poly lactic acid
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Author(s):  
Sriharsha Srinivas Sundarram ◽  
Nwachukwu Ibekwe ◽  
Stephanie Prado ◽  
Clarissa Rotonto ◽  
Sean Feeney

ACS Omega ◽  
2022 ◽  
Author(s):  
Alejandro Prada ◽  
Rafael I. González ◽  
María B. Camarada ◽  
Sebastián Allende ◽  
Alejandra Torres ◽  
...  

Author(s):  
Zhenyu Wang ◽  
Chi Yu ◽  
Shuhua Chen ◽  
Shiping Zhan

To meet the challenge of regenerating bone lost to disease or trauma, biodegradable scaffolds are being investigated as a way to regenerate bone without the need for an auto- or allograft. Herein, we prepared poly (lactic acid) (PLA)/chitosan(CS)/nano-hydroxyapatite biomaterials through solution polymerization and solvent volatilization. Cefadroxil was used as a model drug for loading on biomaterials using supercritical carbon dioxide. In addition, we investigated the in vitro drug release effect, and the in vitro release results showed that the drug could release more than 73% of the drug load within 48[Formula: see text]h. This excellent drug release property could allow continuous drug use at the wound site, further broadening its application in the medical field. A three-dimensional finite element (FE) model of bone screws was established, and the mechanical properties of the screws were numerically calculated. The stress and deformation of the bone screws under different external conditions were simulated. The bending simulation showed that the screw can withstand the maximum deformation of 0.418[Formula: see text]mm and equivalent stress of 566.94[Formula: see text]MPa at a force of 700 N. The maximum equivalent stress of the screw reached 321.84[Formula: see text]MPa, and the corresponding torque was 779.68 N[Formula: see text]mm when the torsion angle was gradually increased to 30[Formula: see text]. The fabricated material has excellent mechanical properties and can be used for bone repair. This study provides a new direction for preparing drug-loaded polymer biomaterials and developing new materials for bone repair.


2022 ◽  
pp. 088532822110649
Author(s):  
Juliana C Rosa ◽  
Jean J Bonvent ◽  
Arnaldo R Santos

The rotary jet spinning technique permits the production of biomaterials that can be used as devices that come into contact with biological systems (including biological fluids) for diagnostic or surgical applications. These materials are composed of synthetic or natural compounds and allow the incorporation of drugs for therapeutic purposes. Two solutions containing 50% poly(lactic acid) (PLA) and 50% poly(ε-caprolactone) (PCL) diluted in three different solvents were prepared for rotary jet spinning (RJS) process. Vancomycin, an antibiotic indicated for the treatment of severe staphylococcal infections in patients with penicillin allergy, was added in the polymer solutions, to obtain drug-loaded fibrous mats. Morphological surface characterization by scanning electron microscopy revealed heterogeneous pores in the microfibers. Vancomycin loading interfered with the morphology of all samples in terms of fiber size, leading to smaller diameter fibers. Attenuated total reflectance/Fourier transform infrared spectroscopy was used for identification of the samples. The vibrational characteristics of PCL/PLA and vancomycin were consistent with expectations. Vero cell culture assays by the extract dilution and direct contact methods revealed the absence of cytotoxicity, except for the sample prepared with 50% of PCL and of a 9/2 (V/V) vancomycin content, with the growth of confluent and evenly spread cells on the fibrous mats surface. Microbiological analysis, performed on Staphylococcus aureus by the halo inhibition test and by the broth dilution method, showed that the antibacterial activity of vancomycin was maintained by the loading process in the polymer fibers. The results showed that rotary jet spinning produces satisfactory amounts of Vancomycin-loaded fibers, as potential web dressing for wound repair


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Mateus Garcia Rodolfo ◽  
Lidiane Cristina Costa ◽  
Juliano Marini

Abstract Poly(lactic acid), PLA, is a biodegradable polymer obtained from renewable sources with similar properties when compared with petroleum-based thermoplastics but with inherent brittleness. In this work, the use of thermoplastic polyurethane (TPU) as toughening agent was evaluated. PLA/TPU blends with 25 and 50 wt% of TPU were produced in an internal mixer without the use of compatibilizers. Their thermal, rheological, and mechanical properties were analyzed and correlated with the developed morphology. Immiscible blends with dispersed droplets morphology were obtained, and it was observed an inversion between the matrix and dispersed phases with the increase of the TPU content. The presence of TPU altered the elasticity and viscosity of the blends when compared to PLA, besides acting as a nucleating agent. Huge increments in impact resistance (up to 365%) were achieved, indicating a great potential of TPU to be used as a PLA toughening agent.


2022 ◽  
Vol 58 (4) ◽  
pp. 250-260
Author(s):  
Dragos Alexandrescu ◽  
Iulian Antoniac ◽  
Cristian Olteanu ◽  
Lucretia Anghel ◽  
Nicolae Sarbu ◽  
...  

In the medical field the additive manufacturing process by fused deposition modeling has gained a great importance given the ability to create complex, organic geometries, in a short time period and the possibility of high customization. By fused deposition process the part is created layer by layer and the resulting part is characterized by high anisotropy, dictated mostly by printing parameters. To alleviate the anisotropy and to study the mechanical behavior of the 3D printed parts thermal processing is used. The materials used as filament is a poly (lactic acid) with copper particles embedded for antibacterial purposes. Samples were 3D printed using a commercial printer, thermally processed and tested in compression. On the failed specimens fracture investigations were performed to understand mechanical behavior during compression. The mechanical characteristics showed improvement and the anisotropy decreased as the processing temperature increased, but the samples became brittle. The mechanical behavior changed drastically on the thermally processed samples because of structural changes: a discontinuity between exterior layers and infill layers was created post layer fusion, the first region being the one stressed and failed first during tests.


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