Thermomechanical Properties of Polylactic Acid-Graphene Composites: A State-of-the-Art Review for Biomedical Applications

Abstract

Due to its biodegradable and bioabsorbable characteristics polylactic acid (PLA) has attracted considerable attention for numerous biomedical applications. Moreover, a number of tissue engineering problems for function restoration of impaired tissues have been addressed by using PLA and its copolymers due to their biocompatibility and distinctive mechanical properties. Recent studies on various stereocomplex formation between enantiomeric PLA, poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) indicated that stereocomplexation enhances the mechanical properties as well as the thermal- and hydrolysis-resistance of PLA polymers. On the other hand, biomedical application of graphene is a relatively new front with significant potential. Many recent reports have indicated that understanding of graphene-cell (or tissue, organ) interactions; particularly the cellular uptake mechanisms are still challenging. Therefore, use of graphene or graphene oxide properly embedded in suitable PLA matrices can positively impact and accelerate the growth, differentiation, and proliferation of stem cells, conceivably minimizing concerns over cytotoxicity of graphene. As such, PLA-graphene composites hold great promise in tissue engineering, regenerative medicine, and in other biomedical fields. However, since PLA is classified as a hard bio-polyester prone to hydrolysis, understanding and engineering of thermo-mechanical properties of PLA-graphene composites are very crucial for such cutting-edge applications. Hence, this review aims to present an overview of current advances in the preparation and applications of PLA-graphene composites and their properties with focus on various biomedical uses such as scaffolds, drug delivery, cancer therapy, and biological imaging, together with a brief discussion on the challenges and perspectives for future research in this field.

Sustainable Electronics Based on Crop Plant Extracts and Graphene: A “Bioadvantaged” Approach

“…The conductive ink was first spray-coated on both sides of the cellulose membrane and, after solvent evaporation, the composite was hot-pressed at 190 °C (20 min) in order to infiltrate the blend inside the fiber network [18,21,38] and at the same time to form polyaleuritate in situ (see chemical characterization performed with Fourier transformed infrared spectroscopy (FTIR) in Figure S2, Supporting Information). [39] The comparison of the cross-sectional micromorphology of the cellulose membrane and the biocomposite in Figure 1d,e indicates that the impregnation does not create a thick layer (both thickness are about 40 µm) but rather embeds all the materials of the ink into the cellulose membrane bulk interlaces. Using thermogravimetric analysis (TGA), we ensured that none of the natural materials underwent thermal degradation due to hot-pressing conditions (see Figure S3, Supporting Information).…”

Development of Injection-Molded Polylactide Pieces with High Toughness by the Addition of Lactic Acid Oligomer and Characterization of Their Shape Memory Behavior

“…Polylactide (PLA) is a linear thermoplastic biodegradable polyester that can be obtained from starch-rich materials by fermentation to give lactide, which is polymerized at the industrial scale by ring-opening polymerization (ROP) [1]. PLA is a sound candidate to substitute some plastic commodities such as polypropylene (PP) or polystyrene (PS) in packaging applications [2][3][4][5][6], electronics [7], automotive [8], agriculture [9], textile, consumer goods, 3D printing applications [10][11][12][13], biomedical devices [14,15], pharmaceutical carriers [16,17], etc. The main advantage of PLA over As PLA is very sensitive to moisture, the biopolyester pellets were dried at 60 • C for 24 h. The OLA content varied in the 0-20 wt% at weight steps of 5 wt%.…”

Application of Artificial Intelligence in Modern Healthcare System

“…Electro-spinning for biomedicine is based on the application of natural substances and biopolymers, along with the mixture of drugs such as sulfisoxazole, naproxen, and essential oils with antibacterial properties such as eugenol and tocopherol. In recent times, there has been an enormous thrust in the usage of biopolymers for a number of applications, especially in the biomedical and also in pharmaceutical areas [51,52]. The functional effectiveness of the biopolymer molecules depends on the physicochemical properties, structural features, and composition [53].…”