engineered TFBC and BMSCs, as well as mechanical stimulation (TFBC+C+M). Outcome measures—including biomechanical evaluations such as failure strength, stiffness, failure mode, gross appearance, ISP tendon and muscle morphological assessment, and histological analysis—were performed 6 months after surgery. Results: As shown in the mechanical test, the TFBC+C+M group exhibited higher failure strength compared with other repair techniques. The most common failure mode was avulsion fracture in the TFBC+C+M group, but tendon-bone junction rupture was observed predominantly in different groups. Engineered TFBC with mechanical stimulation showed over 70% relative failure strength compared with normal ISP, and the other groups showed about 50% relative failure strength. Histological analysis revealed less fat infiltration and closer-to-normal muscle fiber structure in the mechanical stimulation group. Conclusion: This study provides evidence that mechanical stimulation of engineered TFBC promotes rotator cuff regeneration, thus supporting its potential for rotator cuff repair augmentation. Clinical Relevance: This study provides valuable evidence supporting the use of a novel tissue-engineered material (TFBC) in rotator cuff repair and paves the way for advancements in the field of rotator cuff regeneration.

Improvement of Mechanical Properties of 3D Bioprinted Structures through Cellular Overgrowth

The common use of hydrogel materials in 3D bioprinting techniques is dictated by the unique properties of hydrogel bioinks, among which some of the most important in terms of sustaining vital cell functions in vitro in 3D cultures are the ability to retain large amounts of liquid and the ability to modify rigidity and mechanical properties to reproduce the structure of the natural extracellular matrix. Due to their high biocompatibility, non-immunogenicity, and the possibility of optimizing rheological properties and bioactivity at the same time, one of the most commonly used hydrogel bioink compositions are polymer solutions based on sodium alginate and gelatin. In 3D bioprinting techniques, it is necessary for hydrogel printouts to feature an appropriate geometry to ensure proper metabolic activity of the cells contained inside the printouts. The desired solution is to obtain a thin-walled printout geometry, ensuring uniform nutrient availability and gas exchange during cultivation. Within this study’s framework, tubular bioprinted structures were developed based on sodium alginate and gelatin, containing cells of the immortalized fibroblast line NIH/3T3 in their structure. Directly after the 3D printing process, such structures are characterized by extremely low mechanical strength. The purpose of this study was to perform a comparative analysis of the viability and spreading ability of the biological material contained in the printouts during their incubation for a period of 8 weeks while monitoring the effect of cellular growth on changes in the mechanical properties of the tubular structures. The observations demonstrated that the cells contained in the 3D printouts reach the ability to grow and spread in the polymer matrix after 4 weeks of cultivation, leading to obtaining a homogeneous, interconnected cell network inside the hydrogel after 6 weeks of incubation. Analysis of the mechanical properties of the printouts indicates that with the increasing time of cultivation of the structures, the degree of their overgrowth by the biological material contained inside, and the progressive degradation of the polymer matrix process, the tensile strength of tubular 3D printouts varies.