The Fabrication of Bioresorbable Implants for Bone Defects Replacement Using Computer Tomogram and 3D Printing

The present work demonstrates the possibility of production of personalized implants from bioresorbable polymers designed for replacement of bone defects. The stages of creating a personalized implant are described, which include the obtaining of 3D model from a computer tomogram, development of the model with respect to shape of bone fitment bore using Autodesk Meshmixer software, and 3D printing process from bioresorbable polymers. The results of bioresorbable polymer scaffolds implantation in pre-clinical tests on laboratory animals are shown. The biological properties of new bioresorbable polymers based on poly(lactic acid) were studied during their subcutaneous, intramuscular, bone and intraosseous implantation in laboratory animals. In all cases, there was a lack of a fibrous capsule formation around the bioresorbable polymer over time. Also, during the performed study, conclusions were made on osteogenesis intensity depending on the initial state of bone tissue

The Fabrication of Bioresorbable Implants for Bone Defects Replacement Using Computer Tomogram and 3D Printing

The present work demonstrates the possibility of production of personalized implants from bioresorbable polymers designed for replacement of bone defects. The stages of creating a personalized implant are described, which include the obtaining of 3D model from a computer tomogram, development of the model with respect to shape of bone fitment bore using Autodesk Meshmixer software, and 3D printing process from bioresorbable polymers. The results of bioresorbable polymer scaffolds implantation in pre-clinical tests on laboratory animals are shown. The biological properties of new bioresorbable polymers based on poly(lactic acid) were studied during their subcutaneous, intramuscular, bone and intraosseous implantation in laboratory animals. In all cases, there was a lack of a fibrous capsule formation around the bioresorbable polymer over time. Also, during the performed study, conclusions were made on osteogenesis intensity depending on the initial state of bone tissue

Structure and properties of biodegradable PLLA/ZnO composite membrane produced via electrospinning

These days, composite materials based on polymers and inorganic nanoparticles (NPs) are widely used in optoelectronics and biomedicine. In this work, composite membranes of polylactic acid and ZnO NPs containing 5–40 wt.% of the latter NPs were produced by means of electrospinning. For the first time, polymer material loaded with up to 40 wt.% of ZnO NPs (produced via laser ablation in air and having non-modified surface) was used to prepare fiber-based composite membranes. The morphology, phase composition, mechanical, spectral and antibacterial properties of the membranes were tested by a set of analytical techniques including SEM, XRD, FTIR, UV-vis, and photoluminescence spectroscopy. Antibacterial activity of the materials was evaluated following standard procedures (ISO 20743:2013) and using S. aureus and E. coli bacteria. It is shown that incorporation of 5–10 wt.% of NPs led to improved mechanical properties of the composite membranes, while further increase of ZnO content up to 20 wt.% and above resulted in their noticeable deterioration. At the same time, the antibacterial properties of ZnO-rich membranes were more pronounced, which is explained by a larger number of surface-exposed ZnO NPs, in addition to those embedded into the bulk of fiber material

Calcium phosphate coatings produced by radiofrequency magnetron sputtering method

Calcium phosphate coatings on titanium implants surface, produced by radio frequency (RF) magnetron sputtering method with hydroxyapatite solid target were investigated. It was found that produced coatings are calcium deficient compared to stoichiometric hydroxyapatite. The surface of the coatings is highly rough at the nanoscale and highly elastic. In vivo experiments on rats revealed that titanium implants with the calcium phosphate coatings do not cause negative tissue reaction after 6 months incubation period

Composite implants coated with biodegradable polymers prevent stimulating tumor progression

In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety

Composite implants coated with biodegradable polymers prevent stimulating tumor progression

In this experiment we studied oncologic safety of model implants created using the solution blow spinning method with the use of the PURASORB PL-38 polylactic acid polymer and organic mineral filler which was obtained via laser ablation of a solid target made of dibasic calcium phosphate dihydrate. For this purpose the implant was introduced into the area of Wistar rats’ iliums, and on day 17 after the surgery the Walker sarcoma was transplanted into the area of the implant. We evaluated the implant’s influence on the primary tumor growth, hematogenous and lymphogenous metastasis of the Walker sarcoma. In comparison with sham operated animals the implant group demonstrated significant inhibition of hematogenous metastasis on day 34 after the surgery. The metastasis inhibition index (MII) equaled 94% and the metastases growth inhibition index (MGII) equaled 83%. The metastasis frequency of the Walker sarcoma in para aortic lymph nodes in the implant group was not statistically different from the control frequency; there was also no influence of the implant on the primary tumor growth noted. In case of the Walker sarcoma transplantation into the calf and the palmar pad of the ipsilateral limb to the one with the implant in the ilium, we could not note any attraction of tumor cells to the implant area, i.e. stimulation of the Walker sarcoma relapse by the implant. Thus, the research concluded that the studied implant meets the requirements of oncologic safety

Antibacterial ferroelectric hybrid membranes fabricated via electrospinning for wound healing

n the present study, wound healing ferroelectric membranes doped with zinc oxide nanoparticles were fabricated from vinylidene fluoride-tetrafluoroethylene copolymer and polyvinylpyrrolidone using the electrospinning technique. Five different ratios of vinylidene fluoride-tetrafluoroethylene to polyvinylpyrrolidone were used to control the properties of the membranes at a constant zinc oxide nanoparticle content. It was found that an increase of polyvinylpyrrolidone content leads to a decrease of the spinning solution conductivity and viscosity, causing a decrease of the average fiber diameter and reducing their strength and elongation. By means of X-ray diffraction and infrared spectroscopy, it was revealed that increased polyvinylpyrrolidone content leads to difficulty in crystallization of the vinylidene fluoride-tetrafluoroethylene copolymer in the ferroelectric β-phase in membranes. Changing the ratio of vinylidene fluoride-tetrafluoroethylene copolymer and polyvinylpyrrolidone with a constant content of zinc oxide nanoparticles is an effective approach to control the antibacterial properties of membranes towards Staphylococcus aureus. After carrying out in vivo experiments, we found that ferroelectric hybrid membranes, containing from five to ten mass percent of PVP, have the greatest wound-healing effect for the healing of purulent wound

Properties of calcium-phosphate coatings formed by pulsed laser deposition

The paper is dedicated to the research of calcium-phosphate coatings formed on the surface of the polymer layers (copolymer tetrafluoroethylene with vinylidene fluoride) by pulsed laser deposition. The calcium-phosphate coatings were formed using two different by composition targets. The morphology of the obtained coatings was analyzed by Scanning Electron Microscopy, the elemental composition was analyzed by Energy Dispersive Analysis, and the chemical composition was analyzed by Fourier Transform Infrared Spectroscopy

Electrospun VDF-TeFE Scaffolds Modified by Copper and Titanium in Magnetron Plasma and Their Antibacterial Activity against MRSA

Copolymer solution of vinylidene fluoride with tetrafluoroethylene (VDF-TeFE) was used for electrospinning of fluoropolymer scaffolds. Magnetron co-sputtering of titanium and copper targets in the argon atmosphere was used for VDF-TeFE scaffolds modification. Scanning electron microscopy (SEM) showed that scaffolds have a nonwoven structure with mean fiber diameter 0.77 ± 0.40 μm, mean porosity 58 ± 7%. The wetting angle of the original (unmodified) hydrophobic fluoropolymer scaffold after modification by titanium begins to possess hydrophilic properties. VDF-TeFE scaffold modification by titanium/copper leads to the appearance of strong antibacterial properties. The obtained fluoropolymer samples can be successfully used in tissue engineering