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Gkougkousi K, Karantzalis AE, Nikolakopoulos PG, Dassios KG. Synergistic Effect of Carbon Micro/Nano-Fillers and Surface Patterning on the Superlubric Performance of 3D-Printed Structures. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1215. [PMID: 38473685 DOI: 10.3390/ma17051215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024]
Abstract
Superlubricity, the tribological regime where the coefficient of friction between two sliding surfaces almost vanishes, is currently being investigated as a viable route towards the energy efficiency envisioned by major long-term strategies for a sustainable future. This current study provides new insights towards the development of self-lubricating systems by material and topological design, systems which tend to exhibit near-superlubric tribological performance, by reporting the synergistic effect of selective surface patterning and presence of carbon micro/nano-fillers on the frictional coefficients of additively manufactured structures. Geometric and biomimetic surface patterns were prepared by fused deposition modelling (FDM), using printing filaments of a polymeric matrix infused with graphene nanoplatelets (GNPs) and carbon fibers (Cf). The calorimetric, spectroscopic, mechanical and optical microscopy characterization of the starting materials and as-printed structures provided fundamental insights for their tribological characterization under a ball-on-disk configuration. In geometrically patterned PLA-based structures, a graphene presence reduced the friction coefficient by ca. 8%, whereas PETG exhibited the lowest coefficients, in the vicinity of 0.1, indicating a high supelubric potential. Biomimetic patterns exhibited an inferior frictional response due to their topologically and tribologically anisotropy of the surfaces. Overall, a graphene presence in the starting materials demonstrated great potential for friction reduction, while PETG showed a tribological performance not only superior to PLA, but also compatible with superlubric performance. Methodological and technical challenges are discussed in the text.
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Affiliation(s)
- Katerina Gkougkousi
- Department of Chemical Engineering, University of Patras, Caratheodory 1, 26504 Patras, Greece
| | | | - Pantelis G Nikolakopoulos
- Department of Mechanical Engineering and Aeronautics, University of Patras, 26504 Rio Patras, Greece
| | - Konstantinos G Dassios
- Department of Chemical Engineering, University of Patras, Caratheodory 1, 26504 Patras, Greece
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Moura D, Rohringer S, Ferreira HP, Pereira AT, Barrias CC, Magalhães FD, Bergmeister H, Gonçalves IC. Long-term in vivo degradation and biocompatibility of degradable pHEMA hydrogels containing graphene oxide. Acta Biomater 2024; 173:351-364. [PMID: 37984630 DOI: 10.1016/j.actbio.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/31/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023]
Abstract
Developing biocompatible, non-fouling and biodegradable hydrogels for blood-contacting devices remains a demanding challenge. Such materials should promote natural healing, prevent clotting, and undergo controlled degradation. This study evaluates the biocompatibility and biodegradation of degradable poly(2-hydroxyethyl methacrylate) (d-pHEMA) hydrogels with or without reinforcement with oxidized few-layer graphene (d-pHEMA/M5ox) in a long term implantation in rats, assessing non-desired side-effects (irritation, chronic toxicity, immune response). Subcutaneous implantation over 6 months revealed degradation of both hydrogels, despite slower for d-pHEMA/M5ox, with degradation products found in intracellular vesicles. No inflammation nor infection at implantation areas were observed, and no histopathological findings were detected in parenchymal organs. Immunohistochemistry confirmed d-pHEMA and d-pHEMA/M5ox highly anti-adhesiveness. Gene expression of macrophages markers revealed presence of both M1 and M2 macrophages at all timepoints. M1/M2 profile after 6 months reveals an anti-inflammatory environment, suggesting no chronic inflammation, as also demonstrated by cytokines (IL-α, TNF-α and IL-10) analysis. Overall, modification of pHEMA towards a degradable material was successfully achieved without evoking a loss of its inherent properties, specially its anti-adhesiveness and biocompatibility. Therefore, these hydrogels hold potential as blank-slate for further modifications that promote cellular adhesion/proliferation for tissue engineering applications, namely for designing blood contacting devices with different load bearing requirements. STATEMENT OF SIGNIFICANCE: Biocompatibility, tunable biodegradation kinetics, and suitable immune response with lack of chronic toxicity and irritation, are key features in degradable blood contact devices that demand long-term exposure. We herein evaluate the 6-month in vivo performance of a degradable and hemocompatible anti-adhesive hydrogel based in pHEMA, and its mechanically reinforced formulation with few-layer graphene oxide. This subcutaneous implantation in a rat model, shows gradual degradation with progressive changes in material morphology, and no evidence of local inflammation in surrounding tissue, neither signs of inflammation or adverse reactions in systemic organs, suggesting biocompatibility of degradation products. Such hydrogels exhibit great potential as a blank slate for tissue engineering applications, including for blood contact, where cues for specific cells can be incorporated.
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Affiliation(s)
- Duarte Moura
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; FEUP - Faculdade de Engenharia, Departamento de Engenharia Metalúrgica e de Materiais, Universidade do Porto, Rua Dr. Roberto Frias, Porto 4200-465, Portugal
| | - Sabrina Rohringer
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | - Helena P Ferreira
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto 4050-313, Portugal
| | - Andreia T Pereira
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal
| | - Cristina C Barrias
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto 4050-313, Portugal
| | - Fernão D Magalhães
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto 4200-465, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto 4200-465, Portugal
| | - Helga Bergmeister
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute for Cardiovascular Research, Austria
| | - Inês C Gonçalves
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto 4200-180, Portugal.
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3
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Abir AA, Trindade B. A Comparative Study of Different Poly (Lactic Acid) Bio-Composites Produced by Mechanical Alloying and Casting for Tribological Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16041608. [PMID: 36837237 PMCID: PMC9959764 DOI: 10.3390/ma16041608] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 06/12/2023]
Abstract
The aim of this study was to fabricate different self-lubricating poly (lactic acid)-based bio-composites reinforced with mono- and multi-fillers of carbon fibers, graphene nanoparticles, and a soft Sn-based brazing alloy (Sn89-Zn8-Bi3) using a two-step process consisting of mechanical alloying followed by casting. The results showed that the incorporation of the different fillers on the PLA surface by mechanical alloying was quite homogenous. The volume ratio between the PLA and the fillers was 1:0.02, respectively. The PLA sample reinforced with short carbon fibers and graphene nanoparticles presented the highest hardness (84.5 Shore D, corresponding to a 10% increase compared to PLA) and the lowest specific wear rate (1.5 × 10-4 mm3/N·m, one order of magnitude lower than PLA). With regard to the coefficient of friction, the lowest value was obtained for the sample reinforced with graphene (0.43, corresponding to a decrease of 12% compared to PLA).
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Li S, Liao X, Xiao W, Jiang Q, Li G. The improved foaming behavior of PLA caused by the enhanced rheology properties and crystallization behavior via synergistic effect of carbon nanotubes and graphene. J Appl Polym Sci 2022. [DOI: 10.1002/app.51874] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shaojie Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu China
| | - Xia Liao
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu China
| | - Wei Xiao
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu China
| | - Qiuyue Jiang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu China
| | - Guangxian Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu China
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5
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Soo XYD, Wang S, Yeo CCJ, Li J, Ni XP, Jiang L, Xue K, Li Z, Fei X, Zhu Q, Loh XJ. Polylactic acid face masks: Are these the sustainable solutions in times of COVID-19 pandemic? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:151084. [PMID: 34678364 PMCID: PMC8531277 DOI: 10.1016/j.scitotenv.2021.151084] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 05/19/2023]
Abstract
The global massive consumption of disposable face masks driven by the ongoing COVID-19 pandemic has emerged as a blooming disaster to both the land and marine environment that might last for generations. Growing public concerns have been raised over the management and control of this new form of plastic pollution, and one of the proposed sustainable solution is to use renewable and/or biodegradable resources to develop mask materials in order to minimize their environmental impacts. As a representative biodegradable polymer, polylactic acid (PLA) has been proposed as a promising candidate to produce non-woven face masks instead of those fossil-based polymers. To further explore the feasibility of this alternative mask material, the present work aims to study both the hydrolytic and bio-degradation behaviors of pure PLA-derived 3-ply disposable face masks at ambient temperature. Hydrolytic degradability was investigated at different pH conditions of 2, 7 and 13 with the whole piece of face mask soaked for regular timed intervals up to 8 weeks. Weight loss study showed neutral and acidic conditions had minimal effect on PLA masks, but rapid degradation occurred under basic conditions in the first week with a sharp 25% decrease in weight that slowly tapered off, coupled with solution pH dropping from 13 to 9.6. This trend was supported by mechanical property, bacterial filtration efficiency (BFE) and particulate filtration efficiency (PFE) studies. Masks soaked in basic conditions had their modulus and tensile strength dropped by more than 50% after 8 weeks where the middle layer reached 68% and 90% respectively just after 48 h, and BFE and PFE decreased by 14% and 43% respectively after 4 weeks, which was much more significant than those in neutral and acidic conditions. Base degradation was also supported by nuclear magnetic resonance (NMR) and fourier transform infrared (FTIR), which disclosed that only the middle layer undergo major degradation with random chain scission and cleavage of enol or enolate chain ends, while outer and inner layers were much less affected. Scanning electron microscopy (SEM) attributed this observation to thinner PLA fibers for the middle layer of 3-7 μm diameter, which on average is 3 times smaller. This degradation was further supported by gel permeation chromatography (GPC) which saw an increase in lower molecular weight fragment Mw ~ 800 Da with soaking duration. The biodegradation behavior was studied under OECD 301F specification in sewage sludge environment. Similarly, degradation to the middle meltblown layer was more extensive, where the average weight loss and carbon loss was 25.8% and 25.7% respectively, double that of outer/inner spunbond layer. The results showed that the face masks did not completely disintegrate after 8 weeks, but small solubilized fragments of PLA formed in the biodegradation process can be completely mineralized into carbon dioxide without generation of secondary microplastic pollution in the environment. PLA masks are therefore a slightly greener option to consider in times of a pandemic that the world was caught unprepared; however future research on masks could be geared towards a higher degradability material that fully breaks down into non-harmful components while maintaining durability, filtration and protection properties for users.
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Affiliation(s)
- Xiang Yun Debbie Soo
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore
| | - Suxi Wang
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore
| | - Chee Chuan Jayven Yeo
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore
| | - Jiuwei Li
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, Singapore 637141, Singapore
| | - Xi Ping Ni
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore
| | - Lu Jiang
- School of Biomedicine and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, People's Republic of China
| | - Kun Xue
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore
| | - Zibiao Li
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore.
| | - Xunchang Fei
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, Singapore 637141, Singapore.
| | - Qiang Zhu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore.
| | - Xian Jun Loh
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore.
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Silva FALS, Costa-Almeida R, Timochenco L, Amaral SI, Pinto S, Gonçalves IC, Fernandes JR, Magalhães FD, Sarmento B, Pinto AM. Graphene Oxide Topical Administration: Skin Permeability Studies. MATERIALS (BASEL, SWITZERLAND) 2021; 14:2810. [PMID: 34070414 PMCID: PMC8197561 DOI: 10.3390/ma14112810] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 11/16/2022]
Abstract
Nanostructured carriers have been widely used in pharmaceutical formulations for dermatological treatment. They offer targeted drug delivery, sustained release, improved biostability, and low toxicity, usually presenting advantages over conventional formulations. Due to its large surface area, small size and photothermal properties, graphene oxide (GO) has the potential to be used for such applications. Nanographene oxide (GOn) presented average sizes of 197.6 ± 11.8 nm, and a surface charge of -39.4 ± 1.8 mV, being stable in water for over 6 months. 55.5% of the mass of GOn dispersion (at a concentration of 1000 µg mL-1) permeated the skin after 6 h of exposure. GOn dispersions have been shown to absorb near-infrared radiation, reaching temperatures up to 45.7 °C, within mild the photothermal therapy temperature range. Furthermore, GOn in amounts superior to those which could permeate the skin were shown not to affect human skin fibroblasts (HFF-1) morphology or viability, after 24 h of incubation. Due to its large size, no skin permeation was observed for graphite particles in aqueous dispersions stabilized with Pluronic P-123 (Gt-P-123). Altogether, for the first time, Gon's potential as a topic administration agent and for delivery of photothermal therapy has been demonstrated.
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Affiliation(s)
- Filipa A. L. S. Silva
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
| | - Raquel Costa-Almeida
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
| | - Licínia Timochenco
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, 4200-180 Porto, Portugal; (L.T.); (F.D.M.)
| | - Sara I. Amaral
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, 4200-180 Porto, Portugal; (L.T.); (F.D.M.)
| | - Soraia Pinto
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
- ICBAS–Instituto de Ciencias Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Inês C. Gonçalves
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
| | - José R. Fernandes
- CQVR–Centro de Química Vila Real, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal;
- Physical Department, University of Trás-os-Montes and Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal
| | - Fernão D. Magalhães
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, 4200-180 Porto, Portugal; (L.T.); (F.D.M.)
| | - Bruno Sarmento
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
- CESPU, IINFACTS–Institute for Research and Advanced Training in Health Sciences and Technologies, Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Artur M. Pinto
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal; (F.A.L.S.S.); (R.C.-A.); (S.I.A.); (S.P.); (I.C.G.); (B.S.)
- INEB—Instituto de Engénharia Biomedica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-180 Porto, Portugal
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, 4200-180 Porto, Portugal; (L.T.); (F.D.M.)
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Bijarimi M, Syuhada A, Zulaini N, Shahadah N, Alhadadi W, Ahmad MN, Ramli A, Normaya E. Poly(lactic acid)/Acrylonitrile Butadiene Styrene Nanocomposites with Hybrid Graphene Nanoplatelet/Organomontmorillonite: Effect of Processing Temperatures. INT POLYM PROC 2020. [DOI: 10.3139/217.3934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
This work reports the preparation and characterization of poly(lactic) acid/acrylonitrile butadiene styrene/graphene nanoplatelets/Cloisite C20A montmorillonite (PLA/ABS/GnP/C20A) nanocomposites via melt blending. The clay is hybridized with graphene to increase its dispersion in the polymer matrix. The melt processing temperatures play a vital role in the properties of the resulting nanocomposites in dictating the extent of thermal stability and dispersion of the fillers. The hybrid nanocomposites were characterized for stress-strain, thermal, chemical, and morphological properties. The findings were that there was an increase in the mechanical properties in terms of tensile strength and Young's modulus with the PLA/ABS/GnP/C20A at the high-temperature profile having the highest values of 43.1 MPa and 2533 MPa. The elongation at break increases slightly, due to the brittle properties of GnP. It was found that the dispersion of the fillers increased with increasing temperature profiles, as revealed by the morphological analysis by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The void size was also observed to be smaller and more homogenous with increasing temperature. However, in terms of thermal degradation analysis, the addition of fillers increases its thermal stability as the decomposition onset temperature increases by 22.5°C.
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Affiliation(s)
- M. Bijarimi
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - A. Syuhada
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - N. Zulaini
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - N. Shahadah
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - W. Alhadadi
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - M. N. Ahmad
- Experimental and Theoretical Research Laboratory , Department of Chemistry, Kulliyyah of Science, International Islamic University Malaysia, Kuantan, Pahang , Malaysia
| | - A. Ramli
- Faculty of Chemical & Natural Resources Engineering , Universiti Malaysia Pahang, Gambang, Pahang , Malaysia
| | - E. Normaya
- Experimental and Theoretical Research Laboratory , Department of Chemistry, Kulliyyah of Science, International Islamic University Malaysia, Kuantan, Pahang , Malaysia
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8
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Thalib NB, Mustapha SNH, Feng CK, Mustapha R. Tailoring graphene reinforced thermoset and biothermoset composites. REV CHEM ENG 2020. [DOI: 10.1515/revce-2017-0091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe surge of knowledge among researchers pertaining to the excellent properties of graphene has led to the utilisation of graphene as a reinforced filler in polymer composites. Different methods of graphene preparation, either bottom-up or top-down methods, are important requirements of starting materials in producing reinforced properties in the composites. The starting graphene material produced is either further functionalised or directly used as a filler in thermoset polymer matrixes. An effective interaction between graphene and polymer matrixes is important and can be achieved by incorporating graphene into a thermoset polymer matrix through melt mixing, solution mixing or in situ polymerisation processes. In addition, by taking into consideration the importance of green and sustainable composites, the details of previous work on graphene reinforced bio-thermoset polymer matrixes is discussed. The resultant mechanical and thermal properties of the composites were associated to the chemical interaction between the graphene filler and a thermoset matrix. Exploration for further variations of graphene polymer composites are discussed by taking the reinforcement properties in graphene composite as a starting point.
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Affiliation(s)
- Nur Bazilah Thalib
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia
| | - Siti Noor Hidayah Mustapha
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia
| | - Chong Kwok Feng
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia
| | - Rohani Mustapha
- School of Ocean Engineering, Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Terengganu, Malaysia
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9
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Borges I, Henriques PC, Gomes RN, Pinto AM, Pestana M, Magalhães FD, Gonçalves IC. Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E349. [PMID: 32085467 PMCID: PMC7075169 DOI: 10.3390/nano10020349] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/04/2020] [Accepted: 02/09/2020] [Indexed: 12/12/2022]
Abstract
Catheter-related infections are a common worldwide health problem, highlighting the need for antimicrobial catheters. Here, antibacterial potential of graphene nanoplatelets (GNP) incorporated in the commonly used polymer for catheter manufacture-polyurethane (PU)-is investigated. Two strategies are explored: melt-blending, producing a composite, and dip coating, where a composite layer is deposited on top of PU. GNP with different lateral sizes and oxidation degrees-GNP-M5, GNP-M15, GNP-M5ox, GNP-M15ox-are applied in both strategies, and the antimicrobial potential towards Staphylococcus epidermidis of GNP dispersions and GNP-containing PU evaluated. As dispersions, oxidized and smaller GNP powders (GNP-M5ox) inhibit 74% bacteria growth at 128 µg/mL. As surfaces, GNP exposure strongly impacts their antimicrobial profile: GNP absence at the surface of composites yields no significant effects on bacteria, while by varying GNP: PU ratio and GNP concentration, coatings enhance GNP exposure, depicting an antimicrobial profile. Oxidized GNP-containing coatings induce higher antibacterial effect than non-oxidized forms, particularly with smaller GNPox, where a homogeneous layer of fused platelets is formed on PU, leading to 70% reduction in bacterial adhesion and 70% bacterial death. This pioneering work unravels how to turn a polymer clinically used to produce catheters into an antimicrobial surface, crucial to reducing risk of infection associated with catheterization.
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Affiliation(s)
- Inês Borges
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Patrícia C. Henriques
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
- FEUP—Faculdade de Engenharia, Departamento de Engenharia Metalúrgica e de Materiais, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
- LEPABE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal;
| | - Rita N. Gomes
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Artur M. Pinto
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
- LEPABE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal;
| | - Manuel Pestana
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
- Department of Nephrology, São João Hospital Center, EPE, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Medicine, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Fernão D. Magalhães
- LEPABE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal;
| | - Inês C. Gonçalves
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; (I.B.); (P.C.H.); (R.N.G.); (M.P.)
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
- FEUP—Faculdade de Engenharia, Departamento de Engenharia Metalúrgica e de Materiais, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
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10
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Preparation and characterization of renewable composites from
Polylactide and Rice husk for 3D printing applications. JOURNAL OF POLYMER RESEARCH 2019. [DOI: 10.1007/s10965-019-1882-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Graphene modifies the biodegradation of poly(lactic acid)-thermoplastic cassava starch reactive blend films. Polym Degrad Stab 2019. [DOI: 10.1016/j.polymdegradstab.2019.04.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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Grząbka-Zasadzińska A, Klapiszewski Ł, Borysiak S, Jesionowski T. Thermal and Mechanical Properties of Silica⁻Lignin/Polylactide Composites Subjected to Biodegradation. MATERIALS 2018; 11:ma11112257. [PMID: 30428517 PMCID: PMC6266571 DOI: 10.3390/ma11112257] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/06/2018] [Accepted: 11/10/2018] [Indexed: 11/17/2022]
Abstract
In this paper, silica–lignin hybrid materials were used as fillers for a polylactide (PLA) matrix. In order to simulate biodegradation, PLA/hybrid filler composite films were kept in soil of neutral pH for six months. Differential scanning calorimetry (DSC) allowed analysis of nonisothermal crystallization behavior of composites, thermal analysis provided information about their thermal stability, and scanning electron microscopy (SEM) was applied to define morphology of films. The influence of biodegradation was also investigated in terms of changes in mechanical properties and color of samples. It was found that application of silica–lignin hybrids as fillers for PLA matrix may be interesting not only in terms of increasing thermal stability, but also controlled biodegradation. To the best knowledge of the authors, this is the first publication regarding biodegradation of PLA composites loaded with silica–lignin hybrid fillers.
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Affiliation(s)
- Aleksandra Grząbka-Zasadzińska
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland.
| | - Łukasz Klapiszewski
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland.
| | - Sławomir Borysiak
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland.
| | - Teofil Jesionowski
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland.
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13
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Botta L, Scaffaro R, Sutera F, Mistretta MC. Reprocessing of PLA/Graphene Nanoplatelets Nanocomposites. Polymers (Basel) 2017; 10:E18. [PMID: 30966053 PMCID: PMC6414878 DOI: 10.3390/polym10010018] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 11/17/2022] Open
Abstract
This work reports a study on the effect of multiple reprocessing on the properties of poly(lactic acid) (PLA) filled with graphene nanoplatelets (GnP) compared to the melt reprocessed neat polymeric matrix. In particular, morphological, X-Ray Diffraction and Micro-Raman analyses, intrinsic viscosity measurements, thermal, rheological and mechanical tests were carried out on materials reprocessed up five times by means of a single screw extruder. The results indicated that the presence of GnP decreased the degradation rate as a function of the reprocessing cycles in comparison with the neat PLA that, on the contrary, showed a more drastic reduction of the molecular weight. Moreover, the reprocessing improved the particle dispersion and reduced the presence of GnP aggregates.
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Affiliation(s)
- Luigi Botta
- Department of Civil, Environmental, Aerospace and Materials Engineering, University of Palermo, RU INSTM of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
| | - Roberto Scaffaro
- Department of Civil, Environmental, Aerospace and Materials Engineering, University of Palermo, RU INSTM of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
| | - Fiorenza Sutera
- Department of Civil, Environmental, Aerospace and Materials Engineering, University of Palermo, RU INSTM of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
| | - Maria Chiara Mistretta
- Department of Civil, Environmental, Aerospace and Materials Engineering, University of Palermo, RU INSTM of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
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14
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Arriagada P, Palza H, Palma P, Flores M, Caviedes P. Poly(lactic acid) composites based on graphene oxide particles with antibacterial behavior enhanced by electrical stimulus and biocompatibility. J Biomed Mater Res A 2017; 106:1051-1060. [PMID: 29218826 DOI: 10.1002/jbm.a.36307] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/07/2017] [Accepted: 12/04/2017] [Indexed: 01/19/2023]
Abstract
Poly(lactic acid) (PLA) is a biodegradable and biocompatible polyester widely used in biomedical applications. Unfortunately, this biomaterial suffers from some shortcomings related with the absence of both bioactivity and antibacterial capacity. In this work, composites of PLA with either graphene oxide (GO) or thermally reduced graphene oxide (TrGO) were prepared by melt mixing to overcome these limitations. PLA composites with both GO and TrGO inhibited the attachment and proliferation of Escherichia coli and Staphylococcus aureus bacteria depending on the kind and amount of filler. Noteworthy, it is shown that by applying an electrical stimulus to the percolated PLA/TrGO, the antibacterial behavior can be dramatically increased. MTT analysis showed that while all the PLA/GO composites were more cytocompatible to osteoblast-like cells (SaOS-2) than pure PLA, only low content of TrGO was able to increase this property. These tendencies were related with changes in the surface properties of the resulting polymer composites, such as polarity and roughness. In this way, the addition of GO and TrGO into a PLA matrix allows the development of multifunctional composites for potential applications in biomedicine. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1051-1060, 2018.
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Affiliation(s)
- Paulo Arriagada
- Laboratorio de polímeros, Depto. de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Humberto Palza
- Laboratorio de polímeros, Depto. de Ingeniería Química y Biotecnología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Patricia Palma
- Depto. Patología y Medicina Oral, Facultad de Odontología, Universidad de Chile, Sergio Livingstone 943, Santiago, Chile
| | - Marcos Flores
- Laboratory of Surfaces and Nanomaterials, Physics Department, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Pablo Caviedes
- Centro de Investigación Clínica y Estudios Farmacológicos, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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15
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Gonçalves C, Gonçalves IC, Magalhães FD, Pinto AM. Poly(lactic acid) Composites Containing Carbon-Based Nanomaterials: A Review. Polymers (Basel) 2017; 9:E269. [PMID: 30970948 PMCID: PMC6431974 DOI: 10.3390/polym9070269] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 06/30/2017] [Accepted: 07/04/2017] [Indexed: 11/27/2022] Open
Abstract
Poly(lactic acid) (PLA) is a green alternative to petrochemical commodity plastics, used in packaging, agricultural products, disposable materials, textiles, and automotive composites. It is also approved by regulatory authorities for several biomedical applications. However, for some uses it is required that some of its properties be improved, namely in terms of thermo-mechanical and electrical performance. The incorporation of nanofillers is a common approach to attain this goal. The outstanding properties of carbon-based nanomaterials (CBN) have caused a surge in research works dealing with PLA/CBN composites. The available information is compiled and reviewed, focusing on PLA/CNT (carbon nanotubes) and PLA/GBM (graphene-based materials) composites. The production methods, and the effects of CBN loading on PLA properties, namely mechanical, thermal, electrical, and biological, are discussed.
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Affiliation(s)
- Carolina Gonçalves
- LEPABE-Faculdade de Engenharia, Universidade do Porto, rua Dr. Roberto Frias, Porto 4200-465, Portugal.
| | - Inês C Gonçalves
- INEB-National Institute of Biomedical Engineering, University of Porto, Rua do Campo Alegre, 823, Porto 4150-180, Portugal.
- i3S-Institute for Innovation and Health Research, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal.
| | - Fernão D Magalhães
- LEPABE-Faculdade de Engenharia, Universidade do Porto, rua Dr. Roberto Frias, Porto 4200-465, Portugal.
| | - Artur M Pinto
- LEPABE-Faculdade de Engenharia, Universidade do Porto, rua Dr. Roberto Frias, Porto 4200-465, Portugal.
- INEB-National Institute of Biomedical Engineering, University of Porto, Rua do Campo Alegre, 823, Porto 4150-180, Portugal.
- i3S-Institute for Innovation and Health Research, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal.
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16
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Bayer IS. Thermomechanical Properties of Polylactic Acid-Graphene Composites: A State-of-the-Art Review for Biomedical Applications. MATERIALS (BASEL, SWITZERLAND) 2017; 10:E748. [PMID: 28773109 PMCID: PMC5551791 DOI: 10.3390/ma10070748] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 01/18/2023]
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.
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Affiliation(s)
- Ilker S Bayer
- Smart Materials, Istituto Italiano di Tecnologia, 16163 Genoa, Italy.
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