Mechanical properties and osteointegration of the mesh structure of a lumbar fusion cage made by 3D printing.

The currently popular 3D printing makes it possible to produce spatial scaffolds, the main purpose of which is to obtain implants that have favourable mechanical properties to promote cell adhesion. This study aims to prove the influence of changes in selected geometrical parameters of scaffolds, used in intervertebral cages, on the mechanical properties obtained and thus on the osteointegration of the studied constructs with osteoblasts and fibroblasts. The stiffness values and maximum failure force of four modifications to geometric dimensions of the meshes were determined from the intendation test. Adhesion assays were conducted (including gentle pendulum motion) for Balb/3T3 fibroblasts and NHOst osteoblasts. The study revealed that an important geometrical parameter affecting the strength of the mesh is the height (h) of the connection point between arms of successive mesh cells. There was no significant effect of the mesh geometry on the abundance and survival of Balb/3T3 and NHOst cells. At the same time, fibroblasts were more likely to form colonies in the area where there is fusion of mesh cells, as opposed to osteoblasts that were more numerous at vertices of the mesh.

The Increased Mortality Rate with Lower Incidence of Traumatic Brain Injury during the COVID-19 Pandemic: A National Study.

BACKGROUND: the COVID-19 pandemic with the following lockdown strategies have affected virtually all aspects of everyday life. Health services all over the world faced the crisis on an unprecedented scale, hampering timely care delivery. The present study was designed to assess the impact of the COVID-19 outbreak on the incidence and treatment of traumatic brain injuries in Poland. METHODS: the data on hospital admissions with traumatic brain injuries as the primary diagnosis were extracted from the National Health Fund of Poland. For the purpose of this study, the search was limited to four relevant diagnosis-related groups. The overall in-house mortality was calculated. RESULTS: there were 115,200 hospitalizations due to traumatic brain injury identified in the database. Overall, in comparison with the average of six prior years, in 2020 the volume of patients with traumatic brain injury dropped by 24.68% while the in-house mortality rate was increased by 26.75%. CONCLUSIONS: the COVID-19 pandemic with the resulting lockdown caused a radical reduction in human mobility. It had a profound impact on the incidence of traumatic brain injury, which dropped significantly. At the same time, the mortality rate increased drastically.

Effect of overload on changes in mechanical and structural properties of the annulus fibrosus of the intervertebral disc.

The research focussed on analysing structural and mechanical properties in the intervertebral disc (IVD), caused by long-term cyclic loading. Spinal motion segments were divided into two groups: the control (C), and the group in which it was analysed the impact of posterior column in the load-bearing system of the spine-specimens with intact posterior column (IPC) and without posterior column (WPC). To evaluate the structural and mechanical changes, the specimens were tested with simulation of 100,000 compression-flexion load cycles after which it was performed macroscopic analysis. Mechanical properties of the annulus fibrosis (AF) from the anterior and posterior regions of the IVD were tested at the uniaxial tension test. The stiffness coefficient values were statistically 32% higher in the WPC group (110 N/mm) than in the IPC (79 N/mm). The dynamics of increase in this parameter does not correspond with the course of decrease in height loss. WPC segments revealed clear structural changes that mainly involve the posterior regions of the IVD (bulging and delamination with the effect of separation of collagen fibre bundles). Pathological changes also caused decreases in the value of stress in the AF. The greatest changes in the stress value about group C (7.43 ± 4.49 MPa) were observed in the front part of the fibrous ring, where this value was for IPC 4.49 ± 4.78 MPa and WPC 2.56 ± 1.01 MPa. The research indicates that the applied load model allows simulating damage that occurs in pathological IVD. And the posterior column's presence affects this change's dynamics, structural and mechanical properties of AF.

Multiscale structural characterization of the vertebral endplate in animal models.

Research in the field of spinal biomechanics, including analyses of the impact of implants on the stability of the spine, is conducted extensively in animal models. One of the basic problems in spinal implantation is the transfer and distribution of loads carried by the spine on the surfaces of the vertebral bodies. An important factor in proper cooperation of spinal implants with the vertebrae is the endplate (EP), which is why the EP in the animal model used for testing should be as similar as possible to the human EP. Therefore, this study involved multiscale structural and morphometric analyses of the animal models most commonly used in spinal biomechanics research, i.e. pig, ovine, and bovine tail. The tests were performed on 28 lumbar porcine, ovine, and bovine vertebrae. Both cranial and caudal EPs were analysed in three selected areas: anterior, middle, and posterior EPs. The conducted tests included a morphometric analysis of the trabecular bone (TB) layer of the EP as well as microscopic analysis at the mesoscale (total thickness) and microscale (thickness of the individual EP layers). The porcine EP had a characteristic increased circumferential thickness (~3 mm) with a significant narrowing in the central region (50%-60%). The convex cranial ovine EP had a constant thickness throughout the cross-section and the concave caudal EP showed ~35% narrowing in the central region. The thickest EPs were observed in the bovine tail model with negligibly small narrowing in the central region (~5%). The thickness of the cartilaginous layer in the porcine and bovine models reached up to 1 mm in the peripheral regions and decreased in the central part. The growth plate layer had a similar thickness in all the models. On the other hand, the narrowing of the total thickness of the EPs in the central region was mainly due to a decrease in the VEP thickness. In the ovine and bovine models, the central region of the EP was characterized by large isotropy and trabeculae of mixed or rod-like shape. By contrast, in the pig, this region had plate-like trabeculae of anisotropic nature. The porcine model was identified as best reflecting the shape and structure of the human EP and as the best surrogate model for the human EP model. This choice is particularly important in the context of biomechanical research.

Trabecular bone remodelling in the femur of C57BL/6J mice treated with diclofenac in combination with treadmill exercise.

PURPOSE: Analgesic treatment with diclofenac deteriorates bone structure and decreases biomechanical properties. This bone loss has been though to be reversed by training. The impact of exercise on bone treated with diclofenac (DF) has reminded elusive. In the present study, we assayed the combined impact of exercises and DF on mouse femur. METHODS: The femur samples we obtained from 30 days treated C57BL/6J female mice. The training group ran on a horizontal treadmill at 12 m/min by 30 min a day (5% grade/slope). The group of ten mice treated with DF received the drug subcutaneously every day (5 mg/kg of body weight/day). The combined group ran on the treadmill and obtained DF. After 30 days, we sacrificed mice and studied their femurs using microcomputed tomography (µCT), dynamic mechanical analysis (DMA) and nanoindentation. RESULTS: We observed that treadmill running and DF decreased trabecular bone volume and mineral density. Combined effect of training and DF was not additive. A significant interaction of both parameters suggested protective effect of training on bone loss provoked by DF. The femur cortical bone shell remained untouched by the training and treatment. The training and the DF treatment did not alter the storage modulus E' significantly. The unchanged storage modulus would be suggesting on the unaltered bone strength. CONCLUSIONS: We concluded that even relatively short time of training with concomitant DF treatment could be protective on trabecular bone. Although viscoelastic properties of the entire femur were not modulated, femur trabecular tissue was thinned by treatment with DF and protected by training.

Mechanical and histomorphometrical evaluation of false and floating ribs of young adults with idiopathic scoliosis.

PURPOSE: The aim of this paper was to assess the histomorphometrical and mechanical properties of ribs in patients with idiopathic scoliosis who underwent corrective surgery of scoliosis combined with thoracoplasty. METHODS: The analyzed material encompasses 20 females between the ages of 12 and 18, whose pre-operative Cobb angle was 56.85 degrees, on average. The participants were divided into two age groups, up to the age of 15 and above 15 years old, taking into account the anatomical location of the assessed rib fragments with a division into floating and false ribs. The analysis of mechanical parameters was carried out by means of the quasi-static 3-point bending test, and the histomorphometric evaluation of the examined rib fragments was carried out using high-resolution computed tomography. RESULTS: The existence of explicit relationships between selected radiological parameters describing scoliosis and mechanical and histomorphometric parameters of the ribs has not been confirmed. Statistically significant correlations between age and rib stiffness as well as between Young's modulus and stiffness depending on the anatomical location of the examined rib fragment were confirmed. CONCLUSIONS: Mechanical and histomorphometric properties of bone tissue in patients with scoliosis are not explicitly associated with the radiological parameters characterizing scoliosis.

Laser Texturing as a Way of Influencing the Micromechanical and Biological Properties of the Poly(L-Lactide) Surface.

Laser-based technologies are extensively used for polymer surface patterning and/or texturing. Different micro- and nanostructures can be obtained thanks to a wide range of laser types and beam parameters. Cell behavior on various types of materials is an extensively investigated phenomenon in biomedical applications. Polymer topography such as height, diameter, and spacing of the patterning will cause different cell responses, which can also vary depending on the utilized cell types. Structurization can highly improve the biological performance of the material without any need for chemical modification. The aim of the study was to evaluate the effect of CO2 laser irradiation of poly(L-lactide) (PLLA) thin films on the surface microhardness, roughness, wettability, and cytocompatibility. The conducted testing showed that CO2 laser texturing of PLLA provides the ability to adjust the structural and physical properties of the PLLA surface to the requirements of the cells despite significant changes in the mechanical properties of the laser-treated surface polymer.

The denticulate ligament - Tensile characterisation and finite element micro-scale model of the structure stabilising spinal cord.

BACKGROUND: Damage to the spinal cord is one of the most debilitating pathologies with considerable health, economic and social impact. Improved prevention, treatment and rehabilitation after spinal cord injury (SCI) requires the complex biomechanics of the spinal cord with all its structural elements and the injury mechanism to be understood. This comprehensive understanding will also allow development of models and tools enabling better diagnosis, surgical treatment with increased safety and efficacy and possible development of regenerative therapies. The denticulate ligaments play an important role in stabilising spinal cord within the spinal canal. They participate in spinal cord movements and play a role in determining the stress distribution during physiological but also traumatic loading. We present detailed tensile characterisation of the denticulate ligaments and a Finite Element micro-scale model of the ligament relating its structure with the distribution of stress under physiological loading. METHOD: Denticulate ligaments were dissected from cervical spinal levels from 6 porcine cervical specimens with fragments of the pia and dura mater and characterised in terms of their geometry and response to uniaxial tensile loading. The stress-strain characteristics were recorded until rupture of the ligament, ultimate parameters and Young's moduli were determined. The parametric micro-structural Finite Element model was constructed based on literature microscope and histological images of a denticulate ligament as a phenomenological representation of the complex microstructure of a soft tissue. The model was validated against the experimental data. RESULTS: Stress-strain characteristics obtained in tensile test were typical for a soft tissue behaviour. No statistically relevant differences in ultimate strength, strain and Young's moduli were observed between the ligaments harvested from different vertebral levels. Average ultimate tensile stress was 1.26 ±â€¯0.20 MPa at strain 0.51 ±â€¯0.00, rupturing force (1.01 ±â€¯0.21 N) was in agreement with results obtained previously. The Finite Element model accurately predicted the extension-load behaviour of the denticulate ligament in elastic regime. The micro-scale structural representation enabled capturing deformation modes representative of the experimentally observed behaviour. CONCLUSIONS: The presented stress-strain characteristics of the denticulate ligaments add valuable data to the understanding of the biomechanics of the spinal cord and enable development of more accurate models. The developed micro-scale model was capable of capturing biomechanical response of collagenous tissue under tensile loading, it can be applied for the prediction of other soft tissues behaviours. The denticulate ligament model should be included into future spinal cord models to fully represent the complex system's biomechanics and enable development of surgical aid tools to improve patient outcomes and future regenerative therapies.

Sensitivity analysis of the estimated muscle forces during gait with respect to the musculoskeletal model parameters and dynamic simulation techniques.

The purpose of the current study was to investigate the robustness of dynamic simulation results in the presence of uncertainties resulting from application of a scaled-generic musculoskeletal model instead of a subject-specific model as well as the effect of the choice of simulation method on the obtained muscle forces. The performed sensitivity analysis consisted of the following multibody parameter modifications: maximum isometric muscle forces, number of muscles, the hip joint centre location, segment masses as well as different dynamic simulation methods, namely static optimization with three different criteria and a computed muscle control algorithm (hybrid approach combining forward and inverse dynamics). Twenty-four different models and fifty-five resultant dynamic simulation data sets were analysed. The effects of model perturbation on the magnitude and profile of muscle forces were compared. It has been shown that estimated muscle forces are very sensitive to model parameters. The greatest impact was observed in the case of the force magnitude of the muscles generating high forces during gait (regardless of the modification introduced). However, the force profiles of those muscles were preserved. Relatively large differences in muscle forces were observed for different simulation techniques, which included both magnitude and profile of muscle forces. Personalization of model parameters would affect the resultant muscle forces and seems to be necessary to improve general accuracy of the estimated parameters. However, personalization alone will not ensure high accuracy due to the still unresolved muscle force sharing problem.

Finite element analysis of the influence of three-joint spinal complex on the change of the intervertebral disc bulge and height.

This study evaluated the changes of height and bulging occurring in individual layers of the annulus fibrosus of the intervertebral disc for 3 load scenarios (axial compression, flexion, and extension). The numerical model of a single motion segment of the thoracic spine was analysed for 2 different configurations, ie, for the model of a physiological segment and a segment with the posterior column removed. In the physiological segment, all annulus fibrosus layers decrease in height regardless of the applied load, bulging outside the intervertebral disc. Removal of the posterior column increases mobility and disrupts the load transfer system, with the lamellae bulging into the intervertebral disc.

Biomechanical analysis of the durability of a modified S1 vertebrae transpedicular screws insertion technique.

BACKGROUND: One of the most important elements of the transpedicular screw implantation technique, which enables a strong screw-bone interface, is the precise choice of the site of screw insertion and the screw's trajectory. Due to the complex biomechanics of the lumbosacral interface and different shape of the sacrum, fixation of this segment remains a challenge for surgeons. Because of this, Kubaszewski et al. proposed a modified technique in which the entry point for screw insertion in the S1 vertebra is changed. METHODS: Six human cadaver specimens of the S1 vertebrae were examined. Two transpedicular screws were inserted into the body of each examined vertebra using two implantation methods with different screw entry points and trajectories. The screws were subjected to cyclic preloading, followed by the pull-out test. The ultimate pull-out force, displacement, stiffness, and failure energy were measured. FINDINGS: The average pull-out force obtained for the standard method of implantation was 498 N (SD 201), whereas for the modified technique, it was 1308 N (SD 581). Displacement of the inserted screws in the new method was 36% higher than in the case of the standard method. This method is also characterized by the greater stiffness of the obtained interface and greater failure energy than the normally used technique. INTERPRETATION: The obtained results demonstrate that the use of the new technique of implantation significantly increases the strength of the obtained screw-bone interface. It should also increase the success rate of the performed fixations and increase the safety of such fixations in clinical practice.

The impact of development of atherosclerosis on delamination resistance of the thoracic aortic wall.

The aim of this work is to determine the impact of development of atherosclerosis on dissection of the human thoracic aorta on the basis of an analysis of the mechanical properties of the interfaces between its layers. The research material consisted of 17 pathologically unchanged aortae and 74 blood vessels with atherosclerotic lesions, which were classified according to the histological classification by Stary. The subject of the analysis were the interfaces between the adventitia and the media-intima complex (A-MIC) and between the intima and the media-adventitia complex (I-MAC). The mechanical properties of the above interfaces were determined by the peeling test in the longitudinal and circumferential directions. The results indicate that development of atherosclerosis reduces vessel wall resistance to delamination. The greatest risk of dissection occurs at stage IV of the disease. In this case, energy values are lower by about 28% for the I-MAC interface and by 39% for the A-MIC interface compared with normal tissues. Lower values of mean force and energy were obtained for the I-MAC interface, indicating that this interface is more susceptible to delamination. The mechanical properties of the A-MIC interfaces are directional.

Modulating effect of selected pharmaceuticals on bone in female rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

This paper discusses the problems connected with the influence of TCDD on the mechanical properties and structure of the bone tissue in female rats treated with the dioxin. Moreover an analysis of the protective role of tocopherol, acetylsalicylic acid, dexamethazone and levamisol was performed. Rat tibiae were assessed by mechanical testing, and histological and trace element analysis. It was proved that TCDD has negative effect on bone mechanical properties, histological microstructure and trace element content. The results indicate that usage of both steroid and non-steroid anti-inflammatory medicaments, along with tocopherol and levamisol, modulating their activity, can reduce the negative effect of dioxin activity on the bone tissue of female rats intoxicated with TCDD.

The content of collagen type II in human arteries is correlated with the stage of atherosclerosis and calcification foci.

OBJECTIVE: The signature processes during atherosclerosis development are arterial calcification and accumulation in the arterial walls of proteins that are specific to bone and cartilage, e.g., collagen type II. The purpose of this study was to characterize localization of collagen type II and quantify its content in human arteries. RESULTS: The study was conducted on sections of thoracic and abdominal aortas (n=97) subjected to histological evaluation and classified into six grades according to the Stary scale of the atherosclerosis severity. Three types of samples were distinguished from the group of arteries: (1) without macroscopically visible calcifications, (2) with macroscopically visible calcifications dispersed within the arterial wall, and (3) calcium deposits isolated from the walls tested with respect to the segment of the artery from which they had originated. The results demonstrate that both cholesterol and collagen type II content are significantly higher in samples with calcification, whereas collagen type II is localized mainly in the tissue around the calcium deposit. A positive correlation has been shown between the levels of collagen type II and cholesterol (r=0.57, P<.05). A similar trend was observed with respect to the grade of atherosclerosis (r=0.43, P<.05). CONCLUSIONS: The amount of collagen type II is higher in the tissue around the calcium deposit. The correlation was observed between the quantityof collagen type II, the grade of atherosclerosis, and cholesterol.

Cytokine induction of sol-gel-derived TiO2 and SiO2 coatings on metallic substrates after implantation to rat femur.

Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant-tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS) and titanium alloy (Ti6Al4V) biomaterials coated with titanium dioxide (TiO2) and silica (SiO2) coatings prepared by sol-gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone-implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software) of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO2 groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol-gel TiO2 or SiO2 coatings reduced significantly the production of proinflammatory cytokines by local tissues, irrespective of the material used as a substrate, that is, either Ti6Al4V or SS. This suggests lower inflammatory response, which directly points out improvement of materials' biocompatibility.

Feasibility and accuracy of new insertion technique of S1 transpedicular screw. Computed tomography-based morphometric analysis.

OBJECTIVE: To assess feasibility and accuracy of a new insertion technique of S1 transpedicular screw. SUMMARY OF BACKGROUND DATA: Transpedicular stabilization in the first sacral vertebra (S1) is a technically demanding surgical procedure with inherent risk of loosening of the implant. A modification of the technique was recently proposed, along with the analytical verification which was performed based on the available literature. In the study, we performed radiological assessment of screws inserted into the S1 using the classical and modified techniques. METHODS: The analysis was performed in two parts. The first part was performed on eight cadaver specimens after implantation of the screws. In the second part, we used computed tomography images of patients with degenerative disk disease with a superimposed representation of screws. The thickness of the posterior cortex adherent to the screws, screw trajectory and their position with regard to the spinal canal was measured. The area of posterior cortex in contact with the screws was also calculated. RESULTS: The contact length and area was found to be two times greater for screws introduced with the modified technique. The convergence angle was comparable between the techniques, despite the shift of entry point. There was no canal breach, although with the modified technique the screws passed closer to the spinal canal. CONCLUSIONS: The modified technique is considered safe. In this technique, the screws pass through a thicker portion of the posterior cortex compared to the classical technique that aims at improving the stability of the fixation.

Analysis of the impact of the course of hydration on the mechanical properties of the annulus fibrosus of the intervertebral disc.

PURPOSE: The aim of this study was to determine the impact of free hydration on the mechanical parameters of the annulus fibrosus (AF) of the intervertebral disc (IVD), determined in a standard manner. Attention was also given to the hydration occurring in real time and geometric changes resulting from swelling of the AF. METHODS: Uniaxial tensile tests of multilayer samples of the AF with bone attachment were performed for two groups: samples subjected to 30 min of hydration prior to the mechanical test, and control samples, which were not subjected to additional hydration. RESULTS: As a result of hydration, the values of both the failure stress (σ UTS) and the tensile modulus (E) were lower than in the control group. A decrease in these values was observed for the AF from both the anterior and posterior parts of the IVD. CONCLUSIONS: The tests showed a significant dependence of the determined mechanical parameters on the cross-sectional area. The larger the cross-sectional area, the lower the obtained value of stress. By contrast, the value of the stiffness coefficient is independent of the cross-sectional area. The differences in mechanical parameters are related mainly to water absorption into structures of the AF during hydration. This is confirmed by microscopic analysis of geometric dimensions of the AF during hydration conducted in real time. The greatest changes occurred in the radial direction, where the thickness increased by 2.05 mm, while in the axial direction the main change concerned an increase in height by 0.69 mm. There were negligible changes in the circumferential direction.

Qualitative and quantitative assessment of collagen and elastin in annulus fibrosus of the physiologic and scoliotic intervertebral discs.

The biophysical properties of the annulus fibrosus of the intervertebral disc are determined by collagen and elastin fibres. The progression of scoliosis is accompanied by a number of pathological changes concerning these structural proteins. This is a major cause of dysfunction of the intervertebral disc. The object of the study were annulus fibrosus samples excised from intervertebral discs of healthy subjects and patients treated surgically for scoliosis in the thoracolumbar or lumbar spine. The research material was subjected to structural analysis by light microscopy and quantitative analysis of the content of collagen types I, II, III and IV as well as elastin by immunoenzymatic test (ELISA). A statistical analysis was conducted to assess the impact of the sampling site (Mann-Whitney test, α=0.05) and scoliosis (Wilcoxon matched pairs test, α=0.05) on the obtained results. The microscopic studies conducted on scoliotic annulus fibrosus showed a significant architectural distortion of collagen and elastin fibres. Quantitative biochemical assays demonstrated region-dependent distribution of only collagen types I and II in the case of healthy intervertebral discs whereas in the case of scoliotic discs region-dependent distribution concerned all examined proteins of the extracellular matrix. Comparison of scoliotic and healthy annulus fibrosus revealed a significant decrease in the content of collagen type I and elastin as well as a slight increase in the proportion of collagen types III and IV. The content of collagen type II did not differ significantly between both groups. The observed anomalies are a manifestation of degenerative changes affecting annulus fibrosus of the intervertebral disc in patients suffering from scoliosis.

Kinematic Analysis of a Six-Degrees-of-Freedom Model Based on ISB Recommendation: A Repeatability Analysis and Comparison with Conventional Gait Model.

Objective. The purpose of the present work was to assess the validity of a six-degrees-of-freedom gait analysis model based on the ISB recommendation on definitions of joint coordinate systems (ISB 6DOF) through a quantitative comparison with the Helen Hays model (HH) and repeatability assessment. Methods. Four healthy subjects were analysed with both marker sets: an HH marker set and four marker clusters in ISB 6DOF. A navigated pointer was used to indicate the anatomical landmark position in the cluster reference system according to the ISB recommendation. Three gait cycles were selected from the data collected simultaneously for the two marker sets. Results. Two protocols showed good intertrial repeatability, which apart from pelvic rotation did not exceed 2°. The greatest differences between protocols were observed in the transverse plane as well as for knee angles. Knee internal/external rotation revealed the lowest subject-to-subject and interprotocol repeatability and inconsistent patterns for both protocols. Knee range of movement in transverse plane was overestimated for the HH set (the mean is 34°), which could indicate the cross-talk effect. Conclusions. The ISB 6DOF anatomically based protocol enabled full 3D kinematic description of joints according to the current standard with clinically acceptable intertrial repeatability and minimal equipment requirements.

In vitro hemocompatibility studies of (poly(L-lactide) and poly(L-lactide-co-glycolide) as materials for bioresorbable stents manufacture.

Vascular stents are one of the most popular modern methods of dealing with advanced coronary artery disease. At the same time stents are foreign objects to the body, they can stimulate proliferation of vascular endothelium and finally lead to restenosis. Biomaterials designed for temporary and permanent contact with an organism should be biologically inert especially in the case of contact with liquid tissue such as blood. The study aims to assess the impact of resorbable polymers: poly(L-lactide) (PLLA) and poly(L-lactide-co-glycolide) (PLGA), intended for the construction of bioresorbable stents, on activation of coagulation, haemolysis, and morphology of blood cells. The test results showed that in terms of haemolytic activity the samples selected from PLLA and PLGA, shaped by compression pressure followed by laser cutting, do not cause changes in the structural elements of blood and meet the biocompatibility requirements for materials intended for use in the circulatory system.