The major problem in bone tissue engineering is the development of scaffolds which can simultaneously meet the requirements of porous structure, as well as have the ability to guide the regeneration of damaged tissue by biological fixation. Composites containing biodegradable matrix and bioactive filler are the new hope in this research field. Herein we employed a simple and facile solvent casting particulate-leaching method for producing polylactide acid/hydroxyapatite (PLA/HA) composites at room temperature. FT-IR analysis confirmed the existence of necessary functional groups associated with the PLA/HA composite, whereas energy-dispersive X-ray (EDX) spectra indicated the uniform distribution of hydroxyapatite particles in the polymer matrix. The beehive-like surface morphology of the composites revealed the presence of macropores, ranged from 300 to 400 μm, whereas the thickness of the pores was noticed to be 1–2 μm. The total porosity of the scaffolds, calculated by hydrostatic weighing, was found to be 79%. The water contact angle of pure PLA was decreased from 83.6 ± 1.91° to 62.4 ± 4.17° due to the addition of hydroxyapatite in the polymer matrix. Thus, the wettability of the polymeric biomaterial could be increased by preparing their composites with hydroxyapatite. The adhesion of multipotent mesenchymal stromal cells over the surface of PLA/HA scaffolds was 3.2 times (p = 0.03) higher than the pure PLA sample. Subcutaneous implantation in mice demonstrated a good tolerance of all tested porous scaffolds and widespread ingrowth of tissue into the implant pores. HA-containing scaffolds showed a less pronounced inflammatory response after two weeks of implantation compared to pure PLA. These observations suggest that PLA/HA composites have enormous potential for hard tissue engineering and restoring maxillofacial defects.

The acceleration in advancements of smart materials and non-contact controlled devices in the field of 4D printing is facilitated by the use of magnetically responsive shape memory polymer (SMP) composites. This study is dedicated to the development of promising shape memory materials based on polylactic acid (PLA) and cobalt ferrite (CoFe₂O₄) nanoparticles. The activation of the shape memory effect (SME) in magnetic nanoparticle composites was achieved by applying a high-frequency alternating magnetic field (HFAMF). The PLA/CoFe₂O₄ composites exhibited a remarkable shape recovery ratio (>84%) and underwent rapid heating when exposed to HFAMF. The interaction of these composites with mouse adipose-derived mesenchymal stem cells demonstrated adequate cytocompatibility. The rapid magnetosensitive behavior and high shape recovery characteristics of PLA/CoFe₂O₄ composites make them promising candidates for biomedical applications.

The present work aimed to study the synergistic response of bioresorbable polylactide/bioactive wollastonite scaffolds towards mechanical stability, mesenchymal stromal cell colonization, and antibacterial activity in the physiological environment. Wollastonite was synthesized at 800 °C within 2 h by sol-gel combustion method. The surface area was found to be 1.51 m²/g, and Transmission Electron Microscopy (TEM) micrographs indicated the presence of porous structures. Fused deposition modeling was used to prepare 3D-printed polylactide/wollastonite and polylactide/hydroxyapatite scaffolds. Scanning Electron Microscopy (SEM) micrographs confirmed the interconnected porous structure and complex geometry of the scaffolds. The addition of wollastonite decreased the contact angle of the scaffolds. The mechanical testing of scaffolds examined by computational simulation, as well as machine testing, revealed their non-load-bearing capacity. The chemical constituent of the scaffolds was found to influence the attachment response of different cells on their surface. The incorporation of wollastonite effectively reduced live bacterial attachment, whereas the colonization of mesenchymal cells was improved. This observation confirms polylactide/wollastonite scaffold possesses both bactericidal as well as cytocompatible properties. Thus, the risk of peri-implant bacterial film formation can be prevented, and the biological fixation of the scaffold at the defect site can be enhanced by utilizing these composites.

Background. Patients with malignant bone and joint tumors often require reconstructive surgery for osteosynthesis or arthrodesis. The design of the implant can be realized by 3D printing using biodegradable materials with shape memory effect, which will facilitate operative access and reduce the risk of reoperation.Aim. The study aimed to evaluate the mechanical properties, biocompatibility and biological activity of polylactide (PLA) with hydroxyapatite (HA) and silicon dioxide (SiO2) produced by extrusion and 3D printing to identify prospects for the development of implants based on them for osteoreconstructive surgeries.Materials and methods. Materials based on PLA with the addition of 10, 15 and 20 % HA and SiO2 were obtained by extrusion. These materials were 3D-printed to produce samples that underwent a compression test. Their extracts obtained after incubation of the samples in fetal calf serum for 30 days were examined. Biocompatibility was assessed by the level of hemolysis and cytotoxicity of the extracts, as well as stimulation of oxidative stress. The effects of the extracts on cell adhesion and intensity of multipotent mesenchymal stromal cells colonization on the surface of both intact and biodegraded samples were studied separately.Results. The addition of HA and SiO2 to PLA did not significantly increase hemolysis and cytotoxicity compared to pure PLA. However, incubation with extracts of samples containing 20 % stimulated an increase in oxidative stress in leukocytes, and inhibited cell adhesion. Samples with 10 and 15 % HA maximally stimulated cell colonization on the sample surface.Conclusion. Materials based on PLA with 10 and 15 % HA combine high strength, biocompatibility, biodegradability and effective osteoconductivity, which makes them promising candidates for implants for osteoreconstruction and arthrodesis.