Optimizing Filament-Based TCP Scaffold Design for Osteoconduction and Bone Augmentation: Insights from In Vivo Rabbit Models.

Additive manufacturing has emerged as a transformative tool in biomedical engineering, offering precise control over scaffold design for bone tissue engineering and regenerative medicine. While much attention has been focused on optimizing pore-based scaffold architectures, filament-based microarchitectures remain relatively understudied, despite the fact that the majority of 3D-printers generate filament-based structures. Here, we investigated the influence of filament characteristics on bone regeneration outcomes using a lithography-based additive manufacturing approach.

TPMS Microarchitectures for Vertical Bone Augmentation and Osteoconduction: An In Vivo Study.

Triply periodic minimal surface microarchitectures (TPMS) were developed by mathematicians and evolved in all kingdoms of living organisms. Renowned for their lightweight yet robust attributes, TPMS structures find application in diverse fields, such as the construction of satellites, aircrafts, and electric vehicles. Moreover, these microarchitectures, despite their intricate geometric patterns, demonstrate potential for application as bone substitutes, despite the inherent gothic style of natural bone microarchitecture.

Functionalization of Ceramic Scaffolds with Exosomes from Bone Marrow Mesenchymal Stromal Cells for Bone Tissue Engineering.

The functionalization of bone substitutes with exosomes appears to be a promising technique to enhance bone tissue formation. This study investigates the potential of exosomes derived from bone marrow mesenchymal stromal cells (BMSCs) to improve bone healing and bone augmentation when incorporated into wide open-porous 3D-printed ceramic Gyroid scaffolds. We demonstrated the multipotent characteristics of BMSCs and characterized the extracted exosomes using nanoparticle tracking analysis and proteomic profiling.

Three-Dimensional Printed Hydroxyapatite Bone Substitutes Designed by a Novel Periodic Minimal Surface Algorithm Are Highly Osteoconductive.

Autologous bone remains the gold standard bone substitute in clinical practice. Therefore, the microarchitecture of newly developed synthetic bone substitutes, which reflects the spatial distribution of materials in the scaffold, aims to recapitulate the natural bone microarchitecture. However, the natural bone microarchitecture is optimized to obtain a mechanically stable, lightweight structure adapted to the biomechanical loading situation.

Triply Periodic Minimal Surface-Based Scaffolds for Bone Tissue Engineering: A Mechanical, and Study.

Triply periodic minimal surfaces (TPMSs) are found to be promising microarchitectures for bone substitutes owing to their low weight and superior mechanical characteristics. However, existing studies on their application are incomplete because they focus solely on biomechanical or aspects. Hardly any studies where different TPMS microarchitectures are compared have been reported.

Influence of Scaffold Microarchitecture on Angiogenesis and Regulation of Cell Differentiation during the Early Phase of Bone Healing: A Transcriptomics and Histological Analysis.

The early phase of bone healing is a complex and poorly understood process. With additive manufacturing, we can generate a specific and customizable library of bone substitutes to explore this phase. In this study, we produced tricalcium phosphate-based scaffolds with microarchitectures composed of filaments of 0.

Influence of chitin nanofibrils ultrasonic treatment on structure and properties of chitosan-based composite materials.

The influence of ultrasonic treatment parameters of chitin nanofibrils aqueous suspension on structure, strength and deformation properties of chitosan-based composite films and fibers was investigated. Model calculations of ultrasound-induced cavitation parameters in the aqueous suspension of the chitin nanofibrils showed that an increase in the field power up to 630 W led to destruction of the cavity, to an increase in the temperature in the vicinity of cavitation area (up to 507 °C) and, as a consequence, to destruction of chitin glycoside ring (which is confirmed by the IR data). The results of light scattering, IR spectroscopy, and electron microscopy investigations indicated that the optimal duration of ultrasonic treatment of the chitin nanofibrils aqueous solution was 4-10 min (depending on oriented state of the scaffold).

Influence of the Introduced Chitin Nanofibrils on Biomedical Properties of Chitosan-Based Materials.

Hemorrhage occurring during and after surgery still remains one of the biggest problems in medicine. Although a large number of hemostatic products have been created, there is no universal preparation; thus, the development of new materials is an urgent task. The aim of this research is to increase hemostatic properties of chitosan by introducing chitin nanofibrils (ChNF).

[Functional reserves of myocardial perfusion in patients with chronic ischemic heart disease with varying degrees of damage of the coronary arteries].

A comparative study of data provided by coronaro-angiography and myocardial perfusion scintigraphy (resting and exercise tests), and clinical/electrocardiographic results of the exercise test in 102 chronic coronary patients demonstrated that non-invasive myocardial perfusion 201Tl scintigraphy combined with threshold bicycle-ergometric exercise adds considerably to the clinico-electrocardiographic assessment of the exercise test and thus helps to detect myocardial blood supply (perfusion) disorders in some of coronary patients with doubtful or negative test results. Reduced functional reserves of myocardial blood supply, as reflected in deficient perfusion at the peak of threshold exercise, are seen in all coronary patients with angiographically intact coronary arteries and in most patients with both the so-called "functionally-insignificant" and marked coronary arterial stenosis (94.7 and 88.

[Infusion of prostaglandin E1 in resting angina resistant to conventional therapy].

Effect of 48-72 hour infusion of prostaglandin E1 (PGE1) was studied in 17 patients with angina refractory to conventional medical treatment (combination of propranolol, 160 mg/day nifedipin, 30 mg/day and nitrates) by the double blind test. PGE1 was infused to 11, placebo to 6 patients. There was no difference between PGE1 and placebo groups in the number of ischemic episodes and duration of myocardial ischemia as evidenced by Holter ECG monitoring.

[Newly developed stenocardia: electrocardiographic and angiographic comparisons and the possibility of conducting intraluminal dilatation of coronary arteries].

Fifty coronary patients were examined within the first 3 months after the onset of anginal attacks. All patients were subjected to coronaroangiographic investigation, bicycle ergometry, and 45 patients, to ECG-monitoring. Resting ECG patterns were assessed.

[Spasm of organically altered coronary arteries].

The paper is concerned with 11 patients with an angiographically recorded spasm at the site of the coronary artery stenosis. In the 2 patients, the spasm was spontaneous, whereas in the 9, it was provoked by ergometrine. None of the patients had a typical clinical picture of Prinzmetal's angina pectoris, but all the cases were characterized by exacerbation of coronary heart disease, which was manifested by repetition and increase of the intensity of attacks of angina pectoris at rest.

[Unstable angina pectoris: results of repeated ergometrine tests].

Ergometrine (ergonovine) tests were performed in patients with unstable angina on the 1st day of hospitalization, on 2nd--3rd days during which patients received only nitroglycerin sublingually for acute pain relief (33 observations), and after "stabilization" of their condition by calcium antagonists or/and beta-blockers (34 observations). Reactions to ergometrine were classified as spastic when pain was accompanied by ST segment elevations of T wave changes and as nonspecific when intravenous ergometrine resulted in ST segment depression and/or anginal attack. Spastic reactions to ergometrine observed in the acute period as a rule disappeared with "stabilization" of patients condition.

[Unstable stenocardia: the reaction to ergometrine administration].

Ergometrine test was undertaken on the 1--3d day after hospitalization in 49 patients with unstable angina pectoris. Pain or ECG changes were recorded in 90% of patients. Reactions with the rise of the ST segment and changes of the T wave on ECG were interpreted as "spastic" and were seen in 43% of cases.